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: releng/6.3/sys/kern/vfs_subr.c 173886 2007-11-24 19:45:58Z cvs2svn $");
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/kdb.h>
59 #include <sys/kernel.h>
60 #include <sys/kthread.h>
61 #include <sys/mac.h>
62 #include <sys/malloc.h>
63 #include <sys/mount.h>
64 #include <sys/namei.h>
65 #include <sys/reboot.h>
66 #include <sys/sleepqueue.h>
67 #include <sys/stat.h>
68 #include <sys/sysctl.h>
69 #include <sys/syslog.h>
70 #include <sys/vmmeter.h>
71 #include <sys/vnode.h>
72
73 #include <machine/stdarg.h>
74
75 #include <vm/vm.h>
76 #include <vm/vm_object.h>
77 #include <vm/vm_extern.h>
78 #include <vm/pmap.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_kern.h>
82 #include <vm/uma.h>
83
84 #ifdef DDB
85 #include <ddb/ddb.h>
86 #endif
87
88 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
89
90 static void delmntque(struct vnode *vp);
91 static void insmntque(struct vnode *vp, struct mount *mp);
92 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
93 int slpflag, int slptimeo);
94 static void syncer_shutdown(void *arg, int howto);
95 static int vtryrecycle(struct vnode *vp);
96 static void vbusy(struct vnode *vp);
97 static void vinactive(struct vnode *, struct thread *);
98 static void v_incr_usecount(struct vnode *);
99 static void v_decr_usecount(struct vnode *);
100 static void v_decr_useonly(struct vnode *);
101 static void v_upgrade_usecount(struct vnode *);
102 static void vfree(struct vnode *);
103 static void vnlru_free(int);
104 static void vdestroy(struct vnode *);
105 static void vgonel(struct vnode *);
106 static void vfs_knllock(void *arg);
107 static void vfs_knlunlock(void *arg);
108 static int vfs_knllocked(void *arg);
109
110
111 /*
112 * Enable Giant pushdown based on whether or not the vm is mpsafe in this
113 * build. Without mpsafevm the buffer cache can not run Giant free.
114 */
115 #if defined(__alpha__) || defined(__amd64__) || defined(__i386__) || \
116 defined(__sparc64__)
117 int mpsafe_vfs = 1;
118 #else
119 int mpsafe_vfs;
120 #endif
121 TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs);
122 SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0,
123 "MPSAFE VFS");
124
125 /*
126 * Number of vnodes in existence. Increased whenever getnewvnode()
127 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed
128 * vnode.
129 */
130 static unsigned long numvnodes;
131
132 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
133
134 /*
135 * Conversion tables for conversion from vnode types to inode formats
136 * and back.
137 */
138 enum vtype iftovt_tab[16] = {
139 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
140 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
141 };
142 int vttoif_tab[10] = {
143 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
144 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
145 };
146
147 /*
148 * List of vnodes that are ready for recycling.
149 */
150 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
151
152 /*
153 * Free vnode target. Free vnodes may simply be files which have been stat'd
154 * but not read. This is somewhat common, and a small cache of such files
155 * should be kept to avoid recreation costs.
156 */
157 static u_long wantfreevnodes;
158 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
159 /* Number of vnodes in the free list. */
160 static u_long freevnodes;
161 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
162
163 /*
164 * Various variables used for debugging the new implementation of
165 * reassignbuf().
166 * XXX these are probably of (very) limited utility now.
167 */
168 static int reassignbufcalls;
169 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
170
171 /*
172 * Cache for the mount type id assigned to NFS. This is used for
173 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
174 */
175 int nfs_mount_type = -1;
176
177 /* To keep more than one thread at a time from running vfs_getnewfsid */
178 static struct mtx mntid_mtx;
179
180 /*
181 * Lock for any access to the following:
182 * vnode_free_list
183 * numvnodes
184 * freevnodes
185 */
186 static struct mtx vnode_free_list_mtx;
187
188 /* Publicly exported FS */
189 struct nfs_public nfs_pub;
190
191 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
192 static uma_zone_t vnode_zone;
193 static uma_zone_t vnodepoll_zone;
194
195 /* Set to 1 to print out reclaim of active vnodes */
196 int prtactive;
197
198 /*
199 * The workitem queue.
200 *
201 * It is useful to delay writes of file data and filesystem metadata
202 * for tens of seconds so that quickly created and deleted files need
203 * not waste disk bandwidth being created and removed. To realize this,
204 * we append vnodes to a "workitem" queue. When running with a soft
205 * updates implementation, most pending metadata dependencies should
206 * not wait for more than a few seconds. Thus, mounted on block devices
207 * are delayed only about a half the time that file data is delayed.
208 * Similarly, directory updates are more critical, so are only delayed
209 * about a third the time that file data is delayed. Thus, there are
210 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
211 * one each second (driven off the filesystem syncer process). The
212 * syncer_delayno variable indicates the next queue that is to be processed.
213 * Items that need to be processed soon are placed in this queue:
214 *
215 * syncer_workitem_pending[syncer_delayno]
216 *
217 * A delay of fifteen seconds is done by placing the request fifteen
218 * entries later in the queue:
219 *
220 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
221 *
222 */
223 static int syncer_delayno;
224 static long syncer_mask;
225 LIST_HEAD(synclist, bufobj);
226 static struct synclist *syncer_workitem_pending;
227 /*
228 * The sync_mtx protects:
229 * bo->bo_synclist
230 * sync_vnode_count
231 * syncer_delayno
232 * syncer_state
233 * syncer_workitem_pending
234 * syncer_worklist_len
235 * rushjob
236 */
237 static struct mtx sync_mtx;
238
239 #define SYNCER_MAXDELAY 32
240 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
241 static int syncdelay = 30; /* max time to delay syncing data */
242 static int filedelay = 30; /* time to delay syncing files */
243 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, "");
244 static int dirdelay = 29; /* time to delay syncing directories */
245 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, "");
246 static int metadelay = 28; /* time to delay syncing metadata */
247 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, "");
248 static int rushjob; /* number of slots to run ASAP */
249 static int stat_rush_requests; /* number of times I/O speeded up */
250 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
251
252 /*
253 * When shutting down the syncer, run it at four times normal speed.
254 */
255 #define SYNCER_SHUTDOWN_SPEEDUP 4
256 static int sync_vnode_count;
257 static int syncer_worklist_len;
258 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
259 syncer_state;
260
261 /*
262 * Number of vnodes we want to exist at any one time. This is mostly used
263 * to size hash tables in vnode-related code. It is normally not used in
264 * getnewvnode(), as wantfreevnodes is normally nonzero.)
265 *
266 * XXX desiredvnodes is historical cruft and should not exist.
267 */
268 int desiredvnodes;
269 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
270 &desiredvnodes, 0, "Maximum number of vnodes");
271 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
272 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
273 static int vnlru_nowhere;
274 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
275 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
276
277 /*
278 * Macros to control when a vnode is freed and recycled. All require
279 * the vnode interlock.
280 */
281 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
282 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
283 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
284
285
286 /*
287 * Initialize the vnode management data structures.
288 */
289 #ifndef MAXVNODES_MAX
290 #define MAXVNODES_MAX 100000
291 #endif
292 static void
293 vntblinit(void *dummy __unused)
294 {
295
296 /*
297 * Desiredvnodes is a function of the physical memory size and
298 * the kernel's heap size. Specifically, desiredvnodes scales
299 * in proportion to the physical memory size until two fifths
300 * of the kernel's heap size is consumed by vnodes and vm
301 * objects.
302 */
303 desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size /
304 (5 * (sizeof(struct vm_object) + sizeof(struct vnode))));
305 if (desiredvnodes > MAXVNODES_MAX) {
306 if (bootverbose)
307 printf("Reducing kern.maxvnodes %d -> %d\n",
308 desiredvnodes, MAXVNODES_MAX);
309 desiredvnodes = MAXVNODES_MAX;
310 }
311 wantfreevnodes = desiredvnodes / 4;
312 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
313 TAILQ_INIT(&vnode_free_list);
314 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
315 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
316 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
317 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
318 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
319 /*
320 * Initialize the filesystem syncer.
321 */
322 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
323 &syncer_mask);
324 syncer_maxdelay = syncer_mask + 1;
325 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
326 }
327 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL)
328
329
330 /*
331 * Mark a mount point as busy. Used to synchronize access and to delay
332 * unmounting. Interlock is not released on failure.
333 */
334 int
335 vfs_busy(mp, flags, interlkp, td)
336 struct mount *mp;
337 int flags;
338 struct mtx *interlkp;
339 struct thread *td;
340 {
341 int lkflags;
342
343 MNT_ILOCK(mp);
344 MNT_REF(mp);
345 if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
346 if (flags & LK_NOWAIT) {
347 MNT_REL(mp);
348 MNT_IUNLOCK(mp);
349 return (ENOENT);
350 }
351 if (interlkp)
352 mtx_unlock(interlkp);
353 mp->mnt_kern_flag |= MNTK_MWAIT;
354 /*
355 * Since all busy locks are shared except the exclusive
356 * lock granted when unmounting, the only place that a
357 * wakeup needs to be done is at the release of the
358 * exclusive lock at the end of dounmount.
359 */
360 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0);
361 MNT_REL(mp);
362 MNT_IUNLOCK(mp);
363 if (interlkp)
364 mtx_lock(interlkp);
365 return (ENOENT);
366 }
367 if (interlkp)
368 mtx_unlock(interlkp);
369 lkflags = LK_SHARED | LK_INTERLOCK;
370 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td))
371 panic("vfs_busy: unexpected lock failure");
372 return (0);
373 }
374
375 /*
376 * Free a busy filesystem.
377 */
378 void
379 vfs_unbusy(mp, td)
380 struct mount *mp;
381 struct thread *td;
382 {
383
384 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
385 vfs_rel(mp);
386 }
387
388 /*
389 * Lookup a mount point by filesystem identifier.
390 */
391 struct mount *
392 vfs_getvfs(fsid)
393 fsid_t *fsid;
394 {
395 struct mount *mp;
396
397 mtx_lock(&mountlist_mtx);
398 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
399 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
400 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
401 vfs_ref(mp);
402 mtx_unlock(&mountlist_mtx);
403 return (mp);
404 }
405 }
406 mtx_unlock(&mountlist_mtx);
407 return ((struct mount *) 0);
408 }
409
410 /*
411 * Check if a user can access priveledged mount options.
412 */
413 int
414 vfs_suser(struct mount *mp, struct thread *td)
415 {
416 int error;
417
418 if ((mp->mnt_flag & MNT_USER) == 0 ||
419 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
420 if ((error = suser(td)) != 0)
421 return (error);
422 }
423 return (0);
424 }
425
426 /*
427 * Get a new unique fsid. Try to make its val[0] unique, since this value
428 * will be used to create fake device numbers for stat(). Also try (but
429 * not so hard) make its val[0] unique mod 2^16, since some emulators only
430 * support 16-bit device numbers. We end up with unique val[0]'s for the
431 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
432 *
433 * Keep in mind that several mounts may be running in parallel. Starting
434 * the search one past where the previous search terminated is both a
435 * micro-optimization and a defense against returning the same fsid to
436 * different mounts.
437 */
438 void
439 vfs_getnewfsid(mp)
440 struct mount *mp;
441 {
442 static u_int16_t mntid_base;
443 struct mount *nmp;
444 fsid_t tfsid;
445 int mtype;
446
447 mtx_lock(&mntid_mtx);
448 mtype = mp->mnt_vfc->vfc_typenum;
449 tfsid.val[1] = mtype;
450 mtype = (mtype & 0xFF) << 24;
451 for (;;) {
452 tfsid.val[0] = makedev(255,
453 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
454 mntid_base++;
455 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
456 break;
457 vfs_rel(nmp);
458 }
459 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
460 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
461 mtx_unlock(&mntid_mtx);
462 }
463
464 /*
465 * Knob to control the precision of file timestamps:
466 *
467 * 0 = seconds only; nanoseconds zeroed.
468 * 1 = seconds and nanoseconds, accurate within 1/HZ.
469 * 2 = seconds and nanoseconds, truncated to microseconds.
470 * >=3 = seconds and nanoseconds, maximum precision.
471 */
472 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
473
474 static int timestamp_precision = TSP_SEC;
475 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
476 ×tamp_precision, 0, "");
477
478 /*
479 * Get a current timestamp.
480 */
481 void
482 vfs_timestamp(tsp)
483 struct timespec *tsp;
484 {
485 struct timeval tv;
486
487 switch (timestamp_precision) {
488 case TSP_SEC:
489 tsp->tv_sec = time_second;
490 tsp->tv_nsec = 0;
491 break;
492 case TSP_HZ:
493 getnanotime(tsp);
494 break;
495 case TSP_USEC:
496 microtime(&tv);
497 TIMEVAL_TO_TIMESPEC(&tv, tsp);
498 break;
499 case TSP_NSEC:
500 default:
501 nanotime(tsp);
502 break;
503 }
504 }
505
506 /*
507 * Set vnode attributes to VNOVAL
508 */
509 void
510 vattr_null(vap)
511 struct vattr *vap;
512 {
513
514 vap->va_type = VNON;
515 vap->va_size = VNOVAL;
516 vap->va_bytes = VNOVAL;
517 vap->va_mode = VNOVAL;
518 vap->va_nlink = VNOVAL;
519 vap->va_uid = VNOVAL;
520 vap->va_gid = VNOVAL;
521 vap->va_fsid = VNOVAL;
522 vap->va_fileid = VNOVAL;
523 vap->va_blocksize = VNOVAL;
524 vap->va_rdev = VNOVAL;
525 vap->va_atime.tv_sec = VNOVAL;
526 vap->va_atime.tv_nsec = VNOVAL;
527 vap->va_mtime.tv_sec = VNOVAL;
528 vap->va_mtime.tv_nsec = VNOVAL;
529 vap->va_ctime.tv_sec = VNOVAL;
530 vap->va_ctime.tv_nsec = VNOVAL;
531 vap->va_birthtime.tv_sec = VNOVAL;
532 vap->va_birthtime.tv_nsec = VNOVAL;
533 vap->va_flags = VNOVAL;
534 vap->va_gen = VNOVAL;
535 vap->va_vaflags = 0;
536 }
537
538 /*
539 * This routine is called when we have too many vnodes. It attempts
540 * to free <count> vnodes and will potentially free vnodes that still
541 * have VM backing store (VM backing store is typically the cause
542 * of a vnode blowout so we want to do this). Therefore, this operation
543 * is not considered cheap.
544 *
545 * A number of conditions may prevent a vnode from being reclaimed.
546 * the buffer cache may have references on the vnode, a directory
547 * vnode may still have references due to the namei cache representing
548 * underlying files, or the vnode may be in active use. It is not
549 * desireable to reuse such vnodes. These conditions may cause the
550 * number of vnodes to reach some minimum value regardless of what
551 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
552 */
553 static int
554 vlrureclaim(struct mount *mp)
555 {
556 struct thread *td;
557 struct vnode *vp;
558 int done;
559 int trigger;
560 int usevnodes;
561 int count;
562
563 /*
564 * Calculate the trigger point, don't allow user
565 * screwups to blow us up. This prevents us from
566 * recycling vnodes with lots of resident pages. We
567 * aren't trying to free memory, we are trying to
568 * free vnodes.
569 */
570 usevnodes = desiredvnodes;
571 if (usevnodes <= 0)
572 usevnodes = 1;
573 trigger = cnt.v_page_count * 2 / usevnodes;
574 done = 0;
575 td = curthread;
576 vn_start_write(NULL, &mp, V_WAIT);
577 MNT_ILOCK(mp);
578 count = mp->mnt_nvnodelistsize / 10 + 1;
579 while (count != 0) {
580 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
581 while (vp != NULL && vp->v_type == VMARKER)
582 vp = TAILQ_NEXT(vp, v_nmntvnodes);
583 if (vp == NULL)
584 break;
585 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
586 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
587 --count;
588 if (!VI_TRYLOCK(vp))
589 goto next_iter;
590 /*
591 * If it's been deconstructed already, it's still
592 * referenced, or it exceeds the trigger, skip it.
593 */
594 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
595 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
596 vp->v_object->resident_page_count > trigger)) {
597 VI_UNLOCK(vp);
598 goto next_iter;
599 }
600 MNT_IUNLOCK(mp);
601 vholdl(vp);
602 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) {
603 vdrop(vp);
604 goto next_iter_mntunlocked;
605 }
606 VI_LOCK(vp);
607 /*
608 * v_usecount may have been bumped after VOP_LOCK() dropped
609 * the vnode interlock and before it was locked again.
610 *
611 * It is not necessary to recheck VI_DOOMED because it can
612 * only be set by another thread that holds both the vnode
613 * lock and vnode interlock. If another thread has the
614 * vnode lock before we get to VOP_LOCK() and obtains the
615 * vnode interlock after VOP_LOCK() drops the vnode
616 * interlock, the other thread will be unable to drop the
617 * vnode lock before our VOP_LOCK() call fails.
618 */
619 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
620 (vp->v_object != NULL &&
621 vp->v_object->resident_page_count > trigger)) {
622 VOP_UNLOCK(vp, LK_INTERLOCK, td);
623 goto next_iter_mntunlocked;
624 }
625 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
626 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
627 vgonel(vp);
628 VOP_UNLOCK(vp, 0, td);
629 vdropl(vp);
630 done++;
631 next_iter_mntunlocked:
632 if ((count % 256) != 0)
633 goto relock_mnt;
634 goto yield;
635 next_iter:
636 if ((count % 256) != 0)
637 continue;
638 MNT_IUNLOCK(mp);
639 yield:
640 uio_yield();
641 relock_mnt:
642 MNT_ILOCK(mp);
643 }
644 MNT_IUNLOCK(mp);
645 vn_finished_write(mp);
646 return done;
647 }
648
649 /*
650 * Attempt to keep the free list at wantfreevnodes length.
651 */
652 static void
653 vnlru_free(int count)
654 {
655 struct vnode *vp;
656 int vfslocked;
657
658 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
659 for (; count > 0; count--) {
660 vp = TAILQ_FIRST(&vnode_free_list);
661 /*
662 * The list can be modified while the free_list_mtx
663 * has been dropped and vp could be NULL here.
664 */
665 if (!vp)
666 break;
667 VNASSERT(vp->v_op != NULL, vp,
668 ("vnlru_free: vnode already reclaimed."));
669 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
670 /*
671 * Don't recycle if we can't get the interlock.
672 */
673 if (!VI_TRYLOCK(vp)) {
674 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
675 continue;
676 }
677 VNASSERT(VCANRECYCLE(vp), vp,
678 ("vp inconsistent on freelist"));
679 freevnodes--;
680 vp->v_iflag &= ~VI_FREE;
681 vholdl(vp);
682 mtx_unlock(&vnode_free_list_mtx);
683 VI_UNLOCK(vp);
684 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
685 vtryrecycle(vp);
686 VFS_UNLOCK_GIANT(vfslocked);
687 /*
688 * If the recycled succeeded this vdrop will actually free
689 * the vnode. If not it will simply place it back on
690 * the free list.
691 */
692 vdrop(vp);
693 mtx_lock(&vnode_free_list_mtx);
694 }
695 }
696 /*
697 * Attempt to recycle vnodes in a context that is always safe to block.
698 * Calling vlrurecycle() from the bowels of filesystem code has some
699 * interesting deadlock problems.
700 */
701 static struct proc *vnlruproc;
702 static int vnlruproc_sig;
703
704 static void
705 vnlru_proc(void)
706 {
707 struct mount *mp, *nmp;
708 int done;
709 struct proc *p = vnlruproc;
710 struct thread *td = FIRST_THREAD_IN_PROC(p);
711
712 mtx_lock(&Giant);
713
714 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
715 SHUTDOWN_PRI_FIRST);
716
717 for (;;) {
718 kthread_suspend_check(p);
719 mtx_lock(&vnode_free_list_mtx);
720 if (freevnodes > wantfreevnodes)
721 vnlru_free(freevnodes - wantfreevnodes);
722 if (numvnodes <= desiredvnodes * 9 / 10) {
723 vnlruproc_sig = 0;
724 wakeup(&vnlruproc_sig);
725 msleep(vnlruproc, &vnode_free_list_mtx,
726 PVFS|PDROP, "vlruwt", hz);
727 continue;
728 }
729 mtx_unlock(&vnode_free_list_mtx);
730 done = 0;
731 mtx_lock(&mountlist_mtx);
732 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
733 int vfsunlocked;
734 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
735 nmp = TAILQ_NEXT(mp, mnt_list);
736 continue;
737 }
738 if (!VFS_NEEDSGIANT(mp)) {
739 mtx_unlock(&Giant);
740 vfsunlocked = 1;
741 } else
742 vfsunlocked = 0;
743 done += vlrureclaim(mp);
744 if (vfsunlocked)
745 mtx_lock(&Giant);
746 mtx_lock(&mountlist_mtx);
747 nmp = TAILQ_NEXT(mp, mnt_list);
748 vfs_unbusy(mp, td);
749 }
750 mtx_unlock(&mountlist_mtx);
751 if (done == 0) {
752 #if 0
753 /* These messages are temporary debugging aids */
754 if (vnlru_nowhere < 5)
755 printf("vnlru process getting nowhere..\n");
756 else if (vnlru_nowhere == 5)
757 printf("vnlru process messages stopped.\n");
758 #endif
759 vnlru_nowhere++;
760 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
761 } else
762 uio_yield();
763 }
764 }
765
766 static struct kproc_desc vnlru_kp = {
767 "vnlru",
768 vnlru_proc,
769 &vnlruproc
770 };
771 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp)
772
773 /*
774 * Routines having to do with the management of the vnode table.
775 */
776
777 static void
778 vdestroy(struct vnode *vp)
779 {
780 struct bufobj *bo;
781
782 CTR1(KTR_VFS, "vdestroy vp %p", vp);
783 mtx_lock(&vnode_free_list_mtx);
784 numvnodes--;
785 mtx_unlock(&vnode_free_list_mtx);
786 bo = &vp->v_bufobj;
787 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
788 ("cleaned vnode still on the free list."));
789 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
790 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
791 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
792 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
793 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
794 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
795 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
796 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
797 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
798 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
799 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
800 VI_UNLOCK(vp);
801 #ifdef MAC
802 mac_destroy_vnode(vp);
803 #endif
804 if (vp->v_pollinfo != NULL) {
805 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note);
806 mtx_destroy(&vp->v_pollinfo->vpi_lock);
807 uma_zfree(vnodepoll_zone, vp->v_pollinfo);
808 }
809 #ifdef INVARIANTS
810 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */
811 vp->v_op = NULL;
812 #endif
813 lockdestroy(vp->v_vnlock);
814 mtx_destroy(&vp->v_interlock);
815 uma_zfree(vnode_zone, vp);
816 }
817
818 /*
819 * Try to recycle a freed vnode. We abort if anyone picks up a reference
820 * before we actually vgone(). This function must be called with the vnode
821 * held to prevent the vnode from being returned to the free list midway
822 * through vgone().
823 */
824 static int
825 vtryrecycle(struct vnode *vp)
826 {
827 struct thread *td = curthread;
828 struct mount *vnmp;
829
830 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp);
831 VNASSERT(vp->v_holdcnt, vp,
832 ("vtryrecycle: Recycling vp %p without a reference.", vp));
833 /*
834 * This vnode may found and locked via some other list, if so we
835 * can't recycle it yet.
836 */
837 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0)
838 return (EWOULDBLOCK);
839 /*
840 * Don't recycle if its filesystem is being suspended.
841 */
842 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
843 VOP_UNLOCK(vp, 0, td);
844 return (EBUSY);
845 }
846 /*
847 * If we got this far, we need to acquire the interlock and see if
848 * anyone picked up this vnode from another list. If not, we will
849 * mark it with DOOMED via vgonel() so that anyone who does find it
850 * will skip over it.
851 */
852 VI_LOCK(vp);
853 if (vp->v_usecount) {
854 VOP_UNLOCK(vp, LK_INTERLOCK, td);
855 vn_finished_write(vnmp);
856 return (EBUSY);
857 }
858 if ((vp->v_iflag & VI_DOOMED) == 0)
859 vgonel(vp);
860 VOP_UNLOCK(vp, LK_INTERLOCK, td);
861 vn_finished_write(vnmp);
862 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp);
863 return (0);
864 }
865
866 /*
867 * Return the next vnode from the free list.
868 */
869 int
870 getnewvnode(tag, mp, vops, vpp)
871 const char *tag;
872 struct mount *mp;
873 struct vop_vector *vops;
874 struct vnode **vpp;
875 {
876 struct vnode *vp = NULL;
877 struct bufobj *bo;
878
879 mtx_lock(&vnode_free_list_mtx);
880 /*
881 * Lend our context to reclaim vnodes if they've exceeded the max.
882 */
883 if (freevnodes > wantfreevnodes)
884 vnlru_free(1);
885 /*
886 * Wait for available vnodes.
887 */
888 if (numvnodes > desiredvnodes) {
889 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
890 /*
891 * File system is beeing suspended, we cannot risk a
892 * deadlock here, so allocate new vnode anyway.
893 */
894 if (freevnodes > wantfreevnodes)
895 vnlru_free(freevnodes - wantfreevnodes);
896 goto alloc;
897 }
898 if (vnlruproc_sig == 0) {
899 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
900 wakeup(vnlruproc);
901 }
902 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
903 "vlruwk", hz);
904 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
905 if (numvnodes > desiredvnodes) {
906 mtx_unlock(&vnode_free_list_mtx);
907 return (ENFILE);
908 }
909 #endif
910 }
911 alloc:
912 numvnodes++;
913 mtx_unlock(&vnode_free_list_mtx);
914 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
915 /*
916 * Setup locks.
917 */
918 vp->v_vnlock = &vp->v_lock;
919 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
920 /*
921 * By default, don't allow shared locks unless filesystems
922 * opt-in.
923 */
924 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
925 /*
926 * Initialize bufobj.
927 */
928 bo = &vp->v_bufobj;
929 bo->__bo_vnode = vp;
930 bo->bo_mtx = &vp->v_interlock;
931 bo->bo_ops = &buf_ops_bio;
932 bo->bo_private = vp;
933 TAILQ_INIT(&bo->bo_clean.bv_hd);
934 TAILQ_INIT(&bo->bo_dirty.bv_hd);
935 /*
936 * Initialize namecache.
937 */
938 LIST_INIT(&vp->v_cache_src);
939 TAILQ_INIT(&vp->v_cache_dst);
940 /*
941 * Finalize various vnode identity bits.
942 */
943 vp->v_type = VNON;
944 vp->v_tag = tag;
945 vp->v_op = vops;
946 v_incr_usecount(vp);
947 vp->v_data = 0;
948 #ifdef MAC
949 mac_init_vnode(vp);
950 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
951 mac_associate_vnode_singlelabel(mp, vp);
952 else if (mp == NULL)
953 printf("NULL mp in getnewvnode()\n");
954 #endif
955 if (mp != NULL) {
956 insmntque(vp, mp);
957 bo->bo_bsize = mp->mnt_stat.f_iosize;
958 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
959 vp->v_vflag |= VV_NOKNOTE;
960 }
961
962 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp);
963 *vpp = vp;
964 return (0);
965 }
966
967 /*
968 * Delete from old mount point vnode list, if on one.
969 */
970 static void
971 delmntque(struct vnode *vp)
972 {
973 struct mount *mp;
974
975 mp = vp->v_mount;
976 if (mp == NULL)
977 return;
978 MNT_ILOCK(mp);
979 vp->v_mount = NULL;
980 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
981 ("bad mount point vnode list size"));
982 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
983 mp->mnt_nvnodelistsize--;
984 MNT_REL(mp);
985 MNT_IUNLOCK(mp);
986 }
987
988 /*
989 * Insert into list of vnodes for the new mount point, if available.
990 */
991 static void
992 insmntque(struct vnode *vp, struct mount *mp)
993 {
994
995 vp->v_mount = mp;
996 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
997 MNT_ILOCK(mp);
998 MNT_REF(mp);
999 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1000 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1001 ("neg mount point vnode list size"));
1002 mp->mnt_nvnodelistsize++;
1003 MNT_IUNLOCK(mp);
1004 }
1005
1006 /*
1007 * Flush out and invalidate all buffers associated with a bufobj
1008 * Called with the underlying object locked.
1009 */
1010 int
1011 bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, int slptimeo)
1012 {
1013 int error;
1014
1015 BO_LOCK(bo);
1016 if (flags & V_SAVE) {
1017 error = bufobj_wwait(bo, slpflag, slptimeo);
1018 if (error) {
1019 BO_UNLOCK(bo);
1020 return (error);
1021 }
1022 if (bo->bo_dirty.bv_cnt > 0) {
1023 BO_UNLOCK(bo);
1024 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0)
1025 return (error);
1026 /*
1027 * XXX We could save a lock/unlock if this was only
1028 * enabled under INVARIANTS
1029 */
1030 BO_LOCK(bo);
1031 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1032 panic("vinvalbuf: dirty bufs");
1033 }
1034 }
1035 /*
1036 * If you alter this loop please notice that interlock is dropped and
1037 * reacquired in flushbuflist. Special care is needed to ensure that
1038 * no race conditions occur from this.
1039 */
1040 do {
1041 error = flushbuflist(&bo->bo_clean,
1042 flags, bo, slpflag, slptimeo);
1043 if (error == 0)
1044 error = flushbuflist(&bo->bo_dirty,
1045 flags, bo, slpflag, slptimeo);
1046 if (error != 0 && error != EAGAIN) {
1047 BO_UNLOCK(bo);
1048 return (error);
1049 }
1050 } while (error != 0);
1051
1052 /*
1053 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1054 * have write I/O in-progress but if there is a VM object then the
1055 * VM object can also have read-I/O in-progress.
1056 */
1057 do {
1058 bufobj_wwait(bo, 0, 0);
1059 BO_UNLOCK(bo);
1060 if (bo->bo_object != NULL) {
1061 VM_OBJECT_LOCK(bo->bo_object);
1062 vm_object_pip_wait(bo->bo_object, "bovlbx");
1063 VM_OBJECT_UNLOCK(bo->bo_object);
1064 }
1065 BO_LOCK(bo);
1066 } while (bo->bo_numoutput > 0);
1067 BO_UNLOCK(bo);
1068
1069 /*
1070 * Destroy the copy in the VM cache, too.
1071 */
1072 if (bo->bo_object != NULL) {
1073 VM_OBJECT_LOCK(bo->bo_object);
1074 vm_object_page_remove(bo->bo_object, 0, 0,
1075 (flags & V_SAVE) ? TRUE : FALSE);
1076 VM_OBJECT_UNLOCK(bo->bo_object);
1077 }
1078
1079 #ifdef INVARIANTS
1080 BO_LOCK(bo);
1081 if ((flags & (V_ALT | V_NORMAL)) == 0 &&
1082 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1083 panic("vinvalbuf: flush failed");
1084 BO_UNLOCK(bo);
1085 #endif
1086 return (0);
1087 }
1088
1089 /*
1090 * Flush out and invalidate all buffers associated with a vnode.
1091 * Called with the underlying object locked.
1092 */
1093 int
1094 vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, int slptimeo)
1095 {
1096
1097 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags);
1098 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1099 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo));
1100 }
1101
1102 /*
1103 * Flush out buffers on the specified list.
1104 *
1105 */
1106 static int
1107 flushbuflist(bufv, flags, bo, slpflag, slptimeo)
1108 struct bufv *bufv;
1109 int flags;
1110 struct bufobj *bo;
1111 int slpflag, slptimeo;
1112 {
1113 struct buf *bp, *nbp;
1114 int retval, error;
1115 daddr_t lblkno;
1116 b_xflags_t xflags;
1117
1118 ASSERT_BO_LOCKED(bo);
1119
1120 retval = 0;
1121 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1122 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1123 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1124 continue;
1125 }
1126 lblkno = 0;
1127 xflags = 0;
1128 if (nbp != NULL) {
1129 lblkno = nbp->b_lblkno;
1130 xflags = nbp->b_xflags &
1131 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1132 }
1133 retval = EAGAIN;
1134 error = BUF_TIMELOCK(bp,
1135 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1136 "flushbuf", slpflag, slptimeo);
1137 if (error) {
1138 BO_LOCK(bo);
1139 return (error != ENOLCK ? error : EAGAIN);
1140 }
1141 KASSERT(bp->b_bufobj == bo,
1142 ("bp %p wrong b_bufobj %p should be %p",
1143 bp, bp->b_bufobj, bo));
1144 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1145 BUF_UNLOCK(bp);
1146 BO_LOCK(bo);
1147 return (EAGAIN);
1148 }
1149 /*
1150 * XXX Since there are no node locks for NFS, I
1151 * believe there is a slight chance that a delayed
1152 * write will occur while sleeping just above, so
1153 * check for it.
1154 */
1155 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1156 (flags & V_SAVE)) {
1157 bremfree(bp);
1158 bp->b_flags |= B_ASYNC;
1159 bwrite(bp);
1160 BO_LOCK(bo);
1161 return (EAGAIN); /* XXX: why not loop ? */
1162 }
1163 bremfree(bp);
1164 bp->b_flags |= (B_INVAL | B_RELBUF);
1165 bp->b_flags &= ~B_ASYNC;
1166 brelse(bp);
1167 BO_LOCK(bo);
1168 if (nbp != NULL &&
1169 (nbp->b_bufobj != bo ||
1170 nbp->b_lblkno != lblkno ||
1171 (nbp->b_xflags &
1172 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1173 break; /* nbp invalid */
1174 }
1175 return (retval);
1176 }
1177
1178 /*
1179 * Truncate a file's buffer and pages to a specified length. This
1180 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1181 * sync activity.
1182 */
1183 int
1184 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td, off_t length, int blksize)
1185 {
1186 struct buf *bp, *nbp;
1187 int anyfreed;
1188 int trunclbn;
1189 struct bufobj *bo;
1190
1191 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length);
1192 /*
1193 * Round up to the *next* lbn.
1194 */
1195 trunclbn = (length + blksize - 1) / blksize;
1196
1197 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1198 restart:
1199 VI_LOCK(vp);
1200 bo = &vp->v_bufobj;
1201 anyfreed = 1;
1202 for (;anyfreed;) {
1203 anyfreed = 0;
1204 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1205 if (bp->b_lblkno < trunclbn)
1206 continue;
1207 if (BUF_LOCK(bp,
1208 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1209 VI_MTX(vp)) == ENOLCK)
1210 goto restart;
1211
1212 bremfree(bp);
1213 bp->b_flags |= (B_INVAL | B_RELBUF);
1214 bp->b_flags &= ~B_ASYNC;
1215 brelse(bp);
1216 anyfreed = 1;
1217
1218 if (nbp != NULL &&
1219 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1220 (nbp->b_vp != vp) ||
1221 (nbp->b_flags & B_DELWRI))) {
1222 goto restart;
1223 }
1224 VI_LOCK(vp);
1225 }
1226
1227 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1228 if (bp->b_lblkno < trunclbn)
1229 continue;
1230 if (BUF_LOCK(bp,
1231 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1232 VI_MTX(vp)) == ENOLCK)
1233 goto restart;
1234 bremfree(bp);
1235 bp->b_flags |= (B_INVAL | B_RELBUF);
1236 bp->b_flags &= ~B_ASYNC;
1237 brelse(bp);
1238 anyfreed = 1;
1239 if (nbp != NULL &&
1240 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1241 (nbp->b_vp != vp) ||
1242 (nbp->b_flags & B_DELWRI) == 0)) {
1243 goto restart;
1244 }
1245 VI_LOCK(vp);
1246 }
1247 }
1248
1249 if (length > 0) {
1250 restartsync:
1251 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1252 if (bp->b_lblkno > 0)
1253 continue;
1254 /*
1255 * Since we hold the vnode lock this should only
1256 * fail if we're racing with the buf daemon.
1257 */
1258 if (BUF_LOCK(bp,
1259 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1260 VI_MTX(vp)) == ENOLCK) {
1261 goto restart;
1262 }
1263 VNASSERT((bp->b_flags & B_DELWRI), vp,
1264 ("buf(%p) on dirty queue without DELWRI", bp));
1265
1266 bremfree(bp);
1267 bawrite(bp);
1268 VI_LOCK(vp);
1269 goto restartsync;
1270 }
1271 }
1272
1273 bufobj_wwait(bo, 0, 0);
1274 VI_UNLOCK(vp);
1275 vnode_pager_setsize(vp, length);
1276
1277 return (0);
1278 }
1279
1280 /*
1281 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1282 * a vnode.
1283 *
1284 * NOTE: We have to deal with the special case of a background bitmap
1285 * buffer, a situation where two buffers will have the same logical
1286 * block offset. We want (1) only the foreground buffer to be accessed
1287 * in a lookup and (2) must differentiate between the foreground and
1288 * background buffer in the splay tree algorithm because the splay
1289 * tree cannot normally handle multiple entities with the same 'index'.
1290 * We accomplish this by adding differentiating flags to the splay tree's
1291 * numerical domain.
1292 */
1293 static
1294 struct buf *
1295 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1296 {
1297 struct buf dummy;
1298 struct buf *lefttreemax, *righttreemin, *y;
1299
1300 if (root == NULL)
1301 return (NULL);
1302 lefttreemax = righttreemin = &dummy;
1303 for (;;) {
1304 if (lblkno < root->b_lblkno ||
1305 (lblkno == root->b_lblkno &&
1306 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1307 if ((y = root->b_left) == NULL)
1308 break;
1309 if (lblkno < y->b_lblkno) {
1310 /* Rotate right. */
1311 root->b_left = y->b_right;
1312 y->b_right = root;
1313 root = y;
1314 if ((y = root->b_left) == NULL)
1315 break;
1316 }
1317 /* Link into the new root's right tree. */
1318 righttreemin->b_left = root;
1319 righttreemin = root;
1320 } else if (lblkno > root->b_lblkno ||
1321 (lblkno == root->b_lblkno &&
1322 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1323 if ((y = root->b_right) == NULL)
1324 break;
1325 if (lblkno > y->b_lblkno) {
1326 /* Rotate left. */
1327 root->b_right = y->b_left;
1328 y->b_left = root;
1329 root = y;
1330 if ((y = root->b_right) == NULL)
1331 break;
1332 }
1333 /* Link into the new root's left tree. */
1334 lefttreemax->b_right = root;
1335 lefttreemax = root;
1336 } else {
1337 break;
1338 }
1339 root = y;
1340 }
1341 /* Assemble the new root. */
1342 lefttreemax->b_right = root->b_left;
1343 righttreemin->b_left = root->b_right;
1344 root->b_left = dummy.b_right;
1345 root->b_right = dummy.b_left;
1346 return (root);
1347 }
1348
1349 static void
1350 buf_vlist_remove(struct buf *bp)
1351 {
1352 struct buf *root;
1353 struct bufv *bv;
1354
1355 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1356 ASSERT_BO_LOCKED(bp->b_bufobj);
1357 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1358 (BX_VNDIRTY|BX_VNCLEAN),
1359 ("buf_vlist_remove: Buf %p is on two lists", bp));
1360 if (bp->b_xflags & BX_VNDIRTY)
1361 bv = &bp->b_bufobj->bo_dirty;
1362 else
1363 bv = &bp->b_bufobj->bo_clean;
1364 if (bp != bv->bv_root) {
1365 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1366 KASSERT(root == bp, ("splay lookup failed in remove"));
1367 }
1368 if (bp->b_left == NULL) {
1369 root = bp->b_right;
1370 } else {
1371 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1372 root->b_right = bp->b_right;
1373 }
1374 bv->bv_root = root;
1375 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1376 bv->bv_cnt--;
1377 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1378 }
1379
1380 /*
1381 * Add the buffer to the sorted clean or dirty block list using a
1382 * splay tree algorithm.
1383 *
1384 * NOTE: xflags is passed as a constant, optimizing this inline function!
1385 */
1386 static void
1387 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1388 {
1389 struct buf *root;
1390 struct bufv *bv;
1391
1392 ASSERT_BO_LOCKED(bo);
1393 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1394 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1395 bp->b_xflags |= xflags;
1396 if (xflags & BX_VNDIRTY)
1397 bv = &bo->bo_dirty;
1398 else
1399 bv = &bo->bo_clean;
1400
1401 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1402 if (root == NULL) {
1403 bp->b_left = NULL;
1404 bp->b_right = NULL;
1405 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1406 } else if (bp->b_lblkno < root->b_lblkno ||
1407 (bp->b_lblkno == root->b_lblkno &&
1408 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1409 bp->b_left = root->b_left;
1410 bp->b_right = root;
1411 root->b_left = NULL;
1412 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1413 } else {
1414 bp->b_right = root->b_right;
1415 bp->b_left = root;
1416 root->b_right = NULL;
1417 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1418 }
1419 bv->bv_cnt++;
1420 bv->bv_root = bp;
1421 }
1422
1423 /*
1424 * Lookup a buffer using the splay tree. Note that we specifically avoid
1425 * shadow buffers used in background bitmap writes.
1426 *
1427 * This code isn't quite efficient as it could be because we are maintaining
1428 * two sorted lists and do not know which list the block resides in.
1429 *
1430 * During a "make buildworld" the desired buffer is found at one of
1431 * the roots more than 60% of the time. Thus, checking both roots
1432 * before performing either splay eliminates unnecessary splays on the
1433 * first tree splayed.
1434 */
1435 struct buf *
1436 gbincore(struct bufobj *bo, daddr_t lblkno)
1437 {
1438 struct buf *bp;
1439
1440 ASSERT_BO_LOCKED(bo);
1441 if ((bp = bo->bo_clean.bv_root) != NULL &&
1442 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1443 return (bp);
1444 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1445 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1446 return (bp);
1447 if ((bp = bo->bo_clean.bv_root) != NULL) {
1448 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1449 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1450 return (bp);
1451 }
1452 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1453 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1454 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1455 return (bp);
1456 }
1457 return (NULL);
1458 }
1459
1460 /*
1461 * Associate a buffer with a vnode.
1462 */
1463 void
1464 bgetvp(struct vnode *vp, struct buf *bp)
1465 {
1466
1467 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1468
1469 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1470 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1471 ("bgetvp: bp already attached! %p", bp));
1472
1473 ASSERT_VI_LOCKED(vp, "bgetvp");
1474 vholdl(vp);
1475 bp->b_vp = vp;
1476 bp->b_bufobj = &vp->v_bufobj;
1477 /*
1478 * Insert onto list for new vnode.
1479 */
1480 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN);
1481 }
1482
1483 /*
1484 * Disassociate a buffer from a vnode.
1485 */
1486 void
1487 brelvp(struct buf *bp)
1488 {
1489 struct bufobj *bo;
1490 struct vnode *vp;
1491
1492 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1493 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1494
1495 /*
1496 * Delete from old vnode list, if on one.
1497 */
1498 vp = bp->b_vp; /* XXX */
1499 bo = bp->b_bufobj;
1500 BO_LOCK(bo);
1501 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1502 buf_vlist_remove(bp);
1503 else
1504 panic("brelvp: Buffer %p not on queue.", bp);
1505 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1506 bo->bo_flag &= ~BO_ONWORKLST;
1507 mtx_lock(&sync_mtx);
1508 LIST_REMOVE(bo, bo_synclist);
1509 syncer_worklist_len--;
1510 mtx_unlock(&sync_mtx);
1511 }
1512 bp->b_vp = NULL;
1513 bp->b_bufobj = NULL;
1514 vdropl(vp);
1515 }
1516
1517 /*
1518 * Add an item to the syncer work queue.
1519 */
1520 static void
1521 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1522 {
1523 int slot;
1524
1525 ASSERT_BO_LOCKED(bo);
1526
1527 mtx_lock(&sync_mtx);
1528 if (bo->bo_flag & BO_ONWORKLST)
1529 LIST_REMOVE(bo, bo_synclist);
1530 else {
1531 bo->bo_flag |= BO_ONWORKLST;
1532 syncer_worklist_len++;
1533 }
1534
1535 if (delay > syncer_maxdelay - 2)
1536 delay = syncer_maxdelay - 2;
1537 slot = (syncer_delayno + delay) & syncer_mask;
1538
1539 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
1540 mtx_unlock(&sync_mtx);
1541 }
1542
1543 static int
1544 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1545 {
1546 int error, len;
1547
1548 mtx_lock(&sync_mtx);
1549 len = syncer_worklist_len - sync_vnode_count;
1550 mtx_unlock(&sync_mtx);
1551 error = SYSCTL_OUT(req, &len, sizeof(len));
1552 return (error);
1553 }
1554
1555 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1556 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1557
1558 static struct proc *updateproc;
1559 static void sched_sync(void);
1560 static struct kproc_desc up_kp = {
1561 "syncer",
1562 sched_sync,
1563 &updateproc
1564 };
1565 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
1566
1567 static int
1568 sync_vnode(struct bufobj *bo, struct thread *td)
1569 {
1570 struct vnode *vp;
1571 struct mount *mp;
1572
1573 vp = bo->__bo_vnode; /* XXX */
1574 if (VOP_ISLOCKED(vp, NULL) != 0)
1575 return (1);
1576 if (VI_TRYLOCK(vp) == 0)
1577 return (1);
1578 /*
1579 * We use vhold in case the vnode does not
1580 * successfully sync. vhold prevents the vnode from
1581 * going away when we unlock the sync_mtx so that
1582 * we can acquire the vnode interlock.
1583 */
1584 vholdl(vp);
1585 mtx_unlock(&sync_mtx);
1586 VI_UNLOCK(vp);
1587 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1588 vdrop(vp);
1589 mtx_lock(&sync_mtx);
1590 return (1);
1591 }
1592 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1593 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1594 VOP_UNLOCK(vp, 0, td);
1595 vn_finished_write(mp);
1596 VI_LOCK(vp);
1597 if ((bo->bo_flag & BO_ONWORKLST) != 0) {
1598 /*
1599 * Put us back on the worklist. The worklist
1600 * routine will remove us from our current
1601 * position and then add us back in at a later
1602 * position.
1603 */
1604 vn_syncer_add_to_worklist(bo, syncdelay);
1605 }
1606 vdropl(vp);
1607 mtx_lock(&sync_mtx);
1608 return (0);
1609 }
1610
1611 /*
1612 * System filesystem synchronizer daemon.
1613 */
1614 static void
1615 sched_sync(void)
1616 {
1617 struct synclist *next;
1618 struct synclist *slp;
1619 struct bufobj *bo;
1620 long starttime;
1621 struct thread *td = FIRST_THREAD_IN_PROC(updateproc);
1622 static int dummychan;
1623 int last_work_seen;
1624 int net_worklist_len;
1625 int syncer_final_iter;
1626 int first_printf;
1627 int error;
1628
1629 mtx_lock(&Giant);
1630 last_work_seen = 0;
1631 syncer_final_iter = 0;
1632 first_printf = 1;
1633 syncer_state = SYNCER_RUNNING;
1634 starttime = time_second;
1635 td->td_pflags |= TDP_NORUNNINGBUF;
1636
1637 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1638 SHUTDOWN_PRI_LAST);
1639
1640 for (;;) {
1641 mtx_lock(&sync_mtx);
1642 if (syncer_state == SYNCER_FINAL_DELAY &&
1643 syncer_final_iter == 0) {
1644 mtx_unlock(&sync_mtx);
1645 kthread_suspend_check(td->td_proc);
1646 mtx_lock(&sync_mtx);
1647 }
1648 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1649 if (syncer_state != SYNCER_RUNNING &&
1650 starttime != time_second) {
1651 if (first_printf) {
1652 printf("\nSyncing disks, vnodes remaining...");
1653 first_printf = 0;
1654 }
1655 printf("%d ", net_worklist_len);
1656 }
1657 starttime = time_second;
1658
1659 /*
1660 * Push files whose dirty time has expired. Be careful
1661 * of interrupt race on slp queue.
1662 *
1663 * Skip over empty worklist slots when shutting down.
1664 */
1665 do {
1666 slp = &syncer_workitem_pending[syncer_delayno];
1667 syncer_delayno += 1;
1668 if (syncer_delayno == syncer_maxdelay)
1669 syncer_delayno = 0;
1670 next = &syncer_workitem_pending[syncer_delayno];
1671 /*
1672 * If the worklist has wrapped since the
1673 * it was emptied of all but syncer vnodes,
1674 * switch to the FINAL_DELAY state and run
1675 * for one more second.
1676 */
1677 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1678 net_worklist_len == 0 &&
1679 last_work_seen == syncer_delayno) {
1680 syncer_state = SYNCER_FINAL_DELAY;
1681 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1682 }
1683 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1684 syncer_worklist_len > 0);
1685
1686 /*
1687 * Keep track of the last time there was anything
1688 * on the worklist other than syncer vnodes.
1689 * Return to the SHUTTING_DOWN state if any
1690 * new work appears.
1691 */
1692 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1693 last_work_seen = syncer_delayno;
1694 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1695 syncer_state = SYNCER_SHUTTING_DOWN;
1696 while ((bo = LIST_FIRST(slp)) != NULL) {
1697 error = sync_vnode(bo, td);
1698 if (error == 1) {
1699 LIST_REMOVE(bo, bo_synclist);
1700 LIST_INSERT_HEAD(next, bo, bo_synclist);
1701 continue;
1702 }
1703 }
1704 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1705 syncer_final_iter--;
1706 mtx_unlock(&sync_mtx);
1707 /*
1708 * The variable rushjob allows the kernel to speed up the
1709 * processing of the filesystem syncer process. A rushjob
1710 * value of N tells the filesystem syncer to process the next
1711 * N seconds worth of work on its queue ASAP. Currently rushjob
1712 * is used by the soft update code to speed up the filesystem
1713 * syncer process when the incore state is getting so far
1714 * ahead of the disk that the kernel memory pool is being
1715 * threatened with exhaustion.
1716 */
1717 mtx_lock(&sync_mtx);
1718 if (rushjob > 0) {
1719 rushjob -= 1;
1720 mtx_unlock(&sync_mtx);
1721 continue;
1722 }
1723 mtx_unlock(&sync_mtx);
1724 /*
1725 * Just sleep for a short period if time between
1726 * iterations when shutting down to allow some I/O
1727 * to happen.
1728 *
1729 * If it has taken us less than a second to process the
1730 * current work, then wait. Otherwise start right over
1731 * again. We can still lose time if any single round
1732 * takes more than two seconds, but it does not really
1733 * matter as we are just trying to generally pace the
1734 * filesystem activity.
1735 */
1736 if (syncer_state != SYNCER_RUNNING)
1737 tsleep(&dummychan, PPAUSE, "syncfnl",
1738 hz / SYNCER_SHUTDOWN_SPEEDUP);
1739 else if (time_second == starttime)
1740 tsleep(&lbolt, PPAUSE, "syncer", 0);
1741 }
1742 }
1743
1744 /*
1745 * Request the syncer daemon to speed up its work.
1746 * We never push it to speed up more than half of its
1747 * normal turn time, otherwise it could take over the cpu.
1748 */
1749 int
1750 speedup_syncer()
1751 {
1752 struct thread *td;
1753 int ret = 0;
1754
1755 td = FIRST_THREAD_IN_PROC(updateproc);
1756 sleepq_remove(td, &lbolt);
1757 mtx_lock(&sync_mtx);
1758 if (rushjob < syncdelay / 2) {
1759 rushjob += 1;
1760 stat_rush_requests += 1;
1761 ret = 1;
1762 }
1763 mtx_unlock(&sync_mtx);
1764 return (ret);
1765 }
1766
1767 /*
1768 * Tell the syncer to speed up its work and run though its work
1769 * list several times, then tell it to shut down.
1770 */
1771 static void
1772 syncer_shutdown(void *arg, int howto)
1773 {
1774 struct thread *td;
1775
1776 if (howto & RB_NOSYNC)
1777 return;
1778 td = FIRST_THREAD_IN_PROC(updateproc);
1779 sleepq_remove(td, &lbolt);
1780 mtx_lock(&sync_mtx);
1781 syncer_state = SYNCER_SHUTTING_DOWN;
1782 rushjob = 0;
1783 mtx_unlock(&sync_mtx);
1784 kproc_shutdown(arg, howto);
1785 }
1786
1787 /*
1788 * Reassign a buffer from one vnode to another.
1789 * Used to assign file specific control information
1790 * (indirect blocks) to the vnode to which they belong.
1791 */
1792 void
1793 reassignbuf(struct buf *bp)
1794 {
1795 struct vnode *vp;
1796 struct bufobj *bo;
1797 int delay;
1798 #ifdef INVARIANTS
1799 struct bufv *bv;
1800 #endif
1801
1802 vp = bp->b_vp;
1803 bo = bp->b_bufobj;
1804 ++reassignbufcalls;
1805
1806 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1807 bp, bp->b_vp, bp->b_flags);
1808 /*
1809 * B_PAGING flagged buffers cannot be reassigned because their vp
1810 * is not fully linked in.
1811 */
1812 if (bp->b_flags & B_PAGING)
1813 panic("cannot reassign paging buffer");
1814
1815 /*
1816 * Delete from old vnode list, if on one.
1817 */
1818 VI_LOCK(vp);
1819 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1820 buf_vlist_remove(bp);
1821 else
1822 panic("reassignbuf: Buffer %p not on queue.", bp);
1823 /*
1824 * If dirty, put on list of dirty buffers; otherwise insert onto list
1825 * of clean buffers.
1826 */
1827 if (bp->b_flags & B_DELWRI) {
1828 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
1829 switch (vp->v_type) {
1830 case VDIR:
1831 delay = dirdelay;
1832 break;
1833 case VCHR:
1834 delay = metadelay;
1835 break;
1836 default:
1837 delay = filedelay;
1838 }
1839 vn_syncer_add_to_worklist(bo, delay);
1840 }
1841 buf_vlist_add(bp, bo, BX_VNDIRTY);
1842 } else {
1843 buf_vlist_add(bp, bo, BX_VNCLEAN);
1844
1845 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1846 mtx_lock(&sync_mtx);
1847 LIST_REMOVE(bo, bo_synclist);
1848 syncer_worklist_len--;
1849 mtx_unlock(&sync_mtx);
1850 bo->bo_flag &= ~BO_ONWORKLST;
1851 }
1852 }
1853 #ifdef INVARIANTS
1854 bv = &bo->bo_clean;
1855 bp = TAILQ_FIRST(&bv->bv_hd);
1856 KASSERT(bp == NULL || bp->b_bufobj == bo,
1857 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1858 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1859 KASSERT(bp == NULL || bp->b_bufobj == bo,
1860 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1861 bv = &bo->bo_dirty;
1862 bp = TAILQ_FIRST(&bv->bv_hd);
1863 KASSERT(bp == NULL || bp->b_bufobj == bo,
1864 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1865 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1866 KASSERT(bp == NULL || bp->b_bufobj == bo,
1867 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1868 #endif
1869 VI_UNLOCK(vp);
1870 }
1871
1872 /*
1873 * Increment the use and hold counts on the vnode, taking care to reference
1874 * the driver's usecount if this is a chardev. The vholdl() will remove
1875 * the vnode from the free list if it is presently free. Requires the
1876 * vnode interlock and returns with it held.
1877 */
1878 static void
1879 v_incr_usecount(struct vnode *vp)
1880 {
1881
1882 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n",
1883 vp, vp->v_holdcnt, vp->v_usecount);
1884 vp->v_usecount++;
1885 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1886 dev_lock();
1887 vp->v_rdev->si_usecount++;
1888 dev_unlock();
1889 }
1890 vholdl(vp);
1891 }
1892
1893 /*
1894 * Turn a holdcnt into a use+holdcnt such that only one call to
1895 * v_decr_usecount is needed.
1896 */
1897 static void
1898 v_upgrade_usecount(struct vnode *vp)
1899 {
1900
1901 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n",
1902 vp, vp->v_holdcnt, vp->v_usecount);
1903 vp->v_usecount++;
1904 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1905 dev_lock();
1906 vp->v_rdev->si_usecount++;
1907 dev_unlock();
1908 }
1909 }
1910
1911 /*
1912 * Decrement the vnode use and hold count along with the driver's usecount
1913 * if this is a chardev. The vdropl() below releases the vnode interlock
1914 * as it may free the vnode.
1915 */
1916 static void
1917 v_decr_usecount(struct vnode *vp)
1918 {
1919
1920 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n",
1921 vp, vp->v_holdcnt, vp->v_usecount);
1922 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1923 VNASSERT(vp->v_usecount > 0, vp,
1924 ("v_decr_usecount: negative usecount"));
1925 vp->v_usecount--;
1926 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1927 dev_lock();
1928 vp->v_rdev->si_usecount--;
1929 dev_unlock();
1930 }
1931 vdropl(vp);
1932 }
1933
1934 /*
1935 * Decrement only the use count and driver use count. This is intended to
1936 * be paired with a follow on vdropl() to release the remaining hold count.
1937 * In this way we may vgone() a vnode with a 0 usecount without risk of
1938 * having it end up on a free list because the hold count is kept above 0.
1939 */
1940 static void
1941 v_decr_useonly(struct vnode *vp)
1942 {
1943
1944 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n",
1945 vp, vp->v_holdcnt, vp->v_usecount);
1946 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1947 VNASSERT(vp->v_usecount > 0, vp,
1948 ("v_decr_useonly: negative usecount"));
1949 vp->v_usecount--;
1950 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1951 dev_lock();
1952 vp->v_rdev->si_usecount--;
1953 dev_unlock();
1954 }
1955 }
1956
1957 /*
1958 * Grab a particular vnode from the free list, increment its
1959 * reference count and lock it. The vnode lock bit is set if the
1960 * vnode is being eliminated in vgone. The process is awakened
1961 * when the transition is completed, and an error returned to
1962 * indicate that the vnode is no longer usable (possibly having
1963 * been changed to a new filesystem type).
1964 */
1965 int
1966 vget(struct vnode *vp, int flags, struct thread *td)
1967 {
1968 int oweinact;
1969 int oldflags;
1970 int error;
1971
1972 error = 0;
1973 oldflags = flags;
1974 oweinact = 0;
1975 VFS_ASSERT_GIANT(vp->v_mount);
1976 if ((flags & LK_INTERLOCK) == 0)
1977 VI_LOCK(vp);
1978 /*
1979 * If the inactive call was deferred because vput() was called
1980 * with a shared lock, we have to do it here before another thread
1981 * gets a reference to data that should be dead.
1982 */
1983 if (vp->v_iflag & VI_OWEINACT) {
1984 if (flags & LK_NOWAIT) {
1985 VI_UNLOCK(vp);
1986 return (EBUSY);
1987 }
1988 flags &= ~LK_TYPE_MASK;
1989 flags |= LK_EXCLUSIVE;
1990 oweinact = 1;
1991 }
1992 vholdl(vp);
1993 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
1994 vdrop(vp);
1995 return (error);
1996 }
1997 VI_LOCK(vp);
1998 /* Upgrade our holdcnt to a usecount. */
1999 v_upgrade_usecount(vp);
2000 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2001 panic("vget: vn_lock failed to return ENOENT\n");
2002 if (oweinact) {
2003 if (vp->v_iflag & VI_OWEINACT)
2004 vinactive(vp, td);
2005 VI_UNLOCK(vp);
2006 if ((oldflags & LK_TYPE_MASK) == 0)
2007 VOP_UNLOCK(vp, 0, td);
2008 } else
2009 VI_UNLOCK(vp);
2010 return (0);
2011 }
2012
2013 /*
2014 * Increase the reference count of a vnode.
2015 */
2016 void
2017 vref(struct vnode *vp)
2018 {
2019
2020 VI_LOCK(vp);
2021 v_incr_usecount(vp);
2022 VI_UNLOCK(vp);
2023 }
2024
2025 /*
2026 * Return reference count of a vnode.
2027 *
2028 * The results of this call are only guaranteed when some mechanism other
2029 * than the VI lock is used to stop other processes from gaining references
2030 * to the vnode. This may be the case if the caller holds the only reference.
2031 * This is also useful when stale data is acceptable as race conditions may
2032 * be accounted for by some other means.
2033 */
2034 int
2035 vrefcnt(struct vnode *vp)
2036 {
2037 int usecnt;
2038
2039 VI_LOCK(vp);
2040 usecnt = vp->v_usecount;
2041 VI_UNLOCK(vp);
2042
2043 return (usecnt);
2044 }
2045
2046
2047 /*
2048 * Vnode put/release.
2049 * If count drops to zero, call inactive routine and return to freelist.
2050 */
2051 void
2052 vrele(vp)
2053 struct vnode *vp;
2054 {
2055 struct thread *td = curthread; /* XXX */
2056
2057 KASSERT(vp != NULL, ("vrele: null vp"));
2058 VFS_ASSERT_GIANT(vp->v_mount);
2059
2060 VI_LOCK(vp);
2061
2062 /* Skip this v_writecount check if we're going to panic below. */
2063 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2064 ("vrele: missed vn_close"));
2065
2066 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2067 vp->v_usecount == 1)) {
2068 v_decr_usecount(vp);
2069 return;
2070 }
2071 if (vp->v_usecount != 1) {
2072 #ifdef DIAGNOSTIC
2073 vprint("vrele: negative ref count", vp);
2074 #endif
2075 VI_UNLOCK(vp);
2076 panic("vrele: negative ref cnt");
2077 }
2078 /*
2079 * We want to hold the vnode until the inactive finishes to
2080 * prevent vgone() races. We drop the use count here and the
2081 * hold count below when we're done.
2082 */
2083 v_decr_useonly(vp);
2084 /*
2085 * We must call VOP_INACTIVE with the node locked. Mark
2086 * as VI_DOINGINACT to avoid recursion.
2087 */
2088 vp->v_iflag |= VI_OWEINACT;
2089 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) {
2090 VI_LOCK(vp);
2091 if (vp->v_usecount > 0)
2092 vp->v_iflag &= ~VI_OWEINACT;
2093 if (vp->v_iflag & VI_OWEINACT)
2094 vinactive(vp, td);
2095 VOP_UNLOCK(vp, 0, td);
2096 } else {
2097 VI_LOCK(vp);
2098 if (vp->v_usecount > 0)
2099 vp->v_iflag &= ~VI_OWEINACT;
2100 }
2101 vdropl(vp);
2102 }
2103
2104 /*
2105 * Release an already locked vnode. This give the same effects as
2106 * unlock+vrele(), but takes less time and avoids releasing and
2107 * re-aquiring the lock (as vrele() aquires the lock internally.)
2108 */
2109 void
2110 vput(vp)
2111 struct vnode *vp;
2112 {
2113 struct thread *td = curthread; /* XXX */
2114 int error;
2115
2116 KASSERT(vp != NULL, ("vput: null vp"));
2117 ASSERT_VOP_LOCKED(vp, "vput");
2118 VFS_ASSERT_GIANT(vp->v_mount);
2119 VI_LOCK(vp);
2120 /* Skip this v_writecount check if we're going to panic below. */
2121 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2122 ("vput: missed vn_close"));
2123 error = 0;
2124
2125 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2126 vp->v_usecount == 1)) {
2127 VOP_UNLOCK(vp, 0, td);
2128 v_decr_usecount(vp);
2129 return;
2130 }
2131
2132 if (vp->v_usecount != 1) {
2133 #ifdef DIAGNOSTIC
2134 vprint("vput: negative ref count", vp);
2135 #endif
2136 panic("vput: negative ref cnt");
2137 }
2138 /*
2139 * We want to hold the vnode until the inactive finishes to
2140 * prevent vgone() races. We drop the use count here and the
2141 * hold count below when we're done.
2142 */
2143 v_decr_useonly(vp);
2144 vp->v_iflag |= VI_OWEINACT;
2145 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) {
2146 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td);
2147 VI_LOCK(vp);
2148 if (error) {
2149 if (vp->v_usecount > 0)
2150 vp->v_iflag &= ~VI_OWEINACT;
2151 goto done;
2152 }
2153 }
2154 if (vp->v_usecount > 0)
2155 vp->v_iflag &= ~VI_OWEINACT;
2156 if (vp->v_iflag & VI_OWEINACT)
2157 vinactive(vp, td);
2158 VOP_UNLOCK(vp, 0, td);
2159 done:
2160 vdropl(vp);
2161 }
2162
2163 /*
2164 * Somebody doesn't want the vnode recycled.
2165 */
2166 void
2167 vhold(struct vnode *vp)
2168 {
2169
2170 VI_LOCK(vp);
2171 vholdl(vp);
2172 VI_UNLOCK(vp);
2173 }
2174
2175 void
2176 vholdl(struct vnode *vp)
2177 {
2178
2179 vp->v_holdcnt++;
2180 if (VSHOULDBUSY(vp))
2181 vbusy(vp);
2182 }
2183
2184 /*
2185 * Note that there is one less who cares about this vnode. vdrop() is the
2186 * opposite of vhold().
2187 */
2188 void
2189 vdrop(struct vnode *vp)
2190 {
2191
2192 VI_LOCK(vp);
2193 vdropl(vp);
2194 }
2195
2196 /*
2197 * Drop the hold count of the vnode. If this is the last reference to
2198 * the vnode we will free it if it has been vgone'd otherwise it is
2199 * placed on the free list.
2200 */
2201 void
2202 vdropl(struct vnode *vp)
2203 {
2204
2205 if (vp->v_holdcnt <= 0)
2206 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2207 vp->v_holdcnt--;
2208 if (vp->v_holdcnt == 0) {
2209 if (vp->v_iflag & VI_DOOMED) {
2210 vdestroy(vp);
2211 return;
2212 } else
2213 vfree(vp);
2214 }
2215 VI_UNLOCK(vp);
2216 }
2217
2218 /*
2219 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2220 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2221 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2222 * failed lock upgrade.
2223 */
2224 static void
2225 vinactive(struct vnode *vp, struct thread *td)
2226 {
2227
2228 ASSERT_VOP_LOCKED(vp, "vinactive");
2229 ASSERT_VI_LOCKED(vp, "vinactive");
2230 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2231 ("vinactive: recursed on VI_DOINGINACT"));
2232 vp->v_iflag |= VI_DOINGINACT;
2233 vp->v_iflag &= ~VI_OWEINACT;
2234 VI_UNLOCK(vp);
2235 VOP_INACTIVE(vp, td);
2236 VI_LOCK(vp);
2237 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2238 ("vinactive: lost VI_DOINGINACT"));
2239 vp->v_iflag &= ~VI_DOINGINACT;
2240 }
2241
2242 /*
2243 * Remove any vnodes in the vnode table belonging to mount point mp.
2244 *
2245 * If FORCECLOSE is not specified, there should not be any active ones,
2246 * return error if any are found (nb: this is a user error, not a
2247 * system error). If FORCECLOSE is specified, detach any active vnodes
2248 * that are found.
2249 *
2250 * If WRITECLOSE is set, only flush out regular file vnodes open for
2251 * writing.
2252 *
2253 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2254 *
2255 * `rootrefs' specifies the base reference count for the root vnode
2256 * of this filesystem. The root vnode is considered busy if its
2257 * v_usecount exceeds this value. On a successful return, vflush(, td)
2258 * will call vrele() on the root vnode exactly rootrefs times.
2259 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2260 * be zero.
2261 */
2262 #ifdef DIAGNOSTIC
2263 static int busyprt = 0; /* print out busy vnodes */
2264 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
2265 #endif
2266
2267 int
2268 vflush(mp, rootrefs, flags, td)
2269 struct mount *mp;
2270 int rootrefs;
2271 int flags;
2272 struct thread *td;
2273 {
2274 struct vnode *vp, *mvp, *rootvp = NULL;
2275 struct vattr vattr;
2276 int busy = 0, error;
2277
2278 CTR1(KTR_VFS, "vflush: mp %p", mp);
2279 if (rootrefs > 0) {
2280 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2281 ("vflush: bad args"));
2282 /*
2283 * Get the filesystem root vnode. We can vput() it
2284 * immediately, since with rootrefs > 0, it won't go away.
2285 */
2286 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0)
2287 return (error);
2288 vput(rootvp);
2289
2290 }
2291 MNT_ILOCK(mp);
2292 loop:
2293 MNT_VNODE_FOREACH(vp, mp, mvp) {
2294
2295 VI_LOCK(vp);
2296 vholdl(vp);
2297 MNT_IUNLOCK(mp);
2298 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td);
2299 if (error) {
2300 vdrop(vp);
2301 MNT_ILOCK(mp);
2302 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
2303 goto loop;
2304 }
2305 /*
2306 * Skip over a vnodes marked VV_SYSTEM.
2307 */
2308 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2309 VOP_UNLOCK(vp, 0, td);
2310 vdrop(vp);
2311 MNT_ILOCK(mp);
2312 continue;
2313 }
2314 /*
2315 * If WRITECLOSE is set, flush out unlinked but still open
2316 * files (even if open only for reading) and regular file
2317 * vnodes open for writing.
2318 */
2319 if (flags & WRITECLOSE) {
2320 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td);
2321 VI_LOCK(vp);
2322
2323 if ((vp->v_type == VNON ||
2324 (error == 0 && vattr.va_nlink > 0)) &&
2325 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2326 VOP_UNLOCK(vp, 0, td);
2327 vdropl(vp);
2328 MNT_ILOCK(mp);
2329 continue;
2330 }
2331 } else
2332 VI_LOCK(vp);
2333 /*
2334 * With v_usecount == 0, all we need to do is clear out the
2335 * vnode data structures and we are done.
2336 *
2337 * If FORCECLOSE is set, forcibly close the vnode.
2338 */
2339 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2340 VNASSERT(vp->v_usecount == 0 ||
2341 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2342 ("device VNODE %p is FORCECLOSED", vp));
2343 vgonel(vp);
2344 } else {
2345 busy++;
2346 #ifdef DIAGNOSTIC
2347 if (busyprt)
2348 vprint("vflush: busy vnode", vp);
2349 #endif
2350 }
2351 VOP_UNLOCK(vp, 0, td);
2352 vdropl(vp);
2353 MNT_ILOCK(mp);
2354 }
2355 MNT_IUNLOCK(mp);
2356 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2357 /*
2358 * If just the root vnode is busy, and if its refcount
2359 * is equal to `rootrefs', then go ahead and kill it.
2360 */
2361 VI_LOCK(rootvp);
2362 KASSERT(busy > 0, ("vflush: not busy"));
2363 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2364 ("vflush: usecount %d < rootrefs %d",
2365 rootvp->v_usecount, rootrefs));
2366 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2367 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td);
2368 vgone(rootvp);
2369 VOP_UNLOCK(rootvp, 0, td);
2370 busy = 0;
2371 } else
2372 VI_UNLOCK(rootvp);
2373 }
2374 if (busy)
2375 return (EBUSY);
2376 for (; rootrefs > 0; rootrefs--)
2377 vrele(rootvp);
2378 return (0);
2379 }
2380
2381 /*
2382 * Recycle an unused vnode to the front of the free list.
2383 */
2384 int
2385 vrecycle(struct vnode *vp, struct thread *td)
2386 {
2387 int recycled;
2388
2389 ASSERT_VOP_LOCKED(vp, "vrecycle");
2390 recycled = 0;
2391 VI_LOCK(vp);
2392 if (vp->v_usecount == 0) {
2393 recycled = 1;
2394 vgonel(vp);
2395 }
2396 VI_UNLOCK(vp);
2397 return (recycled);
2398 }
2399
2400 /*
2401 * Eliminate all activity associated with a vnode
2402 * in preparation for reuse.
2403 */
2404 void
2405 vgone(struct vnode *vp)
2406 {
2407 VI_LOCK(vp);
2408 vgonel(vp);
2409 VI_UNLOCK(vp);
2410 }
2411
2412 /*
2413 * vgone, with the vp interlock held.
2414 */
2415 void
2416 vgonel(struct vnode *vp)
2417 {
2418 struct thread *td;
2419 int oweinact;
2420 int active;
2421 struct mount *mp;
2422
2423 CTR1(KTR_VFS, "vgonel: vp %p", vp);
2424 ASSERT_VOP_LOCKED(vp, "vgonel");
2425 ASSERT_VI_LOCKED(vp, "vgonel");
2426 #if 0
2427 /* XXX Need to fix ttyvp before I enable this. */
2428 VNASSERT(vp->v_holdcnt, vp,
2429 ("vgonel: vp %p has no reference.", vp));
2430 #endif
2431 td = curthread;
2432
2433 /*
2434 * Don't vgonel if we're already doomed.
2435 */
2436 if (vp->v_iflag & VI_DOOMED)
2437 return;
2438 vp->v_iflag |= VI_DOOMED;
2439 /*
2440 * Check to see if the vnode is in use. If so, we have to call
2441 * VOP_CLOSE() and VOP_INACTIVE().
2442 */
2443 active = vp->v_usecount;
2444 oweinact = (vp->v_iflag & VI_OWEINACT);
2445 VI_UNLOCK(vp);
2446 /*
2447 * Clean out any buffers associated with the vnode.
2448 * If the flush fails, just toss the buffers.
2449 */
2450 mp = NULL;
2451 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2452 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2453 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0)
2454 vinvalbuf(vp, 0, td, 0, 0);
2455
2456 /*
2457 * If purging an active vnode, it must be closed and
2458 * deactivated before being reclaimed.
2459 */
2460 if (active)
2461 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2462 if (oweinact || active) {
2463 VI_LOCK(vp);
2464 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2465 vinactive(vp, td);
2466 VI_UNLOCK(vp);
2467 }
2468 /*
2469 * Reclaim the vnode.
2470 */
2471 if (VOP_RECLAIM(vp, td))
2472 panic("vgone: cannot reclaim");
2473 if (mp != NULL)
2474 vn_finished_secondary_write(mp);
2475 VNASSERT(vp->v_object == NULL, vp,
2476 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2477 /*
2478 * Delete from old mount point vnode list.
2479 */
2480 delmntque(vp);
2481 cache_purge(vp);
2482 /*
2483 * Done with purge, reset to the standard lock and invalidate
2484 * the vnode.
2485 */
2486 VI_LOCK(vp);
2487 vp->v_vnlock = &vp->v_lock;
2488 vp->v_op = &dead_vnodeops;
2489 vp->v_tag = "none";
2490 vp->v_type = VBAD;
2491 }
2492
2493 /*
2494 * Calculate the total number of references to a special device.
2495 */
2496 int
2497 vcount(vp)
2498 struct vnode *vp;
2499 {
2500 int count;
2501
2502 dev_lock();
2503 count = vp->v_rdev->si_usecount;
2504 dev_unlock();
2505 return (count);
2506 }
2507
2508 /*
2509 * Same as above, but using the struct cdev *as argument
2510 */
2511 int
2512 count_dev(dev)
2513 struct cdev *dev;
2514 {
2515 int count;
2516
2517 dev_lock();
2518 count = dev->si_usecount;
2519 dev_unlock();
2520 return(count);
2521 }
2522
2523 /*
2524 * Print out a description of a vnode.
2525 */
2526 static char *typename[] =
2527 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2528 "VMARKER"};
2529
2530 void
2531 vn_printf(struct vnode *vp, const char *fmt, ...)
2532 {
2533 va_list ap;
2534 char buf[96];
2535
2536 va_start(ap, fmt);
2537 vprintf(fmt, ap);
2538 va_end(ap);
2539 printf("%p: ", (void *)vp);
2540 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2541 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2542 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2543 buf[0] = '\0';
2544 buf[1] = '\0';
2545 if (vp->v_vflag & VV_ROOT)
2546 strcat(buf, "|VV_ROOT");
2547 if (vp->v_vflag & VV_TEXT)
2548 strcat(buf, "|VV_TEXT");
2549 if (vp->v_vflag & VV_SYSTEM)
2550 strcat(buf, "|VV_SYSTEM");
2551 if (vp->v_iflag & VI_DOOMED)
2552 strcat(buf, "|VI_DOOMED");
2553 if (vp->v_iflag & VI_FREE)
2554 strcat(buf, "|VI_FREE");
2555 printf(" flags (%s)\n", buf + 1);
2556 if (mtx_owned(VI_MTX(vp)))
2557 printf(" VI_LOCKed");
2558 if (vp->v_object != NULL)
2559 printf(" v_object %p ref %d pages %d\n",
2560 vp->v_object, vp->v_object->ref_count,
2561 vp->v_object->resident_page_count);
2562 printf(" ");
2563 lockmgr_printinfo(vp->v_vnlock);
2564 printf("\n");
2565 if (vp->v_data != NULL)
2566 VOP_PRINT(vp);
2567 }
2568
2569 #ifdef DDB
2570 /*
2571 * List all of the locked vnodes in the system.
2572 * Called when debugging the kernel.
2573 */
2574 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2575 {
2576 struct mount *mp, *nmp;
2577 struct vnode *vp;
2578
2579 /*
2580 * Note: because this is DDB, we can't obey the locking semantics
2581 * for these structures, which means we could catch an inconsistent
2582 * state and dereference a nasty pointer. Not much to be done
2583 * about that.
2584 */
2585 printf("Locked vnodes\n");
2586 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2587 nmp = TAILQ_NEXT(mp, mnt_list);
2588 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2589 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL))
2590 vprint("", vp);
2591 }
2592 nmp = TAILQ_NEXT(mp, mnt_list);
2593 }
2594 }
2595
2596 /*
2597 * Show details about the given vnode.
2598 */
2599 DB_SHOW_COMMAND(vnode, db_show_vnode)
2600 {
2601 struct vnode *vp;
2602
2603 if (!have_addr)
2604 return;
2605 vp = (struct vnode *)addr;
2606 vn_printf(vp, "vnode ");
2607 }
2608 #endif /* DDB */
2609
2610 /*
2611 * Fill in a struct xvfsconf based on a struct vfsconf.
2612 */
2613 static void
2614 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
2615 {
2616
2617 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
2618 xvfsp->vfc_typenum = vfsp->vfc_typenum;
2619 xvfsp->vfc_refcount = vfsp->vfc_refcount;
2620 xvfsp->vfc_flags = vfsp->vfc_flags;
2621 /*
2622 * These are unused in userland, we keep them
2623 * to not break binary compatibility.
2624 */
2625 xvfsp->vfc_vfsops = NULL;
2626 xvfsp->vfc_next = NULL;
2627 }
2628
2629 /*
2630 * Top level filesystem related information gathering.
2631 */
2632 static int
2633 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
2634 {
2635 struct vfsconf *vfsp;
2636 struct xvfsconf xvfsp;
2637 int error;
2638
2639 error = 0;
2640 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2641 bzero(&xvfsp, sizeof(xvfsp));
2642 vfsconf2x(vfsp, &xvfsp);
2643 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
2644 if (error)
2645 break;
2646 }
2647 return (error);
2648 }
2649
2650 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist,
2651 "S,xvfsconf", "List of all configured filesystems");
2652
2653 #ifndef BURN_BRIDGES
2654 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
2655
2656 static int
2657 vfs_sysctl(SYSCTL_HANDLER_ARGS)
2658 {
2659 int *name = (int *)arg1 - 1; /* XXX */
2660 u_int namelen = arg2 + 1; /* XXX */
2661 struct vfsconf *vfsp;
2662 struct xvfsconf xvfsp;
2663
2664 printf("WARNING: userland calling deprecated sysctl, "
2665 "please rebuild world\n");
2666
2667 #if 1 || defined(COMPAT_PRELITE2)
2668 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
2669 if (namelen == 1)
2670 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
2671 #endif
2672
2673 switch (name[1]) {
2674 case VFS_MAXTYPENUM:
2675 if (namelen != 2)
2676 return (ENOTDIR);
2677 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
2678 case VFS_CONF:
2679 if (namelen != 3)
2680 return (ENOTDIR); /* overloaded */
2681 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
2682 if (vfsp->vfc_typenum == name[2])
2683 break;
2684 if (vfsp == NULL)
2685 return (EOPNOTSUPP);
2686 bzero(&xvfsp, sizeof(xvfsp));
2687 vfsconf2x(vfsp, &xvfsp);
2688 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
2689 }
2690 return (EOPNOTSUPP);
2691 }
2692
2693 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
2694 vfs_sysctl, "Generic filesystem");
2695
2696 #if 1 || defined(COMPAT_PRELITE2)
2697
2698 static int
2699 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
2700 {
2701 int error;
2702 struct vfsconf *vfsp;
2703 struct ovfsconf ovfs;
2704
2705 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2706 bzero(&ovfs, sizeof(ovfs));
2707 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
2708 strcpy(ovfs.vfc_name, vfsp->vfc_name);
2709 ovfs.vfc_index = vfsp->vfc_typenum;
2710 ovfs.vfc_refcount = vfsp->vfc_refcount;
2711 ovfs.vfc_flags = vfsp->vfc_flags;
2712 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
2713 if (error)
2714 return error;
2715 }
2716 return 0;
2717 }
2718
2719 #endif /* 1 || COMPAT_PRELITE2 */
2720 #endif /* !BURN_BRIDGES */
2721
2722 #define KINFO_VNODESLOP 10
2723 #ifdef notyet
2724 /*
2725 * Dump vnode list (via sysctl).
2726 */
2727 /* ARGSUSED */
2728 static int
2729 sysctl_vnode(SYSCTL_HANDLER_ARGS)
2730 {
2731 struct xvnode *xvn;
2732 struct thread *td = req->td;
2733 struct mount *mp;
2734 struct vnode *vp;
2735 int error, len, n;
2736
2737 /*
2738 * Stale numvnodes access is not fatal here.
2739 */
2740 req->lock = 0;
2741 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
2742 if (!req->oldptr)
2743 /* Make an estimate */
2744 return (SYSCTL_OUT(req, 0, len));
2745
2746 error = sysctl_wire_old_buffer(req, 0);
2747 if (error != 0)
2748 return (error);
2749 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
2750 n = 0;
2751 mtx_lock(&mountlist_mtx);
2752 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2753 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td))
2754 continue;
2755 MNT_ILOCK(mp);
2756 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2757 if (n == len)
2758 break;
2759 vref(vp);
2760 xvn[n].xv_size = sizeof *xvn;
2761 xvn[n].xv_vnode = vp;
2762 xvn[n].xv_id = 0; /* XXX compat */
2763 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
2764 XV_COPY(usecount);
2765 XV_COPY(writecount);
2766 XV_COPY(holdcnt);
2767 XV_COPY(mount);
2768 XV_COPY(numoutput);
2769 XV_COPY(type);
2770 #undef XV_COPY
2771 xvn[n].xv_flag = vp->v_vflag;
2772
2773 switch (vp->v_type) {
2774 case VREG:
2775 case VDIR:
2776 case VLNK:
2777 break;
2778 case VBLK:
2779 case VCHR:
2780 if (vp->v_rdev == NULL) {
2781 vrele(vp);
2782 continue;
2783 }
2784 xvn[n].xv_dev = dev2udev(vp->v_rdev);
2785 break;
2786 case VSOCK:
2787 xvn[n].xv_socket = vp->v_socket;
2788 break;
2789 case VFIFO:
2790 xvn[n].xv_fifo = vp->v_fifoinfo;
2791 break;
2792 case VNON:
2793 case VBAD:
2794 default:
2795 /* shouldn't happen? */
2796 vrele(vp);
2797 continue;
2798 }
2799 vrele(vp);
2800 ++n;
2801 }
2802 MNT_IUNLOCK(mp);
2803 mtx_lock(&mountlist_mtx);
2804 vfs_unbusy(mp, td);
2805 if (n == len)
2806 break;
2807 }
2808 mtx_unlock(&mountlist_mtx);
2809
2810 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
2811 free(xvn, M_TEMP);
2812 return (error);
2813 }
2814
2815 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
2816 0, 0, sysctl_vnode, "S,xvnode", "");
2817 #endif
2818
2819 /*
2820 * Unmount all filesystems. The list is traversed in reverse order
2821 * of mounting to avoid dependencies.
2822 */
2823 void
2824 vfs_unmountall()
2825 {
2826 struct mount *mp;
2827 struct thread *td;
2828 int error;
2829
2830 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
2831 td = curthread;
2832 /*
2833 * Since this only runs when rebooting, it is not interlocked.
2834 */
2835 while(!TAILQ_EMPTY(&mountlist)) {
2836 mp = TAILQ_LAST(&mountlist, mntlist);
2837 error = dounmount(mp, MNT_FORCE, td);
2838 if (error) {
2839 TAILQ_REMOVE(&mountlist, mp, mnt_list);
2840 /*
2841 * XXX: Due to the way in which we mount the root
2842 * file system off of devfs, devfs will generate a
2843 * "busy" warning when we try to unmount it before
2844 * the root. Don't print a warning as a result in
2845 * order to avoid false positive errors that may
2846 * cause needless upset.
2847 */
2848 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
2849 printf("unmount of %s failed (",
2850 mp->mnt_stat.f_mntonname);
2851 if (error == EBUSY)
2852 printf("BUSY)\n");
2853 else
2854 printf("%d)\n", error);
2855 }
2856 } else {
2857 /* The unmount has removed mp from the mountlist */
2858 }
2859 }
2860 }
2861
2862 /*
2863 * perform msync on all vnodes under a mount point
2864 * the mount point must be locked.
2865 */
2866 void
2867 vfs_msync(struct mount *mp, int flags)
2868 {
2869 struct vnode *vp, *mvp;
2870 struct vm_object *obj;
2871
2872 MNT_ILOCK(mp);
2873 MNT_VNODE_FOREACH(vp, mp, mvp) {
2874 VI_LOCK(vp);
2875 if ((vp->v_iflag & VI_OBJDIRTY) &&
2876 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
2877 MNT_IUNLOCK(mp);
2878 if (!vget(vp,
2879 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
2880 curthread)) {
2881 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
2882 vput(vp);
2883 MNT_ILOCK(mp);
2884 continue;
2885 }
2886
2887 obj = vp->v_object;
2888 if (obj != NULL) {
2889 VM_OBJECT_LOCK(obj);
2890 vm_object_page_clean(obj, 0, 0,
2891 flags == MNT_WAIT ?
2892 OBJPC_SYNC : OBJPC_NOSYNC);
2893 VM_OBJECT_UNLOCK(obj);
2894 }
2895 vput(vp);
2896 }
2897 MNT_ILOCK(mp);
2898 } else
2899 VI_UNLOCK(vp);
2900 }
2901 MNT_IUNLOCK(mp);
2902 }
2903
2904 /*
2905 * Mark a vnode as free, putting it up for recycling.
2906 */
2907 static void
2908 vfree(struct vnode *vp)
2909 {
2910
2911 CTR1(KTR_VFS, "vfree vp %p", vp);
2912 ASSERT_VI_LOCKED(vp, "vfree");
2913 mtx_lock(&vnode_free_list_mtx);
2914 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed."));
2915 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free"));
2916 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't"));
2917 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp,
2918 ("vfree: Freeing doomed vnode"));
2919 if (vp->v_iflag & VI_AGE) {
2920 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
2921 } else {
2922 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
2923 }
2924 freevnodes++;
2925 vp->v_iflag &= ~VI_AGE;
2926 vp->v_iflag |= VI_FREE;
2927 mtx_unlock(&vnode_free_list_mtx);
2928 }
2929
2930 /*
2931 * Opposite of vfree() - mark a vnode as in use.
2932 */
2933 static void
2934 vbusy(struct vnode *vp)
2935 {
2936 CTR1(KTR_VFS, "vbusy vp %p", vp);
2937 ASSERT_VI_LOCKED(vp, "vbusy");
2938 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
2939 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed."));
2940
2941 mtx_lock(&vnode_free_list_mtx);
2942 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
2943 freevnodes--;
2944 vp->v_iflag &= ~(VI_FREE|VI_AGE);
2945 mtx_unlock(&vnode_free_list_mtx);
2946 }
2947
2948 /*
2949 * Initalize per-vnode helper structure to hold poll-related state.
2950 */
2951 void
2952 v_addpollinfo(struct vnode *vp)
2953 {
2954 struct vpollinfo *vi;
2955
2956 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
2957 if (vp->v_pollinfo != NULL) {
2958 uma_zfree(vnodepoll_zone, vi);
2959 return;
2960 }
2961 vp->v_pollinfo = vi;
2962 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
2963 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock,
2964 vfs_knlunlock, vfs_knllocked);
2965 }
2966
2967 /*
2968 * Record a process's interest in events which might happen to
2969 * a vnode. Because poll uses the historic select-style interface
2970 * internally, this routine serves as both the ``check for any
2971 * pending events'' and the ``record my interest in future events''
2972 * functions. (These are done together, while the lock is held,
2973 * to avoid race conditions.)
2974 */
2975 int
2976 vn_pollrecord(vp, td, events)
2977 struct vnode *vp;
2978 struct thread *td;
2979 short events;
2980 {
2981
2982 if (vp->v_pollinfo == NULL)
2983 v_addpollinfo(vp);
2984 mtx_lock(&vp->v_pollinfo->vpi_lock);
2985 if (vp->v_pollinfo->vpi_revents & events) {
2986 /*
2987 * This leaves events we are not interested
2988 * in available for the other process which
2989 * which presumably had requested them
2990 * (otherwise they would never have been
2991 * recorded).
2992 */
2993 events &= vp->v_pollinfo->vpi_revents;
2994 vp->v_pollinfo->vpi_revents &= ~events;
2995
2996 mtx_unlock(&vp->v_pollinfo->vpi_lock);
2997 return events;
2998 }
2999 vp->v_pollinfo->vpi_events |= events;
3000 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3001 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3002 return 0;
3003 }
3004
3005 /*
3006 * Routine to create and manage a filesystem syncer vnode.
3007 */
3008 #define sync_close ((int (*)(struct vop_close_args *))nullop)
3009 static int sync_fsync(struct vop_fsync_args *);
3010 static int sync_inactive(struct vop_inactive_args *);
3011 static int sync_reclaim(struct vop_reclaim_args *);
3012
3013 static struct vop_vector sync_vnodeops = {
3014 .vop_bypass = VOP_EOPNOTSUPP,
3015 .vop_close = sync_close, /* close */
3016 .vop_fsync = sync_fsync, /* fsync */
3017 .vop_inactive = sync_inactive, /* inactive */
3018 .vop_reclaim = sync_reclaim, /* reclaim */
3019 .vop_lock = vop_stdlock, /* lock */
3020 .vop_unlock = vop_stdunlock, /* unlock */
3021 .vop_islocked = vop_stdislocked, /* islocked */
3022 };
3023
3024 /*
3025 * Create a new filesystem syncer vnode for the specified mount point.
3026 */
3027 int
3028 vfs_allocate_syncvnode(mp)
3029 struct mount *mp;
3030 {
3031 struct vnode *vp;
3032 static long start, incr, next;
3033 int error;
3034
3035 /* Allocate a new vnode */
3036 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) {
3037 mp->mnt_syncer = NULL;
3038 return (error);
3039 }
3040 vp->v_type = VNON;
3041 /*
3042 * Place the vnode onto the syncer worklist. We attempt to
3043 * scatter them about on the list so that they will go off
3044 * at evenly distributed times even if all the filesystems
3045 * are mounted at once.
3046 */
3047 next += incr;
3048 if (next == 0 || next > syncer_maxdelay) {
3049 start /= 2;
3050 incr /= 2;
3051 if (start == 0) {
3052 start = syncer_maxdelay / 2;
3053 incr = syncer_maxdelay;
3054 }
3055 next = start;
3056 }
3057 VI_LOCK(vp);
3058 vn_syncer_add_to_worklist(&vp->v_bufobj,
3059 syncdelay > 0 ? next % syncdelay : 0);
3060 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
3061 mtx_lock(&sync_mtx);
3062 sync_vnode_count++;
3063 mtx_unlock(&sync_mtx);
3064 VI_UNLOCK(vp);
3065 mp->mnt_syncer = vp;
3066 return (0);
3067 }
3068
3069 /*
3070 * Do a lazy sync of the filesystem.
3071 */
3072 static int
3073 sync_fsync(ap)
3074 struct vop_fsync_args /* {
3075 struct vnode *a_vp;
3076 struct ucred *a_cred;
3077 int a_waitfor;
3078 struct thread *a_td;
3079 } */ *ap;
3080 {
3081 struct vnode *syncvp = ap->a_vp;
3082 struct mount *mp = syncvp->v_mount;
3083 struct thread *td = ap->a_td;
3084 int error, asyncflag;
3085 struct bufobj *bo;
3086
3087 /*
3088 * We only need to do something if this is a lazy evaluation.
3089 */
3090 if (ap->a_waitfor != MNT_LAZY)
3091 return (0);
3092
3093 /*
3094 * Move ourselves to the back of the sync list.
3095 */
3096 bo = &syncvp->v_bufobj;
3097 BO_LOCK(bo);
3098 vn_syncer_add_to_worklist(bo, syncdelay);
3099 BO_UNLOCK(bo);
3100
3101 /*
3102 * Walk the list of vnodes pushing all that are dirty and
3103 * not already on the sync list.
3104 */
3105 mtx_lock(&mountlist_mtx);
3106 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) {
3107 mtx_unlock(&mountlist_mtx);
3108 return (0);
3109 }
3110 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
3111 vfs_unbusy(mp, td);
3112 return (0);
3113 }
3114 MNT_ILOCK(mp);
3115 asyncflag = mp->mnt_flag & MNT_ASYNC;
3116 mp->mnt_flag &= ~MNT_ASYNC;
3117 MNT_IUNLOCK(mp);
3118 vfs_msync(mp, MNT_NOWAIT);
3119 error = VFS_SYNC(mp, MNT_LAZY, td);
3120 MNT_ILOCK(mp);
3121 if (asyncflag)
3122 mp->mnt_flag |= MNT_ASYNC;
3123 MNT_IUNLOCK(mp);
3124 vn_finished_write(mp);
3125 vfs_unbusy(mp, td);
3126 return (error);
3127 }
3128
3129 /*
3130 * The syncer vnode is no referenced.
3131 */
3132 static int
3133 sync_inactive(ap)
3134 struct vop_inactive_args /* {
3135 struct vnode *a_vp;
3136 struct thread *a_td;
3137 } */ *ap;
3138 {
3139
3140 vgone(ap->a_vp);
3141 return (0);
3142 }
3143
3144 /*
3145 * The syncer vnode is no longer needed and is being decommissioned.
3146 *
3147 * Modifications to the worklist must be protected by sync_mtx.
3148 */
3149 static int
3150 sync_reclaim(ap)
3151 struct vop_reclaim_args /* {
3152 struct vnode *a_vp;
3153 } */ *ap;
3154 {
3155 struct vnode *vp = ap->a_vp;
3156 struct bufobj *bo;
3157
3158 VI_LOCK(vp);
3159 bo = &vp->v_bufobj;
3160 vp->v_mount->mnt_syncer = NULL;
3161 if (bo->bo_flag & BO_ONWORKLST) {
3162 mtx_lock(&sync_mtx);
3163 LIST_REMOVE(bo, bo_synclist);
3164 syncer_worklist_len--;
3165 sync_vnode_count--;
3166 mtx_unlock(&sync_mtx);
3167 bo->bo_flag &= ~BO_ONWORKLST;
3168 }
3169 VI_UNLOCK(vp);
3170
3171 return (0);
3172 }
3173
3174 /*
3175 * Check if vnode represents a disk device
3176 */
3177 int
3178 vn_isdisk(vp, errp)
3179 struct vnode *vp;
3180 int *errp;
3181 {
3182 int error;
3183
3184 error = 0;
3185 dev_lock();
3186 if (vp->v_type != VCHR)
3187 error = ENOTBLK;
3188 else if (vp->v_rdev == NULL)
3189 error = ENXIO;
3190 else if (vp->v_rdev->si_devsw == NULL)
3191 error = ENXIO;
3192 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
3193 error = ENOTBLK;
3194 dev_unlock();
3195 if (errp != NULL)
3196 *errp = error;
3197 return (error == 0);
3198 }
3199
3200 /*
3201 * Common filesystem object access control check routine. Accepts a
3202 * vnode's type, "mode", uid and gid, requested access mode, credentials,
3203 * and optional call-by-reference privused argument allowing vaccess()
3204 * to indicate to the caller whether privilege was used to satisfy the
3205 * request (obsoleted). Returns 0 on success, or an errno on failure.
3206 */
3207 int
3208 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused)
3209 enum vtype type;
3210 mode_t file_mode;
3211 uid_t file_uid;
3212 gid_t file_gid;
3213 mode_t acc_mode;
3214 struct ucred *cred;
3215 int *privused;
3216 {
3217 mode_t dac_granted;
3218 #ifdef CAPABILITIES
3219 mode_t cap_granted;
3220 #endif
3221
3222 /*
3223 * Look for a normal, non-privileged way to access the file/directory
3224 * as requested. If it exists, go with that.
3225 */
3226
3227 if (privused != NULL)
3228 *privused = 0;
3229
3230 dac_granted = 0;
3231
3232 /* Check the owner. */
3233 if (cred->cr_uid == file_uid) {
3234 dac_granted |= VADMIN;
3235 if (file_mode & S_IXUSR)
3236 dac_granted |= VEXEC;
3237 if (file_mode & S_IRUSR)
3238 dac_granted |= VREAD;
3239 if (file_mode & S_IWUSR)
3240 dac_granted |= (VWRITE | VAPPEND);
3241
3242 if ((acc_mode & dac_granted) == acc_mode)
3243 return (0);
3244
3245 goto privcheck;
3246 }
3247
3248 /* Otherwise, check the groups (first match) */
3249 if (groupmember(file_gid, cred)) {
3250 if (file_mode & S_IXGRP)
3251 dac_granted |= VEXEC;
3252 if (file_mode & S_IRGRP)
3253 dac_granted |= VREAD;
3254 if (file_mode & S_IWGRP)
3255 dac_granted |= (VWRITE | VAPPEND);
3256
3257 if ((acc_mode & dac_granted) == acc_mode)
3258 return (0);
3259
3260 goto privcheck;
3261 }
3262
3263 /* Otherwise, check everyone else. */
3264 if (file_mode & S_IXOTH)
3265 dac_granted |= VEXEC;
3266 if (file_mode & S_IROTH)
3267 dac_granted |= VREAD;
3268 if (file_mode & S_IWOTH)
3269 dac_granted |= (VWRITE | VAPPEND);
3270 if ((acc_mode & dac_granted) == acc_mode)
3271 return (0);
3272
3273 privcheck:
3274 if (!suser_cred(cred, SUSER_ALLOWJAIL)) {
3275 /* XXX audit: privilege used */
3276 if (privused != NULL)
3277 *privused = 1;
3278 return (0);
3279 }
3280
3281 #ifdef CAPABILITIES
3282 /*
3283 * Build a capability mask to determine if the set of capabilities
3284 * satisfies the requirements when combined with the granted mask
3285 * from above.
3286 * For each capability, if the capability is required, bitwise
3287 * or the request type onto the cap_granted mask.
3288 */
3289 cap_granted = 0;
3290
3291 if (type == VDIR) {
3292 /*
3293 * For directories, use CAP_DAC_READ_SEARCH to satisfy
3294 * VEXEC requests, instead of CAP_DAC_EXECUTE.
3295 */
3296 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3297 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL))
3298 cap_granted |= VEXEC;
3299 } else {
3300 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3301 !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL))
3302 cap_granted |= VEXEC;
3303 }
3304
3305 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) &&
3306 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL))
3307 cap_granted |= VREAD;
3308
3309 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
3310 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL))
3311 cap_granted |= (VWRITE | VAPPEND);
3312
3313 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
3314 !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL))
3315 cap_granted |= VADMIN;
3316
3317 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) {
3318 /* XXX audit: privilege used */
3319 if (privused != NULL)
3320 *privused = 1;
3321 return (0);
3322 }
3323 #endif
3324
3325 return ((acc_mode & VADMIN) ? EPERM : EACCES);
3326 }
3327
3328 /*
3329 * Credential check based on process requesting service, and per-attribute
3330 * permissions.
3331 */
3332 int
3333 extattr_check_cred(struct vnode *vp, int attrnamespace,
3334 struct ucred *cred, struct thread *td, int access)
3335 {
3336
3337 /*
3338 * Kernel-invoked always succeeds.
3339 */
3340 if (cred == NOCRED)
3341 return (0);
3342
3343 /*
3344 * Do not allow privileged processes in jail to directly
3345 * manipulate system attributes.
3346 *
3347 * XXX What capability should apply here?
3348 * Probably CAP_SYS_SETFFLAG.
3349 */
3350 switch (attrnamespace) {
3351 case EXTATTR_NAMESPACE_SYSTEM:
3352 /* Potentially should be: return (EPERM); */
3353 return (suser_cred(cred, 0));
3354 case EXTATTR_NAMESPACE_USER:
3355 return (VOP_ACCESS(vp, access, cred, td));
3356 default:
3357 return (EPERM);
3358 }
3359 }
3360
3361 #ifdef DEBUG_VFS_LOCKS
3362 /*
3363 * This only exists to supress warnings from unlocked specfs accesses. It is
3364 * no longer ok to have an unlocked VFS.
3365 */
3366 #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD)
3367
3368 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
3369 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, "");
3370
3371 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
3372 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, "");
3373
3374 int vfs_badlock_print = 1; /* Print lock violations. */
3375 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, "");
3376
3377 #ifdef KDB
3378 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
3379 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, "");
3380 #endif
3381
3382 static void
3383 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
3384 {
3385
3386 #ifdef KDB
3387 if (vfs_badlock_backtrace)
3388 kdb_backtrace();
3389 #endif
3390 if (vfs_badlock_print)
3391 printf("%s: %p %s\n", str, (void *)vp, msg);
3392 if (vfs_badlock_ddb)
3393 kdb_enter("lock violation");
3394 }
3395
3396 void
3397 assert_vi_locked(struct vnode *vp, const char *str)
3398 {
3399
3400 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
3401 vfs_badlock("interlock is not locked but should be", str, vp);
3402 }
3403
3404 void
3405 assert_vi_unlocked(struct vnode *vp, const char *str)
3406 {
3407
3408 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
3409 vfs_badlock("interlock is locked but should not be", str, vp);
3410 }
3411
3412 void
3413 assert_vop_locked(struct vnode *vp, const char *str)
3414 {
3415
3416 if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0)
3417 vfs_badlock("is not locked but should be", str, vp);
3418 }
3419
3420 void
3421 assert_vop_unlocked(struct vnode *vp, const char *str)
3422 {
3423
3424 if (vp && !IGNORE_LOCK(vp) &&
3425 VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE)
3426 vfs_badlock("is locked but should not be", str, vp);
3427 }
3428
3429 void
3430 assert_vop_elocked(struct vnode *vp, const char *str)
3431 {
3432
3433 if (vp && !IGNORE_LOCK(vp) &&
3434 VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE)
3435 vfs_badlock("is not exclusive locked but should be", str, vp);
3436 }
3437
3438 #if 0
3439 void
3440 assert_vop_elocked_other(struct vnode *vp, const char *str)
3441 {
3442
3443 if (vp && !IGNORE_LOCK(vp) &&
3444 VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER)
3445 vfs_badlock("is not exclusive locked by another thread",
3446 str, vp);
3447 }
3448
3449 void
3450 assert_vop_slocked(struct vnode *vp, const char *str)
3451 {
3452
3453 if (vp && !IGNORE_LOCK(vp) &&
3454 VOP_ISLOCKED(vp, curthread) != LK_SHARED)
3455 vfs_badlock("is not locked shared but should be", str, vp);
3456 }
3457 #endif /* 0 */
3458 #endif /* DEBUG_VFS_LOCKS */
3459
3460 void
3461 vop_rename_pre(void *ap)
3462 {
3463 struct vop_rename_args *a = ap;
3464
3465 #ifdef DEBUG_VFS_LOCKS
3466 if (a->a_tvp)
3467 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
3468 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
3469 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
3470 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
3471
3472 /* Check the source (from). */
3473 if (a->a_tdvp != a->a_fdvp)
3474 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
3475 if (a->a_tvp != a->a_fvp)
3476 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked");
3477
3478 /* Check the target. */
3479 if (a->a_tvp)
3480 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
3481 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
3482 #endif
3483 if (a->a_tdvp != a->a_fdvp)
3484 vhold(a->a_fdvp);
3485 if (a->a_tvp != a->a_fvp)
3486 vhold(a->a_fvp);
3487 vhold(a->a_tdvp);
3488 if (a->a_tvp)
3489 vhold(a->a_tvp);
3490 }
3491
3492 void
3493 vop_strategy_pre(void *ap)
3494 {
3495 #ifdef DEBUG_VFS_LOCKS
3496 struct vop_strategy_args *a;
3497 struct buf *bp;
3498
3499 a = ap;
3500 bp = a->a_bp;
3501
3502 /*
3503 * Cluster ops lock their component buffers but not the IO container.
3504 */
3505 if ((bp->b_flags & B_CLUSTER) != 0)
3506 return;
3507
3508 if (BUF_REFCNT(bp) < 1) {
3509 if (vfs_badlock_print)
3510 printf(
3511 "VOP_STRATEGY: bp is not locked but should be\n");
3512 if (vfs_badlock_ddb)
3513 kdb_enter("lock violation");
3514 }
3515 #endif
3516 }
3517
3518 void
3519 vop_lookup_pre(void *ap)
3520 {
3521 #ifdef DEBUG_VFS_LOCKS
3522 struct vop_lookup_args *a;
3523 struct vnode *dvp;
3524
3525 a = ap;
3526 dvp = a->a_dvp;
3527 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3528 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3529 #endif
3530 }
3531
3532 void
3533 vop_lookup_post(void *ap, int rc)
3534 {
3535 #ifdef DEBUG_VFS_LOCKS
3536 struct vop_lookup_args *a;
3537 struct vnode *dvp;
3538 struct vnode *vp;
3539
3540 a = ap;
3541 dvp = a->a_dvp;
3542 vp = *(a->a_vpp);
3543
3544 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3545 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3546
3547 if (!rc)
3548 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)");
3549 #endif
3550 }
3551
3552 void
3553 vop_lock_pre(void *ap)
3554 {
3555 #ifdef DEBUG_VFS_LOCKS
3556 struct vop_lock_args *a = ap;
3557
3558 if ((a->a_flags & LK_INTERLOCK) == 0)
3559 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3560 else
3561 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
3562 #endif
3563 }
3564
3565 void
3566 vop_lock_post(void *ap, int rc)
3567 {
3568 #ifdef DEBUG_VFS_LOCKS
3569 struct vop_lock_args *a = ap;
3570
3571 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3572 if (rc == 0)
3573 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
3574 #endif
3575 }
3576
3577 void
3578 vop_unlock_pre(void *ap)
3579 {
3580 #ifdef DEBUG_VFS_LOCKS
3581 struct vop_unlock_args *a = ap;
3582
3583 if (a->a_flags & LK_INTERLOCK)
3584 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
3585 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
3586 #endif
3587 }
3588
3589 void
3590 vop_unlock_post(void *ap, int rc)
3591 {
3592 #ifdef DEBUG_VFS_LOCKS
3593 struct vop_unlock_args *a = ap;
3594
3595 if (a->a_flags & LK_INTERLOCK)
3596 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
3597 #endif
3598 }
3599
3600 void
3601 vop_create_post(void *ap, int rc)
3602 {
3603 struct vop_create_args *a = ap;
3604
3605 if (!rc)
3606 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3607 }
3608
3609 void
3610 vop_link_post(void *ap, int rc)
3611 {
3612 struct vop_link_args *a = ap;
3613
3614 if (!rc) {
3615 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
3616 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
3617 }
3618 }
3619
3620 void
3621 vop_mkdir_post(void *ap, int rc)
3622 {
3623 struct vop_mkdir_args *a = ap;
3624
3625 if (!rc)
3626 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
3627 }
3628
3629 void
3630 vop_mknod_post(void *ap, int rc)
3631 {
3632 struct vop_mknod_args *a = ap;
3633
3634 if (!rc)
3635 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3636 }
3637
3638 void
3639 vop_remove_post(void *ap, int rc)
3640 {
3641 struct vop_remove_args *a = ap;
3642
3643 if (!rc) {
3644 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3645 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
3646 }
3647 }
3648
3649 void
3650 vop_rename_post(void *ap, int rc)
3651 {
3652 struct vop_rename_args *a = ap;
3653
3654 if (!rc) {
3655 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE);
3656 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE);
3657 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
3658 if (a->a_tvp)
3659 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
3660 }
3661 if (a->a_tdvp != a->a_fdvp)
3662 vdrop(a->a_fdvp);
3663 if (a->a_tvp != a->a_fvp)
3664 vdrop(a->a_fvp);
3665 vdrop(a->a_tdvp);
3666 if (a->a_tvp)
3667 vdrop(a->a_tvp);
3668 }
3669
3670 void
3671 vop_rmdir_post(void *ap, int rc)
3672 {
3673 struct vop_rmdir_args *a = ap;
3674
3675 if (!rc) {
3676 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
3677 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
3678 }
3679 }
3680
3681 void
3682 vop_setattr_post(void *ap, int rc)
3683 {
3684 struct vop_setattr_args *a = ap;
3685
3686 if (!rc)
3687 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
3688 }
3689
3690 void
3691 vop_symlink_post(void *ap, int rc)
3692 {
3693 struct vop_symlink_args *a = ap;
3694
3695 if (!rc)
3696 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
3697 }
3698
3699 static struct knlist fs_knlist;
3700
3701 static void
3702 vfs_event_init(void *arg)
3703 {
3704 knlist_init(&fs_knlist, NULL, NULL, NULL, NULL);
3705 }
3706 /* XXX - correct order? */
3707 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
3708
3709 void
3710 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused)
3711 {
3712
3713 KNOTE_UNLOCKED(&fs_knlist, event);
3714 }
3715
3716 static int filt_fsattach(struct knote *kn);
3717 static void filt_fsdetach(struct knote *kn);
3718 static int filt_fsevent(struct knote *kn, long hint);
3719
3720 struct filterops fs_filtops =
3721 { 0, filt_fsattach, filt_fsdetach, filt_fsevent };
3722
3723 static int
3724 filt_fsattach(struct knote *kn)
3725 {
3726
3727 kn->kn_flags |= EV_CLEAR;
3728 knlist_add(&fs_knlist, kn, 0);
3729 return (0);
3730 }
3731
3732 static void
3733 filt_fsdetach(struct knote *kn)
3734 {
3735
3736 knlist_remove(&fs_knlist, kn, 0);
3737 }
3738
3739 static int
3740 filt_fsevent(struct knote *kn, long hint)
3741 {
3742
3743 kn->kn_fflags |= hint;
3744 return (kn->kn_fflags != 0);
3745 }
3746
3747 static int
3748 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
3749 {
3750 struct vfsidctl vc;
3751 int error;
3752 struct mount *mp;
3753
3754 error = SYSCTL_IN(req, &vc, sizeof(vc));
3755 if (error)
3756 return (error);
3757 if (vc.vc_vers != VFS_CTL_VERS1)
3758 return (EINVAL);
3759 mp = vfs_getvfs(&vc.vc_fsid);
3760 if (mp == NULL)
3761 return (ENOENT);
3762 /* ensure that a specific sysctl goes to the right filesystem. */
3763 if (strcmp(vc.vc_fstypename, "*") != 0 &&
3764 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
3765 vfs_rel(mp);
3766 return (EINVAL);
3767 }
3768 VCTLTOREQ(&vc, req);
3769 error = VFS_SYSCTL(mp, vc.vc_op, req);
3770 vfs_rel(mp);
3771 return (error);
3772 }
3773
3774 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR,
3775 NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid");
3776
3777 /*
3778 * Function to initialize a va_filerev field sensibly.
3779 * XXX: Wouldn't a random number make a lot more sense ??
3780 */
3781 u_quad_t
3782 init_va_filerev(void)
3783 {
3784 struct bintime bt;
3785
3786 getbinuptime(&bt);
3787 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
3788 }
3789
3790 static int filt_vfsread(struct knote *kn, long hint);
3791 static int filt_vfswrite(struct knote *kn, long hint);
3792 static int filt_vfsvnode(struct knote *kn, long hint);
3793 static void filt_vfsdetach(struct knote *kn);
3794 static struct filterops vfsread_filtops =
3795 { 1, NULL, filt_vfsdetach, filt_vfsread };
3796 static struct filterops vfswrite_filtops =
3797 { 1, NULL, filt_vfsdetach, filt_vfswrite };
3798 static struct filterops vfsvnode_filtops =
3799 { 1, NULL, filt_vfsdetach, filt_vfsvnode };
3800
3801 static void
3802 vfs_knllock(void *arg)
3803 {
3804 struct vnode *vp = arg;
3805
3806 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
3807 }
3808
3809 static void
3810 vfs_knlunlock(void *arg)
3811 {
3812 struct vnode *vp = arg;
3813
3814 VOP_UNLOCK(vp, 0, curthread);
3815 }
3816
3817 static int
3818 vfs_knllocked(void *arg)
3819 {
3820 struct vnode *vp = arg;
3821
3822 return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE);
3823 }
3824
3825 int
3826 vfs_kqfilter(struct vop_kqfilter_args *ap)
3827 {
3828 struct vnode *vp = ap->a_vp;
3829 struct knote *kn = ap->a_kn;
3830 struct knlist *knl;
3831
3832 switch (kn->kn_filter) {
3833 case EVFILT_READ:
3834 kn->kn_fop = &vfsread_filtops;
3835 break;
3836 case EVFILT_WRITE:
3837 kn->kn_fop = &vfswrite_filtops;
3838 break;
3839 case EVFILT_VNODE:
3840 kn->kn_fop = &vfsvnode_filtops;
3841 break;
3842 default:
3843 return (EINVAL);
3844 }
3845
3846 kn->kn_hook = (caddr_t)vp;
3847
3848 if (vp->v_pollinfo == NULL)
3849 v_addpollinfo(vp);
3850 if (vp->v_pollinfo == NULL)
3851 return (ENOMEM);
3852 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
3853 knlist_add(knl, kn, 0);
3854
3855 return (0);
3856 }
3857
3858 /*
3859 * Detach knote from vnode
3860 */
3861 static void
3862 filt_vfsdetach(struct knote *kn)
3863 {
3864 struct vnode *vp = (struct vnode *)kn->kn_hook;
3865
3866 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
3867 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
3868 }
3869
3870 /*ARGSUSED*/
3871 static int
3872 filt_vfsread(struct knote *kn, long hint)
3873 {
3874 struct vnode *vp = (struct vnode *)kn->kn_hook;
3875 struct vattr va;
3876
3877 /*
3878 * filesystem is gone, so set the EOF flag and schedule
3879 * the knote for deletion.
3880 */
3881 if (hint == NOTE_REVOKE) {
3882 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3883 return (1);
3884 }
3885
3886 if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread))
3887 return (0);
3888
3889 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
3890 return (kn->kn_data != 0);
3891 }
3892
3893 /*ARGSUSED*/
3894 static int
3895 filt_vfswrite(struct knote *kn, long hint)
3896 {
3897 /*
3898 * filesystem is gone, so set the EOF flag and schedule
3899 * the knote for deletion.
3900 */
3901 if (hint == NOTE_REVOKE)
3902 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
3903
3904 kn->kn_data = 0;
3905 return (1);
3906 }
3907
3908 static int
3909 filt_vfsvnode(struct knote *kn, long hint)
3910 {
3911 if (kn->kn_sfflags & hint)
3912 kn->kn_fflags |= hint;
3913 if (hint == NOTE_REVOKE) {
3914 kn->kn_flags |= EV_EOF;
3915 return (1);
3916 }
3917 return (kn->kn_fflags != 0);
3918 }
3919
3920 int
3921 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
3922 {
3923 int error;
3924
3925 if (dp->d_reclen > ap->a_uio->uio_resid)
3926 return (ENAMETOOLONG);
3927 error = uiomove(dp, dp->d_reclen, ap->a_uio);
3928 if (error) {
3929 if (ap->a_ncookies != NULL) {
3930 if (ap->a_cookies != NULL)
3931 free(ap->a_cookies, M_TEMP);
3932 ap->a_cookies = NULL;
3933 *ap->a_ncookies = 0;
3934 }
3935 return (error);
3936 }
3937 if (ap->a_ncookies == NULL)
3938 return (0);
3939
3940 KASSERT(ap->a_cookies,
3941 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
3942
3943 *ap->a_cookies = realloc(*ap->a_cookies,
3944 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
3945 (*ap->a_cookies)[*ap->a_ncookies] = off;
3946 return (0);
3947 }
3948
3949 /*
3950 * Mark for update the access time of the file if the filesystem
3951 * supports VA_MARK_ATIME. This functionality is used by execve
3952 * and mmap, so we want to avoid the synchronous I/O implied by
3953 * directly setting va_atime for the sake of efficiency.
3954 */
3955 void
3956 vfs_mark_atime(struct vnode *vp, struct thread *td)
3957 {
3958 struct vattr atimeattr;
3959
3960 if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
3961 VATTR_NULL(&atimeattr);
3962 atimeattr.va_vaflags |= VA_MARK_ATIME;
3963 (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td);
3964 }
3965 }
Cache object: d59cc099bd498f3def7d474c08625f59
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