FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_subr.c
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_mac.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/conf.h>
52 #include <sys/dirent.h>
53 #include <sys/event.h>
54 #include <sys/eventhandler.h>
55 #include <sys/extattr.h>
56 #include <sys/file.h>
57 #include <sys/fcntl.h>
58 #include <sys/jail.h>
59 #include <sys/kdb.h>
60 #include <sys/kernel.h>
61 #include <sys/kthread.h>
62 #include <sys/malloc.h>
63 #include <sys/mount.h>
64 #include <sys/namei.h>
65 #include <sys/priv.h>
66 #include <sys/reboot.h>
67 #include <sys/sleepqueue.h>
68 #include <sys/stat.h>
69 #include <sys/sysctl.h>
70 #include <sys/syslog.h>
71 #include <sys/vmmeter.h>
72 #include <sys/vnode.h>
73
74 #include <machine/stdarg.h>
75
76 #include <security/mac/mac_framework.h>
77
78 #include <vm/vm.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_extern.h>
81 #include <vm/pmap.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_page.h>
84 #include <vm/vm_kern.h>
85 #include <vm/uma.h>
86
87 #ifdef DDB
88 #include <ddb/ddb.h>
89 #endif
90
91 static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure");
92
93 static void delmntque(struct vnode *vp);
94 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
95 int slpflag, int slptimeo);
96 static void syncer_shutdown(void *arg, int howto);
97 static int vtryrecycle(struct vnode *vp);
98 static void vbusy(struct vnode *vp);
99 static void vinactive(struct vnode *, struct thread *);
100 static void v_incr_usecount(struct vnode *);
101 static void v_decr_usecount(struct vnode *);
102 static void v_decr_useonly(struct vnode *);
103 static void v_upgrade_usecount(struct vnode *);
104 static void vfree(struct vnode *);
105 static void vnlru_free(int);
106 static void vdestroy(struct vnode *);
107 static void vgonel(struct vnode *);
108 static void vfs_knllock(void *arg);
109 static void vfs_knlunlock(void *arg);
110 static int vfs_knllocked(void *arg);
111
112
113 /*
114 * Enable Giant pushdown based on whether or not the vm is mpsafe in this
115 * build. Without mpsafevm the buffer cache can not run Giant free.
116 */
117 int mpsafe_vfs = 1;
118 TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs);
119 SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0,
120 "MPSAFE VFS");
121
122 /*
123 * Number of vnodes in existence. Increased whenever getnewvnode()
124 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed
125 * vnode.
126 */
127 static unsigned long numvnodes;
128
129 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
130
131 /*
132 * Conversion tables for conversion from vnode types to inode formats
133 * and back.
134 */
135 enum vtype iftovt_tab[16] = {
136 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
137 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
138 };
139 int vttoif_tab[10] = {
140 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
141 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
142 };
143
144 /*
145 * List of vnodes that are ready for recycling.
146 */
147 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
148
149 /*
150 * Free vnode target. Free vnodes may simply be files which have been stat'd
151 * but not read. This is somewhat common, and a small cache of such files
152 * should be kept to avoid recreation costs.
153 */
154 static u_long wantfreevnodes;
155 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
156 /* Number of vnodes in the free list. */
157 static u_long freevnodes;
158 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
159
160 /*
161 * Various variables used for debugging the new implementation of
162 * reassignbuf().
163 * XXX these are probably of (very) limited utility now.
164 */
165 static int reassignbufcalls;
166 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
167
168 /*
169 * Cache for the mount type id assigned to NFS. This is used for
170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
171 */
172 int nfs_mount_type = -1;
173
174 /* To keep more than one thread at a time from running vfs_getnewfsid */
175 static struct mtx mntid_mtx;
176
177 /*
178 * Lock for any access to the following:
179 * vnode_free_list
180 * numvnodes
181 * freevnodes
182 */
183 static struct mtx vnode_free_list_mtx;
184
185 /* Publicly exported FS */
186 struct nfs_public nfs_pub;
187
188 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
189 static uma_zone_t vnode_zone;
190 static uma_zone_t vnodepoll_zone;
191
192 /* Set to 1 to print out reclaim of active vnodes */
193 int prtactive;
194
195 /*
196 * The workitem queue.
197 *
198 * It is useful to delay writes of file data and filesystem metadata
199 * for tens of seconds so that quickly created and deleted files need
200 * not waste disk bandwidth being created and removed. To realize this,
201 * we append vnodes to a "workitem" queue. When running with a soft
202 * updates implementation, most pending metadata dependencies should
203 * not wait for more than a few seconds. Thus, mounted on block devices
204 * are delayed only about a half the time that file data is delayed.
205 * Similarly, directory updates are more critical, so are only delayed
206 * about a third the time that file data is delayed. Thus, there are
207 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
208 * one each second (driven off the filesystem syncer process). The
209 * syncer_delayno variable indicates the next queue that is to be processed.
210 * Items that need to be processed soon are placed in this queue:
211 *
212 * syncer_workitem_pending[syncer_delayno]
213 *
214 * A delay of fifteen seconds is done by placing the request fifteen
215 * entries later in the queue:
216 *
217 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
218 *
219 */
220 static int syncer_delayno;
221 static long syncer_mask;
222 LIST_HEAD(synclist, bufobj);
223 static struct synclist *syncer_workitem_pending;
224 /*
225 * The sync_mtx protects:
226 * bo->bo_synclist
227 * sync_vnode_count
228 * syncer_delayno
229 * syncer_state
230 * syncer_workitem_pending
231 * syncer_worklist_len
232 * rushjob
233 */
234 static struct mtx sync_mtx;
235
236 #define SYNCER_MAXDELAY 32
237 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
238 static int syncdelay = 30; /* max time to delay syncing data */
239 static int filedelay = 30; /* time to delay syncing files */
240 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, "");
241 static int dirdelay = 29; /* time to delay syncing directories */
242 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, "");
243 static int metadelay = 28; /* time to delay syncing metadata */
244 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, "");
245 static int rushjob; /* number of slots to run ASAP */
246 static int stat_rush_requests; /* number of times I/O speeded up */
247 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
248
249 /*
250 * When shutting down the syncer, run it at four times normal speed.
251 */
252 #define SYNCER_SHUTDOWN_SPEEDUP 4
253 static int sync_vnode_count;
254 static int syncer_worklist_len;
255 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
256 syncer_state;
257
258 /*
259 * Number of vnodes we want to exist at any one time. This is mostly used
260 * to size hash tables in vnode-related code. It is normally not used in
261 * getnewvnode(), as wantfreevnodes is normally nonzero.)
262 *
263 * XXX desiredvnodes is historical cruft and should not exist.
264 */
265 int desiredvnodes;
266 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
267 &desiredvnodes, 0, "Maximum number of vnodes");
268 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
269 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
270 static int vnlru_nowhere;
271 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
272 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
273
274 /*
275 * Macros to control when a vnode is freed and recycled. All require
276 * the vnode interlock.
277 */
278 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
279 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
280 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
281
282
283 /*
284 * Initialize the vnode management data structures.
285 */
286 #ifndef MAXVNODES_MAX
287 #define MAXVNODES_MAX 100000
288 #endif
289 static void
290 vntblinit(void *dummy __unused)
291 {
292
293 /*
294 * Desiredvnodes is a function of the physical memory size and
295 * the kernel's heap size. Specifically, desiredvnodes scales
296 * in proportion to the physical memory size until two fifths
297 * of the kernel's heap size is consumed by vnodes and vm
298 * objects.
299 */
300 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size /
301 (5 * (sizeof(struct vm_object) + sizeof(struct vnode))));
302 if (desiredvnodes > MAXVNODES_MAX) {
303 if (bootverbose)
304 printf("Reducing kern.maxvnodes %d -> %d\n",
305 desiredvnodes, MAXVNODES_MAX);
306 desiredvnodes = MAXVNODES_MAX;
307 }
308 wantfreevnodes = desiredvnodes / 4;
309 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
310 TAILQ_INIT(&vnode_free_list);
311 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
312 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
313 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
314 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
315 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
316 /*
317 * Initialize the filesystem syncer.
318 */
319 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
320 &syncer_mask);
321 syncer_maxdelay = syncer_mask + 1;
322 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
323 }
324 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL)
325
326
327 /*
328 * Mark a mount point as busy. Used to synchronize access and to delay
329 * unmounting. Interlock is not released on failure.
330 */
331 int
332 vfs_busy(struct mount *mp, int flags, struct mtx *interlkp,
333 struct thread *td)
334 {
335 int lkflags;
336
337 MNT_ILOCK(mp);
338 MNT_REF(mp);
339 if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
340 if (flags & LK_NOWAIT) {
341 MNT_REL(mp);
342 MNT_IUNLOCK(mp);
343 return (ENOENT);
344 }
345 if (interlkp)
346 mtx_unlock(interlkp);
347 mp->mnt_kern_flag |= MNTK_MWAIT;
348 /*
349 * Since all busy locks are shared except the exclusive
350 * lock granted when unmounting, the only place that a
351 * wakeup needs to be done is at the release of the
352 * exclusive lock at the end of dounmount.
353 */
354 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0);
355 MNT_REL(mp);
356 MNT_IUNLOCK(mp);
357 if (interlkp)
358 mtx_lock(interlkp);
359 return (ENOENT);
360 }
361 if (interlkp)
362 mtx_unlock(interlkp);
363 lkflags = LK_SHARED | LK_INTERLOCK;
364 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td))
365 panic("vfs_busy: unexpected lock failure");
366 return (0);
367 }
368
369 /*
370 * Free a busy filesystem.
371 */
372 void
373 vfs_unbusy(struct mount *mp, struct thread *td)
374 {
375
376 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
377 vfs_rel(mp);
378 }
379
380 /*
381 * Lookup a mount point by filesystem identifier.
382 */
383 struct mount *
384 vfs_getvfs(fsid_t *fsid)
385 {
386 struct mount *mp;
387
388 mtx_lock(&mountlist_mtx);
389 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
390 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
391 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
392 vfs_ref(mp);
393 mtx_unlock(&mountlist_mtx);
394 return (mp);
395 }
396 }
397 mtx_unlock(&mountlist_mtx);
398 return ((struct mount *) 0);
399 }
400
401 /*
402 * Check if a user can access privileged mount options.
403 */
404 int
405 vfs_suser(struct mount *mp, struct thread *td)
406 {
407 int error;
408
409 /*
410 * If the thread is jailed, but this is not a jail-friendly file
411 * system, deny immediately.
412 */
413 if (jailed(td->td_ucred) && !(mp->mnt_vfc->vfc_flags & VFCF_JAIL))
414 return (EPERM);
415
416 /*
417 * If the file system was mounted outside a jail and a jailed thread
418 * tries to access it, deny immediately.
419 */
420 if (!jailed(mp->mnt_cred) && jailed(td->td_ucred))
421 return (EPERM);
422
423 /*
424 * If the file system was mounted inside different jail that the jail of
425 * the calling thread, deny immediately.
426 */
427 if (jailed(mp->mnt_cred) && jailed(td->td_ucred) &&
428 mp->mnt_cred->cr_prison != td->td_ucred->cr_prison) {
429 return (EPERM);
430 }
431
432 if ((mp->mnt_flag & MNT_USER) == 0 ||
433 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
434 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
435 return (error);
436 }
437 return (0);
438 }
439
440 /*
441 * Get a new unique fsid. Try to make its val[0] unique, since this value
442 * will be used to create fake device numbers for stat(). Also try (but
443 * not so hard) make its val[0] unique mod 2^16, since some emulators only
444 * support 16-bit device numbers. We end up with unique val[0]'s for the
445 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
446 *
447 * Keep in mind that several mounts may be running in parallel. Starting
448 * the search one past where the previous search terminated is both a
449 * micro-optimization and a defense against returning the same fsid to
450 * different mounts.
451 */
452 void
453 vfs_getnewfsid(struct mount *mp)
454 {
455 static u_int16_t mntid_base;
456 struct mount *nmp;
457 fsid_t tfsid;
458 int mtype;
459
460 mtx_lock(&mntid_mtx);
461 mtype = mp->mnt_vfc->vfc_typenum;
462 tfsid.val[1] = mtype;
463 mtype = (mtype & 0xFF) << 24;
464 for (;;) {
465 tfsid.val[0] = makedev(255,
466 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
467 mntid_base++;
468 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
469 break;
470 vfs_rel(nmp);
471 }
472 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
473 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
474 mtx_unlock(&mntid_mtx);
475 }
476
477 /*
478 * Knob to control the precision of file timestamps:
479 *
480 * 0 = seconds only; nanoseconds zeroed.
481 * 1 = seconds and nanoseconds, accurate within 1/HZ.
482 * 2 = seconds and nanoseconds, truncated to microseconds.
483 * >=3 = seconds and nanoseconds, maximum precision.
484 */
485 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
486
487 static int timestamp_precision = TSP_SEC;
488 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
489 ×tamp_precision, 0, "");
490
491 /*
492 * Get a current timestamp.
493 */
494 void
495 vfs_timestamp(struct timespec *tsp)
496 {
497 struct timeval tv;
498
499 switch (timestamp_precision) {
500 case TSP_SEC:
501 tsp->tv_sec = time_second;
502 tsp->tv_nsec = 0;
503 break;
504 case TSP_HZ:
505 getnanotime(tsp);
506 break;
507 case TSP_USEC:
508 microtime(&tv);
509 TIMEVAL_TO_TIMESPEC(&tv, tsp);
510 break;
511 case TSP_NSEC:
512 default:
513 nanotime(tsp);
514 break;
515 }
516 }
517
518 /*
519 * Set vnode attributes to VNOVAL
520 */
521 void
522 vattr_null(struct vattr *vap)
523 {
524
525 vap->va_type = VNON;
526 vap->va_size = VNOVAL;
527 vap->va_bytes = VNOVAL;
528 vap->va_mode = VNOVAL;
529 vap->va_nlink = VNOVAL;
530 vap->va_uid = VNOVAL;
531 vap->va_gid = VNOVAL;
532 vap->va_fsid = VNOVAL;
533 vap->va_fileid = VNOVAL;
534 vap->va_blocksize = VNOVAL;
535 vap->va_rdev = VNOVAL;
536 vap->va_atime.tv_sec = VNOVAL;
537 vap->va_atime.tv_nsec = VNOVAL;
538 vap->va_mtime.tv_sec = VNOVAL;
539 vap->va_mtime.tv_nsec = VNOVAL;
540 vap->va_ctime.tv_sec = VNOVAL;
541 vap->va_ctime.tv_nsec = VNOVAL;
542 vap->va_birthtime.tv_sec = VNOVAL;
543 vap->va_birthtime.tv_nsec = VNOVAL;
544 vap->va_flags = VNOVAL;
545 vap->va_gen = VNOVAL;
546 vap->va_vaflags = 0;
547 }
548
549 /*
550 * This routine is called when we have too many vnodes. It attempts
551 * to free <count> vnodes and will potentially free vnodes that still
552 * have VM backing store (VM backing store is typically the cause
553 * of a vnode blowout so we want to do this). Therefore, this operation
554 * is not considered cheap.
555 *
556 * A number of conditions may prevent a vnode from being reclaimed.
557 * the buffer cache may have references on the vnode, a directory
558 * vnode may still have references due to the namei cache representing
559 * underlying files, or the vnode may be in active use. It is not
560 * desireable to reuse such vnodes. These conditions may cause the
561 * number of vnodes to reach some minimum value regardless of what
562 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
563 */
564 static int
565 vlrureclaim(struct mount *mp)
566 {
567 struct thread *td;
568 struct vnode *vp;
569 int done;
570 int trigger;
571 int usevnodes;
572 int count;
573
574 /*
575 * Calculate the trigger point, don't allow user
576 * screwups to blow us up. This prevents us from
577 * recycling vnodes with lots of resident pages. We
578 * aren't trying to free memory, we are trying to
579 * free vnodes.
580 */
581 usevnodes = desiredvnodes;
582 if (usevnodes <= 0)
583 usevnodes = 1;
584 trigger = cnt.v_page_count * 2 / usevnodes;
585 done = 0;
586 td = curthread;
587 vn_start_write(NULL, &mp, V_WAIT);
588 MNT_ILOCK(mp);
589 count = mp->mnt_nvnodelistsize / 10 + 1;
590 while (count != 0) {
591 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
592 while (vp != NULL && vp->v_type == VMARKER)
593 vp = TAILQ_NEXT(vp, v_nmntvnodes);
594 if (vp == NULL)
595 break;
596 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
597 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
598 --count;
599 if (!VI_TRYLOCK(vp))
600 goto next_iter;
601 /*
602 * If it's been deconstructed already, it's still
603 * referenced, or it exceeds the trigger, skip it.
604 */
605 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
606 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
607 vp->v_object->resident_page_count > trigger)) {
608 VI_UNLOCK(vp);
609 goto next_iter;
610 }
611 MNT_IUNLOCK(mp);
612 vholdl(vp);
613 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) {
614 vdrop(vp);
615 goto next_iter_mntunlocked;
616 }
617 VI_LOCK(vp);
618 /*
619 * v_usecount may have been bumped after VOP_LOCK() dropped
620 * the vnode interlock and before it was locked again.
621 *
622 * It is not necessary to recheck VI_DOOMED because it can
623 * only be set by another thread that holds both the vnode
624 * lock and vnode interlock. If another thread has the
625 * vnode lock before we get to VOP_LOCK() and obtains the
626 * vnode interlock after VOP_LOCK() drops the vnode
627 * interlock, the other thread will be unable to drop the
628 * vnode lock before our VOP_LOCK() call fails.
629 */
630 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
631 (vp->v_object != NULL &&
632 vp->v_object->resident_page_count > trigger)) {
633 VOP_UNLOCK(vp, LK_INTERLOCK, td);
634 goto next_iter_mntunlocked;
635 }
636 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
637 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
638 vgonel(vp);
639 VOP_UNLOCK(vp, 0, td);
640 vdropl(vp);
641 done++;
642 next_iter_mntunlocked:
643 if ((count % 256) != 0)
644 goto relock_mnt;
645 goto yield;
646 next_iter:
647 if ((count % 256) != 0)
648 continue;
649 MNT_IUNLOCK(mp);
650 yield:
651 uio_yield();
652 relock_mnt:
653 MNT_ILOCK(mp);
654 }
655 MNT_IUNLOCK(mp);
656 vn_finished_write(mp);
657 return done;
658 }
659
660 /*
661 * Attempt to keep the free list at wantfreevnodes length.
662 */
663 static void
664 vnlru_free(int count)
665 {
666 struct vnode *vp;
667 int vfslocked;
668
669 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
670 for (; count > 0; count--) {
671 vp = TAILQ_FIRST(&vnode_free_list);
672 /*
673 * The list can be modified while the free_list_mtx
674 * has been dropped and vp could be NULL here.
675 */
676 if (!vp)
677 break;
678 VNASSERT(vp->v_op != NULL, vp,
679 ("vnlru_free: vnode already reclaimed."));
680 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
681 /*
682 * Don't recycle if we can't get the interlock.
683 */
684 if (!VI_TRYLOCK(vp)) {
685 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
686 continue;
687 }
688 VNASSERT(VCANRECYCLE(vp), vp,
689 ("vp inconsistent on freelist"));
690 freevnodes--;
691 vp->v_iflag &= ~VI_FREE;
692 vholdl(vp);
693 mtx_unlock(&vnode_free_list_mtx);
694 VI_UNLOCK(vp);
695 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
696 vtryrecycle(vp);
697 VFS_UNLOCK_GIANT(vfslocked);
698 /*
699 * If the recycled succeeded this vdrop will actually free
700 * the vnode. If not it will simply place it back on
701 * the free list.
702 */
703 vdrop(vp);
704 mtx_lock(&vnode_free_list_mtx);
705 }
706 }
707 /*
708 * Attempt to recycle vnodes in a context that is always safe to block.
709 * Calling vlrurecycle() from the bowels of filesystem code has some
710 * interesting deadlock problems.
711 */
712 static struct proc *vnlruproc;
713 static int vnlruproc_sig;
714
715 static void
716 vnlru_proc(void)
717 {
718 struct mount *mp, *nmp;
719 int done;
720 struct proc *p = vnlruproc;
721 struct thread *td = curthread;
722
723 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
724 SHUTDOWN_PRI_FIRST);
725
726 mtx_lock(&Giant);
727
728 for (;;) {
729 kthread_suspend_check(p);
730 mtx_lock(&vnode_free_list_mtx);
731 if (freevnodes > wantfreevnodes)
732 vnlru_free(freevnodes - wantfreevnodes);
733 if (numvnodes <= desiredvnodes * 9 / 10) {
734 vnlruproc_sig = 0;
735 wakeup(&vnlruproc_sig);
736 msleep(vnlruproc, &vnode_free_list_mtx,
737 PVFS|PDROP, "vlruwt", hz);
738 continue;
739 }
740 mtx_unlock(&vnode_free_list_mtx);
741 done = 0;
742 mtx_lock(&mountlist_mtx);
743 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
744 int vfsunlocked;
745 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
746 nmp = TAILQ_NEXT(mp, mnt_list);
747 continue;
748 }
749 if (!VFS_NEEDSGIANT(mp)) {
750 mtx_unlock(&Giant);
751 vfsunlocked = 1;
752 } else
753 vfsunlocked = 0;
754 done += vlrureclaim(mp);
755 if (vfsunlocked)
756 mtx_lock(&Giant);
757 mtx_lock(&mountlist_mtx);
758 nmp = TAILQ_NEXT(mp, mnt_list);
759 vfs_unbusy(mp, td);
760 }
761 mtx_unlock(&mountlist_mtx);
762 if (done == 0) {
763 EVENTHANDLER_INVOKE(vfs_lowvnodes, desiredvnodes / 10);
764 #if 0
765 /* These messages are temporary debugging aids */
766 if (vnlru_nowhere < 5)
767 printf("vnlru process getting nowhere..\n");
768 else if (vnlru_nowhere == 5)
769 printf("vnlru process messages stopped.\n");
770 #endif
771 vnlru_nowhere++;
772 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
773 } else
774 uio_yield();
775 }
776 }
777
778 static struct kproc_desc vnlru_kp = {
779 "vnlru",
780 vnlru_proc,
781 &vnlruproc
782 };
783 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp)
784
785 /*
786 * Routines having to do with the management of the vnode table.
787 */
788
789 static void
790 vdestroy(struct vnode *vp)
791 {
792 struct bufobj *bo;
793
794 CTR1(KTR_VFS, "vdestroy vp %p", vp);
795 mtx_lock(&vnode_free_list_mtx);
796 numvnodes--;
797 mtx_unlock(&vnode_free_list_mtx);
798 bo = &vp->v_bufobj;
799 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
800 ("cleaned vnode still on the free list."));
801 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
802 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
803 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
804 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
805 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
806 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
807 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
808 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
809 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
810 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
811 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
812 VI_UNLOCK(vp);
813 #ifdef MAC
814 mac_destroy_vnode(vp);
815 #endif
816 if (vp->v_pollinfo != NULL) {
817 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note);
818 mtx_destroy(&vp->v_pollinfo->vpi_lock);
819 uma_zfree(vnodepoll_zone, vp->v_pollinfo);
820 }
821 #ifdef INVARIANTS
822 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */
823 vp->v_op = NULL;
824 #endif
825 lockdestroy(vp->v_vnlock);
826 mtx_destroy(&vp->v_interlock);
827 uma_zfree(vnode_zone, vp);
828 }
829
830 /*
831 * Try to recycle a freed vnode. We abort if anyone picks up a reference
832 * before we actually vgone(). This function must be called with the vnode
833 * held to prevent the vnode from being returned to the free list midway
834 * through vgone().
835 */
836 static int
837 vtryrecycle(struct vnode *vp)
838 {
839 struct thread *td = curthread;
840 struct mount *vnmp;
841
842 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp);
843 VNASSERT(vp->v_holdcnt, vp,
844 ("vtryrecycle: Recycling vp %p without a reference.", vp));
845 /*
846 * This vnode may found and locked via some other list, if so we
847 * can't recycle it yet.
848 */
849 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0)
850 return (EWOULDBLOCK);
851 /*
852 * Don't recycle if its filesystem is being suspended.
853 */
854 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
855 VOP_UNLOCK(vp, 0, td);
856 return (EBUSY);
857 }
858 /*
859 * If we got this far, we need to acquire the interlock and see if
860 * anyone picked up this vnode from another list. If not, we will
861 * mark it with DOOMED via vgonel() so that anyone who does find it
862 * will skip over it.
863 */
864 VI_LOCK(vp);
865 if (vp->v_usecount) {
866 VOP_UNLOCK(vp, LK_INTERLOCK, td);
867 vn_finished_write(vnmp);
868 return (EBUSY);
869 }
870 if ((vp->v_iflag & VI_DOOMED) == 0)
871 vgonel(vp);
872 VOP_UNLOCK(vp, LK_INTERLOCK, td);
873 vn_finished_write(vnmp);
874 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp);
875 return (0);
876 }
877
878 /*
879 * Return the next vnode from the free list.
880 */
881 int
882 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
883 struct vnode **vpp)
884 {
885 struct vnode *vp = NULL;
886 struct bufobj *bo;
887
888 mtx_lock(&vnode_free_list_mtx);
889 /*
890 * Lend our context to reclaim vnodes if they've exceeded the max.
891 */
892 if (freevnodes > wantfreevnodes)
893 vnlru_free(1);
894 /*
895 * Wait for available vnodes.
896 */
897 if (numvnodes > desiredvnodes) {
898 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
899 /*
900 * File system is beeing suspended, we cannot risk a
901 * deadlock here, so allocate new vnode anyway.
902 */
903 if (freevnodes > wantfreevnodes)
904 vnlru_free(freevnodes - wantfreevnodes);
905 goto alloc;
906 }
907 if (vnlruproc_sig == 0) {
908 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
909 wakeup(vnlruproc);
910 }
911 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
912 "vlruwk", hz);
913 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
914 if (numvnodes > desiredvnodes) {
915 mtx_unlock(&vnode_free_list_mtx);
916 return (ENFILE);
917 }
918 #endif
919 }
920 alloc:
921 numvnodes++;
922 mtx_unlock(&vnode_free_list_mtx);
923 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
924 /*
925 * Setup locks.
926 */
927 vp->v_vnlock = &vp->v_lock;
928 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
929 /*
930 * By default, don't allow shared locks unless filesystems
931 * opt-in.
932 */
933 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
934 /*
935 * Initialize bufobj.
936 */
937 bo = &vp->v_bufobj;
938 bo->__bo_vnode = vp;
939 bo->bo_mtx = &vp->v_interlock;
940 bo->bo_ops = &buf_ops_bio;
941 bo->bo_private = vp;
942 TAILQ_INIT(&bo->bo_clean.bv_hd);
943 TAILQ_INIT(&bo->bo_dirty.bv_hd);
944 /*
945 * Initialize namecache.
946 */
947 LIST_INIT(&vp->v_cache_src);
948 TAILQ_INIT(&vp->v_cache_dst);
949 /*
950 * Finalize various vnode identity bits.
951 */
952 vp->v_type = VNON;
953 vp->v_tag = tag;
954 vp->v_op = vops;
955 v_incr_usecount(vp);
956 vp->v_data = 0;
957 #ifdef MAC
958 mac_init_vnode(vp);
959 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
960 mac_associate_vnode_singlelabel(mp, vp);
961 else if (mp == NULL)
962 printf("NULL mp in getnewvnode()\n");
963 #endif
964 if (mp != NULL) {
965 bo->bo_bsize = mp->mnt_stat.f_iosize;
966 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
967 vp->v_vflag |= VV_NOKNOTE;
968 }
969
970 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp);
971 *vpp = vp;
972 return (0);
973 }
974
975 /*
976 * Delete from old mount point vnode list, if on one.
977 */
978 static void
979 delmntque(struct vnode *vp)
980 {
981 struct mount *mp;
982
983 mp = vp->v_mount;
984 if (mp == NULL)
985 return;
986 MNT_ILOCK(mp);
987 vp->v_mount = NULL;
988 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
989 ("bad mount point vnode list size"));
990 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
991 mp->mnt_nvnodelistsize--;
992 MNT_REL(mp);
993 MNT_IUNLOCK(mp);
994 }
995
996 static void
997 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
998 {
999 struct thread *td;
1000
1001 td = curthread; /* XXX ? */
1002 vp->v_data = NULL;
1003 vp->v_op = &dead_vnodeops;
1004 /* XXX non mp-safe fs may still call insmntque with vnode
1005 unlocked */
1006 if (!VOP_ISLOCKED(vp, td))
1007 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1008 vgone(vp);
1009 vput(vp);
1010 }
1011
1012 /*
1013 * Insert into list of vnodes for the new mount point, if available.
1014 */
1015 int
1016 insmntque1(struct vnode *vp, struct mount *mp,
1017 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1018 {
1019
1020 KASSERT(vp->v_mount == NULL,
1021 ("insmntque: vnode already on per mount vnode list"));
1022 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1023 MNT_ILOCK(mp);
1024 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1025 mp->mnt_nvnodelistsize == 0) {
1026 MNT_IUNLOCK(mp);
1027 if (dtr != NULL)
1028 dtr(vp, dtr_arg);
1029 return (EBUSY);
1030 }
1031 vp->v_mount = mp;
1032 MNT_REF(mp);
1033 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1034 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1035 ("neg mount point vnode list size"));
1036 mp->mnt_nvnodelistsize++;
1037 MNT_IUNLOCK(mp);
1038 return (0);
1039 }
1040
1041 int
1042 insmntque(struct vnode *vp, struct mount *mp)
1043 {
1044
1045 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1046 }
1047
1048 /*
1049 * Flush out and invalidate all buffers associated with a bufobj
1050 * Called with the underlying object locked.
1051 */
1052 int
1053 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag,
1054 int slptimeo)
1055 {
1056 int error;
1057
1058 BO_LOCK(bo);
1059 if (flags & V_SAVE) {
1060 error = bufobj_wwait(bo, slpflag, slptimeo);
1061 if (error) {
1062 BO_UNLOCK(bo);
1063 return (error);
1064 }
1065 if (bo->bo_dirty.bv_cnt > 0) {
1066 BO_UNLOCK(bo);
1067 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0)
1068 return (error);
1069 /*
1070 * XXX We could save a lock/unlock if this was only
1071 * enabled under INVARIANTS
1072 */
1073 BO_LOCK(bo);
1074 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1075 panic("vinvalbuf: dirty bufs");
1076 }
1077 }
1078 /*
1079 * If you alter this loop please notice that interlock is dropped and
1080 * reacquired in flushbuflist. Special care is needed to ensure that
1081 * no race conditions occur from this.
1082 */
1083 do {
1084 error = flushbuflist(&bo->bo_clean,
1085 flags, bo, slpflag, slptimeo);
1086 if (error == 0)
1087 error = flushbuflist(&bo->bo_dirty,
1088 flags, bo, slpflag, slptimeo);
1089 if (error != 0 && error != EAGAIN) {
1090 BO_UNLOCK(bo);
1091 return (error);
1092 }
1093 } while (error != 0);
1094
1095 /*
1096 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1097 * have write I/O in-progress but if there is a VM object then the
1098 * VM object can also have read-I/O in-progress.
1099 */
1100 do {
1101 bufobj_wwait(bo, 0, 0);
1102 BO_UNLOCK(bo);
1103 if (bo->bo_object != NULL) {
1104 VM_OBJECT_LOCK(bo->bo_object);
1105 vm_object_pip_wait(bo->bo_object, "bovlbx");
1106 VM_OBJECT_UNLOCK(bo->bo_object);
1107 }
1108 BO_LOCK(bo);
1109 } while (bo->bo_numoutput > 0);
1110 BO_UNLOCK(bo);
1111
1112 /*
1113 * Destroy the copy in the VM cache, too.
1114 */
1115 if (bo->bo_object != NULL) {
1116 VM_OBJECT_LOCK(bo->bo_object);
1117 vm_object_page_remove(bo->bo_object, 0, 0,
1118 (flags & V_SAVE) ? TRUE : FALSE);
1119 VM_OBJECT_UNLOCK(bo->bo_object);
1120 }
1121
1122 #ifdef INVARIANTS
1123 BO_LOCK(bo);
1124 if ((flags & (V_ALT | V_NORMAL)) == 0 &&
1125 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1126 panic("vinvalbuf: flush failed");
1127 BO_UNLOCK(bo);
1128 #endif
1129 return (0);
1130 }
1131
1132 /*
1133 * Flush out and invalidate all buffers associated with a vnode.
1134 * Called with the underlying object locked.
1135 */
1136 int
1137 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag,
1138 int slptimeo)
1139 {
1140
1141 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags);
1142 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1143 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo));
1144 }
1145
1146 /*
1147 * Flush out buffers on the specified list.
1148 *
1149 */
1150 static int
1151 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1152 int slptimeo)
1153 {
1154 struct buf *bp, *nbp;
1155 int retval, error;
1156 daddr_t lblkno;
1157 b_xflags_t xflags;
1158
1159 ASSERT_BO_LOCKED(bo);
1160
1161 retval = 0;
1162 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1163 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1164 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1165 continue;
1166 }
1167 lblkno = 0;
1168 xflags = 0;
1169 if (nbp != NULL) {
1170 lblkno = nbp->b_lblkno;
1171 xflags = nbp->b_xflags &
1172 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1173 }
1174 retval = EAGAIN;
1175 error = BUF_TIMELOCK(bp,
1176 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1177 "flushbuf", slpflag, slptimeo);
1178 if (error) {
1179 BO_LOCK(bo);
1180 return (error != ENOLCK ? error : EAGAIN);
1181 }
1182 KASSERT(bp->b_bufobj == bo,
1183 ("bp %p wrong b_bufobj %p should be %p",
1184 bp, bp->b_bufobj, bo));
1185 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1186 BUF_UNLOCK(bp);
1187 BO_LOCK(bo);
1188 return (EAGAIN);
1189 }
1190 /*
1191 * XXX Since there are no node locks for NFS, I
1192 * believe there is a slight chance that a delayed
1193 * write will occur while sleeping just above, so
1194 * check for it.
1195 */
1196 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1197 (flags & V_SAVE)) {
1198 bremfree(bp);
1199 bp->b_flags |= B_ASYNC;
1200 bwrite(bp);
1201 BO_LOCK(bo);
1202 return (EAGAIN); /* XXX: why not loop ? */
1203 }
1204 bremfree(bp);
1205 bp->b_flags |= (B_INVAL | B_RELBUF);
1206 bp->b_flags &= ~B_ASYNC;
1207 brelse(bp);
1208 BO_LOCK(bo);
1209 if (nbp != NULL &&
1210 (nbp->b_bufobj != bo ||
1211 nbp->b_lblkno != lblkno ||
1212 (nbp->b_xflags &
1213 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1214 break; /* nbp invalid */
1215 }
1216 return (retval);
1217 }
1218
1219 /*
1220 * Truncate a file's buffer and pages to a specified length. This
1221 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1222 * sync activity.
1223 */
1224 int
1225 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
1226 off_t length, int blksize)
1227 {
1228 struct buf *bp, *nbp;
1229 int anyfreed;
1230 int trunclbn;
1231 struct bufobj *bo;
1232
1233 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length);
1234 /*
1235 * Round up to the *next* lbn.
1236 */
1237 trunclbn = (length + blksize - 1) / blksize;
1238
1239 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1240 restart:
1241 VI_LOCK(vp);
1242 bo = &vp->v_bufobj;
1243 anyfreed = 1;
1244 for (;anyfreed;) {
1245 anyfreed = 0;
1246 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1247 if (bp->b_lblkno < trunclbn)
1248 continue;
1249 if (BUF_LOCK(bp,
1250 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1251 VI_MTX(vp)) == ENOLCK)
1252 goto restart;
1253
1254 bremfree(bp);
1255 bp->b_flags |= (B_INVAL | B_RELBUF);
1256 bp->b_flags &= ~B_ASYNC;
1257 brelse(bp);
1258 anyfreed = 1;
1259
1260 if (nbp != NULL &&
1261 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1262 (nbp->b_vp != vp) ||
1263 (nbp->b_flags & B_DELWRI))) {
1264 goto restart;
1265 }
1266 VI_LOCK(vp);
1267 }
1268
1269 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1270 if (bp->b_lblkno < trunclbn)
1271 continue;
1272 if (BUF_LOCK(bp,
1273 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1274 VI_MTX(vp)) == ENOLCK)
1275 goto restart;
1276 bremfree(bp);
1277 bp->b_flags |= (B_INVAL | B_RELBUF);
1278 bp->b_flags &= ~B_ASYNC;
1279 brelse(bp);
1280 anyfreed = 1;
1281 if (nbp != NULL &&
1282 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1283 (nbp->b_vp != vp) ||
1284 (nbp->b_flags & B_DELWRI) == 0)) {
1285 goto restart;
1286 }
1287 VI_LOCK(vp);
1288 }
1289 }
1290
1291 if (length > 0) {
1292 restartsync:
1293 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1294 if (bp->b_lblkno > 0)
1295 continue;
1296 /*
1297 * Since we hold the vnode lock this should only
1298 * fail if we're racing with the buf daemon.
1299 */
1300 if (BUF_LOCK(bp,
1301 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1302 VI_MTX(vp)) == ENOLCK) {
1303 goto restart;
1304 }
1305 VNASSERT((bp->b_flags & B_DELWRI), vp,
1306 ("buf(%p) on dirty queue without DELWRI", bp));
1307
1308 bremfree(bp);
1309 bawrite(bp);
1310 VI_LOCK(vp);
1311 goto restartsync;
1312 }
1313 }
1314
1315 bufobj_wwait(bo, 0, 0);
1316 VI_UNLOCK(vp);
1317 vnode_pager_setsize(vp, length);
1318
1319 return (0);
1320 }
1321
1322 /*
1323 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1324 * a vnode.
1325 *
1326 * NOTE: We have to deal with the special case of a background bitmap
1327 * buffer, a situation where two buffers will have the same logical
1328 * block offset. We want (1) only the foreground buffer to be accessed
1329 * in a lookup and (2) must differentiate between the foreground and
1330 * background buffer in the splay tree algorithm because the splay
1331 * tree cannot normally handle multiple entities with the same 'index'.
1332 * We accomplish this by adding differentiating flags to the splay tree's
1333 * numerical domain.
1334 */
1335 static
1336 struct buf *
1337 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1338 {
1339 struct buf dummy;
1340 struct buf *lefttreemax, *righttreemin, *y;
1341
1342 if (root == NULL)
1343 return (NULL);
1344 lefttreemax = righttreemin = &dummy;
1345 for (;;) {
1346 if (lblkno < root->b_lblkno ||
1347 (lblkno == root->b_lblkno &&
1348 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1349 if ((y = root->b_left) == NULL)
1350 break;
1351 if (lblkno < y->b_lblkno) {
1352 /* Rotate right. */
1353 root->b_left = y->b_right;
1354 y->b_right = root;
1355 root = y;
1356 if ((y = root->b_left) == NULL)
1357 break;
1358 }
1359 /* Link into the new root's right tree. */
1360 righttreemin->b_left = root;
1361 righttreemin = root;
1362 } else if (lblkno > root->b_lblkno ||
1363 (lblkno == root->b_lblkno &&
1364 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1365 if ((y = root->b_right) == NULL)
1366 break;
1367 if (lblkno > y->b_lblkno) {
1368 /* Rotate left. */
1369 root->b_right = y->b_left;
1370 y->b_left = root;
1371 root = y;
1372 if ((y = root->b_right) == NULL)
1373 break;
1374 }
1375 /* Link into the new root's left tree. */
1376 lefttreemax->b_right = root;
1377 lefttreemax = root;
1378 } else {
1379 break;
1380 }
1381 root = y;
1382 }
1383 /* Assemble the new root. */
1384 lefttreemax->b_right = root->b_left;
1385 righttreemin->b_left = root->b_right;
1386 root->b_left = dummy.b_right;
1387 root->b_right = dummy.b_left;
1388 return (root);
1389 }
1390
1391 static void
1392 buf_vlist_remove(struct buf *bp)
1393 {
1394 struct buf *root;
1395 struct bufv *bv;
1396
1397 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1398 ASSERT_BO_LOCKED(bp->b_bufobj);
1399 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1400 (BX_VNDIRTY|BX_VNCLEAN),
1401 ("buf_vlist_remove: Buf %p is on two lists", bp));
1402 if (bp->b_xflags & BX_VNDIRTY)
1403 bv = &bp->b_bufobj->bo_dirty;
1404 else
1405 bv = &bp->b_bufobj->bo_clean;
1406 if (bp != bv->bv_root) {
1407 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1408 KASSERT(root == bp, ("splay lookup failed in remove"));
1409 }
1410 if (bp->b_left == NULL) {
1411 root = bp->b_right;
1412 } else {
1413 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1414 root->b_right = bp->b_right;
1415 }
1416 bv->bv_root = root;
1417 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1418 bv->bv_cnt--;
1419 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1420 }
1421
1422 /*
1423 * Add the buffer to the sorted clean or dirty block list using a
1424 * splay tree algorithm.
1425 *
1426 * NOTE: xflags is passed as a constant, optimizing this inline function!
1427 */
1428 static void
1429 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1430 {
1431 struct buf *root;
1432 struct bufv *bv;
1433
1434 ASSERT_BO_LOCKED(bo);
1435 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1436 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1437 bp->b_xflags |= xflags;
1438 if (xflags & BX_VNDIRTY)
1439 bv = &bo->bo_dirty;
1440 else
1441 bv = &bo->bo_clean;
1442
1443 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1444 if (root == NULL) {
1445 bp->b_left = NULL;
1446 bp->b_right = NULL;
1447 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1448 } else if (bp->b_lblkno < root->b_lblkno ||
1449 (bp->b_lblkno == root->b_lblkno &&
1450 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1451 bp->b_left = root->b_left;
1452 bp->b_right = root;
1453 root->b_left = NULL;
1454 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1455 } else {
1456 bp->b_right = root->b_right;
1457 bp->b_left = root;
1458 root->b_right = NULL;
1459 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1460 }
1461 bv->bv_cnt++;
1462 bv->bv_root = bp;
1463 }
1464
1465 /*
1466 * Lookup a buffer using the splay tree. Note that we specifically avoid
1467 * shadow buffers used in background bitmap writes.
1468 *
1469 * This code isn't quite efficient as it could be because we are maintaining
1470 * two sorted lists and do not know which list the block resides in.
1471 *
1472 * During a "make buildworld" the desired buffer is found at one of
1473 * the roots more than 60% of the time. Thus, checking both roots
1474 * before performing either splay eliminates unnecessary splays on the
1475 * first tree splayed.
1476 */
1477 struct buf *
1478 gbincore(struct bufobj *bo, daddr_t lblkno)
1479 {
1480 struct buf *bp;
1481
1482 ASSERT_BO_LOCKED(bo);
1483 if ((bp = bo->bo_clean.bv_root) != NULL &&
1484 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1485 return (bp);
1486 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1487 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1488 return (bp);
1489 if ((bp = bo->bo_clean.bv_root) != NULL) {
1490 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1491 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1492 return (bp);
1493 }
1494 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1495 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1496 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1497 return (bp);
1498 }
1499 return (NULL);
1500 }
1501
1502 /*
1503 * Associate a buffer with a vnode.
1504 */
1505 void
1506 bgetvp(struct vnode *vp, struct buf *bp)
1507 {
1508
1509 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1510
1511 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1512 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1513 ("bgetvp: bp already attached! %p", bp));
1514
1515 ASSERT_VI_LOCKED(vp, "bgetvp");
1516 vholdl(vp);
1517 if (VFS_NEEDSGIANT(vp->v_mount) ||
1518 vp->v_bufobj.bo_flag & BO_NEEDSGIANT)
1519 bp->b_flags |= B_NEEDSGIANT;
1520 bp->b_vp = vp;
1521 bp->b_bufobj = &vp->v_bufobj;
1522 /*
1523 * Insert onto list for new vnode.
1524 */
1525 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN);
1526 }
1527
1528 /*
1529 * Disassociate a buffer from a vnode.
1530 */
1531 void
1532 brelvp(struct buf *bp)
1533 {
1534 struct bufobj *bo;
1535 struct vnode *vp;
1536
1537 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1538 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1539
1540 /*
1541 * Delete from old vnode list, if on one.
1542 */
1543 vp = bp->b_vp; /* XXX */
1544 bo = bp->b_bufobj;
1545 BO_LOCK(bo);
1546 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1547 buf_vlist_remove(bp);
1548 else
1549 panic("brelvp: Buffer %p not on queue.", bp);
1550 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1551 bo->bo_flag &= ~BO_ONWORKLST;
1552 mtx_lock(&sync_mtx);
1553 LIST_REMOVE(bo, bo_synclist);
1554 syncer_worklist_len--;
1555 mtx_unlock(&sync_mtx);
1556 }
1557 bp->b_flags &= ~B_NEEDSGIANT;
1558 bp->b_vp = NULL;
1559 bp->b_bufobj = NULL;
1560 vdropl(vp);
1561 }
1562
1563 /*
1564 * Add an item to the syncer work queue.
1565 */
1566 static void
1567 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1568 {
1569 int slot;
1570
1571 ASSERT_BO_LOCKED(bo);
1572
1573 mtx_lock(&sync_mtx);
1574 if (bo->bo_flag & BO_ONWORKLST)
1575 LIST_REMOVE(bo, bo_synclist);
1576 else {
1577 bo->bo_flag |= BO_ONWORKLST;
1578 syncer_worklist_len++;
1579 }
1580
1581 if (delay > syncer_maxdelay - 2)
1582 delay = syncer_maxdelay - 2;
1583 slot = (syncer_delayno + delay) & syncer_mask;
1584
1585 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
1586 mtx_unlock(&sync_mtx);
1587 }
1588
1589 static int
1590 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1591 {
1592 int error, len;
1593
1594 mtx_lock(&sync_mtx);
1595 len = syncer_worklist_len - sync_vnode_count;
1596 mtx_unlock(&sync_mtx);
1597 error = SYSCTL_OUT(req, &len, sizeof(len));
1598 return (error);
1599 }
1600
1601 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1602 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1603
1604 static struct proc *updateproc;
1605 static void sched_sync(void);
1606 static struct kproc_desc up_kp = {
1607 "syncer",
1608 sched_sync,
1609 &updateproc
1610 };
1611 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
1612
1613 static int
1614 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
1615 {
1616 struct vnode *vp;
1617 struct mount *mp;
1618 int vfslocked;
1619
1620 vfslocked = 0;
1621 restart:
1622 *bo = LIST_FIRST(slp);
1623 if (*bo == NULL) {
1624 VFS_UNLOCK_GIANT(vfslocked);
1625 return (0);
1626 }
1627 vp = (*bo)->__bo_vnode; /* XXX */
1628 if (VFS_NEEDSGIANT(vp->v_mount)) {
1629 if (!vfslocked) {
1630 vfslocked = 1;
1631 if (mtx_trylock(&Giant) == 0) {
1632 mtx_unlock(&sync_mtx);
1633 mtx_lock(&Giant);
1634 mtx_lock(&sync_mtx);
1635 goto restart;
1636 }
1637 }
1638 } else {
1639 VFS_UNLOCK_GIANT(vfslocked);
1640 vfslocked = 0;
1641 }
1642 if (VOP_ISLOCKED(vp, NULL) != 0) {
1643 VFS_UNLOCK_GIANT(vfslocked);
1644 return (1);
1645 }
1646 if (VI_TRYLOCK(vp) == 0) {
1647 VFS_UNLOCK_GIANT(vfslocked);
1648 return (1);
1649 }
1650 /*
1651 * We use vhold in case the vnode does not
1652 * successfully sync. vhold prevents the vnode from
1653 * going away when we unlock the sync_mtx so that
1654 * we can acquire the vnode interlock.
1655 */
1656 vholdl(vp);
1657 mtx_unlock(&sync_mtx);
1658 VI_UNLOCK(vp);
1659 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1660 vdrop(vp);
1661 VFS_UNLOCK_GIANT(vfslocked);
1662 mtx_lock(&sync_mtx);
1663 return (1);
1664 }
1665 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1666 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1667 VOP_UNLOCK(vp, 0, td);
1668 vn_finished_write(mp);
1669 VI_LOCK(vp);
1670 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
1671 /*
1672 * Put us back on the worklist. The worklist
1673 * routine will remove us from our current
1674 * position and then add us back in at a later
1675 * position.
1676 */
1677 vn_syncer_add_to_worklist(*bo, syncdelay);
1678 }
1679 vdropl(vp);
1680 VFS_UNLOCK_GIANT(vfslocked);
1681 mtx_lock(&sync_mtx);
1682 return (0);
1683 }
1684
1685 /*
1686 * System filesystem synchronizer daemon.
1687 */
1688 static void
1689 sched_sync(void)
1690 {
1691 struct synclist *next;
1692 struct synclist *slp;
1693 struct bufobj *bo;
1694 long starttime;
1695 struct thread *td = curthread;
1696 static int dummychan;
1697 int last_work_seen;
1698 int net_worklist_len;
1699 int syncer_final_iter;
1700 int first_printf;
1701 int error;
1702
1703 last_work_seen = 0;
1704 syncer_final_iter = 0;
1705 first_printf = 1;
1706 syncer_state = SYNCER_RUNNING;
1707 starttime = time_uptime;
1708 td->td_pflags |= TDP_NORUNNINGBUF;
1709
1710 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1711 SHUTDOWN_PRI_LAST);
1712
1713 mtx_lock(&sync_mtx);
1714 for (;;) {
1715 if (syncer_state == SYNCER_FINAL_DELAY &&
1716 syncer_final_iter == 0) {
1717 mtx_unlock(&sync_mtx);
1718 kthread_suspend_check(td->td_proc);
1719 mtx_lock(&sync_mtx);
1720 }
1721 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1722 if (syncer_state != SYNCER_RUNNING &&
1723 starttime != time_uptime) {
1724 if (first_printf) {
1725 printf("\nSyncing disks, vnodes remaining...");
1726 first_printf = 0;
1727 }
1728 printf("%d ", net_worklist_len);
1729 }
1730 starttime = time_uptime;
1731
1732 /*
1733 * Push files whose dirty time has expired. Be careful
1734 * of interrupt race on slp queue.
1735 *
1736 * Skip over empty worklist slots when shutting down.
1737 */
1738 do {
1739 slp = &syncer_workitem_pending[syncer_delayno];
1740 syncer_delayno += 1;
1741 if (syncer_delayno == syncer_maxdelay)
1742 syncer_delayno = 0;
1743 next = &syncer_workitem_pending[syncer_delayno];
1744 /*
1745 * If the worklist has wrapped since the
1746 * it was emptied of all but syncer vnodes,
1747 * switch to the FINAL_DELAY state and run
1748 * for one more second.
1749 */
1750 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1751 net_worklist_len == 0 &&
1752 last_work_seen == syncer_delayno) {
1753 syncer_state = SYNCER_FINAL_DELAY;
1754 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1755 }
1756 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1757 syncer_worklist_len > 0);
1758
1759 /*
1760 * Keep track of the last time there was anything
1761 * on the worklist other than syncer vnodes.
1762 * Return to the SHUTTING_DOWN state if any
1763 * new work appears.
1764 */
1765 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1766 last_work_seen = syncer_delayno;
1767 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1768 syncer_state = SYNCER_SHUTTING_DOWN;
1769 while (!LIST_EMPTY(slp)) {
1770 error = sync_vnode(slp, &bo, td);
1771 if (error == 1) {
1772 LIST_REMOVE(bo, bo_synclist);
1773 LIST_INSERT_HEAD(next, bo, bo_synclist);
1774 continue;
1775 }
1776 }
1777 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1778 syncer_final_iter--;
1779 /*
1780 * The variable rushjob allows the kernel to speed up the
1781 * processing of the filesystem syncer process. A rushjob
1782 * value of N tells the filesystem syncer to process the next
1783 * N seconds worth of work on its queue ASAP. Currently rushjob
1784 * is used by the soft update code to speed up the filesystem
1785 * syncer process when the incore state is getting so far
1786 * ahead of the disk that the kernel memory pool is being
1787 * threatened with exhaustion.
1788 */
1789 if (rushjob > 0) {
1790 rushjob -= 1;
1791 continue;
1792 }
1793 /*
1794 * Just sleep for a short period of time between
1795 * iterations when shutting down to allow some I/O
1796 * to happen.
1797 *
1798 * If it has taken us less than a second to process the
1799 * current work, then wait. Otherwise start right over
1800 * again. We can still lose time if any single round
1801 * takes more than two seconds, but it does not really
1802 * matter as we are just trying to generally pace the
1803 * filesystem activity.
1804 */
1805 if (syncer_state != SYNCER_RUNNING)
1806 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl",
1807 hz / SYNCER_SHUTDOWN_SPEEDUP);
1808 else if (time_uptime == starttime)
1809 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0);
1810 }
1811 }
1812
1813 /*
1814 * Request the syncer daemon to speed up its work.
1815 * We never push it to speed up more than half of its
1816 * normal turn time, otherwise it could take over the cpu.
1817 */
1818 int
1819 speedup_syncer(void)
1820 {
1821 struct thread *td;
1822 int ret = 0;
1823
1824 td = FIRST_THREAD_IN_PROC(updateproc);
1825 mtx_lock(&sync_mtx);
1826 if (rushjob < syncdelay / 2) {
1827 rushjob += 1;
1828 stat_rush_requests += 1;
1829 ret = 1;
1830 }
1831 mtx_unlock(&sync_mtx);
1832 sleepq_remove(td, &lbolt);
1833 return (ret);
1834 }
1835
1836 /*
1837 * Tell the syncer to speed up its work and run though its work
1838 * list several times, then tell it to shut down.
1839 */
1840 static void
1841 syncer_shutdown(void *arg, int howto)
1842 {
1843 struct thread *td;
1844
1845 if (howto & RB_NOSYNC)
1846 return;
1847 td = FIRST_THREAD_IN_PROC(updateproc);
1848 mtx_lock(&sync_mtx);
1849 syncer_state = SYNCER_SHUTTING_DOWN;
1850 rushjob = 0;
1851 mtx_unlock(&sync_mtx);
1852 sleepq_remove(td, &lbolt);
1853 kproc_shutdown(arg, howto);
1854 }
1855
1856 /*
1857 * Reassign a buffer from one vnode to another.
1858 * Used to assign file specific control information
1859 * (indirect blocks) to the vnode to which they belong.
1860 */
1861 void
1862 reassignbuf(struct buf *bp)
1863 {
1864 struct vnode *vp;
1865 struct bufobj *bo;
1866 int delay;
1867 #ifdef INVARIANTS
1868 struct bufv *bv;
1869 #endif
1870
1871 vp = bp->b_vp;
1872 bo = bp->b_bufobj;
1873 ++reassignbufcalls;
1874
1875 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1876 bp, bp->b_vp, bp->b_flags);
1877 /*
1878 * B_PAGING flagged buffers cannot be reassigned because their vp
1879 * is not fully linked in.
1880 */
1881 if (bp->b_flags & B_PAGING)
1882 panic("cannot reassign paging buffer");
1883
1884 /*
1885 * Delete from old vnode list, if on one.
1886 */
1887 VI_LOCK(vp);
1888 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1889 buf_vlist_remove(bp);
1890 else
1891 panic("reassignbuf: Buffer %p not on queue.", bp);
1892 /*
1893 * If dirty, put on list of dirty buffers; otherwise insert onto list
1894 * of clean buffers.
1895 */
1896 if (bp->b_flags & B_DELWRI) {
1897 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
1898 switch (vp->v_type) {
1899 case VDIR:
1900 delay = dirdelay;
1901 break;
1902 case VCHR:
1903 delay = metadelay;
1904 break;
1905 default:
1906 delay = filedelay;
1907 }
1908 vn_syncer_add_to_worklist(bo, delay);
1909 }
1910 buf_vlist_add(bp, bo, BX_VNDIRTY);
1911 } else {
1912 buf_vlist_add(bp, bo, BX_VNCLEAN);
1913
1914 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1915 mtx_lock(&sync_mtx);
1916 LIST_REMOVE(bo, bo_synclist);
1917 syncer_worklist_len--;
1918 mtx_unlock(&sync_mtx);
1919 bo->bo_flag &= ~BO_ONWORKLST;
1920 }
1921 }
1922 #ifdef INVARIANTS
1923 bv = &bo->bo_clean;
1924 bp = TAILQ_FIRST(&bv->bv_hd);
1925 KASSERT(bp == NULL || bp->b_bufobj == bo,
1926 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1927 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1928 KASSERT(bp == NULL || bp->b_bufobj == bo,
1929 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1930 bv = &bo->bo_dirty;
1931 bp = TAILQ_FIRST(&bv->bv_hd);
1932 KASSERT(bp == NULL || bp->b_bufobj == bo,
1933 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1934 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1935 KASSERT(bp == NULL || bp->b_bufobj == bo,
1936 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1937 #endif
1938 VI_UNLOCK(vp);
1939 }
1940
1941 /*
1942 * Increment the use and hold counts on the vnode, taking care to reference
1943 * the driver's usecount if this is a chardev. The vholdl() will remove
1944 * the vnode from the free list if it is presently free. Requires the
1945 * vnode interlock and returns with it held.
1946 */
1947 static void
1948 v_incr_usecount(struct vnode *vp)
1949 {
1950
1951 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n",
1952 vp, vp->v_holdcnt, vp->v_usecount);
1953 vp->v_usecount++;
1954 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1955 dev_lock();
1956 vp->v_rdev->si_usecount++;
1957 dev_unlock();
1958 }
1959 vholdl(vp);
1960 }
1961
1962 /*
1963 * Turn a holdcnt into a use+holdcnt such that only one call to
1964 * v_decr_usecount is needed.
1965 */
1966 static void
1967 v_upgrade_usecount(struct vnode *vp)
1968 {
1969
1970 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n",
1971 vp, vp->v_holdcnt, vp->v_usecount);
1972 vp->v_usecount++;
1973 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1974 dev_lock();
1975 vp->v_rdev->si_usecount++;
1976 dev_unlock();
1977 }
1978 }
1979
1980 /*
1981 * Decrement the vnode use and hold count along with the driver's usecount
1982 * if this is a chardev. The vdropl() below releases the vnode interlock
1983 * as it may free the vnode.
1984 */
1985 static void
1986 v_decr_usecount(struct vnode *vp)
1987 {
1988
1989 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n",
1990 vp, vp->v_holdcnt, vp->v_usecount);
1991 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1992 VNASSERT(vp->v_usecount > 0, vp,
1993 ("v_decr_usecount: negative usecount"));
1994 vp->v_usecount--;
1995 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1996 dev_lock();
1997 vp->v_rdev->si_usecount--;
1998 dev_unlock();
1999 }
2000 vdropl(vp);
2001 }
2002
2003 /*
2004 * Decrement only the use count and driver use count. This is intended to
2005 * be paired with a follow on vdropl() to release the remaining hold count.
2006 * In this way we may vgone() a vnode with a 0 usecount without risk of
2007 * having it end up on a free list because the hold count is kept above 0.
2008 */
2009 static void
2010 v_decr_useonly(struct vnode *vp)
2011 {
2012
2013 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n",
2014 vp, vp->v_holdcnt, vp->v_usecount);
2015 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2016 VNASSERT(vp->v_usecount > 0, vp,
2017 ("v_decr_useonly: negative usecount"));
2018 vp->v_usecount--;
2019 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2020 dev_lock();
2021 vp->v_rdev->si_usecount--;
2022 dev_unlock();
2023 }
2024 }
2025
2026 /*
2027 * Grab a particular vnode from the free list, increment its
2028 * reference count and lock it. The vnode lock bit is set if the
2029 * vnode is being eliminated in vgone. The process is awakened
2030 * when the transition is completed, and an error returned to
2031 * indicate that the vnode is no longer usable (possibly having
2032 * been changed to a new filesystem type).
2033 */
2034 int
2035 vget(struct vnode *vp, int flags, struct thread *td)
2036 {
2037 int oweinact;
2038 int oldflags;
2039 int error;
2040
2041 error = 0;
2042 oldflags = flags;
2043 oweinact = 0;
2044 VFS_ASSERT_GIANT(vp->v_mount);
2045 if ((flags & LK_INTERLOCK) == 0)
2046 VI_LOCK(vp);
2047 /*
2048 * If the inactive call was deferred because vput() was called
2049 * with a shared lock, we have to do it here before another thread
2050 * gets a reference to data that should be dead.
2051 */
2052 if (vp->v_iflag & VI_OWEINACT) {
2053 if (flags & LK_NOWAIT) {
2054 VI_UNLOCK(vp);
2055 return (EBUSY);
2056 }
2057 flags &= ~LK_TYPE_MASK;
2058 flags |= LK_EXCLUSIVE;
2059 oweinact = 1;
2060 }
2061 vholdl(vp);
2062 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
2063 vdrop(vp);
2064 return (error);
2065 }
2066 VI_LOCK(vp);
2067 /* Upgrade our holdcnt to a usecount. */
2068 v_upgrade_usecount(vp);
2069 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2070 panic("vget: vn_lock failed to return ENOENT\n");
2071 if (oweinact) {
2072 if (vp->v_iflag & VI_OWEINACT)
2073 vinactive(vp, td);
2074 VI_UNLOCK(vp);
2075 if ((oldflags & LK_TYPE_MASK) == 0)
2076 VOP_UNLOCK(vp, 0, td);
2077 } else
2078 VI_UNLOCK(vp);
2079 return (0);
2080 }
2081
2082 /*
2083 * Increase the reference count of a vnode.
2084 */
2085 void
2086 vref(struct vnode *vp)
2087 {
2088
2089 VI_LOCK(vp);
2090 v_incr_usecount(vp);
2091 VI_UNLOCK(vp);
2092 }
2093
2094 /*
2095 * Return reference count of a vnode.
2096 *
2097 * The results of this call are only guaranteed when some mechanism other
2098 * than the VI lock is used to stop other processes from gaining references
2099 * to the vnode. This may be the case if the caller holds the only reference.
2100 * This is also useful when stale data is acceptable as race conditions may
2101 * be accounted for by some other means.
2102 */
2103 int
2104 vrefcnt(struct vnode *vp)
2105 {
2106 int usecnt;
2107
2108 VI_LOCK(vp);
2109 usecnt = vp->v_usecount;
2110 VI_UNLOCK(vp);
2111
2112 return (usecnt);
2113 }
2114
2115
2116 /*
2117 * Vnode put/release.
2118 * If count drops to zero, call inactive routine and return to freelist.
2119 */
2120 void
2121 vrele(struct vnode *vp)
2122 {
2123 struct thread *td = curthread; /* XXX */
2124
2125 KASSERT(vp != NULL, ("vrele: null vp"));
2126 VFS_ASSERT_GIANT(vp->v_mount);
2127
2128 VI_LOCK(vp);
2129
2130 /* Skip this v_writecount check if we're going to panic below. */
2131 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2132 ("vrele: missed vn_close"));
2133
2134 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2135 vp->v_usecount == 1)) {
2136 v_decr_usecount(vp);
2137 return;
2138 }
2139 if (vp->v_usecount != 1) {
2140 #ifdef DIAGNOSTIC
2141 vprint("vrele: negative ref count", vp);
2142 #endif
2143 VI_UNLOCK(vp);
2144 panic("vrele: negative ref cnt");
2145 }
2146 /*
2147 * We want to hold the vnode until the inactive finishes to
2148 * prevent vgone() races. We drop the use count here and the
2149 * hold count below when we're done.
2150 */
2151 v_decr_useonly(vp);
2152 /*
2153 * We must call VOP_INACTIVE with the node locked. Mark
2154 * as VI_DOINGINACT to avoid recursion.
2155 */
2156 vp->v_iflag |= VI_OWEINACT;
2157 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) {
2158 VI_LOCK(vp);
2159 if (vp->v_usecount > 0)
2160 vp->v_iflag &= ~VI_OWEINACT;
2161 if (vp->v_iflag & VI_OWEINACT)
2162 vinactive(vp, td);
2163 VOP_UNLOCK(vp, 0, td);
2164 } else {
2165 VI_LOCK(vp);
2166 if (vp->v_usecount > 0)
2167 vp->v_iflag &= ~VI_OWEINACT;
2168 }
2169 vdropl(vp);
2170 }
2171
2172 /*
2173 * Release an already locked vnode. This give the same effects as
2174 * unlock+vrele(), but takes less time and avoids releasing and
2175 * re-aquiring the lock (as vrele() acquires the lock internally.)
2176 */
2177 void
2178 vput(struct vnode *vp)
2179 {
2180 struct thread *td = curthread; /* XXX */
2181 int error;
2182
2183 KASSERT(vp != NULL, ("vput: null vp"));
2184 ASSERT_VOP_LOCKED(vp, "vput");
2185 VFS_ASSERT_GIANT(vp->v_mount);
2186 VI_LOCK(vp);
2187 /* Skip this v_writecount check if we're going to panic below. */
2188 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2189 ("vput: missed vn_close"));
2190 error = 0;
2191
2192 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2193 vp->v_usecount == 1)) {
2194 VOP_UNLOCK(vp, 0, td);
2195 v_decr_usecount(vp);
2196 return;
2197 }
2198
2199 if (vp->v_usecount != 1) {
2200 #ifdef DIAGNOSTIC
2201 vprint("vput: negative ref count", vp);
2202 #endif
2203 panic("vput: negative ref cnt");
2204 }
2205 /*
2206 * We want to hold the vnode until the inactive finishes to
2207 * prevent vgone() races. We drop the use count here and the
2208 * hold count below when we're done.
2209 */
2210 v_decr_useonly(vp);
2211 vp->v_iflag |= VI_OWEINACT;
2212 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) {
2213 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td);
2214 VI_LOCK(vp);
2215 if (error) {
2216 if (vp->v_usecount > 0)
2217 vp->v_iflag &= ~VI_OWEINACT;
2218 goto done;
2219 }
2220 }
2221 if (vp->v_usecount > 0)
2222 vp->v_iflag &= ~VI_OWEINACT;
2223 if (vp->v_iflag & VI_OWEINACT)
2224 vinactive(vp, td);
2225 VOP_UNLOCK(vp, 0, td);
2226 done:
2227 vdropl(vp);
2228 }
2229
2230 /*
2231 * Somebody doesn't want the vnode recycled.
2232 */
2233 void
2234 vhold(struct vnode *vp)
2235 {
2236
2237 VI_LOCK(vp);
2238 vholdl(vp);
2239 VI_UNLOCK(vp);
2240 }
2241
2242 void
2243 vholdl(struct vnode *vp)
2244 {
2245
2246 vp->v_holdcnt++;
2247 if (VSHOULDBUSY(vp))
2248 vbusy(vp);
2249 }
2250
2251 /*
2252 * Note that there is one less who cares about this vnode. vdrop() is the
2253 * opposite of vhold().
2254 */
2255 void
2256 vdrop(struct vnode *vp)
2257 {
2258
2259 VI_LOCK(vp);
2260 vdropl(vp);
2261 }
2262
2263 /*
2264 * Drop the hold count of the vnode. If this is the last reference to
2265 * the vnode we will free it if it has been vgone'd otherwise it is
2266 * placed on the free list.
2267 */
2268 void
2269 vdropl(struct vnode *vp)
2270 {
2271
2272 ASSERT_VI_LOCKED(vp, "vdropl");
2273 if (vp->v_holdcnt <= 0)
2274 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2275 vp->v_holdcnt--;
2276 if (vp->v_holdcnt == 0) {
2277 if (vp->v_iflag & VI_DOOMED) {
2278 vdestroy(vp);
2279 return;
2280 } else
2281 vfree(vp);
2282 }
2283 VI_UNLOCK(vp);
2284 }
2285
2286 /*
2287 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2288 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2289 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2290 * failed lock upgrade.
2291 */
2292 static void
2293 vinactive(struct vnode *vp, struct thread *td)
2294 {
2295
2296 ASSERT_VOP_LOCKED(vp, "vinactive");
2297 ASSERT_VI_LOCKED(vp, "vinactive");
2298 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2299 ("vinactive: recursed on VI_DOINGINACT"));
2300 vp->v_iflag |= VI_DOINGINACT;
2301 vp->v_iflag &= ~VI_OWEINACT;
2302 VI_UNLOCK(vp);
2303 VOP_INACTIVE(vp, td);
2304 VI_LOCK(vp);
2305 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2306 ("vinactive: lost VI_DOINGINACT"));
2307 vp->v_iflag &= ~VI_DOINGINACT;
2308 }
2309
2310 /*
2311 * Remove any vnodes in the vnode table belonging to mount point mp.
2312 *
2313 * If FORCECLOSE is not specified, there should not be any active ones,
2314 * return error if any are found (nb: this is a user error, not a
2315 * system error). If FORCECLOSE is specified, detach any active vnodes
2316 * that are found.
2317 *
2318 * If WRITECLOSE is set, only flush out regular file vnodes open for
2319 * writing.
2320 *
2321 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2322 *
2323 * `rootrefs' specifies the base reference count for the root vnode
2324 * of this filesystem. The root vnode is considered busy if its
2325 * v_usecount exceeds this value. On a successful return, vflush(, td)
2326 * will call vrele() on the root vnode exactly rootrefs times.
2327 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2328 * be zero.
2329 */
2330 #ifdef DIAGNOSTIC
2331 static int busyprt = 0; /* print out busy vnodes */
2332 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
2333 #endif
2334
2335 int
2336 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td)
2337 {
2338 struct vnode *vp, *mvp, *rootvp = NULL;
2339 struct vattr vattr;
2340 int busy = 0, error;
2341
2342 CTR1(KTR_VFS, "vflush: mp %p", mp);
2343 if (rootrefs > 0) {
2344 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2345 ("vflush: bad args"));
2346 /*
2347 * Get the filesystem root vnode. We can vput() it
2348 * immediately, since with rootrefs > 0, it won't go away.
2349 */
2350 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0)
2351 return (error);
2352 vput(rootvp);
2353
2354 }
2355 MNT_ILOCK(mp);
2356 loop:
2357 MNT_VNODE_FOREACH(vp, mp, mvp) {
2358
2359 VI_LOCK(vp);
2360 vholdl(vp);
2361 MNT_IUNLOCK(mp);
2362 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td);
2363 if (error) {
2364 vdrop(vp);
2365 MNT_ILOCK(mp);
2366 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
2367 goto loop;
2368 }
2369 /*
2370 * Skip over a vnodes marked VV_SYSTEM.
2371 */
2372 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2373 VOP_UNLOCK(vp, 0, td);
2374 vdrop(vp);
2375 MNT_ILOCK(mp);
2376 continue;
2377 }
2378 /*
2379 * If WRITECLOSE is set, flush out unlinked but still open
2380 * files (even if open only for reading) and regular file
2381 * vnodes open for writing.
2382 */
2383 if (flags & WRITECLOSE) {
2384 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td);
2385 VI_LOCK(vp);
2386
2387 if ((vp->v_type == VNON ||
2388 (error == 0 && vattr.va_nlink > 0)) &&
2389 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2390 VOP_UNLOCK(vp, 0, td);
2391 vdropl(vp);
2392 MNT_ILOCK(mp);
2393 continue;
2394 }
2395 } else
2396 VI_LOCK(vp);
2397 /*
2398 * With v_usecount == 0, all we need to do is clear out the
2399 * vnode data structures and we are done.
2400 *
2401 * If FORCECLOSE is set, forcibly close the vnode.
2402 */
2403 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2404 VNASSERT(vp->v_usecount == 0 ||
2405 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2406 ("device VNODE %p is FORCECLOSED", vp));
2407 vgonel(vp);
2408 } else {
2409 busy++;
2410 #ifdef DIAGNOSTIC
2411 if (busyprt)
2412 vprint("vflush: busy vnode", vp);
2413 #endif
2414 }
2415 VOP_UNLOCK(vp, 0, td);
2416 vdropl(vp);
2417 MNT_ILOCK(mp);
2418 }
2419 MNT_IUNLOCK(mp);
2420 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2421 /*
2422 * If just the root vnode is busy, and if its refcount
2423 * is equal to `rootrefs', then go ahead and kill it.
2424 */
2425 VI_LOCK(rootvp);
2426 KASSERT(busy > 0, ("vflush: not busy"));
2427 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2428 ("vflush: usecount %d < rootrefs %d",
2429 rootvp->v_usecount, rootrefs));
2430 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2431 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td);
2432 vgone(rootvp);
2433 VOP_UNLOCK(rootvp, 0, td);
2434 busy = 0;
2435 } else
2436 VI_UNLOCK(rootvp);
2437 }
2438 if (busy)
2439 return (EBUSY);
2440 for (; rootrefs > 0; rootrefs--)
2441 vrele(rootvp);
2442 return (0);
2443 }
2444
2445 /*
2446 * Recycle an unused vnode to the front of the free list.
2447 */
2448 int
2449 vrecycle(struct vnode *vp, struct thread *td)
2450 {
2451 int recycled;
2452
2453 ASSERT_VOP_LOCKED(vp, "vrecycle");
2454 recycled = 0;
2455 VI_LOCK(vp);
2456 if (vp->v_usecount == 0) {
2457 recycled = 1;
2458 vgonel(vp);
2459 }
2460 VI_UNLOCK(vp);
2461 return (recycled);
2462 }
2463
2464 /*
2465 * Eliminate all activity associated with a vnode
2466 * in preparation for reuse.
2467 */
2468 void
2469 vgone(struct vnode *vp)
2470 {
2471 VI_LOCK(vp);
2472 vgonel(vp);
2473 VI_UNLOCK(vp);
2474 }
2475
2476 /*
2477 * vgone, with the vp interlock held.
2478 */
2479 void
2480 vgonel(struct vnode *vp)
2481 {
2482 struct thread *td;
2483 int oweinact;
2484 int active;
2485 struct mount *mp;
2486
2487 CTR1(KTR_VFS, "vgonel: vp %p", vp);
2488 ASSERT_VOP_LOCKED(vp, "vgonel");
2489 ASSERT_VI_LOCKED(vp, "vgonel");
2490 VNASSERT(vp->v_holdcnt, vp,
2491 ("vgonel: vp %p has no reference.", vp));
2492 td = curthread;
2493
2494 /*
2495 * Don't vgonel if we're already doomed.
2496 */
2497 if (vp->v_iflag & VI_DOOMED)
2498 return;
2499 vp->v_iflag |= VI_DOOMED;
2500 /*
2501 * Check to see if the vnode is in use. If so, we have to call
2502 * VOP_CLOSE() and VOP_INACTIVE().
2503 */
2504 active = vp->v_usecount;
2505 oweinact = (vp->v_iflag & VI_OWEINACT);
2506 VI_UNLOCK(vp);
2507 /*
2508 * Clean out any buffers associated with the vnode.
2509 * If the flush fails, just toss the buffers.
2510 */
2511 mp = NULL;
2512 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2513 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2514 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0)
2515 vinvalbuf(vp, 0, td, 0, 0);
2516
2517 /*
2518 * If purging an active vnode, it must be closed and
2519 * deactivated before being reclaimed.
2520 */
2521 if (active)
2522 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2523 if (oweinact || active) {
2524 VI_LOCK(vp);
2525 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2526 vinactive(vp, td);
2527 VI_UNLOCK(vp);
2528 }
2529 /*
2530 * Reclaim the vnode.
2531 */
2532 if (VOP_RECLAIM(vp, td))
2533 panic("vgone: cannot reclaim");
2534 if (mp != NULL)
2535 vn_finished_secondary_write(mp);
2536 VNASSERT(vp->v_object == NULL, vp,
2537 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2538 /*
2539 * Delete from old mount point vnode list.
2540 */
2541 delmntque(vp);
2542 cache_purge(vp);
2543 /*
2544 * Done with purge, reset to the standard lock and invalidate
2545 * the vnode.
2546 */
2547 VI_LOCK(vp);
2548 vp->v_vnlock = &vp->v_lock;
2549 vp->v_op = &dead_vnodeops;
2550 vp->v_tag = "none";
2551 vp->v_type = VBAD;
2552 }
2553
2554 /*
2555 * Calculate the total number of references to a special device.
2556 */
2557 int
2558 vcount(struct vnode *vp)
2559 {
2560 int count;
2561
2562 dev_lock();
2563 count = vp->v_rdev->si_usecount;
2564 dev_unlock();
2565 return (count);
2566 }
2567
2568 /*
2569 * Same as above, but using the struct cdev *as argument
2570 */
2571 int
2572 count_dev(struct cdev *dev)
2573 {
2574 int count;
2575
2576 dev_lock();
2577 count = dev->si_usecount;
2578 dev_unlock();
2579 return(count);
2580 }
2581
2582 /*
2583 * Print out a description of a vnode.
2584 */
2585 static char *typename[] =
2586 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2587 "VMARKER"};
2588
2589 void
2590 vn_printf(struct vnode *vp, const char *fmt, ...)
2591 {
2592 va_list ap;
2593 char buf[256], buf2[16];
2594 u_long flags;
2595
2596 va_start(ap, fmt);
2597 vprintf(fmt, ap);
2598 va_end(ap);
2599 printf("%p: ", (void *)vp);
2600 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2601 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2602 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2603 buf[0] = '\0';
2604 buf[1] = '\0';
2605 if (vp->v_vflag & VV_ROOT)
2606 strlcat(buf, "|VV_ROOT", sizeof(buf));
2607 if (vp->v_vflag & VV_ISTTY)
2608 strlcat(buf, "|VV_ISTTY", sizeof(buf));
2609 if (vp->v_vflag & VV_NOSYNC)
2610 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
2611 if (vp->v_vflag & VV_CACHEDLABEL)
2612 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
2613 if (vp->v_vflag & VV_TEXT)
2614 strlcat(buf, "|VV_TEXT", sizeof(buf));
2615 if (vp->v_vflag & VV_COPYONWRITE)
2616 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
2617 if (vp->v_vflag & VV_SYSTEM)
2618 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
2619 if (vp->v_vflag & VV_PROCDEP)
2620 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
2621 if (vp->v_vflag & VV_NOKNOTE)
2622 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
2623 if (vp->v_vflag & VV_DELETED)
2624 strlcat(buf, "|VV_DELETED", sizeof(buf));
2625 if (vp->v_vflag & VV_MD)
2626 strlcat(buf, "|VV_MD", sizeof(buf));
2627 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC |
2628 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
2629 VV_NOKNOTE | VV_DELETED | VV_MD);
2630 if (flags != 0) {
2631 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
2632 strlcat(buf, buf2, sizeof(buf));
2633 }
2634 if (vp->v_iflag & VI_MOUNT)
2635 strlcat(buf, "|VI_MOUNT", sizeof(buf));
2636 if (vp->v_iflag & VI_AGE)
2637 strlcat(buf, "|VI_AGE", sizeof(buf));
2638 if (vp->v_iflag & VI_DOOMED)
2639 strlcat(buf, "|VI_DOOMED", sizeof(buf));
2640 if (vp->v_iflag & VI_FREE)
2641 strlcat(buf, "|VI_FREE", sizeof(buf));
2642 if (vp->v_iflag & VI_OBJDIRTY)
2643 strlcat(buf, "|VI_OBJDIRTY", sizeof(buf));
2644 if (vp->v_iflag & VI_DOINGINACT)
2645 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
2646 if (vp->v_iflag & VI_OWEINACT)
2647 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
2648 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE |
2649 VI_OBJDIRTY | VI_DOINGINACT | VI_OWEINACT);
2650 if (flags != 0) {
2651 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
2652 strlcat(buf, buf2, sizeof(buf));
2653 }
2654 printf(" flags (%s)\n", buf + 1);
2655 if (mtx_owned(VI_MTX(vp)))
2656 printf(" VI_LOCKed");
2657 if (vp->v_object != NULL)
2658 printf(" v_object %p ref %d pages %d\n",
2659 vp->v_object, vp->v_object->ref_count,
2660 vp->v_object->resident_page_count);
2661 printf(" ");
2662 lockmgr_printinfo(vp->v_vnlock);
2663 printf("\n");
2664 if (vp->v_data != NULL)
2665 VOP_PRINT(vp);
2666 }
2667
2668 #ifdef DDB
2669 /*
2670 * List all of the locked vnodes in the system.
2671 * Called when debugging the kernel.
2672 */
2673 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2674 {
2675 struct mount *mp, *nmp;
2676 struct vnode *vp;
2677
2678 /*
2679 * Note: because this is DDB, we can't obey the locking semantics
2680 * for these structures, which means we could catch an inconsistent
2681 * state and dereference a nasty pointer. Not much to be done
2682 * about that.
2683 */
2684 printf("Locked vnodes\n");
2685 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2686 nmp = TAILQ_NEXT(mp, mnt_list);
2687 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2688 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL))
2689 vprint("", vp);
2690 }
2691 nmp = TAILQ_NEXT(mp, mnt_list);
2692 }
2693 }
2694
2695 /*
2696 * Show details about the given vnode.
2697 */
2698 DB_SHOW_COMMAND(vnode, db_show_vnode)
2699 {
2700 struct vnode *vp;
2701
2702 if (!have_addr)
2703 return;
2704 vp = (struct vnode *)addr;
2705 vn_printf(vp, "vnode ");
2706 }
2707 #endif /* DDB */
2708
2709 /*
2710 * Fill in a struct xvfsconf based on a struct vfsconf.
2711 */
2712 static void
2713 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
2714 {
2715
2716 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
2717 xvfsp->vfc_typenum = vfsp->vfc_typenum;
2718 xvfsp->vfc_refcount = vfsp->vfc_refcount;
2719 xvfsp->vfc_flags = vfsp->vfc_flags;
2720 /*
2721 * These are unused in userland, we keep them
2722 * to not break binary compatibility.
2723 */
2724 xvfsp->vfc_vfsops = NULL;
2725 xvfsp->vfc_next = NULL;
2726 }
2727
2728 /*
2729 * Top level filesystem related information gathering.
2730 */
2731 static int
2732 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
2733 {
2734 struct vfsconf *vfsp;
2735 struct xvfsconf xvfsp;
2736 int error;
2737
2738 error = 0;
2739 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2740 bzero(&xvfsp, sizeof(xvfsp));
2741 vfsconf2x(vfsp, &xvfsp);
2742 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
2743 if (error)
2744 break;
2745 }
2746 return (error);
2747 }
2748
2749 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist,
2750 "S,xvfsconf", "List of all configured filesystems");
2751
2752 #ifndef BURN_BRIDGES
2753 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
2754
2755 static int
2756 vfs_sysctl(SYSCTL_HANDLER_ARGS)
2757 {
2758 int *name = (int *)arg1 - 1; /* XXX */
2759 u_int namelen = arg2 + 1; /* XXX */
2760 struct vfsconf *vfsp;
2761 struct xvfsconf xvfsp;
2762
2763 printf("WARNING: userland calling deprecated sysctl, "
2764 "please rebuild world\n");
2765
2766 #if 1 || defined(COMPAT_PRELITE2)
2767 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
2768 if (namelen == 1)
2769 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
2770 #endif
2771
2772 switch (name[1]) {
2773 case VFS_MAXTYPENUM:
2774 if (namelen != 2)
2775 return (ENOTDIR);
2776 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
2777 case VFS_CONF:
2778 if (namelen != 3)
2779 return (ENOTDIR); /* overloaded */
2780 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
2781 if (vfsp->vfc_typenum == name[2])
2782 break;
2783 if (vfsp == NULL)
2784 return (EOPNOTSUPP);
2785 bzero(&xvfsp, sizeof(xvfsp));
2786 vfsconf2x(vfsp, &xvfsp);
2787 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
2788 }
2789 return (EOPNOTSUPP);
2790 }
2791
2792 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
2793 vfs_sysctl, "Generic filesystem");
2794
2795 #if 1 || defined(COMPAT_PRELITE2)
2796
2797 static int
2798 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
2799 {
2800 int error;
2801 struct vfsconf *vfsp;
2802 struct ovfsconf ovfs;
2803
2804 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2805 bzero(&ovfs, sizeof(ovfs));
2806 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
2807 strcpy(ovfs.vfc_name, vfsp->vfc_name);
2808 ovfs.vfc_index = vfsp->vfc_typenum;
2809 ovfs.vfc_refcount = vfsp->vfc_refcount;
2810 ovfs.vfc_flags = vfsp->vfc_flags;
2811 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
2812 if (error)
2813 return error;
2814 }
2815 return 0;
2816 }
2817
2818 #endif /* 1 || COMPAT_PRELITE2 */
2819 #endif /* !BURN_BRIDGES */
2820
2821 #define KINFO_VNODESLOP 10
2822 #ifdef notyet
2823 /*
2824 * Dump vnode list (via sysctl).
2825 */
2826 /* ARGSUSED */
2827 static int
2828 sysctl_vnode(SYSCTL_HANDLER_ARGS)
2829 {
2830 struct xvnode *xvn;
2831 struct thread *td = req->td;
2832 struct mount *mp;
2833 struct vnode *vp;
2834 int error, len, n;
2835
2836 /*
2837 * Stale numvnodes access is not fatal here.
2838 */
2839 req->lock = 0;
2840 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
2841 if (!req->oldptr)
2842 /* Make an estimate */
2843 return (SYSCTL_OUT(req, 0, len));
2844
2845 error = sysctl_wire_old_buffer(req, 0);
2846 if (error != 0)
2847 return (error);
2848 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
2849 n = 0;
2850 mtx_lock(&mountlist_mtx);
2851 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2852 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td))
2853 continue;
2854 MNT_ILOCK(mp);
2855 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2856 if (n == len)
2857 break;
2858 vref(vp);
2859 xvn[n].xv_size = sizeof *xvn;
2860 xvn[n].xv_vnode = vp;
2861 xvn[n].xv_id = 0; /* XXX compat */
2862 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
2863 XV_COPY(usecount);
2864 XV_COPY(writecount);
2865 XV_COPY(holdcnt);
2866 XV_COPY(mount);
2867 XV_COPY(numoutput);
2868 XV_COPY(type);
2869 #undef XV_COPY
2870 xvn[n].xv_flag = vp->v_vflag;
2871
2872 switch (vp->v_type) {
2873 case VREG:
2874 case VDIR:
2875 case VLNK:
2876 break;
2877 case VBLK:
2878 case VCHR:
2879 if (vp->v_rdev == NULL) {
2880 vrele(vp);
2881 continue;
2882 }
2883 xvn[n].xv_dev = dev2udev(vp->v_rdev);
2884 break;
2885 case VSOCK:
2886 xvn[n].xv_socket = vp->v_socket;
2887 break;
2888 case VFIFO:
2889 xvn[n].xv_fifo = vp->v_fifoinfo;
2890 break;
2891 case VNON:
2892 case VBAD:
2893 default:
2894 /* shouldn't happen? */
2895 vrele(vp);
2896 continue;
2897 }
2898 vrele(vp);
2899 ++n;
2900 }
2901 MNT_IUNLOCK(mp);
2902 mtx_lock(&mountlist_mtx);
2903 vfs_unbusy(mp, td);
2904 if (n == len)
2905 break;
2906 }
2907 mtx_unlock(&mountlist_mtx);
2908
2909 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
2910 free(xvn, M_TEMP);
2911 return (error);
2912 }
2913
2914 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
2915 0, 0, sysctl_vnode, "S,xvnode", "");
2916 #endif
2917
2918 /*
2919 * Unmount all filesystems. The list is traversed in reverse order
2920 * of mounting to avoid dependencies.
2921 */
2922 void
2923 vfs_unmountall(void)
2924 {
2925 struct mount *mp;
2926 struct thread *td;
2927 int error;
2928
2929 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
2930 td = curthread;
2931 /*
2932 * Since this only runs when rebooting, it is not interlocked.
2933 */
2934 while(!TAILQ_EMPTY(&mountlist)) {
2935 mp = TAILQ_LAST(&mountlist, mntlist);
2936 error = dounmount(mp, MNT_FORCE, td);
2937 if (error) {
2938 TAILQ_REMOVE(&mountlist, mp, mnt_list);
2939 /*
2940 * XXX: Due to the way in which we mount the root
2941 * file system off of devfs, devfs will generate a
2942 * "busy" warning when we try to unmount it before
2943 * the root. Don't print a warning as a result in
2944 * order to avoid false positive errors that may
2945 * cause needless upset.
2946 */
2947 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
2948 printf("unmount of %s failed (",
2949 mp->mnt_stat.f_mntonname);
2950 if (error == EBUSY)
2951 printf("BUSY)\n");
2952 else
2953 printf("%d)\n", error);
2954 }
2955 } else {
2956 /* The unmount has removed mp from the mountlist */
2957 }
2958 }
2959 }
2960
2961 /*
2962 * perform msync on all vnodes under a mount point
2963 * the mount point must be locked.
2964 */
2965 void
2966 vfs_msync(struct mount *mp, int flags)
2967 {
2968 struct vnode *vp, *mvp;
2969 struct vm_object *obj;
2970
2971 MNT_ILOCK(mp);
2972 MNT_VNODE_FOREACH(vp, mp, mvp) {
2973 VI_LOCK(vp);
2974 if ((vp->v_iflag & VI_OBJDIRTY) &&
2975 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
2976 MNT_IUNLOCK(mp);
2977 if (!vget(vp,
2978 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
2979 curthread)) {
2980 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
2981 vput(vp);
2982 MNT_ILOCK(mp);
2983 continue;
2984 }
2985
2986 obj = vp->v_object;
2987 if (obj != NULL) {
2988 VM_OBJECT_LOCK(obj);
2989 vm_object_page_clean(obj, 0, 0,
2990 flags == MNT_WAIT ?
2991 OBJPC_SYNC : OBJPC_NOSYNC);
2992 VM_OBJECT_UNLOCK(obj);
2993 }
2994 vput(vp);
2995 }
2996 MNT_ILOCK(mp);
2997 } else
2998 VI_UNLOCK(vp);
2999 }
3000 MNT_IUNLOCK(mp);
3001 }
3002
3003 /*
3004 * Mark a vnode as free, putting it up for recycling.
3005 */
3006 static void
3007 vfree(struct vnode *vp)
3008 {
3009
3010 CTR1(KTR_VFS, "vfree vp %p", vp);
3011 ASSERT_VI_LOCKED(vp, "vfree");
3012 mtx_lock(&vnode_free_list_mtx);
3013 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed."));
3014 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free"));
3015 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't"));
3016 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp,
3017 ("vfree: Freeing doomed vnode"));
3018 if (vp->v_iflag & VI_AGE) {
3019 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
3020 } else {
3021 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
3022 }
3023 freevnodes++;
3024 vp->v_iflag &= ~VI_AGE;
3025 vp->v_iflag |= VI_FREE;
3026 mtx_unlock(&vnode_free_list_mtx);
3027 }
3028
3029 /*
3030 * Opposite of vfree() - mark a vnode as in use.
3031 */
3032 static void
3033 vbusy(struct vnode *vp)
3034 {
3035 CTR1(KTR_VFS, "vbusy vp %p", vp);
3036 ASSERT_VI_LOCKED(vp, "vbusy");
3037 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
3038 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed."));
3039
3040 mtx_lock(&vnode_free_list_mtx);
3041 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
3042 freevnodes--;
3043 vp->v_iflag &= ~(VI_FREE|VI_AGE);
3044 mtx_unlock(&vnode_free_list_mtx);
3045 }
3046
3047 /*
3048 * Initalize per-vnode helper structure to hold poll-related state.
3049 */
3050 void
3051 v_addpollinfo(struct vnode *vp)
3052 {
3053 struct vpollinfo *vi;
3054
3055 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
3056 if (vp->v_pollinfo != NULL) {
3057 uma_zfree(vnodepoll_zone, vi);
3058 return;
3059 }
3060 vp->v_pollinfo = vi;
3061 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
3062 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock,
3063 vfs_knlunlock, vfs_knllocked);
3064 }
3065
3066 /*
3067 * Record a process's interest in events which might happen to
3068 * a vnode. Because poll uses the historic select-style interface
3069 * internally, this routine serves as both the ``check for any
3070 * pending events'' and the ``record my interest in future events''
3071 * functions. (These are done together, while the lock is held,
3072 * to avoid race conditions.)
3073 */
3074 int
3075 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3076 {
3077
3078 if (vp->v_pollinfo == NULL)
3079 v_addpollinfo(vp);
3080 mtx_lock(&vp->v_pollinfo->vpi_lock);
3081 if (vp->v_pollinfo->vpi_revents & events) {
3082 /*
3083 * This leaves events we are not interested
3084 * in available for the other process which
3085 * which presumably had requested them
3086 * (otherwise they would never have been
3087 * recorded).
3088 */
3089 events &= vp->v_pollinfo->vpi_revents;
3090 vp->v_pollinfo->vpi_revents &= ~events;
3091
3092 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3093 return events;
3094 }
3095 vp->v_pollinfo->vpi_events |= events;
3096 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3097 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3098 return 0;
3099 }
3100
3101 /*
3102 * Routine to create and manage a filesystem syncer vnode.
3103 */
3104 #define sync_close ((int (*)(struct vop_close_args *))nullop)
3105 static int sync_fsync(struct vop_fsync_args *);
3106 static int sync_inactive(struct vop_inactive_args *);
3107 static int sync_reclaim(struct vop_reclaim_args *);
3108
3109 static struct vop_vector sync_vnodeops = {
3110 .vop_bypass = VOP_EOPNOTSUPP,
3111 .vop_close = sync_close, /* close */
3112 .vop_fsync = sync_fsync, /* fsync */
3113 .vop_inactive = sync_inactive, /* inactive */
3114 .vop_reclaim = sync_reclaim, /* reclaim */
3115 .vop_lock1 = vop_stdlock, /* lock */
3116 .vop_unlock = vop_stdunlock, /* unlock */
3117 .vop_islocked = vop_stdislocked, /* islocked */
3118 };
3119
3120 /*
3121 * Create a new filesystem syncer vnode for the specified mount point.
3122 */
3123 int
3124 vfs_allocate_syncvnode(struct mount *mp)
3125 {
3126 struct vnode *vp;
3127 static long start, incr, next;
3128 int error;
3129
3130 /* Allocate a new vnode */
3131 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) {
3132 mp->mnt_syncer = NULL;
3133 return (error);
3134 }
3135 vp->v_type = VNON;
3136 error = insmntque(vp, mp);
3137 if (error != 0)
3138 panic("vfs_allocate_syncvnode: insmntque failed");
3139 /*
3140 * Place the vnode onto the syncer worklist. We attempt to
3141 * scatter them about on the list so that they will go off
3142 * at evenly distributed times even if all the filesystems
3143 * are mounted at once.
3144 */
3145 next += incr;
3146 if (next == 0 || next > syncer_maxdelay) {
3147 start /= 2;
3148 incr /= 2;
3149 if (start == 0) {
3150 start = syncer_maxdelay / 2;
3151 incr = syncer_maxdelay;
3152 }
3153 next = start;
3154 }
3155 VI_LOCK(vp);
3156 vn_syncer_add_to_worklist(&vp->v_bufobj,
3157 syncdelay > 0 ? next % syncdelay : 0);
3158 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
3159 mtx_lock(&sync_mtx);
3160 sync_vnode_count++;
3161 mtx_unlock(&sync_mtx);
3162 VI_UNLOCK(vp);
3163 mp->mnt_syncer = vp;
3164 return (0);
3165 }
3166
3167 /*
3168 * Do a lazy sync of the filesystem.
3169 */
3170 static int
3171 sync_fsync(struct vop_fsync_args *ap)
3172 {
3173 struct vnode *syncvp = ap->a_vp;
3174 struct mount *mp = syncvp->v_mount;
3175 struct thread *td = ap->a_td;
3176 int error;
3177 struct bufobj *bo;
3178
3179 /*
3180 * We only need to do something if this is a lazy evaluation.
3181 */
3182 if (ap->a_waitfor != MNT_LAZY)
3183 return (0);
3184
3185 /*
3186 * Move ourselves to the back of the sync list.
3187 */
3188 bo = &syncvp->v_bufobj;
3189 BO_LOCK(bo);
3190 vn_syncer_add_to_worklist(bo, syncdelay);
3191 BO_UNLOCK(bo);
3192
3193 /*
3194 * Walk the list of vnodes pushing all that are dirty and
3195 * not already on the sync list.
3196 */
3197 mtx_lock(&mountlist_mtx);
3198 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) {
3199 mtx_unlock(&mountlist_mtx);
3200 return (0);
3201 }
3202 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
3203 vfs_unbusy(mp, td);
3204 return (0);
3205 }
3206 MNT_ILOCK(mp);
3207 mp->mnt_noasync++;
3208 mp->mnt_kern_flag &= ~MNTK_ASYNC;
3209 MNT_IUNLOCK(mp);
3210 vfs_msync(mp, MNT_NOWAIT);
3211 error = VFS_SYNC(mp, MNT_LAZY, td);
3212 MNT_ILOCK(mp);
3213 mp->mnt_noasync--;
3214 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
3215 mp->mnt_kern_flag |= MNTK_ASYNC;
3216 MNT_IUNLOCK(mp);
3217 vn_finished_write(mp);
3218 vfs_unbusy(mp, td);
3219 return (error);
3220 }
3221
3222 /*
3223 * The syncer vnode is no referenced.
3224 */
3225 static int
3226 sync_inactive(struct vop_inactive_args *ap)
3227 {
3228
3229 vgone(ap->a_vp);
3230 return (0);
3231 }
3232
3233 /*
3234 * The syncer vnode is no longer needed and is being decommissioned.
3235 *
3236 * Modifications to the worklist must be protected by sync_mtx.
3237 */
3238 static int
3239 sync_reclaim(struct vop_reclaim_args *ap)
3240 {
3241 struct vnode *vp = ap->a_vp;
3242 struct bufobj *bo;
3243
3244 VI_LOCK(vp);
3245 bo = &vp->v_bufobj;
3246 vp->v_mount->mnt_syncer = NULL;
3247 if (bo->bo_flag & BO_ONWORKLST) {
3248 mtx_lock(&sync_mtx);
3249 LIST_REMOVE(bo, bo_synclist);
3250 syncer_worklist_len--;
3251 sync_vnode_count--;
3252 mtx_unlock(&sync_mtx);
3253 bo->bo_flag &= ~BO_ONWORKLST;
3254 }
3255 VI_UNLOCK(vp);
3256
3257 return (0);
3258 }
3259
3260 /*
3261 * Check if vnode represents a disk device
3262 */
3263 int
3264 vn_isdisk(struct vnode *vp, int *errp)
3265 {
3266 int error;
3267
3268 error = 0;
3269 dev_lock();
3270 if (vp->v_type != VCHR)
3271 error = ENOTBLK;
3272 else if (vp->v_rdev == NULL)
3273 error = ENXIO;
3274 else if (vp->v_rdev->si_devsw == NULL)
3275 error = ENXIO;
3276 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
3277 error = ENOTBLK;
3278 dev_unlock();
3279 if (errp != NULL)
3280 *errp = error;
3281 return (error == 0);
3282 }
3283
3284 /*
3285 * Common filesystem object access control check routine. Accepts a
3286 * vnode's type, "mode", uid and gid, requested access mode, credentials,
3287 * and optional call-by-reference privused argument allowing vaccess()
3288 * to indicate to the caller whether privilege was used to satisfy the
3289 * request (obsoleted). Returns 0 on success, or an errno on failure.
3290 *
3291 * The ifdef'd CAPABILITIES version is here for reference, but is not
3292 * actually used.
3293 */
3294 int
3295 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
3296 mode_t acc_mode, struct ucred *cred, int *privused)
3297 {
3298 mode_t dac_granted;
3299 mode_t priv_granted;
3300
3301 /*
3302 * Look for a normal, non-privileged way to access the file/directory
3303 * as requested. If it exists, go with that.
3304 */
3305
3306 if (privused != NULL)
3307 *privused = 0;
3308
3309 dac_granted = 0;
3310
3311 /* Check the owner. */
3312 if (cred->cr_uid == file_uid) {
3313 dac_granted |= VADMIN;
3314 if (file_mode & S_IXUSR)
3315 dac_granted |= VEXEC;
3316 if (file_mode & S_IRUSR)
3317 dac_granted |= VREAD;
3318 if (file_mode & S_IWUSR)
3319 dac_granted |= (VWRITE | VAPPEND);
3320
3321 if ((acc_mode & dac_granted) == acc_mode)
3322 return (0);
3323
3324 goto privcheck;
3325 }
3326
3327 /* Otherwise, check the groups (first match) */
3328 if (groupmember(file_gid, cred)) {
3329 if (file_mode & S_IXGRP)
3330 dac_granted |= VEXEC;
3331 if (file_mode & S_IRGRP)
3332 dac_granted |= VREAD;
3333 if (file_mode & S_IWGRP)
3334 dac_granted |= (VWRITE | VAPPEND);
3335
3336 if ((acc_mode & dac_granted) == acc_mode)
3337 return (0);
3338
3339 goto privcheck;
3340 }
3341
3342 /* Otherwise, check everyone else. */
3343 if (file_mode & S_IXOTH)
3344 dac_granted |= VEXEC;
3345 if (file_mode & S_IROTH)
3346 dac_granted |= VREAD;
3347 if (file_mode & S_IWOTH)
3348 dac_granted |= (VWRITE | VAPPEND);
3349 if ((acc_mode & dac_granted) == acc_mode)
3350 return (0);
3351
3352 privcheck:
3353 /*
3354 * Build a privilege mask to determine if the set of privileges
3355 * satisfies the requirements when combined with the granted mask
3356 * from above. For each privilege, if the privilege is required,
3357 * bitwise or the request type onto the priv_granted mask.
3358 */
3359 priv_granted = 0;
3360
3361 if (type == VDIR) {
3362 /*
3363 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
3364 * requests, instead of PRIV_VFS_EXEC.
3365 */
3366 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3367 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
3368 priv_granted |= VEXEC;
3369 } else {
3370 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3371 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
3372 priv_granted |= VEXEC;
3373 }
3374
3375 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) &&
3376 !priv_check_cred(cred, PRIV_VFS_READ, 0))
3377 priv_granted |= VREAD;
3378
3379 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
3380 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
3381 priv_granted |= (VWRITE | VAPPEND);
3382
3383 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
3384 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
3385 priv_granted |= VADMIN;
3386
3387 if ((acc_mode & (priv_granted | dac_granted)) == acc_mode) {
3388 /* XXX audit: privilege used */
3389 if (privused != NULL)
3390 *privused = 1;
3391 return (0);
3392 }
3393
3394 return ((acc_mode & VADMIN) ? EPERM : EACCES);
3395 }
3396
3397 /*
3398 * Credential check based on process requesting service, and per-attribute
3399 * permissions.
3400 */
3401 int
3402 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
3403 struct thread *td, int access)
3404 {
3405
3406 /*
3407 * Kernel-invoked always succeeds.
3408 */
3409 if (cred == NOCRED)
3410 return (0);
3411
3412 /*
3413 * Do not allow privileged processes in jail to directly manipulate
3414 * system attributes.
3415 */
3416 switch (attrnamespace) {
3417 case EXTATTR_NAMESPACE_SYSTEM:
3418 /* Potentially should be: return (EPERM); */
3419 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
3420 case EXTATTR_NAMESPACE_USER:
3421 return (VOP_ACCESS(vp, access, cred, td));
3422 default:
3423 return (EPERM);
3424 }
3425 }
3426
3427 #ifdef DEBUG_VFS_LOCKS
3428 /*
3429 * This only exists to supress warnings from unlocked specfs accesses. It is
3430 * no longer ok to have an unlocked VFS.
3431 */
3432 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD)
3433
3434 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
3435 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, "");
3436
3437 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
3438 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, "");
3439
3440 int vfs_badlock_print = 1; /* Print lock violations. */
3441 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, "");
3442
3443 #ifdef KDB
3444 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
3445 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, "");
3446 #endif
3447
3448 static void
3449 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
3450 {
3451
3452 #ifdef KDB
3453 if (vfs_badlock_backtrace)
3454 kdb_backtrace();
3455 #endif
3456 if (vfs_badlock_print)
3457 printf("%s: %p %s\n", str, (void *)vp, msg);
3458 if (vfs_badlock_ddb)
3459 kdb_enter("lock violation");
3460 }
3461
3462 void
3463 assert_vi_locked(struct vnode *vp, const char *str)
3464 {
3465
3466 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
3467 vfs_badlock("interlock is not locked but should be", str, vp);
3468 }
3469
3470 void
3471 assert_vi_unlocked(struct vnode *vp, const char *str)
3472 {
3473
3474 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
3475 vfs_badlock("interlock is locked but should not be", str, vp);
3476 }
3477
3478 void
3479 assert_vop_locked(struct vnode *vp, const char *str)
3480 {
3481
3482 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0)
3483 vfs_badlock("is not locked but should be", str, vp);
3484 }
3485
3486 void
3487 assert_vop_unlocked(struct vnode *vp, const char *str)
3488 {
3489
3490 if (vp && !IGNORE_LOCK(vp) &&
3491 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE)
3492 vfs_badlock("is locked but should not be", str, vp);
3493 }
3494
3495 void
3496 assert_vop_elocked(struct vnode *vp, const char *str)
3497 {
3498
3499 if (vp && !IGNORE_LOCK(vp) &&
3500 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE)
3501 vfs_badlock("is not exclusive locked but should be", str, vp);
3502 }
3503
3504 #if 0
3505 void
3506 assert_vop_elocked_other(struct vnode *vp, const char *str)
3507 {
3508
3509 if (vp && !IGNORE_LOCK(vp) &&
3510 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER)
3511 vfs_badlock("is not exclusive locked by another thread",
3512 str, vp);
3513 }
3514
3515 void
3516 assert_vop_slocked(struct vnode *vp, const char *str)
3517 {
3518
3519 if (vp && !IGNORE_LOCK(vp) &&
3520 VOP_ISLOCKED(vp, curthread) != LK_SHARED)
3521 vfs_badlock("is not locked shared but should be", str, vp);
3522 }
3523 #endif /* 0 */
3524 #endif /* DEBUG_VFS_LOCKS */
3525
3526 void
3527 vop_rename_pre(void *ap)
3528 {
3529 struct vop_rename_args *a = ap;
3530
3531 #ifdef DEBUG_VFS_LOCKS
3532 if (a->a_tvp)
3533 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
3534 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
3535 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
3536 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
3537
3538 /* Check the source (from). */
3539 if (a->a_tdvp != a->a_fdvp && a->a_tvp != a->a_fdvp)
3540 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
3541 if (a->a_tvp != a->a_fvp)
3542 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
3543
3544 /* Check the target. */
3545 if (a->a_tvp)
3546 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
3547 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
3548 #endif
3549 if (a->a_tdvp != a->a_fdvp)
3550 vhold(a->a_fdvp);
3551 if (a->a_tvp != a->a_fvp)
3552 vhold(a->a_fvp);
3553 vhold(a->a_tdvp);
3554 if (a->a_tvp)
3555 vhold(a->a_tvp);
3556 }
3557
3558 void
3559 vop_strategy_pre(void *ap)
3560 {
3561 #ifdef DEBUG_VFS_LOCKS
3562 struct vop_strategy_args *a;
3563 struct buf *bp;
3564
3565 a = ap;
3566 bp = a->a_bp;
3567
3568 /*
3569 * Cluster ops lock their component buffers but not the IO container.
3570 */
3571 if ((bp->b_flags & B_CLUSTER) != 0)
3572 return;
3573
3574 if (BUF_REFCNT(bp) < 1) {
3575 if (vfs_badlock_print)
3576 printf(
3577 "VOP_STRATEGY: bp is not locked but should be\n");
3578 if (vfs_badlock_ddb)
3579 kdb_enter("lock violation");
3580 }
3581 #endif
3582 }
3583
3584 void
3585 vop_lookup_pre(void *ap)
3586 {
3587 #ifdef DEBUG_VFS_LOCKS
3588 struct vop_lookup_args *a;
3589 struct vnode *dvp;
3590
3591 a = ap;
3592 dvp = a->a_dvp;
3593 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3594 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3595 #endif
3596 }
3597
3598 void
3599 vop_lookup_post(void *ap, int rc)
3600 {
3601 #ifdef DEBUG_VFS_LOCKS
3602 struct vop_lookup_args *a;
3603 struct vnode *dvp;
3604 struct vnode *vp;
3605
3606 a = ap;
3607 dvp = a->a_dvp;
3608 vp = *(a->a_vpp);
3609
3610 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3611 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3612
3613 if (!rc)
3614 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)");
3615 #endif
3616 }
3617
3618 void
3619 vop_lock_pre(void *ap)
3620 {
3621 #ifdef DEBUG_VFS_LOCKS
3622 struct vop_lock1_args *a = ap;
3623
3624 if ((a->a_flags & LK_INTERLOCK) == 0)
3625 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3626 else
3627 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
3628 #endif
3629 }
3630
3631 void
3632 vop_lock_post(void *ap, int rc)
3633 {
3634 #ifdef DEBUG_VFS_LOCKS
3635 struct vop_lock1_args *a = ap;
3636
3637 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3638 if (rc == 0)
3639 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
3640 #endif
3641 }
3642
3643 void
3644 vop_unlock_pre(void *ap)
3645 {
3646 #ifdef DEBUG_VFS_LOCKS
3647 struct vop_unlock_args *a = ap;
3648
3649 if (a->a_flags & LK_INTERLOCK)
3650 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
3651 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
3652 #endif
3653 }
3654
3655 void
3656 vop_unlock_post(void *ap, int rc)
3657 {
3658 #ifdef DEBUG_VFS_LOCKS
3659 struct vop_unlock_args *a = ap;
3660
3661 if (a->a_flags & LK_INTERLOCK)
3662 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
3663 #endif
3664 }
3665
3666 void
3667 vop_create_post(void *ap, int rc)
3668 {
3669 struct vop_create_args *a = ap;
3670
3671 if (!rc)
3672 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3673 }
3674
3675 void
3676 vop_link_post(void *ap, int rc)
3677 {
3678 struct vop_link_args *a = ap;
3679
3680 if (!rc) {
3681 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
3682 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
3683 }
3684 }
3685
3686 void
3687 vop_mkdir_post(void *ap, int rc)
3688 {
3689 struct vop_mkdir_args *a = ap;
3690
3691 if (!rc)
3692 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
3693 }
3694
3695 void
3696 vop_mknod_post(void *ap, int rc)
3697 {
3698 struct vop_mknod_args *a = ap;
3699
3700 if (!rc)
3701 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3702 }
3703
3704 void
3705 vop_remove_post(void *ap, int rc)
3706 {
3707 struct vop_remove_args *a = ap;
3708
3709 if (!rc) {
3710 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3711 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
3712 }
3713 }
3714
3715 void
3716 vop_rename_post(void *ap, int rc)
3717 {
3718 struct vop_rename_args *a = ap;
3719
3720 if (!rc) {
3721 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE);
3722 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE);
3723 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
3724 if (a->a_tvp)
3725 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
3726 }
3727 if (a->a_tdvp != a->a_fdvp)
3728 vdrop(a->a_fdvp);
3729 if (a->a_tvp != a->a_fvp)
3730 vdrop(a->a_fvp);
3731 vdrop(a->a_tdvp);
3732 if (a->a_tvp)
3733 vdrop(a->a_tvp);
3734 }
3735
3736 void
3737 vop_rmdir_post(void *ap, int rc)
3738 {
3739 struct vop_rmdir_args *a = ap;
3740
3741 if (!rc) {
3742 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
3743 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
3744 }
3745 }
3746
3747 void
3748 vop_setattr_post(void *ap, int rc)
3749 {
3750 struct vop_setattr_args *a = ap;
3751
3752 if (!rc)
3753 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
3754 }
3755
3756 void
3757 vop_symlink_post(void *ap, int rc)
3758 {
3759 struct vop_symlink_args *a = ap;
3760
3761 if (!rc)
3762 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3763 }
3764
3765 static struct knlist fs_knlist;
3766
3767 static void
3768 vfs_event_init(void *arg)
3769 {
3770 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL);
3771 }
3772 /* XXX - correct order? */
3773 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
3774
3775 void
3776 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused)
3777 {
3778
3779 KNOTE_UNLOCKED(&fs_knlist, event);
3780 }
3781
3782 static int filt_fsattach(struct knote *kn);
3783 static void filt_fsdetach(struct knote *kn);
3784 static int filt_fsevent(struct knote *kn, long hint);
3785
3786 struct filterops fs_filtops =
3787 { 0, filt_fsattach, filt_fsdetach, filt_fsevent };
3788
3789 static int
3790 filt_fsattach(struct knote *kn)
3791 {
3792
3793 kn->kn_flags |= EV_CLEAR;
3794 knlist_add(&fs_knlist, kn, 0);
3795 return (0);
3796 }
3797
3798 static void
3799 filt_fsdetach(struct knote *kn)
3800 {
3801
3802 knlist_remove(&fs_knlist, kn, 0);
3803 }
3804
3805 static int
3806 filt_fsevent(struct knote *kn, long hint)
3807 {
3808
3809 kn->kn_fflags |= hint;
3810 return (kn->kn_fflags != 0);
3811 }
3812
3813 static int
3814 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
3815 {
3816 struct vfsidctl vc;
3817 int error;
3818 struct mount *mp;
3819
3820 error = SYSCTL_IN(req, &vc, sizeof(vc));
3821 if (error)
3822 return (error);
3823 if (vc.vc_vers != VFS_CTL_VERS1)
3824 return (EINVAL);
3825 mp = vfs_getvfs(&vc.vc_fsid);
3826 if (mp == NULL)
3827 return (ENOENT);
3828 /* ensure that a specific sysctl goes to the right filesystem. */
3829 if (strcmp(vc.vc_fstypename, "*") != 0 &&
3830 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
3831 vfs_rel(mp);
3832 return (EINVAL);
3833 }
3834 VCTLTOREQ(&vc, req);
3835 error = VFS_SYSCTL(mp, vc.vc_op, req);
3836 vfs_rel(mp);
3837 return (error);
3838 }
3839
3840 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "",
3841 "Sysctl by fsid");
3842
3843 /*
3844 * Function to initialize a va_filerev field sensibly.
3845 * XXX: Wouldn't a random number make a lot more sense ??
3846 */
3847 u_quad_t
3848 init_va_filerev(void)
3849 {
3850 struct bintime bt;
3851
3852 getbinuptime(&bt);
3853 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
3854 }
3855
3856 static int filt_vfsread(struct knote *kn, long hint);
3857 static int filt_vfswrite(struct knote *kn, long hint);
3858 static int filt_vfsvnode(struct knote *kn, long hint);
3859 static void filt_vfsdetach(struct knote *kn);
3860 static struct filterops vfsread_filtops =
3861 { 1, NULL, filt_vfsdetach, filt_vfsread };
3862 static struct filterops vfswrite_filtops =
3863 { 1, NULL, filt_vfsdetach, filt_vfswrite };
3864 static struct filterops vfsvnode_filtops =
3865 { 1, NULL, filt_vfsdetach, filt_vfsvnode };
3866
3867 static void
3868 vfs_knllock(void *arg)
3869 {
3870 struct vnode *vp = arg;
3871
3872 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
3873 }
3874
3875 static void
3876 vfs_knlunlock(void *arg)
3877 {
3878 struct vnode *vp = arg;
3879
3880 VOP_UNLOCK(vp, 0, curthread);
3881 }
3882
3883 static int
3884 vfs_knllocked(void *arg)
3885 {
3886 struct vnode *vp = arg;
3887
3888 return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE);
3889 }
3890
3891 int
3892 vfs_kqfilter(struct vop_kqfilter_args *ap)
3893 {
3894 struct vnode *vp = ap->a_vp;
3895 struct knote *kn = ap->a_kn;
3896 struct knlist *knl;
3897
3898 switch (kn->kn_filter) {
3899 case EVFILT_READ:
3900 kn->kn_fop = &vfsread_filtops;
3901 break;
3902 case EVFILT_WRITE:
3903 kn->kn_fop = &vfswrite_filtops;
3904 break;
3905 case EVFILT_VNODE:
3906 kn->kn_fop = &vfsvnode_filtops;
3907 break;
3908 default:
3909 return (EINVAL);
3910 }
3911
3912 kn->kn_hook = (caddr_t)vp;
3913
3914 if (vp->v_pollinfo == NULL)
3915 v_addpollinfo(vp);
3916 if (vp->v_pollinfo == NULL)
3917 return (ENOMEM);
3918 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
3919 knlist_add(knl, kn, 0);
3920
3921 return (0);
3922 }
3923
3924 /*
3925 * Detach knote from vnode
3926 */
3927 static void
3928 filt_vfsdetach(struct knote *kn)
3929 {
3930 struct vnode *vp = (struct vnode *)kn->kn_hook;
3931
3932 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
3933 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
3934 }
3935
3936 /*ARGSUSED*/
3937 static int
3938 filt_vfsread(struct knote *kn, long hint)
3939 {
3940 struct vnode *vp = (struct vnode *)kn->kn_hook;
3941 struct vattr va;
3942
3943 /*
3944 * filesystem is gone, so set the EOF flag and schedule
3945 * the knote for deletion.
3946 */
3947 if (hint == NOTE_REVOKE) {
3948 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3949 return (1);
3950 }
3951
3952 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread))
3953 return (0);
3954
3955 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
3956 return (kn->kn_data != 0);
3957 }
3958
3959 /*ARGSUSED*/
3960 static int
3961 filt_vfswrite(struct knote *kn, long hint)
3962 {
3963 /*
3964 * filesystem is gone, so set the EOF flag and schedule
3965 * the knote for deletion.
3966 */
3967 if (hint == NOTE_REVOKE)
3968 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3969
3970 kn->kn_data = 0;
3971 return (1);
3972 }
3973
3974 static int
3975 filt_vfsvnode(struct knote *kn, long hint)
3976 {
3977 if (kn->kn_sfflags & hint)
3978 kn->kn_fflags |= hint;
3979 if (hint == NOTE_REVOKE) {
3980 kn->kn_flags |= EV_EOF;
3981 return (1);
3982 }
3983 return (kn->kn_fflags != 0);
3984 }
3985
3986 int
3987 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
3988 {
3989 int error;
3990
3991 if (dp->d_reclen > ap->a_uio->uio_resid)
3992 return (ENAMETOOLONG);
3993 error = uiomove(dp, dp->d_reclen, ap->a_uio);
3994 if (error) {
3995 if (ap->a_ncookies != NULL) {
3996 if (ap->a_cookies != NULL)
3997 free(ap->a_cookies, M_TEMP);
3998 ap->a_cookies = NULL;
3999 *ap->a_ncookies = 0;
4000 }
4001 return (error);
4002 }
4003 if (ap->a_ncookies == NULL)
4004 return (0);
4005
4006 KASSERT(ap->a_cookies,
4007 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
4008
4009 *ap->a_cookies = realloc(*ap->a_cookies,
4010 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
4011 (*ap->a_cookies)[*ap->a_ncookies] = off;
4012 return (0);
4013 }
4014
4015 /*
4016 * Mark for update the access time of the file if the filesystem
4017 * supports VA_MARK_ATIME. This functionality is used by execve
4018 * and mmap, so we want to avoid the synchronous I/O implied by
4019 * directly setting va_atime for the sake of efficiency.
4020 */
4021 void
4022 vfs_mark_atime(struct vnode *vp, struct thread *td)
4023 {
4024 struct vattr atimeattr;
4025
4026 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
4027 VATTR_NULL(&atimeattr);
4028 atimeattr.va_vaflags |= VA_MARK_ATIME;
4029 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td);
4030 }
4031 }
Cache object: 7d867306952e055c5bb7f05e5e09dcae
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