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_mac.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/mac.h> 58 #include <sys/malloc.h> 59 #include <sys/mount.h> 60 #include <sys/namei.h> 61 #include <sys/stat.h> 62 #include <sys/sysctl.h> 63 #include <sys/syslog.h> 64 #include <sys/vmmeter.h> 65 #include <sys/vnode.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_object.h> 69 #include <vm/vm_extern.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_page.h> 73 #include <vm/uma.h> 74 75 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 76 77 static void addalias(struct vnode *vp, dev_t nvp_rdev); 78 static void insmntque(struct vnode *vp, struct mount *mp); 79 static void vclean(struct vnode *vp, int flags, struct thread *td); 80 static void vlruvp(struct vnode *vp); 81 static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, 82 int slpflag, int slptimeo, int *errorp); 83 static int vcanrecycle(struct vnode *vp); 84 85 86 /* 87 * Number of vnodes in existence. Increased whenever getnewvnode() 88 * allocates a new vnode, never decreased. 89 */ 90 static unsigned long numvnodes; 91 92 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 93 94 /* 95 * Conversion tables for conversion from vnode types to inode formats 96 * and back. 97 */ 98 enum vtype iftovt_tab[16] = { 99 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 100 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 101 }; 102 int vttoif_tab[9] = { 103 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 104 S_IFSOCK, S_IFIFO, S_IFMT, 105 }; 106 107 /* 108 * List of vnodes that are ready for recycling. 109 */ 110 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 111 112 /* 113 * Minimum number of free vnodes. If there are fewer than this free vnodes, 114 * getnewvnode() will return a newly allocated vnode. 115 */ 116 static u_long wantfreevnodes = 25; 117 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 118 /* Number of vnodes in the free list. */ 119 static u_long freevnodes; 120 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 121 122 /* 123 * Various variables used for debugging the new implementation of 124 * reassignbuf(). 125 * XXX these are probably of (very) limited utility now. 126 */ 127 static int reassignbufcalls; 128 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 129 static int nameileafonly; 130 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 131 132 #ifdef ENABLE_VFS_IOOPT 133 /* See NOTES for a description of this setting. */ 134 int vfs_ioopt; 135 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, ""); 136 #endif 137 138 /* 139 * Cache for the mount type id assigned to NFS. This is used for 140 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 141 */ 142 int nfs_mount_type = -1; 143 144 /* To keep more than one thread at a time from running vfs_getnewfsid */ 145 static struct mtx mntid_mtx; 146 147 /* 148 * Lock for any access to the following: 149 * vnode_free_list 150 * numvnodes 151 * freevnodes 152 */ 153 static struct mtx vnode_free_list_mtx; 154 155 /* 156 * For any iteration/modification of dev->si_hlist (linked through 157 * v_specnext) 158 */ 159 static struct mtx spechash_mtx; 160 161 /* Publicly exported FS */ 162 struct nfs_public nfs_pub; 163 164 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 165 static uma_zone_t vnode_zone; 166 static uma_zone_t vnodepoll_zone; 167 168 /* Set to 1 to print out reclaim of active vnodes */ 169 int prtactive; 170 171 /* 172 * The workitem queue. 173 * 174 * It is useful to delay writes of file data and filesystem metadata 175 * for tens of seconds so that quickly created and deleted files need 176 * not waste disk bandwidth being created and removed. To realize this, 177 * we append vnodes to a "workitem" queue. When running with a soft 178 * updates implementation, most pending metadata dependencies should 179 * not wait for more than a few seconds. Thus, mounted on block devices 180 * are delayed only about a half the time that file data is delayed. 181 * Similarly, directory updates are more critical, so are only delayed 182 * about a third the time that file data is delayed. Thus, there are 183 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 184 * one each second (driven off the filesystem syncer process). The 185 * syncer_delayno variable indicates the next queue that is to be processed. 186 * Items that need to be processed soon are placed in this queue: 187 * 188 * syncer_workitem_pending[syncer_delayno] 189 * 190 * A delay of fifteen seconds is done by placing the request fifteen 191 * entries later in the queue: 192 * 193 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 194 * 195 */ 196 static int syncer_delayno; 197 static long syncer_mask; 198 LIST_HEAD(synclist, vnode); 199 static struct synclist *syncer_workitem_pending; 200 201 #define SYNCER_MAXDELAY 32 202 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 203 static int syncdelay = 30; /* max time to delay syncing data */ 204 static int filedelay = 30; /* time to delay syncing files */ 205 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 206 static int dirdelay = 29; /* time to delay syncing directories */ 207 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 208 static int metadelay = 28; /* time to delay syncing metadata */ 209 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 210 static int rushjob; /* number of slots to run ASAP */ 211 static int stat_rush_requests; /* number of times I/O speeded up */ 212 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 213 214 /* 215 * Number of vnodes we want to exist at any one time. This is mostly used 216 * to size hash tables in vnode-related code. It is normally not used in 217 * getnewvnode(), as wantfreevnodes is normally nonzero.) 218 * 219 * XXX desiredvnodes is historical cruft and should not exist. 220 */ 221 int desiredvnodes; 222 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 223 &desiredvnodes, 0, "Maximum number of vnodes"); 224 static int minvnodes; 225 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 226 &minvnodes, 0, "Minimum number of vnodes"); 227 static int vnlru_nowhere; 228 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, 229 "Number of times the vnlru process ran without success"); 230 231 /* Hook for calling soft updates */ 232 int (*softdep_process_worklist_hook)(struct mount *); 233 234 #ifdef DEBUG_VFS_LOCKS 235 /* Print lock violations */ 236 int vfs_badlock_print = 1; 237 238 /* Panic on violation */ 239 int vfs_badlock_panic = 1; 240 241 /* Check for interlock across VOPs */ 242 int vfs_badlock_mutex = 0; 243 244 void 245 vop_rename_pre(void *ap) 246 { 247 struct vop_rename_args *a = ap; 248 249 if (a->a_tvp) 250 ASSERT_VI_UNLOCKED(a->a_tvp); 251 ASSERT_VI_UNLOCKED(a->a_tdvp); 252 ASSERT_VI_UNLOCKED(a->a_fvp); 253 ASSERT_VI_UNLOCKED(a->a_fdvp); 254 255 /* Check the source (from) */ 256 if (a->a_tdvp != a->a_fdvp) 257 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); 258 if (a->a_tvp != a->a_fvp) 259 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); 260 261 /* Check the target */ 262 if (a->a_tvp) 263 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); 264 265 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); 266 } 267 268 void 269 vop_strategy_pre(void *ap) 270 { 271 struct vop_strategy_args *a = ap; 272 struct buf *bp; 273 274 bp = a->a_bp; 275 276 /* 277 * Cluster ops lock their component buffers but not the IO container. 278 */ 279 if ((bp->b_flags & B_CLUSTER) != 0) 280 return; 281 282 if (BUF_REFCNT(bp) < 1) { 283 if (vfs_badlock_print) 284 printf("VOP_STRATEGY: bp is not locked but should be.\n"); 285 if (vfs_badlock_panic) 286 Debugger("Lock violation.\n"); 287 } 288 } 289 290 void 291 vop_lookup_pre(void *ap) 292 { 293 struct vop_lookup_args *a = ap; 294 struct vnode *dvp; 295 296 dvp = a->a_dvp; 297 298 ASSERT_VI_UNLOCKED(dvp); 299 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 300 } 301 302 void 303 vop_lookup_post(void *ap, int rc) 304 { 305 struct vop_lookup_args *a = ap; 306 struct componentname *cnp; 307 struct vnode *dvp; 308 struct vnode *vp; 309 int flags; 310 311 dvp = a->a_dvp; 312 cnp = a->a_cnp; 313 vp = *(a->a_vpp); 314 flags = cnp->cn_flags; 315 316 317 ASSERT_VI_UNLOCKED(dvp); 318 /* 319 * If this is the last path component for this lookup and LOCPARENT 320 * is set, OR if there is an error the directory has to be locked. 321 */ 322 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 323 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 324 else if (rc != 0) 325 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 326 else if (dvp != vp) 327 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 328 329 if (flags & PDIRUNLOCK) 330 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 331 332 if (rc == 0) { 333 ASSERT_VI_UNLOCKED(vp); 334 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (vpp)"); 335 } 336 } 337 338 void 339 vop_unlock_pre(void *ap) 340 { 341 struct vop_unlock_args *a = ap; 342 343 if ((a->a_flags & LK_INTERLOCK) == 0) 344 ASSERT_VI_UNLOCKED(a->a_vp); 345 else 346 ASSERT_VI_LOCKED(a->a_vp); 347 } 348 349 void 350 vop_unlock_post(void *ap, int rc) 351 { 352 struct vop_unlock_args *a = ap; 353 354 ASSERT_VI_UNLOCKED(a->a_vp); 355 } 356 357 void 358 vop_lock_pre(void *ap) 359 { 360 struct vop_lock_args *a = ap; 361 362 if ((a->a_flags & LK_INTERLOCK) == 0) 363 ASSERT_VI_UNLOCKED(a->a_vp); 364 else 365 ASSERT_VI_LOCKED(a->a_vp); 366 } 367 368 void 369 vop_lock_post(void *ap, int rc) 370 { 371 struct vop_lock_args *a = ap; 372 373 ASSERT_VI_UNLOCKED(a->a_vp); 374 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 375 } 376 377 #endif /* DEBUG_VFS_LOCKS */ 378 379 void 380 v_addpollinfo(struct vnode *vp) 381 { 382 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 383 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 384 } 385 386 /* 387 * Initialize the vnode management data structures. 388 */ 389 static void 390 vntblinit(void *dummy __unused) 391 { 392 393 desiredvnodes = maxproc + cnt.v_page_count / 4; 394 minvnodes = desiredvnodes / 4; 395 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 396 mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); 397 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 398 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 399 TAILQ_INIT(&vnode_free_list); 400 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 401 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 402 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 403 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 404 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 405 /* 406 * Initialize the filesystem syncer. 407 */ 408 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 409 &syncer_mask); 410 syncer_maxdelay = syncer_mask + 1; 411 } 412 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 413 414 415 /* 416 * Mark a mount point as busy. Used to synchronize access and to delay 417 * unmounting. Interlock is not released on failure. 418 */ 419 int 420 vfs_busy(mp, flags, interlkp, td) 421 struct mount *mp; 422 int flags; 423 struct mtx *interlkp; 424 struct thread *td; 425 { 426 int lkflags; 427 428 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 429 if (flags & LK_NOWAIT) 430 return (ENOENT); 431 mp->mnt_kern_flag |= MNTK_MWAIT; 432 /* 433 * Since all busy locks are shared except the exclusive 434 * lock granted when unmounting, the only place that a 435 * wakeup needs to be done is at the release of the 436 * exclusive lock at the end of dounmount. 437 */ 438 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 439 return (ENOENT); 440 } 441 lkflags = LK_SHARED | LK_NOPAUSE; 442 if (interlkp) 443 lkflags |= LK_INTERLOCK; 444 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 445 panic("vfs_busy: unexpected lock failure"); 446 return (0); 447 } 448 449 /* 450 * Free a busy filesystem. 451 */ 452 void 453 vfs_unbusy(mp, td) 454 struct mount *mp; 455 struct thread *td; 456 { 457 458 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 459 } 460 461 /* 462 * Lookup a mount point by filesystem identifier. 463 */ 464 struct mount * 465 vfs_getvfs(fsid) 466 fsid_t *fsid; 467 { 468 register struct mount *mp; 469 470 mtx_lock(&mountlist_mtx); 471 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 472 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 473 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 474 mtx_unlock(&mountlist_mtx); 475 return (mp); 476 } 477 } 478 mtx_unlock(&mountlist_mtx); 479 return ((struct mount *) 0); 480 } 481 482 /* 483 * Get a new unique fsid. Try to make its val[0] unique, since this value 484 * will be used to create fake device numbers for stat(). Also try (but 485 * not so hard) make its val[0] unique mod 2^16, since some emulators only 486 * support 16-bit device numbers. We end up with unique val[0]'s for the 487 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 488 * 489 * Keep in mind that several mounts may be running in parallel. Starting 490 * the search one past where the previous search terminated is both a 491 * micro-optimization and a defense against returning the same fsid to 492 * different mounts. 493 */ 494 void 495 vfs_getnewfsid(mp) 496 struct mount *mp; 497 { 498 static u_int16_t mntid_base; 499 fsid_t tfsid; 500 int mtype; 501 502 mtx_lock(&mntid_mtx); 503 mtype = mp->mnt_vfc->vfc_typenum; 504 tfsid.val[1] = mtype; 505 mtype = (mtype & 0xFF) << 24; 506 for (;;) { 507 tfsid.val[0] = makeudev(255, 508 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 509 mntid_base++; 510 if (vfs_getvfs(&tfsid) == NULL) 511 break; 512 } 513 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 514 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 515 mtx_unlock(&mntid_mtx); 516 } 517 518 /* 519 * Knob to control the precision of file timestamps: 520 * 521 * 0 = seconds only; nanoseconds zeroed. 522 * 1 = seconds and nanoseconds, accurate within 1/HZ. 523 * 2 = seconds and nanoseconds, truncated to microseconds. 524 * >=3 = seconds and nanoseconds, maximum precision. 525 */ 526 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 527 528 static int timestamp_precision = TSP_SEC; 529 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 530 ×tamp_precision, 0, ""); 531 532 /* 533 * Get a current timestamp. 534 */ 535 void 536 vfs_timestamp(tsp) 537 struct timespec *tsp; 538 { 539 struct timeval tv; 540 541 switch (timestamp_precision) { 542 case TSP_SEC: 543 tsp->tv_sec = time_second; 544 tsp->tv_nsec = 0; 545 break; 546 case TSP_HZ: 547 getnanotime(tsp); 548 break; 549 case TSP_USEC: 550 microtime(&tv); 551 TIMEVAL_TO_TIMESPEC(&tv, tsp); 552 break; 553 case TSP_NSEC: 554 default: 555 nanotime(tsp); 556 break; 557 } 558 } 559 560 /* 561 * Set vnode attributes to VNOVAL 562 */ 563 void 564 vattr_null(vap) 565 register struct vattr *vap; 566 { 567 568 vap->va_type = VNON; 569 vap->va_size = VNOVAL; 570 vap->va_bytes = VNOVAL; 571 vap->va_mode = VNOVAL; 572 vap->va_nlink = VNOVAL; 573 vap->va_uid = VNOVAL; 574 vap->va_gid = VNOVAL; 575 vap->va_fsid = VNOVAL; 576 vap->va_fileid = VNOVAL; 577 vap->va_blocksize = VNOVAL; 578 vap->va_rdev = VNOVAL; 579 vap->va_atime.tv_sec = VNOVAL; 580 vap->va_atime.tv_nsec = VNOVAL; 581 vap->va_mtime.tv_sec = VNOVAL; 582 vap->va_mtime.tv_nsec = VNOVAL; 583 vap->va_ctime.tv_sec = VNOVAL; 584 vap->va_ctime.tv_nsec = VNOVAL; 585 vap->va_birthtime.tv_sec = VNOVAL; 586 vap->va_birthtime.tv_nsec = VNOVAL; 587 vap->va_flags = VNOVAL; 588 vap->va_gen = VNOVAL; 589 vap->va_vaflags = 0; 590 } 591 592 /* 593 * This routine is called when we have too many vnodes. It attempts 594 * to free <count> vnodes and will potentially free vnodes that still 595 * have VM backing store (VM backing store is typically the cause 596 * of a vnode blowout so we want to do this). Therefore, this operation 597 * is not considered cheap. 598 * 599 * A number of conditions may prevent a vnode from being reclaimed. 600 * the buffer cache may have references on the vnode, a directory 601 * vnode may still have references due to the namei cache representing 602 * underlying files, or the vnode may be in active use. It is not 603 * desireable to reuse such vnodes. These conditions may cause the 604 * number of vnodes to reach some minimum value regardless of what 605 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 606 */ 607 static int 608 vlrureclaim(struct mount *mp, int count) 609 { 610 struct vnode *vp; 611 int done; 612 int trigger; 613 int usevnodes; 614 615 /* 616 * Calculate the trigger point, don't allow user 617 * screwups to blow us up. This prevents us from 618 * recycling vnodes with lots of resident pages. We 619 * aren't trying to free memory, we are trying to 620 * free vnodes. 621 */ 622 usevnodes = desiredvnodes; 623 if (usevnodes <= 0) 624 usevnodes = 1; 625 trigger = cnt.v_page_count * 2 / usevnodes; 626 627 done = 0; 628 mtx_lock(&mntvnode_mtx); 629 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 630 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 631 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 632 633 if (vp->v_type != VNON && 634 vp->v_type != VBAD && 635 VI_TRYLOCK(vp)) { 636 if (VMIGHTFREE(vp) && /* critical path opt */ 637 (vp->v_object == NULL || 638 vp->v_object->resident_page_count < trigger)) { 639 mtx_unlock(&mntvnode_mtx); 640 vgonel(vp, curthread); 641 done++; 642 mtx_lock(&mntvnode_mtx); 643 } else 644 VI_UNLOCK(vp); 645 } 646 --count; 647 } 648 mtx_unlock(&mntvnode_mtx); 649 return done; 650 } 651 652 /* 653 * Attempt to recycle vnodes in a context that is always safe to block. 654 * Calling vlrurecycle() from the bowels of filesystem code has some 655 * interesting deadlock problems. 656 */ 657 static struct proc *vnlruproc; 658 static int vnlruproc_sig; 659 660 static void 661 vnlru_proc(void) 662 { 663 struct mount *mp, *nmp; 664 int s; 665 int done; 666 struct proc *p = vnlruproc; 667 struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 668 669 mtx_lock(&Giant); 670 671 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 672 SHUTDOWN_PRI_FIRST); 673 674 s = splbio(); 675 for (;;) { 676 kthread_suspend_check(p); 677 mtx_lock(&vnode_free_list_mtx); 678 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 679 mtx_unlock(&vnode_free_list_mtx); 680 vnlruproc_sig = 0; 681 tsleep(vnlruproc, PVFS, "vlruwt", 0); 682 continue; 683 } 684 mtx_unlock(&vnode_free_list_mtx); 685 done = 0; 686 mtx_lock(&mountlist_mtx); 687 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 688 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 689 nmp = TAILQ_NEXT(mp, mnt_list); 690 continue; 691 } 692 done += vlrureclaim(mp, 10); 693 mtx_lock(&mountlist_mtx); 694 nmp = TAILQ_NEXT(mp, mnt_list); 695 vfs_unbusy(mp, td); 696 } 697 mtx_unlock(&mountlist_mtx); 698 if (done == 0) { 699 #if 0 700 /* These messages are temporary debugging aids */ 701 if (vnlru_nowhere < 5) 702 printf("vnlru process getting nowhere..\n"); 703 else if (vnlru_nowhere == 5) 704 printf("vnlru process messages stopped.\n"); 705 #endif 706 vnlru_nowhere++; 707 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 708 } 709 } 710 splx(s); 711 } 712 713 static struct kproc_desc vnlru_kp = { 714 "vnlru", 715 vnlru_proc, 716 &vnlruproc 717 }; 718 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 719 720 721 /* 722 * Routines having to do with the management of the vnode table. 723 */ 724 725 /* 726 * Check to see if a free vnode can be recycled. If it can, return it locked 727 * with the vn lock, but not interlock. Otherwise indicate the error. 728 */ 729 static int 730 vcanrecycle(struct vnode *vp) 731 { 732 struct thread *td = curthread; 733 vm_object_t object; 734 int error; 735 736 /* Don't recycle if we can't get the interlock */ 737 if (!mtx_trylock(&vp->v_interlock)) 738 return (EWOULDBLOCK); 739 740 /* We should be able to immediately acquire this */ 741 /* XXX This looks like it should panic if it fails */ 742 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) { 743 VI_UNLOCK(vp); 744 return (EWOULDBLOCK); 745 } 746 /* 747 * Don't recycle if we still have cached pages. 748 */ 749 if (VOP_GETVOBJECT(vp, &object) == 0 && 750 (object->resident_page_count || 751 object->ref_count)) { 752 error = EBUSY; 753 goto done; 754 } 755 if (LIST_FIRST(&vp->v_cache_src)) { 756 /* 757 * note: nameileafonly sysctl is temporary, 758 * for debugging only, and will eventually be 759 * removed. 760 */ 761 if (nameileafonly > 0) { 762 /* 763 * Do not reuse namei-cached directory 764 * vnodes that have cached 765 * subdirectories. 766 */ 767 if (cache_leaf_test(vp) < 0) { 768 error = EISDIR; 769 goto done; 770 } 771 } else if (nameileafonly < 0 || 772 vmiodirenable == 0) { 773 /* 774 * Do not reuse namei-cached directory 775 * vnodes if nameileafonly is -1 or 776 * if VMIO backing for directories is 777 * turned off (otherwise we reuse them 778 * too quickly). 779 */ 780 error = EBUSY; 781 goto done; 782 } 783 } 784 return (0); 785 done: 786 VOP_UNLOCK(vp, 0, td); 787 return (error); 788 } 789 790 /* 791 * Return the next vnode from the free list. 792 */ 793 int 794 getnewvnode(tag, mp, vops, vpp) 795 enum vtagtype tag; 796 struct mount *mp; 797 vop_t **vops; 798 struct vnode **vpp; 799 { 800 int s; 801 struct thread *td = curthread; /* XXX */ 802 struct vnode *vp = NULL; 803 struct mount *vnmp; 804 805 s = splbio(); 806 mtx_lock(&vnode_free_list_mtx); 807 808 /* 809 * Try to reuse vnodes if we hit the max. This situation only 810 * occurs in certain large-memory (2G+) situations. We cannot 811 * attempt to directly reclaim vnodes due to nasty recursion 812 * problems. 813 */ 814 if (vnlruproc_sig == 0 && numvnodes - freevnodes > desiredvnodes) { 815 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 816 wakeup(vnlruproc); 817 } 818 819 /* 820 * Attempt to reuse a vnode already on the free list, allocating 821 * a new vnode if we can't find one or if we have not reached a 822 * good minimum for good LRU performance. 823 */ 824 825 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 826 int error; 827 int count; 828 829 for (count = 0; count < freevnodes; count++) { 830 vp = TAILQ_FIRST(&vnode_free_list); 831 832 KASSERT(vp->v_usecount == 0, 833 ("getnewvnode: free vnode isn't")); 834 835 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 836 /* 837 * We have to drop the free list mtx to avoid lock 838 * order reversals with interlock. 839 */ 840 mtx_unlock(&vnode_free_list_mtx); 841 error = vcanrecycle(vp); 842 /* 843 * Skip over it if its filesystem is being suspended. 844 */ 845 if (error == 0 && 846 vn_start_write(vp, &vnmp, V_NOWAIT) != 0) 847 error = EBUSY; 848 849 mtx_lock(&vnode_free_list_mtx); 850 if (error != 0) 851 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 852 v_freelist); 853 else 854 break; 855 } 856 } 857 /* 858 * Unlocked access to this vp is ok because we are assured that there 859 * are no other references to it. 860 */ 861 if (vp) { 862 freevnodes--; 863 mtx_unlock(&vnode_free_list_mtx); 864 865 vp->v_iflag |= VI_DOOMED; 866 vp->v_iflag &= ~VI_FREE; 867 cache_purge(vp); 868 if (vp->v_type != VBAD) { 869 VOP_UNLOCK(vp, 0, td); 870 vgone(vp); 871 } else { 872 VOP_UNLOCK(vp, 0, td); 873 } 874 vn_finished_write(vnmp); 875 876 #ifdef INVARIANTS 877 { 878 if (vp->v_data) 879 panic("cleaned vnode isn't"); 880 VI_LOCK(vp); 881 if (vp->v_numoutput) 882 panic("Clean vnode has pending I/O's"); 883 if (vp->v_writecount != 0) 884 panic("Non-zero write count"); 885 VI_UNLOCK(vp); 886 } 887 #endif 888 if (vp->v_pollinfo) { 889 mtx_destroy(&vp->v_pollinfo->vpi_lock); 890 uma_zfree(vnodepoll_zone, vp->v_pollinfo); 891 } 892 vp->v_pollinfo = NULL; 893 #ifdef MAC 894 mac_destroy_vnode(vp); 895 #endif 896 vp->v_iflag = 0; 897 vp->v_vflag = 0; 898 vp->v_lastw = 0; 899 vp->v_lasta = 0; 900 vp->v_cstart = 0; 901 vp->v_clen = 0; 902 vp->v_socket = 0; 903 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 904 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 905 } else { 906 numvnodes++; 907 mtx_unlock(&vnode_free_list_mtx); 908 909 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 910 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 911 vp->v_dd = vp; 912 cache_purge(vp); 913 LIST_INIT(&vp->v_cache_src); 914 TAILQ_INIT(&vp->v_cache_dst); 915 } 916 917 TAILQ_INIT(&vp->v_cleanblkhd); 918 TAILQ_INIT(&vp->v_dirtyblkhd); 919 vp->v_type = VNON; 920 vp->v_tag = tag; 921 vp->v_op = vops; 922 lockinit(&vp->v_lock, PVFS, "vnlock", VLKTIMEOUT, LK_NOPAUSE); 923 #ifdef MAC 924 mac_init_vnode(vp); 925 #endif 926 insmntque(vp, mp); 927 *vpp = vp; 928 vp->v_usecount = 1; 929 vp->v_data = 0; 930 vp->v_cachedid = -1; 931 932 splx(s); 933 934 #if 0 935 mp_fixme("This code does not lock access to numvnodes && freevnodes."); 936 vnodeallocs++; 937 if (vnodeallocs % vnoderecycleperiod == 0 && 938 freevnodes < vnoderecycleminfreevn && 939 vnoderecyclemintotalvn < numvnodes) { 940 /* Recycle vnodes. */ 941 cache_purgeleafdirs(vnoderecyclenumber); 942 } 943 #endif 944 945 return (0); 946 } 947 948 /* 949 * Move a vnode from one mount queue to another. 950 */ 951 static void 952 insmntque(vp, mp) 953 register struct vnode *vp; 954 register struct mount *mp; 955 { 956 957 mtx_lock(&mntvnode_mtx); 958 /* 959 * Delete from old mount point vnode list, if on one. 960 */ 961 if (vp->v_mount != NULL) 962 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 963 /* 964 * Insert into list of vnodes for the new mount point, if available. 965 */ 966 if ((vp->v_mount = mp) == NULL) { 967 mtx_unlock(&mntvnode_mtx); 968 return; 969 } 970 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 971 mtx_unlock(&mntvnode_mtx); 972 } 973 974 /* 975 * Update outstanding I/O count and do wakeup if requested. 976 */ 977 void 978 vwakeup(bp) 979 register struct buf *bp; 980 { 981 register struct vnode *vp; 982 983 bp->b_flags &= ~B_WRITEINPROG; 984 if ((vp = bp->b_vp)) { 985 VI_LOCK(vp); 986 vp->v_numoutput--; 987 if (vp->v_numoutput < 0) 988 panic("vwakeup: neg numoutput"); 989 if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { 990 vp->v_iflag &= ~VI_BWAIT; 991 wakeup(&vp->v_numoutput); 992 } 993 VI_UNLOCK(vp); 994 } 995 } 996 997 /* 998 * Flush out and invalidate all buffers associated with a vnode. 999 * Called with the underlying object locked. 1000 */ 1001 int 1002 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 1003 struct vnode *vp; 1004 int flags; 1005 struct ucred *cred; 1006 struct thread *td; 1007 int slpflag, slptimeo; 1008 { 1009 struct buf *blist; 1010 int s, error; 1011 vm_object_t object; 1012 1013 GIANT_REQUIRED; 1014 1015 if (flags & V_SAVE) { 1016 s = splbio(); 1017 VI_LOCK(vp); 1018 while (vp->v_numoutput) { 1019 vp->v_iflag |= VI_BWAIT; 1020 error = msleep(&vp->v_numoutput, VI_MTX(vp), 1021 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 1022 if (error) { 1023 VI_UNLOCK(vp); 1024 splx(s); 1025 return (error); 1026 } 1027 } 1028 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1029 splx(s); 1030 VI_UNLOCK(vp); 1031 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 1032 return (error); 1033 /* 1034 * XXX We could save a lock/unlock if this was only 1035 * enabled under INVARIANTS 1036 */ 1037 VI_LOCK(vp); 1038 s = splbio(); 1039 if (vp->v_numoutput > 0 || 1040 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 1041 panic("vinvalbuf: dirty bufs"); 1042 } 1043 VI_UNLOCK(vp); 1044 splx(s); 1045 } 1046 s = splbio(); 1047 for (error = 0;;) { 1048 if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && 1049 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1050 if (error) 1051 break; 1052 continue; 1053 } 1054 if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && 1055 flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { 1056 if (error) 1057 break; 1058 continue; 1059 } 1060 break; 1061 } 1062 if (error) { 1063 splx(s); 1064 return (error); 1065 } 1066 1067 /* 1068 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1069 * have write I/O in-progress but if there is a VM object then the 1070 * VM object can also have read-I/O in-progress. 1071 */ 1072 VI_LOCK(vp); 1073 do { 1074 while (vp->v_numoutput > 0) { 1075 vp->v_iflag |= VI_BWAIT; 1076 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); 1077 } 1078 VI_UNLOCK(vp); 1079 if (VOP_GETVOBJECT(vp, &object) == 0) { 1080 while (object->paging_in_progress) 1081 vm_object_pip_sleep(object, "vnvlbx"); 1082 } 1083 VI_LOCK(vp); 1084 } while (vp->v_numoutput > 0); 1085 VI_UNLOCK(vp); 1086 1087 splx(s); 1088 1089 /* 1090 * Destroy the copy in the VM cache, too. 1091 */ 1092 if (VOP_GETVOBJECT(vp, &object) == 0) { 1093 vm_object_page_remove(object, 0, 0, 1094 (flags & V_SAVE) ? TRUE : FALSE); 1095 } 1096 1097 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1098 (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || 1099 !TAILQ_EMPTY(&vp->v_cleanblkhd))) 1100 panic("vinvalbuf: flush failed"); 1101 return (0); 1102 } 1103 1104 /* 1105 * Flush out buffers on the specified list. 1106 */ 1107 static int 1108 flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) 1109 struct buf *blist; 1110 int flags; 1111 struct vnode *vp; 1112 int slpflag, slptimeo; 1113 int *errorp; 1114 { 1115 struct buf *bp, *nbp; 1116 int found, error; 1117 1118 for (found = 0, bp = blist; bp; bp = nbp) { 1119 nbp = TAILQ_NEXT(bp, b_vnbufs); 1120 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1121 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) 1122 continue; 1123 found += 1; 1124 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1125 error = BUF_TIMELOCK(bp, 1126 LK_EXCLUSIVE | LK_SLEEPFAIL, 1127 "flushbuf", slpflag, slptimeo); 1128 if (error != ENOLCK) 1129 *errorp = error; 1130 return (found); 1131 } 1132 /* 1133 * XXX Since there are no node locks for NFS, I 1134 * believe there is a slight chance that a delayed 1135 * write will occur while sleeping just above, so 1136 * check for it. Note that vfs_bio_awrite expects 1137 * buffers to reside on a queue, while BUF_WRITE and 1138 * brelse do not. 1139 */ 1140 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1141 (flags & V_SAVE)) { 1142 1143 if (bp->b_vp == vp) { 1144 if (bp->b_flags & B_CLUSTEROK) { 1145 BUF_UNLOCK(bp); 1146 vfs_bio_awrite(bp); 1147 } else { 1148 bremfree(bp); 1149 bp->b_flags |= B_ASYNC; 1150 BUF_WRITE(bp); 1151 } 1152 } else { 1153 bremfree(bp); 1154 (void) BUF_WRITE(bp); 1155 } 1156 return (found); 1157 } 1158 bremfree(bp); 1159 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 1160 bp->b_flags &= ~B_ASYNC; 1161 brelse(bp); 1162 } 1163 return (found); 1164 } 1165 1166 /* 1167 * Truncate a file's buffer and pages to a specified length. This 1168 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1169 * sync activity. 1170 */ 1171 int 1172 vtruncbuf(vp, cred, td, length, blksize) 1173 register struct vnode *vp; 1174 struct ucred *cred; 1175 struct thread *td; 1176 off_t length; 1177 int blksize; 1178 { 1179 register struct buf *bp; 1180 struct buf *nbp; 1181 int s, anyfreed; 1182 int trunclbn; 1183 1184 /* 1185 * Round up to the *next* lbn. 1186 */ 1187 trunclbn = (length + blksize - 1) / blksize; 1188 1189 s = splbio(); 1190 restart: 1191 anyfreed = 1; 1192 for (;anyfreed;) { 1193 anyfreed = 0; 1194 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1195 nbp = TAILQ_NEXT(bp, b_vnbufs); 1196 if (bp->b_lblkno >= trunclbn) { 1197 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1198 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1199 goto restart; 1200 } else { 1201 bremfree(bp); 1202 bp->b_flags |= (B_INVAL | B_RELBUF); 1203 bp->b_flags &= ~B_ASYNC; 1204 brelse(bp); 1205 anyfreed = 1; 1206 } 1207 if (nbp && 1208 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1209 (nbp->b_vp != vp) || 1210 (nbp->b_flags & B_DELWRI))) { 1211 goto restart; 1212 } 1213 } 1214 } 1215 1216 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1217 nbp = TAILQ_NEXT(bp, b_vnbufs); 1218 if (bp->b_lblkno >= trunclbn) { 1219 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1220 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1221 goto restart; 1222 } else { 1223 bremfree(bp); 1224 bp->b_flags |= (B_INVAL | B_RELBUF); 1225 bp->b_flags &= ~B_ASYNC; 1226 brelse(bp); 1227 anyfreed = 1; 1228 } 1229 if (nbp && 1230 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1231 (nbp->b_vp != vp) || 1232 (nbp->b_flags & B_DELWRI) == 0)) { 1233 goto restart; 1234 } 1235 } 1236 } 1237 } 1238 1239 if (length > 0) { 1240 restartsync: 1241 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1242 nbp = TAILQ_NEXT(bp, b_vnbufs); 1243 if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { 1244 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1245 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1246 goto restart; 1247 } else { 1248 bremfree(bp); 1249 if (bp->b_vp == vp) { 1250 bp->b_flags |= B_ASYNC; 1251 } else { 1252 bp->b_flags &= ~B_ASYNC; 1253 } 1254 BUF_WRITE(bp); 1255 } 1256 goto restartsync; 1257 } 1258 1259 } 1260 } 1261 1262 VI_LOCK(vp); 1263 while (vp->v_numoutput > 0) { 1264 vp->v_iflag |= VI_BWAIT; 1265 msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); 1266 } 1267 VI_UNLOCK(vp); 1268 splx(s); 1269 1270 vnode_pager_setsize(vp, length); 1271 1272 return (0); 1273 } 1274 1275 /* 1276 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1277 * a vnode. 1278 * 1279 * NOTE: We have to deal with the special case of a background bitmap 1280 * buffer, a situation where two buffers will have the same logical 1281 * block offset. We want (1) only the foreground buffer to be accessed 1282 * in a lookup and (2) must differentiate between the foreground and 1283 * background buffer in the splay tree algorithm because the splay 1284 * tree cannot normally handle multiple entities with the same 'index'. 1285 * We accomplish this by adding differentiating flags to the splay tree's 1286 * numerical domain. 1287 */ 1288 static 1289 struct buf * 1290 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1291 { 1292 struct buf dummy; 1293 struct buf *lefttreemax, *righttreemin, *y; 1294 1295 if (root == NULL) 1296 return (NULL); 1297 lefttreemax = righttreemin = &dummy; 1298 for (;;) { 1299 if (lblkno < root->b_lblkno || 1300 (lblkno == root->b_lblkno && 1301 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1302 if ((y = root->b_left) == NULL) 1303 break; 1304 if (lblkno < y->b_lblkno) { 1305 /* Rotate right. */ 1306 root->b_left = y->b_right; 1307 y->b_right = root; 1308 root = y; 1309 if ((y = root->b_left) == NULL) 1310 break; 1311 } 1312 /* Link into the new root's right tree. */ 1313 righttreemin->b_left = root; 1314 righttreemin = root; 1315 } else if (lblkno > root->b_lblkno || 1316 (lblkno == root->b_lblkno && 1317 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1318 if ((y = root->b_right) == NULL) 1319 break; 1320 if (lblkno > y->b_lblkno) { 1321 /* Rotate left. */ 1322 root->b_right = y->b_left; 1323 y->b_left = root; 1324 root = y; 1325 if ((y = root->b_right) == NULL) 1326 break; 1327 } 1328 /* Link into the new root's left tree. */ 1329 lefttreemax->b_right = root; 1330 lefttreemax = root; 1331 } else { 1332 break; 1333 } 1334 root = y; 1335 } 1336 /* Assemble the new root. */ 1337 lefttreemax->b_right = root->b_left; 1338 righttreemin->b_left = root->b_right; 1339 root->b_left = dummy.b_right; 1340 root->b_right = dummy.b_left; 1341 return (root); 1342 } 1343 1344 static 1345 void 1346 buf_vlist_remove(struct buf *bp) 1347 { 1348 struct vnode *vp = bp->b_vp; 1349 struct buf *root; 1350 1351 if (bp->b_xflags & BX_VNDIRTY) { 1352 if (bp != vp->v_dirtyblkroot) { 1353 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1354 KASSERT(root == bp, ("splay lookup failed during dirty remove")); 1355 } 1356 if (bp->b_left == NULL) { 1357 root = bp->b_right; 1358 } else { 1359 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1360 root->b_right = bp->b_right; 1361 } 1362 vp->v_dirtyblkroot = root; 1363 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1364 } else { 1365 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1366 if (bp != vp->v_cleanblkroot) { 1367 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1368 KASSERT(root == bp, ("splay lookup failed during clean remove")); 1369 } 1370 if (bp->b_left == NULL) { 1371 root = bp->b_right; 1372 } else { 1373 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1374 root->b_right = bp->b_right; 1375 } 1376 vp->v_cleanblkroot = root; 1377 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1378 } 1379 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1380 } 1381 1382 /* 1383 * Add the buffer to the sorted clean or dirty block list using a 1384 * splay tree algorithm. 1385 * 1386 * NOTE: xflags is passed as a constant, optimizing this inline function! 1387 */ 1388 static 1389 void 1390 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1391 { 1392 struct buf *root; 1393 1394 bp->b_xflags |= xflags; 1395 if (xflags & BX_VNDIRTY) { 1396 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1397 if (root == NULL) { 1398 bp->b_left = NULL; 1399 bp->b_right = NULL; 1400 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1401 } else if (bp->b_lblkno < root->b_lblkno || 1402 (bp->b_lblkno == root->b_lblkno && 1403 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1404 bp->b_left = root->b_left; 1405 bp->b_right = root; 1406 root->b_left = NULL; 1407 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1408 } else { 1409 bp->b_right = root->b_right; 1410 bp->b_left = root; 1411 root->b_right = NULL; 1412 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1413 root, bp, b_vnbufs); 1414 } 1415 vp->v_dirtyblkroot = bp; 1416 } else { 1417 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1418 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1419 if (root == NULL) { 1420 bp->b_left = NULL; 1421 bp->b_right = NULL; 1422 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1423 } else if (bp->b_lblkno < root->b_lblkno || 1424 (bp->b_lblkno == root->b_lblkno && 1425 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1426 bp->b_left = root->b_left; 1427 bp->b_right = root; 1428 root->b_left = NULL; 1429 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1430 } else { 1431 bp->b_right = root->b_right; 1432 bp->b_left = root; 1433 root->b_right = NULL; 1434 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1435 root, bp, b_vnbufs); 1436 } 1437 vp->v_cleanblkroot = bp; 1438 } 1439 } 1440 1441 #ifndef USE_BUFHASH 1442 1443 /* 1444 * Lookup a buffer using the splay tree. Note that we specifically avoid 1445 * shadow buffers used in background bitmap writes. 1446 * 1447 * This code isn't quite efficient as it could be because we are maintaining 1448 * two sorted lists and do not know which list the block resides in. 1449 */ 1450 struct buf * 1451 gbincore(struct vnode *vp, daddr_t lblkno) 1452 { 1453 struct buf *bp; 1454 1455 GIANT_REQUIRED; 1456 1457 bp = vp->v_cleanblkroot = buf_splay(lblkno, 0, vp->v_cleanblkroot); 1458 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1459 return(bp); 1460 bp = vp->v_dirtyblkroot = buf_splay(lblkno, 0, vp->v_dirtyblkroot); 1461 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1462 return(bp); 1463 return(NULL); 1464 } 1465 1466 #endif 1467 1468 /* 1469 * Associate a buffer with a vnode. 1470 */ 1471 void 1472 bgetvp(vp, bp) 1473 register struct vnode *vp; 1474 register struct buf *bp; 1475 { 1476 int s; 1477 1478 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1479 1480 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1481 ("bgetvp: bp already attached! %p", bp)); 1482 1483 vhold(vp); 1484 bp->b_vp = vp; 1485 bp->b_dev = vn_todev(vp); 1486 /* 1487 * Insert onto list for new vnode. 1488 */ 1489 s = splbio(); 1490 buf_vlist_add(bp, vp, BX_VNCLEAN); 1491 splx(s); 1492 } 1493 1494 /* 1495 * Disassociate a buffer from a vnode. 1496 */ 1497 void 1498 brelvp(bp) 1499 register struct buf *bp; 1500 { 1501 struct vnode *vp; 1502 int s; 1503 1504 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1505 1506 /* 1507 * Delete from old vnode list, if on one. 1508 */ 1509 vp = bp->b_vp; 1510 s = splbio(); 1511 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1512 buf_vlist_remove(bp); 1513 VI_LOCK(vp); 1514 if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1515 vp->v_iflag &= ~VI_ONWORKLST; 1516 LIST_REMOVE(vp, v_synclist); 1517 } 1518 VI_UNLOCK(vp); 1519 splx(s); 1520 bp->b_vp = (struct vnode *) 0; 1521 vdrop(vp); 1522 if (bp->b_object) 1523 bp->b_object = NULL; 1524 } 1525 1526 /* 1527 * Add an item to the syncer work queue. 1528 */ 1529 static void 1530 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1531 { 1532 int s, slot; 1533 1534 s = splbio(); 1535 ASSERT_VI_LOCKED(vp); 1536 1537 if (vp->v_iflag & VI_ONWORKLST) 1538 LIST_REMOVE(vp, v_synclist); 1539 else 1540 vp->v_iflag |= VI_ONWORKLST; 1541 1542 if (delay > syncer_maxdelay - 2) 1543 delay = syncer_maxdelay - 2; 1544 slot = (syncer_delayno + delay) & syncer_mask; 1545 1546 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1547 1548 splx(s); 1549 } 1550 1551 struct proc *updateproc; 1552 static void sched_sync(void); 1553 static struct kproc_desc up_kp = { 1554 "syncer", 1555 sched_sync, 1556 &updateproc 1557 }; 1558 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1559 1560 /* 1561 * System filesystem synchronizer daemon. 1562 */ 1563 void 1564 sched_sync(void) 1565 { 1566 struct synclist *slp; 1567 struct vnode *vp; 1568 struct mount *mp; 1569 long starttime; 1570 int s; 1571 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1572 1573 mtx_lock(&Giant); 1574 1575 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1576 SHUTDOWN_PRI_LAST); 1577 1578 for (;;) { 1579 kthread_suspend_check(td->td_proc); 1580 1581 starttime = time_second; 1582 1583 /* 1584 * Push files whose dirty time has expired. Be careful 1585 * of interrupt race on slp queue. 1586 */ 1587 s = splbio(); 1588 slp = &syncer_workitem_pending[syncer_delayno]; 1589 syncer_delayno += 1; 1590 if (syncer_delayno == syncer_maxdelay) 1591 syncer_delayno = 0; 1592 splx(s); 1593 1594 while ((vp = LIST_FIRST(slp)) != NULL) { 1595 if (VOP_ISLOCKED(vp, NULL) == 0 && 1596 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1597 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1598 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1599 VOP_UNLOCK(vp, 0, td); 1600 vn_finished_write(mp); 1601 } 1602 s = splbio(); 1603 if (LIST_FIRST(slp) == vp) { 1604 /* 1605 * Note: v_tag VT_VFS vps can remain on the 1606 * worklist too with no dirty blocks, but 1607 * since sync_fsync() moves it to a different 1608 * slot we are safe. 1609 */ 1610 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1611 !vn_isdisk(vp, NULL)) 1612 panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag); 1613 /* 1614 * Put us back on the worklist. The worklist 1615 * routine will remove us from our current 1616 * position and then add us back in at a later 1617 * position. 1618 */ 1619 VI_LOCK(vp); 1620 vn_syncer_add_to_worklist(vp, syncdelay); 1621 VI_UNLOCK(vp); 1622 } 1623 splx(s); 1624 } 1625 1626 /* 1627 * Do soft update processing. 1628 */ 1629 if (softdep_process_worklist_hook != NULL) 1630 (*softdep_process_worklist_hook)(NULL); 1631 1632 /* 1633 * The variable rushjob allows the kernel to speed up the 1634 * processing of the filesystem syncer process. A rushjob 1635 * value of N tells the filesystem syncer to process the next 1636 * N seconds worth of work on its queue ASAP. Currently rushjob 1637 * is used by the soft update code to speed up the filesystem 1638 * syncer process when the incore state is getting so far 1639 * ahead of the disk that the kernel memory pool is being 1640 * threatened with exhaustion. 1641 */ 1642 if (rushjob > 0) { 1643 rushjob -= 1; 1644 continue; 1645 } 1646 /* 1647 * If it has taken us less than a second to process the 1648 * current work, then wait. Otherwise start right over 1649 * again. We can still lose time if any single round 1650 * takes more than two seconds, but it does not really 1651 * matter as we are just trying to generally pace the 1652 * filesystem activity. 1653 */ 1654 if (time_second == starttime) 1655 tsleep(&lbolt, PPAUSE, "syncer", 0); 1656 } 1657 } 1658 1659 /* 1660 * Request the syncer daemon to speed up its work. 1661 * We never push it to speed up more than half of its 1662 * normal turn time, otherwise it could take over the cpu. 1663 * XXXKSE only one update? 1664 */ 1665 int 1666 speedup_syncer() 1667 { 1668 1669 mtx_lock_spin(&sched_lock); 1670 if (FIRST_THREAD_IN_PROC(updateproc)->td_wchan == &lbolt) /* XXXKSE */ 1671 setrunnable(FIRST_THREAD_IN_PROC(updateproc)); 1672 mtx_unlock_spin(&sched_lock); 1673 if (rushjob < syncdelay / 2) { 1674 rushjob += 1; 1675 stat_rush_requests += 1; 1676 return (1); 1677 } 1678 return(0); 1679 } 1680 1681 /* 1682 * Associate a p-buffer with a vnode. 1683 * 1684 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1685 * with the buffer. i.e. the bp has not been linked into the vnode or 1686 * ref-counted. 1687 */ 1688 void 1689 pbgetvp(vp, bp) 1690 register struct vnode *vp; 1691 register struct buf *bp; 1692 { 1693 1694 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1695 1696 bp->b_vp = vp; 1697 bp->b_flags |= B_PAGING; 1698 bp->b_dev = vn_todev(vp); 1699 } 1700 1701 /* 1702 * Disassociate a p-buffer from a vnode. 1703 */ 1704 void 1705 pbrelvp(bp) 1706 register struct buf *bp; 1707 { 1708 1709 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1710 1711 /* XXX REMOVE ME */ 1712 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1713 panic( 1714 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1715 bp, 1716 (int)bp->b_flags 1717 ); 1718 } 1719 bp->b_vp = (struct vnode *) 0; 1720 bp->b_flags &= ~B_PAGING; 1721 } 1722 1723 /* 1724 * Reassign a buffer from one vnode to another. 1725 * Used to assign file specific control information 1726 * (indirect blocks) to the vnode to which they belong. 1727 */ 1728 void 1729 reassignbuf(bp, newvp) 1730 register struct buf *bp; 1731 register struct vnode *newvp; 1732 { 1733 int delay; 1734 int s; 1735 1736 if (newvp == NULL) { 1737 printf("reassignbuf: NULL"); 1738 return; 1739 } 1740 ++reassignbufcalls; 1741 1742 /* 1743 * B_PAGING flagged buffers cannot be reassigned because their vp 1744 * is not fully linked in. 1745 */ 1746 if (bp->b_flags & B_PAGING) 1747 panic("cannot reassign paging buffer"); 1748 1749 s = splbio(); 1750 /* 1751 * Delete from old vnode list, if on one. 1752 */ 1753 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1754 buf_vlist_remove(bp); 1755 if (bp->b_vp != newvp) { 1756 vdrop(bp->b_vp); 1757 bp->b_vp = NULL; /* for clarification */ 1758 } 1759 } 1760 /* 1761 * If dirty, put on list of dirty buffers; otherwise insert onto list 1762 * of clean buffers. 1763 */ 1764 if (bp->b_flags & B_DELWRI) { 1765 VI_LOCK(newvp); 1766 if ((newvp->v_iflag & VI_ONWORKLST) == 0) { 1767 switch (newvp->v_type) { 1768 case VDIR: 1769 delay = dirdelay; 1770 break; 1771 case VCHR: 1772 if (newvp->v_rdev->si_mountpoint != NULL) { 1773 delay = metadelay; 1774 break; 1775 } 1776 /* fall through */ 1777 default: 1778 delay = filedelay; 1779 } 1780 vn_syncer_add_to_worklist(newvp, delay); 1781 } 1782 VI_UNLOCK(newvp); 1783 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1784 } else { 1785 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1786 1787 VI_LOCK(newvp); 1788 if ((newvp->v_iflag & VI_ONWORKLST) && 1789 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1790 newvp->v_iflag &= ~VI_ONWORKLST; 1791 LIST_REMOVE(newvp, v_synclist); 1792 } 1793 VI_UNLOCK(newvp); 1794 } 1795 if (bp->b_vp != newvp) { 1796 bp->b_vp = newvp; 1797 vhold(bp->b_vp); 1798 } 1799 splx(s); 1800 } 1801 1802 /* 1803 * Create a vnode for a device. 1804 * Used for mounting the root filesystem. 1805 */ 1806 int 1807 bdevvp(dev, vpp) 1808 dev_t dev; 1809 struct vnode **vpp; 1810 { 1811 register struct vnode *vp; 1812 struct vnode *nvp; 1813 int error; 1814 1815 if (dev == NODEV) { 1816 *vpp = NULLVP; 1817 return (ENXIO); 1818 } 1819 if (vfinddev(dev, VCHR, vpp)) 1820 return (0); 1821 error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp); 1822 if (error) { 1823 *vpp = NULLVP; 1824 return (error); 1825 } 1826 vp = nvp; 1827 vp->v_type = VCHR; 1828 addalias(vp, dev); 1829 *vpp = vp; 1830 return (0); 1831 } 1832 1833 /* 1834 * Add vnode to the alias list hung off the dev_t. 1835 * 1836 * The reason for this gunk is that multiple vnodes can reference 1837 * the same physical device, so checking vp->v_usecount to see 1838 * how many users there are is inadequate; the v_usecount for 1839 * the vnodes need to be accumulated. vcount() does that. 1840 */ 1841 struct vnode * 1842 addaliasu(nvp, nvp_rdev) 1843 struct vnode *nvp; 1844 udev_t nvp_rdev; 1845 { 1846 struct vnode *ovp; 1847 vop_t **ops; 1848 dev_t dev; 1849 1850 if (nvp->v_type == VBLK) 1851 return (nvp); 1852 if (nvp->v_type != VCHR) 1853 panic("addaliasu on non-special vnode"); 1854 dev = udev2dev(nvp_rdev, 0); 1855 /* 1856 * Check to see if we have a bdevvp vnode with no associated 1857 * filesystem. If so, we want to associate the filesystem of 1858 * the new newly instigated vnode with the bdevvp vnode and 1859 * discard the newly created vnode rather than leaving the 1860 * bdevvp vnode lying around with no associated filesystem. 1861 */ 1862 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 1863 addalias(nvp, dev); 1864 return (nvp); 1865 } 1866 /* 1867 * Discard unneeded vnode, but save its node specific data. 1868 * Note that if there is a lock, it is carried over in the 1869 * node specific data to the replacement vnode. 1870 */ 1871 vref(ovp); 1872 ovp->v_data = nvp->v_data; 1873 ovp->v_tag = nvp->v_tag; 1874 nvp->v_data = NULL; 1875 lockinit(&ovp->v_lock, PVFS, nvp->v_lock.lk_wmesg, 1876 nvp->v_lock.lk_timo, nvp->v_lock.lk_flags & LK_EXTFLG_MASK); 1877 if (nvp->v_vnlock) 1878 ovp->v_vnlock = &ovp->v_lock; 1879 ops = ovp->v_op; 1880 ovp->v_op = nvp->v_op; 1881 if (VOP_ISLOCKED(nvp, curthread)) { 1882 VOP_UNLOCK(nvp, 0, curthread); 1883 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1884 } 1885 nvp->v_op = ops; 1886 insmntque(ovp, nvp->v_mount); 1887 vrele(nvp); 1888 vgone(nvp); 1889 return (ovp); 1890 } 1891 1892 /* This is a local helper function that do the same as addaliasu, but for a 1893 * dev_t instead of an udev_t. */ 1894 static void 1895 addalias(nvp, dev) 1896 struct vnode *nvp; 1897 dev_t dev; 1898 { 1899 1900 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1901 nvp->v_rdev = dev; 1902 mtx_lock(&spechash_mtx); 1903 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1904 mtx_unlock(&spechash_mtx); 1905 } 1906 1907 /* 1908 * Grab a particular vnode from the free list, increment its 1909 * reference count and lock it. The vnode lock bit is set if the 1910 * vnode is being eliminated in vgone. The process is awakened 1911 * when the transition is completed, and an error returned to 1912 * indicate that the vnode is no longer usable (possibly having 1913 * been changed to a new filesystem type). 1914 */ 1915 int 1916 vget(vp, flags, td) 1917 register struct vnode *vp; 1918 int flags; 1919 struct thread *td; 1920 { 1921 int error; 1922 1923 /* 1924 * If the vnode is in the process of being cleaned out for 1925 * another use, we wait for the cleaning to finish and then 1926 * return failure. Cleaning is determined by checking that 1927 * the VI_XLOCK flag is set. 1928 */ 1929 if ((flags & LK_INTERLOCK) == 0) 1930 VI_LOCK(vp); 1931 if (vp->v_iflag & VI_XLOCK) { 1932 if (vp->v_vxproc == curthread) { 1933 #if 0 1934 /* this can now occur in normal operation */ 1935 log(LOG_INFO, "VXLOCK interlock avoided\n"); 1936 #endif 1937 } else { 1938 vp->v_iflag |= VI_XWANT; 1939 msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); 1940 mp_fixme("interlock not released."); 1941 return (ENOENT); 1942 } 1943 } 1944 1945 vp->v_usecount++; 1946 1947 if (VSHOULDBUSY(vp)) 1948 vbusy(vp); 1949 if (flags & LK_TYPE_MASK) { 1950 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1951 /* 1952 * must expand vrele here because we do not want 1953 * to call VOP_INACTIVE if the reference count 1954 * drops back to zero since it was never really 1955 * active. We must remove it from the free list 1956 * before sleeping so that multiple processes do 1957 * not try to recycle it. 1958 */ 1959 VI_LOCK(vp); 1960 vp->v_usecount--; 1961 if (VSHOULDFREE(vp)) 1962 vfree(vp); 1963 else 1964 vlruvp(vp); 1965 VI_UNLOCK(vp); 1966 } 1967 return (error); 1968 } 1969 VI_UNLOCK(vp); 1970 return (0); 1971 } 1972 1973 /* 1974 * Increase the reference count of a vnode. 1975 */ 1976 void 1977 vref(struct vnode *vp) 1978 { 1979 mtx_lock(&vp->v_interlock); 1980 vp->v_usecount++; 1981 mtx_unlock(&vp->v_interlock); 1982 } 1983 1984 /* 1985 * Vnode put/release. 1986 * If count drops to zero, call inactive routine and return to freelist. 1987 */ 1988 void 1989 vrele(vp) 1990 struct vnode *vp; 1991 { 1992 struct thread *td = curthread; /* XXX */ 1993 1994 KASSERT(vp != NULL, ("vrele: null vp")); 1995 1996 VI_LOCK(vp); 1997 1998 /* Skip this v_writecount check if we're going to panic below. */ 1999 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2000 ("vrele: missed vn_close")); 2001 2002 if (vp->v_usecount > 1) { 2003 2004 vp->v_usecount--; 2005 VI_UNLOCK(vp); 2006 2007 return; 2008 } 2009 2010 if (vp->v_usecount == 1) { 2011 vp->v_usecount--; 2012 /* 2013 * We must call VOP_INACTIVE with the node locked. 2014 * If we are doing a vput, the node is already locked, 2015 * but, in the case of vrele, we must explicitly lock 2016 * the vnode before calling VOP_INACTIVE. 2017 */ 2018 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) 2019 VOP_INACTIVE(vp, td); 2020 VI_LOCK(vp); 2021 if (VSHOULDFREE(vp)) 2022 vfree(vp); 2023 else 2024 vlruvp(vp); 2025 VI_UNLOCK(vp); 2026 2027 } else { 2028 #ifdef DIAGNOSTIC 2029 vprint("vrele: negative ref count", vp); 2030 VI_UNLOCK(vp); 2031 #endif 2032 panic("vrele: negative ref cnt"); 2033 } 2034 } 2035 2036 /* 2037 * Release an already locked vnode. This give the same effects as 2038 * unlock+vrele(), but takes less time and avoids releasing and 2039 * re-aquiring the lock (as vrele() aquires the lock internally.) 2040 */ 2041 void 2042 vput(vp) 2043 struct vnode *vp; 2044 { 2045 struct thread *td = curthread; /* XXX */ 2046 2047 GIANT_REQUIRED; 2048 2049 KASSERT(vp != NULL, ("vput: null vp")); 2050 mtx_lock(&vp->v_interlock); 2051 /* Skip this v_writecount check if we're going to panic below. */ 2052 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 2053 ("vput: missed vn_close")); 2054 2055 if (vp->v_usecount > 1) { 2056 vp->v_usecount--; 2057 VOP_UNLOCK(vp, LK_INTERLOCK, td); 2058 return; 2059 } 2060 2061 if (vp->v_usecount == 1) { 2062 vp->v_usecount--; 2063 /* 2064 * We must call VOP_INACTIVE with the node locked. 2065 * If we are doing a vput, the node is already locked, 2066 * so we just need to release the vnode mutex. 2067 */ 2068 VI_UNLOCK(vp); 2069 VOP_INACTIVE(vp, td); 2070 VI_LOCK(vp); 2071 if (VSHOULDFREE(vp)) 2072 vfree(vp); 2073 else 2074 vlruvp(vp); 2075 VI_UNLOCK(vp); 2076 2077 } else { 2078 #ifdef DIAGNOSTIC 2079 vprint("vput: negative ref count", vp); 2080 #endif 2081 panic("vput: negative ref cnt"); 2082 } 2083 } 2084 2085 /* 2086 * Somebody doesn't want the vnode recycled. 2087 */ 2088 void 2089 vhold(vp) 2090 register struct vnode *vp; 2091 { 2092 int s; 2093 2094 s = splbio(); 2095 vp->v_holdcnt++; 2096 VI_LOCK(vp); 2097 if (VSHOULDBUSY(vp)) 2098 vbusy(vp); 2099 VI_UNLOCK(vp); 2100 splx(s); 2101 } 2102 2103 /* 2104 * Note that there is one less who cares about this vnode. vdrop() is the 2105 * opposite of vhold(). 2106 */ 2107 void 2108 vdrop(vp) 2109 register struct vnode *vp; 2110 { 2111 int s; 2112 2113 s = splbio(); 2114 if (vp->v_holdcnt <= 0) 2115 panic("vdrop: holdcnt"); 2116 vp->v_holdcnt--; 2117 VI_LOCK(vp); 2118 if (VSHOULDFREE(vp)) 2119 vfree(vp); 2120 else 2121 vlruvp(vp); 2122 VI_UNLOCK(vp); 2123 splx(s); 2124 } 2125 2126 /* 2127 * Remove any vnodes in the vnode table belonging to mount point mp. 2128 * 2129 * If FORCECLOSE is not specified, there should not be any active ones, 2130 * return error if any are found (nb: this is a user error, not a 2131 * system error). If FORCECLOSE is specified, detach any active vnodes 2132 * that are found. 2133 * 2134 * If WRITECLOSE is set, only flush out regular file vnodes open for 2135 * writing. 2136 * 2137 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2138 * 2139 * `rootrefs' specifies the base reference count for the root vnode 2140 * of this filesystem. The root vnode is considered busy if its 2141 * v_usecount exceeds this value. On a successful return, vflush() 2142 * will call vrele() on the root vnode exactly rootrefs times. 2143 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2144 * be zero. 2145 */ 2146 #ifdef DIAGNOSTIC 2147 static int busyprt = 0; /* print out busy vnodes */ 2148 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 2149 #endif 2150 2151 int 2152 vflush(mp, rootrefs, flags) 2153 struct mount *mp; 2154 int rootrefs; 2155 int flags; 2156 { 2157 struct thread *td = curthread; /* XXX */ 2158 struct vnode *vp, *nvp, *rootvp = NULL; 2159 struct vattr vattr; 2160 int busy = 0, error; 2161 2162 if (rootrefs > 0) { 2163 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2164 ("vflush: bad args")); 2165 /* 2166 * Get the filesystem root vnode. We can vput() it 2167 * immediately, since with rootrefs > 0, it won't go away. 2168 */ 2169 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2170 return (error); 2171 vput(rootvp); 2172 2173 } 2174 mtx_lock(&mntvnode_mtx); 2175 loop: 2176 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2177 /* 2178 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2179 * Start over if it has (it won't be on the list anymore). 2180 */ 2181 if (vp->v_mount != mp) 2182 goto loop; 2183 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2184 2185 mtx_unlock(&mntvnode_mtx); 2186 VI_LOCK(vp); 2187 /* 2188 * Skip over a vnodes marked VV_SYSTEM. 2189 */ 2190 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2191 VI_UNLOCK(vp); 2192 mtx_lock(&mntvnode_mtx); 2193 continue; 2194 } 2195 /* 2196 * If WRITECLOSE is set, flush out unlinked but still open 2197 * files (even if open only for reading) and regular file 2198 * vnodes open for writing. 2199 */ 2200 mp_fixme("Getattr called with interlock held!"); 2201 if ((flags & WRITECLOSE) && 2202 (vp->v_type == VNON || 2203 (VOP_GETATTR(vp, &vattr, td->td_ucred, td) == 0 && 2204 vattr.va_nlink > 0)) && 2205 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2206 mtx_unlock(&vp->v_interlock); 2207 mtx_lock(&mntvnode_mtx); 2208 continue; 2209 } 2210 2211 /* 2212 * With v_usecount == 0, all we need to do is clear out the 2213 * vnode data structures and we are done. 2214 */ 2215 if (vp->v_usecount == 0) { 2216 vgonel(vp, td); 2217 mtx_lock(&mntvnode_mtx); 2218 continue; 2219 } 2220 2221 /* 2222 * If FORCECLOSE is set, forcibly close the vnode. For block 2223 * or character devices, revert to an anonymous device. For 2224 * all other files, just kill them. 2225 */ 2226 if (flags & FORCECLOSE) { 2227 if (vp->v_type != VCHR) { 2228 vgonel(vp, td); 2229 } else { 2230 vclean(vp, 0, td); 2231 VI_UNLOCK(vp); 2232 vp->v_op = spec_vnodeop_p; 2233 insmntque(vp, (struct mount *) 0); 2234 } 2235 mtx_lock(&mntvnode_mtx); 2236 continue; 2237 } 2238 #ifdef DIAGNOSTIC 2239 if (busyprt) 2240 vprint("vflush: busy vnode", vp); 2241 #endif 2242 VI_UNLOCK(vp); 2243 mtx_lock(&mntvnode_mtx); 2244 busy++; 2245 } 2246 mtx_unlock(&mntvnode_mtx); 2247 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2248 /* 2249 * If just the root vnode is busy, and if its refcount 2250 * is equal to `rootrefs', then go ahead and kill it. 2251 */ 2252 mtx_lock(&rootvp->v_interlock); 2253 KASSERT(busy > 0, ("vflush: not busy")); 2254 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2255 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2256 vgonel(rootvp, td); 2257 busy = 0; 2258 } else 2259 mtx_unlock(&rootvp->v_interlock); 2260 } 2261 if (busy) 2262 return (EBUSY); 2263 for (; rootrefs > 0; rootrefs--) 2264 vrele(rootvp); 2265 return (0); 2266 } 2267 2268 /* 2269 * This moves a now (likely recyclable) vnode to the end of the 2270 * mountlist. XXX However, it is temporarily disabled until we 2271 * can clean up ffs_sync() and friends, which have loop restart 2272 * conditions which this code causes to operate O(N^2). 2273 */ 2274 static void 2275 vlruvp(struct vnode *vp) 2276 { 2277 #if 0 2278 struct mount *mp; 2279 2280 if ((mp = vp->v_mount) != NULL) { 2281 mtx_lock(&mntvnode_mtx); 2282 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2283 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2284 mtx_unlock(&mntvnode_mtx); 2285 } 2286 #endif 2287 } 2288 2289 /* 2290 * Disassociate the underlying filesystem from a vnode. 2291 */ 2292 static void 2293 vclean(vp, flags, td) 2294 struct vnode *vp; 2295 int flags; 2296 struct thread *td; 2297 { 2298 int active; 2299 2300 ASSERT_VI_LOCKED(vp); 2301 /* 2302 * Check to see if the vnode is in use. If so we have to reference it 2303 * before we clean it out so that its count cannot fall to zero and 2304 * generate a race against ourselves to recycle it. 2305 */ 2306 if ((active = vp->v_usecount)) 2307 vp->v_usecount++; 2308 2309 /* 2310 * Prevent the vnode from being recycled or brought into use while we 2311 * clean it out. 2312 */ 2313 if (vp->v_iflag & VI_XLOCK) 2314 panic("vclean: deadlock"); 2315 vp->v_iflag |= VI_XLOCK; 2316 vp->v_vxproc = curthread; 2317 /* 2318 * Even if the count is zero, the VOP_INACTIVE routine may still 2319 * have the object locked while it cleans it out. The VOP_LOCK 2320 * ensures that the VOP_INACTIVE routine is done with its work. 2321 * For active vnodes, it ensures that no other activity can 2322 * occur while the underlying object is being cleaned out. 2323 */ 2324 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2325 2326 /* 2327 * Clean out any buffers associated with the vnode. 2328 * If the flush fails, just toss the buffers. 2329 */ 2330 if (flags & DOCLOSE) { 2331 if (TAILQ_FIRST(&vp->v_dirtyblkhd) != NULL) 2332 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2333 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2334 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2335 } 2336 2337 VOP_DESTROYVOBJECT(vp); 2338 2339 /* 2340 * Any other processes trying to obtain this lock must first 2341 * wait for VXLOCK to clear, then call the new lock operation. 2342 */ 2343 VOP_UNLOCK(vp, 0, td); 2344 2345 /* 2346 * If purging an active vnode, it must be closed and 2347 * deactivated before being reclaimed. Note that the 2348 * VOP_INACTIVE will unlock the vnode. 2349 */ 2350 if (active) { 2351 if (flags & DOCLOSE) 2352 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2353 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2354 panic("vclean: cannot relock."); 2355 VOP_INACTIVE(vp, td); 2356 } 2357 2358 /* 2359 * Reclaim the vnode. 2360 */ 2361 if (VOP_RECLAIM(vp, td)) 2362 panic("vclean: cannot reclaim"); 2363 2364 if (active) { 2365 /* 2366 * Inline copy of vrele() since VOP_INACTIVE 2367 * has already been called. 2368 */ 2369 VI_LOCK(vp); 2370 if (--vp->v_usecount <= 0) { 2371 #ifdef DIAGNOSTIC 2372 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2373 vprint("vclean: bad ref count", vp); 2374 panic("vclean: ref cnt"); 2375 } 2376 #endif 2377 vfree(vp); 2378 } 2379 VI_UNLOCK(vp); 2380 } 2381 2382 cache_purge(vp); 2383 vp->v_vnlock = NULL; 2384 lockdestroy(&vp->v_lock); 2385 2386 VI_LOCK(vp); 2387 if (VSHOULDFREE(vp)) 2388 vfree(vp); 2389 2390 /* 2391 * Done with purge, notify sleepers of the grim news. 2392 */ 2393 vp->v_op = dead_vnodeop_p; 2394 if (vp->v_pollinfo != NULL) 2395 vn_pollgone(vp); 2396 vp->v_tag = VT_NON; 2397 vp->v_iflag &= ~VI_XLOCK; 2398 vp->v_vxproc = NULL; 2399 if (vp->v_iflag & VI_XWANT) { 2400 vp->v_iflag &= ~VI_XWANT; 2401 wakeup(vp); 2402 } 2403 } 2404 2405 /* 2406 * Eliminate all activity associated with the requested vnode 2407 * and with all vnodes aliased to the requested vnode. 2408 */ 2409 int 2410 vop_revoke(ap) 2411 struct vop_revoke_args /* { 2412 struct vnode *a_vp; 2413 int a_flags; 2414 } */ *ap; 2415 { 2416 struct vnode *vp, *vq; 2417 dev_t dev; 2418 2419 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2420 2421 vp = ap->a_vp; 2422 VI_LOCK(vp); 2423 /* 2424 * If a vgone (or vclean) is already in progress, 2425 * wait until it is done and return. 2426 */ 2427 if (vp->v_iflag & VI_XLOCK) { 2428 vp->v_iflag |= VI_XWANT; 2429 msleep(vp, VI_MTX(vp), PINOD | PDROP, 2430 "vop_revokeall", 0); 2431 VI_UNLOCK(vp); 2432 return (0); 2433 } 2434 VI_UNLOCK(vp); 2435 dev = vp->v_rdev; 2436 for (;;) { 2437 mtx_lock(&spechash_mtx); 2438 vq = SLIST_FIRST(&dev->si_hlist); 2439 mtx_unlock(&spechash_mtx); 2440 if (!vq) 2441 break; 2442 vgone(vq); 2443 } 2444 return (0); 2445 } 2446 2447 /* 2448 * Recycle an unused vnode to the front of the free list. 2449 * Release the passed interlock if the vnode will be recycled. 2450 */ 2451 int 2452 vrecycle(vp, inter_lkp, td) 2453 struct vnode *vp; 2454 struct mtx *inter_lkp; 2455 struct thread *td; 2456 { 2457 2458 mtx_lock(&vp->v_interlock); 2459 if (vp->v_usecount == 0) { 2460 if (inter_lkp) { 2461 mtx_unlock(inter_lkp); 2462 } 2463 vgonel(vp, td); 2464 return (1); 2465 } 2466 mtx_unlock(&vp->v_interlock); 2467 return (0); 2468 } 2469 2470 /* 2471 * Eliminate all activity associated with a vnode 2472 * in preparation for reuse. 2473 */ 2474 void 2475 vgone(vp) 2476 register struct vnode *vp; 2477 { 2478 struct thread *td = curthread; /* XXX */ 2479 2480 VI_LOCK(vp); 2481 vgonel(vp, td); 2482 } 2483 2484 /* 2485 * vgone, with the vp interlock held. 2486 */ 2487 void 2488 vgonel(vp, td) 2489 struct vnode *vp; 2490 struct thread *td; 2491 { 2492 int s; 2493 2494 /* 2495 * If a vgone (or vclean) is already in progress, 2496 * wait until it is done and return. 2497 */ 2498 ASSERT_VI_LOCKED(vp); 2499 if (vp->v_iflag & VI_XLOCK) { 2500 vp->v_iflag |= VI_XWANT; 2501 VI_UNLOCK(vp); 2502 tsleep(vp, PINOD | PDROP, "vgone", 0); 2503 return; 2504 } 2505 2506 /* 2507 * Clean out the filesystem specific data. 2508 */ 2509 vclean(vp, DOCLOSE, td); 2510 VI_UNLOCK(vp); 2511 2512 /* 2513 * Delete from old mount point vnode list, if on one. 2514 */ 2515 if (vp->v_mount != NULL) 2516 insmntque(vp, (struct mount *)0); 2517 /* 2518 * If special device, remove it from special device alias list 2519 * if it is on one. 2520 */ 2521 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2522 mtx_lock(&spechash_mtx); 2523 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2524 freedev(vp->v_rdev); 2525 mtx_unlock(&spechash_mtx); 2526 vp->v_rdev = NULL; 2527 } 2528 2529 /* 2530 * If it is on the freelist and not already at the head, 2531 * move it to the head of the list. The test of the 2532 * VDOOMED flag and the reference count of zero is because 2533 * it will be removed from the free list by getnewvnode, 2534 * but will not have its reference count incremented until 2535 * after calling vgone. If the reference count were 2536 * incremented first, vgone would (incorrectly) try to 2537 * close the previous instance of the underlying object. 2538 */ 2539 VI_LOCK(vp); 2540 if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { 2541 s = splbio(); 2542 mtx_lock(&vnode_free_list_mtx); 2543 if (vp->v_iflag & VI_FREE) { 2544 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2545 } else { 2546 vp->v_iflag |= VI_FREE; 2547 freevnodes++; 2548 } 2549 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2550 mtx_unlock(&vnode_free_list_mtx); 2551 splx(s); 2552 } 2553 2554 vp->v_type = VBAD; 2555 VI_UNLOCK(vp); 2556 } 2557 2558 /* 2559 * Lookup a vnode by device number. 2560 */ 2561 int 2562 vfinddev(dev, type, vpp) 2563 dev_t dev; 2564 enum vtype type; 2565 struct vnode **vpp; 2566 { 2567 struct vnode *vp; 2568 2569 mtx_lock(&spechash_mtx); 2570 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2571 if (type == vp->v_type) { 2572 *vpp = vp; 2573 mtx_unlock(&spechash_mtx); 2574 return (1); 2575 } 2576 } 2577 mtx_unlock(&spechash_mtx); 2578 return (0); 2579 } 2580 2581 /* 2582 * Calculate the total number of references to a special device. 2583 */ 2584 int 2585 vcount(vp) 2586 struct vnode *vp; 2587 { 2588 struct vnode *vq; 2589 int count; 2590 2591 count = 0; 2592 mtx_lock(&spechash_mtx); 2593 SLIST_FOREACH(vq, &vp->v_rdev->si_hlist, v_specnext) 2594 count += vq->v_usecount; 2595 mtx_unlock(&spechash_mtx); 2596 return (count); 2597 } 2598 2599 /* 2600 * Same as above, but using the dev_t as argument 2601 */ 2602 int 2603 count_dev(dev) 2604 dev_t dev; 2605 { 2606 struct vnode *vp; 2607 2608 vp = SLIST_FIRST(&dev->si_hlist); 2609 if (vp == NULL) 2610 return (0); 2611 return(vcount(vp)); 2612 } 2613 2614 /* 2615 * Print out a description of a vnode. 2616 */ 2617 static char *typename[] = 2618 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2619 2620 void 2621 vprint(label, vp) 2622 char *label; 2623 struct vnode *vp; 2624 { 2625 char buf[96]; 2626 2627 if (label != NULL) 2628 printf("%s: %p: ", label, (void *)vp); 2629 else 2630 printf("%p: ", (void *)vp); 2631 printf("type %s, usecount %d, writecount %d, refcount %d,", 2632 typename[vp->v_type], vp->v_usecount, vp->v_writecount, 2633 vp->v_holdcnt); 2634 buf[0] = '\0'; 2635 if (vp->v_vflag & VV_ROOT) 2636 strcat(buf, "|VV_ROOT"); 2637 if (vp->v_vflag & VV_TEXT) 2638 strcat(buf, "|VV_TEXT"); 2639 if (vp->v_vflag & VV_SYSTEM) 2640 strcat(buf, "|VV_SYSTEM"); 2641 if (vp->v_iflag & VI_XLOCK) 2642 strcat(buf, "|VI_XLOCK"); 2643 if (vp->v_iflag & VI_XWANT) 2644 strcat(buf, "|VI_XWANT"); 2645 if (vp->v_iflag & VI_BWAIT) 2646 strcat(buf, "|VI_BWAIT"); 2647 if (vp->v_iflag & VI_DOOMED) 2648 strcat(buf, "|VI_DOOMED"); 2649 if (vp->v_iflag & VI_FREE) 2650 strcat(buf, "|VI_FREE"); 2651 if (vp->v_vflag & VV_OBJBUF) 2652 strcat(buf, "|VV_OBJBUF"); 2653 if (buf[0] != '\0') 2654 printf(" flags (%s)", &buf[1]); 2655 if (vp->v_data == NULL) { 2656 printf("\n"); 2657 } else { 2658 printf("\n\t"); 2659 VOP_PRINT(vp); 2660 } 2661 } 2662 2663 #ifdef DDB 2664 #include <ddb/ddb.h> 2665 /* 2666 * List all of the locked vnodes in the system. 2667 * Called when debugging the kernel. 2668 */ 2669 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2670 { 2671 struct thread *td = curthread; /* XXX */ 2672 struct mount *mp, *nmp; 2673 struct vnode *vp; 2674 2675 printf("Locked vnodes\n"); 2676 mtx_lock(&mountlist_mtx); 2677 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2678 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2679 nmp = TAILQ_NEXT(mp, mnt_list); 2680 continue; 2681 } 2682 mtx_lock(&mntvnode_mtx); 2683 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2684 if (VOP_ISLOCKED(vp, NULL)) 2685 vprint((char *)0, vp); 2686 } 2687 mtx_unlock(&mntvnode_mtx); 2688 mtx_lock(&mountlist_mtx); 2689 nmp = TAILQ_NEXT(mp, mnt_list); 2690 vfs_unbusy(mp, td); 2691 } 2692 mtx_unlock(&mountlist_mtx); 2693 } 2694 #endif 2695 2696 /* 2697 * Fill in a struct xvfsconf based on a struct vfsconf. 2698 */ 2699 static void 2700 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 2701 { 2702 2703 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 2704 xvfsp->vfc_typenum = vfsp->vfc_typenum; 2705 xvfsp->vfc_refcount = vfsp->vfc_refcount; 2706 xvfsp->vfc_flags = vfsp->vfc_flags; 2707 /* 2708 * These are unused in userland, we keep them 2709 * to not break binary compatibility. 2710 */ 2711 xvfsp->vfc_vfsops = NULL; 2712 xvfsp->vfc_next = NULL; 2713 } 2714 2715 static int 2716 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 2717 { 2718 struct vfsconf *vfsp; 2719 struct xvfsconf *xvfsp; 2720 int cnt, error, i; 2721 2722 cnt = 0; 2723 for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) 2724 cnt++; 2725 xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); 2726 /* 2727 * Handle the race that we will have here when struct vfsconf 2728 * will be locked down by using both cnt and checking vfc_next 2729 * against NULL to determine the end of the loop. The race will 2730 * happen because we will have to unlock before calling malloc(). 2731 * We are protected by Giant for now. 2732 */ 2733 i = 0; 2734 for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { 2735 vfsconf2x(vfsp, xvfsp + i); 2736 i++; 2737 } 2738 error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); 2739 free(xvfsp, M_TEMP); 2740 return (error); 2741 } 2742 2743 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, 2744 "S,xvfsconf", "List of all configured filesystems"); 2745 2746 /* 2747 * Top level filesystem related information gathering. 2748 */ 2749 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2750 2751 static int 2752 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2753 { 2754 int *name = (int *)arg1 - 1; /* XXX */ 2755 u_int namelen = arg2 + 1; /* XXX */ 2756 struct vfsconf *vfsp; 2757 struct xvfsconf xvfsp; 2758 2759 printf("WARNING: userland calling deprecated sysctl, " 2760 "please rebuild world\n"); 2761 2762 #if 1 || defined(COMPAT_PRELITE2) 2763 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2764 if (namelen == 1) 2765 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2766 #endif 2767 2768 switch (name[1]) { 2769 case VFS_MAXTYPENUM: 2770 if (namelen != 2) 2771 return (ENOTDIR); 2772 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2773 case VFS_CONF: 2774 if (namelen != 3) 2775 return (ENOTDIR); /* overloaded */ 2776 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2777 if (vfsp->vfc_typenum == name[2]) 2778 break; 2779 if (vfsp == NULL) 2780 return (EOPNOTSUPP); 2781 vfsconf2x(vfsp, &xvfsp); 2782 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 2783 } 2784 return (EOPNOTSUPP); 2785 } 2786 2787 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, 2788 "Generic filesystem"); 2789 2790 #if 1 || defined(COMPAT_PRELITE2) 2791 2792 static int 2793 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2794 { 2795 int error; 2796 struct vfsconf *vfsp; 2797 struct ovfsconf ovfs; 2798 2799 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 2800 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2801 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2802 ovfs.vfc_index = vfsp->vfc_typenum; 2803 ovfs.vfc_refcount = vfsp->vfc_refcount; 2804 ovfs.vfc_flags = vfsp->vfc_flags; 2805 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2806 if (error) 2807 return error; 2808 } 2809 return 0; 2810 } 2811 2812 #endif /* 1 || COMPAT_PRELITE2 */ 2813 2814 #define KINFO_VNODESLOP 10 2815 /* 2816 * Dump vnode list (via sysctl). 2817 */ 2818 /* ARGSUSED */ 2819 static int 2820 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2821 { 2822 struct xvnode *xvn; 2823 struct thread *td = req->td; 2824 struct mount *mp; 2825 struct vnode *vp; 2826 int error, len, n; 2827 2828 /* 2829 * Stale numvnodes access is not fatal here. 2830 */ 2831 req->lock = 0; 2832 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 2833 if (!req->oldptr) 2834 /* Make an estimate */ 2835 return (SYSCTL_OUT(req, 0, len)); 2836 2837 sysctl_wire_old_buffer(req, 0); 2838 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 2839 n = 0; 2840 mtx_lock(&mountlist_mtx); 2841 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2842 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) 2843 continue; 2844 mtx_lock(&mntvnode_mtx); 2845 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2846 if (n == len) 2847 break; 2848 vref(vp); 2849 xvn[n].xv_size = sizeof *xvn; 2850 xvn[n].xv_vnode = vp; 2851 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 2852 XV_COPY(usecount); 2853 XV_COPY(writecount); 2854 XV_COPY(holdcnt); 2855 XV_COPY(id); 2856 XV_COPY(mount); 2857 XV_COPY(numoutput); 2858 XV_COPY(type); 2859 #undef XV_COPY 2860 xvn[n].xv_flag = vp->v_vflag; 2861 2862 switch (vp->v_type) { 2863 case VREG: 2864 case VDIR: 2865 case VLNK: 2866 xvn[n].xv_dev = vp->v_cachedfs; 2867 xvn[n].xv_ino = vp->v_cachedid; 2868 break; 2869 case VBLK: 2870 case VCHR: 2871 if (vp->v_rdev == NULL) { 2872 vrele(vp); 2873 continue; 2874 } 2875 xvn[n].xv_dev = dev2udev(vp->v_rdev); 2876 break; 2877 case VSOCK: 2878 xvn[n].xv_socket = vp->v_socket; 2879 break; 2880 case VFIFO: 2881 xvn[n].xv_fifo = vp->v_fifoinfo; 2882 break; 2883 case VNON: 2884 case VBAD: 2885 default: 2886 /* shouldn't happen? */ 2887 vrele(vp); 2888 continue; 2889 } 2890 vrele(vp); 2891 ++n; 2892 } 2893 mtx_unlock(&mntvnode_mtx); 2894 mtx_lock(&mountlist_mtx); 2895 vfs_unbusy(mp, td); 2896 if (n == len) 2897 break; 2898 } 2899 mtx_unlock(&mountlist_mtx); 2900 2901 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 2902 free(xvn, M_TEMP); 2903 return (error); 2904 } 2905 2906 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2907 0, 0, sysctl_vnode, "S,xvnode", ""); 2908 2909 /* 2910 * Check to see if a filesystem is mounted on a block device. 2911 */ 2912 int 2913 vfs_mountedon(vp) 2914 struct vnode *vp; 2915 { 2916 2917 if (vp->v_rdev->si_mountpoint != NULL) 2918 return (EBUSY); 2919 return (0); 2920 } 2921 2922 /* 2923 * Unmount all filesystems. The list is traversed in reverse order 2924 * of mounting to avoid dependencies. 2925 */ 2926 void 2927 vfs_unmountall() 2928 { 2929 struct mount *mp; 2930 struct thread *td; 2931 int error; 2932 2933 if (curthread != NULL) 2934 td = curthread; 2935 else 2936 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 2937 /* 2938 * Since this only runs when rebooting, it is not interlocked. 2939 */ 2940 while(!TAILQ_EMPTY(&mountlist)) { 2941 mp = TAILQ_LAST(&mountlist, mntlist); 2942 error = dounmount(mp, MNT_FORCE, td); 2943 if (error) { 2944 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2945 printf("unmount of %s failed (", 2946 mp->mnt_stat.f_mntonname); 2947 if (error == EBUSY) 2948 printf("BUSY)\n"); 2949 else 2950 printf("%d)\n", error); 2951 } else { 2952 /* The unmount has removed mp from the mountlist */ 2953 } 2954 } 2955 } 2956 2957 /* 2958 * perform msync on all vnodes under a mount point 2959 * the mount point must be locked. 2960 */ 2961 void 2962 vfs_msync(struct mount *mp, int flags) 2963 { 2964 struct vnode *vp, *nvp; 2965 struct vm_object *obj; 2966 int tries; 2967 2968 GIANT_REQUIRED; 2969 2970 tries = 5; 2971 mtx_lock(&mntvnode_mtx); 2972 loop: 2973 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 2974 if (vp->v_mount != mp) { 2975 if (--tries > 0) 2976 goto loop; 2977 break; 2978 } 2979 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2980 2981 mp_fixme("What locks do we need here?"); 2982 if (vp->v_iflag & VI_XLOCK) /* XXX: what if MNT_WAIT? */ 2983 continue; 2984 2985 if (vp->v_vflag & VV_NOSYNC) /* unlinked, skip it */ 2986 continue; 2987 2988 if ((vp->v_iflag & VI_OBJDIRTY) && 2989 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2990 mtx_unlock(&mntvnode_mtx); 2991 if (!vget(vp, 2992 LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curthread)) { 2993 if (VOP_GETVOBJECT(vp, &obj) == 0) { 2994 vm_object_page_clean(obj, 0, 0, 2995 flags == MNT_WAIT ? 2996 OBJPC_SYNC : OBJPC_NOSYNC); 2997 } 2998 vput(vp); 2999 } 3000 mtx_lock(&mntvnode_mtx); 3001 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 3002 if (--tries > 0) 3003 goto loop; 3004 break; 3005 } 3006 } 3007 } 3008 mtx_unlock(&mntvnode_mtx); 3009 } 3010 3011 /* 3012 * Create the VM object needed for VMIO and mmap support. This 3013 * is done for all VREG files in the system. Some filesystems might 3014 * afford the additional metadata buffering capability of the 3015 * VMIO code by making the device node be VMIO mode also. 3016 * 3017 * vp must be locked when vfs_object_create is called. 3018 */ 3019 int 3020 vfs_object_create(vp, td, cred) 3021 struct vnode *vp; 3022 struct thread *td; 3023 struct ucred *cred; 3024 { 3025 GIANT_REQUIRED; 3026 return (VOP_CREATEVOBJECT(vp, cred, td)); 3027 } 3028 3029 /* 3030 * Mark a vnode as free, putting it up for recycling. 3031 */ 3032 void 3033 vfree(vp) 3034 struct vnode *vp; 3035 { 3036 int s; 3037 3038 ASSERT_VI_LOCKED(vp); 3039 s = splbio(); 3040 mtx_lock(&vnode_free_list_mtx); 3041 KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); 3042 if (vp->v_iflag & VI_AGE) { 3043 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3044 } else { 3045 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3046 } 3047 freevnodes++; 3048 mtx_unlock(&vnode_free_list_mtx); 3049 vp->v_iflag &= ~VI_AGE; 3050 vp->v_iflag |= VI_FREE; 3051 splx(s); 3052 } 3053 3054 /* 3055 * Opposite of vfree() - mark a vnode as in use. 3056 */ 3057 void 3058 vbusy(vp) 3059 struct vnode *vp; 3060 { 3061 int s; 3062 3063 s = splbio(); 3064 ASSERT_VI_LOCKED(vp); 3065 mtx_lock(&vnode_free_list_mtx); 3066 KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); 3067 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3068 freevnodes--; 3069 mtx_unlock(&vnode_free_list_mtx); 3070 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3071 splx(s); 3072 } 3073 3074 /* 3075 * Record a process's interest in events which might happen to 3076 * a vnode. Because poll uses the historic select-style interface 3077 * internally, this routine serves as both the ``check for any 3078 * pending events'' and the ``record my interest in future events'' 3079 * functions. (These are done together, while the lock is held, 3080 * to avoid race conditions.) 3081 */ 3082 int 3083 vn_pollrecord(vp, td, events) 3084 struct vnode *vp; 3085 struct thread *td; 3086 short events; 3087 { 3088 3089 if (vp->v_pollinfo == NULL) 3090 v_addpollinfo(vp); 3091 mtx_lock(&vp->v_pollinfo->vpi_lock); 3092 if (vp->v_pollinfo->vpi_revents & events) { 3093 /* 3094 * This leaves events we are not interested 3095 * in available for the other process which 3096 * which presumably had requested them 3097 * (otherwise they would never have been 3098 * recorded). 3099 */ 3100 events &= vp->v_pollinfo->vpi_revents; 3101 vp->v_pollinfo->vpi_revents &= ~events; 3102 3103 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3104 return events; 3105 } 3106 vp->v_pollinfo->vpi_events |= events; 3107 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3108 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3109 return 0; 3110 } 3111 3112 /* 3113 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 3114 * it is possible for us to miss an event due to race conditions, but 3115 * that condition is expected to be rare, so for the moment it is the 3116 * preferred interface. 3117 */ 3118 void 3119 vn_pollevent(vp, events) 3120 struct vnode *vp; 3121 short events; 3122 { 3123 3124 if (vp->v_pollinfo == NULL) 3125 v_addpollinfo(vp); 3126 mtx_lock(&vp->v_pollinfo->vpi_lock); 3127 if (vp->v_pollinfo->vpi_events & events) { 3128 /* 3129 * We clear vpi_events so that we don't 3130 * call selwakeup() twice if two events are 3131 * posted before the polling process(es) is 3132 * awakened. This also ensures that we take at 3133 * most one selwakeup() if the polling process 3134 * is no longer interested. However, it does 3135 * mean that only one event can be noticed at 3136 * a time. (Perhaps we should only clear those 3137 * event bits which we note?) XXX 3138 */ 3139 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 3140 vp->v_pollinfo->vpi_revents |= events; 3141 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3142 } 3143 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3144 } 3145 3146 /* 3147 * Wake up anyone polling on vp because it is being revoked. 3148 * This depends on dead_poll() returning POLLHUP for correct 3149 * behavior. 3150 */ 3151 void 3152 vn_pollgone(vp) 3153 struct vnode *vp; 3154 { 3155 3156 mtx_lock(&vp->v_pollinfo->vpi_lock); 3157 VN_KNOTE(vp, NOTE_REVOKE); 3158 if (vp->v_pollinfo->vpi_events) { 3159 vp->v_pollinfo->vpi_events = 0; 3160 selwakeup(&vp->v_pollinfo->vpi_selinfo); 3161 } 3162 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3163 } 3164 3165 3166 3167 /* 3168 * Routine to create and manage a filesystem syncer vnode. 3169 */ 3170 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3171 static int sync_fsync(struct vop_fsync_args *); 3172 static int sync_inactive(struct vop_inactive_args *); 3173 static int sync_reclaim(struct vop_reclaim_args *); 3174 static int sync_print(struct vop_print_args *); 3175 3176 static vop_t **sync_vnodeop_p; 3177 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 3178 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 3179 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 3180 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 3181 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 3182 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 3183 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 3184 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 3185 { &vop_print_desc, (vop_t *) sync_print }, /* print */ 3186 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 3187 { NULL, NULL } 3188 }; 3189 static struct vnodeopv_desc sync_vnodeop_opv_desc = 3190 { &sync_vnodeop_p, sync_vnodeop_entries }; 3191 3192 VNODEOP_SET(sync_vnodeop_opv_desc); 3193 3194 /* 3195 * Create a new filesystem syncer vnode for the specified mount point. 3196 */ 3197 int 3198 vfs_allocate_syncvnode(mp) 3199 struct mount *mp; 3200 { 3201 struct vnode *vp; 3202 static long start, incr, next; 3203 int error; 3204 3205 /* Allocate a new vnode */ 3206 if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) { 3207 mp->mnt_syncer = NULL; 3208 return (error); 3209 } 3210 vp->v_type = VNON; 3211 /* 3212 * Place the vnode onto the syncer worklist. We attempt to 3213 * scatter them about on the list so that they will go off 3214 * at evenly distributed times even if all the filesystems 3215 * are mounted at once. 3216 */ 3217 next += incr; 3218 if (next == 0 || next > syncer_maxdelay) { 3219 start /= 2; 3220 incr /= 2; 3221 if (start == 0) { 3222 start = syncer_maxdelay / 2; 3223 incr = syncer_maxdelay; 3224 } 3225 next = start; 3226 } 3227 VI_LOCK(vp); 3228 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 3229 VI_UNLOCK(vp); 3230 mp->mnt_syncer = vp; 3231 return (0); 3232 } 3233 3234 /* 3235 * Do a lazy sync of the filesystem. 3236 */ 3237 static int 3238 sync_fsync(ap) 3239 struct vop_fsync_args /* { 3240 struct vnode *a_vp; 3241 struct ucred *a_cred; 3242 int a_waitfor; 3243 struct thread *a_td; 3244 } */ *ap; 3245 { 3246 struct vnode *syncvp = ap->a_vp; 3247 struct mount *mp = syncvp->v_mount; 3248 struct thread *td = ap->a_td; 3249 int asyncflag; 3250 3251 /* 3252 * We only need to do something if this is a lazy evaluation. 3253 */ 3254 if (ap->a_waitfor != MNT_LAZY) 3255 return (0); 3256 3257 /* 3258 * Move ourselves to the back of the sync list. 3259 */ 3260 VI_LOCK(syncvp); 3261 vn_syncer_add_to_worklist(syncvp, syncdelay); 3262 VI_UNLOCK(syncvp); 3263 3264 /* 3265 * Walk the list of vnodes pushing all that are dirty and 3266 * not already on the sync list. 3267 */ 3268 mtx_lock(&mountlist_mtx); 3269 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3270 mtx_unlock(&mountlist_mtx); 3271 return (0); 3272 } 3273 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3274 vfs_unbusy(mp, td); 3275 return (0); 3276 } 3277 asyncflag = mp->mnt_flag & MNT_ASYNC; 3278 mp->mnt_flag &= ~MNT_ASYNC; 3279 vfs_msync(mp, MNT_NOWAIT); 3280 VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3281 if (asyncflag) 3282 mp->mnt_flag |= MNT_ASYNC; 3283 vn_finished_write(mp); 3284 vfs_unbusy(mp, td); 3285 return (0); 3286 } 3287 3288 /* 3289 * The syncer vnode is no referenced. 3290 */ 3291 static int 3292 sync_inactive(ap) 3293 struct vop_inactive_args /* { 3294 struct vnode *a_vp; 3295 struct thread *a_td; 3296 } */ *ap; 3297 { 3298 3299 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 3300 vgone(ap->a_vp); 3301 return (0); 3302 } 3303 3304 /* 3305 * The syncer vnode is no longer needed and is being decommissioned. 3306 * 3307 * Modifications to the worklist must be protected at splbio(). 3308 */ 3309 static int 3310 sync_reclaim(ap) 3311 struct vop_reclaim_args /* { 3312 struct vnode *a_vp; 3313 } */ *ap; 3314 { 3315 struct vnode *vp = ap->a_vp; 3316 int s; 3317 3318 s = splbio(); 3319 vp->v_mount->mnt_syncer = NULL; 3320 VI_LOCK(vp); 3321 if (vp->v_iflag & VI_ONWORKLST) { 3322 LIST_REMOVE(vp, v_synclist); 3323 vp->v_iflag &= ~VI_ONWORKLST; 3324 } 3325 VI_UNLOCK(vp); 3326 splx(s); 3327 3328 return (0); 3329 } 3330 3331 /* 3332 * Print out a syncer vnode. 3333 */ 3334 static int 3335 sync_print(ap) 3336 struct vop_print_args /* { 3337 struct vnode *a_vp; 3338 } */ *ap; 3339 { 3340 struct vnode *vp = ap->a_vp; 3341 3342 printf("syncer vnode"); 3343 if (vp->v_vnlock != NULL) 3344 lockmgr_printinfo(vp->v_vnlock); 3345 printf("\n"); 3346 return (0); 3347 } 3348 3349 /* 3350 * extract the dev_t from a VCHR 3351 */ 3352 dev_t 3353 vn_todev(vp) 3354 struct vnode *vp; 3355 { 3356 if (vp->v_type != VCHR) 3357 return (NODEV); 3358 return (vp->v_rdev); 3359 } 3360 3361 /* 3362 * Check if vnode represents a disk device 3363 */ 3364 int 3365 vn_isdisk(vp, errp) 3366 struct vnode *vp; 3367 int *errp; 3368 { 3369 struct cdevsw *cdevsw; 3370 3371 if (vp->v_type != VCHR) { 3372 if (errp != NULL) 3373 *errp = ENOTBLK; 3374 return (0); 3375 } 3376 if (vp->v_rdev == NULL) { 3377 if (errp != NULL) 3378 *errp = ENXIO; 3379 return (0); 3380 } 3381 cdevsw = devsw(vp->v_rdev); 3382 if (cdevsw == NULL) { 3383 if (errp != NULL) 3384 *errp = ENXIO; 3385 return (0); 3386 } 3387 if (!(cdevsw->d_flags & D_DISK)) { 3388 if (errp != NULL) 3389 *errp = ENOTBLK; 3390 return (0); 3391 } 3392 if (errp != NULL) 3393 *errp = 0; 3394 return (1); 3395 } 3396 3397 /* 3398 * Free data allocated by namei(); see namei(9) for details. 3399 */ 3400 void 3401 NDFREE(ndp, flags) 3402 struct nameidata *ndp; 3403 const uint flags; 3404 { 3405 if (!(flags & NDF_NO_FREE_PNBUF) && 3406 (ndp->ni_cnd.cn_flags & HASBUF)) { 3407 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3408 ndp->ni_cnd.cn_flags &= ~HASBUF; 3409 } 3410 if (!(flags & NDF_NO_DVP_UNLOCK) && 3411 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3412 ndp->ni_dvp != ndp->ni_vp) 3413 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3414 if (!(flags & NDF_NO_DVP_RELE) && 3415 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3416 vrele(ndp->ni_dvp); 3417 ndp->ni_dvp = NULL; 3418 } 3419 if (!(flags & NDF_NO_VP_UNLOCK) && 3420 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3421 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3422 if (!(flags & NDF_NO_VP_RELE) && 3423 ndp->ni_vp) { 3424 vrele(ndp->ni_vp); 3425 ndp->ni_vp = NULL; 3426 } 3427 if (!(flags & NDF_NO_STARTDIR_RELE) && 3428 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3429 vrele(ndp->ni_startdir); 3430 ndp->ni_startdir = NULL; 3431 } 3432 } 3433 3434 /* 3435 * Common filesystem object access control check routine. Accepts a 3436 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3437 * and optional call-by-reference privused argument allowing vaccess() 3438 * to indicate to the caller whether privilege was used to satisfy the 3439 * request (obsoleted). Returns 0 on success, or an errno on failure. 3440 */ 3441 int 3442 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3443 enum vtype type; 3444 mode_t file_mode; 3445 uid_t file_uid; 3446 gid_t file_gid; 3447 mode_t acc_mode; 3448 struct ucred *cred; 3449 int *privused; 3450 { 3451 mode_t dac_granted; 3452 #ifdef CAPABILITIES 3453 mode_t cap_granted; 3454 #endif 3455 3456 /* 3457 * Look for a normal, non-privileged way to access the file/directory 3458 * as requested. If it exists, go with that. 3459 */ 3460 3461 if (privused != NULL) 3462 *privused = 0; 3463 3464 dac_granted = 0; 3465 3466 /* Check the owner. */ 3467 if (cred->cr_uid == file_uid) { 3468 dac_granted |= VADMIN; 3469 if (file_mode & S_IXUSR) 3470 dac_granted |= VEXEC; 3471 if (file_mode & S_IRUSR) 3472 dac_granted |= VREAD; 3473 if (file_mode & S_IWUSR) 3474 dac_granted |= (VWRITE | VAPPEND); 3475 3476 if ((acc_mode & dac_granted) == acc_mode) 3477 return (0); 3478 3479 goto privcheck; 3480 } 3481 3482 /* Otherwise, check the groups (first match) */ 3483 if (groupmember(file_gid, cred)) { 3484 if (file_mode & S_IXGRP) 3485 dac_granted |= VEXEC; 3486 if (file_mode & S_IRGRP) 3487 dac_granted |= VREAD; 3488 if (file_mode & S_IWGRP) 3489 dac_granted |= (VWRITE | VAPPEND); 3490 3491 if ((acc_mode & dac_granted) == acc_mode) 3492 return (0); 3493 3494 goto privcheck; 3495 } 3496 3497 /* Otherwise, check everyone else. */ 3498 if (file_mode & S_IXOTH) 3499 dac_granted |= VEXEC; 3500 if (file_mode & S_IROTH) 3501 dac_granted |= VREAD; 3502 if (file_mode & S_IWOTH) 3503 dac_granted |= (VWRITE | VAPPEND); 3504 if ((acc_mode & dac_granted) == acc_mode) 3505 return (0); 3506 3507 privcheck: 3508 if (!suser_cred(cred, PRISON_ROOT)) { 3509 /* XXX audit: privilege used */ 3510 if (privused != NULL) 3511 *privused = 1; 3512 return (0); 3513 } 3514 3515 #ifdef CAPABILITIES 3516 /* 3517 * Build a capability mask to determine if the set of capabilities 3518 * satisfies the requirements when combined with the granted mask 3519 * from above. 3520 * For each capability, if the capability is required, bitwise 3521 * or the request type onto the cap_granted mask. 3522 */ 3523 cap_granted = 0; 3524 3525 if (type == VDIR) { 3526 /* 3527 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3528 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3529 */ 3530 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3531 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3532 cap_granted |= VEXEC; 3533 } else { 3534 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3535 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3536 cap_granted |= VEXEC; 3537 } 3538 3539 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3540 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3541 cap_granted |= VREAD; 3542 3543 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3544 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3545 cap_granted |= (VWRITE | VAPPEND); 3546 3547 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3548 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3549 cap_granted |= VADMIN; 3550 3551 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3552 /* XXX audit: privilege used */ 3553 if (privused != NULL) 3554 *privused = 1; 3555 return (0); 3556 } 3557 #endif 3558 3559 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3560 } 3561