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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 /* 38 * External virtual filesystem routines 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_ddb.h" 45 #include "opt_watchdog.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/condvar.h> 52 #include <sys/conf.h> 53 #include <sys/dirent.h> 54 #include <sys/event.h> 55 #include <sys/eventhandler.h> 56 #include <sys/extattr.h> 57 #include <sys/file.h> 58 #include <sys/fcntl.h> 59 #include <sys/jail.h> 60 #include <sys/kdb.h> 61 #include <sys/kernel.h> 62 #include <sys/kthread.h> 63 #include <sys/lockf.h> 64 #include <sys/malloc.h> 65 #include <sys/mount.h> 66 #include <sys/namei.h> 67 #include <sys/priv.h> 68 #include <sys/reboot.h> 69 #include <sys/sched.h> 70 #include <sys/sleepqueue.h> 71 #include <sys/stat.h> 72 #include <sys/sysctl.h> 73 #include <sys/syslog.h> 74 #include <sys/vmmeter.h> 75 #include <sys/vnode.h> 76 #ifdef SW_WATCHDOG 77 #include <sys/watchdog.h> 78 #endif 79 80 #include <machine/stdarg.h> 81 82 #include <security/mac/mac_framework.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_object.h> 86 #include <vm/vm_extern.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_page.h> 90 #include <vm/vm_kern.h> 91 #include <vm/uma.h> 92 93 #ifdef DDB 94 #include <ddb/ddb.h> 95 #endif 96 97 #define WI_MPSAFEQ 0 98 #define WI_GIANTQ 1 99 100 static void delmntque(struct vnode *vp); 101 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, 102 int slpflag, int slptimeo); 103 static void syncer_shutdown(void *arg, int howto); 104 static int vtryrecycle(struct vnode *vp); 105 static void vbusy(struct vnode *vp); 106 static void vinactive(struct vnode *, struct thread *); 107 static void v_incr_usecount(struct vnode *); 108 static void v_decr_usecount(struct vnode *); 109 static void v_decr_useonly(struct vnode *); 110 static void v_upgrade_usecount(struct vnode *); 111 static void vfree(struct vnode *); 112 static void vnlru_free(int); 113 static void vgonel(struct vnode *); 114 static void vfs_knllock(void *arg); 115 static void vfs_knlunlock(void *arg); 116 static void vfs_knl_assert_locked(void *arg); 117 static void vfs_knl_assert_unlocked(void *arg); 118 static void destroy_vpollinfo(struct vpollinfo *vi); 119 120 /* 121 * Number of vnodes in existence. Increased whenever getnewvnode() 122 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed 123 * vnode. 124 */ 125 static unsigned long numvnodes; 126 127 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, 128 "Number of vnodes in existence"); 129 130 /* 131 * Conversion tables for conversion from vnode types to inode formats 132 * and back. 133 */ 134 enum vtype iftovt_tab[16] = { 135 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 136 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 137 }; 138 int vttoif_tab[10] = { 139 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 140 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT 141 }; 142 143 /* 144 * List of vnodes that are ready for recycling. 145 */ 146 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 147 148 /* 149 * Free vnode target. Free vnodes may simply be files which have been stat'd 150 * but not read. This is somewhat common, and a small cache of such files 151 * should be kept to avoid recreation costs. 152 */ 153 static u_long wantfreevnodes; 154 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 155 /* Number of vnodes in the free list. */ 156 static u_long freevnodes; 157 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, 158 "Number of vnodes in the free list"); 159 160 static int vlru_allow_cache_src; 161 SYSCTL_INT(_vfs, OID_AUTO, vlru_allow_cache_src, CTLFLAG_RW, 162 &vlru_allow_cache_src, 0, "Allow vlru to reclaim source vnode"); 163 164 /* 165 * Various variables used for debugging the new implementation of 166 * reassignbuf(). 167 * XXX these are probably of (very) limited utility now. 168 */ 169 static int reassignbufcalls; 170 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, 171 "Number of calls to reassignbuf"); 172 173 /* 174 * Cache for the mount type id assigned to NFS. This is used for 175 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 176 */ 177 int nfs_mount_type = -1; 178 179 /* To keep more than one thread at a time from running vfs_getnewfsid */ 180 static struct mtx mntid_mtx; 181 182 /* 183 * Lock for any access to the following: 184 * vnode_free_list 185 * numvnodes 186 * freevnodes 187 */ 188 static struct mtx vnode_free_list_mtx; 189 190 /* Publicly exported FS */ 191 struct nfs_public nfs_pub; 192 193 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 194 static uma_zone_t vnode_zone; 195 static uma_zone_t vnodepoll_zone; 196 197 /* 198 * The workitem queue. 199 * 200 * It is useful to delay writes of file data and filesystem metadata 201 * for tens of seconds so that quickly created and deleted files need 202 * not waste disk bandwidth being created and removed. To realize this, 203 * we append vnodes to a "workitem" queue. When running with a soft 204 * updates implementation, most pending metadata dependencies should 205 * not wait for more than a few seconds. Thus, mounted on block devices 206 * are delayed only about a half the time that file data is delayed. 207 * Similarly, directory updates are more critical, so are only delayed 208 * about a third the time that file data is delayed. Thus, there are 209 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 210 * one each second (driven off the filesystem syncer process). The 211 * syncer_delayno variable indicates the next queue that is to be processed. 212 * Items that need to be processed soon are placed in this queue: 213 * 214 * syncer_workitem_pending[syncer_delayno] 215 * 216 * A delay of fifteen seconds is done by placing the request fifteen 217 * entries later in the queue: 218 * 219 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 220 * 221 */ 222 static int syncer_delayno; 223 static long syncer_mask; 224 LIST_HEAD(synclist, bufobj); 225 static struct synclist *syncer_workitem_pending[2]; 226 /* 227 * The sync_mtx protects: 228 * bo->bo_synclist 229 * sync_vnode_count 230 * syncer_delayno 231 * syncer_state 232 * syncer_workitem_pending 233 * syncer_worklist_len 234 * rushjob 235 */ 236 static struct mtx sync_mtx; 237 static struct cv sync_wakeup; 238 239 #define SYNCER_MAXDELAY 32 240 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 241 static int syncdelay = 30; /* max time to delay syncing data */ 242 static int filedelay = 30; /* time to delay syncing files */ 243 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, 244 "Time to delay syncing files (in seconds)"); 245 static int dirdelay = 29; /* time to delay syncing directories */ 246 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, 247 "Time to delay syncing directories (in seconds)"); 248 static int metadelay = 28; /* time to delay syncing metadata */ 249 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, 250 "Time to delay syncing metadata (in seconds)"); 251 static int rushjob; /* number of slots to run ASAP */ 252 static int stat_rush_requests; /* number of times I/O speeded up */ 253 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, 254 "Number of times I/O speeded up (rush requests)"); 255 256 /* 257 * When shutting down the syncer, run it at four times normal speed. 258 */ 259 #define SYNCER_SHUTDOWN_SPEEDUP 4 260 static int sync_vnode_count; 261 static int syncer_worklist_len; 262 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } 263 syncer_state; 264 265 /* 266 * Number of vnodes we want to exist at any one time. This is mostly used 267 * to size hash tables in vnode-related code. It is normally not used in 268 * getnewvnode(), as wantfreevnodes is normally nonzero.) 269 * 270 * XXX desiredvnodes is historical cruft and should not exist. 271 */ 272 int desiredvnodes; 273 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 274 &desiredvnodes, 0, "Maximum number of vnodes"); 275 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 276 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)"); 277 static int vnlru_nowhere; 278 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, 279 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); 280 281 /* 282 * Macros to control when a vnode is freed and recycled. All require 283 * the vnode interlock. 284 */ 285 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 286 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) 287 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt) 288 289 290 /* 291 * Initialize the vnode management data structures. 292 * 293 * Reevaluate the following cap on the number of vnodes after the physical 294 * memory size exceeds 512GB. In the limit, as the physical memory size 295 * grows, the ratio of physical pages to vnodes approaches sixteen to one. 296 */ 297 #ifndef MAXVNODES_MAX 298 #define MAXVNODES_MAX (512 * (1024 * 1024 * 1024 / (int)PAGE_SIZE / 16)) 299 #endif 300 static void 301 vntblinit(void *dummy __unused) 302 { 303 int physvnodes, virtvnodes; 304 305 /* 306 * Desiredvnodes is a function of the physical memory size and the 307 * kernel's heap size. Generally speaking, it scales with the 308 * physical memory size. The ratio of desiredvnodes to physical pages 309 * is one to four until desiredvnodes exceeds 98,304. Thereafter, the 310 * marginal ratio of desiredvnodes to physical pages is one to 311 * sixteen. However, desiredvnodes is limited by the kernel's heap 312 * size. The memory required by desiredvnodes vnodes and vm objects 313 * may not exceed one seventh of the kernel's heap size. 314 */ 315 physvnodes = maxproc + cnt.v_page_count / 16 + 3 * min(98304 * 4, 316 cnt.v_page_count) / 16; 317 virtvnodes = vm_kmem_size / (7 * (sizeof(struct vm_object) + 318 sizeof(struct vnode))); 319 desiredvnodes = min(physvnodes, virtvnodes); 320 if (desiredvnodes > MAXVNODES_MAX) { 321 if (bootverbose) 322 printf("Reducing kern.maxvnodes %d -> %d\n", 323 desiredvnodes, MAXVNODES_MAX); 324 desiredvnodes = MAXVNODES_MAX; 325 } 326 wantfreevnodes = desiredvnodes / 4; 327 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 328 TAILQ_INIT(&vnode_free_list); 329 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 330 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 331 NULL, NULL, UMA_ALIGN_PTR, 0); 332 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 333 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 334 /* 335 * Initialize the filesystem syncer. 336 */ 337 syncer_workitem_pending[WI_MPSAFEQ] = hashinit(syncer_maxdelay, M_VNODE, 338 &syncer_mask); 339 syncer_workitem_pending[WI_GIANTQ] = hashinit(syncer_maxdelay, M_VNODE, 340 &syncer_mask); 341 syncer_maxdelay = syncer_mask + 1; 342 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); 343 cv_init(&sync_wakeup, "syncer"); 344 } 345 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); 346 347 348 /* 349 * Mark a mount point as busy. Used to synchronize access and to delay 350 * unmounting. Eventually, mountlist_mtx is not released on failure. 351 * 352 * vfs_busy() is a custom lock, it can block the caller. 353 * vfs_busy() only sleeps if the unmount is active on the mount point. 354 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any 355 * vnode belonging to mp. 356 * 357 * Lookup uses vfs_busy() to traverse mount points. 358 * root fs var fs 359 * / vnode lock A / vnode lock (/var) D 360 * /var vnode lock B /log vnode lock(/var/log) E 361 * vfs_busy lock C vfs_busy lock F 362 * 363 * Within each file system, the lock order is C->A->B and F->D->E. 364 * 365 * When traversing across mounts, the system follows that lock order: 366 * 367 * C->A->B 368 * | 369 * +->F->D->E 370 * 371 * The lookup() process for namei("/var") illustrates the process: 372 * VOP_LOOKUP() obtains B while A is held 373 * vfs_busy() obtains a shared lock on F while A and B are held 374 * vput() releases lock on B 375 * vput() releases lock on A 376 * VFS_ROOT() obtains lock on D while shared lock on F is held 377 * vfs_unbusy() releases shared lock on F 378 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. 379 * Attempt to lock A (instead of vp_crossmp) while D is held would 380 * violate the global order, causing deadlocks. 381 * 382 * dounmount() locks B while F is drained. 383 */ 384 int 385 vfs_busy(struct mount *mp, int flags) 386 { 387 388 MPASS((flags & ~MBF_MASK) == 0); 389 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); 390 391 MNT_ILOCK(mp); 392 MNT_REF(mp); 393 /* 394 * If mount point is currenly being unmounted, sleep until the 395 * mount point fate is decided. If thread doing the unmounting fails, 396 * it will clear MNTK_UNMOUNT flag before waking us up, indicating 397 * that this mount point has survived the unmount attempt and vfs_busy 398 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE 399 * flag in addition to MNTK_UNMOUNT, indicating that mount point is 400 * about to be really destroyed. vfs_busy needs to release its 401 * reference on the mount point in this case and return with ENOENT, 402 * telling the caller that mount mount it tried to busy is no longer 403 * valid. 404 */ 405 while (mp->mnt_kern_flag & MNTK_UNMOUNT) { 406 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { 407 MNT_REL(mp); 408 MNT_IUNLOCK(mp); 409 CTR1(KTR_VFS, "%s: failed busying before sleeping", 410 __func__); 411 return (ENOENT); 412 } 413 if (flags & MBF_MNTLSTLOCK) 414 mtx_unlock(&mountlist_mtx); 415 mp->mnt_kern_flag |= MNTK_MWAIT; 416 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); 417 if (flags & MBF_MNTLSTLOCK) 418 mtx_lock(&mountlist_mtx); 419 MNT_ILOCK(mp); 420 } 421 if (flags & MBF_MNTLSTLOCK) 422 mtx_unlock(&mountlist_mtx); 423 mp->mnt_lockref++; 424 MNT_IUNLOCK(mp); 425 return (0); 426 } 427 428 /* 429 * Free a busy filesystem. 430 */ 431 void 432 vfs_unbusy(struct mount *mp) 433 { 434 435 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 436 MNT_ILOCK(mp); 437 MNT_REL(mp); 438 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); 439 mp->mnt_lockref--; 440 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { 441 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); 442 CTR1(KTR_VFS, "%s: waking up waiters", __func__); 443 mp->mnt_kern_flag &= ~MNTK_DRAINING; 444 wakeup(&mp->mnt_lockref); 445 } 446 MNT_IUNLOCK(mp); 447 } 448 449 /* 450 * Lookup a mount point by filesystem identifier. 451 */ 452 struct mount * 453 vfs_getvfs(fsid_t *fsid) 454 { 455 struct mount *mp; 456 457 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 458 mtx_lock(&mountlist_mtx); 459 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 460 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 461 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 462 vfs_ref(mp); 463 mtx_unlock(&mountlist_mtx); 464 return (mp); 465 } 466 } 467 mtx_unlock(&mountlist_mtx); 468 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 469 return ((struct mount *) 0); 470 } 471 472 /* 473 * Lookup a mount point by filesystem identifier, busying it before 474 * returning. 475 */ 476 struct mount * 477 vfs_busyfs(fsid_t *fsid) 478 { 479 struct mount *mp; 480 int error; 481 482 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); 483 mtx_lock(&mountlist_mtx); 484 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 485 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 486 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 487 error = vfs_busy(mp, MBF_MNTLSTLOCK); 488 if (error) { 489 mtx_unlock(&mountlist_mtx); 490 return (NULL); 491 } 492 return (mp); 493 } 494 } 495 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); 496 mtx_unlock(&mountlist_mtx); 497 return ((struct mount *) 0); 498 } 499 500 /* 501 * Check if a user can access privileged mount options. 502 */ 503 int 504 vfs_suser(struct mount *mp, struct thread *td) 505 { 506 int error; 507 508 /* 509 * If the thread is jailed, but this is not a jail-friendly file 510 * system, deny immediately. 511 */ 512 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred)) 513 return (EPERM); 514 515 /* 516 * If the file system was mounted outside the jail of the calling 517 * thread, deny immediately. 518 */ 519 if (prison_check(td->td_ucred, mp->mnt_cred) != 0) 520 return (EPERM); 521 522 /* 523 * If file system supports delegated administration, we don't check 524 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified 525 * by the file system itself. 526 * If this is not the user that did original mount, we check for 527 * the PRIV_VFS_MOUNT_OWNER privilege. 528 */ 529 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && 530 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 531 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0) 532 return (error); 533 } 534 return (0); 535 } 536 537 /* 538 * Get a new unique fsid. Try to make its val[0] unique, since this value 539 * will be used to create fake device numbers for stat(). Also try (but 540 * not so hard) make its val[0] unique mod 2^16, since some emulators only 541 * support 16-bit device numbers. We end up with unique val[0]'s for the 542 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 543 * 544 * Keep in mind that several mounts may be running in parallel. Starting 545 * the search one past where the previous search terminated is both a 546 * micro-optimization and a defense against returning the same fsid to 547 * different mounts. 548 */ 549 void 550 vfs_getnewfsid(struct mount *mp) 551 { 552 static uint16_t mntid_base; 553 struct mount *nmp; 554 fsid_t tfsid; 555 int mtype; 556 557 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 558 mtx_lock(&mntid_mtx); 559 mtype = mp->mnt_vfc->vfc_typenum; 560 tfsid.val[1] = mtype; 561 mtype = (mtype & 0xFF) << 24; 562 for (;;) { 563 tfsid.val[0] = makedev(255, 564 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 565 mntid_base++; 566 if ((nmp = vfs_getvfs(&tfsid)) == NULL) 567 break; 568 vfs_rel(nmp); 569 } 570 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 571 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 572 mtx_unlock(&mntid_mtx); 573 } 574 575 /* 576 * Knob to control the precision of file timestamps: 577 * 578 * 0 = seconds only; nanoseconds zeroed. 579 * 1 = seconds and nanoseconds, accurate within 1/HZ. 580 * 2 = seconds and nanoseconds, truncated to microseconds. 581 * >=3 = seconds and nanoseconds, maximum precision. 582 */ 583 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 584 585 static int timestamp_precision = TSP_SEC; 586 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 587 ×tamp_precision, 0, "File timestamp precision (0: seconds, " 588 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, " 589 "3+: sec + ns (max. precision))"); 590 591 /* 592 * Get a current timestamp. 593 */ 594 void 595 vfs_timestamp(struct timespec *tsp) 596 { 597 struct timeval tv; 598 599 switch (timestamp_precision) { 600 case TSP_SEC: 601 tsp->tv_sec = time_second; 602 tsp->tv_nsec = 0; 603 break; 604 case TSP_HZ: 605 getnanotime(tsp); 606 break; 607 case TSP_USEC: 608 microtime(&tv); 609 TIMEVAL_TO_TIMESPEC(&tv, tsp); 610 break; 611 case TSP_NSEC: 612 default: 613 nanotime(tsp); 614 break; 615 } 616 } 617 618 /* 619 * Set vnode attributes to VNOVAL 620 */ 621 void 622 vattr_null(struct vattr *vap) 623 { 624 625 vap->va_type = VNON; 626 vap->va_size = VNOVAL; 627 vap->va_bytes = VNOVAL; 628 vap->va_mode = VNOVAL; 629 vap->va_nlink = VNOVAL; 630 vap->va_uid = VNOVAL; 631 vap->va_gid = VNOVAL; 632 vap->va_fsid = VNOVAL; 633 vap->va_fileid = VNOVAL; 634 vap->va_blocksize = VNOVAL; 635 vap->va_rdev = VNOVAL; 636 vap->va_atime.tv_sec = VNOVAL; 637 vap->va_atime.tv_nsec = VNOVAL; 638 vap->va_mtime.tv_sec = VNOVAL; 639 vap->va_mtime.tv_nsec = VNOVAL; 640 vap->va_ctime.tv_sec = VNOVAL; 641 vap->va_ctime.tv_nsec = VNOVAL; 642 vap->va_birthtime.tv_sec = VNOVAL; 643 vap->va_birthtime.tv_nsec = VNOVAL; 644 vap->va_flags = VNOVAL; 645 vap->va_gen = VNOVAL; 646 vap->va_vaflags = 0; 647 } 648 649 /* 650 * This routine is called when we have too many vnodes. It attempts 651 * to free <count> vnodes and will potentially free vnodes that still 652 * have VM backing store (VM backing store is typically the cause 653 * of a vnode blowout so we want to do this). Therefore, this operation 654 * is not considered cheap. 655 * 656 * A number of conditions may prevent a vnode from being reclaimed. 657 * the buffer cache may have references on the vnode, a directory 658 * vnode may still have references due to the namei cache representing 659 * underlying files, or the vnode may be in active use. It is not 660 * desireable to reuse such vnodes. These conditions may cause the 661 * number of vnodes to reach some minimum value regardless of what 662 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 663 */ 664 static int 665 vlrureclaim(struct mount *mp) 666 { 667 struct vnode *vp; 668 int done; 669 int trigger; 670 int usevnodes; 671 int count; 672 673 /* 674 * Calculate the trigger point, don't allow user 675 * screwups to blow us up. This prevents us from 676 * recycling vnodes with lots of resident pages. We 677 * aren't trying to free memory, we are trying to 678 * free vnodes. 679 */ 680 usevnodes = desiredvnodes; 681 if (usevnodes <= 0) 682 usevnodes = 1; 683 trigger = cnt.v_page_count * 2 / usevnodes; 684 done = 0; 685 vn_start_write(NULL, &mp, V_WAIT); 686 MNT_ILOCK(mp); 687 count = mp->mnt_nvnodelistsize / 10 + 1; 688 while (count != 0) { 689 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 690 while (vp != NULL && vp->v_type == VMARKER) 691 vp = TAILQ_NEXT(vp, v_nmntvnodes); 692 if (vp == NULL) 693 break; 694 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 695 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 696 --count; 697 if (!VI_TRYLOCK(vp)) 698 goto next_iter; 699 /* 700 * If it's been deconstructed already, it's still 701 * referenced, or it exceeds the trigger, skip it. 702 */ 703 if (vp->v_usecount || 704 (!vlru_allow_cache_src && 705 !LIST_EMPTY(&(vp)->v_cache_src)) || 706 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && 707 vp->v_object->resident_page_count > trigger)) { 708 VI_UNLOCK(vp); 709 goto next_iter; 710 } 711 MNT_IUNLOCK(mp); 712 vholdl(vp); 713 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) { 714 vdrop(vp); 715 goto next_iter_mntunlocked; 716 } 717 VI_LOCK(vp); 718 /* 719 * v_usecount may have been bumped after VOP_LOCK() dropped 720 * the vnode interlock and before it was locked again. 721 * 722 * It is not necessary to recheck VI_DOOMED because it can 723 * only be set by another thread that holds both the vnode 724 * lock and vnode interlock. If another thread has the 725 * vnode lock before we get to VOP_LOCK() and obtains the 726 * vnode interlock after VOP_LOCK() drops the vnode 727 * interlock, the other thread will be unable to drop the 728 * vnode lock before our VOP_LOCK() call fails. 729 */ 730 if (vp->v_usecount || 731 (!vlru_allow_cache_src && 732 !LIST_EMPTY(&(vp)->v_cache_src)) || 733 (vp->v_object != NULL && 734 vp->v_object->resident_page_count > trigger)) { 735 VOP_UNLOCK(vp, LK_INTERLOCK); 736 goto next_iter_mntunlocked; 737 } 738 KASSERT((vp->v_iflag & VI_DOOMED) == 0, 739 ("VI_DOOMED unexpectedly detected in vlrureclaim()")); 740 vgonel(vp); 741 VOP_UNLOCK(vp, 0); 742 vdropl(vp); 743 done++; 744 next_iter_mntunlocked: 745 if (!should_yield()) 746 goto relock_mnt; 747 goto yield; 748 next_iter: 749 if (!should_yield()) 750 continue; 751 MNT_IUNLOCK(mp); 752 yield: 753 kern_yield(PRI_UNCHANGED); 754 relock_mnt: 755 MNT_ILOCK(mp); 756 } 757 MNT_IUNLOCK(mp); 758 vn_finished_write(mp); 759 return done; 760 } 761 762 /* 763 * Attempt to keep the free list at wantfreevnodes length. 764 */ 765 static void 766 vnlru_free(int count) 767 { 768 struct vnode *vp; 769 int vfslocked; 770 771 mtx_assert(&vnode_free_list_mtx, MA_OWNED); 772 for (; count > 0; count--) { 773 vp = TAILQ_FIRST(&vnode_free_list); 774 /* 775 * The list can be modified while the free_list_mtx 776 * has been dropped and vp could be NULL here. 777 */ 778 if (!vp) 779 break; 780 VNASSERT(vp->v_op != NULL, vp, 781 ("vnlru_free: vnode already reclaimed.")); 782 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 783 /* 784 * Don't recycle if we can't get the interlock. 785 */ 786 if (!VI_TRYLOCK(vp)) { 787 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 788 continue; 789 } 790 VNASSERT(VCANRECYCLE(vp), vp, 791 ("vp inconsistent on freelist")); 792 freevnodes--; 793 vp->v_iflag &= ~VI_FREE; 794 vholdl(vp); 795 mtx_unlock(&vnode_free_list_mtx); 796 VI_UNLOCK(vp); 797 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 798 vtryrecycle(vp); 799 VFS_UNLOCK_GIANT(vfslocked); 800 /* 801 * If the recycled succeeded this vdrop will actually free 802 * the vnode. If not it will simply place it back on 803 * the free list. 804 */ 805 vdrop(vp); 806 mtx_lock(&vnode_free_list_mtx); 807 } 808 } 809 /* 810 * Attempt to recycle vnodes in a context that is always safe to block. 811 * Calling vlrurecycle() from the bowels of filesystem code has some 812 * interesting deadlock problems. 813 */ 814 static struct proc *vnlruproc; 815 static int vnlruproc_sig; 816 817 static void 818 vnlru_proc(void) 819 { 820 struct mount *mp, *nmp; 821 int done, vfslocked; 822 struct proc *p = vnlruproc; 823 824 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 825 SHUTDOWN_PRI_FIRST); 826 827 for (;;) { 828 kproc_suspend_check(p); 829 mtx_lock(&vnode_free_list_mtx); 830 if (freevnodes > wantfreevnodes) 831 vnlru_free(freevnodes - wantfreevnodes); 832 if (numvnodes <= desiredvnodes * 9 / 10) { 833 vnlruproc_sig = 0; 834 wakeup(&vnlruproc_sig); 835 msleep(vnlruproc, &vnode_free_list_mtx, 836 PVFS|PDROP, "vlruwt", hz); 837 continue; 838 } 839 mtx_unlock(&vnode_free_list_mtx); 840 done = 0; 841 mtx_lock(&mountlist_mtx); 842 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 843 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { 844 nmp = TAILQ_NEXT(mp, mnt_list); 845 continue; 846 } 847 vfslocked = VFS_LOCK_GIANT(mp); 848 done += vlrureclaim(mp); 849 VFS_UNLOCK_GIANT(vfslocked); 850 mtx_lock(&mountlist_mtx); 851 nmp = TAILQ_NEXT(mp, mnt_list); 852 vfs_unbusy(mp); 853 } 854 mtx_unlock(&mountlist_mtx); 855 if (done == 0) { 856 #if 0 857 /* These messages are temporary debugging aids */ 858 if (vnlru_nowhere < 5) 859 printf("vnlru process getting nowhere..\n"); 860 else if (vnlru_nowhere == 5) 861 printf("vnlru process messages stopped.\n"); 862 #endif 863 vnlru_nowhere++; 864 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 865 } else 866 kern_yield(PRI_UNCHANGED); 867 } 868 } 869 870 static struct kproc_desc vnlru_kp = { 871 "vnlru", 872 vnlru_proc, 873 &vnlruproc 874 }; 875 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, 876 &vnlru_kp); 877 878 /* 879 * Routines having to do with the management of the vnode table. 880 */ 881 882 void 883 vdestroy(struct vnode *vp) 884 { 885 struct bufobj *bo; 886 887 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 888 mtx_lock(&vnode_free_list_mtx); 889 numvnodes--; 890 mtx_unlock(&vnode_free_list_mtx); 891 bo = &vp->v_bufobj; 892 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, 893 ("cleaned vnode still on the free list.")); 894 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); 895 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); 896 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); 897 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); 898 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); 899 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); 900 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL")); 901 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); 902 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL")); 903 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); 904 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); 905 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); 906 VI_UNLOCK(vp); 907 #ifdef MAC 908 mac_vnode_destroy(vp); 909 #endif 910 if (vp->v_pollinfo != NULL) 911 destroy_vpollinfo(vp->v_pollinfo); 912 #ifdef INVARIANTS 913 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */ 914 vp->v_op = NULL; 915 #endif 916 lockdestroy(vp->v_vnlock); 917 mtx_destroy(&vp->v_interlock); 918 mtx_destroy(BO_MTX(bo)); 919 uma_zfree(vnode_zone, vp); 920 } 921 922 /* 923 * Try to recycle a freed vnode. We abort if anyone picks up a reference 924 * before we actually vgone(). This function must be called with the vnode 925 * held to prevent the vnode from being returned to the free list midway 926 * through vgone(). 927 */ 928 static int 929 vtryrecycle(struct vnode *vp) 930 { 931 struct mount *vnmp; 932 933 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 934 VNASSERT(vp->v_holdcnt, vp, 935 ("vtryrecycle: Recycling vp %p without a reference.", vp)); 936 /* 937 * This vnode may found and locked via some other list, if so we 938 * can't recycle it yet. 939 */ 940 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) { 941 CTR2(KTR_VFS, 942 "%s: impossible to recycle, vp %p lock is already held", 943 __func__, vp); 944 return (EWOULDBLOCK); 945 } 946 /* 947 * Don't recycle if its filesystem is being suspended. 948 */ 949 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { 950 VOP_UNLOCK(vp, 0); 951 CTR2(KTR_VFS, 952 "%s: impossible to recycle, cannot start the write for %p", 953 __func__, vp); 954 return (EBUSY); 955 } 956 /* 957 * If we got this far, we need to acquire the interlock and see if 958 * anyone picked up this vnode from another list. If not, we will 959 * mark it with DOOMED via vgonel() so that anyone who does find it 960 * will skip over it. 961 */ 962 VI_LOCK(vp); 963 if (vp->v_usecount) { 964 VOP_UNLOCK(vp, LK_INTERLOCK); 965 vn_finished_write(vnmp); 966 CTR2(KTR_VFS, 967 "%s: impossible to recycle, %p is already referenced", 968 __func__, vp); 969 return (EBUSY); 970 } 971 if ((vp->v_iflag & VI_DOOMED) == 0) 972 vgonel(vp); 973 VOP_UNLOCK(vp, LK_INTERLOCK); 974 vn_finished_write(vnmp); 975 return (0); 976 } 977 978 /* 979 * Return the next vnode from the free list. 980 */ 981 int 982 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, 983 struct vnode **vpp) 984 { 985 struct vnode *vp = NULL; 986 struct bufobj *bo; 987 988 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); 989 mtx_lock(&vnode_free_list_mtx); 990 /* 991 * Lend our context to reclaim vnodes if they've exceeded the max. 992 */ 993 if (freevnodes > wantfreevnodes) 994 vnlru_free(1); 995 /* 996 * Wait for available vnodes. 997 */ 998 if (numvnodes > desiredvnodes) { 999 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) { 1000 /* 1001 * File system is beeing suspended, we cannot risk a 1002 * deadlock here, so allocate new vnode anyway. 1003 */ 1004 if (freevnodes > wantfreevnodes) 1005 vnlru_free(freevnodes - wantfreevnodes); 1006 goto alloc; 1007 } 1008 if (vnlruproc_sig == 0) { 1009 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 1010 wakeup(vnlruproc); 1011 } 1012 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, 1013 "vlruwk", hz); 1014 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ 1015 if (numvnodes > desiredvnodes) { 1016 mtx_unlock(&vnode_free_list_mtx); 1017 return (ENFILE); 1018 } 1019 #endif 1020 } 1021 alloc: 1022 numvnodes++; 1023 mtx_unlock(&vnode_free_list_mtx); 1024 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); 1025 /* 1026 * Setup locks. 1027 */ 1028 vp->v_vnlock = &vp->v_lock; 1029 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 1030 /* 1031 * By default, don't allow shared locks unless filesystems 1032 * opt-in. 1033 */ 1034 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE); 1035 /* 1036 * Initialize bufobj. 1037 */ 1038 bo = &vp->v_bufobj; 1039 bo->__bo_vnode = vp; 1040 mtx_init(BO_MTX(bo), "bufobj interlock", NULL, MTX_DEF); 1041 bo->bo_ops = &buf_ops_bio; 1042 bo->bo_private = vp; 1043 TAILQ_INIT(&bo->bo_clean.bv_hd); 1044 TAILQ_INIT(&bo->bo_dirty.bv_hd); 1045 /* 1046 * Initialize namecache. 1047 */ 1048 LIST_INIT(&vp->v_cache_src); 1049 TAILQ_INIT(&vp->v_cache_dst); 1050 /* 1051 * Finalize various vnode identity bits. 1052 */ 1053 vp->v_type = VNON; 1054 vp->v_tag = tag; 1055 vp->v_op = vops; 1056 v_incr_usecount(vp); 1057 vp->v_data = NULL; 1058 #ifdef MAC 1059 mac_vnode_init(vp); 1060 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) 1061 mac_vnode_associate_singlelabel(mp, vp); 1062 else if (mp == NULL && vops != &dead_vnodeops) 1063 printf("NULL mp in getnewvnode()\n"); 1064 #endif 1065 if (mp != NULL) { 1066 bo->bo_bsize = mp->mnt_stat.f_iosize; 1067 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) 1068 vp->v_vflag |= VV_NOKNOTE; 1069 } 1070 1071 *vpp = vp; 1072 return (0); 1073 } 1074 1075 /* 1076 * Delete from old mount point vnode list, if on one. 1077 */ 1078 static void 1079 delmntque(struct vnode *vp) 1080 { 1081 struct mount *mp; 1082 1083 mp = vp->v_mount; 1084 if (mp == NULL) 1085 return; 1086 MNT_ILOCK(mp); 1087 vp->v_mount = NULL; 1088 VNASSERT(mp->mnt_nvnodelistsize > 0, vp, 1089 ("bad mount point vnode list size")); 1090 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1091 mp->mnt_nvnodelistsize--; 1092 MNT_REL(mp); 1093 MNT_IUNLOCK(mp); 1094 } 1095 1096 static void 1097 insmntque_stddtr(struct vnode *vp, void *dtr_arg) 1098 { 1099 1100 vp->v_data = NULL; 1101 vp->v_op = &dead_vnodeops; 1102 /* XXX non mp-safe fs may still call insmntque with vnode 1103 unlocked */ 1104 if (!VOP_ISLOCKED(vp)) 1105 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1106 vgone(vp); 1107 vput(vp); 1108 } 1109 1110 /* 1111 * Insert into list of vnodes for the new mount point, if available. 1112 */ 1113 int 1114 insmntque1(struct vnode *vp, struct mount *mp, 1115 void (*dtr)(struct vnode *, void *), void *dtr_arg) 1116 { 1117 int locked; 1118 1119 KASSERT(vp->v_mount == NULL, 1120 ("insmntque: vnode already on per mount vnode list")); 1121 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); 1122 #ifdef DEBUG_VFS_LOCKS 1123 if (!VFS_NEEDSGIANT(mp)) 1124 ASSERT_VOP_ELOCKED(vp, 1125 "insmntque: mp-safe fs and non-locked vp"); 1126 #endif 1127 MNT_ILOCK(mp); 1128 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 && 1129 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || 1130 mp->mnt_nvnodelistsize == 0)) { 1131 locked = VOP_ISLOCKED(vp); 1132 if (!locked || (locked == LK_EXCLUSIVE && 1133 (vp->v_vflag & VV_FORCEINSMQ) == 0)) { 1134 MNT_IUNLOCK(mp); 1135 if (dtr != NULL) 1136 dtr(vp, dtr_arg); 1137 return (EBUSY); 1138 } 1139 } 1140 vp->v_mount = mp; 1141 MNT_REF(mp); 1142 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 1143 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, 1144 ("neg mount point vnode list size")); 1145 mp->mnt_nvnodelistsize++; 1146 MNT_IUNLOCK(mp); 1147 return (0); 1148 } 1149 1150 int 1151 insmntque(struct vnode *vp, struct mount *mp) 1152 { 1153 1154 return (insmntque1(vp, mp, insmntque_stddtr, NULL)); 1155 } 1156 1157 /* 1158 * Flush out and invalidate all buffers associated with a bufobj 1159 * Called with the underlying object locked. 1160 */ 1161 int 1162 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo) 1163 { 1164 int error; 1165 1166 BO_LOCK(bo); 1167 if (flags & V_SAVE) { 1168 error = bufobj_wwait(bo, slpflag, slptimeo); 1169 if (error) { 1170 BO_UNLOCK(bo); 1171 return (error); 1172 } 1173 if (bo->bo_dirty.bv_cnt > 0) { 1174 BO_UNLOCK(bo); 1175 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0) 1176 return (error); 1177 /* 1178 * XXX We could save a lock/unlock if this was only 1179 * enabled under INVARIANTS 1180 */ 1181 BO_LOCK(bo); 1182 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 1183 panic("vinvalbuf: dirty bufs"); 1184 } 1185 } 1186 /* 1187 * If you alter this loop please notice that interlock is dropped and 1188 * reacquired in flushbuflist. Special care is needed to ensure that 1189 * no race conditions occur from this. 1190 */ 1191 do { 1192 error = flushbuflist(&bo->bo_clean, 1193 flags, bo, slpflag, slptimeo); 1194 if (error == 0) 1195 error = flushbuflist(&bo->bo_dirty, 1196 flags, bo, slpflag, slptimeo); 1197 if (error != 0 && error != EAGAIN) { 1198 BO_UNLOCK(bo); 1199 return (error); 1200 } 1201 } while (error != 0); 1202 1203 /* 1204 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 1205 * have write I/O in-progress but if there is a VM object then the 1206 * VM object can also have read-I/O in-progress. 1207 */ 1208 do { 1209 bufobj_wwait(bo, 0, 0); 1210 BO_UNLOCK(bo); 1211 if (bo->bo_object != NULL) { 1212 VM_OBJECT_LOCK(bo->bo_object); 1213 vm_object_pip_wait(bo->bo_object, "bovlbx"); 1214 VM_OBJECT_UNLOCK(bo->bo_object); 1215 } 1216 BO_LOCK(bo); 1217 } while (bo->bo_numoutput > 0); 1218 BO_UNLOCK(bo); 1219 1220 /* 1221 * Destroy the copy in the VM cache, too. 1222 */ 1223 if (bo->bo_object != NULL && (flags & (V_ALT | V_NORMAL)) == 0) { 1224 VM_OBJECT_LOCK(bo->bo_object); 1225 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? 1226 OBJPR_CLEANONLY : 0); 1227 VM_OBJECT_UNLOCK(bo->bo_object); 1228 } 1229 1230 #ifdef INVARIANTS 1231 BO_LOCK(bo); 1232 if ((flags & (V_ALT | V_NORMAL)) == 0 && 1233 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) 1234 panic("vinvalbuf: flush failed"); 1235 BO_UNLOCK(bo); 1236 #endif 1237 return (0); 1238 } 1239 1240 /* 1241 * Flush out and invalidate all buffers associated with a vnode. 1242 * Called with the underlying object locked. 1243 */ 1244 int 1245 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo) 1246 { 1247 1248 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 1249 ASSERT_VOP_LOCKED(vp, "vinvalbuf"); 1250 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); 1251 } 1252 1253 /* 1254 * Flush out buffers on the specified list. 1255 * 1256 */ 1257 static int 1258 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, 1259 int slptimeo) 1260 { 1261 struct buf *bp, *nbp; 1262 int retval, error; 1263 daddr_t lblkno; 1264 b_xflags_t xflags; 1265 1266 ASSERT_BO_LOCKED(bo); 1267 1268 retval = 0; 1269 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { 1270 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || 1271 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { 1272 continue; 1273 } 1274 lblkno = 0; 1275 xflags = 0; 1276 if (nbp != NULL) { 1277 lblkno = nbp->b_lblkno; 1278 xflags = nbp->b_xflags & 1279 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); 1280 } 1281 retval = EAGAIN; 1282 error = BUF_TIMELOCK(bp, 1283 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), 1284 "flushbuf", slpflag, slptimeo); 1285 if (error) { 1286 BO_LOCK(bo); 1287 return (error != ENOLCK ? error : EAGAIN); 1288 } 1289 KASSERT(bp->b_bufobj == bo, 1290 ("bp %p wrong b_bufobj %p should be %p", 1291 bp, bp->b_bufobj, bo)); 1292 if (bp->b_bufobj != bo) { /* XXX: necessary ? */ 1293 BUF_UNLOCK(bp); 1294 BO_LOCK(bo); 1295 return (EAGAIN); 1296 } 1297 /* 1298 * XXX Since there are no node locks for NFS, I 1299 * believe there is a slight chance that a delayed 1300 * write will occur while sleeping just above, so 1301 * check for it. 1302 */ 1303 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 1304 (flags & V_SAVE)) { 1305 BO_LOCK(bo); 1306 bremfree(bp); 1307 BO_UNLOCK(bo); 1308 bp->b_flags |= B_ASYNC; 1309 bwrite(bp); 1310 BO_LOCK(bo); 1311 return (EAGAIN); /* XXX: why not loop ? */ 1312 } 1313 BO_LOCK(bo); 1314 bremfree(bp); 1315 BO_UNLOCK(bo); 1316 bp->b_flags |= (B_INVAL | B_RELBUF); 1317 bp->b_flags &= ~B_ASYNC; 1318 brelse(bp); 1319 BO_LOCK(bo); 1320 if (nbp != NULL && 1321 (nbp->b_bufobj != bo || 1322 nbp->b_lblkno != lblkno || 1323 (nbp->b_xflags & 1324 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) 1325 break; /* nbp invalid */ 1326 } 1327 return (retval); 1328 } 1329 1330 /* 1331 * Truncate a file's buffer and pages to a specified length. This 1332 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1333 * sync activity. 1334 */ 1335 int 1336 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, 1337 off_t length, int blksize) 1338 { 1339 struct buf *bp, *nbp; 1340 int anyfreed; 1341 int trunclbn; 1342 struct bufobj *bo; 1343 1344 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__, 1345 vp, cred, blksize, (uintmax_t)length); 1346 1347 /* 1348 * Round up to the *next* lbn. 1349 */ 1350 trunclbn = (length + blksize - 1) / blksize; 1351 1352 ASSERT_VOP_LOCKED(vp, "vtruncbuf"); 1353 restart: 1354 bo = &vp->v_bufobj; 1355 BO_LOCK(bo); 1356 anyfreed = 1; 1357 for (;anyfreed;) { 1358 anyfreed = 0; 1359 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { 1360 if (bp->b_lblkno < trunclbn) 1361 continue; 1362 if (BUF_LOCK(bp, 1363 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1364 BO_MTX(bo)) == ENOLCK) 1365 goto restart; 1366 1367 BO_LOCK(bo); 1368 bremfree(bp); 1369 BO_UNLOCK(bo); 1370 bp->b_flags |= (B_INVAL | B_RELBUF); 1371 bp->b_flags &= ~B_ASYNC; 1372 brelse(bp); 1373 anyfreed = 1; 1374 1375 BO_LOCK(bo); 1376 if (nbp != NULL && 1377 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1378 (nbp->b_vp != vp) || 1379 (nbp->b_flags & B_DELWRI))) { 1380 BO_UNLOCK(bo); 1381 goto restart; 1382 } 1383 } 1384 1385 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1386 if (bp->b_lblkno < trunclbn) 1387 continue; 1388 if (BUF_LOCK(bp, 1389 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1390 BO_MTX(bo)) == ENOLCK) 1391 goto restart; 1392 BO_LOCK(bo); 1393 bremfree(bp); 1394 BO_UNLOCK(bo); 1395 bp->b_flags |= (B_INVAL | B_RELBUF); 1396 bp->b_flags &= ~B_ASYNC; 1397 brelse(bp); 1398 anyfreed = 1; 1399 1400 BO_LOCK(bo); 1401 if (nbp != NULL && 1402 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1403 (nbp->b_vp != vp) || 1404 (nbp->b_flags & B_DELWRI) == 0)) { 1405 BO_UNLOCK(bo); 1406 goto restart; 1407 } 1408 } 1409 } 1410 1411 if (length > 0) { 1412 restartsync: 1413 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 1414 if (bp->b_lblkno > 0) 1415 continue; 1416 /* 1417 * Since we hold the vnode lock this should only 1418 * fail if we're racing with the buf daemon. 1419 */ 1420 if (BUF_LOCK(bp, 1421 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, 1422 BO_MTX(bo)) == ENOLCK) { 1423 goto restart; 1424 } 1425 VNASSERT((bp->b_flags & B_DELWRI), vp, 1426 ("buf(%p) on dirty queue without DELWRI", bp)); 1427 1428 BO_LOCK(bo); 1429 bremfree(bp); 1430 BO_UNLOCK(bo); 1431 bawrite(bp); 1432 BO_LOCK(bo); 1433 goto restartsync; 1434 } 1435 } 1436 1437 bufobj_wwait(bo, 0, 0); 1438 BO_UNLOCK(bo); 1439 vnode_pager_setsize(vp, length); 1440 1441 return (0); 1442 } 1443 1444 /* 1445 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1446 * a vnode. 1447 * 1448 * NOTE: We have to deal with the special case of a background bitmap 1449 * buffer, a situation where two buffers will have the same logical 1450 * block offset. We want (1) only the foreground buffer to be accessed 1451 * in a lookup and (2) must differentiate between the foreground and 1452 * background buffer in the splay tree algorithm because the splay 1453 * tree cannot normally handle multiple entities with the same 'index'. 1454 * We accomplish this by adding differentiating flags to the splay tree's 1455 * numerical domain. 1456 */ 1457 static 1458 struct buf * 1459 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1460 { 1461 struct buf dummy; 1462 struct buf *lefttreemax, *righttreemin, *y; 1463 1464 if (root == NULL) 1465 return (NULL); 1466 lefttreemax = righttreemin = &dummy; 1467 for (;;) { 1468 if (lblkno < root->b_lblkno || 1469 (lblkno == root->b_lblkno && 1470 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1471 if ((y = root->b_left) == NULL) 1472 break; 1473 if (lblkno < y->b_lblkno) { 1474 /* Rotate right. */ 1475 root->b_left = y->b_right; 1476 y->b_right = root; 1477 root = y; 1478 if ((y = root->b_left) == NULL) 1479 break; 1480 } 1481 /* Link into the new root's right tree. */ 1482 righttreemin->b_left = root; 1483 righttreemin = root; 1484 } else if (lblkno > root->b_lblkno || 1485 (lblkno == root->b_lblkno && 1486 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1487 if ((y = root->b_right) == NULL) 1488 break; 1489 if (lblkno > y->b_lblkno) { 1490 /* Rotate left. */ 1491 root->b_right = y->b_left; 1492 y->b_left = root; 1493 root = y; 1494 if ((y = root->b_right) == NULL) 1495 break; 1496 } 1497 /* Link into the new root's left tree. */ 1498 lefttreemax->b_right = root; 1499 lefttreemax = root; 1500 } else { 1501 break; 1502 } 1503 root = y; 1504 } 1505 /* Assemble the new root. */ 1506 lefttreemax->b_right = root->b_left; 1507 righttreemin->b_left = root->b_right; 1508 root->b_left = dummy.b_right; 1509 root->b_right = dummy.b_left; 1510 return (root); 1511 } 1512 1513 static void 1514 buf_vlist_remove(struct buf *bp) 1515 { 1516 struct buf *root; 1517 struct bufv *bv; 1518 1519 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); 1520 ASSERT_BO_LOCKED(bp->b_bufobj); 1521 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != 1522 (BX_VNDIRTY|BX_VNCLEAN), 1523 ("buf_vlist_remove: Buf %p is on two lists", bp)); 1524 if (bp->b_xflags & BX_VNDIRTY) 1525 bv = &bp->b_bufobj->bo_dirty; 1526 else 1527 bv = &bp->b_bufobj->bo_clean; 1528 if (bp != bv->bv_root) { 1529 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1530 KASSERT(root == bp, ("splay lookup failed in remove")); 1531 } 1532 if (bp->b_left == NULL) { 1533 root = bp->b_right; 1534 } else { 1535 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1536 root->b_right = bp->b_right; 1537 } 1538 bv->bv_root = root; 1539 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); 1540 bv->bv_cnt--; 1541 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1542 } 1543 1544 /* 1545 * Add the buffer to the sorted clean or dirty block list using a 1546 * splay tree algorithm. 1547 * 1548 * NOTE: xflags is passed as a constant, optimizing this inline function! 1549 */ 1550 static void 1551 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags) 1552 { 1553 struct buf *root; 1554 struct bufv *bv; 1555 1556 ASSERT_BO_LOCKED(bo); 1557 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1558 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); 1559 bp->b_xflags |= xflags; 1560 if (xflags & BX_VNDIRTY) 1561 bv = &bo->bo_dirty; 1562 else 1563 bv = &bo->bo_clean; 1564 1565 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); 1566 if (root == NULL) { 1567 bp->b_left = NULL; 1568 bp->b_right = NULL; 1569 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); 1570 } else if (bp->b_lblkno < root->b_lblkno || 1571 (bp->b_lblkno == root->b_lblkno && 1572 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1573 bp->b_left = root->b_left; 1574 bp->b_right = root; 1575 root->b_left = NULL; 1576 TAILQ_INSERT_BEFORE(root, bp, b_bobufs); 1577 } else { 1578 bp->b_right = root->b_right; 1579 bp->b_left = root; 1580 root->b_right = NULL; 1581 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); 1582 } 1583 bv->bv_cnt++; 1584 bv->bv_root = bp; 1585 } 1586 1587 /* 1588 * Lookup a buffer using the splay tree. Note that we specifically avoid 1589 * shadow buffers used in background bitmap writes. 1590 * 1591 * This code isn't quite efficient as it could be because we are maintaining 1592 * two sorted lists and do not know which list the block resides in. 1593 * 1594 * During a "make buildworld" the desired buffer is found at one of 1595 * the roots more than 60% of the time. Thus, checking both roots 1596 * before performing either splay eliminates unnecessary splays on the 1597 * first tree splayed. 1598 */ 1599 struct buf * 1600 gbincore(struct bufobj *bo, daddr_t lblkno) 1601 { 1602 struct buf *bp; 1603 1604 ASSERT_BO_LOCKED(bo); 1605 if ((bp = bo->bo_clean.bv_root) != NULL && 1606 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1607 return (bp); 1608 if ((bp = bo->bo_dirty.bv_root) != NULL && 1609 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1610 return (bp); 1611 if ((bp = bo->bo_clean.bv_root) != NULL) { 1612 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); 1613 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1614 return (bp); 1615 } 1616 if ((bp = bo->bo_dirty.bv_root) != NULL) { 1617 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp); 1618 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1619 return (bp); 1620 } 1621 return (NULL); 1622 } 1623 1624 /* 1625 * Associate a buffer with a vnode. 1626 */ 1627 void 1628 bgetvp(struct vnode *vp, struct buf *bp) 1629 { 1630 struct bufobj *bo; 1631 1632 bo = &vp->v_bufobj; 1633 ASSERT_BO_LOCKED(bo); 1634 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); 1635 1636 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); 1637 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, 1638 ("bgetvp: bp already attached! %p", bp)); 1639 1640 vhold(vp); 1641 if (VFS_NEEDSGIANT(vp->v_mount) || bo->bo_flag & BO_NEEDSGIANT) 1642 bp->b_flags |= B_NEEDSGIANT; 1643 bp->b_vp = vp; 1644 bp->b_bufobj = bo; 1645 /* 1646 * Insert onto list for new vnode. 1647 */ 1648 buf_vlist_add(bp, bo, BX_VNCLEAN); 1649 } 1650 1651 /* 1652 * Disassociate a buffer from a vnode. 1653 */ 1654 void 1655 brelvp(struct buf *bp) 1656 { 1657 struct bufobj *bo; 1658 struct vnode *vp; 1659 1660 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); 1661 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1662 1663 /* 1664 * Delete from old vnode list, if on one. 1665 */ 1666 vp = bp->b_vp; /* XXX */ 1667 bo = bp->b_bufobj; 1668 BO_LOCK(bo); 1669 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1670 buf_vlist_remove(bp); 1671 else 1672 panic("brelvp: Buffer %p not on queue.", bp); 1673 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 1674 bo->bo_flag &= ~BO_ONWORKLST; 1675 mtx_lock(&sync_mtx); 1676 LIST_REMOVE(bo, bo_synclist); 1677 syncer_worklist_len--; 1678 mtx_unlock(&sync_mtx); 1679 } 1680 bp->b_flags &= ~B_NEEDSGIANT; 1681 bp->b_vp = NULL; 1682 bp->b_bufobj = NULL; 1683 BO_UNLOCK(bo); 1684 vdrop(vp); 1685 } 1686 1687 /* 1688 * Add an item to the syncer work queue. 1689 */ 1690 static void 1691 vn_syncer_add_to_worklist(struct bufobj *bo, int delay) 1692 { 1693 int queue, slot; 1694 1695 ASSERT_BO_LOCKED(bo); 1696 1697 mtx_lock(&sync_mtx); 1698 if (bo->bo_flag & BO_ONWORKLST) 1699 LIST_REMOVE(bo, bo_synclist); 1700 else { 1701 bo->bo_flag |= BO_ONWORKLST; 1702 syncer_worklist_len++; 1703 } 1704 1705 if (delay > syncer_maxdelay - 2) 1706 delay = syncer_maxdelay - 2; 1707 slot = (syncer_delayno + delay) & syncer_mask; 1708 1709 queue = VFS_NEEDSGIANT(bo->__bo_vnode->v_mount) ? WI_GIANTQ : 1710 WI_MPSAFEQ; 1711 LIST_INSERT_HEAD(&syncer_workitem_pending[queue][slot], bo, 1712 bo_synclist); 1713 mtx_unlock(&sync_mtx); 1714 } 1715 1716 static int 1717 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) 1718 { 1719 int error, len; 1720 1721 mtx_lock(&sync_mtx); 1722 len = syncer_worklist_len - sync_vnode_count; 1723 mtx_unlock(&sync_mtx); 1724 error = SYSCTL_OUT(req, &len, sizeof(len)); 1725 return (error); 1726 } 1727 1728 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, 1729 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); 1730 1731 static struct proc *updateproc; 1732 static void sched_sync(void); 1733 static struct kproc_desc up_kp = { 1734 "syncer", 1735 sched_sync, 1736 &updateproc 1737 }; 1738 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp); 1739 1740 static int 1741 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td) 1742 { 1743 struct vnode *vp; 1744 struct mount *mp; 1745 1746 *bo = LIST_FIRST(slp); 1747 if (*bo == NULL) 1748 return (0); 1749 vp = (*bo)->__bo_vnode; /* XXX */ 1750 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0) 1751 return (1); 1752 /* 1753 * We use vhold in case the vnode does not 1754 * successfully sync. vhold prevents the vnode from 1755 * going away when we unlock the sync_mtx so that 1756 * we can acquire the vnode interlock. 1757 */ 1758 vholdl(vp); 1759 mtx_unlock(&sync_mtx); 1760 VI_UNLOCK(vp); 1761 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 1762 vdrop(vp); 1763 mtx_lock(&sync_mtx); 1764 return (*bo == LIST_FIRST(slp)); 1765 } 1766 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1767 (void) VOP_FSYNC(vp, MNT_LAZY, td); 1768 VOP_UNLOCK(vp, 0); 1769 vn_finished_write(mp); 1770 BO_LOCK(*bo); 1771 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) { 1772 /* 1773 * Put us back on the worklist. The worklist 1774 * routine will remove us from our current 1775 * position and then add us back in at a later 1776 * position. 1777 */ 1778 vn_syncer_add_to_worklist(*bo, syncdelay); 1779 } 1780 BO_UNLOCK(*bo); 1781 vdrop(vp); 1782 mtx_lock(&sync_mtx); 1783 return (0); 1784 } 1785 1786 /* 1787 * System filesystem synchronizer daemon. 1788 */ 1789 static void 1790 sched_sync(void) 1791 { 1792 struct synclist *gnext, *next; 1793 struct synclist *gslp, *slp; 1794 struct bufobj *bo; 1795 long starttime; 1796 struct thread *td = curthread; 1797 int last_work_seen; 1798 int net_worklist_len; 1799 int syncer_final_iter; 1800 int first_printf; 1801 int error; 1802 1803 last_work_seen = 0; 1804 syncer_final_iter = 0; 1805 first_printf = 1; 1806 syncer_state = SYNCER_RUNNING; 1807 starttime = time_uptime; 1808 td->td_pflags |= TDP_NORUNNINGBUF; 1809 1810 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, 1811 SHUTDOWN_PRI_LAST); 1812 1813 mtx_lock(&sync_mtx); 1814 for (;;) { 1815 if (syncer_state == SYNCER_FINAL_DELAY && 1816 syncer_final_iter == 0) { 1817 mtx_unlock(&sync_mtx); 1818 kproc_suspend_check(td->td_proc); 1819 mtx_lock(&sync_mtx); 1820 } 1821 net_worklist_len = syncer_worklist_len - sync_vnode_count; 1822 if (syncer_state != SYNCER_RUNNING && 1823 starttime != time_uptime) { 1824 if (first_printf) { 1825 printf("\nSyncing disks, vnodes remaining..."); 1826 first_printf = 0; 1827 } 1828 printf("%d ", net_worklist_len); 1829 } 1830 starttime = time_uptime; 1831 1832 /* 1833 * Push files whose dirty time has expired. Be careful 1834 * of interrupt race on slp queue. 1835 * 1836 * Skip over empty worklist slots when shutting down. 1837 */ 1838 do { 1839 slp = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno]; 1840 gslp = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno]; 1841 syncer_delayno += 1; 1842 if (syncer_delayno == syncer_maxdelay) 1843 syncer_delayno = 0; 1844 next = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno]; 1845 gnext = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno]; 1846 /* 1847 * If the worklist has wrapped since the 1848 * it was emptied of all but syncer vnodes, 1849 * switch to the FINAL_DELAY state and run 1850 * for one more second. 1851 */ 1852 if (syncer_state == SYNCER_SHUTTING_DOWN && 1853 net_worklist_len == 0 && 1854 last_work_seen == syncer_delayno) { 1855 syncer_state = SYNCER_FINAL_DELAY; 1856 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; 1857 } 1858 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && 1859 LIST_EMPTY(gslp) && syncer_worklist_len > 0); 1860 1861 /* 1862 * Keep track of the last time there was anything 1863 * on the worklist other than syncer vnodes. 1864 * Return to the SHUTTING_DOWN state if any 1865 * new work appears. 1866 */ 1867 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) 1868 last_work_seen = syncer_delayno; 1869 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) 1870 syncer_state = SYNCER_SHUTTING_DOWN; 1871 while (!LIST_EMPTY(slp)) { 1872 error = sync_vnode(slp, &bo, td); 1873 if (error == 1) { 1874 LIST_REMOVE(bo, bo_synclist); 1875 LIST_INSERT_HEAD(next, bo, bo_synclist); 1876 continue; 1877 } 1878 #ifdef SW_WATCHDOG 1879 if (first_printf == 0) 1880 wdog_kern_pat(WD_LASTVAL); 1881 #endif 1882 } 1883 if (!LIST_EMPTY(gslp)) { 1884 mtx_unlock(&sync_mtx); 1885 mtx_lock(&Giant); 1886 mtx_lock(&sync_mtx); 1887 while (!LIST_EMPTY(gslp)) { 1888 error = sync_vnode(gslp, &bo, td); 1889 if (error == 1) { 1890 LIST_REMOVE(bo, bo_synclist); 1891 LIST_INSERT_HEAD(gnext, bo, 1892 bo_synclist); 1893 continue; 1894 } 1895 } 1896 mtx_unlock(&Giant); 1897 } 1898 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) 1899 syncer_final_iter--; 1900 /* 1901 * The variable rushjob allows the kernel to speed up the 1902 * processing of the filesystem syncer process. A rushjob 1903 * value of N tells the filesystem syncer to process the next 1904 * N seconds worth of work on its queue ASAP. Currently rushjob 1905 * is used by the soft update code to speed up the filesystem 1906 * syncer process when the incore state is getting so far 1907 * ahead of the disk that the kernel memory pool is being 1908 * threatened with exhaustion. 1909 */ 1910 if (rushjob > 0) { 1911 rushjob -= 1; 1912 continue; 1913 } 1914 /* 1915 * Just sleep for a short period of time between 1916 * iterations when shutting down to allow some I/O 1917 * to happen. 1918 * 1919 * If it has taken us less than a second to process the 1920 * current work, then wait. Otherwise start right over 1921 * again. We can still lose time if any single round 1922 * takes more than two seconds, but it does not really 1923 * matter as we are just trying to generally pace the 1924 * filesystem activity. 1925 */ 1926 if (syncer_state != SYNCER_RUNNING || 1927 time_uptime == starttime) { 1928 thread_lock(td); 1929 sched_prio(td, PPAUSE); 1930 thread_unlock(td); 1931 } 1932 if (syncer_state != SYNCER_RUNNING) 1933 cv_timedwait(&sync_wakeup, &sync_mtx, 1934 hz / SYNCER_SHUTDOWN_SPEEDUP); 1935 else if (time_uptime == starttime) 1936 cv_timedwait(&sync_wakeup, &sync_mtx, hz); 1937 } 1938 } 1939 1940 /* 1941 * Request the syncer daemon to speed up its work. 1942 * We never push it to speed up more than half of its 1943 * normal turn time, otherwise it could take over the cpu. 1944 */ 1945 int 1946 speedup_syncer(void) 1947 { 1948 int ret = 0; 1949 1950 mtx_lock(&sync_mtx); 1951 if (rushjob < syncdelay / 2) { 1952 rushjob += 1; 1953 stat_rush_requests += 1; 1954 ret = 1; 1955 } 1956 mtx_unlock(&sync_mtx); 1957 cv_broadcast(&sync_wakeup); 1958 return (ret); 1959 } 1960 1961 /* 1962 * Tell the syncer to speed up its work and run though its work 1963 * list several times, then tell it to shut down. 1964 */ 1965 static void 1966 syncer_shutdown(void *arg, int howto) 1967 { 1968 1969 if (howto & RB_NOSYNC) 1970 return; 1971 mtx_lock(&sync_mtx); 1972 syncer_state = SYNCER_SHUTTING_DOWN; 1973 rushjob = 0; 1974 mtx_unlock(&sync_mtx); 1975 cv_broadcast(&sync_wakeup); 1976 kproc_shutdown(arg, howto); 1977 } 1978 1979 /* 1980 * Reassign a buffer from one vnode to another. 1981 * Used to assign file specific control information 1982 * (indirect blocks) to the vnode to which they belong. 1983 */ 1984 void 1985 reassignbuf(struct buf *bp) 1986 { 1987 struct vnode *vp; 1988 struct bufobj *bo; 1989 int delay; 1990 #ifdef INVARIANTS 1991 struct bufv *bv; 1992 #endif 1993 1994 vp = bp->b_vp; 1995 bo = bp->b_bufobj; 1996 ++reassignbufcalls; 1997 1998 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", 1999 bp, bp->b_vp, bp->b_flags); 2000 /* 2001 * B_PAGING flagged buffers cannot be reassigned because their vp 2002 * is not fully linked in. 2003 */ 2004 if (bp->b_flags & B_PAGING) 2005 panic("cannot reassign paging buffer"); 2006 2007 /* 2008 * Delete from old vnode list, if on one. 2009 */ 2010 BO_LOCK(bo); 2011 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 2012 buf_vlist_remove(bp); 2013 else 2014 panic("reassignbuf: Buffer %p not on queue.", bp); 2015 /* 2016 * If dirty, put on list of dirty buffers; otherwise insert onto list 2017 * of clean buffers. 2018 */ 2019 if (bp->b_flags & B_DELWRI) { 2020 if ((bo->bo_flag & BO_ONWORKLST) == 0) { 2021 switch (vp->v_type) { 2022 case VDIR: 2023 delay = dirdelay; 2024 break; 2025 case VCHR: 2026 delay = metadelay; 2027 break; 2028 default: 2029 delay = filedelay; 2030 } 2031 vn_syncer_add_to_worklist(bo, delay); 2032 } 2033 buf_vlist_add(bp, bo, BX_VNDIRTY); 2034 } else { 2035 buf_vlist_add(bp, bo, BX_VNCLEAN); 2036 2037 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { 2038 mtx_lock(&sync_mtx); 2039 LIST_REMOVE(bo, bo_synclist); 2040 syncer_worklist_len--; 2041 mtx_unlock(&sync_mtx); 2042 bo->bo_flag &= ~BO_ONWORKLST; 2043 } 2044 } 2045 #ifdef INVARIANTS 2046 bv = &bo->bo_clean; 2047 bp = TAILQ_FIRST(&bv->bv_hd); 2048 KASSERT(bp == NULL || bp->b_bufobj == bo, 2049 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2050 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2051 KASSERT(bp == NULL || bp->b_bufobj == bo, 2052 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2053 bv = &bo->bo_dirty; 2054 bp = TAILQ_FIRST(&bv->bv_hd); 2055 KASSERT(bp == NULL || bp->b_bufobj == bo, 2056 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2057 bp = TAILQ_LAST(&bv->bv_hd, buflists); 2058 KASSERT(bp == NULL || bp->b_bufobj == bo, 2059 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); 2060 #endif 2061 BO_UNLOCK(bo); 2062 } 2063 2064 /* 2065 * Increment the use and hold counts on the vnode, taking care to reference 2066 * the driver's usecount if this is a chardev. The vholdl() will remove 2067 * the vnode from the free list if it is presently free. Requires the 2068 * vnode interlock and returns with it held. 2069 */ 2070 static void 2071 v_incr_usecount(struct vnode *vp) 2072 { 2073 2074 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2075 vp->v_usecount++; 2076 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2077 dev_lock(); 2078 vp->v_rdev->si_usecount++; 2079 dev_unlock(); 2080 } 2081 vholdl(vp); 2082 } 2083 2084 /* 2085 * Turn a holdcnt into a use+holdcnt such that only one call to 2086 * v_decr_usecount is needed. 2087 */ 2088 static void 2089 v_upgrade_usecount(struct vnode *vp) 2090 { 2091 2092 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2093 vp->v_usecount++; 2094 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2095 dev_lock(); 2096 vp->v_rdev->si_usecount++; 2097 dev_unlock(); 2098 } 2099 } 2100 2101 /* 2102 * Decrement the vnode use and hold count along with the driver's usecount 2103 * if this is a chardev. The vdropl() below releases the vnode interlock 2104 * as it may free the vnode. 2105 */ 2106 static void 2107 v_decr_usecount(struct vnode *vp) 2108 { 2109 2110 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2111 VNASSERT(vp->v_usecount > 0, vp, 2112 ("v_decr_usecount: negative usecount")); 2113 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2114 vp->v_usecount--; 2115 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2116 dev_lock(); 2117 vp->v_rdev->si_usecount--; 2118 dev_unlock(); 2119 } 2120 vdropl(vp); 2121 } 2122 2123 /* 2124 * Decrement only the use count and driver use count. This is intended to 2125 * be paired with a follow on vdropl() to release the remaining hold count. 2126 * In this way we may vgone() a vnode with a 0 usecount without risk of 2127 * having it end up on a free list because the hold count is kept above 0. 2128 */ 2129 static void 2130 v_decr_useonly(struct vnode *vp) 2131 { 2132 2133 ASSERT_VI_LOCKED(vp, __FUNCTION__); 2134 VNASSERT(vp->v_usecount > 0, vp, 2135 ("v_decr_useonly: negative usecount")); 2136 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2137 vp->v_usecount--; 2138 if (vp->v_type == VCHR && vp->v_rdev != NULL) { 2139 dev_lock(); 2140 vp->v_rdev->si_usecount--; 2141 dev_unlock(); 2142 } 2143 } 2144 2145 /* 2146 * Grab a particular vnode from the free list, increment its 2147 * reference count and lock it. VI_DOOMED is set if the vnode 2148 * is being destroyed. Only callers who specify LK_RETRY will 2149 * see doomed vnodes. If inactive processing was delayed in 2150 * vput try to do it here. 2151 */ 2152 int 2153 vget(struct vnode *vp, int flags, struct thread *td) 2154 { 2155 int error; 2156 2157 error = 0; 2158 VFS_ASSERT_GIANT(vp->v_mount); 2159 VNASSERT((flags & LK_TYPE_MASK) != 0, vp, 2160 ("vget: invalid lock operation")); 2161 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); 2162 2163 if ((flags & LK_INTERLOCK) == 0) 2164 VI_LOCK(vp); 2165 vholdl(vp); 2166 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) { 2167 vdrop(vp); 2168 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, 2169 vp); 2170 return (error); 2171 } 2172 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) 2173 panic("vget: vn_lock failed to return ENOENT\n"); 2174 VI_LOCK(vp); 2175 /* Upgrade our holdcnt to a usecount. */ 2176 v_upgrade_usecount(vp); 2177 /* 2178 * We don't guarantee that any particular close will 2179 * trigger inactive processing so just make a best effort 2180 * here at preventing a reference to a removed file. If 2181 * we don't succeed no harm is done. 2182 */ 2183 if (vp->v_iflag & VI_OWEINACT) { 2184 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE && 2185 (flags & LK_NOWAIT) == 0) 2186 vinactive(vp, td); 2187 vp->v_iflag &= ~VI_OWEINACT; 2188 } 2189 VI_UNLOCK(vp); 2190 return (0); 2191 } 2192 2193 /* 2194 * Increase the reference count of a vnode. 2195 */ 2196 void 2197 vref(struct vnode *vp) 2198 { 2199 2200 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2201 VI_LOCK(vp); 2202 v_incr_usecount(vp); 2203 VI_UNLOCK(vp); 2204 } 2205 2206 /* 2207 * Return reference count of a vnode. 2208 * 2209 * The results of this call are only guaranteed when some mechanism other 2210 * than the VI lock is used to stop other processes from gaining references 2211 * to the vnode. This may be the case if the caller holds the only reference. 2212 * This is also useful when stale data is acceptable as race conditions may 2213 * be accounted for by some other means. 2214 */ 2215 int 2216 vrefcnt(struct vnode *vp) 2217 { 2218 int usecnt; 2219 2220 VI_LOCK(vp); 2221 usecnt = vp->v_usecount; 2222 VI_UNLOCK(vp); 2223 2224 return (usecnt); 2225 } 2226 2227 #define VPUTX_VRELE 1 2228 #define VPUTX_VPUT 2 2229 #define VPUTX_VUNREF 3 2230 2231 static void 2232 vputx(struct vnode *vp, int func) 2233 { 2234 int error; 2235 2236 KASSERT(vp != NULL, ("vputx: null vp")); 2237 if (func == VPUTX_VUNREF) 2238 ASSERT_VOP_LOCKED(vp, "vunref"); 2239 else if (func == VPUTX_VPUT) 2240 ASSERT_VOP_LOCKED(vp, "vput"); 2241 else 2242 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); 2243 VFS_ASSERT_GIANT(vp->v_mount); 2244 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2245 VI_LOCK(vp); 2246 2247 /* Skip this v_writecount check if we're going to panic below. */ 2248 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, 2249 ("vputx: missed vn_close")); 2250 error = 0; 2251 2252 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && 2253 vp->v_usecount == 1)) { 2254 if (func == VPUTX_VPUT) 2255 VOP_UNLOCK(vp, 0); 2256 v_decr_usecount(vp); 2257 return; 2258 } 2259 2260 if (vp->v_usecount != 1) { 2261 vprint("vputx: negative ref count", vp); 2262 panic("vputx: negative ref cnt"); 2263 } 2264 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); 2265 /* 2266 * We want to hold the vnode until the inactive finishes to 2267 * prevent vgone() races. We drop the use count here and the 2268 * hold count below when we're done. 2269 */ 2270 v_decr_useonly(vp); 2271 /* 2272 * We must call VOP_INACTIVE with the node locked. Mark 2273 * as VI_DOINGINACT to avoid recursion. 2274 */ 2275 vp->v_iflag |= VI_OWEINACT; 2276 switch (func) { 2277 case VPUTX_VRELE: 2278 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); 2279 VI_LOCK(vp); 2280 break; 2281 case VPUTX_VPUT: 2282 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { 2283 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | 2284 LK_NOWAIT); 2285 VI_LOCK(vp); 2286 } 2287 break; 2288 case VPUTX_VUNREF: 2289 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 2290 error = EBUSY; 2291 break; 2292 } 2293 if (vp->v_usecount > 0) 2294 vp->v_iflag &= ~VI_OWEINACT; 2295 if (error == 0) { 2296 if (vp->v_iflag & VI_OWEINACT) 2297 vinactive(vp, curthread); 2298 if (func != VPUTX_VUNREF) 2299 VOP_UNLOCK(vp, 0); 2300 } 2301 vdropl(vp); 2302 } 2303 2304 /* 2305 * Vnode put/release. 2306 * If count drops to zero, call inactive routine and return to freelist. 2307 */ 2308 void 2309 vrele(struct vnode *vp) 2310 { 2311 2312 vputx(vp, VPUTX_VRELE); 2313 } 2314 2315 /* 2316 * Release an already locked vnode. This give the same effects as 2317 * unlock+vrele(), but takes less time and avoids releasing and 2318 * re-aquiring the lock (as vrele() acquires the lock internally.) 2319 */ 2320 void 2321 vput(struct vnode *vp) 2322 { 2323 2324 vputx(vp, VPUTX_VPUT); 2325 } 2326 2327 /* 2328 * Release an exclusively locked vnode. Do not unlock the vnode lock. 2329 */ 2330 void 2331 vunref(struct vnode *vp) 2332 { 2333 2334 vputx(vp, VPUTX_VUNREF); 2335 } 2336 2337 /* 2338 * Somebody doesn't want the vnode recycled. 2339 */ 2340 void 2341 vhold(struct vnode *vp) 2342 { 2343 2344 VI_LOCK(vp); 2345 vholdl(vp); 2346 VI_UNLOCK(vp); 2347 } 2348 2349 void 2350 vholdl(struct vnode *vp) 2351 { 2352 2353 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2354 vp->v_holdcnt++; 2355 if (VSHOULDBUSY(vp)) 2356 vbusy(vp); 2357 } 2358 2359 /* 2360 * Note that there is one less who cares about this vnode. vdrop() is the 2361 * opposite of vhold(). 2362 */ 2363 void 2364 vdrop(struct vnode *vp) 2365 { 2366 2367 VI_LOCK(vp); 2368 vdropl(vp); 2369 } 2370 2371 /* 2372 * Drop the hold count of the vnode. If this is the last reference to 2373 * the vnode we will free it if it has been vgone'd otherwise it is 2374 * placed on the free list. 2375 */ 2376 void 2377 vdropl(struct vnode *vp) 2378 { 2379 2380 ASSERT_VI_LOCKED(vp, "vdropl"); 2381 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2382 if (vp->v_holdcnt <= 0) 2383 panic("vdrop: holdcnt %d", vp->v_holdcnt); 2384 vp->v_holdcnt--; 2385 if (vp->v_holdcnt == 0) { 2386 if (vp->v_iflag & VI_DOOMED) { 2387 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, 2388 vp); 2389 vdestroy(vp); 2390 return; 2391 } else 2392 vfree(vp); 2393 } 2394 VI_UNLOCK(vp); 2395 } 2396 2397 /* 2398 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT 2399 * flags. DOINGINACT prevents us from recursing in calls to vinactive. 2400 * OWEINACT tracks whether a vnode missed a call to inactive due to a 2401 * failed lock upgrade. 2402 */ 2403 static void 2404 vinactive(struct vnode *vp, struct thread *td) 2405 { 2406 2407 ASSERT_VOP_ELOCKED(vp, "vinactive"); 2408 ASSERT_VI_LOCKED(vp, "vinactive"); 2409 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, 2410 ("vinactive: recursed on VI_DOINGINACT")); 2411 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2412 vp->v_iflag |= VI_DOINGINACT; 2413 vp->v_iflag &= ~VI_OWEINACT; 2414 VI_UNLOCK(vp); 2415 VOP_INACTIVE(vp, td); 2416 VI_LOCK(vp); 2417 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, 2418 ("vinactive: lost VI_DOINGINACT")); 2419 vp->v_iflag &= ~VI_DOINGINACT; 2420 } 2421 2422 /* 2423 * Remove any vnodes in the vnode table belonging to mount point mp. 2424 * 2425 * If FORCECLOSE is not specified, there should not be any active ones, 2426 * return error if any are found (nb: this is a user error, not a 2427 * system error). If FORCECLOSE is specified, detach any active vnodes 2428 * that are found. 2429 * 2430 * If WRITECLOSE is set, only flush out regular file vnodes open for 2431 * writing. 2432 * 2433 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. 2434 * 2435 * `rootrefs' specifies the base reference count for the root vnode 2436 * of this filesystem. The root vnode is considered busy if its 2437 * v_usecount exceeds this value. On a successful return, vflush(, td) 2438 * will call vrele() on the root vnode exactly rootrefs times. 2439 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 2440 * be zero. 2441 */ 2442 #ifdef DIAGNOSTIC 2443 static int busyprt = 0; /* print out busy vnodes */ 2444 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes"); 2445 #endif 2446 2447 int 2448 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) 2449 { 2450 struct vnode *vp, *mvp, *rootvp = NULL; 2451 struct vattr vattr; 2452 int busy = 0, error; 2453 2454 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, 2455 rootrefs, flags); 2456 if (rootrefs > 0) { 2457 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 2458 ("vflush: bad args")); 2459 /* 2460 * Get the filesystem root vnode. We can vput() it 2461 * immediately, since with rootrefs > 0, it won't go away. 2462 */ 2463 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) { 2464 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", 2465 __func__, error); 2466 return (error); 2467 } 2468 vput(rootvp); 2469 } 2470 MNT_ILOCK(mp); 2471 loop: 2472 MNT_VNODE_FOREACH(vp, mp, mvp) { 2473 VI_LOCK(vp); 2474 vholdl(vp); 2475 MNT_IUNLOCK(mp); 2476 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); 2477 if (error) { 2478 vdrop(vp); 2479 MNT_ILOCK(mp); 2480 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 2481 goto loop; 2482 } 2483 /* 2484 * Skip over a vnodes marked VV_SYSTEM. 2485 */ 2486 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { 2487 VOP_UNLOCK(vp, 0); 2488 vdrop(vp); 2489 MNT_ILOCK(mp); 2490 continue; 2491 } 2492 /* 2493 * If WRITECLOSE is set, flush out unlinked but still open 2494 * files (even if open only for reading) and regular file 2495 * vnodes open for writing. 2496 */ 2497 if (flags & WRITECLOSE) { 2498 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 2499 VI_LOCK(vp); 2500 2501 if ((vp->v_type == VNON || 2502 (error == 0 && vattr.va_nlink > 0)) && 2503 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2504 VOP_UNLOCK(vp, 0); 2505 vdropl(vp); 2506 MNT_ILOCK(mp); 2507 continue; 2508 } 2509 } else 2510 VI_LOCK(vp); 2511 /* 2512 * With v_usecount == 0, all we need to do is clear out the 2513 * vnode data structures and we are done. 2514 * 2515 * If FORCECLOSE is set, forcibly close the vnode. 2516 */ 2517 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { 2518 VNASSERT(vp->v_usecount == 0 || 2519 (vp->v_type != VCHR && vp->v_type != VBLK), vp, 2520 ("device VNODE %p is FORCECLOSED", vp)); 2521 vgonel(vp); 2522 } else { 2523 busy++; 2524 #ifdef DIAGNOSTIC 2525 if (busyprt) 2526 vprint("vflush: busy vnode", vp); 2527 #endif 2528 } 2529 VOP_UNLOCK(vp, 0); 2530 vdropl(vp); 2531 MNT_ILOCK(mp); 2532 } 2533 MNT_IUNLOCK(mp); 2534 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2535 /* 2536 * If just the root vnode is busy, and if its refcount 2537 * is equal to `rootrefs', then go ahead and kill it. 2538 */ 2539 VI_LOCK(rootvp); 2540 KASSERT(busy > 0, ("vflush: not busy")); 2541 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, 2542 ("vflush: usecount %d < rootrefs %d", 2543 rootvp->v_usecount, rootrefs)); 2544 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2545 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK); 2546 vgone(rootvp); 2547 VOP_UNLOCK(rootvp, 0); 2548 busy = 0; 2549 } else 2550 VI_UNLOCK(rootvp); 2551 } 2552 if (busy) { 2553 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, 2554 busy); 2555 return (EBUSY); 2556 } 2557 for (; rootrefs > 0; rootrefs--) 2558 vrele(rootvp); 2559 return (0); 2560 } 2561 2562 /* 2563 * Recycle an unused vnode to the front of the free list. 2564 */ 2565 int 2566 vrecycle(struct vnode *vp, struct thread *td) 2567 { 2568 int recycled; 2569 2570 ASSERT_VOP_ELOCKED(vp, "vrecycle"); 2571 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2572 recycled = 0; 2573 VI_LOCK(vp); 2574 if (vp->v_usecount == 0) { 2575 recycled = 1; 2576 vgonel(vp); 2577 } 2578 VI_UNLOCK(vp); 2579 return (recycled); 2580 } 2581 2582 /* 2583 * Eliminate all activity associated with a vnode 2584 * in preparation for reuse. 2585 */ 2586 void 2587 vgone(struct vnode *vp) 2588 { 2589 VI_LOCK(vp); 2590 vgonel(vp); 2591 VI_UNLOCK(vp); 2592 } 2593 2594 /* 2595 * vgone, with the vp interlock held. 2596 */ 2597 void 2598 vgonel(struct vnode *vp) 2599 { 2600 struct thread *td; 2601 int oweinact; 2602 int active; 2603 struct mount *mp; 2604 2605 ASSERT_VOP_ELOCKED(vp, "vgonel"); 2606 ASSERT_VI_LOCKED(vp, "vgonel"); 2607 VNASSERT(vp->v_holdcnt, vp, 2608 ("vgonel: vp %p has no reference.", vp)); 2609 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 2610 td = curthread; 2611 2612 /* 2613 * Don't vgonel if we're already doomed. 2614 */ 2615 if (vp->v_iflag & VI_DOOMED) 2616 return; 2617 vp->v_iflag |= VI_DOOMED; 2618 /* 2619 * Check to see if the vnode is in use. If so, we have to call 2620 * VOP_CLOSE() and VOP_INACTIVE(). 2621 */ 2622 active = vp->v_usecount; 2623 oweinact = (vp->v_iflag & VI_OWEINACT); 2624 VI_UNLOCK(vp); 2625 /* 2626 * Clean out any buffers associated with the vnode. 2627 * If the flush fails, just toss the buffers. 2628 */ 2629 mp = NULL; 2630 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) 2631 (void) vn_start_secondary_write(vp, &mp, V_WAIT); 2632 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) 2633 vinvalbuf(vp, 0, 0, 0); 2634 2635 /* 2636 * If purging an active vnode, it must be closed and 2637 * deactivated before being reclaimed. 2638 */ 2639 if (active) 2640 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2641 if (oweinact || active) { 2642 VI_LOCK(vp); 2643 if ((vp->v_iflag & VI_DOINGINACT) == 0) 2644 vinactive(vp, td); 2645 VI_UNLOCK(vp); 2646 } 2647 /* 2648 * Reclaim the vnode. 2649 */ 2650 if (VOP_RECLAIM(vp, td)) 2651 panic("vgone: cannot reclaim"); 2652 if (mp != NULL) 2653 vn_finished_secondary_write(mp); 2654 VNASSERT(vp->v_object == NULL, vp, 2655 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); 2656 /* 2657 * Clear the advisory locks and wake up waiting threads. 2658 */ 2659 (void)VOP_ADVLOCKPURGE(vp); 2660 /* 2661 * Delete from old mount point vnode list. 2662 */ 2663 delmntque(vp); 2664 cache_purge(vp); 2665 /* 2666 * Done with purge, reset to the standard lock and invalidate 2667 * the vnode. 2668 */ 2669 VI_LOCK(vp); 2670 vp->v_vnlock = &vp->v_lock; 2671 vp->v_op = &dead_vnodeops; 2672 vp->v_tag = "none"; 2673 vp->v_type = VBAD; 2674 } 2675 2676 /* 2677 * Calculate the total number of references to a special device. 2678 */ 2679 int 2680 vcount(struct vnode *vp) 2681 { 2682 int count; 2683 2684 dev_lock(); 2685 count = vp->v_rdev->si_usecount; 2686 dev_unlock(); 2687 return (count); 2688 } 2689 2690 /* 2691 * Same as above, but using the struct cdev *as argument 2692 */ 2693 int 2694 count_dev(struct cdev *dev) 2695 { 2696 int count; 2697 2698 dev_lock(); 2699 count = dev->si_usecount; 2700 dev_unlock(); 2701 return(count); 2702 } 2703 2704 /* 2705 * Print out a description of a vnode. 2706 */ 2707 static char *typename[] = 2708 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD", 2709 "VMARKER"}; 2710 2711 void 2712 vn_printf(struct vnode *vp, const char *fmt, ...) 2713 { 2714 va_list ap; 2715 char buf[256], buf2[16]; 2716 u_long flags; 2717 2718 va_start(ap, fmt); 2719 vprintf(fmt, ap); 2720 va_end(ap); 2721 printf("%p: ", (void *)vp); 2722 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); 2723 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", 2724 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); 2725 buf[0] = '\0'; 2726 buf[1] = '\0'; 2727 if (vp->v_vflag & VV_ROOT) 2728 strlcat(buf, "|VV_ROOT", sizeof(buf)); 2729 if (vp->v_vflag & VV_ISTTY) 2730 strlcat(buf, "|VV_ISTTY", sizeof(buf)); 2731 if (vp->v_vflag & VV_NOSYNC) 2732 strlcat(buf, "|VV_NOSYNC", sizeof(buf)); 2733 if (vp->v_vflag & VV_CACHEDLABEL) 2734 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); 2735 if (vp->v_vflag & VV_TEXT) 2736 strlcat(buf, "|VV_TEXT", sizeof(buf)); 2737 if (vp->v_vflag & VV_COPYONWRITE) 2738 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); 2739 if (vp->v_vflag & VV_SYSTEM) 2740 strlcat(buf, "|VV_SYSTEM", sizeof(buf)); 2741 if (vp->v_vflag & VV_PROCDEP) 2742 strlcat(buf, "|VV_PROCDEP", sizeof(buf)); 2743 if (vp->v_vflag & VV_NOKNOTE) 2744 strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); 2745 if (vp->v_vflag & VV_DELETED) 2746 strlcat(buf, "|VV_DELETED", sizeof(buf)); 2747 if (vp->v_vflag & VV_MD) 2748 strlcat(buf, "|VV_MD", sizeof(buf)); 2749 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | 2750 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | 2751 VV_NOKNOTE | VV_DELETED | VV_MD); 2752 if (flags != 0) { 2753 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); 2754 strlcat(buf, buf2, sizeof(buf)); 2755 } 2756 if (vp->v_iflag & VI_MOUNT) 2757 strlcat(buf, "|VI_MOUNT", sizeof(buf)); 2758 if (vp->v_iflag & VI_AGE) 2759 strlcat(buf, "|VI_AGE", sizeof(buf)); 2760 if (vp->v_iflag & VI_DOOMED) 2761 strlcat(buf, "|VI_DOOMED", sizeof(buf)); 2762 if (vp->v_iflag & VI_FREE) 2763 strlcat(buf, "|VI_FREE", sizeof(buf)); 2764 if (vp->v_iflag & VI_DOINGINACT) 2765 strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); 2766 if (vp->v_iflag & VI_OWEINACT) 2767 strlcat(buf, "|VI_OWEINACT", sizeof(buf)); 2768 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE | 2769 VI_DOINGINACT | VI_OWEINACT); 2770 if (flags != 0) { 2771 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); 2772 strlcat(buf, buf2, sizeof(buf)); 2773 } 2774 printf(" flags (%s)\n", buf + 1); 2775 if (mtx_owned(VI_MTX(vp))) 2776 printf(" VI_LOCKed"); 2777 if (vp->v_object != NULL) 2778 printf(" v_object %p ref %d pages %d\n", 2779 vp->v_object, vp->v_object->ref_count, 2780 vp->v_object->resident_page_count); 2781 printf(" "); 2782 lockmgr_printinfo(vp->v_vnlock); 2783 if (vp->v_data != NULL) 2784 VOP_PRINT(vp); 2785 } 2786 2787 #ifdef DDB 2788 /* 2789 * List all of the locked vnodes in the system. 2790 * Called when debugging the kernel. 2791 */ 2792 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2793 { 2794 struct mount *mp, *nmp; 2795 struct vnode *vp; 2796 2797 /* 2798 * Note: because this is DDB, we can't obey the locking semantics 2799 * for these structures, which means we could catch an inconsistent 2800 * state and dereference a nasty pointer. Not much to be done 2801 * about that. 2802 */ 2803 db_printf("Locked vnodes\n"); 2804 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2805 nmp = TAILQ_NEXT(mp, mnt_list); 2806 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2807 if (vp->v_type != VMARKER && 2808 VOP_ISLOCKED(vp)) 2809 vprint("", vp); 2810 } 2811 nmp = TAILQ_NEXT(mp, mnt_list); 2812 } 2813 } 2814 2815 /* 2816 * Show details about the given vnode. 2817 */ 2818 DB_SHOW_COMMAND(vnode, db_show_vnode) 2819 { 2820 struct vnode *vp; 2821 2822 if (!have_addr) 2823 return; 2824 vp = (struct vnode *)addr; 2825 vn_printf(vp, "vnode "); 2826 } 2827 2828 /* 2829 * Show details about the given mount point. 2830 */ 2831 DB_SHOW_COMMAND(mount, db_show_mount) 2832 { 2833 struct mount *mp; 2834 struct vfsopt *opt; 2835 struct statfs *sp; 2836 struct vnode *vp; 2837 char buf[512]; 2838 u_int flags; 2839 2840 if (!have_addr) { 2841 /* No address given, print short info about all mount points. */ 2842 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 2843 db_printf("%p %s on %s (%s)\n", mp, 2844 mp->mnt_stat.f_mntfromname, 2845 mp->mnt_stat.f_mntonname, 2846 mp->mnt_stat.f_fstypename); 2847 if (db_pager_quit) 2848 break; 2849 } 2850 db_printf("\nMore info: show mount <addr>\n"); 2851 return; 2852 } 2853 2854 mp = (struct mount *)addr; 2855 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, 2856 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); 2857 2858 buf[0] = '\0'; 2859 flags = mp->mnt_flag; 2860 #define MNT_FLAG(flag) do { \ 2861 if (flags & (flag)) { \ 2862 if (buf[0] != '\0') \ 2863 strlcat(buf, ", ", sizeof(buf)); \ 2864 strlcat(buf, (#flag) + 4, sizeof(buf)); \ 2865 flags &= ~(flag); \ 2866 } \ 2867 } while (0) 2868 MNT_FLAG(MNT_RDONLY); 2869 MNT_FLAG(MNT_SYNCHRONOUS); 2870 MNT_FLAG(MNT_NOEXEC); 2871 MNT_FLAG(MNT_NOSUID); 2872 MNT_FLAG(MNT_UNION); 2873 MNT_FLAG(MNT_ASYNC); 2874 MNT_FLAG(MNT_SUIDDIR); 2875 MNT_FLAG(MNT_SOFTDEP); 2876 MNT_FLAG(MNT_SUJ); 2877 MNT_FLAG(MNT_NOSYMFOLLOW); 2878 MNT_FLAG(MNT_GJOURNAL); 2879 MNT_FLAG(MNT_MULTILABEL); 2880 MNT_FLAG(MNT_ACLS); 2881 MNT_FLAG(MNT_NOATIME); 2882 MNT_FLAG(MNT_NOCLUSTERR); 2883 MNT_FLAG(MNT_NOCLUSTERW); 2884 MNT_FLAG(MNT_NFS4ACLS); 2885 MNT_FLAG(MNT_EXRDONLY); 2886 MNT_FLAG(MNT_EXPORTED); 2887 MNT_FLAG(MNT_DEFEXPORTED); 2888 MNT_FLAG(MNT_EXPORTANON); 2889 MNT_FLAG(MNT_EXKERB); 2890 MNT_FLAG(MNT_EXPUBLIC); 2891 MNT_FLAG(MNT_LOCAL); 2892 MNT_FLAG(MNT_QUOTA); 2893 MNT_FLAG(MNT_ROOTFS); 2894 MNT_FLAG(MNT_USER); 2895 MNT_FLAG(MNT_IGNORE); 2896 MNT_FLAG(MNT_UPDATE); 2897 MNT_FLAG(MNT_DELEXPORT); 2898 MNT_FLAG(MNT_RELOAD); 2899 MNT_FLAG(MNT_FORCE); 2900 MNT_FLAG(MNT_SNAPSHOT); 2901 MNT_FLAG(MNT_BYFSID); 2902 #undef MNT_FLAG 2903 if (flags != 0) { 2904 if (buf[0] != '\0') 2905 strlcat(buf, ", ", sizeof(buf)); 2906 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 2907 "0x%08x", flags); 2908 } 2909 db_printf(" mnt_flag = %s\n", buf); 2910 2911 buf[0] = '\0'; 2912 flags = mp->mnt_kern_flag; 2913 #define MNT_KERN_FLAG(flag) do { \ 2914 if (flags & (flag)) { \ 2915 if (buf[0] != '\0') \ 2916 strlcat(buf, ", ", sizeof(buf)); \ 2917 strlcat(buf, (#flag) + 5, sizeof(buf)); \ 2918 flags &= ~(flag); \ 2919 } \ 2920 } while (0) 2921 MNT_KERN_FLAG(MNTK_UNMOUNTF); 2922 MNT_KERN_FLAG(MNTK_ASYNC); 2923 MNT_KERN_FLAG(MNTK_SOFTDEP); 2924 MNT_KERN_FLAG(MNTK_NOINSMNTQ); 2925 MNT_KERN_FLAG(MNTK_DRAINING); 2926 MNT_KERN_FLAG(MNTK_REFEXPIRE); 2927 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); 2928 MNT_KERN_FLAG(MNTK_SHARED_WRITES); 2929 MNT_KERN_FLAG(MNTK_UNMOUNT); 2930 MNT_KERN_FLAG(MNTK_MWAIT); 2931 MNT_KERN_FLAG(MNTK_SUSPEND); 2932 MNT_KERN_FLAG(MNTK_SUSPEND2); 2933 MNT_KERN_FLAG(MNTK_SUSPENDED); 2934 MNT_KERN_FLAG(MNTK_MPSAFE); 2935 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); 2936 MNT_KERN_FLAG(MNTK_NOKNOTE); 2937 #undef MNT_KERN_FLAG 2938 if (flags != 0) { 2939 if (buf[0] != '\0') 2940 strlcat(buf, ", ", sizeof(buf)); 2941 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), 2942 "0x%08x", flags); 2943 } 2944 db_printf(" mnt_kern_flag = %s\n", buf); 2945 2946 db_printf(" mnt_opt = "); 2947 opt = TAILQ_FIRST(mp->mnt_opt); 2948 if (opt != NULL) { 2949 db_printf("%s", opt->name); 2950 opt = TAILQ_NEXT(opt, link); 2951 while (opt != NULL) { 2952 db_printf(", %s", opt->name); 2953 opt = TAILQ_NEXT(opt, link); 2954 } 2955 } 2956 db_printf("\n"); 2957 2958 sp = &mp->mnt_stat; 2959 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " 2960 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " 2961 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " 2962 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", 2963 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, 2964 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, 2965 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, 2966 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, 2967 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, 2968 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, 2969 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, 2970 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); 2971 2972 db_printf(" mnt_cred = { uid=%u ruid=%u", 2973 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); 2974 if (jailed(mp->mnt_cred)) 2975 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); 2976 db_printf(" }\n"); 2977 db_printf(" mnt_ref = %d\n", mp->mnt_ref); 2978 db_printf(" mnt_gen = %d\n", mp->mnt_gen); 2979 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); 2980 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); 2981 db_printf(" mnt_noasync = %u\n", mp->mnt_noasync); 2982 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); 2983 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); 2984 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); 2985 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); 2986 db_printf(" mnt_secondary_accwrites = %d\n", 2987 mp->mnt_secondary_accwrites); 2988 db_printf(" mnt_gjprovider = %s\n", 2989 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); 2990 db_printf("\n"); 2991 2992 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2993 if (vp->v_type != VMARKER) { 2994 vn_printf(vp, "vnode "); 2995 if (db_pager_quit) 2996 break; 2997 } 2998 } 2999 } 3000 #endif /* DDB */ 3001 3002 /* 3003 * Fill in a struct xvfsconf based on a struct vfsconf. 3004 */ 3005 static void 3006 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) 3007 { 3008 3009 strcpy(xvfsp->vfc_name, vfsp->vfc_name); 3010 xvfsp->vfc_typenum = vfsp->vfc_typenum; 3011 xvfsp->vfc_refcount = vfsp->vfc_refcount; 3012 xvfsp->vfc_flags = vfsp->vfc_flags; 3013 /* 3014 * These are unused in userland, we keep them 3015 * to not break binary compatibility. 3016 */ 3017 xvfsp->vfc_vfsops = NULL; 3018 xvfsp->vfc_next = NULL; 3019 } 3020 3021 /* 3022 * Top level filesystem related information gathering. 3023 */ 3024 static int 3025 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) 3026 { 3027 struct vfsconf *vfsp; 3028 struct xvfsconf xvfsp; 3029 int error; 3030 3031 error = 0; 3032 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3033 bzero(&xvfsp, sizeof(xvfsp)); 3034 vfsconf2x(vfsp, &xvfsp); 3035 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); 3036 if (error) 3037 break; 3038 } 3039 return (error); 3040 } 3041 3042 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD, 3043 NULL, 0, sysctl_vfs_conflist, 3044 "S,xvfsconf", "List of all configured filesystems"); 3045 3046 #ifndef BURN_BRIDGES 3047 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 3048 3049 static int 3050 vfs_sysctl(SYSCTL_HANDLER_ARGS) 3051 { 3052 int *name = (int *)arg1 - 1; /* XXX */ 3053 u_int namelen = arg2 + 1; /* XXX */ 3054 struct vfsconf *vfsp; 3055 struct xvfsconf xvfsp; 3056 3057 log(LOG_WARNING, "userland calling deprecated sysctl, " 3058 "please rebuild world\n"); 3059 3060 #if 1 || defined(COMPAT_PRELITE2) 3061 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 3062 if (namelen == 1) 3063 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 3064 #endif 3065 3066 switch (name[1]) { 3067 case VFS_MAXTYPENUM: 3068 if (namelen != 2) 3069 return (ENOTDIR); 3070 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 3071 case VFS_CONF: 3072 if (namelen != 3) 3073 return (ENOTDIR); /* overloaded */ 3074 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) 3075 if (vfsp->vfc_typenum == name[2]) 3076 break; 3077 if (vfsp == NULL) 3078 return (EOPNOTSUPP); 3079 bzero(&xvfsp, sizeof(xvfsp)); 3080 vfsconf2x(vfsp, &xvfsp); 3081 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); 3082 } 3083 return (EOPNOTSUPP); 3084 } 3085 3086 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 3087 vfs_sysctl, "Generic filesystem"); 3088 3089 #if 1 || defined(COMPAT_PRELITE2) 3090 3091 static int 3092 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 3093 { 3094 int error; 3095 struct vfsconf *vfsp; 3096 struct ovfsconf ovfs; 3097 3098 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { 3099 bzero(&ovfs, sizeof(ovfs)); 3100 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 3101 strcpy(ovfs.vfc_name, vfsp->vfc_name); 3102 ovfs.vfc_index = vfsp->vfc_typenum; 3103 ovfs.vfc_refcount = vfsp->vfc_refcount; 3104 ovfs.vfc_flags = vfsp->vfc_flags; 3105 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 3106 if (error) 3107 return error; 3108 } 3109 return 0; 3110 } 3111 3112 #endif /* 1 || COMPAT_PRELITE2 */ 3113 #endif /* !BURN_BRIDGES */ 3114 3115 #define KINFO_VNODESLOP 10 3116 #ifdef notyet 3117 /* 3118 * Dump vnode list (via sysctl). 3119 */ 3120 /* ARGSUSED */ 3121 static int 3122 sysctl_vnode(SYSCTL_HANDLER_ARGS) 3123 { 3124 struct xvnode *xvn; 3125 struct mount *mp; 3126 struct vnode *vp; 3127 int error, len, n; 3128 3129 /* 3130 * Stale numvnodes access is not fatal here. 3131 */ 3132 req->lock = 0; 3133 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; 3134 if (!req->oldptr) 3135 /* Make an estimate */ 3136 return (SYSCTL_OUT(req, 0, len)); 3137 3138 error = sysctl_wire_old_buffer(req, 0); 3139 if (error != 0) 3140 return (error); 3141 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); 3142 n = 0; 3143 mtx_lock(&mountlist_mtx); 3144 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 3145 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) 3146 continue; 3147 MNT_ILOCK(mp); 3148 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 3149 if (n == len) 3150 break; 3151 vref(vp); 3152 xvn[n].xv_size = sizeof *xvn; 3153 xvn[n].xv_vnode = vp; 3154 xvn[n].xv_id = 0; /* XXX compat */ 3155 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field 3156 XV_COPY(usecount); 3157 XV_COPY(writecount); 3158 XV_COPY(holdcnt); 3159 XV_COPY(mount); 3160 XV_COPY(numoutput); 3161 XV_COPY(type); 3162 #undef XV_COPY 3163 xvn[n].xv_flag = vp->v_vflag; 3164 3165 switch (vp->v_type) { 3166 case VREG: 3167 case VDIR: 3168 case VLNK: 3169 break; 3170 case VBLK: 3171 case VCHR: 3172 if (vp->v_rdev == NULL) { 3173 vrele(vp); 3174 continue; 3175 } 3176 xvn[n].xv_dev = dev2udev(vp->v_rdev); 3177 break; 3178 case VSOCK: 3179 xvn[n].xv_socket = vp->v_socket; 3180 break; 3181 case VFIFO: 3182 xvn[n].xv_fifo = vp->v_fifoinfo; 3183 break; 3184 case VNON: 3185 case VBAD: 3186 default: 3187 /* shouldn't happen? */ 3188 vrele(vp); 3189 continue; 3190 } 3191 vrele(vp); 3192 ++n; 3193 } 3194 MNT_IUNLOCK(mp); 3195 mtx_lock(&mountlist_mtx); 3196 vfs_unbusy(mp); 3197 if (n == len) 3198 break; 3199 } 3200 mtx_unlock(&mountlist_mtx); 3201 3202 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); 3203 free(xvn, M_TEMP); 3204 return (error); 3205 } 3206 3207 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 3208 0, 0, sysctl_vnode, "S,xvnode", ""); 3209 #endif 3210 3211 /* 3212 * Unmount all filesystems. The list is traversed in reverse order 3213 * of mounting to avoid dependencies. 3214 */ 3215 void 3216 vfs_unmountall(void) 3217 { 3218 struct mount *mp; 3219 struct thread *td; 3220 int error; 3221 3222 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); 3223 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); 3224 td = curthread; 3225 3226 /* 3227 * Since this only runs when rebooting, it is not interlocked. 3228 */ 3229 while(!TAILQ_EMPTY(&mountlist)) { 3230 mp = TAILQ_LAST(&mountlist, mntlist); 3231 error = dounmount(mp, MNT_FORCE, td); 3232 if (error) { 3233 TAILQ_REMOVE(&mountlist, mp, mnt_list); 3234 /* 3235 * XXX: Due to the way in which we mount the root 3236 * file system off of devfs, devfs will generate a 3237 * "busy" warning when we try to unmount it before 3238 * the root. Don't print a warning as a result in 3239 * order to avoid false positive errors that may 3240 * cause needless upset. 3241 */ 3242 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 3243 printf("unmount of %s failed (", 3244 mp->mnt_stat.f_mntonname); 3245 if (error == EBUSY) 3246 printf("BUSY)\n"); 3247 else 3248 printf("%d)\n", error); 3249 } 3250 } else { 3251 /* The unmount has removed mp from the mountlist */ 3252 } 3253 } 3254 } 3255 3256 /* 3257 * perform msync on all vnodes under a mount point 3258 * the mount point must be locked. 3259 */ 3260 void 3261 vfs_msync(struct mount *mp, int flags) 3262 { 3263 struct vnode *vp, *mvp; 3264 struct vm_object *obj; 3265 3266 CTR2(KTR_VFS, "%s: mp %p", __func__, mp); 3267 MNT_ILOCK(mp); 3268 MNT_VNODE_FOREACH(vp, mp, mvp) { 3269 VI_LOCK(vp); 3270 obj = vp->v_object; 3271 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && 3272 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { 3273 MNT_IUNLOCK(mp); 3274 if (!vget(vp, 3275 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, 3276 curthread)) { 3277 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ 3278 vput(vp); 3279 MNT_ILOCK(mp); 3280 continue; 3281 } 3282 3283 obj = vp->v_object; 3284 if (obj != NULL) { 3285 VM_OBJECT_LOCK(obj); 3286 vm_object_page_clean(obj, 0, 0, 3287 flags == MNT_WAIT ? 3288 OBJPC_SYNC : OBJPC_NOSYNC); 3289 VM_OBJECT_UNLOCK(obj); 3290 } 3291 vput(vp); 3292 } 3293 MNT_ILOCK(mp); 3294 } else 3295 VI_UNLOCK(vp); 3296 } 3297 MNT_IUNLOCK(mp); 3298 } 3299 3300 /* 3301 * Mark a vnode as free, putting it up for recycling. 3302 */ 3303 static void 3304 vfree(struct vnode *vp) 3305 { 3306 3307 ASSERT_VI_LOCKED(vp, "vfree"); 3308 mtx_lock(&vnode_free_list_mtx); 3309 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); 3310 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); 3311 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); 3312 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, 3313 ("vfree: Freeing doomed vnode")); 3314 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3315 if (vp->v_iflag & VI_AGE) { 3316 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 3317 } else { 3318 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 3319 } 3320 freevnodes++; 3321 vp->v_iflag &= ~VI_AGE; 3322 vp->v_iflag |= VI_FREE; 3323 mtx_unlock(&vnode_free_list_mtx); 3324 } 3325 3326 /* 3327 * Opposite of vfree() - mark a vnode as in use. 3328 */ 3329 static void 3330 vbusy(struct vnode *vp) 3331 { 3332 ASSERT_VI_LOCKED(vp, "vbusy"); 3333 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); 3334 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); 3335 CTR2(KTR_VFS, "%s: vp %p", __func__, vp); 3336 3337 mtx_lock(&vnode_free_list_mtx); 3338 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 3339 freevnodes--; 3340 vp->v_iflag &= ~(VI_FREE|VI_AGE); 3341 mtx_unlock(&vnode_free_list_mtx); 3342 } 3343 3344 static void 3345 destroy_vpollinfo(struct vpollinfo *vi) 3346 { 3347 seldrain(&vi->vpi_selinfo); 3348 knlist_destroy(&vi->vpi_selinfo.si_note); 3349 mtx_destroy(&vi->vpi_lock); 3350 uma_zfree(vnodepoll_zone, vi); 3351 } 3352 3353 /* 3354 * Initalize per-vnode helper structure to hold poll-related state. 3355 */ 3356 void 3357 v_addpollinfo(struct vnode *vp) 3358 { 3359 struct vpollinfo *vi; 3360 3361 if (vp->v_pollinfo != NULL) 3362 return; 3363 vi = uma_zalloc(vnodepoll_zone, M_WAITOK); 3364 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 3365 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, 3366 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); 3367 VI_LOCK(vp); 3368 if (vp->v_pollinfo != NULL) { 3369 VI_UNLOCK(vp); 3370 destroy_vpollinfo(vi); 3371 return; 3372 } 3373 vp->v_pollinfo = vi; 3374 VI_UNLOCK(vp); 3375 } 3376 3377 /* 3378 * Record a process's interest in events which might happen to 3379 * a vnode. Because poll uses the historic select-style interface 3380 * internally, this routine serves as both the ``check for any 3381 * pending events'' and the ``record my interest in future events'' 3382 * functions. (These are done together, while the lock is held, 3383 * to avoid race conditions.) 3384 */ 3385 int 3386 vn_pollrecord(struct vnode *vp, struct thread *td, int events) 3387 { 3388 3389 v_addpollinfo(vp); 3390 mtx_lock(&vp->v_pollinfo->vpi_lock); 3391 if (vp->v_pollinfo->vpi_revents & events) { 3392 /* 3393 * This leaves events we are not interested 3394 * in available for the other process which 3395 * which presumably had requested them 3396 * (otherwise they would never have been 3397 * recorded). 3398 */ 3399 events &= vp->v_pollinfo->vpi_revents; 3400 vp->v_pollinfo->vpi_revents &= ~events; 3401 3402 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3403 return (events); 3404 } 3405 vp->v_pollinfo->vpi_events |= events; 3406 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 3407 mtx_unlock(&vp->v_pollinfo->vpi_lock); 3408 return (0); 3409 } 3410 3411 /* 3412 * Routine to create and manage a filesystem syncer vnode. 3413 */ 3414 #define sync_close ((int (*)(struct vop_close_args *))nullop) 3415 static int sync_fsync(struct vop_fsync_args *); 3416 static int sync_inactive(struct vop_inactive_args *); 3417 static int sync_reclaim(struct vop_reclaim_args *); 3418 3419 static struct vop_vector sync_vnodeops = { 3420 .vop_bypass = VOP_EOPNOTSUPP, 3421 .vop_close = sync_close, /* close */ 3422 .vop_fsync = sync_fsync, /* fsync */ 3423 .vop_inactive = sync_inactive, /* inactive */ 3424 .vop_reclaim = sync_reclaim, /* reclaim */ 3425 .vop_lock1 = vop_stdlock, /* lock */ 3426 .vop_unlock = vop_stdunlock, /* unlock */ 3427 .vop_islocked = vop_stdislocked, /* islocked */ 3428 }; 3429 3430 /* 3431 * Create a new filesystem syncer vnode for the specified mount point. 3432 */ 3433 void 3434 vfs_allocate_syncvnode(struct mount *mp) 3435 { 3436 struct vnode *vp; 3437 struct bufobj *bo; 3438 static long start, incr, next; 3439 int error; 3440 3441 /* Allocate a new vnode */ 3442 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); 3443 if (error != 0) 3444 panic("vfs_allocate_syncvnode: getnewvnode() failed"); 3445 vp->v_type = VNON; 3446 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3447 vp->v_vflag |= VV_FORCEINSMQ; 3448 error = insmntque(vp, mp); 3449 if (error != 0) 3450 panic("vfs_allocate_syncvnode: insmntque() failed"); 3451 vp->v_vflag &= ~VV_FORCEINSMQ; 3452 VOP_UNLOCK(vp, 0); 3453 /* 3454 * Place the vnode onto the syncer worklist. We attempt to 3455 * scatter them about on the list so that they will go off 3456 * at evenly distributed times even if all the filesystems 3457 * are mounted at once. 3458 */ 3459 next += incr; 3460 if (next == 0 || next > syncer_maxdelay) { 3461 start /= 2; 3462 incr /= 2; 3463 if (start == 0) { 3464 start = syncer_maxdelay / 2; 3465 incr = syncer_maxdelay; 3466 } 3467 next = start; 3468 } 3469 bo = &vp->v_bufobj; 3470 BO_LOCK(bo); 3471 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); 3472 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ 3473 mtx_lock(&sync_mtx); 3474 sync_vnode_count++; 3475 if (mp->mnt_syncer == NULL) { 3476 mp->mnt_syncer = vp; 3477 vp = NULL; 3478 } 3479 mtx_unlock(&sync_mtx); 3480 BO_UNLOCK(bo); 3481 if (vp != NULL) { 3482 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3483 vgone(vp); 3484 vput(vp); 3485 } 3486 } 3487 3488 void 3489 vfs_deallocate_syncvnode(struct mount *mp) 3490 { 3491 struct vnode *vp; 3492 3493 mtx_lock(&sync_mtx); 3494 vp = mp->mnt_syncer; 3495 if (vp != NULL) 3496 mp->mnt_syncer = NULL; 3497 mtx_unlock(&sync_mtx); 3498 if (vp != NULL) 3499 vrele(vp); 3500 } 3501 3502 /* 3503 * Do a lazy sync of the filesystem. 3504 */ 3505 static int 3506 sync_fsync(struct vop_fsync_args *ap) 3507 { 3508 struct vnode *syncvp = ap->a_vp; 3509 struct mount *mp = syncvp->v_mount; 3510 int error; 3511 struct bufobj *bo; 3512 3513 /* 3514 * We only need to do something if this is a lazy evaluation. 3515 */ 3516 if (ap->a_waitfor != MNT_LAZY) 3517 return (0); 3518 3519 /* 3520 * Move ourselves to the back of the sync list. 3521 */ 3522 bo = &syncvp->v_bufobj; 3523 BO_LOCK(bo); 3524 vn_syncer_add_to_worklist(bo, syncdelay); 3525 BO_UNLOCK(bo); 3526 3527 /* 3528 * Walk the list of vnodes pushing all that are dirty and 3529 * not already on the sync list. 3530 */ 3531 mtx_lock(&mountlist_mtx); 3532 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) { 3533 mtx_unlock(&mountlist_mtx); 3534 return (0); 3535 } 3536 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3537 vfs_unbusy(mp); 3538 return (0); 3539 } 3540 MNT_ILOCK(mp); 3541 mp->mnt_noasync++; 3542 mp->mnt_kern_flag &= ~MNTK_ASYNC; 3543 MNT_IUNLOCK(mp); 3544 vfs_msync(mp, MNT_NOWAIT); 3545 error = VFS_SYNC(mp, MNT_LAZY); 3546 MNT_ILOCK(mp); 3547 mp->mnt_noasync--; 3548 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 3549 mp->mnt_kern_flag |= MNTK_ASYNC; 3550 MNT_IUNLOCK(mp); 3551 vn_finished_write(mp); 3552 vfs_unbusy(mp); 3553 return (error); 3554 } 3555 3556 /* 3557 * The syncer vnode is no referenced. 3558 */ 3559 static int 3560 sync_inactive(struct vop_inactive_args *ap) 3561 { 3562 3563 vgone(ap->a_vp); 3564 return (0); 3565 } 3566 3567 /* 3568 * The syncer vnode is no longer needed and is being decommissioned. 3569 * 3570 * Modifications to the worklist must be protected by sync_mtx. 3571 */ 3572 static int 3573 sync_reclaim(struct vop_reclaim_args *ap) 3574 { 3575 struct vnode *vp = ap->a_vp; 3576 struct bufobj *bo; 3577 3578 bo = &vp->v_bufobj; 3579 BO_LOCK(bo); 3580 mtx_lock(&sync_mtx); 3581 if (vp->v_mount->mnt_syncer == vp) 3582 vp->v_mount->mnt_syncer = NULL; 3583 if (bo->bo_flag & BO_ONWORKLST) { 3584 LIST_REMOVE(bo, bo_synclist); 3585 syncer_worklist_len--; 3586 sync_vnode_count--; 3587 bo->bo_flag &= ~BO_ONWORKLST; 3588 } 3589 mtx_unlock(&sync_mtx); 3590 BO_UNLOCK(bo); 3591 3592 return (0); 3593 } 3594 3595 /* 3596 * Check if vnode represents a disk device 3597 */ 3598 int 3599 vn_isdisk(struct vnode *vp, int *errp) 3600 { 3601 int error; 3602 3603 error = 0; 3604 dev_lock(); 3605 if (vp->v_type != VCHR) 3606 error = ENOTBLK; 3607 else if (vp->v_rdev == NULL) 3608 error = ENXIO; 3609 else if (vp->v_rdev->si_devsw == NULL) 3610 error = ENXIO; 3611 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) 3612 error = ENOTBLK; 3613 dev_unlock(); 3614 if (errp != NULL) 3615 *errp = error; 3616 return (error == 0); 3617 } 3618 3619 /* 3620 * Common filesystem object access control check routine. Accepts a 3621 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3622 * and optional call-by-reference privused argument allowing vaccess() 3623 * to indicate to the caller whether privilege was used to satisfy the 3624 * request (obsoleted). Returns 0 on success, or an errno on failure. 3625 */ 3626 int 3627 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, 3628 accmode_t accmode, struct ucred *cred, int *privused) 3629 { 3630 accmode_t dac_granted; 3631 accmode_t priv_granted; 3632 3633 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, 3634 ("invalid bit in accmode")); 3635 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), 3636 ("VAPPEND without VWRITE")); 3637 3638 /* 3639 * Look for a normal, non-privileged way to access the file/directory 3640 * as requested. If it exists, go with that. 3641 */ 3642 3643 if (privused != NULL) 3644 *privused = 0; 3645 3646 dac_granted = 0; 3647 3648 /* Check the owner. */ 3649 if (cred->cr_uid == file_uid) { 3650 dac_granted |= VADMIN; 3651 if (file_mode & S_IXUSR) 3652 dac_granted |= VEXEC; 3653 if (file_mode & S_IRUSR) 3654 dac_granted |= VREAD; 3655 if (file_mode & S_IWUSR) 3656 dac_granted |= (VWRITE | VAPPEND); 3657 3658 if ((accmode & dac_granted) == accmode) 3659 return (0); 3660 3661 goto privcheck; 3662 } 3663 3664 /* Otherwise, check the groups (first match) */ 3665 if (groupmember(file_gid, cred)) { 3666 if (file_mode & S_IXGRP) 3667 dac_granted |= VEXEC; 3668 if (file_mode & S_IRGRP) 3669 dac_granted |= VREAD; 3670 if (file_mode & S_IWGRP) 3671 dac_granted |= (VWRITE | VAPPEND); 3672 3673 if ((accmode & dac_granted) == accmode) 3674 return (0); 3675 3676 goto privcheck; 3677 } 3678 3679 /* Otherwise, check everyone else. */ 3680 if (file_mode & S_IXOTH) 3681 dac_granted |= VEXEC; 3682 if (file_mode & S_IROTH) 3683 dac_granted |= VREAD; 3684 if (file_mode & S_IWOTH) 3685 dac_granted |= (VWRITE | VAPPEND); 3686 if ((accmode & dac_granted) == accmode) 3687 return (0); 3688 3689 privcheck: 3690 /* 3691 * Build a privilege mask to determine if the set of privileges 3692 * satisfies the requirements when combined with the granted mask 3693 * from above. For each privilege, if the privilege is required, 3694 * bitwise or the request type onto the priv_granted mask. 3695 */ 3696 priv_granted = 0; 3697 3698 if (type == VDIR) { 3699 /* 3700 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC 3701 * requests, instead of PRIV_VFS_EXEC. 3702 */ 3703 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3704 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) 3705 priv_granted |= VEXEC; 3706 } else { 3707 /* 3708 * Ensure that at least one execute bit is on. Otherwise, 3709 * a privileged user will always succeed, and we don't want 3710 * this to happen unless the file really is executable. 3711 */ 3712 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3713 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && 3714 !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) 3715 priv_granted |= VEXEC; 3716 } 3717 3718 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && 3719 !priv_check_cred(cred, PRIV_VFS_READ, 0)) 3720 priv_granted |= VREAD; 3721 3722 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3723 !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) 3724 priv_granted |= (VWRITE | VAPPEND); 3725 3726 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3727 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) 3728 priv_granted |= VADMIN; 3729 3730 if ((accmode & (priv_granted | dac_granted)) == accmode) { 3731 /* XXX audit: privilege used */ 3732 if (privused != NULL) 3733 *privused = 1; 3734 return (0); 3735 } 3736 3737 return ((accmode & VADMIN) ? EPERM : EACCES); 3738 } 3739 3740 /* 3741 * Credential check based on process requesting service, and per-attribute 3742 * permissions. 3743 */ 3744 int 3745 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, 3746 struct thread *td, accmode_t accmode) 3747 { 3748 3749 /* 3750 * Kernel-invoked always succeeds. 3751 */ 3752 if (cred == NOCRED) 3753 return (0); 3754 3755 /* 3756 * Do not allow privileged processes in jail to directly manipulate 3757 * system attributes. 3758 */ 3759 switch (attrnamespace) { 3760 case EXTATTR_NAMESPACE_SYSTEM: 3761 /* Potentially should be: return (EPERM); */ 3762 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); 3763 case EXTATTR_NAMESPACE_USER: 3764 return (VOP_ACCESS(vp, accmode, cred, td)); 3765 default: 3766 return (EPERM); 3767 } 3768 } 3769 3770 #ifdef DEBUG_VFS_LOCKS 3771 /* 3772 * This only exists to supress warnings from unlocked specfs accesses. It is 3773 * no longer ok to have an unlocked VFS. 3774 */ 3775 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ 3776 (vp)->v_type == VCHR || (vp)->v_type == VBAD) 3777 3778 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ 3779 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, 3780 "Drop into debugger on lock violation"); 3781 3782 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ 3783 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 3784 0, "Check for interlock across VOPs"); 3785 3786 int vfs_badlock_print = 1; /* Print lock violations. */ 3787 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 3788 0, "Print lock violations"); 3789 3790 #ifdef KDB 3791 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ 3792 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, 3793 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations"); 3794 #endif 3795 3796 static void 3797 vfs_badlock(const char *msg, const char *str, struct vnode *vp) 3798 { 3799 3800 #ifdef KDB 3801 if (vfs_badlock_backtrace) 3802 kdb_backtrace(); 3803 #endif 3804 if (vfs_badlock_print) 3805 printf("%s: %p %s\n", str, (void *)vp, msg); 3806 if (vfs_badlock_ddb) 3807 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3808 } 3809 3810 void 3811 assert_vi_locked(struct vnode *vp, const char *str) 3812 { 3813 3814 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) 3815 vfs_badlock("interlock is not locked but should be", str, vp); 3816 } 3817 3818 void 3819 assert_vi_unlocked(struct vnode *vp, const char *str) 3820 { 3821 3822 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) 3823 vfs_badlock("interlock is locked but should not be", str, vp); 3824 } 3825 3826 void 3827 assert_vop_locked(struct vnode *vp, const char *str) 3828 { 3829 3830 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == 0) 3831 vfs_badlock("is not locked but should be", str, vp); 3832 } 3833 3834 void 3835 assert_vop_unlocked(struct vnode *vp, const char *str) 3836 { 3837 3838 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 3839 vfs_badlock("is locked but should not be", str, vp); 3840 } 3841 3842 void 3843 assert_vop_elocked(struct vnode *vp, const char *str) 3844 { 3845 3846 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) 3847 vfs_badlock("is not exclusive locked but should be", str, vp); 3848 } 3849 3850 #if 0 3851 void 3852 assert_vop_elocked_other(struct vnode *vp, const char *str) 3853 { 3854 3855 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER) 3856 vfs_badlock("is not exclusive locked by another thread", 3857 str, vp); 3858 } 3859 3860 void 3861 assert_vop_slocked(struct vnode *vp, const char *str) 3862 { 3863 3864 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED) 3865 vfs_badlock("is not locked shared but should be", str, vp); 3866 } 3867 #endif /* 0 */ 3868 #endif /* DEBUG_VFS_LOCKS */ 3869 3870 void 3871 vop_rename_fail(struct vop_rename_args *ap) 3872 { 3873 3874 if (ap->a_tvp != NULL) 3875 vput(ap->a_tvp); 3876 if (ap->a_tdvp == ap->a_tvp) 3877 vrele(ap->a_tdvp); 3878 else 3879 vput(ap->a_tdvp); 3880 vrele(ap->a_fdvp); 3881 vrele(ap->a_fvp); 3882 } 3883 3884 void 3885 vop_rename_pre(void *ap) 3886 { 3887 struct vop_rename_args *a = ap; 3888 3889 #ifdef DEBUG_VFS_LOCKS 3890 if (a->a_tvp) 3891 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); 3892 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); 3893 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); 3894 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); 3895 3896 /* Check the source (from). */ 3897 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock && 3898 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) 3899 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); 3900 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) 3901 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked"); 3902 3903 /* Check the target. */ 3904 if (a->a_tvp) 3905 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); 3906 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); 3907 #endif 3908 if (a->a_tdvp != a->a_fdvp) 3909 vhold(a->a_fdvp); 3910 if (a->a_tvp != a->a_fvp) 3911 vhold(a->a_fvp); 3912 vhold(a->a_tdvp); 3913 if (a->a_tvp) 3914 vhold(a->a_tvp); 3915 } 3916 3917 void 3918 vop_strategy_pre(void *ap) 3919 { 3920 #ifdef DEBUG_VFS_LOCKS 3921 struct vop_strategy_args *a; 3922 struct buf *bp; 3923 3924 a = ap; 3925 bp = a->a_bp; 3926 3927 /* 3928 * Cluster ops lock their component buffers but not the IO container. 3929 */ 3930 if ((bp->b_flags & B_CLUSTER) != 0) 3931 return; 3932 3933 if (panicstr == NULL && !BUF_ISLOCKED(bp)) { 3934 if (vfs_badlock_print) 3935 printf( 3936 "VOP_STRATEGY: bp is not locked but should be\n"); 3937 if (vfs_badlock_ddb) 3938 kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); 3939 } 3940 #endif 3941 } 3942 3943 void 3944 vop_lookup_pre(void *ap) 3945 { 3946 #ifdef DEBUG_VFS_LOCKS 3947 struct vop_lookup_args *a; 3948 struct vnode *dvp; 3949 3950 a = ap; 3951 dvp = a->a_dvp; 3952 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3953 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3954 #endif 3955 } 3956 3957 void 3958 vop_lookup_post(void *ap, int rc) 3959 { 3960 #ifdef DEBUG_VFS_LOCKS 3961 struct vop_lookup_args *a; 3962 struct vnode *dvp; 3963 struct vnode *vp; 3964 3965 a = ap; 3966 dvp = a->a_dvp; 3967 vp = *(a->a_vpp); 3968 3969 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); 3970 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 3971 3972 if (!rc) 3973 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); 3974 #endif 3975 } 3976 3977 void 3978 vop_lock_pre(void *ap) 3979 { 3980 #ifdef DEBUG_VFS_LOCKS 3981 struct vop_lock1_args *a = ap; 3982 3983 if ((a->a_flags & LK_INTERLOCK) == 0) 3984 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3985 else 3986 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); 3987 #endif 3988 } 3989 3990 void 3991 vop_lock_post(void *ap, int rc) 3992 { 3993 #ifdef DEBUG_VFS_LOCKS 3994 struct vop_lock1_args *a = ap; 3995 3996 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); 3997 if (rc == 0) 3998 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); 3999 #endif 4000 } 4001 4002 void 4003 vop_unlock_pre(void *ap) 4004 { 4005 #ifdef DEBUG_VFS_LOCKS 4006 struct vop_unlock_args *a = ap; 4007 4008 if (a->a_flags & LK_INTERLOCK) 4009 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); 4010 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); 4011 #endif 4012 } 4013 4014 void 4015 vop_unlock_post(void *ap, int rc) 4016 { 4017 #ifdef DEBUG_VFS_LOCKS 4018 struct vop_unlock_args *a = ap; 4019 4020 if (a->a_flags & LK_INTERLOCK) 4021 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); 4022 #endif 4023 } 4024 4025 void 4026 vop_create_post(void *ap, int rc) 4027 { 4028 struct vop_create_args *a = ap; 4029 4030 if (!rc) 4031 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4032 } 4033 4034 void 4035 vop_link_post(void *ap, int rc) 4036 { 4037 struct vop_link_args *a = ap; 4038 4039 if (!rc) { 4040 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); 4041 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); 4042 } 4043 } 4044 4045 void 4046 vop_mkdir_post(void *ap, int rc) 4047 { 4048 struct vop_mkdir_args *a = ap; 4049 4050 if (!rc) 4051 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4052 } 4053 4054 void 4055 vop_mknod_post(void *ap, int rc) 4056 { 4057 struct vop_mknod_args *a = ap; 4058 4059 if (!rc) 4060 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4061 } 4062 4063 void 4064 vop_remove_post(void *ap, int rc) 4065 { 4066 struct vop_remove_args *a = ap; 4067 4068 if (!rc) { 4069 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4070 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4071 } 4072 } 4073 4074 void 4075 vop_rename_post(void *ap, int rc) 4076 { 4077 struct vop_rename_args *a = ap; 4078 4079 if (!rc) { 4080 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); 4081 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); 4082 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); 4083 if (a->a_tvp) 4084 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); 4085 } 4086 if (a->a_tdvp != a->a_fdvp) 4087 vdrop(a->a_fdvp); 4088 if (a->a_tvp != a->a_fvp) 4089 vdrop(a->a_fvp); 4090 vdrop(a->a_tdvp); 4091 if (a->a_tvp) 4092 vdrop(a->a_tvp); 4093 } 4094 4095 void 4096 vop_rmdir_post(void *ap, int rc) 4097 { 4098 struct vop_rmdir_args *a = ap; 4099 4100 if (!rc) { 4101 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); 4102 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); 4103 } 4104 } 4105 4106 void 4107 vop_setattr_post(void *ap, int rc) 4108 { 4109 struct vop_setattr_args *a = ap; 4110 4111 if (!rc) 4112 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); 4113 } 4114 4115 void 4116 vop_symlink_post(void *ap, int rc) 4117 { 4118 struct vop_symlink_args *a = ap; 4119 4120 if (!rc) 4121 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); 4122 } 4123 4124 static struct knlist fs_knlist; 4125 4126 static void 4127 vfs_event_init(void *arg) 4128 { 4129 knlist_init_mtx(&fs_knlist, NULL); 4130 } 4131 /* XXX - correct order? */ 4132 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); 4133 4134 void 4135 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused) 4136 { 4137 4138 KNOTE_UNLOCKED(&fs_knlist, event); 4139 } 4140 4141 static int filt_fsattach(struct knote *kn); 4142 static void filt_fsdetach(struct knote *kn); 4143 static int filt_fsevent(struct knote *kn, long hint); 4144 4145 struct filterops fs_filtops = { 4146 .f_isfd = 0, 4147 .f_attach = filt_fsattach, 4148 .f_detach = filt_fsdetach, 4149 .f_event = filt_fsevent 4150 }; 4151 4152 static int 4153 filt_fsattach(struct knote *kn) 4154 { 4155 4156 kn->kn_flags |= EV_CLEAR; 4157 knlist_add(&fs_knlist, kn, 0); 4158 return (0); 4159 } 4160 4161 static void 4162 filt_fsdetach(struct knote *kn) 4163 { 4164 4165 knlist_remove(&fs_knlist, kn, 0); 4166 } 4167 4168 static int 4169 filt_fsevent(struct knote *kn, long hint) 4170 { 4171 4172 kn->kn_fflags |= hint; 4173 return (kn->kn_fflags != 0); 4174 } 4175 4176 static int 4177 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) 4178 { 4179 struct vfsidctl vc; 4180 int error; 4181 struct mount *mp; 4182 4183 error = SYSCTL_IN(req, &vc, sizeof(vc)); 4184 if (error) 4185 return (error); 4186 if (vc.vc_vers != VFS_CTL_VERS1) 4187 return (EINVAL); 4188 mp = vfs_getvfs(&vc.vc_fsid); 4189 if (mp == NULL) 4190 return (ENOENT); 4191 /* ensure that a specific sysctl goes to the right filesystem. */ 4192 if (strcmp(vc.vc_fstypename, "*") != 0 && 4193 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { 4194 vfs_rel(mp); 4195 return (EINVAL); 4196 } 4197 VCTLTOREQ(&vc, req); 4198 error = VFS_SYSCTL(mp, vc.vc_op, req); 4199 vfs_rel(mp); 4200 return (error); 4201 } 4202 4203 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR, 4204 NULL, 0, sysctl_vfs_ctl, "", 4205 "Sysctl by fsid"); 4206 4207 /* 4208 * Function to initialize a va_filerev field sensibly. 4209 * XXX: Wouldn't a random number make a lot more sense ?? 4210 */ 4211 u_quad_t 4212 init_va_filerev(void) 4213 { 4214 struct bintime bt; 4215 4216 getbinuptime(&bt); 4217 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); 4218 } 4219 4220 static int filt_vfsread(struct knote *kn, long hint); 4221 static int filt_vfswrite(struct knote *kn, long hint); 4222 static int filt_vfsvnode(struct knote *kn, long hint); 4223 static void filt_vfsdetach(struct knote *kn); 4224 static struct filterops vfsread_filtops = { 4225 .f_isfd = 1, 4226 .f_detach = filt_vfsdetach, 4227 .f_event = filt_vfsread 4228 }; 4229 static struct filterops vfswrite_filtops = { 4230 .f_isfd = 1, 4231 .f_detach = filt_vfsdetach, 4232 .f_event = filt_vfswrite 4233 }; 4234 static struct filterops vfsvnode_filtops = { 4235 .f_isfd = 1, 4236 .f_detach = filt_vfsdetach, 4237 .f_event = filt_vfsvnode 4238 }; 4239 4240 static void 4241 vfs_knllock(void *arg) 4242 { 4243 struct vnode *vp = arg; 4244 4245 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 4246 } 4247 4248 static void 4249 vfs_knlunlock(void *arg) 4250 { 4251 struct vnode *vp = arg; 4252 4253 VOP_UNLOCK(vp, 0); 4254 } 4255 4256 static void 4257 vfs_knl_assert_locked(void *arg) 4258 { 4259 #ifdef DEBUG_VFS_LOCKS 4260 struct vnode *vp = arg; 4261 4262 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); 4263 #endif 4264 } 4265 4266 static void 4267 vfs_knl_assert_unlocked(void *arg) 4268 { 4269 #ifdef DEBUG_VFS_LOCKS 4270 struct vnode *vp = arg; 4271 4272 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); 4273 #endif 4274 } 4275 4276 int 4277 vfs_kqfilter(struct vop_kqfilter_args *ap) 4278 { 4279 struct vnode *vp = ap->a_vp; 4280 struct knote *kn = ap->a_kn; 4281 struct knlist *knl; 4282 4283 switch (kn->kn_filter) { 4284 case EVFILT_READ: 4285 kn->kn_fop = &vfsread_filtops; 4286 break; 4287 case EVFILT_WRITE: 4288 kn->kn_fop = &vfswrite_filtops; 4289 break; 4290 case EVFILT_VNODE: 4291 kn->kn_fop = &vfsvnode_filtops; 4292 break; 4293 default: 4294 return (EINVAL); 4295 } 4296 4297 kn->kn_hook = (caddr_t)vp; 4298 4299 v_addpollinfo(vp); 4300 if (vp->v_pollinfo == NULL) 4301 return (ENOMEM); 4302 knl = &vp->v_pollinfo->vpi_selinfo.si_note; 4303 knlist_add(knl, kn, 0); 4304 4305 return (0); 4306 } 4307 4308 /* 4309 * Detach knote from vnode 4310 */ 4311 static void 4312 filt_vfsdetach(struct knote *kn) 4313 { 4314 struct vnode *vp = (struct vnode *)kn->kn_hook; 4315 4316 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); 4317 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); 4318 } 4319 4320 /*ARGSUSED*/ 4321 static int 4322 filt_vfsread(struct knote *kn, long hint) 4323 { 4324 struct vnode *vp = (struct vnode *)kn->kn_hook; 4325 struct vattr va; 4326 int res; 4327 4328 /* 4329 * filesystem is gone, so set the EOF flag and schedule 4330 * the knote for deletion. 4331 */ 4332 if (hint == NOTE_REVOKE) { 4333 VI_LOCK(vp); 4334 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 4335 VI_UNLOCK(vp); 4336 return (1); 4337 } 4338 4339 if (VOP_GETATTR(vp, &va, curthread->td_ucred)) 4340 return (0); 4341 4342 VI_LOCK(vp); 4343 kn->kn_data = va.va_size - kn->kn_fp->f_offset; 4344 res = (kn->kn_data != 0); 4345 VI_UNLOCK(vp); 4346 return (res); 4347 } 4348 4349 /*ARGSUSED*/ 4350 static int 4351 filt_vfswrite(struct knote *kn, long hint) 4352 { 4353 struct vnode *vp = (struct vnode *)kn->kn_hook; 4354 4355 VI_LOCK(vp); 4356 4357 /* 4358 * filesystem is gone, so set the EOF flag and schedule 4359 * the knote for deletion. 4360 */ 4361 if (hint == NOTE_REVOKE) 4362 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 4363 4364 kn->kn_data = 0; 4365 VI_UNLOCK(vp); 4366 return (1); 4367 } 4368 4369 static int 4370 filt_vfsvnode(struct knote *kn, long hint) 4371 { 4372 struct vnode *vp = (struct vnode *)kn->kn_hook; 4373 int res; 4374 4375 VI_LOCK(vp); 4376 if (kn->kn_sfflags & hint) 4377 kn->kn_fflags |= hint; 4378 if (hint == NOTE_REVOKE) { 4379 kn->kn_flags |= EV_EOF; 4380 VI_UNLOCK(vp); 4381 return (1); 4382 } 4383 res = (kn->kn_fflags != 0); 4384 VI_UNLOCK(vp); 4385 return (res); 4386 } 4387 4388 int 4389 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) 4390 { 4391 int error; 4392 4393 if (dp->d_reclen > ap->a_uio->uio_resid) 4394 return (ENAMETOOLONG); 4395 error = uiomove(dp, dp->d_reclen, ap->a_uio); 4396 if (error) { 4397 if (ap->a_ncookies != NULL) { 4398 if (ap->a_cookies != NULL) 4399 free(ap->a_cookies, M_TEMP); 4400 ap->a_cookies = NULL; 4401 *ap->a_ncookies = 0; 4402 } 4403 return (error); 4404 } 4405 if (ap->a_ncookies == NULL) 4406 return (0); 4407 4408 KASSERT(ap->a_cookies, 4409 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); 4410 4411 *ap->a_cookies = realloc(*ap->a_cookies, 4412 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); 4413 (*ap->a_cookies)[*ap->a_ncookies] = off; 4414 return (0); 4415 } 4416 4417 /* 4418 * Mark for update the access time of the file if the filesystem 4419 * supports VOP_MARKATIME. This functionality is used by execve and 4420 * mmap, so we want to avoid the I/O implied by directly setting 4421 * va_atime for the sake of efficiency. 4422 */ 4423 void 4424 vfs_mark_atime(struct vnode *vp, struct ucred *cred) 4425 { 4426 struct mount *mp; 4427 4428 mp = vp->v_mount; 4429 VFS_ASSERT_GIANT(mp); 4430 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); 4431 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) 4432 (void)VOP_MARKATIME(vp); 4433 } 4434 4435 /* 4436 * The purpose of this routine is to remove granularity from accmode_t, 4437 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, 4438 * VADMIN and VAPPEND. 4439 * 4440 * If it returns 0, the caller is supposed to continue with the usual 4441 * access checks using 'accmode' as modified by this routine. If it 4442 * returns nonzero value, the caller is supposed to return that value 4443 * as errno. 4444 * 4445 * Note that after this routine runs, accmode may be zero. 4446 */ 4447 int 4448 vfs_unixify_accmode(accmode_t *accmode) 4449 { 4450 /* 4451 * There is no way to specify explicit "deny" rule using 4452 * file mode or POSIX.1e ACLs. 4453 */ 4454 if (*accmode & VEXPLICIT_DENY) { 4455 *accmode = 0; 4456 return (0); 4457 } 4458 4459 /* 4460 * None of these can be translated into usual access bits. 4461 * Also, the common case for NFSv4 ACLs is to not contain 4462 * either of these bits. Caller should check for VWRITE 4463 * on the containing directory instead. 4464 */ 4465 if (*accmode & (VDELETE_CHILD | VDELETE)) 4466 return (EPERM); 4467 4468 if (*accmode & VADMIN_PERMS) { 4469 *accmode &= ~VADMIN_PERMS; 4470 *accmode |= VADMIN; 4471 } 4472 4473 /* 4474 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL 4475 * or VSYNCHRONIZE using file mode or POSIX.1e ACL. 4476 */ 4477 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); 4478 4479 return (0); 4480 } 4481