1 /* 2 * Copyright (c) 2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * Copyright (c) 1989, 1993 35 * The Regents of the University of California. All rights reserved. 36 * (c) UNIX System Laboratories, Inc. 37 * All or some portions of this file are derived from material licensed 38 * to the University of California by American Telephone and Telegraph 39 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 40 * the permission of UNIX System Laboratories, Inc. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 */ 66 67 /* 68 * External virtual filesystem routines 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/kernel.h> 74 #include <sys/malloc.h> 75 #include <sys/mount.h> 76 #include <sys/proc.h> 77 #include <sys/vnode.h> 78 #include <sys/buf.h> 79 #include <sys/eventhandler.h> 80 #include <sys/kthread.h> 81 #include <sys/sysctl.h> 82 83 #include <machine/limits.h> 84 85 #include <sys/buf2.h> 86 #include <sys/thread2.h> 87 #include <sys/sysref2.h> 88 89 #include <vm/vm.h> 90 #include <vm/vm_object.h> 91 92 struct mountscan_info { 93 TAILQ_ENTRY(mountscan_info) msi_entry; 94 int msi_how; 95 struct mount *msi_node; 96 }; 97 98 struct vmntvnodescan_info { 99 TAILQ_ENTRY(vmntvnodescan_info) entry; 100 struct vnode *vp; 101 }; 102 103 struct vnlru_info { 104 int pass; 105 }; 106 107 static int vnlru_nowhere = 0; 108 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RD, 109 &vnlru_nowhere, 0, 110 "Number of times the vnlru process ran without success"); 111 112 113 static struct lwkt_token mntid_token; 114 static struct mount dummymount; 115 116 /* note: mountlist exported to pstat */ 117 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 118 static TAILQ_HEAD(,mountscan_info) mountscan_list; 119 static struct lwkt_token mountlist_token; 120 121 static TAILQ_HEAD(,bio_ops) bio_ops_list = TAILQ_HEAD_INITIALIZER(bio_ops_list); 122 123 /* 124 * Called from vfsinit() 125 */ 126 void 127 vfs_mount_init(void) 128 { 129 lwkt_token_init(&mountlist_token, "mntlist"); 130 lwkt_token_init(&mntid_token, "mntid"); 131 TAILQ_INIT(&mountscan_list); 132 mount_init(&dummymount); 133 dummymount.mnt_flag |= MNT_RDONLY; 134 dummymount.mnt_kern_flag |= MNTK_ALL_MPSAFE; 135 } 136 137 /* 138 * Support function called to remove a vnode from the mountlist and 139 * deal with side effects for scans in progress. 140 * 141 * Target mnt_token is held on call. 142 */ 143 static void 144 vremovevnodemnt(struct vnode *vp) 145 { 146 struct vmntvnodescan_info *info; 147 struct mount *mp = vp->v_mount; 148 149 TAILQ_FOREACH(info, &mp->mnt_vnodescan_list, entry) { 150 if (info->vp == vp) 151 info->vp = TAILQ_NEXT(vp, v_nmntvnodes); 152 } 153 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 154 } 155 156 /* 157 * Allocate a new vnode and associate it with a tag, mount point, and 158 * operations vector. 159 * 160 * A VX locked and refd vnode is returned. The caller should setup the 161 * remaining fields and vx_put() or, if he wishes to leave a vref, 162 * vx_unlock() the vnode. 163 */ 164 int 165 getnewvnode(enum vtagtype tag, struct mount *mp, 166 struct vnode **vpp, int lktimeout, int lkflags) 167 { 168 struct vnode *vp; 169 170 KKASSERT(mp != NULL); 171 172 vp = allocvnode(lktimeout, lkflags); 173 vp->v_tag = tag; 174 vp->v_data = NULL; 175 176 /* 177 * By default the vnode is assigned the mount point's normal 178 * operations vector. 179 */ 180 vp->v_ops = &mp->mnt_vn_use_ops; 181 182 /* 183 * Placing the vnode on the mount point's queue makes it visible. 184 * VNON prevents it from being messed with, however. 185 */ 186 insmntque(vp, mp); 187 188 /* 189 * A VX locked & refd vnode is returned. 190 */ 191 *vpp = vp; 192 return (0); 193 } 194 195 /* 196 * This function creates vnodes with special operations vectors. The 197 * mount point is optional. 198 * 199 * This routine is being phased out but is still used by vfs_conf to 200 * create vnodes for devices prior to the root mount (with mp == NULL). 201 */ 202 int 203 getspecialvnode(enum vtagtype tag, struct mount *mp, 204 struct vop_ops **ops, 205 struct vnode **vpp, int lktimeout, int lkflags) 206 { 207 struct vnode *vp; 208 209 vp = allocvnode(lktimeout, lkflags); 210 vp->v_tag = tag; 211 vp->v_data = NULL; 212 vp->v_ops = ops; 213 214 if (mp == NULL) 215 mp = &dummymount; 216 217 /* 218 * Placing the vnode on the mount point's queue makes it visible. 219 * VNON prevents it from being messed with, however. 220 */ 221 insmntque(vp, mp); 222 223 /* 224 * A VX locked & refd vnode is returned. 225 */ 226 *vpp = vp; 227 return (0); 228 } 229 230 /* 231 * Interlock against an unmount, return 0 on success, non-zero on failure. 232 * 233 * The passed flag may be 0 or LK_NOWAIT and is only used if an unmount 234 * is in-progress. 235 * 236 * If no unmount is in-progress LK_NOWAIT is ignored. No other flag bits 237 * are used. A shared locked will be obtained and the filesystem will not 238 * be unmountable until the lock is released. 239 */ 240 int 241 vfs_busy(struct mount *mp, int flags) 242 { 243 int lkflags; 244 245 atomic_add_int(&mp->mnt_refs, 1); 246 lwkt_gettoken(&mp->mnt_token); 247 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 248 if (flags & LK_NOWAIT) { 249 lwkt_reltoken(&mp->mnt_token); 250 atomic_add_int(&mp->mnt_refs, -1); 251 return (ENOENT); 252 } 253 /* XXX not MP safe */ 254 mp->mnt_kern_flag |= MNTK_MWAIT; 255 /* 256 * Since all busy locks are shared except the exclusive 257 * lock granted when unmounting, the only place that a 258 * wakeup needs to be done is at the release of the 259 * exclusive lock at the end of dounmount. 260 */ 261 tsleep((caddr_t)mp, 0, "vfs_busy", 0); 262 lwkt_reltoken(&mp->mnt_token); 263 atomic_add_int(&mp->mnt_refs, -1); 264 return (ENOENT); 265 } 266 lkflags = LK_SHARED; 267 if (lockmgr(&mp->mnt_lock, lkflags)) 268 panic("vfs_busy: unexpected lock failure"); 269 lwkt_reltoken(&mp->mnt_token); 270 return (0); 271 } 272 273 /* 274 * Free a busy filesystem. 275 * 276 * Decrement refs before releasing the lock so e.g. a pending umount 277 * doesn't give us an unexpected busy error. 278 */ 279 void 280 vfs_unbusy(struct mount *mp) 281 { 282 atomic_add_int(&mp->mnt_refs, -1); 283 lockmgr(&mp->mnt_lock, LK_RELEASE); 284 } 285 286 /* 287 * Lookup a filesystem type, and if found allocate and initialize 288 * a mount structure for it. 289 * 290 * Devname is usually updated by mount(8) after booting. 291 */ 292 int 293 vfs_rootmountalloc(char *fstypename, char *devname, struct mount **mpp) 294 { 295 struct vfsconf *vfsp; 296 struct mount *mp; 297 298 if (fstypename == NULL) 299 return (ENODEV); 300 301 vfsp = vfsconf_find_by_name(fstypename); 302 if (vfsp == NULL) 303 return (ENODEV); 304 mp = kmalloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 305 mount_init(mp); 306 lockinit(&mp->mnt_lock, "vfslock", VLKTIMEOUT, 0); 307 308 vfs_busy(mp, 0); 309 mp->mnt_vfc = vfsp; 310 mp->mnt_op = vfsp->vfc_vfsops; 311 vfsp->vfc_refcount++; 312 mp->mnt_stat.f_type = vfsp->vfc_typenum; 313 mp->mnt_flag |= MNT_RDONLY; 314 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 315 strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 316 copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0); 317 *mpp = mp; 318 return (0); 319 } 320 321 /* 322 * Basic mount structure initialization 323 */ 324 void 325 mount_init(struct mount *mp) 326 { 327 lockinit(&mp->mnt_lock, "vfslock", hz*5, 0); 328 lwkt_token_init(&mp->mnt_token, "permnt"); 329 330 TAILQ_INIT(&mp->mnt_vnodescan_list); 331 TAILQ_INIT(&mp->mnt_nvnodelist); 332 TAILQ_INIT(&mp->mnt_reservedvnlist); 333 TAILQ_INIT(&mp->mnt_jlist); 334 mp->mnt_nvnodelistsize = 0; 335 mp->mnt_flag = 0; 336 mp->mnt_iosize_max = MAXPHYS; 337 vn_syncer_thr_create(mp); 338 } 339 340 /* 341 * Lookup a mount point by filesystem identifier. 342 */ 343 struct mount * 344 vfs_getvfs(fsid_t *fsid) 345 { 346 struct mount *mp; 347 348 lwkt_gettoken(&mountlist_token); 349 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 350 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 351 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 352 break; 353 } 354 } 355 lwkt_reltoken(&mountlist_token); 356 return (mp); 357 } 358 359 /* 360 * Get a new unique fsid. Try to make its val[0] unique, since this value 361 * will be used to create fake device numbers for stat(). Also try (but 362 * not so hard) make its val[0] unique mod 2^16, since some emulators only 363 * support 16-bit device numbers. We end up with unique val[0]'s for the 364 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 365 * 366 * Keep in mind that several mounts may be running in parallel. Starting 367 * the search one past where the previous search terminated is both a 368 * micro-optimization and a defense against returning the same fsid to 369 * different mounts. 370 */ 371 void 372 vfs_getnewfsid(struct mount *mp) 373 { 374 static u_int16_t mntid_base; 375 fsid_t tfsid; 376 int mtype; 377 378 lwkt_gettoken(&mntid_token); 379 mtype = mp->mnt_vfc->vfc_typenum; 380 tfsid.val[1] = mtype; 381 mtype = (mtype & 0xFF) << 24; 382 for (;;) { 383 tfsid.val[0] = makeudev(255, 384 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 385 mntid_base++; 386 if (vfs_getvfs(&tfsid) == NULL) 387 break; 388 } 389 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 390 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 391 lwkt_reltoken(&mntid_token); 392 } 393 394 /* 395 * Set the FSID for a new mount point to the template. Adjust 396 * the FSID to avoid collisions. 397 */ 398 int 399 vfs_setfsid(struct mount *mp, fsid_t *template) 400 { 401 int didmunge = 0; 402 403 bzero(&mp->mnt_stat.f_fsid, sizeof(mp->mnt_stat.f_fsid)); 404 for (;;) { 405 if (vfs_getvfs(template) == NULL) 406 break; 407 didmunge = 1; 408 ++template->val[1]; 409 } 410 mp->mnt_stat.f_fsid = *template; 411 return(didmunge); 412 } 413 414 /* 415 * This routine is called when we have too many vnodes. It attempts 416 * to free <count> vnodes and will potentially free vnodes that still 417 * have VM backing store (VM backing store is typically the cause 418 * of a vnode blowout so we want to do this). Therefore, this operation 419 * is not considered cheap. 420 * 421 * A number of conditions may prevent a vnode from being reclaimed. 422 * the buffer cache may have references on the vnode, a directory 423 * vnode may still have references due to the namei cache representing 424 * underlying files, or the vnode may be in active use. It is not 425 * desireable to reuse such vnodes. These conditions may cause the 426 * number of vnodes to reach some minimum value regardless of what 427 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 428 */ 429 430 /* 431 * This is a quick non-blocking check to determine if the vnode is a good 432 * candidate for being (eventually) vgone()'d. Returns 0 if the vnode is 433 * not a good candidate, 1 if it is. 434 */ 435 static __inline int 436 vmightfree(struct vnode *vp, int page_count, int pass) 437 { 438 if (vp->v_flag & VRECLAIMED) 439 return (0); 440 if (VREFCNT(vp) > 0) 441 return (0); 442 if (vp->v_object && vp->v_object->resident_page_count >= page_count) 443 return (0); 444 445 /* 446 * XXX horrible hack. Up to four passes will be taken. Each pass 447 * makes a larger set of vnodes eligible. For now what this really 448 * means is that we try to recycle files opened only once before 449 * recycling files opened multiple times. 450 */ 451 switch(vp->v_flag & (VAGE0 | VAGE1)) { 452 case 0: 453 if (pass < 3) 454 return(0); 455 break; 456 case VAGE0: 457 if (pass < 2) 458 return(0); 459 break; 460 case VAGE1: 461 if (pass < 1) 462 return(0); 463 break; 464 case VAGE0 | VAGE1: 465 break; 466 } 467 return (1); 468 } 469 470 /* 471 * The vnode was found to be possibly vgone()able and the caller has locked it 472 * (thus the usecount should be 1 now). Determine if the vnode is actually 473 * vgone()able, doing some cleanups in the process. Returns 1 if the vnode 474 * can be vgone()'d, 0 otherwise. 475 * 476 * Note that v_auxrefs may be non-zero because (A) this vnode is not a leaf 477 * in the namecache topology and (B) this vnode has buffer cache bufs. 478 * We cannot remove vnodes with non-leaf namecache associations. We do a 479 * tentitive leaf check prior to attempting to flush out any buffers but the 480 * 'real' test when all is said in done is that v_auxrefs must become 0 for 481 * the vnode to be freeable. 482 * 483 * We could theoretically just unconditionally flush when v_auxrefs != 0, 484 * but flushing data associated with non-leaf nodes (which are always 485 * directories), just throws it away for no benefit. It is the buffer 486 * cache's responsibility to choose buffers to recycle from the cached 487 * data point of view. 488 */ 489 static int 490 visleaf(struct vnode *vp) 491 { 492 struct namecache *ncp; 493 494 spin_lock(&vp->v_spin); 495 TAILQ_FOREACH(ncp, &vp->v_namecache, nc_vnode) { 496 if (!TAILQ_EMPTY(&ncp->nc_list)) { 497 spin_unlock(&vp->v_spin); 498 return(0); 499 } 500 } 501 spin_unlock(&vp->v_spin); 502 return(1); 503 } 504 505 /* 506 * Try to clean up the vnode to the point where it can be vgone()'d, returning 507 * 0 if it cannot be vgone()'d (or already has been), 1 if it can. Unlike 508 * vmightfree() this routine may flush the vnode and block. 509 */ 510 static int 511 vtrytomakegoneable(struct vnode *vp, int page_count) 512 { 513 if (vp->v_flag & VRECLAIMED) 514 return (0); 515 if (VREFCNT(vp) > 1) 516 return (0); 517 if (vp->v_object && vp->v_object->resident_page_count >= page_count) 518 return (0); 519 if (vp->v_auxrefs && visleaf(vp)) { 520 vinvalbuf(vp, V_SAVE, 0, 0); 521 #if 0 /* DEBUG */ 522 kprintf((vp->v_auxrefs ? "vrecycle: vp %p failed: %s\n" : 523 "vrecycle: vp %p succeeded: %s\n"), vp, 524 (TAILQ_FIRST(&vp->v_namecache) ? 525 TAILQ_FIRST(&vp->v_namecache)->nc_name : "?")); 526 #endif 527 } 528 529 /* 530 * This sequence may seem a little strange, but we need to optimize 531 * the critical path a bit. We can't recycle vnodes with other 532 * references and because we are trying to recycle an otherwise 533 * perfectly fine vnode we have to invalidate the namecache in a 534 * way that avoids possible deadlocks (since the vnode lock is being 535 * held here). Finally, we have to check for other references one 536 * last time in case something snuck in during the inval. 537 */ 538 if (VREFCNT(vp) > 1 || vp->v_auxrefs != 0) 539 return (0); 540 if (cache_inval_vp_nonblock(vp)) 541 return (0); 542 return (VREFCNT(vp) <= 1 && vp->v_auxrefs == 0); 543 } 544 545 /* 546 * Reclaim up to 1/10 of the vnodes associated with a mount point. Try 547 * to avoid vnodes which have lots of resident pages (we are trying to free 548 * vnodes, not memory). 549 * 550 * This routine is a callback from the mountlist scan. The mount point 551 * in question will be busied. 552 * 553 * NOTE: The 1/10 reclamation also ensures that the inactive data set 554 * (the vnodes being recycled by the one-time use) does not degenerate 555 * into too-small a set. This is important because once a vnode is 556 * marked as not being one-time-use (VAGE0/VAGE1 both 0) that vnode 557 * will not be destroyed EXCEPT by this mechanism. VM pages can still 558 * be cleaned/freed by the pageout daemon. 559 */ 560 static int 561 vlrureclaim(struct mount *mp, void *data) 562 { 563 struct vnlru_info *info = data; 564 struct vnode *vp; 565 int done; 566 int trigger; 567 int usevnodes; 568 int count; 569 int trigger_mult = vnlru_nowhere; 570 571 /* 572 * Calculate the trigger point for the resident pages check. The 573 * minimum trigger value is approximately the number of pages in 574 * the system divded by the number of vnodes. However, due to 575 * various other system memory overheads unrelated to data caching 576 * it is a good idea to double the trigger (at least). 577 * 578 * trigger_mult starts at 0. If the recycler is having problems 579 * finding enough freeable vnodes it will increase trigger_mult. 580 * This should not happen in normal operation, even on machines with 581 * low amounts of memory, but extraordinary memory use by the system 582 * verses the amount of cached data can trigger it. 583 * 584 * (long) -> deal with 64 bit machines, intermediate overflow 585 */ 586 usevnodes = desiredvnodes; 587 if (usevnodes <= 0) 588 usevnodes = 1; 589 trigger = (long)vmstats.v_page_count * (trigger_mult + 2) / usevnodes; 590 591 done = 0; 592 lwkt_gettoken(&mp->mnt_token); 593 count = mp->mnt_nvnodelistsize / 10 + 1; 594 595 while (count && mp->mnt_syncer) { 596 /* 597 * Next vnode. Use the special syncer vnode to placemark 598 * the LRU. This way the LRU code does not interfere with 599 * vmntvnodescan(). 600 */ 601 vp = TAILQ_NEXT(mp->mnt_syncer, v_nmntvnodes); 602 TAILQ_REMOVE(&mp->mnt_nvnodelist, mp->mnt_syncer, v_nmntvnodes); 603 if (vp) { 604 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, 605 mp->mnt_syncer, v_nmntvnodes); 606 } else { 607 TAILQ_INSERT_HEAD(&mp->mnt_nvnodelist, mp->mnt_syncer, 608 v_nmntvnodes); 609 vp = TAILQ_NEXT(mp->mnt_syncer, v_nmntvnodes); 610 if (vp == NULL) 611 break; 612 } 613 614 /* 615 * __VNODESCAN__ 616 * 617 * The VP will stick around while we hold mnt_token, 618 * at least until we block, so we can safely do an initial 619 * check, and then must check again after we lock the vnode. 620 */ 621 if (vp->v_type == VNON || /* syncer or indeterminant */ 622 !vmightfree(vp, trigger, info->pass) /* critical path opt */ 623 ) { 624 --count; 625 continue; 626 } 627 628 /* 629 * VX get the candidate vnode. If the VX get fails the 630 * vnode might still be on the mountlist. Our loop depends 631 * on us at least cycling the vnode to the end of the 632 * mountlist. 633 */ 634 if (vx_get_nonblock(vp) != 0) { 635 --count; 636 continue; 637 } 638 639 /* 640 * Since we blocked locking the vp, make sure it is still 641 * a candidate for reclamation. That is, it has not already 642 * been reclaimed and only has our VX reference associated 643 * with it. 644 */ 645 if (vp->v_type == VNON || /* syncer or indeterminant */ 646 (vp->v_flag & VRECLAIMED) || 647 vp->v_mount != mp || 648 !vtrytomakegoneable(vp, trigger) /* critical path opt */ 649 ) { 650 --count; 651 vx_put(vp); 652 continue; 653 } 654 655 /* 656 * All right, we are good, move the vp to the end of the 657 * mountlist and clean it out. The vget will have returned 658 * an error if the vnode was destroyed (VRECLAIMED set), so we 659 * do not have to check again. The vput() will move the 660 * vnode to the free list if the vgone() was successful. 661 */ 662 KKASSERT(vp->v_mount == mp); 663 vgone_vxlocked(vp); 664 vx_put(vp); 665 ++done; 666 --count; 667 } 668 lwkt_reltoken(&mp->mnt_token); 669 return (done); 670 } 671 672 /* 673 * Attempt to recycle vnodes in a context that is always safe to block. 674 * Calling vlrurecycle() from the bowels of file system code has some 675 * interesting deadlock problems. 676 */ 677 static struct thread *vnlruthread; 678 679 static void 680 vnlru_proc(void) 681 { 682 struct thread *td = curthread; 683 struct vnlru_info info; 684 int done; 685 686 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc, td, 687 SHUTDOWN_PRI_FIRST); 688 689 for (;;) { 690 kproc_suspend_loop(); 691 692 /* 693 * Do some opportunistic roving. 694 */ 695 if (numvnodes > 100000) 696 vnode_free_rover_scan(50); 697 else if (numvnodes > 10000) 698 vnode_free_rover_scan(20); 699 else 700 vnode_free_rover_scan(5); 701 702 /* 703 * Try to free some vnodes if we have too many 704 * 705 * (long) -> deal with 64 bit machines, intermediate overflow 706 */ 707 if (numvnodes > desiredvnodes && 708 cachedvnodes > desiredvnodes * 2 / 10) { 709 int count = numvnodes - desiredvnodes; 710 711 if (count > cachedvnodes / 100) 712 count = cachedvnodes / 100; 713 if (count < 5) 714 count = 5; 715 freesomevnodes(count); 716 } 717 718 /* 719 * Do non-critical-path (more robust) cache cleaning, 720 * even if vnode counts are nominal, to try to avoid 721 * having to do it in the critical path. 722 */ 723 cache_hysteresis(0); 724 725 /* 726 * Nothing to do if most of our vnodes are already on 727 * the free list. 728 */ 729 if (numvnodes - cachedvnodes <= (long)desiredvnodes * 9 / 10) { 730 tsleep(vnlruthread, 0, "vlruwt", hz); 731 continue; 732 } 733 734 /* 735 * The pass iterates through the four combinations of 736 * VAGE0/VAGE1. We want to get rid of aged small files 737 * first. 738 */ 739 info.pass = 0; 740 done = 0; 741 while (done == 0 && info.pass < 4) { 742 done = mountlist_scan(vlrureclaim, &info, 743 MNTSCAN_FORWARD); 744 ++info.pass; 745 } 746 747 /* 748 * The vlrureclaim() call only processes 1/10 of the vnodes 749 * on each mount. If we couldn't find any repeat the loop 750 * at least enough times to cover all available vnodes before 751 * we start sleeping. Complain if the failure extends past 752 * 30 second, every 30 seconds. 753 */ 754 if (done == 0) { 755 ++vnlru_nowhere; 756 if (vnlru_nowhere % 10 == 0) 757 tsleep(vnlruthread, 0, "vlrup", hz * 3); 758 if (vnlru_nowhere % 100 == 0) 759 kprintf("vnlru_proc: vnode recycler stopped working!\n"); 760 if (vnlru_nowhere == 1000) 761 vnlru_nowhere = 900; 762 } else { 763 vnlru_nowhere = 0; 764 } 765 } 766 } 767 768 /* 769 * MOUNTLIST FUNCTIONS 770 */ 771 772 /* 773 * mountlist_insert (MP SAFE) 774 * 775 * Add a new mount point to the mount list. 776 */ 777 void 778 mountlist_insert(struct mount *mp, int how) 779 { 780 lwkt_gettoken(&mountlist_token); 781 if (how == MNTINS_FIRST) 782 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 783 else 784 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 785 lwkt_reltoken(&mountlist_token); 786 } 787 788 /* 789 * mountlist_interlock (MP SAFE) 790 * 791 * Execute the specified interlock function with the mountlist token 792 * held. The function will be called in a serialized fashion verses 793 * other functions called through this mechanism. 794 */ 795 int 796 mountlist_interlock(int (*callback)(struct mount *), struct mount *mp) 797 { 798 int error; 799 800 lwkt_gettoken(&mountlist_token); 801 error = callback(mp); 802 lwkt_reltoken(&mountlist_token); 803 return (error); 804 } 805 806 /* 807 * mountlist_boot_getfirst (DURING BOOT ONLY) 808 * 809 * This function returns the first mount on the mountlist, which is 810 * expected to be the root mount. Since no interlocks are obtained 811 * this function is only safe to use during booting. 812 */ 813 814 struct mount * 815 mountlist_boot_getfirst(void) 816 { 817 return(TAILQ_FIRST(&mountlist)); 818 } 819 820 /* 821 * mountlist_remove (MP SAFE) 822 * 823 * Remove a node from the mountlist. If this node is the next scan node 824 * for any active mountlist scans, the active mountlist scan will be 825 * adjusted to skip the node, thus allowing removals during mountlist 826 * scans. 827 */ 828 void 829 mountlist_remove(struct mount *mp) 830 { 831 struct mountscan_info *msi; 832 833 lwkt_gettoken(&mountlist_token); 834 TAILQ_FOREACH(msi, &mountscan_list, msi_entry) { 835 if (msi->msi_node == mp) { 836 if (msi->msi_how & MNTSCAN_FORWARD) 837 msi->msi_node = TAILQ_NEXT(mp, mnt_list); 838 else 839 msi->msi_node = TAILQ_PREV(mp, mntlist, mnt_list); 840 } 841 } 842 TAILQ_REMOVE(&mountlist, mp, mnt_list); 843 lwkt_reltoken(&mountlist_token); 844 } 845 846 /* 847 * mountlist_exists (MP SAFE) 848 * 849 * Checks if a node exists in the mountlist. 850 * This function is mainly used by VFS quota code to check if a 851 * cached nullfs struct mount pointer is still valid at use time 852 * 853 * FIXME: there is no warranty the mp passed to that function 854 * will be the same one used by VFS_ACCOUNT() later 855 */ 856 int 857 mountlist_exists(struct mount *mp) 858 { 859 int node_exists = 0; 860 struct mount* lmp; 861 862 lwkt_gettoken(&mountlist_token); 863 TAILQ_FOREACH(lmp, &mountlist, mnt_list) { 864 if (lmp == mp) { 865 node_exists = 1; 866 break; 867 } 868 } 869 lwkt_reltoken(&mountlist_token); 870 return(node_exists); 871 } 872 873 /* 874 * mountlist_scan (MP SAFE) 875 * 876 * Safely scan the mount points on the mount list. Unless otherwise 877 * specified each mount point will be busied prior to the callback and 878 * unbusied afterwords. The callback may safely remove any mount point 879 * without interfering with the scan. If the current callback 880 * mount is removed the scanner will not attempt to unbusy it. 881 * 882 * If a mount node cannot be busied it is silently skipped. 883 * 884 * The callback return value is aggregated and a total is returned. A return 885 * value of < 0 is not aggregated and will terminate the scan. 886 * 887 * MNTSCAN_FORWARD - the mountlist is scanned in the forward direction 888 * MNTSCAN_REVERSE - the mountlist is scanned in reverse 889 * MNTSCAN_NOBUSY - the scanner will make the callback without busying 890 * the mount node. 891 */ 892 int 893 mountlist_scan(int (*callback)(struct mount *, void *), void *data, int how) 894 { 895 struct mountscan_info info; 896 struct mount *mp; 897 int count; 898 int res; 899 900 lwkt_gettoken(&mountlist_token); 901 902 info.msi_how = how; 903 info.msi_node = NULL; /* paranoia */ 904 TAILQ_INSERT_TAIL(&mountscan_list, &info, msi_entry); 905 906 res = 0; 907 908 if (how & MNTSCAN_FORWARD) { 909 info.msi_node = TAILQ_FIRST(&mountlist); 910 while ((mp = info.msi_node) != NULL) { 911 if (how & MNTSCAN_NOBUSY) { 912 count = callback(mp, data); 913 } else if (vfs_busy(mp, LK_NOWAIT) == 0) { 914 count = callback(mp, data); 915 if (mp == info.msi_node) 916 vfs_unbusy(mp); 917 } else { 918 count = 0; 919 } 920 if (count < 0) 921 break; 922 res += count; 923 if (mp == info.msi_node) 924 info.msi_node = TAILQ_NEXT(mp, mnt_list); 925 } 926 } else if (how & MNTSCAN_REVERSE) { 927 info.msi_node = TAILQ_LAST(&mountlist, mntlist); 928 while ((mp = info.msi_node) != NULL) { 929 if (how & MNTSCAN_NOBUSY) { 930 count = callback(mp, data); 931 } else if (vfs_busy(mp, LK_NOWAIT) == 0) { 932 count = callback(mp, data); 933 if (mp == info.msi_node) 934 vfs_unbusy(mp); 935 } else { 936 count = 0; 937 } 938 if (count < 0) 939 break; 940 res += count; 941 if (mp == info.msi_node) 942 info.msi_node = TAILQ_PREV(mp, mntlist, mnt_list); 943 } 944 } 945 TAILQ_REMOVE(&mountscan_list, &info, msi_entry); 946 lwkt_reltoken(&mountlist_token); 947 return(res); 948 } 949 950 /* 951 * MOUNT RELATED VNODE FUNCTIONS 952 */ 953 954 static struct kproc_desc vnlru_kp = { 955 "vnlru", 956 vnlru_proc, 957 &vnlruthread 958 }; 959 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 960 961 /* 962 * Move a vnode from one mount queue to another. 963 * 964 * MPSAFE 965 */ 966 void 967 insmntque(struct vnode *vp, struct mount *mp) 968 { 969 struct mount *omp; 970 971 /* 972 * Delete from old mount point vnode list, if on one. 973 */ 974 if ((omp = vp->v_mount) != NULL) { 975 lwkt_gettoken(&omp->mnt_token); 976 KKASSERT(omp == vp->v_mount); 977 KASSERT(omp->mnt_nvnodelistsize > 0, 978 ("bad mount point vnode list size")); 979 vremovevnodemnt(vp); 980 omp->mnt_nvnodelistsize--; 981 lwkt_reltoken(&omp->mnt_token); 982 } 983 984 /* 985 * Insert into list of vnodes for the new mount point, if available. 986 * The 'end' of the LRU list is the vnode prior to mp->mnt_syncer. 987 */ 988 if (mp == NULL) { 989 vp->v_mount = NULL; 990 return; 991 } 992 lwkt_gettoken(&mp->mnt_token); 993 vp->v_mount = mp; 994 if (mp->mnt_syncer) { 995 TAILQ_INSERT_BEFORE(mp->mnt_syncer, vp, v_nmntvnodes); 996 } else { 997 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 998 } 999 mp->mnt_nvnodelistsize++; 1000 lwkt_reltoken(&mp->mnt_token); 1001 } 1002 1003 1004 /* 1005 * Scan the vnodes under a mount point and issue appropriate callbacks. 1006 * 1007 * The fastfunc() callback is called with just the mountlist token held 1008 * (no vnode lock). It may not block and the vnode may be undergoing 1009 * modifications while the caller is processing it. The vnode will 1010 * not be entirely destroyed, however, due to the fact that the mountlist 1011 * token is held. A return value < 0 skips to the next vnode without calling 1012 * the slowfunc(), a return value > 0 terminates the loop. 1013 * 1014 * The slowfunc() callback is called after the vnode has been successfully 1015 * locked based on passed flags. The vnode is skipped if it gets rearranged 1016 * or destroyed while blocking on the lock. A non-zero return value from 1017 * the slow function terminates the loop. The slow function is allowed to 1018 * arbitrarily block. The scanning code guarentees consistency of operation 1019 * even if the slow function deletes or moves the node, or blocks and some 1020 * other thread deletes or moves the node. 1021 * 1022 * NOTE: We hold vmobj_token to prevent a VM object from being destroyed 1023 * out from under the fastfunc()'s vnode test. It will not prevent 1024 * v_object from getting NULL'd out but it will ensure that the 1025 * pointer (if we race) will remain stable. Only needed when 1026 * fastfunc is non-NULL. 1027 */ 1028 int 1029 vmntvnodescan( 1030 struct mount *mp, 1031 int flags, 1032 int (*fastfunc)(struct mount *mp, struct vnode *vp, void *data), 1033 int (*slowfunc)(struct mount *mp, struct vnode *vp, void *data), 1034 void *data 1035 ) { 1036 struct vmntvnodescan_info info; 1037 struct vnode *vp; 1038 int r = 0; 1039 int maxcount = mp->mnt_nvnodelistsize * 2; 1040 int stopcount = 0; 1041 int count = 0; 1042 1043 lwkt_gettoken(&mp->mnt_token); 1044 if (fastfunc) 1045 lwkt_gettoken(&vmobj_token); 1046 1047 /* 1048 * If asked to do one pass stop after iterating available vnodes. 1049 * Under heavy loads new vnodes can be added while we are scanning, 1050 * so this isn't perfect. Create a slop factor of 2x. 1051 */ 1052 if (flags & VMSC_ONEPASS) 1053 stopcount = mp->mnt_nvnodelistsize; 1054 1055 info.vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1056 TAILQ_INSERT_TAIL(&mp->mnt_vnodescan_list, &info, entry); 1057 1058 while ((vp = info.vp) != NULL) { 1059 if (--maxcount == 0) { 1060 kprintf("Warning: excessive fssync iteration\n"); 1061 maxcount = mp->mnt_nvnodelistsize * 2; 1062 } 1063 1064 /* 1065 * Skip if visible but not ready, or special (e.g. 1066 * mp->mnt_syncer) 1067 */ 1068 if (vp->v_type == VNON) 1069 goto next; 1070 KKASSERT(vp->v_mount == mp); 1071 1072 /* 1073 * Quick test. A negative return continues the loop without 1074 * calling the slow test. 0 continues onto the slow test. 1075 * A positive number aborts the loop. 1076 */ 1077 if (fastfunc) { 1078 if ((r = fastfunc(mp, vp, data)) < 0) { 1079 r = 0; 1080 goto next; 1081 } 1082 if (r) 1083 break; 1084 } 1085 1086 /* 1087 * Get a vxlock on the vnode, retry if it has moved or isn't 1088 * in the mountlist where we expect it. 1089 */ 1090 if (slowfunc) { 1091 int error; 1092 1093 switch(flags & (VMSC_GETVP|VMSC_GETVX|VMSC_NOWAIT)) { 1094 case VMSC_GETVP: 1095 error = vget(vp, LK_EXCLUSIVE); 1096 break; 1097 case VMSC_GETVP|VMSC_NOWAIT: 1098 error = vget(vp, LK_EXCLUSIVE|LK_NOWAIT); 1099 break; 1100 case VMSC_GETVX: 1101 vx_get(vp); 1102 error = 0; 1103 break; 1104 default: 1105 error = 0; 1106 break; 1107 } 1108 if (error) 1109 goto next; 1110 /* 1111 * Do not call the slow function if the vnode is 1112 * invalid or if it was ripped out from under us 1113 * while we (potentially) blocked. 1114 */ 1115 if (info.vp == vp && vp->v_type != VNON) 1116 r = slowfunc(mp, vp, data); 1117 1118 /* 1119 * Cleanup 1120 */ 1121 switch(flags & (VMSC_GETVP|VMSC_GETVX|VMSC_NOWAIT)) { 1122 case VMSC_GETVP: 1123 case VMSC_GETVP|VMSC_NOWAIT: 1124 vput(vp); 1125 break; 1126 case VMSC_GETVX: 1127 vx_put(vp); 1128 break; 1129 default: 1130 break; 1131 } 1132 if (r != 0) 1133 break; 1134 } 1135 1136 next: 1137 /* 1138 * Yield after some processing. Depending on the number 1139 * of vnodes, we might wind up running for a long time. 1140 * Because threads are not preemptable, time critical 1141 * userland processes might starve. Give them a chance 1142 * now and then. 1143 */ 1144 if (++count == 10000) { 1145 /* 1146 * We really want to yield a bit, so we simply 1147 * sleep a tick 1148 */ 1149 tsleep(mp, 0, "vnodescn", 1); 1150 count = 0; 1151 } 1152 1153 /* 1154 * If doing one pass this decrements to zero. If it starts 1155 * at zero it is effectively unlimited for the purposes of 1156 * this loop. 1157 */ 1158 if (--stopcount == 0) 1159 break; 1160 1161 /* 1162 * Iterate. If the vnode was ripped out from under us 1163 * info.vp will already point to the next vnode, otherwise 1164 * we have to obtain the next valid vnode ourselves. 1165 */ 1166 if (info.vp == vp) 1167 info.vp = TAILQ_NEXT(vp, v_nmntvnodes); 1168 } 1169 1170 TAILQ_REMOVE(&mp->mnt_vnodescan_list, &info, entry); 1171 if (fastfunc) 1172 lwkt_reltoken(&vmobj_token); 1173 lwkt_reltoken(&mp->mnt_token); 1174 return(r); 1175 } 1176 1177 /* 1178 * Remove any vnodes in the vnode table belonging to mount point mp. 1179 * 1180 * If FORCECLOSE is not specified, there should not be any active ones, 1181 * return error if any are found (nb: this is a user error, not a 1182 * system error). If FORCECLOSE is specified, detach any active vnodes 1183 * that are found. 1184 * 1185 * If WRITECLOSE is set, only flush out regular file vnodes open for 1186 * writing. 1187 * 1188 * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped. 1189 * 1190 * `rootrefs' specifies the base reference count for the root vnode 1191 * of this filesystem. The root vnode is considered busy if its 1192 * v_refcnt exceeds this value. On a successful return, vflush() 1193 * will call vrele() on the root vnode exactly rootrefs times. 1194 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 1195 * be zero. 1196 */ 1197 #ifdef DIAGNOSTIC 1198 static int busyprt = 0; /* print out busy vnodes */ 1199 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 1200 #endif 1201 1202 static int vflush_scan(struct mount *mp, struct vnode *vp, void *data); 1203 1204 struct vflush_info { 1205 int flags; 1206 int busy; 1207 thread_t td; 1208 }; 1209 1210 int 1211 vflush(struct mount *mp, int rootrefs, int flags) 1212 { 1213 struct thread *td = curthread; /* XXX */ 1214 struct vnode *rootvp = NULL; 1215 int error; 1216 struct vflush_info vflush_info; 1217 1218 if (rootrefs > 0) { 1219 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 1220 ("vflush: bad args")); 1221 /* 1222 * Get the filesystem root vnode. We can vput() it 1223 * immediately, since with rootrefs > 0, it won't go away. 1224 */ 1225 if ((error = VFS_ROOT(mp, &rootvp)) != 0) { 1226 if ((flags & FORCECLOSE) == 0) 1227 return (error); 1228 rootrefs = 0; 1229 /* continue anyway */ 1230 } 1231 if (rootrefs) 1232 vput(rootvp); 1233 } 1234 1235 vflush_info.busy = 0; 1236 vflush_info.flags = flags; 1237 vflush_info.td = td; 1238 vmntvnodescan(mp, VMSC_GETVX, NULL, vflush_scan, &vflush_info); 1239 1240 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 1241 /* 1242 * If just the root vnode is busy, and if its refcount 1243 * is equal to `rootrefs', then go ahead and kill it. 1244 */ 1245 KASSERT(vflush_info.busy > 0, ("vflush: not busy")); 1246 KASSERT(VREFCNT(rootvp) >= rootrefs, ("vflush: rootrefs")); 1247 if (vflush_info.busy == 1 && VREFCNT(rootvp) == rootrefs) { 1248 vx_lock(rootvp); 1249 vgone_vxlocked(rootvp); 1250 vx_unlock(rootvp); 1251 vflush_info.busy = 0; 1252 } 1253 } 1254 if (vflush_info.busy) 1255 return (EBUSY); 1256 for (; rootrefs > 0; rootrefs--) 1257 vrele(rootvp); 1258 return (0); 1259 } 1260 1261 /* 1262 * The scan callback is made with an VX locked vnode. 1263 */ 1264 static int 1265 vflush_scan(struct mount *mp, struct vnode *vp, void *data) 1266 { 1267 struct vflush_info *info = data; 1268 struct vattr vattr; 1269 int flags = info->flags; 1270 1271 /* 1272 * Generally speaking try to deactivate on 0 refs (catch-all) 1273 */ 1274 atomic_set_int(&vp->v_refcnt, VREF_FINALIZE); 1275 1276 /* 1277 * Skip over a vnodes marked VSYSTEM. 1278 */ 1279 if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) { 1280 return(0); 1281 } 1282 1283 /* 1284 * Do not force-close VCHR or VBLK vnodes 1285 */ 1286 if (vp->v_type == VCHR || vp->v_type == VBLK) 1287 flags &= ~(WRITECLOSE|FORCECLOSE); 1288 1289 /* 1290 * If WRITECLOSE is set, flush out unlinked but still open 1291 * files (even if open only for reading) and regular file 1292 * vnodes open for writing. 1293 */ 1294 if ((flags & WRITECLOSE) && 1295 (vp->v_type == VNON || 1296 (VOP_GETATTR(vp, &vattr) == 0 && 1297 vattr.va_nlink > 0)) && 1298 (vp->v_writecount == 0 || vp->v_type != VREG)) { 1299 return(0); 1300 } 1301 1302 /* 1303 * If we are the only holder (refcnt of 1) or the vnode is in 1304 * termination (refcnt < 0), we can vgone the vnode. 1305 */ 1306 if (VREFCNT(vp) <= 1) { 1307 vgone_vxlocked(vp); 1308 return(0); 1309 } 1310 1311 /* 1312 * If FORCECLOSE is set, forcibly destroy the vnode and then move 1313 * it to a dummymount structure so vop_*() functions don't deref 1314 * a NULL pointer. 1315 */ 1316 if (flags & FORCECLOSE) { 1317 vhold(vp); 1318 vgone_vxlocked(vp); 1319 if (vp->v_mount == NULL) 1320 insmntque(vp, &dummymount); 1321 vdrop(vp); 1322 return(0); 1323 } 1324 if (vp->v_type == VCHR || vp->v_type == VBLK) 1325 kprintf("vflush: Warning, cannot destroy busy device vnode\n"); 1326 #ifdef DIAGNOSTIC 1327 if (busyprt) 1328 vprint("vflush: busy vnode", vp); 1329 #endif 1330 ++info->busy; 1331 return(0); 1332 } 1333 1334 void 1335 add_bio_ops(struct bio_ops *ops) 1336 { 1337 TAILQ_INSERT_TAIL(&bio_ops_list, ops, entry); 1338 } 1339 1340 void 1341 rem_bio_ops(struct bio_ops *ops) 1342 { 1343 TAILQ_REMOVE(&bio_ops_list, ops, entry); 1344 } 1345 1346 /* 1347 * This calls the bio_ops io_sync function either for a mount point 1348 * or generally. 1349 * 1350 * WARNING: softdeps is weirdly coded and just isn't happy unless 1351 * io_sync is called with a NULL mount from the general syncing code. 1352 */ 1353 void 1354 bio_ops_sync(struct mount *mp) 1355 { 1356 struct bio_ops *ops; 1357 1358 if (mp) { 1359 if ((ops = mp->mnt_bioops) != NULL) 1360 ops->io_sync(mp); 1361 } else { 1362 TAILQ_FOREACH(ops, &bio_ops_list, entry) { 1363 ops->io_sync(NULL); 1364 } 1365 } 1366 } 1367 1368 /* 1369 * Lookup a mount point by nch 1370 */ 1371 struct mount * 1372 mount_get_by_nc(struct namecache *ncp) 1373 { 1374 struct mount *mp = NULL; 1375 1376 lwkt_gettoken(&mountlist_token); 1377 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 1378 if (ncp == mp->mnt_ncmountpt.ncp) 1379 break; 1380 } 1381 lwkt_reltoken(&mountlist_token); 1382 return (mp); 1383 } 1384 1385