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