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/kdb.h> 59 #include <sys/kernel.h> 60 #include <sys/kthread.h> 61 #include <sys/mac.h> 62 #include <sys/malloc.h> 63 #include <sys/mount.h> 64 #include <sys/namei.h> 65 #include <sys/reboot.h> 66 #include <sys/sleepqueue.h> 67 #include <sys/stat.h> 68 #include <sys/sysctl.h> 69 #include <sys/syslog.h> 70 #include <sys/vmmeter.h> 71 #include <sys/vnode.h> 72 73 #include <machine/stdarg.h> 74 75 #include <vm/vm.h> 76 #include <vm/vm_object.h> 77 #include <vm/vm_extern.h> 78 #include <vm/pmap.h> 79 #include <vm/vm_map.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_kern.h> 82 #include <vm/uma.h> 83 84 static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure"); 85 86 static void delmntque(struct vnode *vp); 87 static void insmntque(struct vnode *vp, struct mount *mp); 88 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 89 int slpflag, int slptimeo); 90 static void syncer_shutdown(void *arg, int howto); 91 static int vtryrecycle(struct vnode *vp); 92 static void vbusy(struct vnode *vp); 93 static void vdropl(struct vnode *vp); 94 static void vinactive(struct vnode *, struct thread *); 95 static void v_incr_usecount(struct vnode *); 96 static void v_decr_usecount(struct vnode *); 97 static void v_decr_useonly(struct vnode *); 98 static void v_upgrade_usecount(struct vnode *); 99 static void vfree(struct vnode *); 100 static void vnlru_free(int); 101 static void vdestroy(struct vnode *); 102 static void vgonel(struct vnode *); 103 static void vfs_knllock(void *arg); 104 static void vfs_knlunlock(void *arg); 105 static int vfs_knllocked(void *arg); 106 107 108 /* 109 * Enable Giant pushdown based on whether or not the vm is mpsafe in this 110 * build. Without mpsafevm the buffer cache can not run Giant free. 111 */ 112 #if defined(__alpha__) || defined(__amd64__) || defined(__i386__) || \ 113 defined(__ia64__) || defined(__sparc64__) 114 int mpsafe_vfs = 1; 115 #else 116 int mpsafe_vfs; 117 #endif 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, never decreased. 125 */ 126 static unsigned long numvnodes; 127 128 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 129 130 /* 131 * Conversion tables for conversion from vnode types to inode formats 132 * and back. 133 */ 134 enum vtype iftovt_tab[16] = { 135 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 136 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 137 }; 138 int vttoif_tab[10] = { 139 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 140 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 141 }; 142 143 /* 144 * List of vnodes that are ready for recycling. 145 */ 146 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 147 148 /* 149 * Free vnode target. Free vnodes may simply be files which have been stat'd 150 * but not read. This is somewhat common, and a small cache of such files 151 * should be kept to avoid recreation costs. 152 */ 153 static u_long wantfreevnodes; 154 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 155 /* Number of vnodes in the free list. */ 156 static u_long freevnodes; 157 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 158 159 /* 160 * Various variables used for debugging the new implementation of 161 * reassignbuf(). 162 * XXX these are probably of (very) limited utility now. 163 */ 164 static int reassignbufcalls; 165 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 166 167 /* 168 * Cache for the mount type id assigned to NFS. This is used for 169 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 170 */ 171 int nfs_mount_type = -1; 172 173 /* To keep more than one thread at a time from running vfs_getnewfsid */ 174 static struct mtx mntid_mtx; 175 176 /* 177 * Lock for any access to the following: 178 * vnode_free_list 179 * numvnodes 180 * freevnodes 181 */ 182 static struct mtx vnode_free_list_mtx; 183 184 /* Publicly exported FS */ 185 struct nfs_public nfs_pub; 186 187 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 188 static uma_zone_t vnode_zone; 189 static uma_zone_t vnodepoll_zone; 190 191 /* Set to 1 to print out reclaim of active vnodes */ 192 int prtactive; 193 194 /* 195 * The workitem queue. 196 * 197 * It is useful to delay writes of file data and filesystem metadata 198 * for tens of seconds so that quickly created and deleted files need 199 * not waste disk bandwidth being created and removed. To realize this, 200 * we append vnodes to a "workitem" queue. When running with a soft 201 * updates implementation, most pending metadata dependencies should 202 * not wait for more than a few seconds. Thus, mounted on block devices 203 * are delayed only about a half the time that file data is delayed. 204 * Similarly, directory updates are more critical, so are only delayed 205 * about a third the time that file data is delayed. Thus, there are 206 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 207 * one each second (driven off the filesystem syncer process). The 208 * syncer_delayno variable indicates the next queue that is to be processed. 209 * Items that need to be processed soon are placed in this queue: 210 * 211 * syncer_workitem_pending[syncer_delayno] 212 * 213 * A delay of fifteen seconds is done by placing the request fifteen 214 * entries later in the queue: 215 * 216 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 217 * 218 */ 219 static int syncer_delayno; 220 static long syncer_mask; 221 LIST_HEAD(synclist, bufobj); 222 static struct synclist *syncer_workitem_pending; 223 /* 224 * The sync_mtx protects: 225 * bo->bo_synclist 226 * sync_vnode_count 227 * syncer_delayno 228 * syncer_state 229 * syncer_workitem_pending 230 * syncer_worklist_len 231 * rushjob 232 */ 233 static struct mtx sync_mtx; 234 235 #define SYNCER_MAXDELAY 32 236 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 237 static int syncdelay = 30; /* max time to delay syncing data */ 238 static int filedelay = 30; /* time to delay syncing files */ 239 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 240 static int dirdelay = 29; /* time to delay syncing directories */ 241 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 242 static int metadelay = 28; /* time to delay syncing metadata */ 243 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 244 static int rushjob; /* number of slots to run ASAP */ 245 static int stat_rush_requests; /* number of times I/O speeded up */ 246 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 247 248 /* 249 * When shutting down the syncer, run it at four times normal speed. 250 */ 251 #define SYNCER_SHUTDOWN_SPEEDUP 4 252 static int sync_vnode_count; 253 static int syncer_worklist_len; 254 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 255 syncer_state; 256 257 /* 258 * Number of vnodes we want to exist at any one time. This is mostly used 259 * to size hash tables in vnode-related code. It is normally not used in 260 * getnewvnode(), as wantfreevnodes is normally nonzero.) 261 * 262 * XXX desiredvnodes is historical cruft and should not exist. 263 */ 264 int desiredvnodes; 265 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 266 &desiredvnodes, 0, "Maximum number of vnodes"); 267 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 268 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)"); 269 static int vnlru_nowhere; 270 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 271 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 272 273 /* 274 * Macros to control when a vnode is freed and recycled. All require 275 * the vnode interlock. 276 */ 277 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 278 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 279 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt) 280 281 282 /* 283 * Initialize the vnode management data structures. 284 */ 285 #ifndef MAXVNODES_MAX 286 #define MAXVNODES_MAX 100000 287 #endif 288 static void 289 vntblinit(void *dummy __unused) 290 { 291 292 /* 293 * Desiredvnodes is a function of the physical memory size and 294 * the kernel's heap size. Specifically, desiredvnodes scales 295 * in proportion to the physical memory size until two fifths 296 * of the kernel's heap size is consumed by vnodes and vm 297 * objects. 298 */ 299 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / 300 (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); 301 if (desiredvnodes > MAXVNODES_MAX) { 302 if (bootverbose) 303 printf("Reducing kern.maxvnodes %d -> %d\n", 304 desiredvnodes, MAXVNODES_MAX); 305 desiredvnodes = MAXVNODES_MAX; 306 } 307 wantfreevnodes = desiredvnodes / 4; 308 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 309 TAILQ_INIT(&vnode_free_list); 310 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 311 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 312 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 313 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 314 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 315 /* 316 * Initialize the filesystem syncer. 317 */ 318 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 319 &syncer_mask); 320 syncer_maxdelay = syncer_mask + 1; 321 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 322 } 323 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 324 325 326 /* 327 * Mark a mount point as busy. Used to synchronize access and to delay 328 * unmounting. Interlock is not released on failure. 329 */ 330 int 331 vfs_busy(struct mount *mp, int flags, struct mtx *interlkp, 332 struct thread *td) 333 { 334 int lkflags; 335 336 MNT_ILOCK(mp); 337 MNT_REF(mp); 338 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 339 if (flags & LK_NOWAIT) { 340 MNT_REL(mp); 341 MNT_IUNLOCK(mp); 342 return (ENOENT); 343 } 344 if (interlkp) 345 mtx_unlock(interlkp); 346 mp->mnt_kern_flag |= MNTK_MWAIT; 347 /* 348 * Since all busy locks are shared except the exclusive 349 * lock granted when unmounting, the only place that a 350 * wakeup needs to be done is at the release of the 351 * exclusive lock at the end of dounmount. 352 */ 353 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0); 354 MNT_REL(mp); 355 MNT_IUNLOCK(mp); 356 if (interlkp) 357 mtx_lock(interlkp); 358 return (ENOENT); 359 } 360 if (interlkp) 361 mtx_unlock(interlkp); 362 lkflags = LK_SHARED | LK_INTERLOCK; 363 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td)) 364 panic("vfs_busy: unexpected lock failure"); 365 vfs_rel(mp); 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 } 378 379 /* 380 * Lookup a mount point by filesystem identifier. 381 */ 382 struct mount * 383 vfs_getvfs(fsid_t *fsid) 384 { 385 struct mount *mp; 386 387 mtx_lock(&mountlist_mtx); 388 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 389 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 390 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 391 mtx_unlock(&mountlist_mtx); 392 return (mp); 393 } 394 } 395 mtx_unlock(&mountlist_mtx); 396 return ((struct mount *) 0); 397 } 398 399 /* 400 * Check if a user can access priveledged mount options. 401 */ 402 int 403 vfs_suser(struct mount *mp, struct thread *td) 404 { 405 int error; 406 407 if ((mp->mnt_flag & MNT_USER) == 0 || 408 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 409 if ((error = suser(td)) != 0) 410 return (error); 411 } 412 return (0); 413 } 414 415 /* 416 * Get a new unique fsid. Try to make its val[0] unique, since this value 417 * will be used to create fake device numbers for stat(). Also try (but 418 * not so hard) make its val[0] unique mod 2^16, since some emulators only 419 * support 16-bit device numbers. We end up with unique val[0]'s for the 420 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 421 * 422 * Keep in mind that several mounts may be running in parallel. Starting 423 * the search one past where the previous search terminated is both a 424 * micro-optimization and a defense against returning the same fsid to 425 * different mounts. 426 */ 427 void 428 vfs_getnewfsid(struct mount *mp) 429 { 430 static u_int16_t mntid_base; 431 fsid_t tfsid; 432 int mtype; 433 434 mtx_lock(&mntid_mtx); 435 mtype = mp->mnt_vfc->vfc_typenum; 436 tfsid.val[1] = mtype; 437 mtype = (mtype & 0xFF) << 24; 438 for (;;) { 439 tfsid.val[0] = makedev(255, 440 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 441 mntid_base++; 442 if (vfs_getvfs(&tfsid) == NULL) 443 break; 444 } 445 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 446 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 447 mtx_unlock(&mntid_mtx); 448 } 449 450 /* 451 * Knob to control the precision of file timestamps: 452 * 453 * 0 = seconds only; nanoseconds zeroed. 454 * 1 = seconds and nanoseconds, accurate within 1/HZ. 455 * 2 = seconds and nanoseconds, truncated to microseconds. 456 * >=3 = seconds and nanoseconds, maximum precision. 457 */ 458 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 459 460 static int timestamp_precision = TSP_SEC; 461 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 462 ×tamp_precision, 0, ""); 463 464 /* 465 * Get a current timestamp. 466 */ 467 void 468 vfs_timestamp(struct timespec *tsp) 469 { 470 struct timeval tv; 471 472 switch (timestamp_precision) { 473 case TSP_SEC: 474 tsp->tv_sec = time_second; 475 tsp->tv_nsec = 0; 476 break; 477 case TSP_HZ: 478 getnanotime(tsp); 479 break; 480 case TSP_USEC: 481 microtime(&tv); 482 TIMEVAL_TO_TIMESPEC(&tv, tsp); 483 break; 484 case TSP_NSEC: 485 default: 486 nanotime(tsp); 487 break; 488 } 489 } 490 491 /* 492 * Set vnode attributes to VNOVAL 493 */ 494 void 495 vattr_null(struct vattr *vap) 496 { 497 498 vap->va_type = VNON; 499 vap->va_size = VNOVAL; 500 vap->va_bytes = VNOVAL; 501 vap->va_mode = VNOVAL; 502 vap->va_nlink = VNOVAL; 503 vap->va_uid = VNOVAL; 504 vap->va_gid = VNOVAL; 505 vap->va_fsid = VNOVAL; 506 vap->va_fileid = VNOVAL; 507 vap->va_blocksize = VNOVAL; 508 vap->va_rdev = VNOVAL; 509 vap->va_atime.tv_sec = VNOVAL; 510 vap->va_atime.tv_nsec = VNOVAL; 511 vap->va_mtime.tv_sec = VNOVAL; 512 vap->va_mtime.tv_nsec = VNOVAL; 513 vap->va_ctime.tv_sec = VNOVAL; 514 vap->va_ctime.tv_nsec = VNOVAL; 515 vap->va_birthtime.tv_sec = VNOVAL; 516 vap->va_birthtime.tv_nsec = VNOVAL; 517 vap->va_flags = VNOVAL; 518 vap->va_gen = VNOVAL; 519 vap->va_vaflags = 0; 520 } 521 522 /* 523 * This routine is called when we have too many vnodes. It attempts 524 * to free <count> vnodes and will potentially free vnodes that still 525 * have VM backing store (VM backing store is typically the cause 526 * of a vnode blowout so we want to do this). Therefore, this operation 527 * is not considered cheap. 528 * 529 * A number of conditions may prevent a vnode from being reclaimed. 530 * the buffer cache may have references on the vnode, a directory 531 * vnode may still have references due to the namei cache representing 532 * underlying files, or the vnode may be in active use. It is not 533 * desireable to reuse such vnodes. These conditions may cause the 534 * number of vnodes to reach some minimum value regardless of what 535 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 536 */ 537 static int 538 vlrureclaim(struct mount *mp) 539 { 540 struct thread *td; 541 struct vnode *vp; 542 int done; 543 int trigger; 544 int usevnodes; 545 int count; 546 547 /* 548 * Calculate the trigger point, don't allow user 549 * screwups to blow us up. This prevents us from 550 * recycling vnodes with lots of resident pages. We 551 * aren't trying to free memory, we are trying to 552 * free vnodes. 553 */ 554 usevnodes = desiredvnodes; 555 if (usevnodes <= 0) 556 usevnodes = 1; 557 trigger = cnt.v_page_count * 2 / usevnodes; 558 done = 0; 559 td = curthread; 560 vn_start_write(NULL, &mp, V_WAIT); 561 MNT_ILOCK(mp); 562 count = mp->mnt_nvnodelistsize / 10 + 1; 563 while (count != 0) { 564 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 565 while (vp != NULL && vp->v_type == VMARKER) 566 vp = TAILQ_NEXT(vp, v_nmntvnodes); 567 if (vp == NULL) 568 break; 569 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 570 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 571 --count; 572 if (!VI_TRYLOCK(vp)) 573 goto next_iter; 574 /* 575 * If it's been deconstructed already, it's still 576 * referenced, or it exceeds the trigger, skip it. 577 */ 578 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || 579 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 580 vp->v_object->resident_page_count > trigger)) { 581 VI_UNLOCK(vp); 582 goto next_iter; 583 } 584 MNT_IUNLOCK(mp); 585 vholdl(vp); 586 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) { 587 vdrop(vp); 588 goto next_iter_mntunlocked; 589 } 590 VI_LOCK(vp); 591 /* 592 * v_usecount may have been bumped after VOP_LOCK() dropped 593 * the vnode interlock and before it was locked again. 594 * 595 * It is not necessary to recheck VI_DOOMED because it can 596 * only be set by another thread that holds both the vnode 597 * lock and vnode interlock. If another thread has the 598 * vnode lock before we get to VOP_LOCK() and obtains the 599 * vnode interlock after VOP_LOCK() drops the vnode 600 * interlock, the other thread will be unable to drop the 601 * vnode lock before our VOP_LOCK() call fails. 602 */ 603 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || 604 (vp->v_object != NULL && 605 vp->v_object->resident_page_count > trigger)) { 606 VOP_UNLOCK(vp, LK_INTERLOCK, td); 607 goto next_iter_mntunlocked; 608 } 609 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 610 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 611 vgonel(vp); 612 VOP_UNLOCK(vp, 0, td); 613 vdropl(vp); 614 done++; 615 next_iter_mntunlocked: 616 if ((count % 256) != 0) 617 goto relock_mnt; 618 goto yield; 619 next_iter: 620 if ((count % 256) != 0) 621 continue; 622 MNT_IUNLOCK(mp); 623 yield: 624 uio_yield(); 625 relock_mnt: 626 MNT_ILOCK(mp); 627 } 628 MNT_IUNLOCK(mp); 629 vn_finished_write(mp); 630 return done; 631 } 632 633 /* 634 * Attempt to keep the free list at wantfreevnodes length. 635 */ 636 static void 637 vnlru_free(int count) 638 { 639 struct vnode *vp; 640 641 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 642 for (; count > 0; count--) { 643 vp = TAILQ_FIRST(&vnode_free_list); 644 /* 645 * The list can be modified while the free_list_mtx 646 * has been dropped and vp could be NULL here. 647 */ 648 if (!vp) 649 break; 650 VNASSERT(vp->v_op != NULL, vp, 651 ("vnlru_free: vnode already reclaimed.")); 652 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 653 /* 654 * Don't recycle if we can't get the interlock. 655 */ 656 if (!VI_TRYLOCK(vp)) { 657 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 658 continue; 659 } 660 VNASSERT(VCANRECYCLE(vp), vp, 661 ("vp inconsistent on freelist")); 662 freevnodes--; 663 vp->v_iflag &= ~VI_FREE; 664 vholdl(vp); 665 mtx_unlock(&vnode_free_list_mtx); 666 VI_UNLOCK(vp); 667 vtryrecycle(vp); 668 /* 669 * If the recycled succeeded this vdrop will actually free 670 * the vnode. If not it will simply place it back on 671 * the free list. 672 */ 673 vdrop(vp); 674 mtx_lock(&vnode_free_list_mtx); 675 } 676 } 677 /* 678 * Attempt to recycle vnodes in a context that is always safe to block. 679 * Calling vlrurecycle() from the bowels of filesystem code has some 680 * interesting deadlock problems. 681 */ 682 static struct proc *vnlruproc; 683 static int vnlruproc_sig; 684 685 static void 686 vnlru_proc(void) 687 { 688 struct mount *mp, *nmp; 689 int done; 690 struct proc *p = vnlruproc; 691 struct thread *td = FIRST_THREAD_IN_PROC(p); 692 693 mtx_lock(&Giant); 694 695 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 696 SHUTDOWN_PRI_FIRST); 697 698 for (;;) { 699 kthread_suspend_check(p); 700 mtx_lock(&vnode_free_list_mtx); 701 if (freevnodes > wantfreevnodes) 702 vnlru_free(freevnodes - wantfreevnodes); 703 if (numvnodes <= desiredvnodes * 9 / 10) { 704 vnlruproc_sig = 0; 705 wakeup(&vnlruproc_sig); 706 msleep(vnlruproc, &vnode_free_list_mtx, 707 PVFS|PDROP, "vlruwt", hz); 708 continue; 709 } 710 mtx_unlock(&vnode_free_list_mtx); 711 done = 0; 712 mtx_lock(&mountlist_mtx); 713 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 714 int vfsunlocked; 715 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 716 nmp = TAILQ_NEXT(mp, mnt_list); 717 continue; 718 } 719 if (!VFS_NEEDSGIANT(mp)) { 720 mtx_unlock(&Giant); 721 vfsunlocked = 1; 722 } else 723 vfsunlocked = 0; 724 done += vlrureclaim(mp); 725 if (vfsunlocked) 726 mtx_lock(&Giant); 727 mtx_lock(&mountlist_mtx); 728 nmp = TAILQ_NEXT(mp, mnt_list); 729 vfs_unbusy(mp, td); 730 } 731 mtx_unlock(&mountlist_mtx); 732 if (done == 0) { 733 #if 0 734 /* These messages are temporary debugging aids */ 735 if (vnlru_nowhere < 5) 736 printf("vnlru process getting nowhere..\n"); 737 else if (vnlru_nowhere == 5) 738 printf("vnlru process messages stopped.\n"); 739 #endif 740 vnlru_nowhere++; 741 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 742 } else 743 uio_yield(); 744 } 745 } 746 747 static struct kproc_desc vnlru_kp = { 748 "vnlru", 749 vnlru_proc, 750 &vnlruproc 751 }; 752 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 753 754 /* 755 * Routines having to do with the management of the vnode table. 756 */ 757 758 static void 759 vdestroy(struct vnode *vp) 760 { 761 struct bufobj *bo; 762 763 CTR1(KTR_VFS, "vdestroy vp %p", vp); 764 mtx_lock(&vnode_free_list_mtx); 765 numvnodes--; 766 mtx_unlock(&vnode_free_list_mtx); 767 bo = &vp->v_bufobj; 768 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 769 ("cleaned vnode still on the free list.")); 770 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 771 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 772 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 773 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 774 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 775 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 776 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL")); 777 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 778 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL")); 779 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 780 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 781 VI_UNLOCK(vp); 782 #ifdef MAC 783 mac_destroy_vnode(vp); 784 #endif 785 if (vp->v_pollinfo != NULL) { 786 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note); 787 mtx_destroy(&vp->v_pollinfo->vpi_lock); 788 uma_zfree(vnodepoll_zone, vp->v_pollinfo); 789 } 790 #ifdef INVARIANTS 791 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */ 792 vp->v_op = NULL; 793 #endif 794 lockdestroy(vp->v_vnlock); 795 mtx_destroy(&vp->v_interlock); 796 uma_zfree(vnode_zone, vp); 797 } 798 799 /* 800 * Try to recycle a freed vnode. We abort if anyone picks up a reference 801 * before we actually vgone(). This function must be called with the vnode 802 * held to prevent the vnode from being returned to the free list midway 803 * through vgone(). 804 */ 805 static int 806 vtryrecycle(struct vnode *vp) 807 { 808 struct thread *td = curthread; 809 struct mount *vnmp; 810 811 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp); 812 VNASSERT(vp->v_holdcnt, vp, 813 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 814 /* 815 * This vnode may found and locked via some other list, if so we 816 * can't recycle it yet. 817 */ 818 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 819 return (EWOULDBLOCK); 820 /* 821 * Don't recycle if its filesystem is being suspended. 822 */ 823 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 824 VOP_UNLOCK(vp, 0, td); 825 return (EBUSY); 826 } 827 /* 828 * If we got this far, we need to acquire the interlock and see if 829 * anyone picked up this vnode from another list. If not, we will 830 * mark it with DOOMED via vgonel() so that anyone who does find it 831 * will skip over it. 832 */ 833 VI_LOCK(vp); 834 if (vp->v_usecount) { 835 VOP_UNLOCK(vp, LK_INTERLOCK, td); 836 vn_finished_write(vnmp); 837 return (EBUSY); 838 } 839 if ((vp->v_iflag & VI_DOOMED) == 0) 840 vgonel(vp); 841 VOP_UNLOCK(vp, LK_INTERLOCK, td); 842 vn_finished_write(vnmp); 843 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp); 844 return (0); 845 } 846 847 /* 848 * Return the next vnode from the free list. 849 */ 850 int 851 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 852 struct vnode **vpp) 853 { 854 struct vnode *vp = NULL; 855 struct bufobj *bo; 856 857 mtx_lock(&vnode_free_list_mtx); 858 /* 859 * Lend our context to reclaim vnodes if they've exceeded the max. 860 */ 861 if (freevnodes > wantfreevnodes) 862 vnlru_free(1); 863 /* 864 * Wait for available vnodes. 865 */ 866 if (numvnodes > desiredvnodes) { 867 if (vnlruproc_sig == 0) { 868 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 869 wakeup(vnlruproc); 870 } 871 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 872 "vlruwk", hz); 873 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 874 if (numvnodes > desiredvnodes) { 875 mtx_unlock(&vnode_free_list_mtx); 876 return (ENFILE); 877 } 878 #endif 879 } 880 numvnodes++; 881 mtx_unlock(&vnode_free_list_mtx); 882 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 883 /* 884 * Setup locks. 885 */ 886 vp->v_vnlock = &vp->v_lock; 887 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 888 /* 889 * By default, don't allow shared locks unless filesystems 890 * opt-in. 891 */ 892 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE); 893 /* 894 * Initialize bufobj. 895 */ 896 bo = &vp->v_bufobj; 897 bo->__bo_vnode = vp; 898 bo->bo_mtx = &vp->v_interlock; 899 bo->bo_ops = &buf_ops_bio; 900 bo->bo_private = vp; 901 TAILQ_INIT(&bo->bo_clean.bv_hd); 902 TAILQ_INIT(&bo->bo_dirty.bv_hd); 903 /* 904 * Initialize namecache. 905 */ 906 LIST_INIT(&vp->v_cache_src); 907 TAILQ_INIT(&vp->v_cache_dst); 908 /* 909 * Finalize various vnode identity bits. 910 */ 911 vp->v_type = VNON; 912 vp->v_tag = tag; 913 vp->v_op = vops; 914 v_incr_usecount(vp); 915 vp->v_data = 0; 916 #ifdef MAC 917 mac_init_vnode(vp); 918 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 919 mac_associate_vnode_singlelabel(mp, vp); 920 else if (mp == NULL) 921 printf("NULL mp in getnewvnode()\n"); 922 #endif 923 if (mp != NULL) { 924 insmntque(vp, mp); 925 bo->bo_bsize = mp->mnt_stat.f_iosize; 926 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 927 vp->v_vflag |= VV_NOKNOTE; 928 } 929 930 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp); 931 *vpp = vp; 932 return (0); 933 } 934 935 /* 936 * Delete from old mount point vnode list, if on one. 937 */ 938 static void 939 delmntque(struct vnode *vp) 940 { 941 struct mount *mp; 942 943 mp = vp->v_mount; 944 if (mp == NULL) 945 return; 946 MNT_ILOCK(mp); 947 vp->v_mount = NULL; 948 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 949 ("bad mount point vnode list size")); 950 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 951 mp->mnt_nvnodelistsize--; 952 MNT_REL(mp); 953 MNT_IUNLOCK(mp); 954 } 955 956 /* 957 * Insert into list of vnodes for the new mount point, if available. 958 */ 959 static void 960 insmntque(struct vnode *vp, struct mount *mp) 961 { 962 963 vp->v_mount = mp; 964 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 965 MNT_ILOCK(mp); 966 MNT_REF(mp); 967 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 968 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 969 ("neg mount point vnode list size")); 970 mp->mnt_nvnodelistsize++; 971 MNT_IUNLOCK(mp); 972 } 973 974 /* 975 * Flush out and invalidate all buffers associated with a bufobj 976 * Called with the underlying object locked. 977 */ 978 int 979 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, 980 int slptimeo) 981 { 982 int error; 983 984 BO_LOCK(bo); 985 if (flags & V_SAVE) { 986 error = bufobj_wwait(bo, slpflag, slptimeo); 987 if (error) { 988 BO_UNLOCK(bo); 989 return (error); 990 } 991 if (bo->bo_dirty.bv_cnt > 0) { 992 BO_UNLOCK(bo); 993 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0) 994 return (error); 995 /* 996 * XXX We could save a lock/unlock if this was only 997 * enabled under INVARIANTS 998 */ 999 BO_LOCK(bo); 1000 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1001 panic("vinvalbuf: dirty bufs"); 1002 } 1003 } 1004 /* 1005 * If you alter this loop please notice that interlock is dropped and 1006 * reacquired in flushbuflist. Special care is needed to ensure that 1007 * no race conditions occur from this. 1008 */ 1009 do { 1010 error = flushbuflist(&bo->bo_clean, 1011 flags, bo, slpflag, slptimeo); 1012 if (error == 0) 1013 error = flushbuflist(&bo->bo_dirty, 1014 flags, bo, slpflag, slptimeo); 1015 if (error != 0 && error != EAGAIN) { 1016 BO_UNLOCK(bo); 1017 return (error); 1018 } 1019 } while (error != 0); 1020 1021 /* 1022 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1023 * have write I/O in-progress but if there is a VM object then the 1024 * VM object can also have read-I/O in-progress. 1025 */ 1026 do { 1027 bufobj_wwait(bo, 0, 0); 1028 BO_UNLOCK(bo); 1029 if (bo->bo_object != NULL) { 1030 VM_OBJECT_LOCK(bo->bo_object); 1031 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1032 VM_OBJECT_UNLOCK(bo->bo_object); 1033 } 1034 BO_LOCK(bo); 1035 } while (bo->bo_numoutput > 0); 1036 BO_UNLOCK(bo); 1037 1038 /* 1039 * Destroy the copy in the VM cache, too. 1040 */ 1041 if (bo->bo_object != NULL) { 1042 VM_OBJECT_LOCK(bo->bo_object); 1043 vm_object_page_remove(bo->bo_object, 0, 0, 1044 (flags & V_SAVE) ? TRUE : FALSE); 1045 VM_OBJECT_UNLOCK(bo->bo_object); 1046 } 1047 1048 #ifdef INVARIANTS 1049 BO_LOCK(bo); 1050 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1051 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1052 panic("vinvalbuf: flush failed"); 1053 BO_UNLOCK(bo); 1054 #endif 1055 return (0); 1056 } 1057 1058 /* 1059 * Flush out and invalidate all buffers associated with a vnode. 1060 * Called with the underlying object locked. 1061 */ 1062 int 1063 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, 1064 int slptimeo) 1065 { 1066 1067 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags); 1068 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1069 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo)); 1070 } 1071 1072 /* 1073 * Flush out buffers on the specified list. 1074 * 1075 */ 1076 static int 1077 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1078 int slptimeo) 1079 { 1080 struct buf *bp, *nbp; 1081 int retval, error; 1082 daddr_t lblkno; 1083 b_xflags_t xflags; 1084 1085 ASSERT_BO_LOCKED(bo); 1086 1087 retval = 0; 1088 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1089 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1090 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1091 continue; 1092 } 1093 lblkno = 0; 1094 xflags = 0; 1095 if (nbp != NULL) { 1096 lblkno = nbp->b_lblkno; 1097 xflags = nbp->b_xflags & 1098 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); 1099 } 1100 retval = EAGAIN; 1101 error = BUF_TIMELOCK(bp, 1102 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), 1103 "flushbuf", slpflag, slptimeo); 1104 if (error) { 1105 BO_LOCK(bo); 1106 return (error != ENOLCK ? error : EAGAIN); 1107 } 1108 KASSERT(bp->b_bufobj == bo, 1109 ("bp %p wrong b_bufobj %p should be %p", 1110 bp, bp->b_bufobj, bo)); 1111 if (bp->b_bufobj != bo) { /* XXX: necessary ? */ 1112 BUF_UNLOCK(bp); 1113 BO_LOCK(bo); 1114 return (EAGAIN); 1115 } 1116 /* 1117 * XXX Since there are no node locks for NFS, I 1118 * believe there is a slight chance that a delayed 1119 * write will occur while sleeping just above, so 1120 * check for it. 1121 */ 1122 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1123 (flags & V_SAVE)) { 1124 bremfree(bp); 1125 bp->b_flags |= B_ASYNC; 1126 bwrite(bp); 1127 BO_LOCK(bo); 1128 return (EAGAIN); /* XXX: why not loop ? */ 1129 } 1130 bremfree(bp); 1131 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1132 bp->b_flags &= ~B_ASYNC; 1133 brelse(bp); 1134 BO_LOCK(bo); 1135 if (nbp != NULL && 1136 (nbp->b_bufobj != bo || 1137 nbp->b_lblkno != lblkno || 1138 (nbp->b_xflags & 1139 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1140 break; /* nbp invalid */ 1141 } 1142 return (retval); 1143 } 1144 1145 /* 1146 * Truncate a file's buffer and pages to a specified length. This 1147 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1148 * sync activity. 1149 */ 1150 int 1151 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, 1152 off_t length, int blksize) 1153 { 1154 struct buf *bp, *nbp; 1155 int anyfreed; 1156 int trunclbn; 1157 struct bufobj *bo; 1158 1159 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length); 1160 /* 1161 * Round up to the *next* lbn. 1162 */ 1163 trunclbn = (length + blksize - 1) / blksize; 1164 1165 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1166 restart: 1167 VI_LOCK(vp); 1168 bo = &vp->v_bufobj; 1169 anyfreed = 1; 1170 for (;anyfreed;) { 1171 anyfreed = 0; 1172 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1173 if (bp->b_lblkno < trunclbn) 1174 continue; 1175 if (BUF_LOCK(bp, 1176 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1177 VI_MTX(vp)) == ENOLCK) 1178 goto restart; 1179 1180 bremfree(bp); 1181 bp->b_flags |= (B_INVAL | B_RELBUF); 1182 bp->b_flags &= ~B_ASYNC; 1183 brelse(bp); 1184 anyfreed = 1; 1185 1186 if (nbp != NULL && 1187 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1188 (nbp->b_vp != vp) || 1189 (nbp->b_flags & B_DELWRI))) { 1190 goto restart; 1191 } 1192 VI_LOCK(vp); 1193 } 1194 1195 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1196 if (bp->b_lblkno < trunclbn) 1197 continue; 1198 if (BUF_LOCK(bp, 1199 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1200 VI_MTX(vp)) == ENOLCK) 1201 goto restart; 1202 bremfree(bp); 1203 bp->b_flags |= (B_INVAL | B_RELBUF); 1204 bp->b_flags &= ~B_ASYNC; 1205 brelse(bp); 1206 anyfreed = 1; 1207 if (nbp != NULL && 1208 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1209 (nbp->b_vp != vp) || 1210 (nbp->b_flags & B_DELWRI) == 0)) { 1211 goto restart; 1212 } 1213 VI_LOCK(vp); 1214 } 1215 } 1216 1217 if (length > 0) { 1218 restartsync: 1219 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1220 if (bp->b_lblkno > 0) 1221 continue; 1222 /* 1223 * Since we hold the vnode lock this should only 1224 * fail if we're racing with the buf daemon. 1225 */ 1226 if (BUF_LOCK(bp, 1227 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1228 VI_MTX(vp)) == ENOLCK) { 1229 goto restart; 1230 } 1231 VNASSERT((bp->b_flags & B_DELWRI), vp, 1232 ("buf(%p) on dirty queue without DELWRI", bp)); 1233 1234 bremfree(bp); 1235 bawrite(bp); 1236 VI_LOCK(vp); 1237 goto restartsync; 1238 } 1239 } 1240 1241 bufobj_wwait(bo, 0, 0); 1242 VI_UNLOCK(vp); 1243 vnode_pager_setsize(vp, length); 1244 1245 return (0); 1246 } 1247 1248 /* 1249 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1250 * a vnode. 1251 * 1252 * NOTE: We have to deal with the special case of a background bitmap 1253 * buffer, a situation where two buffers will have the same logical 1254 * block offset. We want (1) only the foreground buffer to be accessed 1255 * in a lookup and (2) must differentiate between the foreground and 1256 * background buffer in the splay tree algorithm because the splay 1257 * tree cannot normally handle multiple entities with the same 'index'. 1258 * We accomplish this by adding differentiating flags to the splay tree's 1259 * numerical domain. 1260 */ 1261 static 1262 struct buf * 1263 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1264 { 1265 struct buf dummy; 1266 struct buf *lefttreemax, *righttreemin, *y; 1267 1268 if (root == NULL) 1269 return (NULL); 1270 lefttreemax = righttreemin = &dummy; 1271 for (;;) { 1272 if (lblkno < root->b_lblkno || 1273 (lblkno == root->b_lblkno && 1274 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1275 if ((y = root->b_left) == NULL) 1276 break; 1277 if (lblkno < y->b_lblkno) { 1278 /* Rotate right. */ 1279 root->b_left = y->b_right; 1280 y->b_right = root; 1281 root = y; 1282 if ((y = root->b_left) == NULL) 1283 break; 1284 } 1285 /* Link into the new root's right tree. */ 1286 righttreemin->b_left = root; 1287 righttreemin = root; 1288 } else if (lblkno > root->b_lblkno || 1289 (lblkno == root->b_lblkno && 1290 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1291 if ((y = root->b_right) == NULL) 1292 break; 1293 if (lblkno > y->b_lblkno) { 1294 /* Rotate left. */ 1295 root->b_right = y->b_left; 1296 y->b_left = root; 1297 root = y; 1298 if ((y = root->b_right) == NULL) 1299 break; 1300 } 1301 /* Link into the new root's left tree. */ 1302 lefttreemax->b_right = root; 1303 lefttreemax = root; 1304 } else { 1305 break; 1306 } 1307 root = y; 1308 } 1309 /* Assemble the new root. */ 1310 lefttreemax->b_right = root->b_left; 1311 righttreemin->b_left = root->b_right; 1312 root->b_left = dummy.b_right; 1313 root->b_right = dummy.b_left; 1314 return (root); 1315 } 1316 1317 static void 1318 buf_vlist_remove(struct buf *bp) 1319 { 1320 struct buf *root; 1321 struct bufv *bv; 1322 1323 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1324 ASSERT_BO_LOCKED(bp->b_bufobj); 1325 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1326 (BX_VNDIRTY|BX_VNCLEAN), 1327 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1328 if (bp->b_xflags & BX_VNDIRTY) 1329 bv = &bp->b_bufobj->bo_dirty; 1330 else 1331 bv = &bp->b_bufobj->bo_clean; 1332 if (bp != bv->bv_root) { 1333 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1334 KASSERT(root == bp, ("splay lookup failed in remove")); 1335 } 1336 if (bp->b_left == NULL) { 1337 root = bp->b_right; 1338 } else { 1339 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1340 root->b_right = bp->b_right; 1341 } 1342 bv->bv_root = root; 1343 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1344 bv->bv_cnt--; 1345 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1346 } 1347 1348 /* 1349 * Add the buffer to the sorted clean or dirty block list using a 1350 * splay tree algorithm. 1351 * 1352 * NOTE: xflags is passed as a constant, optimizing this inline function! 1353 */ 1354 static void 1355 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1356 { 1357 struct buf *root; 1358 struct bufv *bv; 1359 1360 ASSERT_BO_LOCKED(bo); 1361 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1362 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1363 bp->b_xflags |= xflags; 1364 if (xflags & BX_VNDIRTY) 1365 bv = &bo->bo_dirty; 1366 else 1367 bv = &bo->bo_clean; 1368 1369 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1370 if (root == NULL) { 1371 bp->b_left = NULL; 1372 bp->b_right = NULL; 1373 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1374 } else if (bp->b_lblkno < root->b_lblkno || 1375 (bp->b_lblkno == root->b_lblkno && 1376 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1377 bp->b_left = root->b_left; 1378 bp->b_right = root; 1379 root->b_left = NULL; 1380 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1381 } else { 1382 bp->b_right = root->b_right; 1383 bp->b_left = root; 1384 root->b_right = NULL; 1385 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1386 } 1387 bv->bv_cnt++; 1388 bv->bv_root = bp; 1389 } 1390 1391 /* 1392 * Lookup a buffer using the splay tree. Note that we specifically avoid 1393 * shadow buffers used in background bitmap writes. 1394 * 1395 * This code isn't quite efficient as it could be because we are maintaining 1396 * two sorted lists and do not know which list the block resides in. 1397 * 1398 * During a "make buildworld" the desired buffer is found at one of 1399 * the roots more than 60% of the time. Thus, checking both roots 1400 * before performing either splay eliminates unnecessary splays on the 1401 * first tree splayed. 1402 */ 1403 struct buf * 1404 gbincore(struct bufobj *bo, daddr_t lblkno) 1405 { 1406 struct buf *bp; 1407 1408 ASSERT_BO_LOCKED(bo); 1409 if ((bp = bo->bo_clean.bv_root) != NULL && 1410 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1411 return (bp); 1412 if ((bp = bo->bo_dirty.bv_root) != NULL && 1413 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1414 return (bp); 1415 if ((bp = bo->bo_clean.bv_root) != NULL) { 1416 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1417 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1418 return (bp); 1419 } 1420 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1421 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1422 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1423 return (bp); 1424 } 1425 return (NULL); 1426 } 1427 1428 /* 1429 * Associate a buffer with a vnode. 1430 */ 1431 void 1432 bgetvp(struct vnode *vp, struct buf *bp) 1433 { 1434 1435 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1436 1437 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1438 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1439 ("bgetvp: bp already attached! %p", bp)); 1440 1441 ASSERT_VI_LOCKED(vp, "bgetvp"); 1442 vholdl(vp); 1443 bp->b_vp = vp; 1444 bp->b_bufobj = &vp->v_bufobj; 1445 /* 1446 * Insert onto list for new vnode. 1447 */ 1448 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); 1449 } 1450 1451 /* 1452 * Disassociate a buffer from a vnode. 1453 */ 1454 void 1455 brelvp(struct buf *bp) 1456 { 1457 struct bufobj *bo; 1458 struct vnode *vp; 1459 1460 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1461 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1462 1463 /* 1464 * Delete from old vnode list, if on one. 1465 */ 1466 vp = bp->b_vp; /* XXX */ 1467 bo = bp->b_bufobj; 1468 BO_LOCK(bo); 1469 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1470 buf_vlist_remove(bp); 1471 else 1472 panic("brelvp: Buffer %p not on queue.", bp); 1473 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1474 bo->bo_flag &= ~BO_ONWORKLST; 1475 mtx_lock(&sync_mtx); 1476 LIST_REMOVE(bo, bo_synclist); 1477 syncer_worklist_len--; 1478 mtx_unlock(&sync_mtx); 1479 } 1480 bp->b_vp = NULL; 1481 bp->b_bufobj = NULL; 1482 vdropl(vp); 1483 } 1484 1485 /* 1486 * Add an item to the syncer work queue. 1487 */ 1488 static void 1489 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1490 { 1491 int slot; 1492 1493 ASSERT_BO_LOCKED(bo); 1494 1495 mtx_lock(&sync_mtx); 1496 if (bo->bo_flag & BO_ONWORKLST) 1497 LIST_REMOVE(bo, bo_synclist); 1498 else { 1499 bo->bo_flag |= BO_ONWORKLST; 1500 syncer_worklist_len++; 1501 } 1502 1503 if (delay > syncer_maxdelay - 2) 1504 delay = syncer_maxdelay - 2; 1505 slot = (syncer_delayno + delay) & syncer_mask; 1506 1507 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); 1508 mtx_unlock(&sync_mtx); 1509 } 1510 1511 static int 1512 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1513 { 1514 int error, len; 1515 1516 mtx_lock(&sync_mtx); 1517 len = syncer_worklist_len - sync_vnode_count; 1518 mtx_unlock(&sync_mtx); 1519 error = SYSCTL_OUT(req, &len, sizeof(len)); 1520 return (error); 1521 } 1522 1523 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1524 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1525 1526 static struct proc *updateproc; 1527 static void sched_sync(void); 1528 static struct kproc_desc up_kp = { 1529 "syncer", 1530 sched_sync, 1531 &updateproc 1532 }; 1533 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1534 1535 static int 1536 sync_vnode(struct bufobj *bo, struct thread *td) 1537 { 1538 struct vnode *vp; 1539 struct mount *mp; 1540 1541 vp = bo->__bo_vnode; /* XXX */ 1542 if (VOP_ISLOCKED(vp, NULL) != 0) 1543 return (1); 1544 if (VI_TRYLOCK(vp) == 0) 1545 return (1); 1546 /* 1547 * We use vhold in case the vnode does not 1548 * successfully sync. vhold prevents the vnode from 1549 * going away when we unlock the sync_mtx so that 1550 * we can acquire the vnode interlock. 1551 */ 1552 vholdl(vp); 1553 mtx_unlock(&sync_mtx); 1554 VI_UNLOCK(vp); 1555 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1556 vdrop(vp); 1557 mtx_lock(&sync_mtx); 1558 return (1); 1559 } 1560 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1561 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1562 VOP_UNLOCK(vp, 0, td); 1563 vn_finished_write(mp); 1564 VI_LOCK(vp); 1565 if ((bo->bo_flag & BO_ONWORKLST) != 0) { 1566 /* 1567 * Put us back on the worklist. The worklist 1568 * routine will remove us from our current 1569 * position and then add us back in at a later 1570 * position. 1571 */ 1572 vn_syncer_add_to_worklist(bo, syncdelay); 1573 } 1574 vdropl(vp); 1575 mtx_lock(&sync_mtx); 1576 return (0); 1577 } 1578 1579 /* 1580 * System filesystem synchronizer daemon. 1581 */ 1582 static void 1583 sched_sync(void) 1584 { 1585 struct synclist *next; 1586 struct synclist *slp; 1587 struct bufobj *bo; 1588 long starttime; 1589 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); 1590 static int dummychan; 1591 int last_work_seen; 1592 int net_worklist_len; 1593 int syncer_final_iter; 1594 int first_printf; 1595 int error; 1596 1597 mtx_lock(&Giant); 1598 last_work_seen = 0; 1599 syncer_final_iter = 0; 1600 first_printf = 1; 1601 syncer_state = SYNCER_RUNNING; 1602 starttime = time_uptime; 1603 td->td_pflags |= TDP_NORUNNINGBUF; 1604 1605 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1606 SHUTDOWN_PRI_LAST); 1607 1608 for (;;) { 1609 mtx_lock(&sync_mtx); 1610 if (syncer_state == SYNCER_FINAL_DELAY && 1611 syncer_final_iter == 0) { 1612 mtx_unlock(&sync_mtx); 1613 kthread_suspend_check(td->td_proc); 1614 mtx_lock(&sync_mtx); 1615 } 1616 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1617 if (syncer_state != SYNCER_RUNNING && 1618 starttime != time_uptime) { 1619 if (first_printf) { 1620 printf("\nSyncing disks, vnodes remaining..."); 1621 first_printf = 0; 1622 } 1623 printf("%d ", net_worklist_len); 1624 } 1625 starttime = time_uptime; 1626 1627 /* 1628 * Push files whose dirty time has expired. Be careful 1629 * of interrupt race on slp queue. 1630 * 1631 * Skip over empty worklist slots when shutting down. 1632 */ 1633 do { 1634 slp = &syncer_workitem_pending[syncer_delayno]; 1635 syncer_delayno += 1; 1636 if (syncer_delayno == syncer_maxdelay) 1637 syncer_delayno = 0; 1638 next = &syncer_workitem_pending[syncer_delayno]; 1639 /* 1640 * If the worklist has wrapped since the 1641 * it was emptied of all but syncer vnodes, 1642 * switch to the FINAL_DELAY state and run 1643 * for one more second. 1644 */ 1645 if (syncer_state == SYNCER_SHUTTING_DOWN && 1646 net_worklist_len == 0 && 1647 last_work_seen == syncer_delayno) { 1648 syncer_state = SYNCER_FINAL_DELAY; 1649 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1650 } 1651 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1652 syncer_worklist_len > 0); 1653 1654 /* 1655 * Keep track of the last time there was anything 1656 * on the worklist other than syncer vnodes. 1657 * Return to the SHUTTING_DOWN state if any 1658 * new work appears. 1659 */ 1660 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1661 last_work_seen = syncer_delayno; 1662 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1663 syncer_state = SYNCER_SHUTTING_DOWN; 1664 while ((bo = LIST_FIRST(slp)) != NULL) { 1665 error = sync_vnode(bo, td); 1666 if (error == 1) { 1667 LIST_REMOVE(bo, bo_synclist); 1668 LIST_INSERT_HEAD(next, bo, bo_synclist); 1669 continue; 1670 } 1671 } 1672 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1673 syncer_final_iter--; 1674 mtx_unlock(&sync_mtx); 1675 /* 1676 * The variable rushjob allows the kernel to speed up the 1677 * processing of the filesystem syncer process. A rushjob 1678 * value of N tells the filesystem syncer to process the next 1679 * N seconds worth of work on its queue ASAP. Currently rushjob 1680 * is used by the soft update code to speed up the filesystem 1681 * syncer process when the incore state is getting so far 1682 * ahead of the disk that the kernel memory pool is being 1683 * threatened with exhaustion. 1684 */ 1685 mtx_lock(&sync_mtx); 1686 if (rushjob > 0) { 1687 rushjob -= 1; 1688 mtx_unlock(&sync_mtx); 1689 continue; 1690 } 1691 mtx_unlock(&sync_mtx); 1692 /* 1693 * Just sleep for a short period if time between 1694 * iterations when shutting down to allow some I/O 1695 * to happen. 1696 * 1697 * If it has taken us less than a second to process the 1698 * current work, then wait. Otherwise start right over 1699 * again. We can still lose time if any single round 1700 * takes more than two seconds, but it does not really 1701 * matter as we are just trying to generally pace the 1702 * filesystem activity. 1703 */ 1704 if (syncer_state != SYNCER_RUNNING) 1705 tsleep(&dummychan, PPAUSE, "syncfnl", 1706 hz / SYNCER_SHUTDOWN_SPEEDUP); 1707 else if (time_uptime == starttime) 1708 tsleep(&lbolt, PPAUSE, "syncer", 0); 1709 } 1710 } 1711 1712 /* 1713 * Request the syncer daemon to speed up its work. 1714 * We never push it to speed up more than half of its 1715 * normal turn time, otherwise it could take over the cpu. 1716 */ 1717 int 1718 speedup_syncer() 1719 { 1720 struct thread *td; 1721 int ret = 0; 1722 1723 td = FIRST_THREAD_IN_PROC(updateproc); 1724 sleepq_remove(td, &lbolt); 1725 mtx_lock(&sync_mtx); 1726 if (rushjob < syncdelay / 2) { 1727 rushjob += 1; 1728 stat_rush_requests += 1; 1729 ret = 1; 1730 } 1731 mtx_unlock(&sync_mtx); 1732 return (ret); 1733 } 1734 1735 /* 1736 * Tell the syncer to speed up its work and run though its work 1737 * list several times, then tell it to shut down. 1738 */ 1739 static void 1740 syncer_shutdown(void *arg, int howto) 1741 { 1742 struct thread *td; 1743 1744 if (howto & RB_NOSYNC) 1745 return; 1746 td = FIRST_THREAD_IN_PROC(updateproc); 1747 sleepq_remove(td, &lbolt); 1748 mtx_lock(&sync_mtx); 1749 syncer_state = SYNCER_SHUTTING_DOWN; 1750 rushjob = 0; 1751 mtx_unlock(&sync_mtx); 1752 kproc_shutdown(arg, howto); 1753 } 1754 1755 /* 1756 * Reassign a buffer from one vnode to another. 1757 * Used to assign file specific control information 1758 * (indirect blocks) to the vnode to which they belong. 1759 */ 1760 void 1761 reassignbuf(struct buf *bp) 1762 { 1763 struct vnode *vp; 1764 struct bufobj *bo; 1765 int delay; 1766 #ifdef INVARIANTS 1767 struct bufv *bv; 1768 #endif 1769 1770 vp = bp->b_vp; 1771 bo = bp->b_bufobj; 1772 ++reassignbufcalls; 1773 1774 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 1775 bp, bp->b_vp, bp->b_flags); 1776 /* 1777 * B_PAGING flagged buffers cannot be reassigned because their vp 1778 * is not fully linked in. 1779 */ 1780 if (bp->b_flags & B_PAGING) 1781 panic("cannot reassign paging buffer"); 1782 1783 /* 1784 * Delete from old vnode list, if on one. 1785 */ 1786 VI_LOCK(vp); 1787 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1788 buf_vlist_remove(bp); 1789 else 1790 panic("reassignbuf: Buffer %p not on queue.", bp); 1791 /* 1792 * If dirty, put on list of dirty buffers; otherwise insert onto list 1793 * of clean buffers. 1794 */ 1795 if (bp->b_flags & B_DELWRI) { 1796 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 1797 switch (vp->v_type) { 1798 case VDIR: 1799 delay = dirdelay; 1800 break; 1801 case VCHR: 1802 delay = metadelay; 1803 break; 1804 default: 1805 delay = filedelay; 1806 } 1807 vn_syncer_add_to_worklist(bo, delay); 1808 } 1809 buf_vlist_add(bp, bo, BX_VNDIRTY); 1810 } else { 1811 buf_vlist_add(bp, bo, BX_VNCLEAN); 1812 1813 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1814 mtx_lock(&sync_mtx); 1815 LIST_REMOVE(bo, bo_synclist); 1816 syncer_worklist_len--; 1817 mtx_unlock(&sync_mtx); 1818 bo->bo_flag &= ~BO_ONWORKLST; 1819 } 1820 } 1821 #ifdef INVARIANTS 1822 bv = &bo->bo_clean; 1823 bp = TAILQ_FIRST(&bv->bv_hd); 1824 KASSERT(bp == NULL || bp->b_bufobj == bo, 1825 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1826 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1827 KASSERT(bp == NULL || bp->b_bufobj == bo, 1828 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1829 bv = &bo->bo_dirty; 1830 bp = TAILQ_FIRST(&bv->bv_hd); 1831 KASSERT(bp == NULL || bp->b_bufobj == bo, 1832 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1833 bp = TAILQ_LAST(&bv->bv_hd, buflists); 1834 KASSERT(bp == NULL || bp->b_bufobj == bo, 1835 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 1836 #endif 1837 VI_UNLOCK(vp); 1838 } 1839 1840 /* 1841 * Increment the use and hold counts on the vnode, taking care to reference 1842 * the driver's usecount if this is a chardev. The vholdl() will remove 1843 * the vnode from the free list if it is presently free. Requires the 1844 * vnode interlock and returns with it held. 1845 */ 1846 static void 1847 v_incr_usecount(struct vnode *vp) 1848 { 1849 1850 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n", 1851 vp, vp->v_holdcnt, vp->v_usecount); 1852 vp->v_usecount++; 1853 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1854 dev_lock(); 1855 vp->v_rdev->si_usecount++; 1856 dev_unlock(); 1857 } 1858 vholdl(vp); 1859 } 1860 1861 /* 1862 * Turn a holdcnt into a use+holdcnt such that only one call to 1863 * v_decr_usecount is needed. 1864 */ 1865 static void 1866 v_upgrade_usecount(struct vnode *vp) 1867 { 1868 1869 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n", 1870 vp, vp->v_holdcnt, vp->v_usecount); 1871 vp->v_usecount++; 1872 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1873 dev_lock(); 1874 vp->v_rdev->si_usecount++; 1875 dev_unlock(); 1876 } 1877 } 1878 1879 /* 1880 * Decrement the vnode use and hold count along with the driver's usecount 1881 * if this is a chardev. The vdropl() below releases the vnode interlock 1882 * as it may free the vnode. 1883 */ 1884 static void 1885 v_decr_usecount(struct vnode *vp) 1886 { 1887 1888 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n", 1889 vp, vp->v_holdcnt, vp->v_usecount); 1890 ASSERT_VI_LOCKED(vp, __FUNCTION__); 1891 VNASSERT(vp->v_usecount > 0, vp, 1892 ("v_decr_usecount: negative usecount")); 1893 vp->v_usecount--; 1894 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1895 dev_lock(); 1896 vp->v_rdev->si_usecount--; 1897 dev_unlock(); 1898 } 1899 vdropl(vp); 1900 } 1901 1902 /* 1903 * Decrement only the use count and driver use count. This is intended to 1904 * be paired with a follow on vdropl() to release the remaining hold count. 1905 * In this way we may vgone() a vnode with a 0 usecount without risk of 1906 * having it end up on a free list because the hold count is kept above 0. 1907 */ 1908 static void 1909 v_decr_useonly(struct vnode *vp) 1910 { 1911 1912 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n", 1913 vp, vp->v_holdcnt, vp->v_usecount); 1914 ASSERT_VI_LOCKED(vp, __FUNCTION__); 1915 VNASSERT(vp->v_usecount > 0, vp, 1916 ("v_decr_useonly: negative usecount")); 1917 vp->v_usecount--; 1918 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 1919 dev_lock(); 1920 vp->v_rdev->si_usecount--; 1921 dev_unlock(); 1922 } 1923 } 1924 1925 /* 1926 * Grab a particular vnode from the free list, increment its 1927 * reference count and lock it. The vnode lock bit is set if the 1928 * vnode is being eliminated in vgone. The process is awakened 1929 * when the transition is completed, and an error returned to 1930 * indicate that the vnode is no longer usable (possibly having 1931 * been changed to a new filesystem type). 1932 */ 1933 int 1934 vget(struct vnode *vp, int flags, struct thread *td) 1935 { 1936 int oweinact; 1937 int oldflags; 1938 int error; 1939 1940 error = 0; 1941 oldflags = flags; 1942 oweinact = 0; 1943 VFS_ASSERT_GIANT(vp->v_mount); 1944 if ((flags & LK_INTERLOCK) == 0) 1945 VI_LOCK(vp); 1946 /* 1947 * If the inactive call was deferred because vput() was called 1948 * with a shared lock, we have to do it here before another thread 1949 * gets a reference to data that should be dead. 1950 */ 1951 if (vp->v_iflag & VI_OWEINACT) { 1952 if (flags & LK_NOWAIT) { 1953 VI_UNLOCK(vp); 1954 return (EBUSY); 1955 } 1956 flags &= ~LK_TYPE_MASK; 1957 flags |= LK_EXCLUSIVE; 1958 oweinact = 1; 1959 } 1960 vholdl(vp); 1961 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1962 vdrop(vp); 1963 return (error); 1964 } 1965 VI_LOCK(vp); 1966 /* Upgrade our holdcnt to a usecount. */ 1967 v_upgrade_usecount(vp); 1968 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 1969 panic("vget: vn_lock failed to return ENOENT\n"); 1970 if (oweinact) { 1971 if (vp->v_iflag & VI_OWEINACT) 1972 vinactive(vp, td); 1973 VI_UNLOCK(vp); 1974 if ((oldflags & LK_TYPE_MASK) == 0) 1975 VOP_UNLOCK(vp, 0, td); 1976 } else 1977 VI_UNLOCK(vp); 1978 return (0); 1979 } 1980 1981 /* 1982 * Increase the reference count of a vnode. 1983 */ 1984 void 1985 vref(struct vnode *vp) 1986 { 1987 1988 VI_LOCK(vp); 1989 v_incr_usecount(vp); 1990 VI_UNLOCK(vp); 1991 } 1992 1993 /* 1994 * Return reference count of a vnode. 1995 * 1996 * The results of this call are only guaranteed when some mechanism other 1997 * than the VI lock is used to stop other processes from gaining references 1998 * to the vnode. This may be the case if the caller holds the only reference. 1999 * This is also useful when stale data is acceptable as race conditions may 2000 * be accounted for by some other means. 2001 */ 2002 int 2003 vrefcnt(struct vnode *vp) 2004 { 2005 int usecnt; 2006 2007 VI_LOCK(vp); 2008 usecnt = vp->v_usecount; 2009 VI_UNLOCK(vp); 2010 2011 return (usecnt); 2012 } 2013 2014 2015 /* 2016 * Vnode put/release. 2017 * If count drops to zero, call inactive routine and return to freelist. 2018 */ 2019 void 2020 vrele(struct vnode *vp) 2021 { 2022 struct thread *td = curthread; /* XXX */ 2023 2024 KASSERT(vp != NULL, ("vrele: null vp")); 2025 VFS_ASSERT_GIANT(vp->v_mount); 2026 2027 VI_LOCK(vp); 2028 2029 /* Skip this v_writecount check if we're going to panic below. */ 2030 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2031 ("vrele: missed vn_close")); 2032 2033 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2034 vp->v_usecount == 1)) { 2035 v_decr_usecount(vp); 2036 return; 2037 } 2038 if (vp->v_usecount != 1) { 2039 #ifdef DIAGNOSTIC 2040 vprint("vrele: negative ref count", vp); 2041 #endif 2042 VI_UNLOCK(vp); 2043 panic("vrele: negative ref cnt"); 2044 } 2045 /* 2046 * We want to hold the vnode until the inactive finishes to 2047 * prevent vgone() races. We drop the use count here and the 2048 * hold count below when we're done. 2049 */ 2050 v_decr_useonly(vp); 2051 /* 2052 * We must call VOP_INACTIVE with the node locked. Mark 2053 * as VI_DOINGINACT to avoid recursion. 2054 */ 2055 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 2056 VI_LOCK(vp); 2057 vinactive(vp, td); 2058 VOP_UNLOCK(vp, 0, td); 2059 } else 2060 VI_LOCK(vp); 2061 vdropl(vp); 2062 } 2063 2064 /* 2065 * Release an already locked vnode. This give the same effects as 2066 * unlock+vrele(), but takes less time and avoids releasing and 2067 * re-aquiring the lock (as vrele() aquires the lock internally.) 2068 */ 2069 void 2070 vput(struct vnode *vp) 2071 { 2072 struct thread *td = curthread; /* XXX */ 2073 int error; 2074 2075 KASSERT(vp != NULL, ("vput: null vp")); 2076 ASSERT_VOP_LOCKED(vp, "vput"); 2077 VFS_ASSERT_GIANT(vp->v_mount); 2078 VI_LOCK(vp); 2079 /* Skip this v_writecount check if we're going to panic below. */ 2080 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2081 ("vput: missed vn_close")); 2082 error = 0; 2083 2084 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2085 vp->v_usecount == 1)) { 2086 VOP_UNLOCK(vp, 0, td); 2087 v_decr_usecount(vp); 2088 return; 2089 } 2090 2091 if (vp->v_usecount != 1) { 2092 #ifdef DIAGNOSTIC 2093 vprint("vput: negative ref count", vp); 2094 #endif 2095 panic("vput: negative ref cnt"); 2096 } 2097 /* 2098 * We want to hold the vnode until the inactive finishes to 2099 * prevent vgone() races. We drop the use count here and the 2100 * hold count below when we're done. 2101 */ 2102 v_decr_useonly(vp); 2103 vp->v_iflag |= VI_OWEINACT; 2104 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) { 2105 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td); 2106 VI_LOCK(vp); 2107 if (error) 2108 goto done; 2109 } 2110 if (vp->v_iflag & VI_OWEINACT) 2111 vinactive(vp, td); 2112 VOP_UNLOCK(vp, 0, td); 2113 done: 2114 vdropl(vp); 2115 } 2116 2117 /* 2118 * Somebody doesn't want the vnode recycled. 2119 */ 2120 void 2121 vhold(struct vnode *vp) 2122 { 2123 2124 VI_LOCK(vp); 2125 vholdl(vp); 2126 VI_UNLOCK(vp); 2127 } 2128 2129 void 2130 vholdl(struct vnode *vp) 2131 { 2132 2133 vp->v_holdcnt++; 2134 if (VSHOULDBUSY(vp)) 2135 vbusy(vp); 2136 } 2137 2138 /* 2139 * Note that there is one less who cares about this vnode. vdrop() is the 2140 * opposite of vhold(). 2141 */ 2142 void 2143 vdrop(struct vnode *vp) 2144 { 2145 2146 VI_LOCK(vp); 2147 vdropl(vp); 2148 } 2149 2150 /* 2151 * Drop the hold count of the vnode. If this is the last reference to 2152 * the vnode we will free it if it has been vgone'd otherwise it is 2153 * placed on the free list. 2154 */ 2155 static void 2156 vdropl(struct vnode *vp) 2157 { 2158 2159 if (vp->v_holdcnt <= 0) 2160 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2161 vp->v_holdcnt--; 2162 if (vp->v_holdcnt == 0) { 2163 if (vp->v_iflag & VI_DOOMED) { 2164 vdestroy(vp); 2165 return; 2166 } else 2167 vfree(vp); 2168 } 2169 VI_UNLOCK(vp); 2170 } 2171 2172 /* 2173 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2174 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2175 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2176 * failed lock upgrade. 2177 */ 2178 static void 2179 vinactive(struct vnode *vp, struct thread *td) 2180 { 2181 2182 ASSERT_VOP_LOCKED(vp, "vinactive"); 2183 ASSERT_VI_LOCKED(vp, "vinactive"); 2184 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2185 ("vinactive: recursed on VI_DOINGINACT")); 2186 vp->v_iflag |= VI_DOINGINACT; 2187 vp->v_iflag &= ~VI_OWEINACT; 2188 VI_UNLOCK(vp); 2189 VOP_INACTIVE(vp, td); 2190 VI_LOCK(vp); 2191 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2192 ("vinactive: lost VI_DOINGINACT")); 2193 vp->v_iflag &= ~VI_DOINGINACT; 2194 } 2195 2196 /* 2197 * Remove any vnodes in the vnode table belonging to mount point mp. 2198 * 2199 * If FORCECLOSE is not specified, there should not be any active ones, 2200 * return error if any are found (nb: this is a user error, not a 2201 * system error). If FORCECLOSE is specified, detach any active vnodes 2202 * that are found. 2203 * 2204 * If WRITECLOSE is set, only flush out regular file vnodes open for 2205 * writing. 2206 * 2207 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2208 * 2209 * `rootrefs' specifies the base reference count for the root vnode 2210 * of this filesystem. The root vnode is considered busy if its 2211 * v_usecount exceeds this value. On a successful return, vflush(, td) 2212 * will call vrele() on the root vnode exactly rootrefs times. 2213 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2214 * be zero. 2215 */ 2216 #ifdef DIAGNOSTIC 2217 static int busyprt = 0; /* print out busy vnodes */ 2218 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2219 #endif 2220 2221 int 2222 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td) 2223 { 2224 struct vnode *vp, *mvp, *rootvp = NULL; 2225 struct vattr vattr; 2226 int busy = 0, error; 2227 2228 CTR1(KTR_VFS, "vflush: mp %p", mp); 2229 if (rootrefs > 0) { 2230 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2231 ("vflush: bad args")); 2232 /* 2233 * Get the filesystem root vnode. We can vput() it 2234 * immediately, since with rootrefs > 0, it won't go away. 2235 */ 2236 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0) 2237 return (error); 2238 vput(rootvp); 2239 2240 } 2241 MNT_ILOCK(mp); 2242 loop: 2243 MNT_VNODE_FOREACH(vp, mp, mvp) { 2244 2245 VI_LOCK(vp); 2246 vholdl(vp); 2247 MNT_IUNLOCK(mp); 2248 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); 2249 if (error) { 2250 vdrop(vp); 2251 MNT_ILOCK(mp); 2252 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 2253 goto loop; 2254 } 2255 /* 2256 * Skip over a vnodes marked VV_SYSTEM. 2257 */ 2258 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2259 VOP_UNLOCK(vp, 0, td); 2260 vdrop(vp); 2261 MNT_ILOCK(mp); 2262 continue; 2263 } 2264 /* 2265 * If WRITECLOSE is set, flush out unlinked but still open 2266 * files (even if open only for reading) and regular file 2267 * vnodes open for writing. 2268 */ 2269 if (flags & WRITECLOSE) { 2270 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); 2271 VI_LOCK(vp); 2272 2273 if ((vp->v_type == VNON || 2274 (error == 0 && vattr.va_nlink > 0)) && 2275 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2276 VOP_UNLOCK(vp, 0, td); 2277 vdropl(vp); 2278 MNT_ILOCK(mp); 2279 continue; 2280 } 2281 } else 2282 VI_LOCK(vp); 2283 /* 2284 * With v_usecount == 0, all we need to do is clear out the 2285 * vnode data structures and we are done. 2286 * 2287 * If FORCECLOSE is set, forcibly close the vnode. 2288 */ 2289 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2290 VNASSERT(vp->v_usecount == 0 || 2291 (vp->v_type != VCHR && vp->v_type != VBLK), vp, 2292 ("device VNODE %p is FORCECLOSED", vp)); 2293 vgonel(vp); 2294 } else { 2295 busy++; 2296 #ifdef DIAGNOSTIC 2297 if (busyprt) 2298 vprint("vflush: busy vnode", vp); 2299 #endif 2300 } 2301 VOP_UNLOCK(vp, 0, td); 2302 vdropl(vp); 2303 MNT_ILOCK(mp); 2304 } 2305 MNT_IUNLOCK(mp); 2306 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2307 /* 2308 * If just the root vnode is busy, and if its refcount 2309 * is equal to `rootrefs', then go ahead and kill it. 2310 */ 2311 VI_LOCK(rootvp); 2312 KASSERT(busy > 0, ("vflush: not busy")); 2313 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2314 ("vflush: usecount %d < rootrefs %d", 2315 rootvp->v_usecount, rootrefs)); 2316 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2317 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td); 2318 vgone(rootvp); 2319 VOP_UNLOCK(rootvp, 0, td); 2320 busy = 0; 2321 } else 2322 VI_UNLOCK(rootvp); 2323 } 2324 if (busy) 2325 return (EBUSY); 2326 for (; rootrefs > 0; rootrefs--) 2327 vrele(rootvp); 2328 return (0); 2329 } 2330 2331 /* 2332 * Recycle an unused vnode to the front of the free list. 2333 */ 2334 int 2335 vrecycle(struct vnode *vp, struct thread *td) 2336 { 2337 int recycled; 2338 2339 ASSERT_VOP_LOCKED(vp, "vrecycle"); 2340 recycled = 0; 2341 VI_LOCK(vp); 2342 if (vp->v_usecount == 0) { 2343 recycled = 1; 2344 vgonel(vp); 2345 } 2346 VI_UNLOCK(vp); 2347 return (recycled); 2348 } 2349 2350 /* 2351 * Eliminate all activity associated with a vnode 2352 * in preparation for reuse. 2353 */ 2354 void 2355 vgone(struct vnode *vp) 2356 { 2357 VI_LOCK(vp); 2358 vgonel(vp); 2359 VI_UNLOCK(vp); 2360 } 2361 2362 /* 2363 * vgone, with the vp interlock held. 2364 */ 2365 void 2366 vgonel(struct vnode *vp) 2367 { 2368 struct thread *td; 2369 int oweinact; 2370 int active; 2371 2372 CTR1(KTR_VFS, "vgonel: vp %p", vp); 2373 ASSERT_VOP_LOCKED(vp, "vgonel"); 2374 ASSERT_VI_LOCKED(vp, "vgonel"); 2375 #if 0 2376 /* XXX Need to fix ttyvp before I enable this. */ 2377 VNASSERT(vp->v_holdcnt, vp, 2378 ("vgonel: vp %p has no reference.", vp)); 2379 #endif 2380 td = curthread; 2381 2382 /* 2383 * Don't vgonel if we're already doomed. 2384 */ 2385 if (vp->v_iflag & VI_DOOMED) 2386 return; 2387 vp->v_iflag |= VI_DOOMED; 2388 /* 2389 * Check to see if the vnode is in use. If so, we have to call 2390 * VOP_CLOSE() and VOP_INACTIVE(). 2391 */ 2392 active = vp->v_usecount; 2393 oweinact = (vp->v_iflag & VI_OWEINACT); 2394 VI_UNLOCK(vp); 2395 /* 2396 * Clean out any buffers associated with the vnode. 2397 * If the flush fails, just toss the buffers. 2398 */ 2399 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 2400 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2401 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0) 2402 vinvalbuf(vp, 0, td, 0, 0); 2403 2404 /* 2405 * If purging an active vnode, it must be closed and 2406 * deactivated before being reclaimed. 2407 */ 2408 if (active) 2409 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2410 if (oweinact || active) { 2411 VI_LOCK(vp); 2412 if ((vp->v_iflag & VI_DOINGINACT) == 0) 2413 vinactive(vp, td); 2414 VI_UNLOCK(vp); 2415 } 2416 /* 2417 * Reclaim the vnode. 2418 */ 2419 if (VOP_RECLAIM(vp, td)) 2420 panic("vgone: cannot reclaim"); 2421 VNASSERT(vp->v_object == NULL, vp, 2422 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 2423 /* 2424 * Delete from old mount point vnode list. 2425 */ 2426 delmntque(vp); 2427 cache_purge(vp); 2428 /* 2429 * Done with purge, reset to the standard lock and invalidate 2430 * the vnode. 2431 */ 2432 VI_LOCK(vp); 2433 vp->v_vnlock = &vp->v_lock; 2434 vp->v_op = &dead_vnodeops; 2435 vp->v_tag = "none"; 2436 vp->v_type = VBAD; 2437 } 2438 2439 /* 2440 * Calculate the total number of references to a special device. 2441 */ 2442 int 2443 vcount(struct vnode *vp) 2444 { 2445 int count; 2446 2447 dev_lock(); 2448 count = vp->v_rdev->si_usecount; 2449 dev_unlock(); 2450 return (count); 2451 } 2452 2453 /* 2454 * Same as above, but using the struct cdev *as argument 2455 */ 2456 int 2457 count_dev(struct cdev *dev) 2458 { 2459 int count; 2460 2461 dev_lock(); 2462 count = dev->si_usecount; 2463 dev_unlock(); 2464 return(count); 2465 } 2466 2467 /* 2468 * Print out a description of a vnode. 2469 */ 2470 static char *typename[] = 2471 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 2472 "VMARKER"}; 2473 2474 void 2475 vn_printf(struct vnode *vp, const char *fmt, ...) 2476 { 2477 va_list ap; 2478 char buf[96]; 2479 2480 va_start(ap, fmt); 2481 vprintf(fmt, ap); 2482 va_end(ap); 2483 printf("%p: ", (void *)vp); 2484 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 2485 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 2486 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 2487 buf[0] = '\0'; 2488 buf[1] = '\0'; 2489 if (vp->v_vflag & VV_ROOT) 2490 strcat(buf, "|VV_ROOT"); 2491 if (vp->v_vflag & VV_TEXT) 2492 strcat(buf, "|VV_TEXT"); 2493 if (vp->v_vflag & VV_SYSTEM) 2494 strcat(buf, "|VV_SYSTEM"); 2495 if (vp->v_iflag & VI_DOOMED) 2496 strcat(buf, "|VI_DOOMED"); 2497 if (vp->v_iflag & VI_FREE) 2498 strcat(buf, "|VI_FREE"); 2499 printf(" flags (%s)\n", buf + 1); 2500 if (mtx_owned(VI_MTX(vp))) 2501 printf(" VI_LOCKed"); 2502 if (vp->v_object != NULL) 2503 printf(" v_object %p ref %d pages %d\n", 2504 vp->v_object, vp->v_object->ref_count, 2505 vp->v_object->resident_page_count); 2506 printf(" "); 2507 lockmgr_printinfo(vp->v_vnlock); 2508 printf("\n"); 2509 if (vp->v_data != NULL) 2510 VOP_PRINT(vp); 2511 } 2512 2513 #ifdef DDB 2514 #include <ddb/ddb.h> 2515 /* 2516 * List all of the locked vnodes in the system. 2517 * Called when debugging the kernel. 2518 */ 2519 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2520 { 2521 struct mount *mp, *nmp; 2522 struct vnode *vp; 2523 2524 /* 2525 * Note: because this is DDB, we can't obey the locking semantics 2526 * for these structures, which means we could catch an inconsistent 2527 * state and dereference a nasty pointer. Not much to be done 2528 * about that. 2529 */ 2530 printf("Locked vnodes\n"); 2531 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2532 nmp = TAILQ_NEXT(mp, mnt_list); 2533 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2534 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL)) 2535 vprint("", vp); 2536 } 2537 nmp = TAILQ_NEXT(mp, mnt_list); 2538 } 2539 } 2540 #endif 2541 2542 /* 2543 * Fill in a struct xvfsconf based on a struct vfsconf. 2544 */ 2545 static void 2546 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2547 { 2548 2549 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2550 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2551 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2552 xvfsp->vfc_flags = vfsp->vfc_flags; 2553 /* 2554 * These are unused in userland, we keep them 2555 * to not break binary compatibility. 2556 */ 2557 xvfsp->vfc_vfsops = NULL; 2558 xvfsp->vfc_next = NULL; 2559 } 2560 2561 /* 2562 * Top level filesystem related information gathering. 2563 */ 2564 static int 2565 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2566 { 2567 struct vfsconf *vfsp; 2568 struct xvfsconf xvfsp; 2569 int error; 2570 2571 error = 0; 2572 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2573 bzero(&xvfsp, sizeof(xvfsp)); 2574 vfsconf2x(vfsp, &xvfsp); 2575 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 2576 if (error) 2577 break; 2578 } 2579 return (error); 2580 } 2581 2582 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2583 "S,xvfsconf", "List of all configured filesystems"); 2584 2585 #ifndef BURN_BRIDGES 2586 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2587 2588 static int 2589 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2590 { 2591 int *name = (int *)arg1 - 1; /* XXX */ 2592 u_int namelen = arg2 + 1; /* XXX */ 2593 struct vfsconf *vfsp; 2594 struct xvfsconf xvfsp; 2595 2596 printf("WARNING: userland calling deprecated sysctl, " 2597 "please rebuild world\n"); 2598 2599 #if 1 || defined(COMPAT_PRELITE2) 2600 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2601 if (namelen == 1) 2602 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2603 #endif 2604 2605 switch (name[1]) { 2606 case VFS_MAXTYPENUM: 2607 if (namelen != 2) 2608 return (ENOTDIR); 2609 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2610 case VFS_CONF: 2611 if (namelen != 3) 2612 return (ENOTDIR); /* overloaded */ 2613 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 2614 if (vfsp->vfc_typenum == name[2]) 2615 break; 2616 if (vfsp == NULL) 2617 return (EOPNOTSUPP); 2618 bzero(&xvfsp, sizeof(xvfsp)); 2619 vfsconf2x(vfsp, &xvfsp); 2620 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2621 } 2622 return (EOPNOTSUPP); 2623 } 2624 2625 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 2626 vfs_sysctl, "Generic filesystem"); 2627 2628 #if 1 || defined(COMPAT_PRELITE2) 2629 2630 static int 2631 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2632 { 2633 int error; 2634 struct vfsconf *vfsp; 2635 struct ovfsconf ovfs; 2636 2637 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 2638 bzero(&ovfs, sizeof(ovfs)); 2639 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2640 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2641 ovfs.vfc_index = vfsp->vfc_typenum; 2642 ovfs.vfc_refcount = vfsp->vfc_refcount; 2643 ovfs.vfc_flags = vfsp->vfc_flags; 2644 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2645 if (error) 2646 return error; 2647 } 2648 return 0; 2649 } 2650 2651 #endif /* 1 || COMPAT_PRELITE2 */ 2652 #endif /* !BURN_BRIDGES */ 2653 2654 #define KINFO_VNODESLOP 10 2655 #ifdef notyet 2656 /* 2657 * Dump vnode list (via sysctl). 2658 */ 2659 /* ARGSUSED */ 2660 static int 2661 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2662 { 2663 struct xvnode *xvn; 2664 struct thread *td = req->td; 2665 struct mount *mp; 2666 struct vnode *vp; 2667 int error, len, n; 2668 2669 /* 2670 * Stale numvnodes access is not fatal here. 2671 */ 2672 req->lock = 0; 2673 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2674 if (!req->oldptr) 2675 /* Make an estimate */ 2676 return (SYSCTL_OUT(req, 0, len)); 2677 2678 error = sysctl_wire_old_buffer(req, 0); 2679 if (error != 0) 2680 return (error); 2681 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2682 n = 0; 2683 mtx_lock(&mountlist_mtx); 2684 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2685 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2686 continue; 2687 MNT_ILOCK(mp); 2688 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2689 if (n == len) 2690 break; 2691 vref(vp); 2692 xvn[n].xv_size = sizeof *xvn; 2693 xvn[n].xv_vnode = vp; 2694 xvn[n].xv_id = 0; /* XXX compat */ 2695 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2696 XV_COPY(usecount); 2697 XV_COPY(writecount); 2698 XV_COPY(holdcnt); 2699 XV_COPY(mount); 2700 XV_COPY(numoutput); 2701 XV_COPY(type); 2702 #undef XV_COPY 2703 xvn[n].xv_flag = vp->v_vflag; 2704 2705 switch (vp->v_type) { 2706 case VREG: 2707 case VDIR: 2708 case VLNK: 2709 break; 2710 case VBLK: 2711 case VCHR: 2712 if (vp->v_rdev == NULL) { 2713 vrele(vp); 2714 continue; 2715 } 2716 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2717 break; 2718 case VSOCK: 2719 xvn[n].xv_socket = vp->v_socket; 2720 break; 2721 case VFIFO: 2722 xvn[n].xv_fifo = vp->v_fifoinfo; 2723 break; 2724 case VNON: 2725 case VBAD: 2726 default: 2727 /* shouldn't happen? */ 2728 vrele(vp); 2729 continue; 2730 } 2731 vrele(vp); 2732 ++n; 2733 } 2734 MNT_IUNLOCK(mp); 2735 mtx_lock(&mountlist_mtx); 2736 vfs_unbusy(mp, td); 2737 if (n == len) 2738 break; 2739 } 2740 mtx_unlock(&mountlist_mtx); 2741 2742 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2743 free(xvn, M_TEMP); 2744 return (error); 2745 } 2746 2747 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2748 0, 0, sysctl_vnode, "S,xvnode", ""); 2749 #endif 2750 2751 /* 2752 * Unmount all filesystems. The list is traversed in reverse order 2753 * of mounting to avoid dependencies. 2754 */ 2755 void 2756 vfs_unmountall(void) 2757 { 2758 struct mount *mp; 2759 struct thread *td; 2760 int error; 2761 2762 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); 2763 td = curthread; 2764 /* 2765 * Since this only runs when rebooting, it is not interlocked. 2766 */ 2767 while(!TAILQ_EMPTY(&mountlist)) { 2768 mp = TAILQ_LAST(&mountlist, mntlist); 2769 error = dounmount(mp, MNT_FORCE, td); 2770 if (error) { 2771 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2772 /* 2773 * XXX: Due to the way in which we mount the root 2774 * file system off of devfs, devfs will generate a 2775 * "busy" warning when we try to unmount it before 2776 * the root. Don't print a warning as a result in 2777 * order to avoid false positive errors that may 2778 * cause needless upset. 2779 */ 2780 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 2781 printf("unmount of %s failed (", 2782 mp->mnt_stat.f_mntonname); 2783 if (error == EBUSY) 2784 printf("BUSY)\n"); 2785 else 2786 printf("%d)\n", error); 2787 } 2788 } else { 2789 /* The unmount has removed mp from the mountlist */ 2790 } 2791 } 2792 } 2793 2794 /* 2795 * perform msync on all vnodes under a mount point 2796 * the mount point must be locked. 2797 */ 2798 void 2799 vfs_msync(struct mount *mp, int flags) 2800 { 2801 struct vnode *vp, *mvp; 2802 struct vm_object *obj; 2803 2804 (void) vn_start_write(NULL, &mp, V_WAIT); 2805 MNT_ILOCK(mp); 2806 MNT_VNODE_FOREACH(vp, mp, mvp) { 2807 VI_LOCK(vp); 2808 if ((vp->v_iflag & VI_OBJDIRTY) && 2809 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2810 MNT_IUNLOCK(mp); 2811 if (!vget(vp, 2812 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 2813 curthread)) { 2814 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 2815 vput(vp); 2816 MNT_ILOCK(mp); 2817 continue; 2818 } 2819 2820 obj = vp->v_object; 2821 if (obj != NULL) { 2822 VM_OBJECT_LOCK(obj); 2823 vm_object_page_clean(obj, 0, 0, 2824 flags == MNT_WAIT ? 2825 OBJPC_SYNC : OBJPC_NOSYNC); 2826 VM_OBJECT_UNLOCK(obj); 2827 } 2828 vput(vp); 2829 } 2830 MNT_ILOCK(mp); 2831 } else 2832 VI_UNLOCK(vp); 2833 } 2834 MNT_IUNLOCK(mp); 2835 vn_finished_write(mp); 2836 } 2837 2838 /* 2839 * Mark a vnode as free, putting it up for recycling. 2840 */ 2841 static void 2842 vfree(struct vnode *vp) 2843 { 2844 2845 CTR1(KTR_VFS, "vfree vp %p", vp); 2846 ASSERT_VI_LOCKED(vp, "vfree"); 2847 mtx_lock(&vnode_free_list_mtx); 2848 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); 2849 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); 2850 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); 2851 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, 2852 ("vfree: Freeing doomed vnode")); 2853 if (vp->v_iflag & VI_AGE) { 2854 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2855 } else { 2856 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 2857 } 2858 freevnodes++; 2859 vp->v_iflag &= ~VI_AGE; 2860 vp->v_iflag |= VI_FREE; 2861 mtx_unlock(&vnode_free_list_mtx); 2862 } 2863 2864 /* 2865 * Opposite of vfree() - mark a vnode as in use. 2866 */ 2867 static void 2868 vbusy(struct vnode *vp) 2869 { 2870 CTR1(KTR_VFS, "vbusy vp %p", vp); 2871 ASSERT_VI_LOCKED(vp, "vbusy"); 2872 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); 2873 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); 2874 2875 mtx_lock(&vnode_free_list_mtx); 2876 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2877 freevnodes--; 2878 vp->v_iflag &= ~(VI_FREE|VI_AGE); 2879 mtx_unlock(&vnode_free_list_mtx); 2880 } 2881 2882 /* 2883 * Initalize per-vnode helper structure to hold poll-related state. 2884 */ 2885 void 2886 v_addpollinfo(struct vnode *vp) 2887 { 2888 struct vpollinfo *vi; 2889 2890 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 2891 if (vp->v_pollinfo != NULL) { 2892 uma_zfree(vnodepoll_zone, vi); 2893 return; 2894 } 2895 vp->v_pollinfo = vi; 2896 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 2897 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock, 2898 vfs_knlunlock, vfs_knllocked); 2899 } 2900 2901 /* 2902 * Record a process's interest in events which might happen to 2903 * a vnode. Because poll uses the historic select-style interface 2904 * internally, this routine serves as both the ``check for any 2905 * pending events'' and the ``record my interest in future events'' 2906 * functions. (These are done together, while the lock is held, 2907 * to avoid race conditions.) 2908 */ 2909 int 2910 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 2911 { 2912 2913 if (vp->v_pollinfo == NULL) 2914 v_addpollinfo(vp); 2915 mtx_lock(&vp->v_pollinfo->vpi_lock); 2916 if (vp->v_pollinfo->vpi_revents & events) { 2917 /* 2918 * This leaves events we are not interested 2919 * in available for the other process which 2920 * which presumably had requested them 2921 * (otherwise they would never have been 2922 * recorded). 2923 */ 2924 events &= vp->v_pollinfo->vpi_revents; 2925 vp->v_pollinfo->vpi_revents &= ~events; 2926 2927 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2928 return events; 2929 } 2930 vp->v_pollinfo->vpi_events |= events; 2931 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 2932 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2933 return 0; 2934 } 2935 2936 /* 2937 * Routine to create and manage a filesystem syncer vnode. 2938 */ 2939 #define sync_close ((int (*)(struct vop_close_args *))nullop) 2940 static int sync_fsync(struct vop_fsync_args *); 2941 static int sync_inactive(struct vop_inactive_args *); 2942 static int sync_reclaim(struct vop_reclaim_args *); 2943 2944 static struct vop_vector sync_vnodeops = { 2945 .vop_bypass = VOP_EOPNOTSUPP, 2946 .vop_close = sync_close, /* close */ 2947 .vop_fsync = sync_fsync, /* fsync */ 2948 .vop_inactive = sync_inactive, /* inactive */ 2949 .vop_reclaim = sync_reclaim, /* reclaim */ 2950 .vop_lock = vop_stdlock, /* lock */ 2951 .vop_unlock = vop_stdunlock, /* unlock */ 2952 .vop_islocked = vop_stdislocked, /* islocked */ 2953 }; 2954 2955 /* 2956 * Create a new filesystem syncer vnode for the specified mount point. 2957 */ 2958 int 2959 vfs_allocate_syncvnode(struct mount *mp) 2960 { 2961 struct vnode *vp; 2962 static long start, incr, next; 2963 int error; 2964 2965 /* Allocate a new vnode */ 2966 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) { 2967 mp->mnt_syncer = NULL; 2968 return (error); 2969 } 2970 vp->v_type = VNON; 2971 /* 2972 * Place the vnode onto the syncer worklist. We attempt to 2973 * scatter them about on the list so that they will go off 2974 * at evenly distributed times even if all the filesystems 2975 * are mounted at once. 2976 */ 2977 next += incr; 2978 if (next == 0 || next > syncer_maxdelay) { 2979 start /= 2; 2980 incr /= 2; 2981 if (start == 0) { 2982 start = syncer_maxdelay / 2; 2983 incr = syncer_maxdelay; 2984 } 2985 next = start; 2986 } 2987 VI_LOCK(vp); 2988 vn_syncer_add_to_worklist(&vp->v_bufobj, 2989 syncdelay > 0 ? next % syncdelay : 0); 2990 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 2991 mtx_lock(&sync_mtx); 2992 sync_vnode_count++; 2993 mtx_unlock(&sync_mtx); 2994 VI_UNLOCK(vp); 2995 mp->mnt_syncer = vp; 2996 return (0); 2997 } 2998 2999 /* 3000 * Do a lazy sync of the filesystem. 3001 */ 3002 static int 3003 sync_fsync(struct vop_fsync_args *ap) 3004 { 3005 struct vnode *syncvp = ap->a_vp; 3006 struct mount *mp = syncvp->v_mount; 3007 struct thread *td = ap->a_td; 3008 int error, asyncflag; 3009 struct bufobj *bo; 3010 3011 /* 3012 * We only need to do something if this is a lazy evaluation. 3013 */ 3014 if (ap->a_waitfor != MNT_LAZY) 3015 return (0); 3016 3017 /* 3018 * Move ourselves to the back of the sync list. 3019 */ 3020 bo = &syncvp->v_bufobj; 3021 BO_LOCK(bo); 3022 vn_syncer_add_to_worklist(bo, syncdelay); 3023 BO_UNLOCK(bo); 3024 3025 /* 3026 * Walk the list of vnodes pushing all that are dirty and 3027 * not already on the sync list. 3028 */ 3029 mtx_lock(&mountlist_mtx); 3030 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3031 mtx_unlock(&mountlist_mtx); 3032 return (0); 3033 } 3034 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3035 vfs_unbusy(mp, td); 3036 return (0); 3037 } 3038 asyncflag = mp->mnt_flag & MNT_ASYNC; 3039 mp->mnt_flag &= ~MNT_ASYNC; 3040 vfs_msync(mp, MNT_NOWAIT); 3041 error = VFS_SYNC(mp, MNT_LAZY, td); 3042 if (asyncflag) 3043 mp->mnt_flag |= MNT_ASYNC; 3044 vn_finished_write(mp); 3045 vfs_unbusy(mp, td); 3046 return (error); 3047 } 3048 3049 /* 3050 * The syncer vnode is no referenced. 3051 */ 3052 static int 3053 sync_inactive(struct vop_inactive_args *ap) 3054 { 3055 3056 vgone(ap->a_vp); 3057 return (0); 3058 } 3059 3060 /* 3061 * The syncer vnode is no longer needed and is being decommissioned. 3062 * 3063 * Modifications to the worklist must be protected by sync_mtx. 3064 */ 3065 static int 3066 sync_reclaim(struct vop_reclaim_args *ap) 3067 { 3068 struct vnode *vp = ap->a_vp; 3069 struct bufobj *bo; 3070 3071 VI_LOCK(vp); 3072 bo = &vp->v_bufobj; 3073 vp->v_mount->mnt_syncer = NULL; 3074 if (bo->bo_flag & BO_ONWORKLST) { 3075 mtx_lock(&sync_mtx); 3076 LIST_REMOVE(bo, bo_synclist); 3077 syncer_worklist_len--; 3078 sync_vnode_count--; 3079 mtx_unlock(&sync_mtx); 3080 bo->bo_flag &= ~BO_ONWORKLST; 3081 } 3082 VI_UNLOCK(vp); 3083 3084 return (0); 3085 } 3086 3087 /* 3088 * Check if vnode represents a disk device 3089 */ 3090 int 3091 vn_isdisk(struct vnode *vp, int *errp) 3092 { 3093 int error; 3094 3095 error = 0; 3096 dev_lock(); 3097 if (vp->v_type != VCHR) 3098 error = ENOTBLK; 3099 else if (vp->v_rdev == NULL) 3100 error = ENXIO; 3101 else if (vp->v_rdev->si_devsw == NULL) 3102 error = ENXIO; 3103 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3104 error = ENOTBLK; 3105 dev_unlock(); 3106 if (errp != NULL) 3107 *errp = error; 3108 return (error == 0); 3109 } 3110 3111 /* 3112 * Common filesystem object access control check routine. Accepts a 3113 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3114 * and optional call-by-reference privused argument allowing vaccess() 3115 * to indicate to the caller whether privilege was used to satisfy the 3116 * request (obsoleted). Returns 0 on success, or an errno on failure. 3117 */ 3118 int 3119 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 3120 mode_t acc_mode, struct ucred *cred, int *privused) 3121 { 3122 mode_t dac_granted; 3123 #ifdef CAPABILITIES 3124 mode_t cap_granted; 3125 #endif 3126 3127 /* 3128 * Look for a normal, non-privileged way to access the file/directory 3129 * as requested. If it exists, go with that. 3130 */ 3131 3132 if (privused != NULL) 3133 *privused = 0; 3134 3135 dac_granted = 0; 3136 3137 /* Check the owner. */ 3138 if (cred->cr_uid == file_uid) { 3139 dac_granted |= VADMIN; 3140 if (file_mode & S_IXUSR) 3141 dac_granted |= VEXEC; 3142 if (file_mode & S_IRUSR) 3143 dac_granted |= VREAD; 3144 if (file_mode & S_IWUSR) 3145 dac_granted |= (VWRITE | VAPPEND); 3146 3147 if ((acc_mode & dac_granted) == acc_mode) 3148 return (0); 3149 3150 goto privcheck; 3151 } 3152 3153 /* Otherwise, check the groups (first match) */ 3154 if (groupmember(file_gid, cred)) { 3155 if (file_mode & S_IXGRP) 3156 dac_granted |= VEXEC; 3157 if (file_mode & S_IRGRP) 3158 dac_granted |= VREAD; 3159 if (file_mode & S_IWGRP) 3160 dac_granted |= (VWRITE | VAPPEND); 3161 3162 if ((acc_mode & dac_granted) == acc_mode) 3163 return (0); 3164 3165 goto privcheck; 3166 } 3167 3168 /* Otherwise, check everyone else. */ 3169 if (file_mode & S_IXOTH) 3170 dac_granted |= VEXEC; 3171 if (file_mode & S_IROTH) 3172 dac_granted |= VREAD; 3173 if (file_mode & S_IWOTH) 3174 dac_granted |= (VWRITE | VAPPEND); 3175 if ((acc_mode & dac_granted) == acc_mode) 3176 return (0); 3177 3178 privcheck: 3179 if (!suser_cred(cred, SUSER_ALLOWJAIL)) { 3180 /* XXX audit: privilege used */ 3181 if (privused != NULL) 3182 *privused = 1; 3183 return (0); 3184 } 3185 3186 #ifdef CAPABILITIES 3187 /* 3188 * Build a capability mask to determine if the set of capabilities 3189 * satisfies the requirements when combined with the granted mask 3190 * from above. 3191 * For each capability, if the capability is required, bitwise 3192 * or the request type onto the cap_granted mask. 3193 */ 3194 cap_granted = 0; 3195 3196 if (type == VDIR) { 3197 /* 3198 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3199 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3200 */ 3201 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3202 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3203 cap_granted |= VEXEC; 3204 } else { 3205 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3206 !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL)) 3207 cap_granted |= VEXEC; 3208 } 3209 3210 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3211 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) 3212 cap_granted |= VREAD; 3213 3214 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3215 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL)) 3216 cap_granted |= (VWRITE | VAPPEND); 3217 3218 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3219 !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL)) 3220 cap_granted |= VADMIN; 3221 3222 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3223 /* XXX audit: privilege used */ 3224 if (privused != NULL) 3225 *privused = 1; 3226 return (0); 3227 } 3228 #endif 3229 3230 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3231 } 3232 3233 /* 3234 * Credential check based on process requesting service, and per-attribute 3235 * permissions. 3236 */ 3237 int 3238 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 3239 struct thread *td, int access) 3240 { 3241 3242 /* 3243 * Kernel-invoked always succeeds. 3244 */ 3245 if (cred == NOCRED) 3246 return (0); 3247 3248 /* 3249 * Do not allow privileged processes in jail to directly 3250 * manipulate system attributes. 3251 * 3252 * XXX What capability should apply here? 3253 * Probably CAP_SYS_SETFFLAG. 3254 */ 3255 switch (attrnamespace) { 3256 case EXTATTR_NAMESPACE_SYSTEM: 3257 /* Potentially should be: return (EPERM); */ 3258 return (suser_cred(cred, 0)); 3259 case EXTATTR_NAMESPACE_USER: 3260 return (VOP_ACCESS(vp, access, cred, td)); 3261 default: 3262 return (EPERM); 3263 } 3264 } 3265 3266 #ifdef DEBUG_VFS_LOCKS 3267 /* 3268 * This only exists to supress warnings from unlocked specfs accesses. It is 3269 * no longer ok to have an unlocked VFS. 3270 */ 3271 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) 3272 3273 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3274 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); 3275 3276 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3277 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); 3278 3279 int vfs_badlock_print = 1; /* Print lock violations. */ 3280 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); 3281 3282 #ifdef KDB 3283 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3284 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); 3285 #endif 3286 3287 static void 3288 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3289 { 3290 3291 #ifdef KDB 3292 if (vfs_badlock_backtrace) 3293 kdb_backtrace(); 3294 #endif 3295 if (vfs_badlock_print) 3296 printf("%s: %p %s\n", str, (void *)vp, msg); 3297 if (vfs_badlock_ddb) 3298 kdb_enter("lock violation"); 3299 } 3300 3301 void 3302 assert_vi_locked(struct vnode *vp, const char *str) 3303 { 3304 3305 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3306 vfs_badlock("interlock is not locked but should be", str, vp); 3307 } 3308 3309 void 3310 assert_vi_unlocked(struct vnode *vp, const char *str) 3311 { 3312 3313 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3314 vfs_badlock("interlock is locked but should not be", str, vp); 3315 } 3316 3317 void 3318 assert_vop_locked(struct vnode *vp, const char *str) 3319 { 3320 3321 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 3322 vfs_badlock("is not locked but should be", str, vp); 3323 } 3324 3325 void 3326 assert_vop_unlocked(struct vnode *vp, const char *str) 3327 { 3328 3329 if (vp && !IGNORE_LOCK(vp) && 3330 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) 3331 vfs_badlock("is locked but should not be", str, vp); 3332 } 3333 3334 void 3335 assert_vop_elocked(struct vnode *vp, const char *str) 3336 { 3337 3338 if (vp && !IGNORE_LOCK(vp) && 3339 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) 3340 vfs_badlock("is not exclusive locked but should be", str, vp); 3341 } 3342 3343 #if 0 3344 void 3345 assert_vop_elocked_other(struct vnode *vp, const char *str) 3346 { 3347 3348 if (vp && !IGNORE_LOCK(vp) && 3349 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) 3350 vfs_badlock("is not exclusive locked by another thread", 3351 str, vp); 3352 } 3353 3354 void 3355 assert_vop_slocked(struct vnode *vp, const char *str) 3356 { 3357 3358 if (vp && !IGNORE_LOCK(vp) && 3359 VOP_ISLOCKED(vp, curthread) != LK_SHARED) 3360 vfs_badlock("is not locked shared but should be", str, vp); 3361 } 3362 #endif /* 0 */ 3363 #endif /* DEBUG_VFS_LOCKS */ 3364 3365 void 3366 vop_rename_pre(void *ap) 3367 { 3368 struct vop_rename_args *a = ap; 3369 3370 #ifdef DEBUG_VFS_LOCKS 3371 if (a->a_tvp) 3372 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3373 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3374 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3375 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3376 3377 /* Check the source (from). */ 3378 if (a->a_tdvp != a->a_fdvp) 3379 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3380 if (a->a_tvp != a->a_fvp) 3381 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); 3382 3383 /* Check the target. */ 3384 if (a->a_tvp) 3385 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3386 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3387 #endif 3388 if (a->a_tdvp != a->a_fdvp) 3389 vhold(a->a_fdvp); 3390 if (a->a_tvp != a->a_fvp) 3391 vhold(a->a_fvp); 3392 vhold(a->a_tdvp); 3393 if (a->a_tvp) 3394 vhold(a->a_tvp); 3395 } 3396 3397 void 3398 vop_strategy_pre(void *ap) 3399 { 3400 #ifdef DEBUG_VFS_LOCKS 3401 struct vop_strategy_args *a; 3402 struct buf *bp; 3403 3404 a = ap; 3405 bp = a->a_bp; 3406 3407 /* 3408 * Cluster ops lock their component buffers but not the IO container. 3409 */ 3410 if ((bp->b_flags & B_CLUSTER) != 0) 3411 return; 3412 3413 if (BUF_REFCNT(bp) < 1) { 3414 if (vfs_badlock_print) 3415 printf( 3416 "VOP_STRATEGY: bp is not locked but should be\n"); 3417 if (vfs_badlock_ddb) 3418 kdb_enter("lock violation"); 3419 } 3420 #endif 3421 } 3422 3423 void 3424 vop_lookup_pre(void *ap) 3425 { 3426 #ifdef DEBUG_VFS_LOCKS 3427 struct vop_lookup_args *a; 3428 struct vnode *dvp; 3429 3430 a = ap; 3431 dvp = a->a_dvp; 3432 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3433 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3434 #endif 3435 } 3436 3437 void 3438 vop_lookup_post(void *ap, int rc) 3439 { 3440 #ifdef DEBUG_VFS_LOCKS 3441 struct vop_lookup_args *a; 3442 struct vnode *dvp; 3443 struct vnode *vp; 3444 3445 a = ap; 3446 dvp = a->a_dvp; 3447 vp = *(a->a_vpp); 3448 3449 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3450 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3451 3452 if (!rc) 3453 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); 3454 #endif 3455 } 3456 3457 void 3458 vop_lock_pre(void *ap) 3459 { 3460 #ifdef DEBUG_VFS_LOCKS 3461 struct vop_lock_args *a = ap; 3462 3463 if ((a->a_flags & LK_INTERLOCK) == 0) 3464 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3465 else 3466 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3467 #endif 3468 } 3469 3470 void 3471 vop_lock_post(void *ap, int rc) 3472 { 3473 #ifdef DEBUG_VFS_LOCKS 3474 struct vop_lock_args *a = ap; 3475 3476 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3477 if (rc == 0) 3478 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3479 #endif 3480 } 3481 3482 void 3483 vop_unlock_pre(void *ap) 3484 { 3485 #ifdef DEBUG_VFS_LOCKS 3486 struct vop_unlock_args *a = ap; 3487 3488 if (a->a_flags & LK_INTERLOCK) 3489 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 3490 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 3491 #endif 3492 } 3493 3494 void 3495 vop_unlock_post(void *ap, int rc) 3496 { 3497 #ifdef DEBUG_VFS_LOCKS 3498 struct vop_unlock_args *a = ap; 3499 3500 if (a->a_flags & LK_INTERLOCK) 3501 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 3502 #endif 3503 } 3504 3505 void 3506 vop_create_post(void *ap, int rc) 3507 { 3508 struct vop_create_args *a = ap; 3509 3510 if (!rc) 3511 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3512 } 3513 3514 void 3515 vop_link_post(void *ap, int rc) 3516 { 3517 struct vop_link_args *a = ap; 3518 3519 if (!rc) { 3520 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 3521 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 3522 } 3523 } 3524 3525 void 3526 vop_mkdir_post(void *ap, int rc) 3527 { 3528 struct vop_mkdir_args *a = ap; 3529 3530 if (!rc) 3531 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3532 } 3533 3534 void 3535 vop_mknod_post(void *ap, int rc) 3536 { 3537 struct vop_mknod_args *a = ap; 3538 3539 if (!rc) 3540 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3541 } 3542 3543 void 3544 vop_remove_post(void *ap, int rc) 3545 { 3546 struct vop_remove_args *a = ap; 3547 3548 if (!rc) { 3549 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3550 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3551 } 3552 } 3553 3554 void 3555 vop_rename_post(void *ap, int rc) 3556 { 3557 struct vop_rename_args *a = ap; 3558 3559 if (!rc) { 3560 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 3561 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 3562 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 3563 if (a->a_tvp) 3564 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 3565 } 3566 if (a->a_tdvp != a->a_fdvp) 3567 vdrop(a->a_fdvp); 3568 if (a->a_tvp != a->a_fvp) 3569 vdrop(a->a_fvp); 3570 vdrop(a->a_tdvp); 3571 if (a->a_tvp) 3572 vdrop(a->a_tvp); 3573 } 3574 3575 void 3576 vop_rmdir_post(void *ap, int rc) 3577 { 3578 struct vop_rmdir_args *a = ap; 3579 3580 if (!rc) { 3581 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 3582 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 3583 } 3584 } 3585 3586 void 3587 vop_setattr_post(void *ap, int rc) 3588 { 3589 struct vop_setattr_args *a = ap; 3590 3591 if (!rc) 3592 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 3593 } 3594 3595 void 3596 vop_symlink_post(void *ap, int rc) 3597 { 3598 struct vop_symlink_args *a = ap; 3599 3600 if (!rc) 3601 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 3602 } 3603 3604 static struct knlist fs_knlist; 3605 3606 static void 3607 vfs_event_init(void *arg) 3608 { 3609 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL); 3610 } 3611 /* XXX - correct order? */ 3612 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 3613 3614 void 3615 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) 3616 { 3617 3618 KNOTE_UNLOCKED(&fs_knlist, event); 3619 } 3620 3621 static int filt_fsattach(struct knote *kn); 3622 static void filt_fsdetach(struct knote *kn); 3623 static int filt_fsevent(struct knote *kn, long hint); 3624 3625 struct filterops fs_filtops = 3626 { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; 3627 3628 static int 3629 filt_fsattach(struct knote *kn) 3630 { 3631 3632 kn->kn_flags |= EV_CLEAR; 3633 knlist_add(&fs_knlist, kn, 0); 3634 return (0); 3635 } 3636 3637 static void 3638 filt_fsdetach(struct knote *kn) 3639 { 3640 3641 knlist_remove(&fs_knlist, kn, 0); 3642 } 3643 3644 static int 3645 filt_fsevent(struct knote *kn, long hint) 3646 { 3647 3648 kn->kn_fflags |= hint; 3649 return (kn->kn_fflags != 0); 3650 } 3651 3652 static int 3653 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 3654 { 3655 struct vfsidctl vc; 3656 int error; 3657 struct mount *mp; 3658 3659 error = SYSCTL_IN(req, &vc, sizeof(vc)); 3660 if (error) 3661 return (error); 3662 if (vc.vc_vers != VFS_CTL_VERS1) 3663 return (EINVAL); 3664 mp = vfs_getvfs(&vc.vc_fsid); 3665 if (mp == NULL) 3666 return (ENOENT); 3667 /* ensure that a specific sysctl goes to the right filesystem. */ 3668 if (strcmp(vc.vc_fstypename, "*") != 0 && 3669 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 3670 return (EINVAL); 3671 } 3672 VCTLTOREQ(&vc, req); 3673 return (VFS_SYSCTL(mp, vc.vc_op, req)); 3674 } 3675 3676 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, 3677 NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid"); 3678 3679 /* 3680 * Function to initialize a va_filerev field sensibly. 3681 * XXX: Wouldn't a random number make a lot more sense ?? 3682 */ 3683 u_quad_t 3684 init_va_filerev(void) 3685 { 3686 struct bintime bt; 3687 3688 getbinuptime(&bt); 3689 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 3690 } 3691 3692 static int filt_vfsread(struct knote *kn, long hint); 3693 static int filt_vfswrite(struct knote *kn, long hint); 3694 static int filt_vfsvnode(struct knote *kn, long hint); 3695 static void filt_vfsdetach(struct knote *kn); 3696 static struct filterops vfsread_filtops = 3697 { 1, NULL, filt_vfsdetach, filt_vfsread }; 3698 static struct filterops vfswrite_filtops = 3699 { 1, NULL, filt_vfsdetach, filt_vfswrite }; 3700 static struct filterops vfsvnode_filtops = 3701 { 1, NULL, filt_vfsdetach, filt_vfsvnode }; 3702 3703 static void 3704 vfs_knllock(void *arg) 3705 { 3706 struct vnode *vp = arg; 3707 3708 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 3709 } 3710 3711 static void 3712 vfs_knlunlock(void *arg) 3713 { 3714 struct vnode *vp = arg; 3715 3716 VOP_UNLOCK(vp, 0, curthread); 3717 } 3718 3719 static int 3720 vfs_knllocked(void *arg) 3721 { 3722 struct vnode *vp = arg; 3723 3724 return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE); 3725 } 3726 3727 int 3728 vfs_kqfilter(struct vop_kqfilter_args *ap) 3729 { 3730 struct vnode *vp = ap->a_vp; 3731 struct knote *kn = ap->a_kn; 3732 struct knlist *knl; 3733 3734 switch (kn->kn_filter) { 3735 case EVFILT_READ: 3736 kn->kn_fop = &vfsread_filtops; 3737 break; 3738 case EVFILT_WRITE: 3739 kn->kn_fop = &vfswrite_filtops; 3740 break; 3741 case EVFILT_VNODE: 3742 kn->kn_fop = &vfsvnode_filtops; 3743 break; 3744 default: 3745 return (EINVAL); 3746 } 3747 3748 kn->kn_hook = (caddr_t)vp; 3749 3750 if (vp->v_pollinfo == NULL) 3751 v_addpollinfo(vp); 3752 if (vp->v_pollinfo == NULL) 3753 return (ENOMEM); 3754 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 3755 knlist_add(knl, kn, 0); 3756 3757 return (0); 3758 } 3759 3760 /* 3761 * Detach knote from vnode 3762 */ 3763 static void 3764 filt_vfsdetach(struct knote *kn) 3765 { 3766 struct vnode *vp = (struct vnode *)kn->kn_hook; 3767 3768 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 3769 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 3770 } 3771 3772 /*ARGSUSED*/ 3773 static int 3774 filt_vfsread(struct knote *kn, long hint) 3775 { 3776 struct vnode *vp = (struct vnode *)kn->kn_hook; 3777 struct vattr va; 3778 3779 /* 3780 * filesystem is gone, so set the EOF flag and schedule 3781 * the knote for deletion. 3782 */ 3783 if (hint == NOTE_REVOKE) { 3784 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3785 return (1); 3786 } 3787 3788 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread)) 3789 return (0); 3790 3791 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 3792 return (kn->kn_data != 0); 3793 } 3794 3795 /*ARGSUSED*/ 3796 static int 3797 filt_vfswrite(struct knote *kn, long hint) 3798 { 3799 /* 3800 * filesystem is gone, so set the EOF flag and schedule 3801 * the knote for deletion. 3802 */ 3803 if (hint == NOTE_REVOKE) 3804 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 3805 3806 kn->kn_data = 0; 3807 return (1); 3808 } 3809 3810 static int 3811 filt_vfsvnode(struct knote *kn, long hint) 3812 { 3813 if (kn->kn_sfflags & hint) 3814 kn->kn_fflags |= hint; 3815 if (hint == NOTE_REVOKE) { 3816 kn->kn_flags |= EV_EOF; 3817 return (1); 3818 } 3819 return (kn->kn_fflags != 0); 3820 } 3821 3822 int 3823 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 3824 { 3825 int error; 3826 3827 if (dp->d_reclen > ap->a_uio->uio_resid) 3828 return (ENAMETOOLONG); 3829 error = uiomove(dp, dp->d_reclen, ap->a_uio); 3830 if (error) { 3831 if (ap->a_ncookies != NULL) { 3832 if (ap->a_cookies != NULL) 3833 free(ap->a_cookies, M_TEMP); 3834 ap->a_cookies = NULL; 3835 *ap->a_ncookies = 0; 3836 } 3837 return (error); 3838 } 3839 if (ap->a_ncookies == NULL) 3840 return (0); 3841 3842 KASSERT(ap->a_cookies, 3843 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 3844 3845 *ap->a_cookies = realloc(*ap->a_cookies, 3846 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 3847 (*ap->a_cookies)[*ap->a_ncookies] = off; 3848 return (0); 3849 } 3850 3851 /* 3852 * Mark for update the access time of the file if the filesystem 3853 * supports VA_MARK_ATIME. This functionality is used by execve 3854 * and mmap, so we want to avoid the synchronous I/O implied by 3855 * directly setting va_atime for the sake of efficiency. 3856 */ 3857 void 3858 vfs_mark_atime(struct vnode *vp, struct thread *td) 3859 { 3860 struct vattr atimeattr; 3861 3862 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) { 3863 VATTR_NULL(&atimeattr); 3864 atimeattr.va_vaflags |= VA_MARK_ATIME; 3865 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td); 3866 } 3867 } 3868