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/vmmeter.h> 63 #include <sys/vnode.h> 64 65 #include <vm/vm.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_extern.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 #include <vm/vm_page.h> 71 #include <vm/vm_zone.h> 72 73 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 74 75 static void addalias __P((struct vnode *vp, dev_t nvp_rdev)); 76 static void insmntque __P((struct vnode *vp, struct mount *mp)); 77 static void vclean __P((struct vnode *vp, int flags, struct thread *td)); 78 79 /* 80 * Number of vnodes in existence. Increased whenever getnewvnode() 81 * allocates a new vnode, never decreased. 82 */ 83 static unsigned long numvnodes; 84 SYSCTL_LONG(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 85 86 /* 87 * Conversion tables for conversion from vnode types to inode formats 88 * and back. 89 */ 90 enum vtype iftovt_tab[16] = { 91 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 92 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 93 }; 94 int vttoif_tab[9] = { 95 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 96 S_IFSOCK, S_IFIFO, S_IFMT, 97 }; 98 99 /* 100 * List of vnodes that are ready for recycling. 101 */ 102 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 103 104 /* 105 * Minimum number of free vnodes. If there are fewer than this free vnodes, 106 * getnewvnode() will return a newly allocated vnode. 107 */ 108 static u_long wantfreevnodes = 25; 109 SYSCTL_LONG(_debug, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 110 /* Number of vnodes in the free list. */ 111 static u_long freevnodes = 0; 112 SYSCTL_LONG(_debug, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 113 114 #if 0 115 /* Number of vnode allocation. */ 116 static u_long vnodeallocs = 0; 117 SYSCTL_LONG(_debug, OID_AUTO, vnodeallocs, CTLFLAG_RD, &vnodeallocs, 0, ""); 118 /* Period of vnode recycle from namecache in vnode allocation times. */ 119 static u_long vnoderecycleperiod = 1000; 120 SYSCTL_LONG(_debug, OID_AUTO, vnoderecycleperiod, CTLFLAG_RW, &vnoderecycleperiod, 0, ""); 121 /* Minimum number of total vnodes required to invoke vnode recycle from namecache. */ 122 static u_long vnoderecyclemintotalvn = 2000; 123 SYSCTL_LONG(_debug, OID_AUTO, vnoderecyclemintotalvn, CTLFLAG_RW, &vnoderecyclemintotalvn, 0, ""); 124 /* Minimum number of free vnodes required to invoke vnode recycle from namecache. */ 125 static u_long vnoderecycleminfreevn = 2000; 126 SYSCTL_LONG(_debug, OID_AUTO, vnoderecycleminfreevn, CTLFLAG_RW, &vnoderecycleminfreevn, 0, ""); 127 /* Number of vnodes attempted to recycle at a time. */ 128 static u_long vnoderecyclenumber = 3000; 129 SYSCTL_LONG(_debug, OID_AUTO, vnoderecyclenumber, CTLFLAG_RW, &vnoderecyclenumber, 0, ""); 130 #endif 131 132 /* 133 * Various variables used for debugging the new implementation of 134 * reassignbuf(). 135 * XXX these are probably of (very) limited utility now. 136 */ 137 static int reassignbufcalls; 138 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 139 static int reassignbufloops; 140 SYSCTL_INT(_vfs, OID_AUTO, reassignbufloops, CTLFLAG_RW, &reassignbufloops, 0, ""); 141 static int reassignbufsortgood; 142 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortgood, CTLFLAG_RW, &reassignbufsortgood, 0, ""); 143 static int reassignbufsortbad; 144 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad, 0, ""); 145 /* Set to 0 for old insertion-sort based reassignbuf, 1 for modern method. */ 146 static int reassignbufmethod = 1; 147 SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, ""); 148 static int nameileafonly = 0; 149 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 150 151 #ifdef ENABLE_VFS_IOOPT 152 /* See NOTES for a description of this setting. */ 153 int vfs_ioopt = 0; 154 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, ""); 155 #endif 156 157 /* List of mounted filesystems. */ 158 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 159 160 /* For any iteration/modification of mountlist */ 161 struct mtx mountlist_mtx; 162 163 /* For any iteration/modification of mnt_vnodelist */ 164 struct mtx mntvnode_mtx; 165 166 /* 167 * Cache for the mount type id assigned to NFS. This is used for 168 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 169 */ 170 int nfs_mount_type = -1; 171 172 /* To keep more than one thread at a time from running vfs_getnewfsid */ 173 static struct mtx mntid_mtx; 174 175 /* For any iteration/modification of vnode_free_list */ 176 static struct mtx vnode_free_list_mtx; 177 178 /* 179 * For any iteration/modification of dev->si_hlist (linked through 180 * v_specnext) 181 */ 182 static struct mtx spechash_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 vm_zone_t vnode_zone; 189 190 /* Set to 1 to print out reclaim of active vnodes */ 191 int prtactive = 0; 192 193 /* 194 * The workitem queue. 195 * 196 * It is useful to delay writes of file data and filesystem metadata 197 * for tens of seconds so that quickly created and deleted files need 198 * not waste disk bandwidth being created and removed. To realize this, 199 * we append vnodes to a "workitem" queue. When running with a soft 200 * updates implementation, most pending metadata dependencies should 201 * not wait for more than a few seconds. Thus, mounted on block devices 202 * are delayed only about a half the time that file data is delayed. 203 * Similarly, directory updates are more critical, so are only delayed 204 * about a third the time that file data is delayed. Thus, there are 205 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 206 * one each second (driven off the filesystem syncer process). The 207 * syncer_delayno variable indicates the next queue that is to be processed. 208 * Items that need to be processed soon are placed in this queue: 209 * 210 * syncer_workitem_pending[syncer_delayno] 211 * 212 * A delay of fifteen seconds is done by placing the request fifteen 213 * entries later in the queue: 214 * 215 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 216 * 217 */ 218 static int syncer_delayno = 0; 219 static long syncer_mask; 220 LIST_HEAD(synclist, vnode); 221 static struct synclist *syncer_workitem_pending; 222 223 #define SYNCER_MAXDELAY 32 224 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 225 static int syncdelay = 30; /* max time to delay syncing data */ 226 static int filedelay = 30; /* time to delay syncing files */ 227 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 228 static int dirdelay = 29; /* time to delay syncing directories */ 229 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 230 static int metadelay = 28; /* time to delay syncing metadata */ 231 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 232 static int rushjob; /* number of slots to run ASAP */ 233 static int stat_rush_requests; /* number of times I/O speeded up */ 234 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 235 236 /* 237 * Number of vnodes we want to exist at any one time. This is mostly used 238 * to size hash tables in vnode-related code. It is normally not used in 239 * getnewvnode(), as wantfreevnodes is normally nonzero.) 240 * 241 * XXX desiredvnodes is historical cruft and should not exist. 242 */ 243 int desiredvnodes; 244 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 245 &desiredvnodes, 0, "Maximum number of vnodes"); 246 static int minvnodes; 247 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 248 &minvnodes, 0, "Minimum number of vnodes"); 249 250 /* 251 * Initialize the vnode management data structures. 252 */ 253 static void 254 vntblinit(void *dummy __unused) 255 { 256 257 desiredvnodes = maxproc + cnt.v_page_count / 4; 258 minvnodes = desiredvnodes / 4; 259 mtx_init(&mountlist_mtx, "mountlist", MTX_DEF); 260 mtx_init(&mntvnode_mtx, "mntvnode", MTX_DEF); 261 mtx_init(&mntid_mtx, "mntid", MTX_DEF); 262 mtx_init(&spechash_mtx, "spechash", MTX_DEF); 263 TAILQ_INIT(&vnode_free_list); 264 mtx_init(&vnode_free_list_mtx, "vnode_free_list", MTX_DEF); 265 vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5); 266 /* 267 * Initialize the filesystem syncer. 268 */ 269 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 270 &syncer_mask); 271 syncer_maxdelay = syncer_mask + 1; 272 } 273 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 274 275 276 /* 277 * Mark a mount point as busy. Used to synchronize access and to delay 278 * unmounting. Interlock is not released on failure. 279 */ 280 int 281 vfs_busy(mp, flags, interlkp, td) 282 struct mount *mp; 283 int flags; 284 struct mtx *interlkp; 285 struct thread *td; 286 { 287 int lkflags; 288 289 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 290 if (flags & LK_NOWAIT) 291 return (ENOENT); 292 mp->mnt_kern_flag |= MNTK_MWAIT; 293 /* 294 * Since all busy locks are shared except the exclusive 295 * lock granted when unmounting, the only place that a 296 * wakeup needs to be done is at the release of the 297 * exclusive lock at the end of dounmount. 298 */ 299 msleep((caddr_t)mp, interlkp, PVFS, "vfs_busy", 0); 300 return (ENOENT); 301 } 302 lkflags = LK_SHARED | LK_NOPAUSE; 303 if (interlkp) 304 lkflags |= LK_INTERLOCK; 305 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 306 panic("vfs_busy: unexpected lock failure"); 307 return (0); 308 } 309 310 /* 311 * Free a busy filesystem. 312 */ 313 void 314 vfs_unbusy(mp, td) 315 struct mount *mp; 316 struct thread *td; 317 { 318 319 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 320 } 321 322 /* 323 * Lookup a filesystem type, and if found allocate and initialize 324 * a mount structure for it. 325 * 326 * Devname is usually updated by mount(8) after booting. 327 */ 328 int 329 vfs_rootmountalloc(fstypename, devname, mpp) 330 char *fstypename; 331 char *devname; 332 struct mount **mpp; 333 { 334 struct thread *td = curthread; /* XXX */ 335 struct vfsconf *vfsp; 336 struct mount *mp; 337 338 if (fstypename == NULL) 339 return (ENODEV); 340 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 341 if (!strcmp(vfsp->vfc_name, fstypename)) 342 break; 343 if (vfsp == NULL) 344 return (ENODEV); 345 mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 346 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 347 (void)vfs_busy(mp, LK_NOWAIT, 0, td); 348 TAILQ_INIT(&mp->mnt_nvnodelist); 349 TAILQ_INIT(&mp->mnt_reservedvnlist); 350 mp->mnt_vfc = vfsp; 351 mp->mnt_op = vfsp->vfc_vfsops; 352 mp->mnt_flag = MNT_RDONLY; 353 mp->mnt_vnodecovered = NULLVP; 354 vfsp->vfc_refcount++; 355 mp->mnt_iosize_max = DFLTPHYS; 356 mp->mnt_stat.f_type = vfsp->vfc_typenum; 357 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 358 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 359 mp->mnt_stat.f_mntonname[0] = '/'; 360 mp->mnt_stat.f_mntonname[1] = 0; 361 (void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0); 362 *mpp = mp; 363 return (0); 364 } 365 366 /* 367 * Find an appropriate filesystem to use for the root. If a filesystem 368 * has not been preselected, walk through the list of known filesystems 369 * trying those that have mountroot routines, and try them until one 370 * works or we have tried them all. 371 */ 372 #ifdef notdef /* XXX JH */ 373 int 374 lite2_vfs_mountroot() 375 { 376 struct vfsconf *vfsp; 377 extern int (*lite2_mountroot) __P((void)); 378 int error; 379 380 if (lite2_mountroot != NULL) 381 return ((*lite2_mountroot)()); 382 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 383 if (vfsp->vfc_mountroot == NULL) 384 continue; 385 if ((error = (*vfsp->vfc_mountroot)()) == 0) 386 return (0); 387 printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error); 388 } 389 return (ENODEV); 390 } 391 #endif 392 393 /* 394 * Lookup a mount point by filesystem identifier. 395 */ 396 struct mount * 397 vfs_getvfs(fsid) 398 fsid_t *fsid; 399 { 400 register struct mount *mp; 401 402 mtx_lock(&mountlist_mtx); 403 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 404 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 405 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 406 mtx_unlock(&mountlist_mtx); 407 return (mp); 408 } 409 } 410 mtx_unlock(&mountlist_mtx); 411 return ((struct mount *) 0); 412 } 413 414 /* 415 * Get a new unique fsid. Try to make its val[0] unique, since this value 416 * will be used to create fake device numbers for stat(). Also try (but 417 * not so hard) make its val[0] unique mod 2^16, since some emulators only 418 * support 16-bit device numbers. We end up with unique val[0]'s for the 419 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 420 * 421 * Keep in mind that several mounts may be running in parallel. Starting 422 * the search one past where the previous search terminated is both a 423 * micro-optimization and a defense against returning the same fsid to 424 * different mounts. 425 */ 426 void 427 vfs_getnewfsid(mp) 428 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] = makeudev(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(tsp) 469 struct timespec *tsp; 470 { 471 struct timeval tv; 472 473 switch (timestamp_precision) { 474 case TSP_SEC: 475 tsp->tv_sec = time_second; 476 tsp->tv_nsec = 0; 477 break; 478 case TSP_HZ: 479 getnanotime(tsp); 480 break; 481 case TSP_USEC: 482 microtime(&tv); 483 TIMEVAL_TO_TIMESPEC(&tv, tsp); 484 break; 485 case TSP_NSEC: 486 default: 487 nanotime(tsp); 488 break; 489 } 490 } 491 492 /* 493 * Set vnode attributes to VNOVAL 494 */ 495 void 496 vattr_null(vap) 497 register struct vattr *vap; 498 { 499 500 vap->va_type = VNON; 501 vap->va_size = VNOVAL; 502 vap->va_bytes = VNOVAL; 503 vap->va_mode = VNOVAL; 504 vap->va_nlink = VNOVAL; 505 vap->va_uid = VNOVAL; 506 vap->va_gid = VNOVAL; 507 vap->va_fsid = VNOVAL; 508 vap->va_fileid = VNOVAL; 509 vap->va_blocksize = VNOVAL; 510 vap->va_rdev = VNOVAL; 511 vap->va_atime.tv_sec = VNOVAL; 512 vap->va_atime.tv_nsec = VNOVAL; 513 vap->va_mtime.tv_sec = VNOVAL; 514 vap->va_mtime.tv_nsec = VNOVAL; 515 vap->va_ctime.tv_sec = VNOVAL; 516 vap->va_ctime.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 kernl.maxvnodes too low. 536 */ 537 static void 538 vlrureclaim(struct mount *mp, int count) 539 { 540 struct vnode *vp; 541 542 mtx_lock(&mntvnode_mtx); 543 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 544 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 545 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 546 547 if (vp->v_type != VNON && 548 vp->v_type != VBAD && 549 VMIGHTFREE(vp) && /* critical path opt */ 550 mtx_trylock(&vp->v_interlock) 551 ) { 552 mtx_unlock(&mntvnode_mtx); 553 if (VMIGHTFREE(vp)) { 554 vgonel(vp, curthread); 555 } else { 556 mtx_unlock(&vp->v_interlock); 557 } 558 mtx_lock(&mntvnode_mtx); 559 } 560 --count; 561 } 562 mtx_unlock(&mntvnode_mtx); 563 } 564 565 /* 566 * Routines having to do with the management of the vnode table. 567 */ 568 569 /* 570 * Return the next vnode from the free list. 571 */ 572 int 573 getnewvnode(tag, mp, vops, vpp) 574 enum vtagtype tag; 575 struct mount *mp; 576 vop_t **vops; 577 struct vnode **vpp; 578 { 579 int s; 580 struct thread *td = curthread; /* XXX */ 581 struct vnode *vp = NULL; 582 struct mount *vnmp; 583 vm_object_t object; 584 585 s = splbio(); 586 /* 587 * Try to reuse vnodes if we hit the max. This situation only 588 * occurs in certain large-memory (2G+) situations. For the 589 * algorithm to be stable we have to try to reuse at least 2. 590 * No hysteresis should be necessary. 591 */ 592 if (numvnodes - freevnodes > desiredvnodes) 593 vlrureclaim(mp, 2); 594 595 /* 596 * Attempt to reuse a vnode already on the free list, allocating 597 * a new vnode if we can't find one or if we have not reached a 598 * good minimum for good LRU performance. 599 */ 600 601 mtx_lock(&vnode_free_list_mtx); 602 603 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 604 int count; 605 606 for (count = 0; count < freevnodes; count++) { 607 vp = TAILQ_FIRST(&vnode_free_list); 608 if (vp == NULL || vp->v_usecount) 609 panic("getnewvnode: free vnode isn't"); 610 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 611 612 /* 613 * Don't recycle if we still have cached pages or if 614 * we cannot get the interlock. 615 */ 616 if ((VOP_GETVOBJECT(vp, &object) == 0 && 617 (object->resident_page_count || 618 object->ref_count)) || 619 !mtx_trylock(&vp->v_interlock)) { 620 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 621 v_freelist); 622 vp = NULL; 623 continue; 624 } 625 if (LIST_FIRST(&vp->v_cache_src)) { 626 /* 627 * note: nameileafonly sysctl is temporary, 628 * for debugging only, and will eventually be 629 * removed. 630 */ 631 if (nameileafonly > 0) { 632 /* 633 * Do not reuse namei-cached directory 634 * vnodes that have cached 635 * subdirectories. 636 */ 637 if (cache_leaf_test(vp) < 0) { 638 mtx_unlock(&vp->v_interlock); 639 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 640 vp = NULL; 641 continue; 642 } 643 } else if (nameileafonly < 0 || 644 vmiodirenable == 0) { 645 /* 646 * Do not reuse namei-cached directory 647 * vnodes if nameileafonly is -1 or 648 * if VMIO backing for directories is 649 * turned off (otherwise we reuse them 650 * too quickly). 651 */ 652 mtx_unlock(&vp->v_interlock); 653 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 654 vp = NULL; 655 continue; 656 } 657 } 658 /* 659 * Skip over it if its filesystem is being suspended. 660 */ 661 if (vn_start_write(vp, &vnmp, V_NOWAIT) == 0) 662 break; 663 mtx_unlock(&vp->v_interlock); 664 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 665 vp = NULL; 666 } 667 } 668 if (vp) { 669 vp->v_flag |= VDOOMED; 670 vp->v_flag &= ~VFREE; 671 freevnodes--; 672 mtx_unlock(&vnode_free_list_mtx); 673 cache_purge(vp); 674 vp->v_lease = NULL; 675 if (vp->v_type != VBAD) { 676 vgonel(vp, td); 677 } else { 678 mtx_unlock(&vp->v_interlock); 679 } 680 vn_finished_write(vnmp); 681 682 #ifdef INVARIANTS 683 { 684 int s; 685 686 if (vp->v_data) 687 panic("cleaned vnode isn't"); 688 s = splbio(); 689 if (vp->v_numoutput) 690 panic("Clean vnode has pending I/O's"); 691 splx(s); 692 if (vp->v_writecount != 0) 693 panic("Non-zero write count"); 694 } 695 #endif 696 vp->v_flag = 0; 697 vp->v_lastw = 0; 698 vp->v_lasta = 0; 699 vp->v_cstart = 0; 700 vp->v_clen = 0; 701 vp->v_socket = 0; 702 } else { 703 mtx_unlock(&vnode_free_list_mtx); 704 vp = (struct vnode *) zalloc(vnode_zone); 705 bzero((char *) vp, sizeof *vp); 706 mtx_init(&vp->v_interlock, "vnode interlock", MTX_DEF); 707 vp->v_dd = vp; 708 mtx_init(&vp->v_pollinfo.vpi_lock, "vnode pollinfo", MTX_DEF); 709 cache_purge(vp); 710 LIST_INIT(&vp->v_cache_src); 711 TAILQ_INIT(&vp->v_cache_dst); 712 numvnodes++; 713 } 714 715 TAILQ_INIT(&vp->v_cleanblkhd); 716 TAILQ_INIT(&vp->v_dirtyblkhd); 717 vp->v_type = VNON; 718 vp->v_tag = tag; 719 vp->v_op = vops; 720 lockinit(&vp->v_lock, PVFS, "vnlock", 0, LK_NOPAUSE); 721 insmntque(vp, mp); 722 *vpp = vp; 723 vp->v_usecount = 1; 724 vp->v_data = 0; 725 726 splx(s); 727 728 vfs_object_create(vp, td, td->td_proc->p_ucred); 729 730 #if 0 731 vnodeallocs++; 732 if (vnodeallocs % vnoderecycleperiod == 0 && 733 freevnodes < vnoderecycleminfreevn && 734 vnoderecyclemintotalvn < numvnodes) { 735 /* Recycle vnodes. */ 736 cache_purgeleafdirs(vnoderecyclenumber); 737 } 738 #endif 739 740 return (0); 741 } 742 743 /* 744 * Move a vnode from one mount queue to another. 745 */ 746 static void 747 insmntque(vp, mp) 748 register struct vnode *vp; 749 register struct mount *mp; 750 { 751 752 mtx_lock(&mntvnode_mtx); 753 /* 754 * Delete from old mount point vnode list, if on one. 755 */ 756 if (vp->v_mount != NULL) 757 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 758 /* 759 * Insert into list of vnodes for the new mount point, if available. 760 */ 761 if ((vp->v_mount = mp) == NULL) { 762 mtx_unlock(&mntvnode_mtx); 763 return; 764 } 765 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 766 mtx_unlock(&mntvnode_mtx); 767 } 768 769 /* 770 * Update outstanding I/O count and do wakeup if requested. 771 */ 772 void 773 vwakeup(bp) 774 register struct buf *bp; 775 { 776 register struct vnode *vp; 777 778 bp->b_flags &= ~B_WRITEINPROG; 779 if ((vp = bp->b_vp)) { 780 vp->v_numoutput--; 781 if (vp->v_numoutput < 0) 782 panic("vwakeup: neg numoutput"); 783 if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) { 784 vp->v_flag &= ~VBWAIT; 785 wakeup((caddr_t) &vp->v_numoutput); 786 } 787 } 788 } 789 790 /* 791 * Flush out and invalidate all buffers associated with a vnode. 792 * Called with the underlying object locked. 793 */ 794 int 795 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 796 register struct vnode *vp; 797 int flags; 798 struct ucred *cred; 799 struct thread *td; 800 int slpflag, slptimeo; 801 { 802 register struct buf *bp; 803 struct buf *nbp, *blist; 804 int s, error; 805 vm_object_t object; 806 807 GIANT_REQUIRED; 808 809 if (flags & V_SAVE) { 810 s = splbio(); 811 while (vp->v_numoutput) { 812 vp->v_flag |= VBWAIT; 813 error = tsleep((caddr_t)&vp->v_numoutput, 814 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 815 if (error) { 816 splx(s); 817 return (error); 818 } 819 } 820 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 821 splx(s); 822 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 823 return (error); 824 s = splbio(); 825 if (vp->v_numoutput > 0 || 826 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 827 panic("vinvalbuf: dirty bufs"); 828 } 829 splx(s); 830 } 831 s = splbio(); 832 for (;;) { 833 blist = TAILQ_FIRST(&vp->v_cleanblkhd); 834 if (!blist) 835 blist = TAILQ_FIRST(&vp->v_dirtyblkhd); 836 if (!blist) 837 break; 838 839 for (bp = blist; bp; bp = nbp) { 840 nbp = TAILQ_NEXT(bp, b_vnbufs); 841 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 842 error = BUF_TIMELOCK(bp, 843 LK_EXCLUSIVE | LK_SLEEPFAIL, 844 "vinvalbuf", slpflag, slptimeo); 845 if (error == ENOLCK) 846 break; 847 splx(s); 848 return (error); 849 } 850 /* 851 * XXX Since there are no node locks for NFS, I 852 * believe there is a slight chance that a delayed 853 * write will occur while sleeping just above, so 854 * check for it. Note that vfs_bio_awrite expects 855 * buffers to reside on a queue, while BUF_WRITE and 856 * brelse do not. 857 */ 858 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 859 (flags & V_SAVE)) { 860 861 if (bp->b_vp == vp) { 862 if (bp->b_flags & B_CLUSTEROK) { 863 BUF_UNLOCK(bp); 864 vfs_bio_awrite(bp); 865 } else { 866 bremfree(bp); 867 bp->b_flags |= B_ASYNC; 868 BUF_WRITE(bp); 869 } 870 } else { 871 bremfree(bp); 872 (void) BUF_WRITE(bp); 873 } 874 break; 875 } 876 bremfree(bp); 877 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 878 bp->b_flags &= ~B_ASYNC; 879 brelse(bp); 880 } 881 } 882 883 /* 884 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 885 * have write I/O in-progress but if there is a VM object then the 886 * VM object can also have read-I/O in-progress. 887 */ 888 do { 889 while (vp->v_numoutput > 0) { 890 vp->v_flag |= VBWAIT; 891 tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0); 892 } 893 if (VOP_GETVOBJECT(vp, &object) == 0) { 894 while (object->paging_in_progress) 895 vm_object_pip_sleep(object, "vnvlbx"); 896 } 897 } while (vp->v_numoutput > 0); 898 899 splx(s); 900 901 /* 902 * Destroy the copy in the VM cache, too. 903 */ 904 mtx_lock(&vp->v_interlock); 905 if (VOP_GETVOBJECT(vp, &object) == 0) { 906 vm_object_page_remove(object, 0, 0, 907 (flags & V_SAVE) ? TRUE : FALSE); 908 } 909 mtx_unlock(&vp->v_interlock); 910 911 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd)) 912 panic("vinvalbuf: flush failed"); 913 return (0); 914 } 915 916 /* 917 * Truncate a file's buffer and pages to a specified length. This 918 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 919 * sync activity. 920 */ 921 int 922 vtruncbuf(vp, cred, td, length, blksize) 923 register struct vnode *vp; 924 struct ucred *cred; 925 struct thread *td; 926 off_t length; 927 int blksize; 928 { 929 register struct buf *bp; 930 struct buf *nbp; 931 int s, anyfreed; 932 int trunclbn; 933 934 /* 935 * Round up to the *next* lbn. 936 */ 937 trunclbn = (length + blksize - 1) / blksize; 938 939 s = splbio(); 940 restart: 941 anyfreed = 1; 942 for (;anyfreed;) { 943 anyfreed = 0; 944 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 945 nbp = TAILQ_NEXT(bp, b_vnbufs); 946 if (bp->b_lblkno >= trunclbn) { 947 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 948 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 949 goto restart; 950 } else { 951 bremfree(bp); 952 bp->b_flags |= (B_INVAL | B_RELBUF); 953 bp->b_flags &= ~B_ASYNC; 954 brelse(bp); 955 anyfreed = 1; 956 } 957 if (nbp && 958 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 959 (nbp->b_vp != vp) || 960 (nbp->b_flags & B_DELWRI))) { 961 goto restart; 962 } 963 } 964 } 965 966 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 967 nbp = TAILQ_NEXT(bp, b_vnbufs); 968 if (bp->b_lblkno >= trunclbn) { 969 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 970 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 971 goto restart; 972 } else { 973 bremfree(bp); 974 bp->b_flags |= (B_INVAL | B_RELBUF); 975 bp->b_flags &= ~B_ASYNC; 976 brelse(bp); 977 anyfreed = 1; 978 } 979 if (nbp && 980 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 981 (nbp->b_vp != vp) || 982 (nbp->b_flags & B_DELWRI) == 0)) { 983 goto restart; 984 } 985 } 986 } 987 } 988 989 if (length > 0) { 990 restartsync: 991 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 992 nbp = TAILQ_NEXT(bp, b_vnbufs); 993 if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { 994 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 995 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 996 goto restart; 997 } else { 998 bremfree(bp); 999 if (bp->b_vp == vp) { 1000 bp->b_flags |= B_ASYNC; 1001 } else { 1002 bp->b_flags &= ~B_ASYNC; 1003 } 1004 BUF_WRITE(bp); 1005 } 1006 goto restartsync; 1007 } 1008 1009 } 1010 } 1011 1012 while (vp->v_numoutput > 0) { 1013 vp->v_flag |= VBWAIT; 1014 tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0); 1015 } 1016 1017 splx(s); 1018 1019 vnode_pager_setsize(vp, length); 1020 1021 return (0); 1022 } 1023 1024 /* 1025 * Associate a buffer with a vnode. 1026 */ 1027 void 1028 bgetvp(vp, bp) 1029 register struct vnode *vp; 1030 register struct buf *bp; 1031 { 1032 int s; 1033 1034 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1035 1036 vhold(vp); 1037 bp->b_vp = vp; 1038 bp->b_dev = vn_todev(vp); 1039 /* 1040 * Insert onto list for new vnode. 1041 */ 1042 s = splbio(); 1043 bp->b_xflags |= BX_VNCLEAN; 1044 bp->b_xflags &= ~BX_VNDIRTY; 1045 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1046 splx(s); 1047 } 1048 1049 /* 1050 * Disassociate a buffer from a vnode. 1051 */ 1052 void 1053 brelvp(bp) 1054 register struct buf *bp; 1055 { 1056 struct vnode *vp; 1057 struct buflists *listheadp; 1058 int s; 1059 1060 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1061 1062 /* 1063 * Delete from old vnode list, if on one. 1064 */ 1065 vp = bp->b_vp; 1066 s = splbio(); 1067 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1068 if (bp->b_xflags & BX_VNDIRTY) 1069 listheadp = &vp->v_dirtyblkhd; 1070 else 1071 listheadp = &vp->v_cleanblkhd; 1072 TAILQ_REMOVE(listheadp, bp, b_vnbufs); 1073 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1074 } 1075 if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1076 vp->v_flag &= ~VONWORKLST; 1077 LIST_REMOVE(vp, v_synclist); 1078 } 1079 splx(s); 1080 bp->b_vp = (struct vnode *) 0; 1081 vdrop(vp); 1082 } 1083 1084 /* 1085 * Add an item to the syncer work queue. 1086 */ 1087 static void 1088 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1089 { 1090 int s, slot; 1091 1092 s = splbio(); 1093 1094 if (vp->v_flag & VONWORKLST) { 1095 LIST_REMOVE(vp, v_synclist); 1096 } 1097 1098 if (delay > syncer_maxdelay - 2) 1099 delay = syncer_maxdelay - 2; 1100 slot = (syncer_delayno + delay) & syncer_mask; 1101 1102 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1103 vp->v_flag |= VONWORKLST; 1104 splx(s); 1105 } 1106 1107 struct proc *updateproc; 1108 static void sched_sync __P((void)); 1109 static struct kproc_desc up_kp = { 1110 "syncer", 1111 sched_sync, 1112 &updateproc 1113 }; 1114 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1115 1116 /* 1117 * System filesystem synchronizer daemon. 1118 */ 1119 void 1120 sched_sync(void) 1121 { 1122 struct synclist *slp; 1123 struct vnode *vp; 1124 struct mount *mp; 1125 long starttime; 1126 int s; 1127 struct thread *td = &updateproc->p_thread; /* XXXKSE */ 1128 1129 mtx_lock(&Giant); 1130 1131 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1132 SHUTDOWN_PRI_LAST); 1133 1134 for (;;) { 1135 kthread_suspend_check(td->td_proc); 1136 1137 starttime = time_second; 1138 1139 /* 1140 * Push files whose dirty time has expired. Be careful 1141 * of interrupt race on slp queue. 1142 */ 1143 s = splbio(); 1144 slp = &syncer_workitem_pending[syncer_delayno]; 1145 syncer_delayno += 1; 1146 if (syncer_delayno == syncer_maxdelay) 1147 syncer_delayno = 0; 1148 splx(s); 1149 1150 while ((vp = LIST_FIRST(slp)) != NULL) { 1151 if (VOP_ISLOCKED(vp, NULL) == 0 && 1152 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1153 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1154 (void) VOP_FSYNC(vp, td->td_proc->p_ucred, MNT_LAZY, td); 1155 VOP_UNLOCK(vp, 0, td); 1156 vn_finished_write(mp); 1157 } 1158 s = splbio(); 1159 if (LIST_FIRST(slp) == vp) { 1160 /* 1161 * Note: v_tag VT_VFS vps can remain on the 1162 * worklist too with no dirty blocks, but 1163 * since sync_fsync() moves it to a different 1164 * slot we are safe. 1165 */ 1166 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1167 !vn_isdisk(vp, NULL)) 1168 panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag); 1169 /* 1170 * Put us back on the worklist. The worklist 1171 * routine will remove us from our current 1172 * position and then add us back in at a later 1173 * position. 1174 */ 1175 vn_syncer_add_to_worklist(vp, syncdelay); 1176 } 1177 splx(s); 1178 } 1179 1180 /* 1181 * Do soft update processing. 1182 */ 1183 #ifdef SOFTUPDATES 1184 softdep_process_worklist(NULL); 1185 #endif 1186 1187 /* 1188 * The variable rushjob allows the kernel to speed up the 1189 * processing of the filesystem syncer process. A rushjob 1190 * value of N tells the filesystem syncer to process the next 1191 * N seconds worth of work on its queue ASAP. Currently rushjob 1192 * is used by the soft update code to speed up the filesystem 1193 * syncer process when the incore state is getting so far 1194 * ahead of the disk that the kernel memory pool is being 1195 * threatened with exhaustion. 1196 */ 1197 if (rushjob > 0) { 1198 rushjob -= 1; 1199 continue; 1200 } 1201 /* 1202 * If it has taken us less than a second to process the 1203 * current work, then wait. Otherwise start right over 1204 * again. We can still lose time if any single round 1205 * takes more than two seconds, but it does not really 1206 * matter as we are just trying to generally pace the 1207 * filesystem activity. 1208 */ 1209 if (time_second == starttime) 1210 tsleep(&lbolt, PPAUSE, "syncer", 0); 1211 } 1212 } 1213 1214 /* 1215 * Request the syncer daemon to speed up its work. 1216 * We never push it to speed up more than half of its 1217 * normal turn time, otherwise it could take over the cpu. 1218 * XXXKSE only one update? 1219 */ 1220 int 1221 speedup_syncer() 1222 { 1223 1224 mtx_lock_spin(&sched_lock); 1225 if (updateproc->p_thread.td_wchan == &lbolt) /* XXXKSE */ 1226 setrunnable(&updateproc->p_thread); 1227 mtx_unlock_spin(&sched_lock); 1228 if (rushjob < syncdelay / 2) { 1229 rushjob += 1; 1230 stat_rush_requests += 1; 1231 return (1); 1232 } 1233 return(0); 1234 } 1235 1236 /* 1237 * Associate a p-buffer with a vnode. 1238 * 1239 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1240 * with the buffer. i.e. the bp has not been linked into the vnode or 1241 * ref-counted. 1242 */ 1243 void 1244 pbgetvp(vp, bp) 1245 register struct vnode *vp; 1246 register struct buf *bp; 1247 { 1248 1249 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1250 1251 bp->b_vp = vp; 1252 bp->b_flags |= B_PAGING; 1253 bp->b_dev = vn_todev(vp); 1254 } 1255 1256 /* 1257 * Disassociate a p-buffer from a vnode. 1258 */ 1259 void 1260 pbrelvp(bp) 1261 register struct buf *bp; 1262 { 1263 1264 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1265 1266 /* XXX REMOVE ME */ 1267 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1268 panic( 1269 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1270 bp, 1271 (int)bp->b_flags 1272 ); 1273 } 1274 bp->b_vp = (struct vnode *) 0; 1275 bp->b_flags &= ~B_PAGING; 1276 } 1277 1278 /* 1279 * Change the vnode a pager buffer is associated with. 1280 */ 1281 void 1282 pbreassignbuf(bp, newvp) 1283 struct buf *bp; 1284 struct vnode *newvp; 1285 { 1286 1287 KASSERT(bp->b_flags & B_PAGING, 1288 ("pbreassignbuf() on non phys bp %p", bp)); 1289 bp->b_vp = newvp; 1290 } 1291 1292 /* 1293 * Reassign a buffer from one vnode to another. 1294 * Used to assign file specific control information 1295 * (indirect blocks) to the vnode to which they belong. 1296 */ 1297 void 1298 reassignbuf(bp, newvp) 1299 register struct buf *bp; 1300 register struct vnode *newvp; 1301 { 1302 struct buflists *listheadp; 1303 int delay; 1304 int s; 1305 1306 if (newvp == NULL) { 1307 printf("reassignbuf: NULL"); 1308 return; 1309 } 1310 ++reassignbufcalls; 1311 1312 /* 1313 * B_PAGING flagged buffers cannot be reassigned because their vp 1314 * is not fully linked in. 1315 */ 1316 if (bp->b_flags & B_PAGING) 1317 panic("cannot reassign paging buffer"); 1318 1319 s = splbio(); 1320 /* 1321 * Delete from old vnode list, if on one. 1322 */ 1323 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1324 if (bp->b_xflags & BX_VNDIRTY) 1325 listheadp = &bp->b_vp->v_dirtyblkhd; 1326 else 1327 listheadp = &bp->b_vp->v_cleanblkhd; 1328 TAILQ_REMOVE(listheadp, bp, b_vnbufs); 1329 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1330 if (bp->b_vp != newvp) { 1331 vdrop(bp->b_vp); 1332 bp->b_vp = NULL; /* for clarification */ 1333 } 1334 } 1335 /* 1336 * If dirty, put on list of dirty buffers; otherwise insert onto list 1337 * of clean buffers. 1338 */ 1339 if (bp->b_flags & B_DELWRI) { 1340 struct buf *tbp; 1341 1342 listheadp = &newvp->v_dirtyblkhd; 1343 if ((newvp->v_flag & VONWORKLST) == 0) { 1344 switch (newvp->v_type) { 1345 case VDIR: 1346 delay = dirdelay; 1347 break; 1348 case VCHR: 1349 if (newvp->v_rdev->si_mountpoint != NULL) { 1350 delay = metadelay; 1351 break; 1352 } 1353 /* fall through */ 1354 default: 1355 delay = filedelay; 1356 } 1357 vn_syncer_add_to_worklist(newvp, delay); 1358 } 1359 bp->b_xflags |= BX_VNDIRTY; 1360 tbp = TAILQ_FIRST(listheadp); 1361 if (tbp == NULL || 1362 bp->b_lblkno == 0 || 1363 (bp->b_lblkno > 0 && tbp->b_lblkno < 0) || 1364 (bp->b_lblkno > 0 && bp->b_lblkno < tbp->b_lblkno)) { 1365 TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs); 1366 ++reassignbufsortgood; 1367 } else if (bp->b_lblkno < 0) { 1368 TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs); 1369 ++reassignbufsortgood; 1370 } else if (reassignbufmethod == 1) { 1371 /* 1372 * New sorting algorithm, only handle sequential case, 1373 * otherwise append to end (but before metadata) 1374 */ 1375 if ((tbp = gbincore(newvp, bp->b_lblkno - 1)) != NULL && 1376 (tbp->b_xflags & BX_VNDIRTY)) { 1377 /* 1378 * Found the best place to insert the buffer 1379 */ 1380 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1381 ++reassignbufsortgood; 1382 } else { 1383 /* 1384 * Missed, append to end, but before meta-data. 1385 * We know that the head buffer in the list is 1386 * not meta-data due to prior conditionals. 1387 * 1388 * Indirect effects: NFS second stage write 1389 * tends to wind up here, giving maximum 1390 * distance between the unstable write and the 1391 * commit rpc. 1392 */ 1393 tbp = TAILQ_LAST(listheadp, buflists); 1394 while (tbp && tbp->b_lblkno < 0) 1395 tbp = TAILQ_PREV(tbp, buflists, b_vnbufs); 1396 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1397 ++reassignbufsortbad; 1398 } 1399 } else { 1400 /* 1401 * Old sorting algorithm, scan queue and insert 1402 */ 1403 struct buf *ttbp; 1404 while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) && 1405 (ttbp->b_lblkno < bp->b_lblkno)) { 1406 ++reassignbufloops; 1407 tbp = ttbp; 1408 } 1409 TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); 1410 } 1411 } else { 1412 bp->b_xflags |= BX_VNCLEAN; 1413 TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs); 1414 if ((newvp->v_flag & VONWORKLST) && 1415 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1416 newvp->v_flag &= ~VONWORKLST; 1417 LIST_REMOVE(newvp, v_synclist); 1418 } 1419 } 1420 if (bp->b_vp != newvp) { 1421 bp->b_vp = newvp; 1422 vhold(bp->b_vp); 1423 } 1424 splx(s); 1425 } 1426 1427 /* 1428 * Create a vnode for a device. 1429 * Used for mounting the root file system. 1430 */ 1431 int 1432 bdevvp(dev, vpp) 1433 dev_t dev; 1434 struct vnode **vpp; 1435 { 1436 register struct vnode *vp; 1437 struct vnode *nvp; 1438 int error; 1439 1440 if (dev == NODEV) { 1441 *vpp = NULLVP; 1442 return (ENXIO); 1443 } 1444 if (vfinddev(dev, VCHR, vpp)) 1445 return (0); 1446 error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp); 1447 if (error) { 1448 *vpp = NULLVP; 1449 return (error); 1450 } 1451 vp = nvp; 1452 vp->v_type = VCHR; 1453 addalias(vp, dev); 1454 *vpp = vp; 1455 return (0); 1456 } 1457 1458 /* 1459 * Add vnode to the alias list hung off the dev_t. 1460 * 1461 * The reason for this gunk is that multiple vnodes can reference 1462 * the same physical device, so checking vp->v_usecount to see 1463 * how many users there are is inadequate; the v_usecount for 1464 * the vnodes need to be accumulated. vcount() does that. 1465 */ 1466 struct vnode * 1467 addaliasu(nvp, nvp_rdev) 1468 struct vnode *nvp; 1469 udev_t nvp_rdev; 1470 { 1471 struct vnode *ovp; 1472 vop_t **ops; 1473 dev_t dev; 1474 1475 if (nvp->v_type == VBLK) 1476 return (nvp); 1477 if (nvp->v_type != VCHR) 1478 panic("addaliasu on non-special vnode"); 1479 dev = udev2dev(nvp_rdev, 0); 1480 /* 1481 * Check to see if we have a bdevvp vnode with no associated 1482 * filesystem. If so, we want to associate the filesystem of 1483 * the new newly instigated vnode with the bdevvp vnode and 1484 * discard the newly created vnode rather than leaving the 1485 * bdevvp vnode lying around with no associated filesystem. 1486 */ 1487 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 1488 addalias(nvp, dev); 1489 return (nvp); 1490 } 1491 /* 1492 * Discard unneeded vnode, but save its node specific data. 1493 * Note that if there is a lock, it is carried over in the 1494 * node specific data to the replacement vnode. 1495 */ 1496 vref(ovp); 1497 ovp->v_data = nvp->v_data; 1498 ovp->v_tag = nvp->v_tag; 1499 nvp->v_data = NULL; 1500 lockinit(&ovp->v_lock, PVFS, nvp->v_lock.lk_wmesg, 1501 nvp->v_lock.lk_timo, nvp->v_lock.lk_flags & LK_EXTFLG_MASK); 1502 if (nvp->v_vnlock) 1503 ovp->v_vnlock = &ovp->v_lock; 1504 ops = ovp->v_op; 1505 ovp->v_op = nvp->v_op; 1506 if (VOP_ISLOCKED(nvp, curthread)) { 1507 VOP_UNLOCK(nvp, 0, curthread); 1508 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1509 } 1510 nvp->v_op = ops; 1511 insmntque(ovp, nvp->v_mount); 1512 vrele(nvp); 1513 vgone(nvp); 1514 return (ovp); 1515 } 1516 1517 /* This is a local helper function that do the same as addaliasu, but for a 1518 * dev_t instead of an udev_t. */ 1519 static void 1520 addalias(nvp, dev) 1521 struct vnode *nvp; 1522 dev_t dev; 1523 { 1524 1525 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1526 nvp->v_rdev = dev; 1527 mtx_lock(&spechash_mtx); 1528 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1529 mtx_unlock(&spechash_mtx); 1530 } 1531 1532 /* 1533 * Grab a particular vnode from the free list, increment its 1534 * reference count and lock it. The vnode lock bit is set if the 1535 * vnode is being eliminated in vgone. The process is awakened 1536 * when the transition is completed, and an error returned to 1537 * indicate that the vnode is no longer usable (possibly having 1538 * been changed to a new file system type). 1539 */ 1540 int 1541 vget(vp, flags, td) 1542 register struct vnode *vp; 1543 int flags; 1544 struct thread *td; 1545 { 1546 int error; 1547 1548 /* 1549 * If the vnode is in the process of being cleaned out for 1550 * another use, we wait for the cleaning to finish and then 1551 * return failure. Cleaning is determined by checking that 1552 * the VXLOCK flag is set. 1553 */ 1554 if ((flags & LK_INTERLOCK) == 0) 1555 mtx_lock(&vp->v_interlock); 1556 if (vp->v_flag & VXLOCK) { 1557 if (vp->v_vxproc == curthread) { 1558 printf("VXLOCK interlock avoided\n"); 1559 } else { 1560 vp->v_flag |= VXWANT; 1561 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 1562 "vget", 0); 1563 return (ENOENT); 1564 } 1565 } 1566 1567 vp->v_usecount++; 1568 1569 if (VSHOULDBUSY(vp)) 1570 vbusy(vp); 1571 if (flags & LK_TYPE_MASK) { 1572 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1573 /* 1574 * must expand vrele here because we do not want 1575 * to call VOP_INACTIVE if the reference count 1576 * drops back to zero since it was never really 1577 * active. We must remove it from the free list 1578 * before sleeping so that multiple processes do 1579 * not try to recycle it. 1580 */ 1581 mtx_lock(&vp->v_interlock); 1582 vp->v_usecount--; 1583 if (VSHOULDFREE(vp)) 1584 vfree(vp); 1585 mtx_unlock(&vp->v_interlock); 1586 } 1587 return (error); 1588 } 1589 mtx_unlock(&vp->v_interlock); 1590 return (0); 1591 } 1592 1593 /* 1594 * Increase the reference count of a vnode. 1595 */ 1596 void 1597 vref(struct vnode *vp) 1598 { 1599 mtx_lock(&vp->v_interlock); 1600 vp->v_usecount++; 1601 mtx_unlock(&vp->v_interlock); 1602 } 1603 1604 /* 1605 * Vnode put/release. 1606 * If count drops to zero, call inactive routine and return to freelist. 1607 */ 1608 void 1609 vrele(vp) 1610 struct vnode *vp; 1611 { 1612 struct thread *td = curthread; /* XXX */ 1613 1614 KASSERT(vp != NULL, ("vrele: null vp")); 1615 1616 mtx_lock(&vp->v_interlock); 1617 1618 /* Skip this v_writecount check if we're going to panic below. */ 1619 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1620 ("vrele: missed vn_close")); 1621 1622 if (vp->v_usecount > 1) { 1623 1624 vp->v_usecount--; 1625 mtx_unlock(&vp->v_interlock); 1626 1627 return; 1628 } 1629 1630 if (vp->v_usecount == 1) { 1631 vp->v_usecount--; 1632 if (VSHOULDFREE(vp)) 1633 vfree(vp); 1634 /* 1635 * If we are doing a vput, the node is already locked, and we must 1636 * call VOP_INACTIVE with the node locked. So, in the case of 1637 * vrele, we explicitly lock the vnode before calling VOP_INACTIVE. 1638 */ 1639 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { 1640 VOP_INACTIVE(vp, td); 1641 } 1642 1643 } else { 1644 #ifdef DIAGNOSTIC 1645 vprint("vrele: negative ref count", vp); 1646 mtx_unlock(&vp->v_interlock); 1647 #endif 1648 panic("vrele: negative ref cnt"); 1649 } 1650 } 1651 1652 /* 1653 * Release an already locked vnode. This give the same effects as 1654 * unlock+vrele(), but takes less time and avoids releasing and 1655 * re-aquiring the lock (as vrele() aquires the lock internally.) 1656 */ 1657 void 1658 vput(vp) 1659 struct vnode *vp; 1660 { 1661 struct thread *td = curthread; /* XXX */ 1662 1663 GIANT_REQUIRED; 1664 1665 KASSERT(vp != NULL, ("vput: null vp")); 1666 mtx_lock(&vp->v_interlock); 1667 /* Skip this v_writecount check if we're going to panic below. */ 1668 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1669 ("vput: missed vn_close")); 1670 1671 if (vp->v_usecount > 1) { 1672 vp->v_usecount--; 1673 VOP_UNLOCK(vp, LK_INTERLOCK, td); 1674 return; 1675 } 1676 1677 if (vp->v_usecount == 1) { 1678 vp->v_usecount--; 1679 if (VSHOULDFREE(vp)) 1680 vfree(vp); 1681 /* 1682 * If we are doing a vput, the node is already locked, and we must 1683 * call VOP_INACTIVE with the node locked. So, in the case of 1684 * vrele, we explicitly lock the vnode before calling VOP_INACTIVE. 1685 */ 1686 mtx_unlock(&vp->v_interlock); 1687 VOP_INACTIVE(vp, td); 1688 1689 } else { 1690 #ifdef DIAGNOSTIC 1691 vprint("vput: negative ref count", vp); 1692 #endif 1693 panic("vput: negative ref cnt"); 1694 } 1695 } 1696 1697 /* 1698 * Somebody doesn't want the vnode recycled. 1699 */ 1700 void 1701 vhold(vp) 1702 register struct vnode *vp; 1703 { 1704 int s; 1705 1706 s = splbio(); 1707 vp->v_holdcnt++; 1708 if (VSHOULDBUSY(vp)) 1709 vbusy(vp); 1710 splx(s); 1711 } 1712 1713 /* 1714 * Note that there is one less who cares about this vnode. vdrop() is the 1715 * opposite of vhold(). 1716 */ 1717 void 1718 vdrop(vp) 1719 register struct vnode *vp; 1720 { 1721 int s; 1722 1723 s = splbio(); 1724 if (vp->v_holdcnt <= 0) 1725 panic("vdrop: holdcnt"); 1726 vp->v_holdcnt--; 1727 if (VSHOULDFREE(vp)) 1728 vfree(vp); 1729 splx(s); 1730 } 1731 1732 /* 1733 * Remove any vnodes in the vnode table belonging to mount point mp. 1734 * 1735 * If FORCECLOSE is not specified, there should not be any active ones, 1736 * return error if any are found (nb: this is a user error, not a 1737 * system error). If FORCECLOSE is specified, detach any active vnodes 1738 * that are found. 1739 * 1740 * If WRITECLOSE is set, only flush out regular file vnodes open for 1741 * writing. 1742 * 1743 * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped. 1744 * 1745 * `rootrefs' specifies the base reference count for the root vnode 1746 * of this filesystem. The root vnode is considered busy if its 1747 * v_usecount exceeds this value. On a successful return, vflush() 1748 * will call vrele() on the root vnode exactly rootrefs times. 1749 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 1750 * be zero. 1751 */ 1752 #ifdef DIAGNOSTIC 1753 static int busyprt = 0; /* print out busy vnodes */ 1754 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 1755 #endif 1756 1757 int 1758 vflush(mp, rootrefs, flags) 1759 struct mount *mp; 1760 int rootrefs; 1761 int flags; 1762 { 1763 struct thread *td = curthread; /* XXX */ 1764 struct vnode *vp, *nvp, *rootvp = NULL; 1765 int busy = 0, error; 1766 1767 if (rootrefs > 0) { 1768 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 1769 ("vflush: bad args")); 1770 /* 1771 * Get the filesystem root vnode. We can vput() it 1772 * immediately, since with rootrefs > 0, it won't go away. 1773 */ 1774 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 1775 return (error); 1776 vput(rootvp); 1777 } 1778 mtx_lock(&mntvnode_mtx); 1779 loop: 1780 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 1781 /* 1782 * Make sure this vnode wasn't reclaimed in getnewvnode(). 1783 * Start over if it has (it won't be on the list anymore). 1784 */ 1785 if (vp->v_mount != mp) 1786 goto loop; 1787 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1788 1789 mtx_unlock(&mntvnode_mtx); 1790 mtx_lock(&vp->v_interlock); 1791 /* 1792 * Skip over a vnodes marked VSYSTEM. 1793 */ 1794 if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) { 1795 mtx_unlock(&vp->v_interlock); 1796 mtx_lock(&mntvnode_mtx); 1797 continue; 1798 } 1799 /* 1800 * If WRITECLOSE is set, only flush out regular file vnodes 1801 * open for writing. 1802 */ 1803 if ((flags & WRITECLOSE) && 1804 (vp->v_writecount == 0 || vp->v_type != VREG)) { 1805 mtx_unlock(&vp->v_interlock); 1806 mtx_lock(&mntvnode_mtx); 1807 continue; 1808 } 1809 1810 /* 1811 * With v_usecount == 0, all we need to do is clear out the 1812 * vnode data structures and we are done. 1813 */ 1814 if (vp->v_usecount == 0) { 1815 vgonel(vp, td); 1816 mtx_lock(&mntvnode_mtx); 1817 continue; 1818 } 1819 1820 /* 1821 * If FORCECLOSE is set, forcibly close the vnode. For block 1822 * or character devices, revert to an anonymous device. For 1823 * all other files, just kill them. 1824 */ 1825 if (flags & FORCECLOSE) { 1826 if (vp->v_type != VCHR) { 1827 vgonel(vp, td); 1828 } else { 1829 vclean(vp, 0, td); 1830 vp->v_op = spec_vnodeop_p; 1831 insmntque(vp, (struct mount *) 0); 1832 } 1833 mtx_lock(&mntvnode_mtx); 1834 continue; 1835 } 1836 #ifdef DIAGNOSTIC 1837 if (busyprt) 1838 vprint("vflush: busy vnode", vp); 1839 #endif 1840 mtx_unlock(&vp->v_interlock); 1841 mtx_lock(&mntvnode_mtx); 1842 busy++; 1843 } 1844 mtx_unlock(&mntvnode_mtx); 1845 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 1846 /* 1847 * If just the root vnode is busy, and if its refcount 1848 * is equal to `rootrefs', then go ahead and kill it. 1849 */ 1850 mtx_lock(&rootvp->v_interlock); 1851 KASSERT(busy > 0, ("vflush: not busy")); 1852 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 1853 if (busy == 1 && rootvp->v_usecount == rootrefs) { 1854 vgonel(rootvp, td); 1855 busy = 0; 1856 } else 1857 mtx_unlock(&rootvp->v_interlock); 1858 } 1859 if (busy) 1860 return (EBUSY); 1861 for (; rootrefs > 0; rootrefs--) 1862 vrele(rootvp); 1863 return (0); 1864 } 1865 1866 /* 1867 * Disassociate the underlying file system from a vnode. 1868 */ 1869 static void 1870 vclean(vp, flags, td) 1871 struct vnode *vp; 1872 int flags; 1873 struct thread *td; 1874 { 1875 int active; 1876 1877 /* 1878 * Check to see if the vnode is in use. If so we have to reference it 1879 * before we clean it out so that its count cannot fall to zero and 1880 * generate a race against ourselves to recycle it. 1881 */ 1882 if ((active = vp->v_usecount)) 1883 vp->v_usecount++; 1884 1885 /* 1886 * Prevent the vnode from being recycled or brought into use while we 1887 * clean it out. 1888 */ 1889 if (vp->v_flag & VXLOCK) 1890 panic("vclean: deadlock"); 1891 vp->v_flag |= VXLOCK; 1892 vp->v_vxproc = curthread; 1893 /* 1894 * Even if the count is zero, the VOP_INACTIVE routine may still 1895 * have the object locked while it cleans it out. The VOP_LOCK 1896 * ensures that the VOP_INACTIVE routine is done with its work. 1897 * For active vnodes, it ensures that no other activity can 1898 * occur while the underlying object is being cleaned out. 1899 */ 1900 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 1901 1902 /* 1903 * Clean out any buffers associated with the vnode. 1904 * If the flush fails, just toss the buffers. 1905 */ 1906 if (flags & DOCLOSE) { 1907 if (TAILQ_FIRST(&vp->v_dirtyblkhd) != NULL) 1908 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 1909 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 1910 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 1911 } 1912 1913 VOP_DESTROYVOBJECT(vp); 1914 1915 /* 1916 * If purging an active vnode, it must be closed and 1917 * deactivated before being reclaimed. Note that the 1918 * VOP_INACTIVE will unlock the vnode. 1919 */ 1920 if (active) { 1921 if (flags & DOCLOSE) 1922 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 1923 VOP_INACTIVE(vp, td); 1924 } else { 1925 /* 1926 * Any other processes trying to obtain this lock must first 1927 * wait for VXLOCK to clear, then call the new lock operation. 1928 */ 1929 VOP_UNLOCK(vp, 0, td); 1930 } 1931 /* 1932 * Reclaim the vnode. 1933 */ 1934 if (VOP_RECLAIM(vp, td)) 1935 panic("vclean: cannot reclaim"); 1936 1937 if (active) { 1938 /* 1939 * Inline copy of vrele() since VOP_INACTIVE 1940 * has already been called. 1941 */ 1942 mtx_lock(&vp->v_interlock); 1943 if (--vp->v_usecount <= 0) { 1944 #ifdef DIAGNOSTIC 1945 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 1946 vprint("vclean: bad ref count", vp); 1947 panic("vclean: ref cnt"); 1948 } 1949 #endif 1950 vfree(vp); 1951 } 1952 mtx_unlock(&vp->v_interlock); 1953 } 1954 1955 cache_purge(vp); 1956 vp->v_vnlock = NULL; 1957 lockdestroy(&vp->v_lock); 1958 1959 if (VSHOULDFREE(vp)) 1960 vfree(vp); 1961 1962 /* 1963 * Done with purge, notify sleepers of the grim news. 1964 */ 1965 vp->v_op = dead_vnodeop_p; 1966 vn_pollgone(vp); 1967 vp->v_tag = VT_NON; 1968 vp->v_flag &= ~VXLOCK; 1969 vp->v_vxproc = NULL; 1970 if (vp->v_flag & VXWANT) { 1971 vp->v_flag &= ~VXWANT; 1972 wakeup((caddr_t) vp); 1973 } 1974 } 1975 1976 /* 1977 * Eliminate all activity associated with the requested vnode 1978 * and with all vnodes aliased to the requested vnode. 1979 */ 1980 int 1981 vop_revoke(ap) 1982 struct vop_revoke_args /* { 1983 struct vnode *a_vp; 1984 int a_flags; 1985 } */ *ap; 1986 { 1987 struct vnode *vp, *vq; 1988 dev_t dev; 1989 1990 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 1991 1992 vp = ap->a_vp; 1993 /* 1994 * If a vgone (or vclean) is already in progress, 1995 * wait until it is done and return. 1996 */ 1997 if (vp->v_flag & VXLOCK) { 1998 vp->v_flag |= VXWANT; 1999 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 2000 "vop_revokeall", 0); 2001 return (0); 2002 } 2003 dev = vp->v_rdev; 2004 for (;;) { 2005 mtx_lock(&spechash_mtx); 2006 vq = SLIST_FIRST(&dev->si_hlist); 2007 mtx_unlock(&spechash_mtx); 2008 if (!vq) 2009 break; 2010 vgone(vq); 2011 } 2012 return (0); 2013 } 2014 2015 /* 2016 * Recycle an unused vnode to the front of the free list. 2017 * Release the passed interlock if the vnode will be recycled. 2018 */ 2019 int 2020 vrecycle(vp, inter_lkp, td) 2021 struct vnode *vp; 2022 struct mtx *inter_lkp; 2023 struct thread *td; 2024 { 2025 2026 mtx_lock(&vp->v_interlock); 2027 if (vp->v_usecount == 0) { 2028 if (inter_lkp) { 2029 mtx_unlock(inter_lkp); 2030 } 2031 vgonel(vp, td); 2032 return (1); 2033 } 2034 mtx_unlock(&vp->v_interlock); 2035 return (0); 2036 } 2037 2038 /* 2039 * Eliminate all activity associated with a vnode 2040 * in preparation for reuse. 2041 */ 2042 void 2043 vgone(vp) 2044 register struct vnode *vp; 2045 { 2046 struct thread *td = curthread; /* XXX */ 2047 2048 mtx_lock(&vp->v_interlock); 2049 vgonel(vp, td); 2050 } 2051 2052 /* 2053 * vgone, with the vp interlock held. 2054 */ 2055 void 2056 vgonel(vp, td) 2057 struct vnode *vp; 2058 struct thread *td; 2059 { 2060 int s; 2061 2062 /* 2063 * If a vgone (or vclean) is already in progress, 2064 * wait until it is done and return. 2065 */ 2066 if (vp->v_flag & VXLOCK) { 2067 vp->v_flag |= VXWANT; 2068 msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP, 2069 "vgone", 0); 2070 return; 2071 } 2072 2073 /* 2074 * Clean out the filesystem specific data. 2075 */ 2076 vclean(vp, DOCLOSE, td); 2077 mtx_lock(&vp->v_interlock); 2078 2079 /* 2080 * Delete from old mount point vnode list, if on one. 2081 */ 2082 if (vp->v_mount != NULL) 2083 insmntque(vp, (struct mount *)0); 2084 /* 2085 * If special device, remove it from special device alias list 2086 * if it is on one. 2087 */ 2088 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2089 mtx_lock(&spechash_mtx); 2090 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2091 freedev(vp->v_rdev); 2092 mtx_unlock(&spechash_mtx); 2093 vp->v_rdev = NULL; 2094 } 2095 2096 /* 2097 * If it is on the freelist and not already at the head, 2098 * move it to the head of the list. The test of the 2099 * VDOOMED flag and the reference count of zero is because 2100 * it will be removed from the free list by getnewvnode, 2101 * but will not have its reference count incremented until 2102 * after calling vgone. If the reference count were 2103 * incremented first, vgone would (incorrectly) try to 2104 * close the previous instance of the underlying object. 2105 */ 2106 if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) { 2107 s = splbio(); 2108 mtx_lock(&vnode_free_list_mtx); 2109 if (vp->v_flag & VFREE) 2110 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2111 else 2112 freevnodes++; 2113 vp->v_flag |= VFREE; 2114 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2115 mtx_unlock(&vnode_free_list_mtx); 2116 splx(s); 2117 } 2118 2119 vp->v_type = VBAD; 2120 mtx_unlock(&vp->v_interlock); 2121 } 2122 2123 /* 2124 * Lookup a vnode by device number. 2125 */ 2126 int 2127 vfinddev(dev, type, vpp) 2128 dev_t dev; 2129 enum vtype type; 2130 struct vnode **vpp; 2131 { 2132 struct vnode *vp; 2133 2134 mtx_lock(&spechash_mtx); 2135 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2136 if (type == vp->v_type) { 2137 *vpp = vp; 2138 mtx_unlock(&spechash_mtx); 2139 return (1); 2140 } 2141 } 2142 mtx_unlock(&spechash_mtx); 2143 return (0); 2144 } 2145 2146 /* 2147 * Calculate the total number of references to a special device. 2148 */ 2149 int 2150 vcount(vp) 2151 struct vnode *vp; 2152 { 2153 struct vnode *vq; 2154 int count; 2155 2156 count = 0; 2157 mtx_lock(&spechash_mtx); 2158 SLIST_FOREACH(vq, &vp->v_rdev->si_hlist, v_specnext) 2159 count += vq->v_usecount; 2160 mtx_unlock(&spechash_mtx); 2161 return (count); 2162 } 2163 2164 /* 2165 * Same as above, but using the dev_t as argument 2166 */ 2167 int 2168 count_dev(dev) 2169 dev_t dev; 2170 { 2171 struct vnode *vp; 2172 2173 vp = SLIST_FIRST(&dev->si_hlist); 2174 if (vp == NULL) 2175 return (0); 2176 return(vcount(vp)); 2177 } 2178 2179 /* 2180 * Print out a description of a vnode. 2181 */ 2182 static char *typename[] = 2183 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2184 2185 void 2186 vprint(label, vp) 2187 char *label; 2188 struct vnode *vp; 2189 { 2190 char buf[96]; 2191 2192 if (label != NULL) 2193 printf("%s: %p: ", label, (void *)vp); 2194 else 2195 printf("%p: ", (void *)vp); 2196 printf("type %s, usecount %d, writecount %d, refcount %d,", 2197 typename[vp->v_type], vp->v_usecount, vp->v_writecount, 2198 vp->v_holdcnt); 2199 buf[0] = '\0'; 2200 if (vp->v_flag & VROOT) 2201 strcat(buf, "|VROOT"); 2202 if (vp->v_flag & VTEXT) 2203 strcat(buf, "|VTEXT"); 2204 if (vp->v_flag & VSYSTEM) 2205 strcat(buf, "|VSYSTEM"); 2206 if (vp->v_flag & VXLOCK) 2207 strcat(buf, "|VXLOCK"); 2208 if (vp->v_flag & VXWANT) 2209 strcat(buf, "|VXWANT"); 2210 if (vp->v_flag & VBWAIT) 2211 strcat(buf, "|VBWAIT"); 2212 if (vp->v_flag & VDOOMED) 2213 strcat(buf, "|VDOOMED"); 2214 if (vp->v_flag & VFREE) 2215 strcat(buf, "|VFREE"); 2216 if (vp->v_flag & VOBJBUF) 2217 strcat(buf, "|VOBJBUF"); 2218 if (buf[0] != '\0') 2219 printf(" flags (%s)", &buf[1]); 2220 if (vp->v_data == NULL) { 2221 printf("\n"); 2222 } else { 2223 printf("\n\t"); 2224 VOP_PRINT(vp); 2225 } 2226 } 2227 2228 #ifdef DDB 2229 #include <ddb/ddb.h> 2230 /* 2231 * List all of the locked vnodes in the system. 2232 * Called when debugging the kernel. 2233 */ 2234 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes) 2235 { 2236 struct thread *td = curthread; /* XXX */ 2237 struct mount *mp, *nmp; 2238 struct vnode *vp; 2239 2240 printf("Locked vnodes\n"); 2241 mtx_lock(&mountlist_mtx); 2242 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2243 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2244 nmp = TAILQ_NEXT(mp, mnt_list); 2245 continue; 2246 } 2247 mtx_lock(&mntvnode_mtx); 2248 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2249 if (VOP_ISLOCKED(vp, NULL)) 2250 vprint((char *)0, vp); 2251 } 2252 mtx_unlock(&mntvnode_mtx); 2253 mtx_lock(&mountlist_mtx); 2254 nmp = TAILQ_NEXT(mp, mnt_list); 2255 vfs_unbusy(mp, td); 2256 } 2257 mtx_unlock(&mountlist_mtx); 2258 } 2259 #endif 2260 2261 /* 2262 * Top level filesystem related information gathering. 2263 */ 2264 static int sysctl_ovfs_conf __P((SYSCTL_HANDLER_ARGS)); 2265 2266 static int 2267 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2268 { 2269 int *name = (int *)arg1 - 1; /* XXX */ 2270 u_int namelen = arg2 + 1; /* XXX */ 2271 struct vfsconf *vfsp; 2272 2273 #if 1 || defined(COMPAT_PRELITE2) 2274 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2275 if (namelen == 1) 2276 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2277 #endif 2278 2279 /* XXX the below code does not compile; vfs_sysctl does not exist. */ 2280 #ifdef notyet 2281 /* all sysctl names at this level are at least name and field */ 2282 if (namelen < 2) 2283 return (ENOTDIR); /* overloaded */ 2284 if (name[0] != VFS_GENERIC) { 2285 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2286 if (vfsp->vfc_typenum == name[0]) 2287 break; 2288 if (vfsp == NULL) 2289 return (EOPNOTSUPP); 2290 return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1, 2291 oldp, oldlenp, newp, newlen, td)); 2292 } 2293 #endif 2294 switch (name[1]) { 2295 case VFS_MAXTYPENUM: 2296 if (namelen != 2) 2297 return (ENOTDIR); 2298 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2299 case VFS_CONF: 2300 if (namelen != 3) 2301 return (ENOTDIR); /* overloaded */ 2302 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2303 if (vfsp->vfc_typenum == name[2]) 2304 break; 2305 if (vfsp == NULL) 2306 return (EOPNOTSUPP); 2307 return (SYSCTL_OUT(req, vfsp, sizeof *vfsp)); 2308 } 2309 return (EOPNOTSUPP); 2310 } 2311 2312 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl, 2313 "Generic filesystem"); 2314 2315 #if 1 || defined(COMPAT_PRELITE2) 2316 2317 static int 2318 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2319 { 2320 int error; 2321 struct vfsconf *vfsp; 2322 struct ovfsconf ovfs; 2323 2324 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 2325 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2326 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2327 ovfs.vfc_index = vfsp->vfc_typenum; 2328 ovfs.vfc_refcount = vfsp->vfc_refcount; 2329 ovfs.vfc_flags = vfsp->vfc_flags; 2330 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2331 if (error) 2332 return error; 2333 } 2334 return 0; 2335 } 2336 2337 #endif /* 1 || COMPAT_PRELITE2 */ 2338 2339 #if COMPILING_LINT 2340 #define KINFO_VNODESLOP 10 2341 /* 2342 * Dump vnode list (via sysctl). 2343 * Copyout address of vnode followed by vnode. 2344 */ 2345 /* ARGSUSED */ 2346 static int 2347 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2348 { 2349 struct thread *td = curthread; /* XXX */ 2350 struct mount *mp, *nmp; 2351 struct vnode *nvp, *vp; 2352 int error; 2353 2354 #define VPTRSZ sizeof (struct vnode *) 2355 #define VNODESZ sizeof (struct vnode) 2356 2357 req->lock = 0; 2358 if (!req->oldptr) /* Make an estimate */ 2359 return (SYSCTL_OUT(req, 0, 2360 (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ))); 2361 2362 mtx_lock(&mountlist_mtx); 2363 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2364 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2365 nmp = TAILQ_NEXT(mp, mnt_list); 2366 continue; 2367 } 2368 mtx_lock(&mntvnode_mtx); 2369 again: 2370 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2371 vp != NULL; 2372 vp = nvp) { 2373 /* 2374 * Check that the vp is still associated with 2375 * this filesystem. RACE: could have been 2376 * recycled onto the same filesystem. 2377 */ 2378 if (vp->v_mount != mp) 2379 goto again; 2380 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2381 mtx_unlock(&mntvnode_mtx); 2382 if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) || 2383 (error = SYSCTL_OUT(req, vp, VNODESZ))) 2384 return (error); 2385 mtx_lock(&mntvnode_mtx); 2386 } 2387 mtx_unlock(&mntvnode_mtx); 2388 mtx_lock(&mountlist_mtx); 2389 nmp = TAILQ_NEXT(mp, mnt_list); 2390 vfs_unbusy(mp, td); 2391 } 2392 mtx_unlock(&mountlist_mtx); 2393 2394 return (0); 2395 } 2396 2397 /* 2398 * XXX 2399 * Exporting the vnode list on large systems causes them to crash. 2400 * Exporting the vnode list on medium systems causes sysctl to coredump. 2401 */ 2402 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2403 0, 0, sysctl_vnode, "S,vnode", ""); 2404 #endif 2405 2406 /* 2407 * Check to see if a filesystem is mounted on a block device. 2408 */ 2409 int 2410 vfs_mountedon(vp) 2411 struct vnode *vp; 2412 { 2413 2414 if (vp->v_rdev->si_mountpoint != NULL) 2415 return (EBUSY); 2416 return (0); 2417 } 2418 2419 /* 2420 * Unmount all filesystems. The list is traversed in reverse order 2421 * of mounting to avoid dependencies. 2422 */ 2423 void 2424 vfs_unmountall() 2425 { 2426 struct mount *mp; 2427 struct thread *td; 2428 int error; 2429 2430 if (curthread != NULL) 2431 td = curthread; 2432 else 2433 td = &initproc->p_thread; /* XXX XXX should this be proc0? */ 2434 /* 2435 * Since this only runs when rebooting, it is not interlocked. 2436 */ 2437 while(!TAILQ_EMPTY(&mountlist)) { 2438 mp = TAILQ_LAST(&mountlist, mntlist); 2439 error = dounmount(mp, MNT_FORCE, td); 2440 if (error) { 2441 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2442 printf("unmount of %s failed (", 2443 mp->mnt_stat.f_mntonname); 2444 if (error == EBUSY) 2445 printf("BUSY)\n"); 2446 else 2447 printf("%d)\n", error); 2448 } else { 2449 /* The unmount has removed mp from the mountlist */ 2450 } 2451 } 2452 } 2453 2454 /* 2455 * perform msync on all vnodes under a mount point 2456 * the mount point must be locked. 2457 */ 2458 void 2459 vfs_msync(struct mount *mp, int flags) 2460 { 2461 struct vnode *vp, *nvp; 2462 struct vm_object *obj; 2463 int tries; 2464 2465 GIANT_REQUIRED; 2466 2467 tries = 5; 2468 mtx_lock(&mntvnode_mtx); 2469 loop: 2470 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 2471 if (vp->v_mount != mp) { 2472 if (--tries > 0) 2473 goto loop; 2474 break; 2475 } 2476 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2477 2478 if (vp->v_flag & VXLOCK) /* XXX: what if MNT_WAIT? */ 2479 continue; 2480 2481 if (vp->v_flag & VNOSYNC) /* unlinked, skip it */ 2482 continue; 2483 2484 if ((vp->v_flag & VOBJDIRTY) && 2485 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2486 mtx_unlock(&mntvnode_mtx); 2487 if (!vget(vp, 2488 LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curthread)) { 2489 if (VOP_GETVOBJECT(vp, &obj) == 0) { 2490 vm_object_page_clean(obj, 0, 0, 2491 flags == MNT_WAIT ? 2492 OBJPC_SYNC : OBJPC_NOSYNC); 2493 } 2494 vput(vp); 2495 } 2496 mtx_lock(&mntvnode_mtx); 2497 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 2498 if (--tries > 0) 2499 goto loop; 2500 break; 2501 } 2502 } 2503 } 2504 mtx_unlock(&mntvnode_mtx); 2505 } 2506 2507 /* 2508 * Create the VM object needed for VMIO and mmap support. This 2509 * is done for all VREG files in the system. Some filesystems might 2510 * afford the additional metadata buffering capability of the 2511 * VMIO code by making the device node be VMIO mode also. 2512 * 2513 * vp must be locked when vfs_object_create is called. 2514 */ 2515 int 2516 vfs_object_create(vp, td, cred) 2517 struct vnode *vp; 2518 struct thread *td; 2519 struct ucred *cred; 2520 { 2521 GIANT_REQUIRED; 2522 return (VOP_CREATEVOBJECT(vp, cred, td)); 2523 } 2524 2525 /* 2526 * Mark a vnode as free, putting it up for recycling. 2527 */ 2528 void 2529 vfree(vp) 2530 struct vnode *vp; 2531 { 2532 int s; 2533 2534 s = splbio(); 2535 mtx_lock(&vnode_free_list_mtx); 2536 KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free")); 2537 if (vp->v_flag & VAGE) { 2538 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2539 } else { 2540 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 2541 } 2542 freevnodes++; 2543 mtx_unlock(&vnode_free_list_mtx); 2544 vp->v_flag &= ~VAGE; 2545 vp->v_flag |= VFREE; 2546 splx(s); 2547 } 2548 2549 /* 2550 * Opposite of vfree() - mark a vnode as in use. 2551 */ 2552 void 2553 vbusy(vp) 2554 struct vnode *vp; 2555 { 2556 int s; 2557 2558 s = splbio(); 2559 mtx_lock(&vnode_free_list_mtx); 2560 KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free")); 2561 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2562 freevnodes--; 2563 mtx_unlock(&vnode_free_list_mtx); 2564 vp->v_flag &= ~(VFREE|VAGE); 2565 splx(s); 2566 } 2567 2568 /* 2569 * Record a process's interest in events which might happen to 2570 * a vnode. Because poll uses the historic select-style interface 2571 * internally, this routine serves as both the ``check for any 2572 * pending events'' and the ``record my interest in future events'' 2573 * functions. (These are done together, while the lock is held, 2574 * to avoid race conditions.) 2575 */ 2576 int 2577 vn_pollrecord(vp, td, events) 2578 struct vnode *vp; 2579 struct thread *td; 2580 short events; 2581 { 2582 mtx_lock(&vp->v_pollinfo.vpi_lock); 2583 if (vp->v_pollinfo.vpi_revents & events) { 2584 /* 2585 * This leaves events we are not interested 2586 * in available for the other process which 2587 * which presumably had requested them 2588 * (otherwise they would never have been 2589 * recorded). 2590 */ 2591 events &= vp->v_pollinfo.vpi_revents; 2592 vp->v_pollinfo.vpi_revents &= ~events; 2593 2594 mtx_unlock(&vp->v_pollinfo.vpi_lock); 2595 return events; 2596 } 2597 vp->v_pollinfo.vpi_events |= events; 2598 selrecord(td, &vp->v_pollinfo.vpi_selinfo); 2599 mtx_unlock(&vp->v_pollinfo.vpi_lock); 2600 return 0; 2601 } 2602 2603 /* 2604 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 2605 * it is possible for us to miss an event due to race conditions, but 2606 * that condition is expected to be rare, so for the moment it is the 2607 * preferred interface. 2608 */ 2609 void 2610 vn_pollevent(vp, events) 2611 struct vnode *vp; 2612 short events; 2613 { 2614 mtx_lock(&vp->v_pollinfo.vpi_lock); 2615 if (vp->v_pollinfo.vpi_events & events) { 2616 /* 2617 * We clear vpi_events so that we don't 2618 * call selwakeup() twice if two events are 2619 * posted before the polling process(es) is 2620 * awakened. This also ensures that we take at 2621 * most one selwakeup() if the polling process 2622 * is no longer interested. However, it does 2623 * mean that only one event can be noticed at 2624 * a time. (Perhaps we should only clear those 2625 * event bits which we note?) XXX 2626 */ 2627 vp->v_pollinfo.vpi_events = 0; /* &= ~events ??? */ 2628 vp->v_pollinfo.vpi_revents |= events; 2629 selwakeup(&vp->v_pollinfo.vpi_selinfo); 2630 } 2631 mtx_unlock(&vp->v_pollinfo.vpi_lock); 2632 } 2633 2634 #define VN_KNOTE(vp, b) \ 2635 KNOTE((struct klist *)&vp->v_pollinfo.vpi_selinfo.si_note, (b)) 2636 2637 /* 2638 * Wake up anyone polling on vp because it is being revoked. 2639 * This depends on dead_poll() returning POLLHUP for correct 2640 * behavior. 2641 */ 2642 void 2643 vn_pollgone(vp) 2644 struct vnode *vp; 2645 { 2646 mtx_lock(&vp->v_pollinfo.vpi_lock); 2647 VN_KNOTE(vp, NOTE_REVOKE); 2648 if (vp->v_pollinfo.vpi_events) { 2649 vp->v_pollinfo.vpi_events = 0; 2650 selwakeup(&vp->v_pollinfo.vpi_selinfo); 2651 } 2652 mtx_unlock(&vp->v_pollinfo.vpi_lock); 2653 } 2654 2655 2656 2657 /* 2658 * Routine to create and manage a filesystem syncer vnode. 2659 */ 2660 #define sync_close ((int (*) __P((struct vop_close_args *)))nullop) 2661 static int sync_fsync __P((struct vop_fsync_args *)); 2662 static int sync_inactive __P((struct vop_inactive_args *)); 2663 static int sync_reclaim __P((struct vop_reclaim_args *)); 2664 #define sync_lock ((int (*) __P((struct vop_lock_args *)))vop_nolock) 2665 #define sync_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock) 2666 static int sync_print __P((struct vop_print_args *)); 2667 #define sync_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked) 2668 2669 static vop_t **sync_vnodeop_p; 2670 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 2671 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 2672 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 2673 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 2674 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 2675 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 2676 { &vop_lock_desc, (vop_t *) sync_lock }, /* lock */ 2677 { &vop_unlock_desc, (vop_t *) sync_unlock }, /* unlock */ 2678 { &vop_print_desc, (vop_t *) sync_print }, /* print */ 2679 { &vop_islocked_desc, (vop_t *) sync_islocked }, /* islocked */ 2680 { NULL, NULL } 2681 }; 2682 static struct vnodeopv_desc sync_vnodeop_opv_desc = 2683 { &sync_vnodeop_p, sync_vnodeop_entries }; 2684 2685 VNODEOP_SET(sync_vnodeop_opv_desc); 2686 2687 /* 2688 * Create a new filesystem syncer vnode for the specified mount point. 2689 */ 2690 int 2691 vfs_allocate_syncvnode(mp) 2692 struct mount *mp; 2693 { 2694 struct vnode *vp; 2695 static long start, incr, next; 2696 int error; 2697 2698 /* Allocate a new vnode */ 2699 if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) { 2700 mp->mnt_syncer = NULL; 2701 return (error); 2702 } 2703 vp->v_type = VNON; 2704 /* 2705 * Place the vnode onto the syncer worklist. We attempt to 2706 * scatter them about on the list so that they will go off 2707 * at evenly distributed times even if all the filesystems 2708 * are mounted at once. 2709 */ 2710 next += incr; 2711 if (next == 0 || next > syncer_maxdelay) { 2712 start /= 2; 2713 incr /= 2; 2714 if (start == 0) { 2715 start = syncer_maxdelay / 2; 2716 incr = syncer_maxdelay; 2717 } 2718 next = start; 2719 } 2720 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 2721 mp->mnt_syncer = vp; 2722 return (0); 2723 } 2724 2725 /* 2726 * Do a lazy sync of the filesystem. 2727 */ 2728 static int 2729 sync_fsync(ap) 2730 struct vop_fsync_args /* { 2731 struct vnode *a_vp; 2732 struct ucred *a_cred; 2733 int a_waitfor; 2734 struct thread *a_td; 2735 } */ *ap; 2736 { 2737 struct vnode *syncvp = ap->a_vp; 2738 struct mount *mp = syncvp->v_mount; 2739 struct thread *td = ap->a_td; 2740 int asyncflag; 2741 2742 /* 2743 * We only need to do something if this is a lazy evaluation. 2744 */ 2745 if (ap->a_waitfor != MNT_LAZY) 2746 return (0); 2747 2748 /* 2749 * Move ourselves to the back of the sync list. 2750 */ 2751 vn_syncer_add_to_worklist(syncvp, syncdelay); 2752 2753 /* 2754 * Walk the list of vnodes pushing all that are dirty and 2755 * not already on the sync list. 2756 */ 2757 mtx_lock(&mountlist_mtx); 2758 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 2759 mtx_unlock(&mountlist_mtx); 2760 return (0); 2761 } 2762 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 2763 vfs_unbusy(mp, td); 2764 return (0); 2765 } 2766 asyncflag = mp->mnt_flag & MNT_ASYNC; 2767 mp->mnt_flag &= ~MNT_ASYNC; 2768 vfs_msync(mp, MNT_NOWAIT); 2769 VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 2770 if (asyncflag) 2771 mp->mnt_flag |= MNT_ASYNC; 2772 vn_finished_write(mp); 2773 vfs_unbusy(mp, td); 2774 return (0); 2775 } 2776 2777 /* 2778 * The syncer vnode is no referenced. 2779 */ 2780 static int 2781 sync_inactive(ap) 2782 struct vop_inactive_args /* { 2783 struct vnode *a_vp; 2784 struct thread *a_td; 2785 } */ *ap; 2786 { 2787 2788 vgone(ap->a_vp); 2789 return (0); 2790 } 2791 2792 /* 2793 * The syncer vnode is no longer needed and is being decommissioned. 2794 * 2795 * Modifications to the worklist must be protected at splbio(). 2796 */ 2797 static int 2798 sync_reclaim(ap) 2799 struct vop_reclaim_args /* { 2800 struct vnode *a_vp; 2801 } */ *ap; 2802 { 2803 struct vnode *vp = ap->a_vp; 2804 int s; 2805 2806 s = splbio(); 2807 vp->v_mount->mnt_syncer = NULL; 2808 if (vp->v_flag & VONWORKLST) { 2809 LIST_REMOVE(vp, v_synclist); 2810 vp->v_flag &= ~VONWORKLST; 2811 } 2812 splx(s); 2813 2814 return (0); 2815 } 2816 2817 /* 2818 * Print out a syncer vnode. 2819 */ 2820 static int 2821 sync_print(ap) 2822 struct vop_print_args /* { 2823 struct vnode *a_vp; 2824 } */ *ap; 2825 { 2826 struct vnode *vp = ap->a_vp; 2827 2828 printf("syncer vnode"); 2829 if (vp->v_vnlock != NULL) 2830 lockmgr_printinfo(vp->v_vnlock); 2831 printf("\n"); 2832 return (0); 2833 } 2834 2835 /* 2836 * extract the dev_t from a VCHR 2837 */ 2838 dev_t 2839 vn_todev(vp) 2840 struct vnode *vp; 2841 { 2842 if (vp->v_type != VCHR) 2843 return (NODEV); 2844 return (vp->v_rdev); 2845 } 2846 2847 /* 2848 * Check if vnode represents a disk device 2849 */ 2850 int 2851 vn_isdisk(vp, errp) 2852 struct vnode *vp; 2853 int *errp; 2854 { 2855 struct cdevsw *cdevsw; 2856 2857 if (vp->v_type != VCHR) { 2858 if (errp != NULL) 2859 *errp = ENOTBLK; 2860 return (0); 2861 } 2862 if (vp->v_rdev == NULL) { 2863 if (errp != NULL) 2864 *errp = ENXIO; 2865 return (0); 2866 } 2867 cdevsw = devsw(vp->v_rdev); 2868 if (cdevsw == NULL) { 2869 if (errp != NULL) 2870 *errp = ENXIO; 2871 return (0); 2872 } 2873 if (!(cdevsw->d_flags & D_DISK)) { 2874 if (errp != NULL) 2875 *errp = ENOTBLK; 2876 return (0); 2877 } 2878 if (errp != NULL) 2879 *errp = 0; 2880 return (1); 2881 } 2882 2883 /* 2884 * Free data allocated by namei(); see namei(9) for details. 2885 */ 2886 void 2887 NDFREE(ndp, flags) 2888 struct nameidata *ndp; 2889 const uint flags; 2890 { 2891 if (!(flags & NDF_NO_FREE_PNBUF) && 2892 (ndp->ni_cnd.cn_flags & HASBUF)) { 2893 zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 2894 ndp->ni_cnd.cn_flags &= ~HASBUF; 2895 } 2896 if (!(flags & NDF_NO_DVP_UNLOCK) && 2897 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 2898 ndp->ni_dvp != ndp->ni_vp) 2899 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 2900 if (!(flags & NDF_NO_DVP_RELE) && 2901 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 2902 vrele(ndp->ni_dvp); 2903 ndp->ni_dvp = NULL; 2904 } 2905 if (!(flags & NDF_NO_VP_UNLOCK) && 2906 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 2907 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 2908 if (!(flags & NDF_NO_VP_RELE) && 2909 ndp->ni_vp) { 2910 vrele(ndp->ni_vp); 2911 ndp->ni_vp = NULL; 2912 } 2913 if (!(flags & NDF_NO_STARTDIR_RELE) && 2914 (ndp->ni_cnd.cn_flags & SAVESTART)) { 2915 vrele(ndp->ni_startdir); 2916 ndp->ni_startdir = NULL; 2917 } 2918 } 2919 2920 /* 2921 * Common file system object access control check routine. Accepts a 2922 * vnode's type, "mode", uid and gid, requested access mode, credentials, 2923 * and optional call-by-reference privused argument allowing vaccess() 2924 * to indicate to the caller whether privilege was used to satisfy the 2925 * request. Returns 0 on success, or an errno on failure. 2926 */ 2927 int 2928 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 2929 enum vtype type; 2930 mode_t file_mode; 2931 uid_t file_uid; 2932 gid_t file_gid; 2933 mode_t acc_mode; 2934 struct ucred *cred; 2935 int *privused; 2936 { 2937 mode_t dac_granted; 2938 #ifdef CAPABILITIES 2939 mode_t cap_granted; 2940 #endif 2941 2942 /* 2943 * Look for a normal, non-privileged way to access the file/directory 2944 * as requested. If it exists, go with that. 2945 */ 2946 2947 if (privused != NULL) 2948 *privused = 0; 2949 2950 dac_granted = 0; 2951 2952 /* Check the owner. */ 2953 if (cred->cr_uid == file_uid) { 2954 dac_granted |= VADMIN; 2955 if (file_mode & S_IXUSR) 2956 dac_granted |= VEXEC; 2957 if (file_mode & S_IRUSR) 2958 dac_granted |= VREAD; 2959 if (file_mode & S_IWUSR) 2960 dac_granted |= VWRITE; 2961 2962 if ((acc_mode & dac_granted) == acc_mode) 2963 return (0); 2964 2965 goto privcheck; 2966 } 2967 2968 /* Otherwise, check the groups (first match) */ 2969 if (groupmember(file_gid, cred)) { 2970 if (file_mode & S_IXGRP) 2971 dac_granted |= VEXEC; 2972 if (file_mode & S_IRGRP) 2973 dac_granted |= VREAD; 2974 if (file_mode & S_IWGRP) 2975 dac_granted |= VWRITE; 2976 2977 if ((acc_mode & dac_granted) == acc_mode) 2978 return (0); 2979 2980 goto privcheck; 2981 } 2982 2983 /* Otherwise, check everyone else. */ 2984 if (file_mode & S_IXOTH) 2985 dac_granted |= VEXEC; 2986 if (file_mode & S_IROTH) 2987 dac_granted |= VREAD; 2988 if (file_mode & S_IWOTH) 2989 dac_granted |= VWRITE; 2990 if ((acc_mode & dac_granted) == acc_mode) 2991 return (0); 2992 2993 privcheck: 2994 if (!suser_xxx(cred, NULL, PRISON_ROOT)) { 2995 /* XXX audit: privilege used */ 2996 if (privused != NULL) 2997 *privused = 1; 2998 return (0); 2999 } 3000 3001 #ifdef CAPABILITIES 3002 /* 3003 * Build a capability mask to determine if the set of capabilities 3004 * satisfies the requirements when combined with the granted mask 3005 * from above. 3006 * For each capability, if the capability is required, bitwise 3007 * or the request type onto the cap_granted mask. 3008 */ 3009 cap_granted = 0; 3010 3011 if (type == VDIR) { 3012 /* 3013 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3014 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3015 */ 3016 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3017 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3018 cap_granted |= VEXEC; 3019 } else { 3020 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3021 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3022 cap_granted |= VEXEC; 3023 } 3024 3025 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3026 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3027 cap_granted |= VREAD; 3028 3029 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3030 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3031 cap_granted |= VWRITE; 3032 3033 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3034 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3035 cap_granted |= VADMIN; 3036 3037 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3038 /* XXX audit: privilege used */ 3039 if (privused != NULL) 3040 *privused = 1; 3041 return (0); 3042 } 3043 #endif 3044 3045 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3046 } 3047 3048