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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 39 * $FreeBSD$ 40 */ 41 42 /* 43 * External virtual filesystem routines 44 */ 45 #include "opt_ddb.h" 46 #include "opt_ffs.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/bio.h> 51 #include <sys/buf.h> 52 #include <sys/conf.h> 53 #include <sys/eventhandler.h> 54 #include <sys/fcntl.h> 55 #include <sys/kernel.h> 56 #include <sys/kthread.h> 57 #include <sys/malloc.h> 58 #include <sys/mount.h> 59 #include <sys/namei.h> 60 #include <sys/stat.h> 61 #include <sys/sysctl.h> 62 #include <sys/syslog.h> 63 #include <sys/vmmeter.h> 64 #include <sys/vnode.h> 65 66 #include <vm/vm.h> 67 #include <vm/vm_object.h> 68 #include <vm/vm_extern.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_page.h> 72 #include <vm/uma.h> 73 74 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 75 76 static void addalias(struct vnode *vp, dev_t nvp_rdev); 77 static void insmntque(struct vnode *vp, struct mount *mp); 78 static void vclean(struct vnode *vp, int flags, struct thread *td); 79 static void vlruvp(struct vnode *vp); 80 81 /* 82 * Number of vnodes in existence. Increased whenever getnewvnode() 83 * allocates a new vnode, never decreased. 84 */ 85 static unsigned long numvnodes; 86 87 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 88 89 /* 90 * Conversion tables for conversion from vnode types to inode formats 91 * and back. 92 */ 93 enum vtype iftovt_tab[16] = { 94 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 95 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 96 }; 97 int vttoif_tab[9] = { 98 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 99 S_IFSOCK, S_IFIFO, S_IFMT, 100 }; 101 102 /* 103 * List of vnodes that are ready for recycling. 104 */ 105 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 106 107 /* 108 * Minimum number of free vnodes. If there are fewer than this free vnodes, 109 * getnewvnode() will return a newly allocated vnode. 110 */ 111 static u_long wantfreevnodes = 25; 112 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 113 /* Number of vnodes in the free list. */ 114 static u_long freevnodes; 115 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 116 117 /* 118 * Various variables used for debugging the new implementation of 119 * reassignbuf(). 120 * XXX these are probably of (very) limited utility now. 121 */ 122 static int reassignbufcalls; 123 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 124 static int reassignbufloops; 125 SYSCTL_INT(_vfs, OID_AUTO, reassignbufloops, CTLFLAG_RW, &reassignbufloops, 0, ""); 126 static int reassignbufsortgood; 127 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortgood, CTLFLAG_RW, &reassignbufsortgood, 0, ""); 128 static int reassignbufsortbad; 129 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad, 0, ""); 130 /* Set to 0 for old insertion-sort based reassignbuf, 1 for modern method. */ 131 static int reassignbufmethod = 1; 132 SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, ""); 133 static int nameileafonly; 134 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 135 136 #ifdef ENABLE_VFS_IOOPT 137 /* See NOTES for a description of this setting. */ 138 int vfs_ioopt; 139 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, ""); 140 #endif 141 142 /* List of mounted filesystems. */ 143 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 144 145 /* For any iteration/modification of mountlist */ 146 struct mtx mountlist_mtx; 147 148 /* For any iteration/modification of mnt_vnodelist */ 149 struct mtx mntvnode_mtx; 150 151 /* 152 * Cache for the mount type id assigned to NFS. This is used for 153 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 154 */ 155 int nfs_mount_type = -1; 156 157 /* To keep more than one thread at a time from running vfs_getnewfsid */ 158 static struct mtx mntid_mtx; 159 160 /* For any iteration/modification of vnode_free_list */ 161 static struct mtx vnode_free_list_mtx; 162 163 /* 164 * For any iteration/modification of dev->si_hlist (linked through 165 * v_specnext) 166 */ 167 static struct mtx spechash_mtx; 168 169 /* Publicly exported FS */ 170 struct nfs_public nfs_pub; 171 172 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 173 static uma_zone_t vnode_zone; 174 static uma_zone_t vnodepoll_zone; 175 176 /* Set to 1 to print out reclaim of active vnodes */ 177 int prtactive; 178 179 /* 180 * The workitem queue. 181 * 182 * It is useful to delay writes of file data and filesystem metadata 183 * for tens of seconds so that quickly created and deleted files need 184 * not waste disk bandwidth being created and removed. To realize this, 185 * we append vnodes to a "workitem" queue. When running with a soft 186 * updates implementation, most pending metadata dependencies should 187 * not wait for more than a few seconds. Thus, mounted on block devices 188 * are delayed only about a half the time that file data is delayed. 189 * Similarly, directory updates are more critical, so are only delayed 190 * about a third the time that file data is delayed. Thus, there are 191 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 192 * one each second (driven off the filesystem syncer process). The 193 * syncer_delayno variable indicates the next queue that is to be processed. 194 * Items that need to be processed soon are placed in this queue: 195 * 196 * syncer_workitem_pending[syncer_delayno] 197 * 198 * A delay of fifteen seconds is done by placing the request fifteen 199 * entries later in the queue: 200 * 201 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 202 * 203 */ 204 static int syncer_delayno; 205 static long syncer_mask; 206 LIST_HEAD(synclist, vnode); 207 static struct synclist *syncer_workitem_pending; 208 209 #define SYNCER_MAXDELAY 32 210 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 211 static int syncdelay = 30; /* max time to delay syncing data */ 212 static int filedelay = 30; /* time to delay syncing files */ 213 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 214 static int dirdelay = 29; /* time to delay syncing directories */ 215 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 216 static int metadelay = 28; /* time to delay syncing metadata */ 217 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 218 static int rushjob; /* number of slots to run ASAP */ 219 static int stat_rush_requests; /* number of times I/O speeded up */ 220 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 221 222 /* 223 * Number of vnodes we want to exist at any one time. This is mostly used 224 * to size hash tables in vnode-related code. It is normally not used in 225 * getnewvnode(), as wantfreevnodes is normally nonzero.) 226 * 227 * XXX desiredvnodes is historical cruft and should not exist. 228 */ 229 int desiredvnodes; 230 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 231 &desiredvnodes, 0, "Maximum number of vnodes"); 232 static int minvnodes; 233 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 234 &minvnodes, 0, "Minimum number of vnodes"); 235 static int vnlru_nowhere; 236 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, 237 "Number of times the vnlru process ran without success"); 238 239 void 240 v_addpollinfo(struct vnode *vp) 241 { 242 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 243 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 244 } 245 246 /* 247 * Initialize the vnode management data structures. 248 */ 249 static void 250 vntblinit(void *dummy __unused) 251 { 252 253 desiredvnodes = maxproc + cnt.v_page_count / 4; 254 minvnodes = desiredvnodes / 4; 255 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 256 mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); 257 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 258 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 259 TAILQ_INIT(&vnode_free_list); 260 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 261 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 262 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 263 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 264 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 265 /* 266 * Initialize the filesystem syncer. 267 */ 268 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 269 &syncer_mask); 270 syncer_maxdelay = syncer_mask + 1; 271 } 272 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 273 274 275 /* 276 * Mark a mount point as busy. Used to synchronize access and to delay 277 * unmounting. Interlock is not released on failure. 278 */ 279 int 280 vfs_busy(mp, flags, interlkp, td) 281 struct mount *mp; 282 int flags; 283 struct mtx *interlkp; 284 struct thread *td; 285 { 286 int lkflags; 287 288 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 289 if (flags & LK_NOWAIT) 290 return (ENOENT); 291 mp->mnt_kern_flag |= MNTK_MWAIT; 292 /* 293 * Since all busy locks are shared except the exclusive 294 * lock granted when unmounting, the only place that a 295 * wakeup needs to be done is at the release of the 296 * exclusive lock at the end of dounmount. 297 */ 298 msleep((caddr_t)mp, interlkp, PVFS, "vfs_busy", 0); 299 return (ENOENT); 300 } 301 lkflags = LK_SHARED | LK_NOPAUSE; 302 if (interlkp) 303 lkflags |= LK_INTERLOCK; 304 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 305 panic("vfs_busy: unexpected lock failure"); 306 return (0); 307 } 308 309 /* 310 * Free a busy filesystem. 311 */ 312 void 313 vfs_unbusy(mp, td) 314 struct mount *mp; 315 struct thread *td; 316 { 317 318 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 319 } 320 321 /* 322 * Lookup a filesystem type, and if found allocate and initialize 323 * a mount structure for it. 324 * 325 * Devname is usually updated by mount(8) after booting. 326 */ 327 int 328 vfs_rootmountalloc(fstypename, devname, mpp) 329 char *fstypename; 330 char *devname; 331 struct mount **mpp; 332 { 333 struct thread *td = curthread; /* XXX */ 334 struct vfsconf *vfsp; 335 struct mount *mp; 336 337 if (fstypename == NULL) 338 return (ENODEV); 339 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 340 if (!strcmp(vfsp->vfc_name, fstypename)) 341 break; 342 if (vfsp == NULL) 343 return (ENODEV); 344 mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 345 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 346 (void)vfs_busy(mp, LK_NOWAIT, 0, td); 347 TAILQ_INIT(&mp->mnt_nvnodelist); 348 TAILQ_INIT(&mp->mnt_reservedvnlist); 349 mp->mnt_vfc = vfsp; 350 mp->mnt_op = vfsp->vfc_vfsops; 351 mp->mnt_flag = MNT_RDONLY; 352 mp->mnt_vnodecovered = NULLVP; 353 vfsp->vfc_refcount++; 354 mp->mnt_iosize_max = DFLTPHYS; 355 mp->mnt_stat.f_type = vfsp->vfc_typenum; 356 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 357 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 358 mp->mnt_stat.f_mntonname[0] = '/'; 359 mp->mnt_stat.f_mntonname[1] = 0; 360 (void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0); 361 *mpp = mp; 362 return (0); 363 } 364 365 /* 366 * Find an appropriate filesystem to use for the root. If a filesystem 367 * has not been preselected, walk through the list of known filesystems 368 * trying those that have mountroot routines, and try them until one 369 * works or we have tried them all. 370 */ 371 #ifdef notdef /* XXX JH */ 372 int 373 lite2_vfs_mountroot() 374 { 375 struct vfsconf *vfsp; 376 extern int (*lite2_mountroot)(void); 377 int error; 378 379 if (lite2_mountroot != NULL) 380 return ((*lite2_mountroot)()); 381 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 382 if (vfsp->vfc_mountroot == NULL) 383 continue; 384 if ((error = (*vfsp->vfc_mountroot)()) == 0) 385 return (0); 386 printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error); 387 } 388 return (ENODEV); 389 } 390 #endif 391 392 /* 393 * Lookup a mount point by filesystem identifier. 394 */ 395 struct mount * 396 vfs_getvfs(fsid) 397 fsid_t *fsid; 398 { 399 register struct mount *mp; 400 401 mtx_lock(&mountlist_mtx); 402 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 403 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 404 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 405 mtx_unlock(&mountlist_mtx); 406 return (mp); 407 } 408 } 409 mtx_unlock(&mountlist_mtx); 410 return ((struct mount *) 0); 411 } 412 413 /* 414 * Get a new unique fsid. Try to make its val[0] unique, since this value 415 * will be used to create fake device numbers for stat(). Also try (but 416 * not so hard) make its val[0] unique mod 2^16, since some emulators only 417 * support 16-bit device numbers. We end up with unique val[0]'s for the 418 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 419 * 420 * Keep in mind that several mounts may be running in parallel. Starting 421 * the search one past where the previous search terminated is both a 422 * micro-optimization and a defense against returning the same fsid to 423 * different mounts. 424 */ 425 void 426 vfs_getnewfsid(mp) 427 struct mount *mp; 428 { 429 static u_int16_t mntid_base; 430 fsid_t tfsid; 431 int mtype; 432 433 mtx_lock(&mntid_mtx); 434 mtype = mp->mnt_vfc->vfc_typenum; 435 tfsid.val[1] = mtype; 436 mtype = (mtype & 0xFF) << 24; 437 for (;;) { 438 tfsid.val[0] = makeudev(255, 439 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 440 mntid_base++; 441 if (vfs_getvfs(&tfsid) == NULL) 442 break; 443 } 444 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 445 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 446 mtx_unlock(&mntid_mtx); 447 } 448 449 /* 450 * Knob to control the precision of file timestamps: 451 * 452 * 0 = seconds only; nanoseconds zeroed. 453 * 1 = seconds and nanoseconds, accurate within 1/HZ. 454 * 2 = seconds and nanoseconds, truncated to microseconds. 455 * >=3 = seconds and nanoseconds, maximum precision. 456 */ 457 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 458 459 static int timestamp_precision = TSP_SEC; 460 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 461 ×tamp_precision, 0, ""); 462 463 /* 464 * Get a current timestamp. 465 */ 466 void 467 vfs_timestamp(tsp) 468 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 * Get a mount option by its name. 493 * 494 * Return 0 if the option was found, ENOENT otherwise. 495 * If len is non-NULL it will be filled with the length 496 * of the option. If buf is non-NULL, it will be filled 497 * with the address of the option. 498 */ 499 int 500 vfs_getopt(opts, name, buf, len) 501 struct vfsoptlist *opts; 502 const char *name; 503 void **buf; 504 int *len; 505 { 506 struct vfsopt *opt; 507 int i; 508 509 i = 0; 510 opt = opts->opt; 511 while (i++ < opts->optcnt) { 512 if (strcmp(name, opt->name) == 0) { 513 if (len != NULL) 514 *len = opt->len; 515 if (buf != NULL) 516 *buf = opt->value; 517 return (0); 518 } 519 opt++; 520 } 521 return (ENOENT); 522 } 523 524 /* 525 * Find and copy a mount option. 526 * 527 * The size of the buffer has to be specified 528 * in len, if it is not the same length as the 529 * mount option, EINVAL is returned. 530 * Returns ENOENT if the option is not found. 531 */ 532 int 533 vfs_copyopt(opts, name, dest, len) 534 struct vfsoptlist *opts; 535 const char *name; 536 void *dest; 537 int len; 538 { 539 struct vfsopt *opt; 540 int i; 541 542 i = 0; 543 opt = opts->opt; 544 while (i++ < opts->optcnt) { 545 if (strcmp(name, opt->name) == 0) { 546 if (len != opt->len) 547 return (EINVAL); 548 bcopy(opt->value, dest, opt->len); 549 return (0); 550 } 551 opt++; 552 } 553 return (ENOENT); 554 } 555 556 /* 557 * Set vnode attributes to VNOVAL 558 */ 559 void 560 vattr_null(vap) 561 register struct vattr *vap; 562 { 563 564 vap->va_type = VNON; 565 vap->va_size = VNOVAL; 566 vap->va_bytes = VNOVAL; 567 vap->va_mode = VNOVAL; 568 vap->va_nlink = VNOVAL; 569 vap->va_uid = VNOVAL; 570 vap->va_gid = VNOVAL; 571 vap->va_fsid = VNOVAL; 572 vap->va_fileid = VNOVAL; 573 vap->va_blocksize = VNOVAL; 574 vap->va_rdev = VNOVAL; 575 vap->va_atime.tv_sec = VNOVAL; 576 vap->va_atime.tv_nsec = VNOVAL; 577 vap->va_mtime.tv_sec = VNOVAL; 578 vap->va_mtime.tv_nsec = VNOVAL; 579 vap->va_ctime.tv_sec = VNOVAL; 580 vap->va_ctime.tv_nsec = VNOVAL; 581 vap->va_flags = VNOVAL; 582 vap->va_gen = VNOVAL; 583 vap->va_vaflags = 0; 584 } 585 586 /* 587 * This routine is called when we have too many vnodes. It attempts 588 * to free <count> vnodes and will potentially free vnodes that still 589 * have VM backing store (VM backing store is typically the cause 590 * of a vnode blowout so we want to do this). Therefore, this operation 591 * is not considered cheap. 592 * 593 * A number of conditions may prevent a vnode from being reclaimed. 594 * the buffer cache may have references on the vnode, a directory 595 * vnode may still have references due to the namei cache representing 596 * underlying files, or the vnode may be in active use. It is not 597 * desireable to reuse such vnodes. These conditions may cause the 598 * number of vnodes to reach some minimum value regardless of what 599 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 600 */ 601 static int 602 vlrureclaim(struct mount *mp, int count) 603 { 604 struct vnode *vp; 605 int done; 606 int trigger; 607 int usevnodes; 608 609 /* 610 * Calculate the trigger point, don't allow user 611 * screwups to blow us up. This prevents us from 612 * recycling vnodes with lots of resident pages. We 613 * aren't trying to free memory, we are trying to 614 * free vnodes. 615 */ 616 usevnodes = desiredvnodes; 617 if (usevnodes <= 0) 618 usevnodes = 1; 619 trigger = cnt.v_page_count * 2 / usevnodes; 620 621 done = 0; 622 mtx_lock(&mntvnode_mtx); 623 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 624 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 625 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 626 627 if (vp->v_type != VNON && 628 vp->v_type != VBAD && 629 VMIGHTFREE(vp) && /* critical path opt */ 630 (vp->v_object == NULL || vp->v_object->resident_page_count < trigger) && 631 mtx_trylock(&vp->v_interlock) 632 ) { 633 mtx_unlock(&mntvnode_mtx); 634 if (VMIGHTFREE(vp)) { 635 vgonel(vp, curthread); 636 done++; 637 } else { 638 mtx_unlock(&vp->v_interlock); 639 } 640 mtx_lock(&mntvnode_mtx); 641 } 642 --count; 643 } 644 mtx_unlock(&mntvnode_mtx); 645 return done; 646 } 647 648 /* 649 * Attempt to recycle vnodes in a context that is always safe to block. 650 * Calling vlrurecycle() from the bowels of filesystem code has some 651 * interesting deadlock problems. 652 */ 653 static struct proc *vnlruproc; 654 static int vnlruproc_sig; 655 656 static void 657 vnlru_proc(void) 658 { 659 struct mount *mp, *nmp; 660 int s; 661 int done; 662 struct proc *p = vnlruproc; 663 struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 664 665 mtx_lock(&Giant); 666 667 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 668 SHUTDOWN_PRI_FIRST); 669 670 s = splbio(); 671 for (;;) { 672 kthread_suspend_check(p); 673 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 674 vnlruproc_sig = 0; 675 tsleep(vnlruproc, PVFS, "vlruwt", 0); 676 continue; 677 } 678 done = 0; 679 mtx_lock(&mountlist_mtx); 680 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 681 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 682 nmp = TAILQ_NEXT(mp, mnt_list); 683 continue; 684 } 685 done += vlrureclaim(mp, 10); 686 mtx_lock(&mountlist_mtx); 687 nmp = TAILQ_NEXT(mp, mnt_list); 688 vfs_unbusy(mp, td); 689 } 690 mtx_unlock(&mountlist_mtx); 691 if (done == 0) { 692 #if 0 693 /* These messages are temporary debugging aids */ 694 if (vnlru_nowhere < 5) 695 printf("vnlru process getting nowhere..\n"); 696 else if (vnlru_nowhere == 5) 697 printf("vnlru process messages stopped.\n"); 698 #endif 699 vnlru_nowhere++; 700 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 701 } 702 } 703 splx(s); 704 } 705 706 static struct kproc_desc vnlru_kp = { 707 "vnlru", 708 vnlru_proc, 709 &vnlruproc 710 }; 711 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 712 713 714 /* 715 * Routines having to do with the management of the vnode table. 716 */ 717 718 /* 719 * Return the next vnode from the free list. 720 */ 721 int 722 getnewvnode(tag, mp, vops, vpp) 723 enum vtagtype tag; 724 struct mount *mp; 725 vop_t **vops; 726 struct vnode **vpp; 727 { 728 int s; 729 struct thread *td = curthread; /* XXX */ 730 struct vnode *vp = NULL; 731 struct mount *vnmp; 732 vm_object_t object; 733 734 s = splbio(); 735 /* 736 * Try to reuse vnodes if we hit the max. This situation only 737 * occurs in certain large-memory (2G+) situations. We cannot 738 * attempt to directly reclaim vnodes due to nasty recursion 739 * problems. 740 */ 741 if (vnlruproc_sig == 0 && numvnodes - freevnodes > desiredvnodes) { 742 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 743 wakeup(vnlruproc); 744 } 745 746 /* 747 * Attempt to reuse a vnode already on the free list, allocating 748 * a new vnode if we can't find one or if we have not reached a 749 * good minimum for good LRU performance. 750 */ 751 752 mtx_lock(&vnode_free_list_mtx); 753 754 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 755 int count; 756 757 for (count = 0; count < freevnodes; count++) { 758 vp = TAILQ_FIRST(&vnode_free_list); 759 if (vp == NULL || vp->v_usecount) 760 panic("getnewvnode: free vnode isn't"); 761 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 762 763 /* Don't recycle if we can't get the interlock */ 764 if (!mtx_trylock(&vp->v_interlock)) { 765 vp = NULL; 766 continue; 767 } 768 769 /* We should be able to immediately acquire this */ 770 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) 771 continue; 772 /* 773 * Don't recycle if we still have cached pages. 774 */ 775 if (VOP_GETVOBJECT(vp, &object) == 0 && 776 (object->resident_page_count || 777 object->ref_count)) { 778 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 779 v_freelist); 780 vp = NULL; 781 VOP_UNLOCK(vp, 0, td); 782 continue; 783 } 784 if (LIST_FIRST(&vp->v_cache_src)) { 785 /* 786 * note: nameileafonly sysctl is temporary, 787 * for debugging only, and will eventually be 788 * removed. 789 */ 790 if (nameileafonly > 0) { 791 /* 792 * Do not reuse namei-cached directory 793 * vnodes that have cached 794 * subdirectories. 795 */ 796 if (cache_leaf_test(vp) < 0) { 797 VOP_UNLOCK(vp, 0, td); 798 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 799 vp = NULL; 800 continue; 801 } 802 } else if (nameileafonly < 0 || 803 vmiodirenable == 0) { 804 /* 805 * Do not reuse namei-cached directory 806 * vnodes if nameileafonly is -1 or 807 * if VMIO backing for directories is 808 * turned off (otherwise we reuse them 809 * too quickly). 810 */ 811 VOP_UNLOCK(vp, 0, td); 812 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 813 vp = NULL; 814 continue; 815 } 816 } 817 /* 818 * Skip over it if its filesystem is being suspended. 819 */ 820 if (vn_start_write(vp, &vnmp, V_NOWAIT) == 0) 821 break; 822 VOP_UNLOCK(vp, 0, td); 823 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 824 vp = NULL; 825 } 826 } 827 if (vp) { 828 vp->v_flag |= VDOOMED; 829 vp->v_flag &= ~VFREE; 830 freevnodes--; 831 mtx_unlock(&vnode_free_list_mtx); 832 cache_purge(vp); 833 if (vp->v_type != VBAD) { 834 VOP_UNLOCK(vp, 0, td); 835 vgone(vp); 836 } else { 837 VOP_UNLOCK(vp, 0, td); 838 } 839 vn_finished_write(vnmp); 840 841 #ifdef INVARIANTS 842 { 843 int s; 844 845 if (vp->v_data) 846 panic("cleaned vnode isn't"); 847 s = splbio(); 848 if (vp->v_numoutput) 849 panic("Clean vnode has pending I/O's"); 850 splx(s); 851 if (vp->v_writecount != 0) 852 panic("Non-zero write count"); 853 } 854 #endif 855 if (vp->v_pollinfo) { 856 mtx_destroy(&vp->v_pollinfo->vpi_lock); 857 uma_zfree(vnodepoll_zone, vp->v_pollinfo); 858 } 859 vp->v_pollinfo = NULL; 860 vp->v_flag = 0; 861 vp->v_lastw = 0; 862 vp->v_lasta = 0; 863 vp->v_cstart = 0; 864 vp->v_clen = 0; 865 vp->v_socket = 0; 866 } else { 867 mtx_unlock(&vnode_free_list_mtx); 868 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 869 bzero((char *) vp, sizeof *vp); 870 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 871 vp->v_dd = vp; 872 cache_purge(vp); 873 LIST_INIT(&vp->v_cache_src); 874 TAILQ_INIT(&vp->v_cache_dst); 875 numvnodes++; 876 } 877 878 TAILQ_INIT(&vp->v_cleanblkhd); 879 TAILQ_INIT(&vp->v_dirtyblkhd); 880 vp->v_type = VNON; 881 vp->v_tag = tag; 882 vp->v_op = vops; 883 lockinit(&vp->v_lock, PVFS, "vnlock", VLKTIMEOUT, LK_NOPAUSE); 884 insmntque(vp, mp); 885 *vpp = vp; 886 vp->v_usecount = 1; 887 vp->v_data = 0; 888 889 splx(s); 890 891 #if 0 892 vnodeallocs++; 893 if (vnodeallocs % vnoderecycleperiod == 0 && 894 freevnodes < vnoderecycleminfreevn && 895 vnoderecyclemintotalvn < numvnodes) { 896 /* Recycle vnodes. */ 897 cache_purgeleafdirs(vnoderecyclenumber); 898 } 899 #endif 900 901 return (0); 902 } 903 904 /* 905 * Move a vnode from one mount queue to another. 906 */ 907 static void 908 insmntque(vp, mp) 909 register struct vnode *vp; 910 register struct mount *mp; 911 { 912 913 mtx_lock(&mntvnode_mtx); 914 /* 915 * Delete from old mount point vnode list, if on one. 916 */ 917 if (vp->v_mount != NULL) 918 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 919 /* 920 * Insert into list of vnodes for the new mount point, if available. 921 */ 922 if ((vp->v_mount = mp) == NULL) { 923 mtx_unlock(&mntvnode_mtx); 924 return; 925 } 926 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 927 mtx_unlock(&mntvnode_mtx); 928 } 929 930 /* 931 * Update outstanding I/O count and do wakeup if requested. 932 */ 933 void 934 vwakeup(bp) 935 register struct buf *bp; 936 { 937 register struct vnode *vp; 938 939 bp->b_flags &= ~B_WRITEINPROG; 940 if ((vp = bp->b_vp)) { 941 vp->v_numoutput--; 942 if (vp->v_numoutput < 0) 943 panic("vwakeup: neg numoutput"); 944 if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) { 945 vp->v_flag &= ~VBWAIT; 946 wakeup((caddr_t) &vp->v_numoutput); 947 } 948 } 949 } 950 951 /* 952 * Flush out and invalidate all buffers associated with a vnode. 953 * Called with the underlying object locked. 954 */ 955 int 956 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 957 register struct vnode *vp; 958 int flags; 959 struct ucred *cred; 960 struct thread *td; 961 int slpflag, slptimeo; 962 { 963 register struct buf *bp; 964 struct buf *nbp, *blist; 965 int s, error; 966 vm_object_t object; 967 968 GIANT_REQUIRED; 969 970 if (flags & V_SAVE) { 971 s = splbio(); 972 while (vp->v_numoutput) { 973 vp->v_flag |= VBWAIT; 974 error = tsleep((caddr_t)&vp->v_numoutput, 975 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 976 if (error) { 977 splx(s); 978 return (error); 979 } 980 } 981 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 982 splx(s); 983 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 984 return (error); 985 s = splbio(); 986 if (vp->v_numoutput > 0 || 987 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 988 panic("vinvalbuf: dirty bufs"); 989 } 990 splx(s); 991 } 992 s = splbio(); 993 for (;;) { 994 blist = TAILQ_FIRST(&vp->v_cleanblkhd); 995 if (!blist) 996 blist = TAILQ_FIRST(&vp->v_dirtyblkhd); 997 if (!blist) 998 break; 999 1000 for (bp = blist; bp; bp = nbp) { 1001 nbp = TAILQ_NEXT(bp, b_vnbufs); 1002 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1003 error = BUF_TIMELOCK(bp, 1004 LK_EXCLUSIVE | LK_SLEEPFAIL, 1005 "vinvalbuf", slpflag, slptimeo); 1006 if (error == ENOLCK) 1007 break; 1008 splx(s); 1009 return (error); 1010 } 1011 /* 1012 * XXX Since there are no node locks for NFS, I 1013 * believe there is a slight chance that a delayed 1014 * write will occur while sleeping just above, so 1015 * check for it. Note that vfs_bio_awrite expects 1016 * buffers to reside on a queue, while BUF_WRITE and 1017 * brelse do not. 1018 */ 1019 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1020 (flags & V_SAVE)) { 1021 1022 if (bp->b_vp == vp) { 1023 if (bp->b_flags & B_CLUSTEROK) { 1024 BUF_UNLOCK(bp); 1025 vfs_bio_awrite(bp); 1026 } else { 1027 bremfree(bp); 1028 bp->b_flags |= B_ASYNC; 1029 BUF_WRITE(bp); 1030 } 1031 } else { 1032 bremfree(bp); 1033 (void) BUF_WRITE(bp); 1034 } 1035 break; 1036 } 1037 bremfree(bp); 1038 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1039 bp->b_flags &= ~B_ASYNC; 1040 brelse(bp); 1041 } 1042 } 1043 1044 /* 1045 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1046 * have write I/O in-progress but if there is a VM object then the 1047 * VM object can also have read-I/O in-progress. 1048 */ 1049 do { 1050 while (vp->v_numoutput > 0) { 1051 vp->v_flag |= VBWAIT; 1052 tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0); 1053 } 1054 if (VOP_GETVOBJECT(vp, &object) == 0) { 1055 while (object->paging_in_progress) 1056 vm_object_pip_sleep(object, "vnvlbx"); 1057 } 1058 } while (vp->v_numoutput > 0); 1059 1060 splx(s); 1061 1062 /* 1063 * Destroy the copy in the VM cache, too. 1064 */ 1065 mtx_lock(&vp->v_interlock); 1066 if (VOP_GETVOBJECT(vp, &object) == 0) { 1067 vm_object_page_remove(object, 0, 0, 1068 (flags & V_SAVE) ? TRUE : FALSE); 1069 } 1070 mtx_unlock(&vp->v_interlock); 1071 1072 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd)) 1073 panic("vinvalbuf: flush failed"); 1074 return (0); 1075 } 1076 1077 /* 1078 * Truncate a file's buffer and pages to a specified length. This 1079 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1080 * sync activity. 1081 */ 1082 int 1083 vtruncbuf(vp, cred, td, length, blksize) 1084 register struct vnode *vp; 1085 struct ucred *cred; 1086 struct thread *td; 1087 off_t length; 1088 int blksize; 1089 { 1090 register struct buf *bp; 1091 struct buf *nbp; 1092 int s, anyfreed; 1093 int trunclbn; 1094 1095 /* 1096 * Round up to the *next* lbn. 1097 */ 1098 trunclbn = (length + blksize - 1) / blksize; 1099 1100 s = splbio(); 1101 restart: 1102 anyfreed = 1; 1103 for (;anyfreed;) { 1104 anyfreed = 0; 1105 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1106 nbp = TAILQ_NEXT(bp, b_vnbufs); 1107 if (bp->b_lblkno >= trunclbn) { 1108 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1109 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1110 goto restart; 1111 } else { 1112 bremfree(bp); 1113 bp->b_flags |= (B_INVAL | B_RELBUF); 1114 bp->b_flags &= ~B_ASYNC; 1115 brelse(bp); 1116 anyfreed = 1; 1117 } 1118 if (nbp && 1119 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1120 (nbp->b_vp != vp) || 1121 (nbp->b_flags & B_DELWRI))) { 1122 goto restart; 1123 } 1124 } 1125 } 1126 1127 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1128 nbp = TAILQ_NEXT(bp, b_vnbufs); 1129 if (bp->b_lblkno >= trunclbn) { 1130 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1131 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1132 goto restart; 1133 } else { 1134 bremfree(bp); 1135 bp->b_flags |= (B_INVAL | B_RELBUF); 1136 bp->b_flags &= ~B_ASYNC; 1137 brelse(bp); 1138 anyfreed = 1; 1139 } 1140 if (nbp && 1141 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1142 (nbp->b_vp != vp) || 1143 (nbp->b_flags & B_DELWRI) == 0)) { 1144 goto restart; 1145 } 1146 } 1147 } 1148 } 1149 1150 if (length > 0) { 1151 restartsync: 1152 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1153 nbp = TAILQ_NEXT(bp, b_vnbufs); 1154 if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { 1155 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1156 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1157 goto restart; 1158 } else { 1159 bremfree(bp); 1160 if (bp->b_vp == vp) { 1161 bp->b_flags |= B_ASYNC; 1162 } else { 1163 bp->b_flags &= ~B_ASYNC; 1164 } 1165 BUF_WRITE(bp); 1166 } 1167 goto restartsync; 1168 } 1169 1170 } 1171 } 1172 1173 while (vp->v_numoutput > 0) { 1174 vp->v_flag |= VBWAIT; 1175 tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0); 1176 } 1177 1178 splx(s); 1179 1180 vnode_pager_setsize(vp, length); 1181 1182 return (0); 1183 } 1184 1185 /* 1186 * Associate a buffer with a vnode. 1187 */ 1188 void 1189 bgetvp(vp, bp) 1190 register struct vnode *vp; 1191 register struct buf *bp; 1192 { 1193 int s; 1194 1195 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1196 1197 vhold(vp); 1198 bp->b_vp = vp; 1199 bp->b_dev = vn_todev(vp); 1200 /* 1201 * Insert onto list for new vnode. 1202 */ 1203 s = splbio(); 1204 bp->b_xflags |= BX_VNCLEAN; 1205 bp->b_xflags &= ~BX_VNDIRTY; 1206 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1207 splx(s); 1208 } 1209 1210 /* 1211 * Disassociate a buffer from a vnode. 1212 */ 1213 void 1214 brelvp(bp) 1215 register struct buf *bp; 1216 { 1217 struct vnode *vp; 1218 struct buflists *listheadp; 1219 int s; 1220 1221 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1222 1223 /* 1224 * Delete from old vnode list, if on one. 1225 */ 1226 vp = bp->b_vp; 1227 s = splbio(); 1228 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1229 if (bp->b_xflags & BX_VNDIRTY) 1230 listheadp = &vp->v_dirtyblkhd; 1231 else 1232 listheadp = &vp->v_cleanblkhd; 1233 TAILQ_REMOVE(listheadp, bp, b_vnbufs); 1234 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1235 } 1236 if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1237 vp->v_flag &= ~VONWORKLST; 1238 LIST_REMOVE(vp, v_synclist); 1239 } 1240 splx(s); 1241 bp->b_vp = (struct vnode *) 0; 1242 vdrop(vp); 1243 } 1244 1245 /* 1246 * Add an item to the syncer work queue. 1247 */ 1248 static void 1249 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1250 { 1251 int s, slot; 1252 1253 s = splbio(); 1254 1255 if (vp->v_flag & VONWORKLST) { 1256 LIST_REMOVE(vp, v_synclist); 1257 } 1258 1259 if (delay > syncer_maxdelay - 2) 1260 delay = syncer_maxdelay - 2; 1261 slot = (syncer_delayno + delay) & syncer_mask; 1262 1263 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1264 vp->v_flag |= VONWORKLST; 1265 splx(s); 1266 } 1267 1268 struct proc *updateproc; 1269 static void sched_sync(void); 1270 static struct kproc_desc up_kp = { 1271 "syncer", 1272 sched_sync, 1273 &updateproc 1274 }; 1275 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1276 1277 /* 1278 * System filesystem synchronizer daemon. 1279 */ 1280 void 1281 sched_sync(void) 1282 { 1283 struct synclist *slp; 1284 struct vnode *vp; 1285 struct mount *mp; 1286 long starttime; 1287 int s; 1288 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1289 1290 mtx_lock(&Giant); 1291 1292 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1293 SHUTDOWN_PRI_LAST); 1294 1295 for (;;) { 1296 kthread_suspend_check(td->td_proc); 1297 1298 starttime = time_second; 1299 1300 /* 1301 * Push files whose dirty time has expired. Be careful 1302 * of interrupt race on slp queue. 1303 */ 1304 s = splbio(); 1305 slp = &syncer_workitem_pending[syncer_delayno]; 1306 syncer_delayno += 1; 1307 if (syncer_delayno == syncer_maxdelay) 1308 syncer_delayno = 0; 1309 splx(s); 1310 1311 while ((vp = LIST_FIRST(slp)) != NULL) { 1312 if (VOP_ISLOCKED(vp, NULL) == 0 && 1313 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1314 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1315 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1316 VOP_UNLOCK(vp, 0, td); 1317 vn_finished_write(mp); 1318 } 1319 s = splbio(); 1320 if (LIST_FIRST(slp) == vp) { 1321 /* 1322 * Note: v_tag VT_VFS vps can remain on the 1323 * worklist too with no dirty blocks, but 1324 * since sync_fsync() moves it to a different 1325 * slot we are safe. 1326 */ 1327 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1328 !vn_isdisk(vp, NULL)) 1329 panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag); 1330 /* 1331 * Put us back on the worklist. The worklist 1332 * routine will remove us from our current 1333 * position and then add us back in at a later 1334 * position. 1335 */ 1336 vn_syncer_add_to_worklist(vp, syncdelay); 1337 } 1338 splx(s); 1339 } 1340 1341 /* 1342 * Do soft update processing. 1343 */ 1344 #ifdef SOFTUPDATES 1345 softdep_process_worklist(NULL); 1346 #endif 1347 1348 /* 1349 * The variable rushjob allows the kernel to speed up the 1350 * processing of the filesystem syncer process. A rushjob 1351 * value of N tells the filesystem syncer to process the next 1352 * N seconds worth of work on its queue ASAP. Currently rushjob 1353 * is used by the soft update code to speed up the filesystem 1354 * syncer process when the incore state is getting so far 1355 * ahead of the disk that the kernel memory pool is being 1356 * threatened with exhaustion. 1357 */ 1358 if (rushjob > 0) { 1359 rushjob -= 1; 1360 continue; 1361 } 1362 /* 1363 * If it has taken us less than a second to process the 1364 * current work, then wait. Otherwise start right over 1365 * again. We can still lose time if any single round 1366 * takes more than two seconds, but it does not really 1367 * matter as we are just trying to generally pace the 1368 * filesystem activity. 1369 */ 1370 if (time_second == starttime) 1371 tsleep(&lbolt, PPAUSE, "syncer", 0); 1372 } 1373 } 1374 1375 /* 1376 * Request the syncer daemon to speed up its work. 1377 * We never push it to speed up more than half of its 1378 * normal turn time, otherwise it could take over the cpu. 1379 * XXXKSE only one update? 1380 */ 1381 int 1382 speedup_syncer() 1383 { 1384 1385 mtx_lock_spin(&sched_lock); 1386 if (FIRST_THREAD_IN_PROC(updateproc)->td_wchan == &lbolt) /* XXXKSE */ 1387 setrunnable(FIRST_THREAD_IN_PROC(updateproc)); 1388 mtx_unlock_spin(&sched_lock); 1389 if (rushjob < syncdelay / 2) { 1390 rushjob += 1; 1391 stat_rush_requests += 1; 1392 return (1); 1393 } 1394 return(0); 1395 } 1396 1397 /* 1398 * Associate a p-buffer with a vnode. 1399 * 1400 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1401 * with the buffer. i.e. the bp has not been linked into the vnode or 1402 * ref-counted. 1403 */ 1404 void 1405 pbgetvp(vp, bp) 1406 register struct vnode *vp; 1407 register struct buf *bp; 1408 { 1409 1410 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1411 1412 bp->b_vp = vp; 1413 bp->b_flags |= B_PAGING; 1414 bp->b_dev = vn_todev(vp); 1415 } 1416 1417 /* 1418 * Disassociate a p-buffer from a vnode. 1419 */ 1420 void 1421 pbrelvp(bp) 1422 register struct buf *bp; 1423 { 1424 1425 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1426 1427 /* XXX REMOVE ME */ 1428 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1429 panic( 1430 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1431 bp, 1432 (int)bp->b_flags 1433 ); 1434 } 1435 bp->b_vp = (struct vnode *) 0; 1436 bp->b_flags &= ~B_PAGING; 1437 } 1438 1439 /* 1440 * Reassign a buffer from one vnode to another. 1441 * Used to assign file specific control information 1442 * (indirect blocks) to the vnode to which they belong. 1443 */ 1444 void 1445 reassignbuf(bp, newvp) 1446 register struct buf *bp; 1447 register struct vnode *newvp; 1448 { 1449 struct buflists *listheadp; 1450 int delay; 1451 int s; 1452 1453 if (newvp == NULL) { 1454 printf("reassignbuf: NULL"); 1455 return; 1456 } 1457 ++reassignbufcalls; 1458 1459 /* 1460 * B_PAGING flagged buffers cannot be reassigned because their vp 1461 * is not fully linked in. 1462 */ 1463 if (bp->b_flags & B_PAGING) 1464 panic("cannot reassign paging buffer"); 1465 1466 s = splbio(); 1467 /* 1468 * Delete from old vnode list, if on one. 1469 */ 1470 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1471 if (bp->b_xflags & BX_VNDIRTY) 1472 listheadp = &bp->b_vp->v_dirtyblkhd; 1473 else 1474 listheadp = &bp->b_vp->v_cleanblkhd; 1475 TAILQ_REMOVE(listheadp, bp, b_vnbufs); 1476 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1477 if (bp->b_vp != newvp) { 1478 vdrop(bp->b_vp); 1479 bp->b_vp = NULL; /* for clarification */ 1480 } 1481 } 1482 /* 1483 * If dirty, put on list of dirty buffers; otherwise insert onto list 1484 * of clean buffers. 1485 */ 1486 if (bp->b_flags & B_DELWRI) { 1487 struct buf *tbp; 1488 1489 listheadp = &newvp->v_dirtyblkhd; 1490 if ((newvp->v_flag & VONWORKLST) == 0) { 1491 switch (newvp->v_type) { 1492 case VDIR: 1493 delay = dirdelay; 1494 break; 1495 case VCHR: 1496 if (newvp->v_rdev->si_mountpoint != NULL) { 1497 delay = metadelay; 1498 break; 1499 } 1500 /* fall through */ 1501 default: 1502 delay = filedelay; 1503 } 1504 vn_syncer_add_to_worklist(newvp, delay); 1505 } 1506 bp->b_xflags |= BX_VNDIRTY; 1507 tbp = TAILQ_FIRST(listheadp); 1508 if (tbp == NULL || 1509 bp->b_lblkno == 0 || 1510 (bp->b_lblkno > 0 && tbp->b_lblkno < 0) || 1511 (bp->b_lblkno > 0 && bp->b_lblkno < tbp->b_lblkno)) { 1512 TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs); 1513 ++reassignbufsortgood; 1514 } else if (bp->b_lblkno < 0) { 1515 TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs); 1516 ++reassignbufsortgood; 1517 } else if (reassignbufmethod == 1) { 1518 /* 1519 * New sorting algorithm, only handle sequential case, 1520 * otherwise append to end (but before metadata) 1521 */ 1522 if ((tbp = gbincore(newvp, bp->b_lblkno - 1)) != NULL && 1523 (tbp->b_xflags & BX_VNDIRTY)) { 1524 /* 1525 * Found the best place to insert the buffer 1526 */ 1527 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1528 ++reassignbufsortgood; 1529 } else { 1530 /* 1531 * Missed, append to end, but before meta-data. 1532 * We know that the head buffer in the list is 1533 * not meta-data due to prior conditionals. 1534 * 1535 * Indirect effects: NFS second stage write 1536 * tends to wind up here, giving maximum 1537 * distance between the unstable write and the 1538 * commit rpc. 1539 */ 1540 tbp = TAILQ_LAST(listheadp, buflists); 1541 while (tbp && tbp->b_lblkno < 0) 1542 tbp = TAILQ_PREV(tbp, buflists, b_vnbufs); 1543 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1544 ++reassignbufsortbad; 1545 } 1546 } else { 1547 /* 1548 * Old sorting algorithm, scan queue and insert 1549 */ 1550 struct buf *ttbp; 1551 while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) && 1552 (ttbp->b_lblkno < bp->b_lblkno)) { 1553 ++reassignbufloops; 1554 tbp = ttbp; 1555 } 1556 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1557 } 1558 } else { 1559 bp->b_xflags |= BX_VNCLEAN; 1560 TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs); 1561 if ((newvp->v_flag & VONWORKLST) && 1562 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1563 newvp->v_flag &= ~VONWORKLST; 1564 LIST_REMOVE(newvp, v_synclist); 1565 } 1566 } 1567 if (bp->b_vp != newvp) { 1568 bp->b_vp = newvp; 1569 vhold(bp->b_vp); 1570 } 1571 splx(s); 1572 } 1573 1574 /* 1575 * Create a vnode for a device. 1576 * Used for mounting the root filesystem. 1577 */ 1578 int 1579 bdevvp(dev, vpp) 1580 dev_t dev; 1581 struct vnode **vpp; 1582 { 1583 register struct vnode *vp; 1584 struct vnode *nvp; 1585 int error; 1586 1587 if (dev == NODEV) { 1588 *vpp = NULLVP; 1589 return (ENXIO); 1590 } 1591 if (vfinddev(dev, VCHR, vpp)) 1592 return (0); 1593 error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp); 1594 if (error) { 1595 *vpp = NULLVP; 1596 return (error); 1597 } 1598 vp = nvp; 1599 vp->v_type = VCHR; 1600 addalias(vp, dev); 1601 *vpp = vp; 1602 return (0); 1603 } 1604 1605 /* 1606 * Add vnode to the alias list hung off the dev_t. 1607 * 1608 * The reason for this gunk is that multiple vnodes can reference 1609 * the same physical device, so checking vp->v_usecount to see 1610 * how many users there are is inadequate; the v_usecount for 1611 * the vnodes need to be accumulated. vcount() does that. 1612 */ 1613 struct vnode * 1614 addaliasu(nvp, nvp_rdev) 1615 struct vnode *nvp; 1616 udev_t nvp_rdev; 1617 { 1618 struct vnode *ovp; 1619 vop_t **ops; 1620 dev_t dev; 1621 1622 if (nvp->v_type == VBLK) 1623 return (nvp); 1624 if (nvp->v_type != VCHR) 1625 panic("addaliasu on non-special vnode"); 1626 dev = udev2dev(nvp_rdev, 0); 1627 /* 1628 * Check to see if we have a bdevvp vnode with no associated 1629 * filesystem. If so, we want to associate the filesystem of 1630 * the new newly instigated vnode with the bdevvp vnode and 1631 * discard the newly created vnode rather than leaving the 1632 * bdevvp vnode lying around with no associated filesystem. 1633 */ 1634 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 1635 addalias(nvp, dev); 1636 return (nvp); 1637 } 1638 /* 1639 * Discard unneeded vnode, but save its node specific data. 1640 * Note that if there is a lock, it is carried over in the 1641 * node specific data to the replacement vnode. 1642 */ 1643 vref(ovp); 1644 ovp->v_data = nvp->v_data; 1645 ovp->v_tag = nvp->v_tag; 1646 nvp->v_data = NULL; 1647 lockinit(&ovp->v_lock, PVFS, nvp->v_lock.lk_wmesg, 1648 nvp->v_lock.lk_timo, nvp->v_lock.lk_flags & LK_EXTFLG_MASK); 1649 if (nvp->v_vnlock) 1650 ovp->v_vnlock = &ovp->v_lock; 1651 ops = ovp->v_op; 1652 ovp->v_op = nvp->v_op; 1653 if (VOP_ISLOCKED(nvp, curthread)) { 1654 VOP_UNLOCK(nvp, 0, curthread); 1655 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1656 } 1657 nvp->v_op = ops; 1658 insmntque(ovp, nvp->v_mount); 1659 vrele(nvp); 1660 vgone(nvp); 1661 return (ovp); 1662 } 1663 1664 /* This is a local helper function that do the same as addaliasu, but for a 1665 * dev_t instead of an udev_t. */ 1666 static void 1667 addalias(nvp, dev) 1668 struct vnode *nvp; 1669 dev_t dev; 1670 { 1671 1672 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1673 nvp->v_rdev = dev; 1674 mtx_lock(&spechash_mtx); 1675 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1676 mtx_unlock(&spechash_mtx); 1677 } 1678 1679 /* 1680 * Grab a particular vnode from the free list, increment its 1681 * reference count and lock it. The vnode lock bit is set if the 1682 * vnode is being eliminated in vgone. The process is awakened 1683 * when the transition is completed, and an error returned to 1684 * indicate that the vnode is no longer usable (possibly having 1685 * been changed to a new filesystem type). 1686 */ 1687 int 1688 vget(vp, flags, td) 1689 register struct vnode *vp; 1690 int flags; 1691 struct thread *td; 1692 { 1693 int error; 1694 1695 /* 1696 * If the vnode is in the process of being cleaned out for 1697 * another use, we wait for the cleaning to finish and then 1698 * return failure. Cleaning is determined by checking that 1699 * the VXLOCK flag is set. 1700 */ 1701 if ((flags & LK_INTERLOCK) == 0) 1702 mtx_lock(&vp->v_interlock); 1703 if (vp->v_flag & VXLOCK) { 1704 if (vp->v_vxproc == curthread) { 1705 #if 0 1706 /* this can now occur in normal operation */ 1707 log(LOG_INFO, "VXLOCK interlock avoided\n"); 1708 #endif 1709 } else { 1710 vp->v_flag |= VXWANT; 1711 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 1712 "vget", 0); 1713 return (ENOENT); 1714 } 1715 } 1716 1717 vp->v_usecount++; 1718 1719 if (VSHOULDBUSY(vp)) 1720 vbusy(vp); 1721 if (flags & LK_TYPE_MASK) { 1722 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1723 /* 1724 * must expand vrele here because we do not want 1725 * to call VOP_INACTIVE if the reference count 1726 * drops back to zero since it was never really 1727 * active. We must remove it from the free list 1728 * before sleeping so that multiple processes do 1729 * not try to recycle it. 1730 */ 1731 mtx_lock(&vp->v_interlock); 1732 vp->v_usecount--; 1733 if (VSHOULDFREE(vp)) 1734 vfree(vp); 1735 else 1736 vlruvp(vp); 1737 mtx_unlock(&vp->v_interlock); 1738 } 1739 return (error); 1740 } 1741 mtx_unlock(&vp->v_interlock); 1742 return (0); 1743 } 1744 1745 /* 1746 * Increase the reference count of a vnode. 1747 */ 1748 void 1749 vref(struct vnode *vp) 1750 { 1751 mtx_lock(&vp->v_interlock); 1752 vp->v_usecount++; 1753 mtx_unlock(&vp->v_interlock); 1754 } 1755 1756 /* 1757 * Vnode put/release. 1758 * If count drops to zero, call inactive routine and return to freelist. 1759 */ 1760 void 1761 vrele(vp) 1762 struct vnode *vp; 1763 { 1764 struct thread *td = curthread; /* XXX */ 1765 1766 KASSERT(vp != NULL, ("vrele: null vp")); 1767 1768 mtx_lock(&vp->v_interlock); 1769 1770 /* Skip this v_writecount check if we're going to panic below. */ 1771 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1772 ("vrele: missed vn_close")); 1773 1774 if (vp->v_usecount > 1) { 1775 1776 vp->v_usecount--; 1777 mtx_unlock(&vp->v_interlock); 1778 1779 return; 1780 } 1781 1782 if (vp->v_usecount == 1) { 1783 vp->v_usecount--; 1784 /* 1785 * We must call VOP_INACTIVE with the node locked. 1786 * If we are doing a vput, the node is already locked, 1787 * but, in the case of vrele, we must explicitly lock 1788 * the vnode before calling VOP_INACTIVE. 1789 */ 1790 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) 1791 VOP_INACTIVE(vp, td); 1792 if (VSHOULDFREE(vp)) 1793 vfree(vp); 1794 else 1795 vlruvp(vp); 1796 1797 } else { 1798 #ifdef DIAGNOSTIC 1799 vprint("vrele: negative ref count", vp); 1800 mtx_unlock(&vp->v_interlock); 1801 #endif 1802 panic("vrele: negative ref cnt"); 1803 } 1804 } 1805 1806 /* 1807 * Release an already locked vnode. This give the same effects as 1808 * unlock+vrele(), but takes less time and avoids releasing and 1809 * re-aquiring the lock (as vrele() aquires the lock internally.) 1810 */ 1811 void 1812 vput(vp) 1813 struct vnode *vp; 1814 { 1815 struct thread *td = curthread; /* XXX */ 1816 1817 GIANT_REQUIRED; 1818 1819 KASSERT(vp != NULL, ("vput: null vp")); 1820 mtx_lock(&vp->v_interlock); 1821 /* Skip this v_writecount check if we're going to panic below. */ 1822 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1823 ("vput: missed vn_close")); 1824 1825 if (vp->v_usecount > 1) { 1826 vp->v_usecount--; 1827 VOP_UNLOCK(vp, LK_INTERLOCK, td); 1828 return; 1829 } 1830 1831 if (vp->v_usecount == 1) { 1832 vp->v_usecount--; 1833 /* 1834 * We must call VOP_INACTIVE with the node locked. 1835 * If we are doing a vput, the node is already locked, 1836 * so we just need to release the vnode mutex. 1837 */ 1838 mtx_unlock(&vp->v_interlock); 1839 VOP_INACTIVE(vp, td); 1840 if (VSHOULDFREE(vp)) 1841 vfree(vp); 1842 else 1843 vlruvp(vp); 1844 1845 } else { 1846 #ifdef DIAGNOSTIC 1847 vprint("vput: negative ref count", vp); 1848 #endif 1849 panic("vput: negative ref cnt"); 1850 } 1851 } 1852 1853 /* 1854 * Somebody doesn't want the vnode recycled. 1855 */ 1856 void 1857 vhold(vp) 1858 register struct vnode *vp; 1859 { 1860 int s; 1861 1862 s = splbio(); 1863 vp->v_holdcnt++; 1864 if (VSHOULDBUSY(vp)) 1865 vbusy(vp); 1866 splx(s); 1867 } 1868 1869 /* 1870 * Note that there is one less who cares about this vnode. vdrop() is the 1871 * opposite of vhold(). 1872 */ 1873 void 1874 vdrop(vp) 1875 register struct vnode *vp; 1876 { 1877 int s; 1878 1879 s = splbio(); 1880 if (vp->v_holdcnt <= 0) 1881 panic("vdrop: holdcnt"); 1882 vp->v_holdcnt--; 1883 if (VSHOULDFREE(vp)) 1884 vfree(vp); 1885 else 1886 vlruvp(vp); 1887 splx(s); 1888 } 1889 1890 /* 1891 * Remove any vnodes in the vnode table belonging to mount point mp. 1892 * 1893 * If FORCECLOSE is not specified, there should not be any active ones, 1894 * return error if any are found (nb: this is a user error, not a 1895 * system error). If FORCECLOSE is specified, detach any active vnodes 1896 * that are found. 1897 * 1898 * If WRITECLOSE is set, only flush out regular file vnodes open for 1899 * writing. 1900 * 1901 * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped. 1902 * 1903 * `rootrefs' specifies the base reference count for the root vnode 1904 * of this filesystem. The root vnode is considered busy if its 1905 * v_usecount exceeds this value. On a successful return, vflush() 1906 * will call vrele() on the root vnode exactly rootrefs times. 1907 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 1908 * be zero. 1909 */ 1910 #ifdef DIAGNOSTIC 1911 static int busyprt = 0; /* print out busy vnodes */ 1912 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 1913 #endif 1914 1915 int 1916 vflush(mp, rootrefs, flags) 1917 struct mount *mp; 1918 int rootrefs; 1919 int flags; 1920 { 1921 struct thread *td = curthread; /* XXX */ 1922 struct vnode *vp, *nvp, *rootvp = NULL; 1923 struct vattr vattr; 1924 int busy = 0, error; 1925 1926 if (rootrefs > 0) { 1927 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 1928 ("vflush: bad args")); 1929 /* 1930 * Get the filesystem root vnode. We can vput() it 1931 * immediately, since with rootrefs > 0, it won't go away. 1932 */ 1933 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 1934 return (error); 1935 vput(rootvp); 1936 } 1937 mtx_lock(&mntvnode_mtx); 1938 loop: 1939 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 1940 /* 1941 * Make sure this vnode wasn't reclaimed in getnewvnode(). 1942 * Start over if it has (it won't be on the list anymore). 1943 */ 1944 if (vp->v_mount != mp) 1945 goto loop; 1946 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1947 1948 mtx_unlock(&mntvnode_mtx); 1949 mtx_lock(&vp->v_interlock); 1950 /* 1951 * Skip over a vnodes marked VSYSTEM. 1952 */ 1953 if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) { 1954 mtx_unlock(&vp->v_interlock); 1955 mtx_lock(&mntvnode_mtx); 1956 continue; 1957 } 1958 /* 1959 * If WRITECLOSE is set, flush out unlinked but still open 1960 * files (even if open only for reading) and regular file 1961 * vnodes open for writing. 1962 */ 1963 if ((flags & WRITECLOSE) && 1964 (vp->v_type == VNON || 1965 (VOP_GETATTR(vp, &vattr, td->td_ucred, td) == 0 && 1966 vattr.va_nlink > 0)) && 1967 (vp->v_writecount == 0 || vp->v_type != VREG)) { 1968 mtx_unlock(&vp->v_interlock); 1969 mtx_lock(&mntvnode_mtx); 1970 continue; 1971 } 1972 1973 /* 1974 * With v_usecount == 0, all we need to do is clear out the 1975 * vnode data structures and we are done. 1976 */ 1977 if (vp->v_usecount == 0) { 1978 vgonel(vp, td); 1979 mtx_lock(&mntvnode_mtx); 1980 continue; 1981 } 1982 1983 /* 1984 * If FORCECLOSE is set, forcibly close the vnode. For block 1985 * or character devices, revert to an anonymous device. For 1986 * all other files, just kill them. 1987 */ 1988 if (flags & FORCECLOSE) { 1989 if (vp->v_type != VCHR) { 1990 vgonel(vp, td); 1991 } else { 1992 vclean(vp, 0, td); 1993 vp->v_op = spec_vnodeop_p; 1994 insmntque(vp, (struct mount *) 0); 1995 } 1996 mtx_lock(&mntvnode_mtx); 1997 continue; 1998 } 1999 #ifdef DIAGNOSTIC 2000 if (busyprt) 2001 vprint("vflush: busy vnode", vp); 2002 #endif 2003 mtx_unlock(&vp->v_interlock); 2004 mtx_lock(&mntvnode_mtx); 2005 busy++; 2006 } 2007 mtx_unlock(&mntvnode_mtx); 2008 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2009 /* 2010 * If just the root vnode is busy, and if its refcount 2011 * is equal to `rootrefs', then go ahead and kill it. 2012 */ 2013 mtx_lock(&rootvp->v_interlock); 2014 KASSERT(busy > 0, ("vflush: not busy")); 2015 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2016 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2017 vgonel(rootvp, td); 2018 busy = 0; 2019 } else 2020 mtx_unlock(&rootvp->v_interlock); 2021 } 2022 if (busy) 2023 return (EBUSY); 2024 for (; rootrefs > 0; rootrefs--) 2025 vrele(rootvp); 2026 return (0); 2027 } 2028 2029 /* 2030 * This moves a now (likely recyclable) vnode to the end of the 2031 * mountlist. XXX However, it is temporarily disabled until we 2032 * can clean up ffs_sync() and friends, which have loop restart 2033 * conditions which this code causes to operate O(N^2). 2034 */ 2035 static void 2036 vlruvp(struct vnode *vp) 2037 { 2038 #if 0 2039 struct mount *mp; 2040 2041 if ((mp = vp->v_mount) != NULL) { 2042 mtx_lock(&mntvnode_mtx); 2043 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2044 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2045 mtx_unlock(&mntvnode_mtx); 2046 } 2047 #endif 2048 } 2049 2050 /* 2051 * Disassociate the underlying filesystem from a vnode. 2052 */ 2053 static void 2054 vclean(vp, flags, td) 2055 struct vnode *vp; 2056 int flags; 2057 struct thread *td; 2058 { 2059 int active; 2060 2061 /* 2062 * Check to see if the vnode is in use. If so we have to reference it 2063 * before we clean it out so that its count cannot fall to zero and 2064 * generate a race against ourselves to recycle it. 2065 */ 2066 if ((active = vp->v_usecount)) 2067 vp->v_usecount++; 2068 2069 /* 2070 * Prevent the vnode from being recycled or brought into use while we 2071 * clean it out. 2072 */ 2073 if (vp->v_flag & VXLOCK) 2074 panic("vclean: deadlock"); 2075 vp->v_flag |= VXLOCK; 2076 vp->v_vxproc = curthread; 2077 /* 2078 * Even if the count is zero, the VOP_INACTIVE routine may still 2079 * have the object locked while it cleans it out. The VOP_LOCK 2080 * ensures that the VOP_INACTIVE routine is done with its work. 2081 * For active vnodes, it ensures that no other activity can 2082 * occur while the underlying object is being cleaned out. 2083 */ 2084 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2085 2086 /* 2087 * Clean out any buffers associated with the vnode. 2088 * If the flush fails, just toss the buffers. 2089 */ 2090 if (flags & DOCLOSE) { 2091 if (TAILQ_FIRST(&vp->v_dirtyblkhd) != NULL) 2092 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2093 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2094 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2095 } 2096 2097 VOP_DESTROYVOBJECT(vp); 2098 2099 /* 2100 * If purging an active vnode, it must be closed and 2101 * deactivated before being reclaimed. Note that the 2102 * VOP_INACTIVE will unlock the vnode. 2103 */ 2104 if (active) { 2105 if (flags & DOCLOSE) 2106 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2107 VOP_INACTIVE(vp, td); 2108 } else { 2109 /* 2110 * Any other processes trying to obtain this lock must first 2111 * wait for VXLOCK to clear, then call the new lock operation. 2112 */ 2113 VOP_UNLOCK(vp, 0, td); 2114 } 2115 /* 2116 * Reclaim the vnode. 2117 */ 2118 if (VOP_RECLAIM(vp, td)) 2119 panic("vclean: cannot reclaim"); 2120 2121 if (active) { 2122 /* 2123 * Inline copy of vrele() since VOP_INACTIVE 2124 * has already been called. 2125 */ 2126 mtx_lock(&vp->v_interlock); 2127 if (--vp->v_usecount <= 0) { 2128 #ifdef DIAGNOSTIC 2129 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2130 vprint("vclean: bad ref count", vp); 2131 panic("vclean: ref cnt"); 2132 } 2133 #endif 2134 vfree(vp); 2135 } 2136 mtx_unlock(&vp->v_interlock); 2137 } 2138 2139 cache_purge(vp); 2140 vp->v_vnlock = NULL; 2141 lockdestroy(&vp->v_lock); 2142 2143 if (VSHOULDFREE(vp)) 2144 vfree(vp); 2145 2146 /* 2147 * Done with purge, notify sleepers of the grim news. 2148 */ 2149 vp->v_op = dead_vnodeop_p; 2150 if (vp->v_pollinfo != NULL) 2151 vn_pollgone(vp); 2152 vp->v_tag = VT_NON; 2153 vp->v_flag &= ~VXLOCK; 2154 vp->v_vxproc = NULL; 2155 if (vp->v_flag & VXWANT) { 2156 vp->v_flag &= ~VXWANT; 2157 wakeup((caddr_t) vp); 2158 } 2159 } 2160 2161 /* 2162 * Eliminate all activity associated with the requested vnode 2163 * and with all vnodes aliased to the requested vnode. 2164 */ 2165 int 2166 vop_revoke(ap) 2167 struct vop_revoke_args /* { 2168 struct vnode *a_vp; 2169 int a_flags; 2170 } */ *ap; 2171 { 2172 struct vnode *vp, *vq; 2173 dev_t dev; 2174 2175 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2176 2177 vp = ap->a_vp; 2178 /* 2179 * If a vgone (or vclean) is already in progress, 2180 * wait until it is done and return. 2181 */ 2182 if (vp->v_flag & VXLOCK) { 2183 vp->v_flag |= VXWANT; 2184 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 2185 "vop_revokeall", 0); 2186 return (0); 2187 } 2188 dev = vp->v_rdev; 2189 for (;;) { 2190 mtx_lock(&spechash_mtx); 2191 vq = SLIST_FIRST(&dev->si_hlist); 2192 mtx_unlock(&spechash_mtx); 2193 if (!vq) 2194 break; 2195 vgone(vq); 2196 } 2197 return (0); 2198 } 2199 2200 /* 2201 * Recycle an unused vnode to the front of the free list. 2202 * Release the passed interlock if the vnode will be recycled. 2203 */ 2204 int 2205 vrecycle(vp, inter_lkp, td) 2206 struct vnode *vp; 2207 struct mtx *inter_lkp; 2208 struct thread *td; 2209 { 2210 2211 mtx_lock(&vp->v_interlock); 2212 if (vp->v_usecount == 0) { 2213 if (inter_lkp) { 2214 mtx_unlock(inter_lkp); 2215 } 2216 vgonel(vp, td); 2217 return (1); 2218 } 2219 mtx_unlock(&vp->v_interlock); 2220 return (0); 2221 } 2222 2223 /* 2224 * Eliminate all activity associated with a vnode 2225 * in preparation for reuse. 2226 */ 2227 void 2228 vgone(vp) 2229 register struct vnode *vp; 2230 { 2231 struct thread *td = curthread; /* XXX */ 2232 2233 mtx_lock(&vp->v_interlock); 2234 vgonel(vp, td); 2235 } 2236 2237 /* 2238 * vgone, with the vp interlock held. 2239 */ 2240 void 2241 vgonel(vp, td) 2242 struct vnode *vp; 2243 struct thread *td; 2244 { 2245 int s; 2246 2247 /* 2248 * If a vgone (or vclean) is already in progress, 2249 * wait until it is done and return. 2250 */ 2251 if (vp->v_flag & VXLOCK) { 2252 vp->v_flag |= VXWANT; 2253 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 2254 "vgone", 0); 2255 return; 2256 } 2257 2258 /* 2259 * Clean out the filesystem specific data. 2260 */ 2261 vclean(vp, DOCLOSE, td); 2262 mtx_lock(&vp->v_interlock); 2263 2264 /* 2265 * Delete from old mount point vnode list, if on one. 2266 */ 2267 if (vp->v_mount != NULL) 2268 insmntque(vp, (struct mount *)0); 2269 /* 2270 * If special device, remove it from special device alias list 2271 * if it is on one. 2272 */ 2273 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2274 mtx_lock(&spechash_mtx); 2275 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2276 freedev(vp->v_rdev); 2277 mtx_unlock(&spechash_mtx); 2278 vp->v_rdev = NULL; 2279 } 2280 2281 /* 2282 * If it is on the freelist and not already at the head, 2283 * move it to the head of the list. The test of the 2284 * VDOOMED flag and the reference count of zero is because 2285 * it will be removed from the free list by getnewvnode, 2286 * but will not have its reference count incremented until 2287 * after calling vgone. If the reference count were 2288 * incremented first, vgone would (incorrectly) try to 2289 * close the previous instance of the underlying object. 2290 */ 2291 if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) { 2292 s = splbio(); 2293 mtx_lock(&vnode_free_list_mtx); 2294 if (vp->v_flag & VFREE) 2295 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2296 else 2297 freevnodes++; 2298 vp->v_flag |= VFREE; 2299 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2300 mtx_unlock(&vnode_free_list_mtx); 2301 splx(s); 2302 } 2303 2304 vp->v_type = VBAD; 2305 mtx_unlock(&vp->v_interlock); 2306 } 2307 2308 /* 2309 * Lookup a vnode by device number. 2310 */ 2311 int 2312 vfinddev(dev, type, vpp) 2313 dev_t dev; 2314 enum vtype type; 2315 struct vnode **vpp; 2316 { 2317 struct vnode *vp; 2318 2319 mtx_lock(&spechash_mtx); 2320 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2321 if (type == vp->v_type) { 2322 *vpp = vp; 2323 mtx_unlock(&spechash_mtx); 2324 return (1); 2325 } 2326 } 2327 mtx_unlock(&spechash_mtx); 2328 return (0); 2329 } 2330 2331 /* 2332 * Calculate the total number of references to a special device. 2333 */ 2334 int 2335 vcount(vp) 2336 struct vnode *vp; 2337 { 2338 struct vnode *vq; 2339 int count; 2340 2341 count = 0; 2342 mtx_lock(&spechash_mtx); 2343 SLIST_FOREACH(vq, &vp->v_rdev->si_hlist, v_specnext) 2344 count += vq->v_usecount; 2345 mtx_unlock(&spechash_mtx); 2346 return (count); 2347 } 2348 2349 /* 2350 * Same as above, but using the dev_t as argument 2351 */ 2352 int 2353 count_dev(dev) 2354 dev_t dev; 2355 { 2356 struct vnode *vp; 2357 2358 vp = SLIST_FIRST(&dev->si_hlist); 2359 if (vp == NULL) 2360 return (0); 2361 return(vcount(vp)); 2362 } 2363 2364 /* 2365 * Print out a description of a vnode. 2366 */ 2367 static char *typename[] = 2368 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2369 2370 void 2371 vprint(label, vp) 2372 char *label; 2373 struct vnode *vp; 2374 { 2375 char buf[96]; 2376 2377 if (label != NULL) 2378 printf("%s: %p: ", label, (void *)vp); 2379 else 2380 printf("%p: ", (void *)vp); 2381 printf("type %s, usecount %d, writecount %d, refcount %d,", 2382 typename[vp->v_type], vp->v_usecount, vp->v_writecount, 2383 vp->v_holdcnt); 2384 buf[0] = '\0'; 2385 if (vp->v_flag & VROOT) 2386 strcat(buf, "|VROOT"); 2387 if (vp->v_flag & VTEXT) 2388 strcat(buf, "|VTEXT"); 2389 if (vp->v_flag & VSYSTEM) 2390 strcat(buf, "|VSYSTEM"); 2391 if (vp->v_flag & VXLOCK) 2392 strcat(buf, "|VXLOCK"); 2393 if (vp->v_flag & VXWANT) 2394 strcat(buf, "|VXWANT"); 2395 if (vp->v_flag & VBWAIT) 2396 strcat(buf, "|VBWAIT"); 2397 if (vp->v_flag & VDOOMED) 2398 strcat(buf, "|VDOOMED"); 2399 if (vp->v_flag & VFREE) 2400 strcat(buf, "|VFREE"); 2401 if (vp->v_flag & VOBJBUF) 2402 strcat(buf, "|VOBJBUF"); 2403 if (buf[0] != '\0') 2404 printf(" flags (%s)", &buf[1]); 2405 if (vp->v_data == NULL) { 2406 printf("\n"); 2407 } else { 2408 printf("\n\t"); 2409 VOP_PRINT(vp); 2410 } 2411 } 2412 2413 #ifdef DDB 2414 #include <ddb/ddb.h> 2415 /* 2416 * List all of the locked vnodes in the system. 2417 * Called when debugging the kernel. 2418 */ 2419 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes) 2420 { 2421 struct thread *td = curthread; /* XXX */ 2422 struct mount *mp, *nmp; 2423 struct vnode *vp; 2424 2425 printf("Locked vnodes\n"); 2426 mtx_lock(&mountlist_mtx); 2427 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2428 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2429 nmp = TAILQ_NEXT(mp, mnt_list); 2430 continue; 2431 } 2432 mtx_lock(&mntvnode_mtx); 2433 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2434 if (VOP_ISLOCKED(vp, NULL)) 2435 vprint((char *)0, vp); 2436 } 2437 mtx_unlock(&mntvnode_mtx); 2438 mtx_lock(&mountlist_mtx); 2439 nmp = TAILQ_NEXT(mp, mnt_list); 2440 vfs_unbusy(mp, td); 2441 } 2442 mtx_unlock(&mountlist_mtx); 2443 } 2444 #endif 2445 2446 /* 2447 * Top level filesystem related information gathering. 2448 */ 2449 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2450 2451 static int 2452 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2453 { 2454 int *name = (int *)arg1 - 1; /* XXX */ 2455 u_int namelen = arg2 + 1; /* XXX */ 2456 struct vfsconf *vfsp; 2457 2458 #if 1 || defined(COMPAT_PRELITE2) 2459 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2460 if (namelen == 1) 2461 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2462 #endif 2463 2464 /* XXX the below code does not compile; vfs_sysctl does not exist. */ 2465 #ifdef notyet 2466 /* all sysctl names at this level are at least name and field */ 2467 if (namelen < 2) 2468 return (ENOTDIR); /* overloaded */ 2469 if (name[0] != VFS_GENERIC) { 2470 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2471 if (vfsp->vfc_typenum == name[0]) 2472 break; 2473 if (vfsp == NULL) 2474 return (EOPNOTSUPP); 2475 return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1, 2476 oldp, oldlenp, newp, newlen, td)); 2477 } 2478 #endif 2479 switch (name[1]) { 2480 case VFS_MAXTYPENUM: 2481 if (namelen != 2) 2482 return (ENOTDIR); 2483 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2484 case VFS_CONF: 2485 if (namelen != 3) 2486 return (ENOTDIR); /* overloaded */ 2487 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2488 if (vfsp->vfc_typenum == name[2]) 2489 break; 2490 if (vfsp == NULL) 2491 return (EOPNOTSUPP); 2492 return (SYSCTL_OUT(req, vfsp, sizeof *vfsp)); 2493 } 2494 return (EOPNOTSUPP); 2495 } 2496 2497 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl, 2498 "Generic filesystem"); 2499 2500 #if 1 || defined(COMPAT_PRELITE2) 2501 2502 static int 2503 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2504 { 2505 int error; 2506 struct vfsconf *vfsp; 2507 struct ovfsconf ovfs; 2508 2509 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 2510 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2511 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2512 ovfs.vfc_index = vfsp->vfc_typenum; 2513 ovfs.vfc_refcount = vfsp->vfc_refcount; 2514 ovfs.vfc_flags = vfsp->vfc_flags; 2515 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2516 if (error) 2517 return error; 2518 } 2519 return 0; 2520 } 2521 2522 #endif /* 1 || COMPAT_PRELITE2 */ 2523 2524 #if COMPILING_LINT 2525 #define KINFO_VNODESLOP 10 2526 /* 2527 * Dump vnode list (via sysctl). 2528 * Copyout address of vnode followed by vnode. 2529 */ 2530 /* ARGSUSED */ 2531 static int 2532 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2533 { 2534 struct thread *td = curthread; /* XXX */ 2535 struct mount *mp, *nmp; 2536 struct vnode *nvp, *vp; 2537 int error; 2538 2539 #define VPTRSZ sizeof (struct vnode *) 2540 #define VNODESZ sizeof (struct vnode) 2541 2542 req->lock = 0; 2543 if (!req->oldptr) /* Make an estimate */ 2544 return (SYSCTL_OUT(req, 0, 2545 (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ))); 2546 2547 mtx_lock(&mountlist_mtx); 2548 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2549 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2550 nmp = TAILQ_NEXT(mp, mnt_list); 2551 continue; 2552 } 2553 mtx_lock(&mntvnode_mtx); 2554 again: 2555 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2556 vp != NULL; 2557 vp = nvp) { 2558 /* 2559 * Check that the vp is still associated with 2560 * this filesystem. RACE: could have been 2561 * recycled onto the same filesystem. 2562 */ 2563 if (vp->v_mount != mp) 2564 goto again; 2565 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2566 mtx_unlock(&mntvnode_mtx); 2567 if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) || 2568 (error = SYSCTL_OUT(req, vp, VNODESZ))) 2569 return (error); 2570 mtx_lock(&mntvnode_mtx); 2571 } 2572 mtx_unlock(&mntvnode_mtx); 2573 mtx_lock(&mountlist_mtx); 2574 nmp = TAILQ_NEXT(mp, mnt_list); 2575 vfs_unbusy(mp, td); 2576 } 2577 mtx_unlock(&mountlist_mtx); 2578 2579 return (0); 2580 } 2581 2582 /* 2583 * XXX 2584 * Exporting the vnode list on large systems causes them to crash. 2585 * Exporting the vnode list on medium systems causes sysctl to coredump. 2586 */ 2587 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2588 0, 0, sysctl_vnode, "S,vnode", ""); 2589 #endif 2590 2591 /* 2592 * Check to see if a filesystem is mounted on a block device. 2593 */ 2594 int 2595 vfs_mountedon(vp) 2596 struct vnode *vp; 2597 { 2598 2599 if (vp->v_rdev->si_mountpoint != NULL) 2600 return (EBUSY); 2601 return (0); 2602 } 2603 2604 /* 2605 * Unmount all filesystems. The list is traversed in reverse order 2606 * of mounting to avoid dependencies. 2607 */ 2608 void 2609 vfs_unmountall() 2610 { 2611 struct mount *mp; 2612 struct thread *td; 2613 int error; 2614 2615 if (curthread != NULL) 2616 td = curthread; 2617 else 2618 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 2619 /* 2620 * Since this only runs when rebooting, it is not interlocked. 2621 */ 2622 while(!TAILQ_EMPTY(&mountlist)) { 2623 mp = TAILQ_LAST(&mountlist, mntlist); 2624 error = dounmount(mp, MNT_FORCE, td); 2625 if (error) { 2626 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2627 printf("unmount of %s failed (", 2628 mp->mnt_stat.f_mntonname); 2629 if (error == EBUSY) 2630 printf("BUSY)\n"); 2631 else 2632 printf("%d)\n", error); 2633 } else { 2634 /* The unmount has removed mp from the mountlist */ 2635 } 2636 } 2637 } 2638 2639 /* 2640 * perform msync on all vnodes under a mount point 2641 * the mount point must be locked. 2642 */ 2643 void 2644 vfs_msync(struct mount *mp, int flags) 2645 { 2646 struct vnode *vp, *nvp; 2647 struct vm_object *obj; 2648 int tries; 2649 2650 GIANT_REQUIRED; 2651 2652 tries = 5; 2653 mtx_lock(&mntvnode_mtx); 2654 loop: 2655 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 2656 if (vp->v_mount != mp) { 2657 if (--tries > 0) 2658 goto loop; 2659 break; 2660 } 2661 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2662 2663 if (vp->v_flag & VXLOCK) /* XXX: what if MNT_WAIT? */ 2664 continue; 2665 2666 if (vp->v_flag & VNOSYNC) /* unlinked, skip it */ 2667 continue; 2668 2669 if ((vp->v_flag & VOBJDIRTY) && 2670 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2671 mtx_unlock(&mntvnode_mtx); 2672 if (!vget(vp, 2673 LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curthread)) { 2674 if (VOP_GETVOBJECT(vp, &obj) == 0) { 2675 vm_object_page_clean(obj, 0, 0, 2676 flags == MNT_WAIT ? 2677 OBJPC_SYNC : OBJPC_NOSYNC); 2678 } 2679 vput(vp); 2680 } 2681 mtx_lock(&mntvnode_mtx); 2682 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 2683 if (--tries > 0) 2684 goto loop; 2685 break; 2686 } 2687 } 2688 } 2689 mtx_unlock(&mntvnode_mtx); 2690 } 2691 2692 /* 2693 * Create the VM object needed for VMIO and mmap support. This 2694 * is done for all VREG files in the system. Some filesystems might 2695 * afford the additional metadata buffering capability of the 2696 * VMIO code by making the device node be VMIO mode also. 2697 * 2698 * vp must be locked when vfs_object_create is called. 2699 */ 2700 int 2701 vfs_object_create(vp, td, cred) 2702 struct vnode *vp; 2703 struct thread *td; 2704 struct ucred *cred; 2705 { 2706 GIANT_REQUIRED; 2707 return (VOP_CREATEVOBJECT(vp, cred, td)); 2708 } 2709 2710 /* 2711 * Mark a vnode as free, putting it up for recycling. 2712 */ 2713 void 2714 vfree(vp) 2715 struct vnode *vp; 2716 { 2717 int s; 2718 2719 s = splbio(); 2720 mtx_lock(&vnode_free_list_mtx); 2721 KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free")); 2722 if (vp->v_flag & VAGE) { 2723 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2724 } else { 2725 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 2726 } 2727 freevnodes++; 2728 mtx_unlock(&vnode_free_list_mtx); 2729 vp->v_flag &= ~VAGE; 2730 vp->v_flag |= VFREE; 2731 splx(s); 2732 } 2733 2734 /* 2735 * Opposite of vfree() - mark a vnode as in use. 2736 */ 2737 void 2738 vbusy(vp) 2739 struct vnode *vp; 2740 { 2741 int s; 2742 2743 s = splbio(); 2744 mtx_lock(&vnode_free_list_mtx); 2745 KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free")); 2746 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2747 freevnodes--; 2748 mtx_unlock(&vnode_free_list_mtx); 2749 vp->v_flag &= ~(VFREE|VAGE); 2750 splx(s); 2751 } 2752 2753 /* 2754 * Record a process's interest in events which might happen to 2755 * a vnode. Because poll uses the historic select-style interface 2756 * internally, this routine serves as both the ``check for any 2757 * pending events'' and the ``record my interest in future events'' 2758 * functions. (These are done together, while the lock is held, 2759 * to avoid race conditions.) 2760 */ 2761 int 2762 vn_pollrecord(vp, td, events) 2763 struct vnode *vp; 2764 struct thread *td; 2765 short events; 2766 { 2767 2768 if (vp->v_pollinfo == NULL) 2769 v_addpollinfo(vp); 2770 mtx_lock(&vp->v_pollinfo->vpi_lock); 2771 if (vp->v_pollinfo->vpi_revents & events) { 2772 /* 2773 * This leaves events we are not interested 2774 * in available for the other process which 2775 * which presumably had requested them 2776 * (otherwise they would never have been 2777 * recorded). 2778 */ 2779 events &= vp->v_pollinfo->vpi_revents; 2780 vp->v_pollinfo->vpi_revents &= ~events; 2781 2782 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2783 return events; 2784 } 2785 vp->v_pollinfo->vpi_events |= events; 2786 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 2787 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2788 return 0; 2789 } 2790 2791 /* 2792 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 2793 * it is possible for us to miss an event due to race conditions, but 2794 * that condition is expected to be rare, so for the moment it is the 2795 * preferred interface. 2796 */ 2797 void 2798 vn_pollevent(vp, events) 2799 struct vnode *vp; 2800 short events; 2801 { 2802 2803 if (vp->v_pollinfo == NULL) 2804 v_addpollinfo(vp); 2805 mtx_lock(&vp->v_pollinfo->vpi_lock); 2806 if (vp->v_pollinfo->vpi_events & events) { 2807 /* 2808 * We clear vpi_events so that we don't 2809 * call selwakeup() twice if two events are 2810 * posted before the polling process(es) is 2811 * awakened. This also ensures that we take at 2812 * most one selwakeup() if the polling process 2813 * is no longer interested. However, it does 2814 * mean that only one event can be noticed at 2815 * a time. (Perhaps we should only clear those 2816 * event bits which we note?) XXX 2817 */ 2818 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 2819 vp->v_pollinfo->vpi_revents |= events; 2820 selwakeup(&vp->v_pollinfo->vpi_selinfo); 2821 } 2822 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2823 } 2824 2825 /* 2826 * Wake up anyone polling on vp because it is being revoked. 2827 * This depends on dead_poll() returning POLLHUP for correct 2828 * behavior. 2829 */ 2830 void 2831 vn_pollgone(vp) 2832 struct vnode *vp; 2833 { 2834 2835 mtx_lock(&vp->v_pollinfo->vpi_lock); 2836 VN_KNOTE(vp, NOTE_REVOKE); 2837 if (vp->v_pollinfo->vpi_events) { 2838 vp->v_pollinfo->vpi_events = 0; 2839 selwakeup(&vp->v_pollinfo->vpi_selinfo); 2840 } 2841 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2842 } 2843 2844 2845 2846 /* 2847 * Routine to create and manage a filesystem syncer vnode. 2848 */ 2849 #define sync_close ((int (*)(struct vop_close_args *))nullop) 2850 static int sync_fsync(struct vop_fsync_args *); 2851 static int sync_inactive(struct vop_inactive_args *); 2852 static int sync_reclaim(struct vop_reclaim_args *); 2853 #define sync_lock ((int (*)(struct vop_lock_args *))vop_nolock) 2854 #define sync_unlock ((int (*)(struct vop_unlock_args *))vop_nounlock) 2855 static int sync_print(struct vop_print_args *); 2856 #define sync_islocked ((int(*)(struct vop_islocked_args *))vop_noislocked) 2857 2858 static vop_t **sync_vnodeop_p; 2859 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 2860 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 2861 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 2862 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 2863 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 2864 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 2865 { &vop_lock_desc, (vop_t *) sync_lock }, /* lock */ 2866 { &vop_unlock_desc, (vop_t *) sync_unlock }, /* unlock */ 2867 { &vop_print_desc, (vop_t *) sync_print }, /* print */ 2868 { &vop_islocked_desc, (vop_t *) sync_islocked }, /* islocked */ 2869 { NULL, NULL } 2870 }; 2871 static struct vnodeopv_desc sync_vnodeop_opv_desc = 2872 { &sync_vnodeop_p, sync_vnodeop_entries }; 2873 2874 VNODEOP_SET(sync_vnodeop_opv_desc); 2875 2876 /* 2877 * Create a new filesystem syncer vnode for the specified mount point. 2878 */ 2879 int 2880 vfs_allocate_syncvnode(mp) 2881 struct mount *mp; 2882 { 2883 struct vnode *vp; 2884 static long start, incr, next; 2885 int error; 2886 2887 /* Allocate a new vnode */ 2888 if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) { 2889 mp->mnt_syncer = NULL; 2890 return (error); 2891 } 2892 vp->v_type = VNON; 2893 /* 2894 * Place the vnode onto the syncer worklist. We attempt to 2895 * scatter them about on the list so that they will go off 2896 * at evenly distributed times even if all the filesystems 2897 * are mounted at once. 2898 */ 2899 next += incr; 2900 if (next == 0 || next > syncer_maxdelay) { 2901 start /= 2; 2902 incr /= 2; 2903 if (start == 0) { 2904 start = syncer_maxdelay / 2; 2905 incr = syncer_maxdelay; 2906 } 2907 next = start; 2908 } 2909 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 2910 mp->mnt_syncer = vp; 2911 return (0); 2912 } 2913 2914 /* 2915 * Do a lazy sync of the filesystem. 2916 */ 2917 static int 2918 sync_fsync(ap) 2919 struct vop_fsync_args /* { 2920 struct vnode *a_vp; 2921 struct ucred *a_cred; 2922 int a_waitfor; 2923 struct thread *a_td; 2924 } */ *ap; 2925 { 2926 struct vnode *syncvp = ap->a_vp; 2927 struct mount *mp = syncvp->v_mount; 2928 struct thread *td = ap->a_td; 2929 int asyncflag; 2930 2931 /* 2932 * We only need to do something if this is a lazy evaluation. 2933 */ 2934 if (ap->a_waitfor != MNT_LAZY) 2935 return (0); 2936 2937 /* 2938 * Move ourselves to the back of the sync list. 2939 */ 2940 vn_syncer_add_to_worklist(syncvp, syncdelay); 2941 2942 /* 2943 * Walk the list of vnodes pushing all that are dirty and 2944 * not already on the sync list. 2945 */ 2946 mtx_lock(&mountlist_mtx); 2947 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 2948 mtx_unlock(&mountlist_mtx); 2949 return (0); 2950 } 2951 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 2952 vfs_unbusy(mp, td); 2953 return (0); 2954 } 2955 asyncflag = mp->mnt_flag & MNT_ASYNC; 2956 mp->mnt_flag &= ~MNT_ASYNC; 2957 vfs_msync(mp, MNT_NOWAIT); 2958 VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 2959 if (asyncflag) 2960 mp->mnt_flag |= MNT_ASYNC; 2961 vn_finished_write(mp); 2962 vfs_unbusy(mp, td); 2963 return (0); 2964 } 2965 2966 /* 2967 * The syncer vnode is no referenced. 2968 */ 2969 static int 2970 sync_inactive(ap) 2971 struct vop_inactive_args /* { 2972 struct vnode *a_vp; 2973 struct thread *a_td; 2974 } */ *ap; 2975 { 2976 2977 vgone(ap->a_vp); 2978 return (0); 2979 } 2980 2981 /* 2982 * The syncer vnode is no longer needed and is being decommissioned. 2983 * 2984 * Modifications to the worklist must be protected at splbio(). 2985 */ 2986 static int 2987 sync_reclaim(ap) 2988 struct vop_reclaim_args /* { 2989 struct vnode *a_vp; 2990 } */ *ap; 2991 { 2992 struct vnode *vp = ap->a_vp; 2993 int s; 2994 2995 s = splbio(); 2996 vp->v_mount->mnt_syncer = NULL; 2997 if (vp->v_flag & VONWORKLST) { 2998 LIST_REMOVE(vp, v_synclist); 2999 vp->v_flag &= ~VONWORKLST; 3000 } 3001 splx(s); 3002 3003 return (0); 3004 } 3005 3006 /* 3007 * Print out a syncer vnode. 3008 */ 3009 static int 3010 sync_print(ap) 3011 struct vop_print_args /* { 3012 struct vnode *a_vp; 3013 } */ *ap; 3014 { 3015 struct vnode *vp = ap->a_vp; 3016 3017 printf("syncer vnode"); 3018 if (vp->v_vnlock != NULL) 3019 lockmgr_printinfo(vp->v_vnlock); 3020 printf("\n"); 3021 return (0); 3022 } 3023 3024 /* 3025 * extract the dev_t from a VCHR 3026 */ 3027 dev_t 3028 vn_todev(vp) 3029 struct vnode *vp; 3030 { 3031 if (vp->v_type != VCHR) 3032 return (NODEV); 3033 return (vp->v_rdev); 3034 } 3035 3036 /* 3037 * Check if vnode represents a disk device 3038 */ 3039 int 3040 vn_isdisk(vp, errp) 3041 struct vnode *vp; 3042 int *errp; 3043 { 3044 struct cdevsw *cdevsw; 3045 3046 if (vp->v_type != VCHR) { 3047 if (errp != NULL) 3048 *errp = ENOTBLK; 3049 return (0); 3050 } 3051 if (vp->v_rdev == NULL) { 3052 if (errp != NULL) 3053 *errp = ENXIO; 3054 return (0); 3055 } 3056 cdevsw = devsw(vp->v_rdev); 3057 if (cdevsw == NULL) { 3058 if (errp != NULL) 3059 *errp = ENXIO; 3060 return (0); 3061 } 3062 if (!(cdevsw->d_flags & D_DISK)) { 3063 if (errp != NULL) 3064 *errp = ENOTBLK; 3065 return (0); 3066 } 3067 if (errp != NULL) 3068 *errp = 0; 3069 return (1); 3070 } 3071 3072 /* 3073 * Free data allocated by namei(); see namei(9) for details. 3074 */ 3075 void 3076 NDFREE(ndp, flags) 3077 struct nameidata *ndp; 3078 const uint flags; 3079 { 3080 if (!(flags & NDF_NO_FREE_PNBUF) && 3081 (ndp->ni_cnd.cn_flags & HASBUF)) { 3082 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3083 ndp->ni_cnd.cn_flags &= ~HASBUF; 3084 } 3085 if (!(flags & NDF_NO_DVP_UNLOCK) && 3086 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3087 ndp->ni_dvp != ndp->ni_vp) 3088 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3089 if (!(flags & NDF_NO_DVP_RELE) && 3090 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3091 vrele(ndp->ni_dvp); 3092 ndp->ni_dvp = NULL; 3093 } 3094 if (!(flags & NDF_NO_VP_UNLOCK) && 3095 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3096 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3097 if (!(flags & NDF_NO_VP_RELE) && 3098 ndp->ni_vp) { 3099 vrele(ndp->ni_vp); 3100 ndp->ni_vp = NULL; 3101 } 3102 if (!(flags & NDF_NO_STARTDIR_RELE) && 3103 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3104 vrele(ndp->ni_startdir); 3105 ndp->ni_startdir = NULL; 3106 } 3107 } 3108 3109 /* 3110 * Common filesystem object access control check routine. Accepts a 3111 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3112 * and optional call-by-reference privused argument allowing vaccess() 3113 * to indicate to the caller whether privilege was used to satisfy the 3114 * request. Returns 0 on success, or an errno on failure. 3115 */ 3116 int 3117 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3118 enum vtype type; 3119 mode_t file_mode; 3120 uid_t file_uid; 3121 gid_t file_gid; 3122 mode_t acc_mode; 3123 struct ucred *cred; 3124 int *privused; 3125 { 3126 mode_t dac_granted; 3127 #ifdef CAPABILITIES 3128 mode_t cap_granted; 3129 #endif 3130 3131 /* 3132 * Look for a normal, non-privileged way to access the file/directory 3133 * as requested. If it exists, go with that. 3134 */ 3135 3136 if (privused != NULL) 3137 *privused = 0; 3138 3139 dac_granted = 0; 3140 3141 /* Check the owner. */ 3142 if (cred->cr_uid == file_uid) { 3143 dac_granted |= VADMIN; 3144 if (file_mode & S_IXUSR) 3145 dac_granted |= VEXEC; 3146 if (file_mode & S_IRUSR) 3147 dac_granted |= VREAD; 3148 if (file_mode & S_IWUSR) 3149 dac_granted |= VWRITE; 3150 3151 if ((acc_mode & dac_granted) == acc_mode) 3152 return (0); 3153 3154 goto privcheck; 3155 } 3156 3157 /* Otherwise, check the groups (first match) */ 3158 if (groupmember(file_gid, cred)) { 3159 if (file_mode & S_IXGRP) 3160 dac_granted |= VEXEC; 3161 if (file_mode & S_IRGRP) 3162 dac_granted |= VREAD; 3163 if (file_mode & S_IWGRP) 3164 dac_granted |= VWRITE; 3165 3166 if ((acc_mode & dac_granted) == acc_mode) 3167 return (0); 3168 3169 goto privcheck; 3170 } 3171 3172 /* Otherwise, check everyone else. */ 3173 if (file_mode & S_IXOTH) 3174 dac_granted |= VEXEC; 3175 if (file_mode & S_IROTH) 3176 dac_granted |= VREAD; 3177 if (file_mode & S_IWOTH) 3178 dac_granted |= VWRITE; 3179 if ((acc_mode & dac_granted) == acc_mode) 3180 return (0); 3181 3182 privcheck: 3183 if (!suser_cred(cred, PRISON_ROOT)) { 3184 /* XXX audit: privilege used */ 3185 if (privused != NULL) 3186 *privused = 1; 3187 return (0); 3188 } 3189 3190 #ifdef CAPABILITIES 3191 /* 3192 * Build a capability mask to determine if the set of capabilities 3193 * satisfies the requirements when combined with the granted mask 3194 * from above. 3195 * For each capability, if the capability is required, bitwise 3196 * or the request type onto the cap_granted mask. 3197 */ 3198 cap_granted = 0; 3199 3200 if (type == VDIR) { 3201 /* 3202 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3203 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3204 */ 3205 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3206 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3207 cap_granted |= VEXEC; 3208 } else { 3209 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3210 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3211 cap_granted |= VEXEC; 3212 } 3213 3214 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3215 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3216 cap_granted |= VREAD; 3217 3218 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3219 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3220 cap_granted |= VWRITE; 3221 3222 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3223 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3224 cap_granted |= VADMIN; 3225 3226 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3227 /* XXX audit: privilege used */ 3228 if (privused != NULL) 3229 *privused = 1; 3230 return (0); 3231 } 3232 #endif 3233 3234 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3235 } 3236