43
44#include "opt_ddb.h"
45#include "opt_mac.h"
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/bio.h>
50#include <sys/buf.h>
51#include <sys/conf.h>
52#include <sys/dirent.h>
53#include <sys/event.h>
54#include <sys/eventhandler.h>
55#include <sys/extattr.h>
56#include <sys/file.h>
57#include <sys/fcntl.h>
58#include <sys/jail.h>
59#include <sys/kdb.h>
60#include <sys/kernel.h>
61#include <sys/kthread.h>
62#include <sys/malloc.h>
63#include <sys/mount.h>
64#include <sys/namei.h>
65#include <sys/priv.h>
66#include <sys/reboot.h>
67#include <sys/sleepqueue.h>
68#include <sys/stat.h>
69#include <sys/sysctl.h>
70#include <sys/syslog.h>
71#include <sys/vmmeter.h>
72#include <sys/vnode.h>
73
74#include <machine/stdarg.h>
75
76#include <security/mac/mac_framework.h>
77
78#include <vm/vm.h>
79#include <vm/vm_object.h>
80#include <vm/vm_extern.h>
81#include <vm/pmap.h>
82#include <vm/vm_map.h>
83#include <vm/vm_page.h>
84#include <vm/vm_kern.h>
85#include <vm/uma.h>
86
87#ifdef DDB
88#include <ddb/ddb.h>
89#endif
90
91static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure");
92
93static void delmntque(struct vnode *vp);
94static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
95 int slpflag, int slptimeo);
96static void syncer_shutdown(void *arg, int howto);
97static int vtryrecycle(struct vnode *vp);
98static void vbusy(struct vnode *vp);
99static void vinactive(struct vnode *, struct thread *);
100static void v_incr_usecount(struct vnode *);
101static void v_decr_usecount(struct vnode *);
102static void v_decr_useonly(struct vnode *);
103static void v_upgrade_usecount(struct vnode *);
104static void vfree(struct vnode *);
105static void vnlru_free(int);
106static void vdestroy(struct vnode *);
107static void vgonel(struct vnode *);
108static void vfs_knllock(void *arg);
109static void vfs_knlunlock(void *arg);
110static int vfs_knllocked(void *arg);
111
112
113/*
114 * Enable Giant pushdown based on whether or not the vm is mpsafe in this
115 * build. Without mpsafevm the buffer cache can not run Giant free.
116 */
117int mpsafe_vfs = 1;
118TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs);
119SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0,
120 "MPSAFE VFS");
121
122/*
123 * Number of vnodes in existence. Increased whenever getnewvnode()
124 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed
125 * vnode.
126 */
127static unsigned long numvnodes;
128
129SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
130
131/*
132 * Conversion tables for conversion from vnode types to inode formats
133 * and back.
134 */
135enum vtype iftovt_tab[16] = {
136 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
137 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
138};
139int vttoif_tab[10] = {
140 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
141 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
142};
143
144/*
145 * List of vnodes that are ready for recycling.
146 */
147static TAILQ_HEAD(freelst, vnode) vnode_free_list;
148
149/*
150 * Free vnode target. Free vnodes may simply be files which have been stat'd
151 * but not read. This is somewhat common, and a small cache of such files
152 * should be kept to avoid recreation costs.
153 */
154static u_long wantfreevnodes;
155SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
156/* Number of vnodes in the free list. */
157static u_long freevnodes;
158SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
159
160/*
161 * Various variables used for debugging the new implementation of
162 * reassignbuf().
163 * XXX these are probably of (very) limited utility now.
164 */
165static int reassignbufcalls;
166SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
167
168/*
169 * Cache for the mount type id assigned to NFS. This is used for
170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
171 */
172int nfs_mount_type = -1;
173
174/* To keep more than one thread at a time from running vfs_getnewfsid */
175static struct mtx mntid_mtx;
176
177/*
178 * Lock for any access to the following:
179 * vnode_free_list
180 * numvnodes
181 * freevnodes
182 */
183static struct mtx vnode_free_list_mtx;
184
185/* Publicly exported FS */
186struct nfs_public nfs_pub;
187
188/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
189static uma_zone_t vnode_zone;
190static uma_zone_t vnodepoll_zone;
191
192/* Set to 1 to print out reclaim of active vnodes */
193int prtactive;
194
195/*
196 * The workitem queue.
197 *
198 * It is useful to delay writes of file data and filesystem metadata
199 * for tens of seconds so that quickly created and deleted files need
200 * not waste disk bandwidth being created and removed. To realize this,
201 * we append vnodes to a "workitem" queue. When running with a soft
202 * updates implementation, most pending metadata dependencies should
203 * not wait for more than a few seconds. Thus, mounted on block devices
204 * are delayed only about a half the time that file data is delayed.
205 * Similarly, directory updates are more critical, so are only delayed
206 * about a third the time that file data is delayed. Thus, there are
207 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
208 * one each second (driven off the filesystem syncer process). The
209 * syncer_delayno variable indicates the next queue that is to be processed.
210 * Items that need to be processed soon are placed in this queue:
211 *
212 * syncer_workitem_pending[syncer_delayno]
213 *
214 * A delay of fifteen seconds is done by placing the request fifteen
215 * entries later in the queue:
216 *
217 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
218 *
219 */
220static int syncer_delayno;
221static long syncer_mask;
222LIST_HEAD(synclist, bufobj);
223static struct synclist *syncer_workitem_pending;
224/*
225 * The sync_mtx protects:
226 * bo->bo_synclist
227 * sync_vnode_count
228 * syncer_delayno
229 * syncer_state
230 * syncer_workitem_pending
231 * syncer_worklist_len
232 * rushjob
233 */
234static struct mtx sync_mtx;
235
236#define SYNCER_MAXDELAY 32
237static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
238static int syncdelay = 30; /* max time to delay syncing data */
239static int filedelay = 30; /* time to delay syncing files */
240SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, "");
241static int dirdelay = 29; /* time to delay syncing directories */
242SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, "");
243static int metadelay = 28; /* time to delay syncing metadata */
244SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, "");
245static int rushjob; /* number of slots to run ASAP */
246static int stat_rush_requests; /* number of times I/O speeded up */
247SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
248
249/*
250 * When shutting down the syncer, run it at four times normal speed.
251 */
252#define SYNCER_SHUTDOWN_SPEEDUP 4
253static int sync_vnode_count;
254static int syncer_worklist_len;
255static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
256 syncer_state;
257
258/*
259 * Number of vnodes we want to exist at any one time. This is mostly used
260 * to size hash tables in vnode-related code. It is normally not used in
261 * getnewvnode(), as wantfreevnodes is normally nonzero.)
262 *
263 * XXX desiredvnodes is historical cruft and should not exist.
264 */
265int desiredvnodes;
266SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
267 &desiredvnodes, 0, "Maximum number of vnodes");
268SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
269 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
270static int vnlru_nowhere;
271SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
272 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
273
274/*
275 * Macros to control when a vnode is freed and recycled. All require
276 * the vnode interlock.
277 */
278#define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
279#define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
280#define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
281
282
283/*
284 * Initialize the vnode management data structures.
285 */
286#ifndef MAXVNODES_MAX
287#define MAXVNODES_MAX 100000
288#endif
289static void
290vntblinit(void *dummy __unused)
291{
292
293 /*
294 * Desiredvnodes is a function of the physical memory size and
295 * the kernel's heap size. Specifically, desiredvnodes scales
296 * in proportion to the physical memory size until two fifths
297 * of the kernel's heap size is consumed by vnodes and vm
298 * objects.
299 */
300 desiredvnodes = min(maxproc + VMCNT_GET(page_count) / 4, 2 *
301 vm_kmem_size / (5 * (sizeof(struct vm_object) +
302 sizeof(struct vnode))));
303 if (desiredvnodes > MAXVNODES_MAX) {
304 if (bootverbose)
305 printf("Reducing kern.maxvnodes %d -> %d\n",
306 desiredvnodes, MAXVNODES_MAX);
307 desiredvnodes = MAXVNODES_MAX;
308 }
309 wantfreevnodes = desiredvnodes / 4;
310 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
311 TAILQ_INIT(&vnode_free_list);
312 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
313 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
314 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
315 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
316 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
317 /*
318 * Initialize the filesystem syncer.
319 */
320 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
321 &syncer_mask);
322 syncer_maxdelay = syncer_mask + 1;
323 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
324}
325SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL)
326
327
328/*
329 * Mark a mount point as busy. Used to synchronize access and to delay
330 * unmounting. Interlock is not released on failure.
331 */
332int
333vfs_busy(struct mount *mp, int flags, struct mtx *interlkp,
334 struct thread *td)
335{
336 int lkflags;
337
338 MNT_ILOCK(mp);
339 MNT_REF(mp);
340 if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
341 if (flags & LK_NOWAIT) {
342 MNT_REL(mp);
343 MNT_IUNLOCK(mp);
344 return (ENOENT);
345 }
346 if (interlkp)
347 mtx_unlock(interlkp);
348 mp->mnt_kern_flag |= MNTK_MWAIT;
349 /*
350 * Since all busy locks are shared except the exclusive
351 * lock granted when unmounting, the only place that a
352 * wakeup needs to be done is at the release of the
353 * exclusive lock at the end of dounmount.
354 */
355 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0);
356 MNT_REL(mp);
357 MNT_IUNLOCK(mp);
358 if (interlkp)
359 mtx_lock(interlkp);
360 return (ENOENT);
361 }
362 if (interlkp)
363 mtx_unlock(interlkp);
364 lkflags = LK_SHARED | LK_INTERLOCK;
365 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td))
366 panic("vfs_busy: unexpected lock failure");
367 return (0);
368}
369
370/*
371 * Free a busy filesystem.
372 */
373void
374vfs_unbusy(struct mount *mp, struct thread *td)
375{
376
377 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
378 vfs_rel(mp);
379}
380
381/*
382 * Lookup a mount point by filesystem identifier.
383 */
384struct mount *
385vfs_getvfs(fsid_t *fsid)
386{
387 struct mount *mp;
388
389 mtx_lock(&mountlist_mtx);
390 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
391 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
392 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
393 vfs_ref(mp);
394 mtx_unlock(&mountlist_mtx);
395 return (mp);
396 }
397 }
398 mtx_unlock(&mountlist_mtx);
399 return ((struct mount *) 0);
400}
401
402/*
403 * Check if a user can access privileged mount options.
404 */
405int
406vfs_suser(struct mount *mp, struct thread *td)
407{
408 int error;
409
410 /*
411 * If the thread is jailed, but this is not a jail-friendly file
412 * system, deny immediately.
413 */
414 if (jailed(td->td_ucred) && !(mp->mnt_vfc->vfc_flags & VFCF_JAIL))
415 return (EPERM);
416
417 /*
418 * If the file system was mounted outside a jail and a jailed thread
419 * tries to access it, deny immediately.
420 */
421 if (!jailed(mp->mnt_cred) && jailed(td->td_ucred))
422 return (EPERM);
423
424 /*
425 * If the file system was mounted inside different jail that the jail of
426 * the calling thread, deny immediately.
427 */
428 if (jailed(mp->mnt_cred) && jailed(td->td_ucred) &&
429 mp->mnt_cred->cr_prison != td->td_ucred->cr_prison) {
430 return (EPERM);
431 }
432
433 if ((mp->mnt_flag & MNT_USER) == 0 ||
434 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
435 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
436 return (error);
437 }
438 return (0);
439}
440
441/*
442 * Get a new unique fsid. Try to make its val[0] unique, since this value
443 * will be used to create fake device numbers for stat(). Also try (but
444 * not so hard) make its val[0] unique mod 2^16, since some emulators only
445 * support 16-bit device numbers. We end up with unique val[0]'s for the
446 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
447 *
448 * Keep in mind that several mounts may be running in parallel. Starting
449 * the search one past where the previous search terminated is both a
450 * micro-optimization and a defense against returning the same fsid to
451 * different mounts.
452 */
453void
454vfs_getnewfsid(struct mount *mp)
455{
456 static u_int16_t mntid_base;
457 struct mount *nmp;
458 fsid_t tfsid;
459 int mtype;
460
461 mtx_lock(&mntid_mtx);
462 mtype = mp->mnt_vfc->vfc_typenum;
463 tfsid.val[1] = mtype;
464 mtype = (mtype & 0xFF) << 24;
465 for (;;) {
466 tfsid.val[0] = makedev(255,
467 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
468 mntid_base++;
469 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
470 break;
471 vfs_rel(nmp);
472 }
473 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
474 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
475 mtx_unlock(&mntid_mtx);
476}
477
478/*
479 * Knob to control the precision of file timestamps:
480 *
481 * 0 = seconds only; nanoseconds zeroed.
482 * 1 = seconds and nanoseconds, accurate within 1/HZ.
483 * 2 = seconds and nanoseconds, truncated to microseconds.
484 * >=3 = seconds and nanoseconds, maximum precision.
485 */
486enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
487
488static int timestamp_precision = TSP_SEC;
489SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
490 ×tamp_precision, 0, "");
491
492/*
493 * Get a current timestamp.
494 */
495void
496vfs_timestamp(struct timespec *tsp)
497{
498 struct timeval tv;
499
500 switch (timestamp_precision) {
501 case TSP_SEC:
502 tsp->tv_sec = time_second;
503 tsp->tv_nsec = 0;
504 break;
505 case TSP_HZ:
506 getnanotime(tsp);
507 break;
508 case TSP_USEC:
509 microtime(&tv);
510 TIMEVAL_TO_TIMESPEC(&tv, tsp);
511 break;
512 case TSP_NSEC:
513 default:
514 nanotime(tsp);
515 break;
516 }
517}
518
519/*
520 * Set vnode attributes to VNOVAL
521 */
522void
523vattr_null(struct vattr *vap)
524{
525
526 vap->va_type = VNON;
527 vap->va_size = VNOVAL;
528 vap->va_bytes = VNOVAL;
529 vap->va_mode = VNOVAL;
530 vap->va_nlink = VNOVAL;
531 vap->va_uid = VNOVAL;
532 vap->va_gid = VNOVAL;
533 vap->va_fsid = VNOVAL;
534 vap->va_fileid = VNOVAL;
535 vap->va_blocksize = VNOVAL;
536 vap->va_rdev = VNOVAL;
537 vap->va_atime.tv_sec = VNOVAL;
538 vap->va_atime.tv_nsec = VNOVAL;
539 vap->va_mtime.tv_sec = VNOVAL;
540 vap->va_mtime.tv_nsec = VNOVAL;
541 vap->va_ctime.tv_sec = VNOVAL;
542 vap->va_ctime.tv_nsec = VNOVAL;
543 vap->va_birthtime.tv_sec = VNOVAL;
544 vap->va_birthtime.tv_nsec = VNOVAL;
545 vap->va_flags = VNOVAL;
546 vap->va_gen = VNOVAL;
547 vap->va_vaflags = 0;
548}
549
550/*
551 * This routine is called when we have too many vnodes. It attempts
552 * to free <count> vnodes and will potentially free vnodes that still
553 * have VM backing store (VM backing store is typically the cause
554 * of a vnode blowout so we want to do this). Therefore, this operation
555 * is not considered cheap.
556 *
557 * A number of conditions may prevent a vnode from being reclaimed.
558 * the buffer cache may have references on the vnode, a directory
559 * vnode may still have references due to the namei cache representing
560 * underlying files, or the vnode may be in active use. It is not
561 * desireable to reuse such vnodes. These conditions may cause the
562 * number of vnodes to reach some minimum value regardless of what
563 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
564 */
565static int
566vlrureclaim(struct mount *mp)
567{
568 struct thread *td;
569 struct vnode *vp;
570 int done;
571 int trigger;
572 int usevnodes;
573 int count;
574
575 /*
576 * Calculate the trigger point, don't allow user
577 * screwups to blow us up. This prevents us from
578 * recycling vnodes with lots of resident pages. We
579 * aren't trying to free memory, we are trying to
580 * free vnodes.
581 */
582 usevnodes = desiredvnodes;
583 if (usevnodes <= 0)
584 usevnodes = 1;
585 trigger = VMCNT_GET(page_count) * 2 / usevnodes;
586 done = 0;
587 td = curthread;
588 vn_start_write(NULL, &mp, V_WAIT);
589 MNT_ILOCK(mp);
590 count = mp->mnt_nvnodelistsize / 10 + 1;
591 while (count != 0) {
592 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
593 while (vp != NULL && vp->v_type == VMARKER)
594 vp = TAILQ_NEXT(vp, v_nmntvnodes);
595 if (vp == NULL)
596 break;
597 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
598 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
599 --count;
600 if (!VI_TRYLOCK(vp))
601 goto next_iter;
602 /*
603 * If it's been deconstructed already, it's still
604 * referenced, or it exceeds the trigger, skip it.
605 */
606 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
607 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
608 vp->v_object->resident_page_count > trigger)) {
609 VI_UNLOCK(vp);
610 goto next_iter;
611 }
612 MNT_IUNLOCK(mp);
613 vholdl(vp);
614 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) {
615 vdrop(vp);
616 goto next_iter_mntunlocked;
617 }
618 VI_LOCK(vp);
619 /*
620 * v_usecount may have been bumped after VOP_LOCK() dropped
621 * the vnode interlock and before it was locked again.
622 *
623 * It is not necessary to recheck VI_DOOMED because it can
624 * only be set by another thread that holds both the vnode
625 * lock and vnode interlock. If another thread has the
626 * vnode lock before we get to VOP_LOCK() and obtains the
627 * vnode interlock after VOP_LOCK() drops the vnode
628 * interlock, the other thread will be unable to drop the
629 * vnode lock before our VOP_LOCK() call fails.
630 */
631 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
632 (vp->v_object != NULL &&
633 vp->v_object->resident_page_count > trigger)) {
634 VOP_UNLOCK(vp, LK_INTERLOCK, td);
635 goto next_iter_mntunlocked;
636 }
637 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
638 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
639 vgonel(vp);
640 VOP_UNLOCK(vp, 0, td);
641 vdropl(vp);
642 done++;
643next_iter_mntunlocked:
644 if ((count % 256) != 0)
645 goto relock_mnt;
646 goto yield;
647next_iter:
648 if ((count % 256) != 0)
649 continue;
650 MNT_IUNLOCK(mp);
651yield:
652 uio_yield();
653relock_mnt:
654 MNT_ILOCK(mp);
655 }
656 MNT_IUNLOCK(mp);
657 vn_finished_write(mp);
658 return done;
659}
660
661/*
662 * Attempt to keep the free list at wantfreevnodes length.
663 */
664static void
665vnlru_free(int count)
666{
667 struct vnode *vp;
668 int vfslocked;
669
670 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
671 for (; count > 0; count--) {
672 vp = TAILQ_FIRST(&vnode_free_list);
673 /*
674 * The list can be modified while the free_list_mtx
675 * has been dropped and vp could be NULL here.
676 */
677 if (!vp)
678 break;
679 VNASSERT(vp->v_op != NULL, vp,
680 ("vnlru_free: vnode already reclaimed."));
681 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
682 /*
683 * Don't recycle if we can't get the interlock.
684 */
685 if (!VI_TRYLOCK(vp)) {
686 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
687 continue;
688 }
689 VNASSERT(VCANRECYCLE(vp), vp,
690 ("vp inconsistent on freelist"));
691 freevnodes--;
692 vp->v_iflag &= ~VI_FREE;
693 vholdl(vp);
694 mtx_unlock(&vnode_free_list_mtx);
695 VI_UNLOCK(vp);
696 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
697 vtryrecycle(vp);
698 VFS_UNLOCK_GIANT(vfslocked);
699 /*
700 * If the recycled succeeded this vdrop will actually free
701 * the vnode. If not it will simply place it back on
702 * the free list.
703 */
704 vdrop(vp);
705 mtx_lock(&vnode_free_list_mtx);
706 }
707}
708/*
709 * Attempt to recycle vnodes in a context that is always safe to block.
710 * Calling vlrurecycle() from the bowels of filesystem code has some
711 * interesting deadlock problems.
712 */
713static struct proc *vnlruproc;
714static int vnlruproc_sig;
715
716static void
717vnlru_proc(void)
718{
719 struct mount *mp, *nmp;
720 int done;
721 struct proc *p = vnlruproc;
722 struct thread *td = FIRST_THREAD_IN_PROC(p);
723
724 mtx_lock(&Giant);
725
726 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
727 SHUTDOWN_PRI_FIRST);
728
729 for (;;) {
730 kthread_suspend_check(p);
731 mtx_lock(&vnode_free_list_mtx);
732 if (freevnodes > wantfreevnodes)
733 vnlru_free(freevnodes - wantfreevnodes);
734 if (numvnodes <= desiredvnodes * 9 / 10) {
735 vnlruproc_sig = 0;
736 wakeup(&vnlruproc_sig);
737 msleep(vnlruproc, &vnode_free_list_mtx,
738 PVFS|PDROP, "vlruwt", hz);
739 continue;
740 }
741 mtx_unlock(&vnode_free_list_mtx);
742 done = 0;
743 mtx_lock(&mountlist_mtx);
744 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
745 int vfsunlocked;
746 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
747 nmp = TAILQ_NEXT(mp, mnt_list);
748 continue;
749 }
750 if (!VFS_NEEDSGIANT(mp)) {
751 mtx_unlock(&Giant);
752 vfsunlocked = 1;
753 } else
754 vfsunlocked = 0;
755 done += vlrureclaim(mp);
756 if (vfsunlocked)
757 mtx_lock(&Giant);
758 mtx_lock(&mountlist_mtx);
759 nmp = TAILQ_NEXT(mp, mnt_list);
760 vfs_unbusy(mp, td);
761 }
762 mtx_unlock(&mountlist_mtx);
763 if (done == 0) {
764 EVENTHANDLER_INVOKE(vfs_lowvnodes, desiredvnodes / 10);
765#if 0
766 /* These messages are temporary debugging aids */
767 if (vnlru_nowhere < 5)
768 printf("vnlru process getting nowhere..\n");
769 else if (vnlru_nowhere == 5)
770 printf("vnlru process messages stopped.\n");
771#endif
772 vnlru_nowhere++;
773 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
774 } else
775 uio_yield();
776 }
777}
778
779static struct kproc_desc vnlru_kp = {
780 "vnlru",
781 vnlru_proc,
782 &vnlruproc
783};
784SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp)
785
786/*
787 * Routines having to do with the management of the vnode table.
788 */
789
790static void
791vdestroy(struct vnode *vp)
792{
793 struct bufobj *bo;
794
795 CTR1(KTR_VFS, "vdestroy vp %p", vp);
796 mtx_lock(&vnode_free_list_mtx);
797 numvnodes--;
798 mtx_unlock(&vnode_free_list_mtx);
799 bo = &vp->v_bufobj;
800 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
801 ("cleaned vnode still on the free list."));
802 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
803 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
804 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
805 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
806 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
807 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
808 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
809 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
810 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
811 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
812 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
813 VI_UNLOCK(vp);
814#ifdef MAC
815 mac_destroy_vnode(vp);
816#endif
817 if (vp->v_pollinfo != NULL) {
818 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note);
819 mtx_destroy(&vp->v_pollinfo->vpi_lock);
820 uma_zfree(vnodepoll_zone, vp->v_pollinfo);
821 }
822#ifdef INVARIANTS
823 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */
824 vp->v_op = NULL;
825#endif
826 lockdestroy(vp->v_vnlock);
827 mtx_destroy(&vp->v_interlock);
828 uma_zfree(vnode_zone, vp);
829}
830
831/*
832 * Try to recycle a freed vnode. We abort if anyone picks up a reference
833 * before we actually vgone(). This function must be called with the vnode
834 * held to prevent the vnode from being returned to the free list midway
835 * through vgone().
836 */
837static int
838vtryrecycle(struct vnode *vp)
839{
840 struct thread *td = curthread;
841 struct mount *vnmp;
842
843 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp);
844 VNASSERT(vp->v_holdcnt, vp,
845 ("vtryrecycle: Recycling vp %p without a reference.", vp));
846 /*
847 * This vnode may found and locked via some other list, if so we
848 * can't recycle it yet.
849 */
850 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0)
851 return (EWOULDBLOCK);
852 /*
853 * Don't recycle if its filesystem is being suspended.
854 */
855 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
856 VOP_UNLOCK(vp, 0, td);
857 return (EBUSY);
858 }
859 /*
860 * If we got this far, we need to acquire the interlock and see if
861 * anyone picked up this vnode from another list. If not, we will
862 * mark it with DOOMED via vgonel() so that anyone who does find it
863 * will skip over it.
864 */
865 VI_LOCK(vp);
866 if (vp->v_usecount) {
867 VOP_UNLOCK(vp, LK_INTERLOCK, td);
868 vn_finished_write(vnmp);
869 return (EBUSY);
870 }
871 if ((vp->v_iflag & VI_DOOMED) == 0)
872 vgonel(vp);
873 VOP_UNLOCK(vp, LK_INTERLOCK, td);
874 vn_finished_write(vnmp);
875 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp);
876 return (0);
877}
878
879/*
880 * Return the next vnode from the free list.
881 */
882int
883getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
884 struct vnode **vpp)
885{
886 struct vnode *vp = NULL;
887 struct bufobj *bo;
888
889 mtx_lock(&vnode_free_list_mtx);
890 /*
891 * Lend our context to reclaim vnodes if they've exceeded the max.
892 */
893 if (freevnodes > wantfreevnodes)
894 vnlru_free(1);
895 /*
896 * Wait for available vnodes.
897 */
898 if (numvnodes > desiredvnodes) {
899 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
900 /*
901 * File system is beeing suspended, we cannot risk a
902 * deadlock here, so allocate new vnode anyway.
903 */
904 if (freevnodes > wantfreevnodes)
905 vnlru_free(freevnodes - wantfreevnodes);
906 goto alloc;
907 }
908 if (vnlruproc_sig == 0) {
909 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
910 wakeup(vnlruproc);
911 }
912 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
913 "vlruwk", hz);
914#if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
915 if (numvnodes > desiredvnodes) {
916 mtx_unlock(&vnode_free_list_mtx);
917 return (ENFILE);
918 }
919#endif
920 }
921alloc:
922 numvnodes++;
923 mtx_unlock(&vnode_free_list_mtx);
924 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
925 /*
926 * Setup locks.
927 */
928 vp->v_vnlock = &vp->v_lock;
929 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
930 /*
931 * By default, don't allow shared locks unless filesystems
932 * opt-in.
933 */
934 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
935 /*
936 * Initialize bufobj.
937 */
938 bo = &vp->v_bufobj;
939 bo->__bo_vnode = vp;
940 bo->bo_mtx = &vp->v_interlock;
941 bo->bo_ops = &buf_ops_bio;
942 bo->bo_private = vp;
943 TAILQ_INIT(&bo->bo_clean.bv_hd);
944 TAILQ_INIT(&bo->bo_dirty.bv_hd);
945 /*
946 * Initialize namecache.
947 */
948 LIST_INIT(&vp->v_cache_src);
949 TAILQ_INIT(&vp->v_cache_dst);
950 /*
951 * Finalize various vnode identity bits.
952 */
953 vp->v_type = VNON;
954 vp->v_tag = tag;
955 vp->v_op = vops;
956 v_incr_usecount(vp);
957 vp->v_data = 0;
958#ifdef MAC
959 mac_init_vnode(vp);
960 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
961 mac_associate_vnode_singlelabel(mp, vp);
962 else if (mp == NULL)
963 printf("NULL mp in getnewvnode()\n");
964#endif
965 if (mp != NULL) {
966 bo->bo_bsize = mp->mnt_stat.f_iosize;
967 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
968 vp->v_vflag |= VV_NOKNOTE;
969 }
970
971 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp);
972 *vpp = vp;
973 return (0);
974}
975
976/*
977 * Delete from old mount point vnode list, if on one.
978 */
979static void
980delmntque(struct vnode *vp)
981{
982 struct mount *mp;
983
984 mp = vp->v_mount;
985 if (mp == NULL)
986 return;
987 MNT_ILOCK(mp);
988 vp->v_mount = NULL;
989 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
990 ("bad mount point vnode list size"));
991 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
992 mp->mnt_nvnodelistsize--;
993 MNT_REL(mp);
994 MNT_IUNLOCK(mp);
995}
996
997static void
998insmntque_stddtr(struct vnode *vp, void *dtr_arg)
999{
1000 struct thread *td;
1001
1002 td = curthread; /* XXX ? */
1003 vp->v_data = NULL;
1004 vp->v_op = &dead_vnodeops;
1005 /* XXX non mp-safe fs may still call insmntque with vnode
1006 unlocked */
1007 if (!VOP_ISLOCKED(vp, td))
1008 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1009 vgone(vp);
1010 vput(vp);
1011}
1012
1013/*
1014 * Insert into list of vnodes for the new mount point, if available.
1015 */
1016int
1017insmntque1(struct vnode *vp, struct mount *mp,
1018 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1019{
1020
1021 KASSERT(vp->v_mount == NULL,
1022 ("insmntque: vnode already on per mount vnode list"));
1023 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1024 MNT_ILOCK(mp);
1025 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
1026 mp->mnt_nvnodelistsize == 0) {
1027 MNT_IUNLOCK(mp);
1028 if (dtr != NULL)
1029 dtr(vp, dtr_arg);
1030 return (EBUSY);
1031 }
1032 vp->v_mount = mp;
1033 MNT_REF(mp);
1034 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1035 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1036 ("neg mount point vnode list size"));
1037 mp->mnt_nvnodelistsize++;
1038 MNT_IUNLOCK(mp);
1039 return (0);
1040}
1041
1042int
1043insmntque(struct vnode *vp, struct mount *mp)
1044{
1045
1046 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1047}
1048
1049/*
1050 * Flush out and invalidate all buffers associated with a bufobj
1051 * Called with the underlying object locked.
1052 */
1053int
1054bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag,
1055 int slptimeo)
1056{
1057 int error;
1058
1059 BO_LOCK(bo);
1060 if (flags & V_SAVE) {
1061 error = bufobj_wwait(bo, slpflag, slptimeo);
1062 if (error) {
1063 BO_UNLOCK(bo);
1064 return (error);
1065 }
1066 if (bo->bo_dirty.bv_cnt > 0) {
1067 BO_UNLOCK(bo);
1068 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0)
1069 return (error);
1070 /*
1071 * XXX We could save a lock/unlock if this was only
1072 * enabled under INVARIANTS
1073 */
1074 BO_LOCK(bo);
1075 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1076 panic("vinvalbuf: dirty bufs");
1077 }
1078 }
1079 /*
1080 * If you alter this loop please notice that interlock is dropped and
1081 * reacquired in flushbuflist. Special care is needed to ensure that
1082 * no race conditions occur from this.
1083 */
1084 do {
1085 error = flushbuflist(&bo->bo_clean,
1086 flags, bo, slpflag, slptimeo);
1087 if (error == 0)
1088 error = flushbuflist(&bo->bo_dirty,
1089 flags, bo, slpflag, slptimeo);
1090 if (error != 0 && error != EAGAIN) {
1091 BO_UNLOCK(bo);
1092 return (error);
1093 }
1094 } while (error != 0);
1095
1096 /*
1097 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1098 * have write I/O in-progress but if there is a VM object then the
1099 * VM object can also have read-I/O in-progress.
1100 */
1101 do {
1102 bufobj_wwait(bo, 0, 0);
1103 BO_UNLOCK(bo);
1104 if (bo->bo_object != NULL) {
1105 VM_OBJECT_LOCK(bo->bo_object);
1106 vm_object_pip_wait(bo->bo_object, "bovlbx");
1107 VM_OBJECT_UNLOCK(bo->bo_object);
1108 }
1109 BO_LOCK(bo);
1110 } while (bo->bo_numoutput > 0);
1111 BO_UNLOCK(bo);
1112
1113 /*
1114 * Destroy the copy in the VM cache, too.
1115 */
1116 if (bo->bo_object != NULL) {
1117 VM_OBJECT_LOCK(bo->bo_object);
1118 vm_object_page_remove(bo->bo_object, 0, 0,
1119 (flags & V_SAVE) ? TRUE : FALSE);
1120 VM_OBJECT_UNLOCK(bo->bo_object);
1121 }
1122
1123#ifdef INVARIANTS
1124 BO_LOCK(bo);
1125 if ((flags & (V_ALT | V_NORMAL)) == 0 &&
1126 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1127 panic("vinvalbuf: flush failed");
1128 BO_UNLOCK(bo);
1129#endif
1130 return (0);
1131}
1132
1133/*
1134 * Flush out and invalidate all buffers associated with a vnode.
1135 * Called with the underlying object locked.
1136 */
1137int
1138vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag,
1139 int slptimeo)
1140{
1141
1142 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags);
1143 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1144 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo));
1145}
1146
1147/*
1148 * Flush out buffers on the specified list.
1149 *
1150 */
1151static int
1152flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1153 int slptimeo)
1154{
1155 struct buf *bp, *nbp;
1156 int retval, error;
1157 daddr_t lblkno;
1158 b_xflags_t xflags;
1159
1160 ASSERT_BO_LOCKED(bo);
1161
1162 retval = 0;
1163 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1164 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1165 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1166 continue;
1167 }
1168 lblkno = 0;
1169 xflags = 0;
1170 if (nbp != NULL) {
1171 lblkno = nbp->b_lblkno;
1172 xflags = nbp->b_xflags &
1173 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1174 }
1175 retval = EAGAIN;
1176 error = BUF_TIMELOCK(bp,
1177 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1178 "flushbuf", slpflag, slptimeo);
1179 if (error) {
1180 BO_LOCK(bo);
1181 return (error != ENOLCK ? error : EAGAIN);
1182 }
1183 KASSERT(bp->b_bufobj == bo,
1184 ("bp %p wrong b_bufobj %p should be %p",
1185 bp, bp->b_bufobj, bo));
1186 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1187 BUF_UNLOCK(bp);
1188 BO_LOCK(bo);
1189 return (EAGAIN);
1190 }
1191 /*
1192 * XXX Since there are no node locks for NFS, I
1193 * believe there is a slight chance that a delayed
1194 * write will occur while sleeping just above, so
1195 * check for it.
1196 */
1197 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1198 (flags & V_SAVE)) {
1199 bremfree(bp);
1200 bp->b_flags |= B_ASYNC;
1201 bwrite(bp);
1202 BO_LOCK(bo);
1203 return (EAGAIN); /* XXX: why not loop ? */
1204 }
1205 bremfree(bp);
1206 bp->b_flags |= (B_INVAL | B_RELBUF);
1207 bp->b_flags &= ~B_ASYNC;
1208 brelse(bp);
1209 BO_LOCK(bo);
1210 if (nbp != NULL &&
1211 (nbp->b_bufobj != bo ||
1212 nbp->b_lblkno != lblkno ||
1213 (nbp->b_xflags &
1214 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1215 break; /* nbp invalid */
1216 }
1217 return (retval);
1218}
1219
1220/*
1221 * Truncate a file's buffer and pages to a specified length. This
1222 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1223 * sync activity.
1224 */
1225int
1226vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
1227 off_t length, int blksize)
1228{
1229 struct buf *bp, *nbp;
1230 int anyfreed;
1231 int trunclbn;
1232 struct bufobj *bo;
1233
1234 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length);
1235 /*
1236 * Round up to the *next* lbn.
1237 */
1238 trunclbn = (length + blksize - 1) / blksize;
1239
1240 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1241restart:
1242 VI_LOCK(vp);
1243 bo = &vp->v_bufobj;
1244 anyfreed = 1;
1245 for (;anyfreed;) {
1246 anyfreed = 0;
1247 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1248 if (bp->b_lblkno < trunclbn)
1249 continue;
1250 if (BUF_LOCK(bp,
1251 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1252 VI_MTX(vp)) == ENOLCK)
1253 goto restart;
1254
1255 bremfree(bp);
1256 bp->b_flags |= (B_INVAL | B_RELBUF);
1257 bp->b_flags &= ~B_ASYNC;
1258 brelse(bp);
1259 anyfreed = 1;
1260
1261 if (nbp != NULL &&
1262 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1263 (nbp->b_vp != vp) ||
1264 (nbp->b_flags & B_DELWRI))) {
1265 goto restart;
1266 }
1267 VI_LOCK(vp);
1268 }
1269
1270 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1271 if (bp->b_lblkno < trunclbn)
1272 continue;
1273 if (BUF_LOCK(bp,
1274 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1275 VI_MTX(vp)) == ENOLCK)
1276 goto restart;
1277 bremfree(bp);
1278 bp->b_flags |= (B_INVAL | B_RELBUF);
1279 bp->b_flags &= ~B_ASYNC;
1280 brelse(bp);
1281 anyfreed = 1;
1282 if (nbp != NULL &&
1283 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1284 (nbp->b_vp != vp) ||
1285 (nbp->b_flags & B_DELWRI) == 0)) {
1286 goto restart;
1287 }
1288 VI_LOCK(vp);
1289 }
1290 }
1291
1292 if (length > 0) {
1293restartsync:
1294 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1295 if (bp->b_lblkno > 0)
1296 continue;
1297 /*
1298 * Since we hold the vnode lock this should only
1299 * fail if we're racing with the buf daemon.
1300 */
1301 if (BUF_LOCK(bp,
1302 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1303 VI_MTX(vp)) == ENOLCK) {
1304 goto restart;
1305 }
1306 VNASSERT((bp->b_flags & B_DELWRI), vp,
1307 ("buf(%p) on dirty queue without DELWRI", bp));
1308
1309 bremfree(bp);
1310 bawrite(bp);
1311 VI_LOCK(vp);
1312 goto restartsync;
1313 }
1314 }
1315
1316 bufobj_wwait(bo, 0, 0);
1317 VI_UNLOCK(vp);
1318 vnode_pager_setsize(vp, length);
1319
1320 return (0);
1321}
1322
1323/*
1324 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1325 * a vnode.
1326 *
1327 * NOTE: We have to deal with the special case of a background bitmap
1328 * buffer, a situation where two buffers will have the same logical
1329 * block offset. We want (1) only the foreground buffer to be accessed
1330 * in a lookup and (2) must differentiate between the foreground and
1331 * background buffer in the splay tree algorithm because the splay
1332 * tree cannot normally handle multiple entities with the same 'index'.
1333 * We accomplish this by adding differentiating flags to the splay tree's
1334 * numerical domain.
1335 */
1336static
1337struct buf *
1338buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1339{
1340 struct buf dummy;
1341 struct buf *lefttreemax, *righttreemin, *y;
1342
1343 if (root == NULL)
1344 return (NULL);
1345 lefttreemax = righttreemin = &dummy;
1346 for (;;) {
1347 if (lblkno < root->b_lblkno ||
1348 (lblkno == root->b_lblkno &&
1349 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1350 if ((y = root->b_left) == NULL)
1351 break;
1352 if (lblkno < y->b_lblkno) {
1353 /* Rotate right. */
1354 root->b_left = y->b_right;
1355 y->b_right = root;
1356 root = y;
1357 if ((y = root->b_left) == NULL)
1358 break;
1359 }
1360 /* Link into the new root's right tree. */
1361 righttreemin->b_left = root;
1362 righttreemin = root;
1363 } else if (lblkno > root->b_lblkno ||
1364 (lblkno == root->b_lblkno &&
1365 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1366 if ((y = root->b_right) == NULL)
1367 break;
1368 if (lblkno > y->b_lblkno) {
1369 /* Rotate left. */
1370 root->b_right = y->b_left;
1371 y->b_left = root;
1372 root = y;
1373 if ((y = root->b_right) == NULL)
1374 break;
1375 }
1376 /* Link into the new root's left tree. */
1377 lefttreemax->b_right = root;
1378 lefttreemax = root;
1379 } else {
1380 break;
1381 }
1382 root = y;
1383 }
1384 /* Assemble the new root. */
1385 lefttreemax->b_right = root->b_left;
1386 righttreemin->b_left = root->b_right;
1387 root->b_left = dummy.b_right;
1388 root->b_right = dummy.b_left;
1389 return (root);
1390}
1391
1392static void
1393buf_vlist_remove(struct buf *bp)
1394{
1395 struct buf *root;
1396 struct bufv *bv;
1397
1398 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1399 ASSERT_BO_LOCKED(bp->b_bufobj);
1400 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1401 (BX_VNDIRTY|BX_VNCLEAN),
1402 ("buf_vlist_remove: Buf %p is on two lists", bp));
1403 if (bp->b_xflags & BX_VNDIRTY)
1404 bv = &bp->b_bufobj->bo_dirty;
1405 else
1406 bv = &bp->b_bufobj->bo_clean;
1407 if (bp != bv->bv_root) {
1408 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1409 KASSERT(root == bp, ("splay lookup failed in remove"));
1410 }
1411 if (bp->b_left == NULL) {
1412 root = bp->b_right;
1413 } else {
1414 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1415 root->b_right = bp->b_right;
1416 }
1417 bv->bv_root = root;
1418 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1419 bv->bv_cnt--;
1420 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1421}
1422
1423/*
1424 * Add the buffer to the sorted clean or dirty block list using a
1425 * splay tree algorithm.
1426 *
1427 * NOTE: xflags is passed as a constant, optimizing this inline function!
1428 */
1429static void
1430buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1431{
1432 struct buf *root;
1433 struct bufv *bv;
1434
1435 ASSERT_BO_LOCKED(bo);
1436 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1437 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1438 bp->b_xflags |= xflags;
1439 if (xflags & BX_VNDIRTY)
1440 bv = &bo->bo_dirty;
1441 else
1442 bv = &bo->bo_clean;
1443
1444 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1445 if (root == NULL) {
1446 bp->b_left = NULL;
1447 bp->b_right = NULL;
1448 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1449 } else if (bp->b_lblkno < root->b_lblkno ||
1450 (bp->b_lblkno == root->b_lblkno &&
1451 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1452 bp->b_left = root->b_left;
1453 bp->b_right = root;
1454 root->b_left = NULL;
1455 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1456 } else {
1457 bp->b_right = root->b_right;
1458 bp->b_left = root;
1459 root->b_right = NULL;
1460 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1461 }
1462 bv->bv_cnt++;
1463 bv->bv_root = bp;
1464}
1465
1466/*
1467 * Lookup a buffer using the splay tree. Note that we specifically avoid
1468 * shadow buffers used in background bitmap writes.
1469 *
1470 * This code isn't quite efficient as it could be because we are maintaining
1471 * two sorted lists and do not know which list the block resides in.
1472 *
1473 * During a "make buildworld" the desired buffer is found at one of
1474 * the roots more than 60% of the time. Thus, checking both roots
1475 * before performing either splay eliminates unnecessary splays on the
1476 * first tree splayed.
1477 */
1478struct buf *
1479gbincore(struct bufobj *bo, daddr_t lblkno)
1480{
1481 struct buf *bp;
1482
1483 ASSERT_BO_LOCKED(bo);
1484 if ((bp = bo->bo_clean.bv_root) != NULL &&
1485 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1486 return (bp);
1487 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1488 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1489 return (bp);
1490 if ((bp = bo->bo_clean.bv_root) != NULL) {
1491 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1492 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1493 return (bp);
1494 }
1495 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1496 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1497 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1498 return (bp);
1499 }
1500 return (NULL);
1501}
1502
1503/*
1504 * Associate a buffer with a vnode.
1505 */
1506void
1507bgetvp(struct vnode *vp, struct buf *bp)
1508{
1509
1510 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1511
1512 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1513 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1514 ("bgetvp: bp already attached! %p", bp));
1515
1516 ASSERT_VI_LOCKED(vp, "bgetvp");
1517 vholdl(vp);
1518 if (VFS_NEEDSGIANT(vp->v_mount) ||
1519 vp->v_bufobj.bo_flag & BO_NEEDSGIANT)
1520 bp->b_flags |= B_NEEDSGIANT;
1521 bp->b_vp = vp;
1522 bp->b_bufobj = &vp->v_bufobj;
1523 /*
1524 * Insert onto list for new vnode.
1525 */
1526 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN);
1527}
1528
1529/*
1530 * Disassociate a buffer from a vnode.
1531 */
1532void
1533brelvp(struct buf *bp)
1534{
1535 struct bufobj *bo;
1536 struct vnode *vp;
1537
1538 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1539 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1540
1541 /*
1542 * Delete from old vnode list, if on one.
1543 */
1544 vp = bp->b_vp; /* XXX */
1545 bo = bp->b_bufobj;
1546 BO_LOCK(bo);
1547 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1548 buf_vlist_remove(bp);
1549 else
1550 panic("brelvp: Buffer %p not on queue.", bp);
1551 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1552 bo->bo_flag &= ~BO_ONWORKLST;
1553 mtx_lock(&sync_mtx);
1554 LIST_REMOVE(bo, bo_synclist);
1555 syncer_worklist_len--;
1556 mtx_unlock(&sync_mtx);
1557 }
1558 bp->b_flags &= ~B_NEEDSGIANT;
1559 bp->b_vp = NULL;
1560 bp->b_bufobj = NULL;
1561 vdropl(vp);
1562}
1563
1564/*
1565 * Add an item to the syncer work queue.
1566 */
1567static void
1568vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1569{
1570 int slot;
1571
1572 ASSERT_BO_LOCKED(bo);
1573
1574 mtx_lock(&sync_mtx);
1575 if (bo->bo_flag & BO_ONWORKLST)
1576 LIST_REMOVE(bo, bo_synclist);
1577 else {
1578 bo->bo_flag |= BO_ONWORKLST;
1579 syncer_worklist_len++;
1580 }
1581
1582 if (delay > syncer_maxdelay - 2)
1583 delay = syncer_maxdelay - 2;
1584 slot = (syncer_delayno + delay) & syncer_mask;
1585
1586 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
1587 mtx_unlock(&sync_mtx);
1588}
1589
1590static int
1591sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1592{
1593 int error, len;
1594
1595 mtx_lock(&sync_mtx);
1596 len = syncer_worklist_len - sync_vnode_count;
1597 mtx_unlock(&sync_mtx);
1598 error = SYSCTL_OUT(req, &len, sizeof(len));
1599 return (error);
1600}
1601
1602SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1603 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1604
1605static struct proc *updateproc;
1606static void sched_sync(void);
1607static struct kproc_desc up_kp = {
1608 "syncer",
1609 sched_sync,
1610 &updateproc
1611};
1612SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
1613
1614static int
1615sync_vnode(struct bufobj *bo, struct thread *td)
1616{
1617 struct vnode *vp;
1618 struct mount *mp;
1619
1620 vp = bo->__bo_vnode; /* XXX */
1621 if (VOP_ISLOCKED(vp, NULL) != 0)
1622 return (1);
1623 if (VI_TRYLOCK(vp) == 0)
1624 return (1);
1625 /*
1626 * We use vhold in case the vnode does not
1627 * successfully sync. vhold prevents the vnode from
1628 * going away when we unlock the sync_mtx so that
1629 * we can acquire the vnode interlock.
1630 */
1631 vholdl(vp);
1632 mtx_unlock(&sync_mtx);
1633 VI_UNLOCK(vp);
1634 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1635 vdrop(vp);
1636 mtx_lock(&sync_mtx);
1637 return (1);
1638 }
1639 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1640 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1641 VOP_UNLOCK(vp, 0, td);
1642 vn_finished_write(mp);
1643 VI_LOCK(vp);
1644 if ((bo->bo_flag & BO_ONWORKLST) != 0) {
1645 /*
1646 * Put us back on the worklist. The worklist
1647 * routine will remove us from our current
1648 * position and then add us back in at a later
1649 * position.
1650 */
1651 vn_syncer_add_to_worklist(bo, syncdelay);
1652 }
1653 vdropl(vp);
1654 mtx_lock(&sync_mtx);
1655 return (0);
1656}
1657
1658/*
1659 * System filesystem synchronizer daemon.
1660 */
1661static void
1662sched_sync(void)
1663{
1664 struct synclist *next;
1665 struct synclist *slp;
1666 struct bufobj *bo;
1667 long starttime;
1668 struct thread *td = FIRST_THREAD_IN_PROC(updateproc);
1669 static int dummychan;
1670 int last_work_seen;
1671 int net_worklist_len;
1672 int syncer_final_iter;
1673 int first_printf;
1674 int error;
1675
1676 mtx_lock(&Giant);
1677 last_work_seen = 0;
1678 syncer_final_iter = 0;
1679 first_printf = 1;
1680 syncer_state = SYNCER_RUNNING;
1681 starttime = time_uptime;
1682 td->td_pflags |= TDP_NORUNNINGBUF;
1683
1684 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1685 SHUTDOWN_PRI_LAST);
1686
1687 mtx_lock(&sync_mtx);
1688 for (;;) {
1689 if (syncer_state == SYNCER_FINAL_DELAY &&
1690 syncer_final_iter == 0) {
1691 mtx_unlock(&sync_mtx);
1692 kthread_suspend_check(td->td_proc);
1693 mtx_lock(&sync_mtx);
1694 }
1695 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1696 if (syncer_state != SYNCER_RUNNING &&
1697 starttime != time_uptime) {
1698 if (first_printf) {
1699 printf("\nSyncing disks, vnodes remaining...");
1700 first_printf = 0;
1701 }
1702 printf("%d ", net_worklist_len);
1703 }
1704 starttime = time_uptime;
1705
1706 /*
1707 * Push files whose dirty time has expired. Be careful
1708 * of interrupt race on slp queue.
1709 *
1710 * Skip over empty worklist slots when shutting down.
1711 */
1712 do {
1713 slp = &syncer_workitem_pending[syncer_delayno];
1714 syncer_delayno += 1;
1715 if (syncer_delayno == syncer_maxdelay)
1716 syncer_delayno = 0;
1717 next = &syncer_workitem_pending[syncer_delayno];
1718 /*
1719 * If the worklist has wrapped since the
1720 * it was emptied of all but syncer vnodes,
1721 * switch to the FINAL_DELAY state and run
1722 * for one more second.
1723 */
1724 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1725 net_worklist_len == 0 &&
1726 last_work_seen == syncer_delayno) {
1727 syncer_state = SYNCER_FINAL_DELAY;
1728 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1729 }
1730 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1731 syncer_worklist_len > 0);
1732
1733 /*
1734 * Keep track of the last time there was anything
1735 * on the worklist other than syncer vnodes.
1736 * Return to the SHUTTING_DOWN state if any
1737 * new work appears.
1738 */
1739 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1740 last_work_seen = syncer_delayno;
1741 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1742 syncer_state = SYNCER_SHUTTING_DOWN;
1743 while ((bo = LIST_FIRST(slp)) != NULL) {
1744 error = sync_vnode(bo, td);
1745 if (error == 1) {
1746 LIST_REMOVE(bo, bo_synclist);
1747 LIST_INSERT_HEAD(next, bo, bo_synclist);
1748 continue;
1749 }
1750 }
1751 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1752 syncer_final_iter--;
1753 /*
1754 * The variable rushjob allows the kernel to speed up the
1755 * processing of the filesystem syncer process. A rushjob
1756 * value of N tells the filesystem syncer to process the next
1757 * N seconds worth of work on its queue ASAP. Currently rushjob
1758 * is used by the soft update code to speed up the filesystem
1759 * syncer process when the incore state is getting so far
1760 * ahead of the disk that the kernel memory pool is being
1761 * threatened with exhaustion.
1762 */
1763 if (rushjob > 0) {
1764 rushjob -= 1;
1765 continue;
1766 }
1767 /*
1768 * Just sleep for a short period of time between
1769 * iterations when shutting down to allow some I/O
1770 * to happen.
1771 *
1772 * If it has taken us less than a second to process the
1773 * current work, then wait. Otherwise start right over
1774 * again. We can still lose time if any single round
1775 * takes more than two seconds, but it does not really
1776 * matter as we are just trying to generally pace the
1777 * filesystem activity.
1778 */
1779 if (syncer_state != SYNCER_RUNNING)
1780 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl",
1781 hz / SYNCER_SHUTDOWN_SPEEDUP);
1782 else if (time_uptime == starttime)
1783 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0);
1784 }
1785}
1786
1787/*
1788 * Request the syncer daemon to speed up its work.
1789 * We never push it to speed up more than half of its
1790 * normal turn time, otherwise it could take over the cpu.
1791 */
1792int
1793speedup_syncer(void)
1794{
1795 struct thread *td;
1796 int ret = 0;
1797
1798 td = FIRST_THREAD_IN_PROC(updateproc);
1799 sleepq_remove(td, &lbolt);
1800 mtx_lock(&sync_mtx);
1801 if (rushjob < syncdelay / 2) {
1802 rushjob += 1;
1803 stat_rush_requests += 1;
1804 ret = 1;
1805 }
1806 mtx_unlock(&sync_mtx);
1807 return (ret);
1808}
1809
1810/*
1811 * Tell the syncer to speed up its work and run though its work
1812 * list several times, then tell it to shut down.
1813 */
1814static void
1815syncer_shutdown(void *arg, int howto)
1816{
1817 struct thread *td;
1818
1819 if (howto & RB_NOSYNC)
1820 return;
1821 td = FIRST_THREAD_IN_PROC(updateproc);
1822 sleepq_remove(td, &lbolt);
1823 mtx_lock(&sync_mtx);
1824 syncer_state = SYNCER_SHUTTING_DOWN;
1825 rushjob = 0;
1826 mtx_unlock(&sync_mtx);
1827 kproc_shutdown(arg, howto);
1828}
1829
1830/*
1831 * Reassign a buffer from one vnode to another.
1832 * Used to assign file specific control information
1833 * (indirect blocks) to the vnode to which they belong.
1834 */
1835void
1836reassignbuf(struct buf *bp)
1837{
1838 struct vnode *vp;
1839 struct bufobj *bo;
1840 int delay;
1841#ifdef INVARIANTS
1842 struct bufv *bv;
1843#endif
1844
1845 vp = bp->b_vp;
1846 bo = bp->b_bufobj;
1847 ++reassignbufcalls;
1848
1849 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1850 bp, bp->b_vp, bp->b_flags);
1851 /*
1852 * B_PAGING flagged buffers cannot be reassigned because their vp
1853 * is not fully linked in.
1854 */
1855 if (bp->b_flags & B_PAGING)
1856 panic("cannot reassign paging buffer");
1857
1858 /*
1859 * Delete from old vnode list, if on one.
1860 */
1861 VI_LOCK(vp);
1862 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1863 buf_vlist_remove(bp);
1864 else
1865 panic("reassignbuf: Buffer %p not on queue.", bp);
1866 /*
1867 * If dirty, put on list of dirty buffers; otherwise insert onto list
1868 * of clean buffers.
1869 */
1870 if (bp->b_flags & B_DELWRI) {
1871 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
1872 switch (vp->v_type) {
1873 case VDIR:
1874 delay = dirdelay;
1875 break;
1876 case VCHR:
1877 delay = metadelay;
1878 break;
1879 default:
1880 delay = filedelay;
1881 }
1882 vn_syncer_add_to_worklist(bo, delay);
1883 }
1884 buf_vlist_add(bp, bo, BX_VNDIRTY);
1885 } else {
1886 buf_vlist_add(bp, bo, BX_VNCLEAN);
1887
1888 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1889 mtx_lock(&sync_mtx);
1890 LIST_REMOVE(bo, bo_synclist);
1891 syncer_worklist_len--;
1892 mtx_unlock(&sync_mtx);
1893 bo->bo_flag &= ~BO_ONWORKLST;
1894 }
1895 }
1896#ifdef INVARIANTS
1897 bv = &bo->bo_clean;
1898 bp = TAILQ_FIRST(&bv->bv_hd);
1899 KASSERT(bp == NULL || bp->b_bufobj == bo,
1900 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1901 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1902 KASSERT(bp == NULL || bp->b_bufobj == bo,
1903 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1904 bv = &bo->bo_dirty;
1905 bp = TAILQ_FIRST(&bv->bv_hd);
1906 KASSERT(bp == NULL || bp->b_bufobj == bo,
1907 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1908 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1909 KASSERT(bp == NULL || bp->b_bufobj == bo,
1910 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1911#endif
1912 VI_UNLOCK(vp);
1913}
1914
1915/*
1916 * Increment the use and hold counts on the vnode, taking care to reference
1917 * the driver's usecount if this is a chardev. The vholdl() will remove
1918 * the vnode from the free list if it is presently free. Requires the
1919 * vnode interlock and returns with it held.
1920 */
1921static void
1922v_incr_usecount(struct vnode *vp)
1923{
1924
1925 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n",
1926 vp, vp->v_holdcnt, vp->v_usecount);
1927 vp->v_usecount++;
1928 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1929 dev_lock();
1930 vp->v_rdev->si_usecount++;
1931 dev_unlock();
1932 }
1933 vholdl(vp);
1934}
1935
1936/*
1937 * Turn a holdcnt into a use+holdcnt such that only one call to
1938 * v_decr_usecount is needed.
1939 */
1940static void
1941v_upgrade_usecount(struct vnode *vp)
1942{
1943
1944 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n",
1945 vp, vp->v_holdcnt, vp->v_usecount);
1946 vp->v_usecount++;
1947 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1948 dev_lock();
1949 vp->v_rdev->si_usecount++;
1950 dev_unlock();
1951 }
1952}
1953
1954/*
1955 * Decrement the vnode use and hold count along with the driver's usecount
1956 * if this is a chardev. The vdropl() below releases the vnode interlock
1957 * as it may free the vnode.
1958 */
1959static void
1960v_decr_usecount(struct vnode *vp)
1961{
1962
1963 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n",
1964 vp, vp->v_holdcnt, vp->v_usecount);
1965 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1966 VNASSERT(vp->v_usecount > 0, vp,
1967 ("v_decr_usecount: negative usecount"));
1968 vp->v_usecount--;
1969 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1970 dev_lock();
1971 vp->v_rdev->si_usecount--;
1972 dev_unlock();
1973 }
1974 vdropl(vp);
1975}
1976
1977/*
1978 * Decrement only the use count and driver use count. This is intended to
1979 * be paired with a follow on vdropl() to release the remaining hold count.
1980 * In this way we may vgone() a vnode with a 0 usecount without risk of
1981 * having it end up on a free list because the hold count is kept above 0.
1982 */
1983static void
1984v_decr_useonly(struct vnode *vp)
1985{
1986
1987 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n",
1988 vp, vp->v_holdcnt, vp->v_usecount);
1989 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1990 VNASSERT(vp->v_usecount > 0, vp,
1991 ("v_decr_useonly: negative usecount"));
1992 vp->v_usecount--;
1993 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1994 dev_lock();
1995 vp->v_rdev->si_usecount--;
1996 dev_unlock();
1997 }
1998}
1999
2000/*
2001 * Grab a particular vnode from the free list, increment its
2002 * reference count and lock it. The vnode lock bit is set if the
2003 * vnode is being eliminated in vgone. The process is awakened
2004 * when the transition is completed, and an error returned to
2005 * indicate that the vnode is no longer usable (possibly having
2006 * been changed to a new filesystem type).
2007 */
2008int
2009vget(struct vnode *vp, int flags, struct thread *td)
2010{
2011 int oweinact;
2012 int oldflags;
2013 int error;
2014
2015 error = 0;
2016 oldflags = flags;
2017 oweinact = 0;
2018 VFS_ASSERT_GIANT(vp->v_mount);
2019 if ((flags & LK_INTERLOCK) == 0)
2020 VI_LOCK(vp);
2021 /*
2022 * If the inactive call was deferred because vput() was called
2023 * with a shared lock, we have to do it here before another thread
2024 * gets a reference to data that should be dead.
2025 */
2026 if (vp->v_iflag & VI_OWEINACT) {
2027 if (flags & LK_NOWAIT) {
2028 VI_UNLOCK(vp);
2029 return (EBUSY);
2030 }
2031 flags &= ~LK_TYPE_MASK;
2032 flags |= LK_EXCLUSIVE;
2033 oweinact = 1;
2034 }
2035 vholdl(vp);
2036 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
2037 vdrop(vp);
2038 return (error);
2039 }
2040 VI_LOCK(vp);
2041 /* Upgrade our holdcnt to a usecount. */
2042 v_upgrade_usecount(vp);
2043 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2044 panic("vget: vn_lock failed to return ENOENT\n");
2045 if (oweinact) {
2046 if (vp->v_iflag & VI_OWEINACT)
2047 vinactive(vp, td);
2048 VI_UNLOCK(vp);
2049 if ((oldflags & LK_TYPE_MASK) == 0)
2050 VOP_UNLOCK(vp, 0, td);
2051 } else
2052 VI_UNLOCK(vp);
2053 return (0);
2054}
2055
2056/*
2057 * Increase the reference count of a vnode.
2058 */
2059void
2060vref(struct vnode *vp)
2061{
2062
2063 VI_LOCK(vp);
2064 v_incr_usecount(vp);
2065 VI_UNLOCK(vp);
2066}
2067
2068/*
2069 * Return reference count of a vnode.
2070 *
2071 * The results of this call are only guaranteed when some mechanism other
2072 * than the VI lock is used to stop other processes from gaining references
2073 * to the vnode. This may be the case if the caller holds the only reference.
2074 * This is also useful when stale data is acceptable as race conditions may
2075 * be accounted for by some other means.
2076 */
2077int
2078vrefcnt(struct vnode *vp)
2079{
2080 int usecnt;
2081
2082 VI_LOCK(vp);
2083 usecnt = vp->v_usecount;
2084 VI_UNLOCK(vp);
2085
2086 return (usecnt);
2087}
2088
2089
2090/*
2091 * Vnode put/release.
2092 * If count drops to zero, call inactive routine and return to freelist.
2093 */
2094void
2095vrele(struct vnode *vp)
2096{
2097 struct thread *td = curthread; /* XXX */
2098
2099 KASSERT(vp != NULL, ("vrele: null vp"));
2100 VFS_ASSERT_GIANT(vp->v_mount);
2101
2102 VI_LOCK(vp);
2103
2104 /* Skip this v_writecount check if we're going to panic below. */
2105 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2106 ("vrele: missed vn_close"));
2107
2108 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2109 vp->v_usecount == 1)) {
2110 v_decr_usecount(vp);
2111 return;
2112 }
2113 if (vp->v_usecount != 1) {
2114#ifdef DIAGNOSTIC
2115 vprint("vrele: negative ref count", vp);
2116#endif
2117 VI_UNLOCK(vp);
2118 panic("vrele: negative ref cnt");
2119 }
2120 /*
2121 * We want to hold the vnode until the inactive finishes to
2122 * prevent vgone() races. We drop the use count here and the
2123 * hold count below when we're done.
2124 */
2125 v_decr_useonly(vp);
2126 /*
2127 * We must call VOP_INACTIVE with the node locked. Mark
2128 * as VI_DOINGINACT to avoid recursion.
2129 */
2130 vp->v_iflag |= VI_OWEINACT;
2131 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) {
2132 VI_LOCK(vp);
2133 if (vp->v_usecount > 0)
2134 vp->v_iflag &= ~VI_OWEINACT;
2135 if (vp->v_iflag & VI_OWEINACT)
2136 vinactive(vp, td);
2137 VOP_UNLOCK(vp, 0, td);
2138 } else {
2139 VI_LOCK(vp);
2140 if (vp->v_usecount > 0)
2141 vp->v_iflag &= ~VI_OWEINACT;
2142 }
2143 vdropl(vp);
2144}
2145
2146/*
2147 * Release an already locked vnode. This give the same effects as
2148 * unlock+vrele(), but takes less time and avoids releasing and
2149 * re-aquiring the lock (as vrele() aquires the lock internally.)
2150 */
2151void
2152vput(struct vnode *vp)
2153{
2154 struct thread *td = curthread; /* XXX */
2155 int error;
2156
2157 KASSERT(vp != NULL, ("vput: null vp"));
2158 ASSERT_VOP_LOCKED(vp, "vput");
2159 VFS_ASSERT_GIANT(vp->v_mount);
2160 VI_LOCK(vp);
2161 /* Skip this v_writecount check if we're going to panic below. */
2162 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2163 ("vput: missed vn_close"));
2164 error = 0;
2165
2166 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2167 vp->v_usecount == 1)) {
2168 VOP_UNLOCK(vp, 0, td);
2169 v_decr_usecount(vp);
2170 return;
2171 }
2172
2173 if (vp->v_usecount != 1) {
2174#ifdef DIAGNOSTIC
2175 vprint("vput: negative ref count", vp);
2176#endif
2177 panic("vput: negative ref cnt");
2178 }
2179 /*
2180 * We want to hold the vnode until the inactive finishes to
2181 * prevent vgone() races. We drop the use count here and the
2182 * hold count below when we're done.
2183 */
2184 v_decr_useonly(vp);
2185 vp->v_iflag |= VI_OWEINACT;
2186 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) {
2187 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td);
2188 VI_LOCK(vp);
2189 if (error) {
2190 if (vp->v_usecount > 0)
2191 vp->v_iflag &= ~VI_OWEINACT;
2192 goto done;
2193 }
2194 }
2195 if (vp->v_usecount > 0)
2196 vp->v_iflag &= ~VI_OWEINACT;
2197 if (vp->v_iflag & VI_OWEINACT)
2198 vinactive(vp, td);
2199 VOP_UNLOCK(vp, 0, td);
2200done:
2201 vdropl(vp);
2202}
2203
2204/*
2205 * Somebody doesn't want the vnode recycled.
2206 */
2207void
2208vhold(struct vnode *vp)
2209{
2210
2211 VI_LOCK(vp);
2212 vholdl(vp);
2213 VI_UNLOCK(vp);
2214}
2215
2216void
2217vholdl(struct vnode *vp)
2218{
2219
2220 vp->v_holdcnt++;
2221 if (VSHOULDBUSY(vp))
2222 vbusy(vp);
2223}
2224
2225/*
2226 * Note that there is one less who cares about this vnode. vdrop() is the
2227 * opposite of vhold().
2228 */
2229void
2230vdrop(struct vnode *vp)
2231{
2232
2233 VI_LOCK(vp);
2234 vdropl(vp);
2235}
2236
2237/*
2238 * Drop the hold count of the vnode. If this is the last reference to
2239 * the vnode we will free it if it has been vgone'd otherwise it is
2240 * placed on the free list.
2241 */
2242void
2243vdropl(struct vnode *vp)
2244{
2245
2246 ASSERT_VI_LOCKED(vp, "vdropl");
2247 if (vp->v_holdcnt <= 0)
2248 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2249 vp->v_holdcnt--;
2250 if (vp->v_holdcnt == 0) {
2251 if (vp->v_iflag & VI_DOOMED) {
2252 vdestroy(vp);
2253 return;
2254 } else
2255 vfree(vp);
2256 }
2257 VI_UNLOCK(vp);
2258}
2259
2260/*
2261 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2262 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2263 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2264 * failed lock upgrade.
2265 */
2266static void
2267vinactive(struct vnode *vp, struct thread *td)
2268{
2269
2270 ASSERT_VOP_LOCKED(vp, "vinactive");
2271 ASSERT_VI_LOCKED(vp, "vinactive");
2272 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2273 ("vinactive: recursed on VI_DOINGINACT"));
2274 vp->v_iflag |= VI_DOINGINACT;
2275 vp->v_iflag &= ~VI_OWEINACT;
2276 VI_UNLOCK(vp);
2277 VOP_INACTIVE(vp, td);
2278 VI_LOCK(vp);
2279 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2280 ("vinactive: lost VI_DOINGINACT"));
2281 vp->v_iflag &= ~VI_DOINGINACT;
2282}
2283
2284/*
2285 * Remove any vnodes in the vnode table belonging to mount point mp.
2286 *
2287 * If FORCECLOSE is not specified, there should not be any active ones,
2288 * return error if any are found (nb: this is a user error, not a
2289 * system error). If FORCECLOSE is specified, detach any active vnodes
2290 * that are found.
2291 *
2292 * If WRITECLOSE is set, only flush out regular file vnodes open for
2293 * writing.
2294 *
2295 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2296 *
2297 * `rootrefs' specifies the base reference count for the root vnode
2298 * of this filesystem. The root vnode is considered busy if its
2299 * v_usecount exceeds this value. On a successful return, vflush(, td)
2300 * will call vrele() on the root vnode exactly rootrefs times.
2301 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2302 * be zero.
2303 */
2304#ifdef DIAGNOSTIC
2305static int busyprt = 0; /* print out busy vnodes */
2306SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
2307#endif
2308
2309int
2310vflush( struct mount *mp, int rootrefs, int flags, struct thread *td)
2311{
2312 struct vnode *vp, *mvp, *rootvp = NULL;
2313 struct vattr vattr;
2314 int busy = 0, error;
2315
2316 CTR1(KTR_VFS, "vflush: mp %p", mp);
2317 if (rootrefs > 0) {
2318 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2319 ("vflush: bad args"));
2320 /*
2321 * Get the filesystem root vnode. We can vput() it
2322 * immediately, since with rootrefs > 0, it won't go away.
2323 */
2324 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0)
2325 return (error);
2326 vput(rootvp);
2327
2328 }
2329 MNT_ILOCK(mp);
2330loop:
2331 MNT_VNODE_FOREACH(vp, mp, mvp) {
2332
2333 VI_LOCK(vp);
2334 vholdl(vp);
2335 MNT_IUNLOCK(mp);
2336 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td);
2337 if (error) {
2338 vdrop(vp);
2339 MNT_ILOCK(mp);
2340 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
2341 goto loop;
2342 }
2343 /*
2344 * Skip over a vnodes marked VV_SYSTEM.
2345 */
2346 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2347 VOP_UNLOCK(vp, 0, td);
2348 vdrop(vp);
2349 MNT_ILOCK(mp);
2350 continue;
2351 }
2352 /*
2353 * If WRITECLOSE is set, flush out unlinked but still open
2354 * files (even if open only for reading) and regular file
2355 * vnodes open for writing.
2356 */
2357 if (flags & WRITECLOSE) {
2358 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td);
2359 VI_LOCK(vp);
2360
2361 if ((vp->v_type == VNON ||
2362 (error == 0 && vattr.va_nlink > 0)) &&
2363 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2364 VOP_UNLOCK(vp, 0, td);
2365 vdropl(vp);
2366 MNT_ILOCK(mp);
2367 continue;
2368 }
2369 } else
2370 VI_LOCK(vp);
2371 /*
2372 * With v_usecount == 0, all we need to do is clear out the
2373 * vnode data structures and we are done.
2374 *
2375 * If FORCECLOSE is set, forcibly close the vnode.
2376 */
2377 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2378 VNASSERT(vp->v_usecount == 0 ||
2379 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2380 ("device VNODE %p is FORCECLOSED", vp));
2381 vgonel(vp);
2382 } else {
2383 busy++;
2384#ifdef DIAGNOSTIC
2385 if (busyprt)
2386 vprint("vflush: busy vnode", vp);
2387#endif
2388 }
2389 VOP_UNLOCK(vp, 0, td);
2390 vdropl(vp);
2391 MNT_ILOCK(mp);
2392 }
2393 MNT_IUNLOCK(mp);
2394 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2395 /*
2396 * If just the root vnode is busy, and if its refcount
2397 * is equal to `rootrefs', then go ahead and kill it.
2398 */
2399 VI_LOCK(rootvp);
2400 KASSERT(busy > 0, ("vflush: not busy"));
2401 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2402 ("vflush: usecount %d < rootrefs %d",
2403 rootvp->v_usecount, rootrefs));
2404 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2405 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td);
2406 vgone(rootvp);
2407 VOP_UNLOCK(rootvp, 0, td);
2408 busy = 0;
2409 } else
2410 VI_UNLOCK(rootvp);
2411 }
2412 if (busy)
2413 return (EBUSY);
2414 for (; rootrefs > 0; rootrefs--)
2415 vrele(rootvp);
2416 return (0);
2417}
2418
2419/*
2420 * Recycle an unused vnode to the front of the free list.
2421 */
2422int
2423vrecycle(struct vnode *vp, struct thread *td)
2424{
2425 int recycled;
2426
2427 ASSERT_VOP_LOCKED(vp, "vrecycle");
2428 recycled = 0;
2429 VI_LOCK(vp);
2430 if (vp->v_usecount == 0) {
2431 recycled = 1;
2432 vgonel(vp);
2433 }
2434 VI_UNLOCK(vp);
2435 return (recycled);
2436}
2437
2438/*
2439 * Eliminate all activity associated with a vnode
2440 * in preparation for reuse.
2441 */
2442void
2443vgone(struct vnode *vp)
2444{
2445 VI_LOCK(vp);
2446 vgonel(vp);
2447 VI_UNLOCK(vp);
2448}
2449
2450/*
2451 * vgone, with the vp interlock held.
2452 */
2453void
2454vgonel(struct vnode *vp)
2455{
2456 struct thread *td;
2457 int oweinact;
2458 int active;
2459 struct mount *mp;
2460
2461 CTR1(KTR_VFS, "vgonel: vp %p", vp);
2462 ASSERT_VOP_LOCKED(vp, "vgonel");
2463 ASSERT_VI_LOCKED(vp, "vgonel");
2464 VNASSERT(vp->v_holdcnt, vp,
2465 ("vgonel: vp %p has no reference.", vp));
2466 td = curthread;
2467
2468 /*
2469 * Don't vgonel if we're already doomed.
2470 */
2471 if (vp->v_iflag & VI_DOOMED)
2472 return;
2473 vp->v_iflag |= VI_DOOMED;
2474 /*
2475 * Check to see if the vnode is in use. If so, we have to call
2476 * VOP_CLOSE() and VOP_INACTIVE().
2477 */
2478 active = vp->v_usecount;
2479 oweinact = (vp->v_iflag & VI_OWEINACT);
2480 VI_UNLOCK(vp);
2481 /*
2482 * Clean out any buffers associated with the vnode.
2483 * If the flush fails, just toss the buffers.
2484 */
2485 mp = NULL;
2486 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2487 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2488 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0)
2489 vinvalbuf(vp, 0, td, 0, 0);
2490
2491 /*
2492 * If purging an active vnode, it must be closed and
2493 * deactivated before being reclaimed.
2494 */
2495 if (active)
2496 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2497 if (oweinact || active) {
2498 VI_LOCK(vp);
2499 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2500 vinactive(vp, td);
2501 VI_UNLOCK(vp);
2502 }
2503 /*
2504 * Reclaim the vnode.
2505 */
2506 if (VOP_RECLAIM(vp, td))
2507 panic("vgone: cannot reclaim");
2508 if (mp != NULL)
2509 vn_finished_secondary_write(mp);
2510 VNASSERT(vp->v_object == NULL, vp,
2511 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2512 /*
2513 * Delete from old mount point vnode list.
2514 */
2515 delmntque(vp);
2516 cache_purge(vp);
2517 /*
2518 * Done with purge, reset to the standard lock and invalidate
2519 * the vnode.
2520 */
2521 VI_LOCK(vp);
2522 vp->v_vnlock = &vp->v_lock;
2523 vp->v_op = &dead_vnodeops;
2524 vp->v_tag = "none";
2525 vp->v_type = VBAD;
2526}
2527
2528/*
2529 * Calculate the total number of references to a special device.
2530 */
2531int
2532vcount(struct vnode *vp)
2533{
2534 int count;
2535
2536 dev_lock();
2537 count = vp->v_rdev->si_usecount;
2538 dev_unlock();
2539 return (count);
2540}
2541
2542/*
2543 * Same as above, but using the struct cdev *as argument
2544 */
2545int
2546count_dev(struct cdev *dev)
2547{
2548 int count;
2549
2550 dev_lock();
2551 count = dev->si_usecount;
2552 dev_unlock();
2553 return(count);
2554}
2555
2556/*
2557 * Print out a description of a vnode.
2558 */
2559static char *typename[] =
2560{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2561 "VMARKER"};
2562
2563void
2564vn_printf(struct vnode *vp, const char *fmt, ...)
2565{
2566 va_list ap;
2567 char buf[96];
2568
2569 va_start(ap, fmt);
2570 vprintf(fmt, ap);
2571 va_end(ap);
2572 printf("%p: ", (void *)vp);
2573 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2574 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2575 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2576 buf[0] = '\0';
2577 buf[1] = '\0';
2578 if (vp->v_vflag & VV_ROOT)
2579 strcat(buf, "|VV_ROOT");
2580 if (vp->v_vflag & VV_TEXT)
2581 strcat(buf, "|VV_TEXT");
2582 if (vp->v_vflag & VV_SYSTEM)
2583 strcat(buf, "|VV_SYSTEM");
2584 if (vp->v_vflag & VV_DELETED)
2585 strcat(buf, "|VV_DELETED");
2586 if (vp->v_iflag & VI_DOOMED)
2587 strcat(buf, "|VI_DOOMED");
2588 if (vp->v_iflag & VI_FREE)
2589 strcat(buf, "|VI_FREE");
2590 printf(" flags (%s)\n", buf + 1);
2591 if (mtx_owned(VI_MTX(vp)))
2592 printf(" VI_LOCKed");
2593 if (vp->v_object != NULL)
2594 printf(" v_object %p ref %d pages %d\n",
2595 vp->v_object, vp->v_object->ref_count,
2596 vp->v_object->resident_page_count);
2597 printf(" ");
2598 lockmgr_printinfo(vp->v_vnlock);
2599 printf("\n");
2600 if (vp->v_data != NULL)
2601 VOP_PRINT(vp);
2602}
2603
2604#ifdef DDB
2605/*
2606 * List all of the locked vnodes in the system.
2607 * Called when debugging the kernel.
2608 */
2609DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2610{
2611 struct mount *mp, *nmp;
2612 struct vnode *vp;
2613
2614 /*
2615 * Note: because this is DDB, we can't obey the locking semantics
2616 * for these structures, which means we could catch an inconsistent
2617 * state and dereference a nasty pointer. Not much to be done
2618 * about that.
2619 */
2620 printf("Locked vnodes\n");
2621 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2622 nmp = TAILQ_NEXT(mp, mnt_list);
2623 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2624 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL))
2625 vprint("", vp);
2626 }
2627 nmp = TAILQ_NEXT(mp, mnt_list);
2628 }
2629}
2630
2631/*
2632 * Show details about the given vnode.
2633 */
2634DB_SHOW_COMMAND(vnode, db_show_vnode)
2635{
2636 struct vnode *vp;
2637
2638 if (!have_addr)
2639 return;
2640 vp = (struct vnode *)addr;
2641 vn_printf(vp, "vnode ");
2642}
2643#endif /* DDB */
2644
2645/*
2646 * Fill in a struct xvfsconf based on a struct vfsconf.
2647 */
2648static void
2649vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
2650{
2651
2652 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
2653 xvfsp->vfc_typenum = vfsp->vfc_typenum;
2654 xvfsp->vfc_refcount = vfsp->vfc_refcount;
2655 xvfsp->vfc_flags = vfsp->vfc_flags;
2656 /*
2657 * These are unused in userland, we keep them
2658 * to not break binary compatibility.
2659 */
2660 xvfsp->vfc_vfsops = NULL;
2661 xvfsp->vfc_next = NULL;
2662}
2663
2664/*
2665 * Top level filesystem related information gathering.
2666 */
2667static int
2668sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
2669{
2670 struct vfsconf *vfsp;
2671 struct xvfsconf xvfsp;
2672 int error;
2673
2674 error = 0;
2675 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2676 bzero(&xvfsp, sizeof(xvfsp));
2677 vfsconf2x(vfsp, &xvfsp);
2678 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
2679 if (error)
2680 break;
2681 }
2682 return (error);
2683}
2684
2685SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist,
2686 "S,xvfsconf", "List of all configured filesystems");
2687
2688#ifndef BURN_BRIDGES
2689static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
2690
2691static int
2692vfs_sysctl(SYSCTL_HANDLER_ARGS)
2693{
2694 int *name = (int *)arg1 - 1; /* XXX */
2695 u_int namelen = arg2 + 1; /* XXX */
2696 struct vfsconf *vfsp;
2697 struct xvfsconf xvfsp;
2698
2699 printf("WARNING: userland calling deprecated sysctl, "
2700 "please rebuild world\n");
2701
2702#if 1 || defined(COMPAT_PRELITE2)
2703 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
2704 if (namelen == 1)
2705 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
2706#endif
2707
2708 switch (name[1]) {
2709 case VFS_MAXTYPENUM:
2710 if (namelen != 2)
2711 return (ENOTDIR);
2712 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
2713 case VFS_CONF:
2714 if (namelen != 3)
2715 return (ENOTDIR); /* overloaded */
2716 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
2717 if (vfsp->vfc_typenum == name[2])
2718 break;
2719 if (vfsp == NULL)
2720 return (EOPNOTSUPP);
2721 bzero(&xvfsp, sizeof(xvfsp));
2722 vfsconf2x(vfsp, &xvfsp);
2723 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
2724 }
2725 return (EOPNOTSUPP);
2726}
2727
2728static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
2729 vfs_sysctl, "Generic filesystem");
2730
2731#if 1 || defined(COMPAT_PRELITE2)
2732
2733static int
2734sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
2735{
2736 int error;
2737 struct vfsconf *vfsp;
2738 struct ovfsconf ovfs;
2739
2740 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2741 bzero(&ovfs, sizeof(ovfs));
2742 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
2743 strcpy(ovfs.vfc_name, vfsp->vfc_name);
2744 ovfs.vfc_index = vfsp->vfc_typenum;
2745 ovfs.vfc_refcount = vfsp->vfc_refcount;
2746 ovfs.vfc_flags = vfsp->vfc_flags;
2747 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
2748 if (error)
2749 return error;
2750 }
2751 return 0;
2752}
2753
2754#endif /* 1 || COMPAT_PRELITE2 */
2755#endif /* !BURN_BRIDGES */
2756
2757#define KINFO_VNODESLOP 10
2758#ifdef notyet
2759/*
2760 * Dump vnode list (via sysctl).
2761 */
2762/* ARGSUSED */
2763static int
2764sysctl_vnode(SYSCTL_HANDLER_ARGS)
2765{
2766 struct xvnode *xvn;
2767 struct thread *td = req->td;
2768 struct mount *mp;
2769 struct vnode *vp;
2770 int error, len, n;
2771
2772 /*
2773 * Stale numvnodes access is not fatal here.
2774 */
2775 req->lock = 0;
2776 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
2777 if (!req->oldptr)
2778 /* Make an estimate */
2779 return (SYSCTL_OUT(req, 0, len));
2780
2781 error = sysctl_wire_old_buffer(req, 0);
2782 if (error != 0)
2783 return (error);
2784 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
2785 n = 0;
2786 mtx_lock(&mountlist_mtx);
2787 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2788 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td))
2789 continue;
2790 MNT_ILOCK(mp);
2791 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2792 if (n == len)
2793 break;
2794 vref(vp);
2795 xvn[n].xv_size = sizeof *xvn;
2796 xvn[n].xv_vnode = vp;
2797 xvn[n].xv_id = 0; /* XXX compat */
2798#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
2799 XV_COPY(usecount);
2800 XV_COPY(writecount);
2801 XV_COPY(holdcnt);
2802 XV_COPY(mount);
2803 XV_COPY(numoutput);
2804 XV_COPY(type);
2805#undef XV_COPY
2806 xvn[n].xv_flag = vp->v_vflag;
2807
2808 switch (vp->v_type) {
2809 case VREG:
2810 case VDIR:
2811 case VLNK:
2812 break;
2813 case VBLK:
2814 case VCHR:
2815 if (vp->v_rdev == NULL) {
2816 vrele(vp);
2817 continue;
2818 }
2819 xvn[n].xv_dev = dev2udev(vp->v_rdev);
2820 break;
2821 case VSOCK:
2822 xvn[n].xv_socket = vp->v_socket;
2823 break;
2824 case VFIFO:
2825 xvn[n].xv_fifo = vp->v_fifoinfo;
2826 break;
2827 case VNON:
2828 case VBAD:
2829 default:
2830 /* shouldn't happen? */
2831 vrele(vp);
2832 continue;
2833 }
2834 vrele(vp);
2835 ++n;
2836 }
2837 MNT_IUNLOCK(mp);
2838 mtx_lock(&mountlist_mtx);
2839 vfs_unbusy(mp, td);
2840 if (n == len)
2841 break;
2842 }
2843 mtx_unlock(&mountlist_mtx);
2844
2845 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
2846 free(xvn, M_TEMP);
2847 return (error);
2848}
2849
2850SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
2851 0, 0, sysctl_vnode, "S,xvnode", "");
2852#endif
2853
2854/*
2855 * Unmount all filesystems. The list is traversed in reverse order
2856 * of mounting to avoid dependencies.
2857 */
2858void
2859vfs_unmountall(void)
2860{
2861 struct mount *mp;
2862 struct thread *td;
2863 int error;
2864
2865 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
2866 td = curthread;
2867 /*
2868 * Since this only runs when rebooting, it is not interlocked.
2869 */
2870 while(!TAILQ_EMPTY(&mountlist)) {
2871 mp = TAILQ_LAST(&mountlist, mntlist);
2872 error = dounmount(mp, MNT_FORCE, td);
2873 if (error) {
2874 TAILQ_REMOVE(&mountlist, mp, mnt_list);
2875 /*
2876 * XXX: Due to the way in which we mount the root
2877 * file system off of devfs, devfs will generate a
2878 * "busy" warning when we try to unmount it before
2879 * the root. Don't print a warning as a result in
2880 * order to avoid false positive errors that may
2881 * cause needless upset.
2882 */
2883 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
2884 printf("unmount of %s failed (",
2885 mp->mnt_stat.f_mntonname);
2886 if (error == EBUSY)
2887 printf("BUSY)\n");
2888 else
2889 printf("%d)\n", error);
2890 }
2891 } else {
2892 /* The unmount has removed mp from the mountlist */
2893 }
2894 }
2895}
2896
2897/*
2898 * perform msync on all vnodes under a mount point
2899 * the mount point must be locked.
2900 */
2901void
2902vfs_msync(struct mount *mp, int flags)
2903{
2904 struct vnode *vp, *mvp;
2905 struct vm_object *obj;
2906
2907 MNT_ILOCK(mp);
2908 MNT_VNODE_FOREACH(vp, mp, mvp) {
2909 VI_LOCK(vp);
2910 if ((vp->v_iflag & VI_OBJDIRTY) &&
2911 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
2912 MNT_IUNLOCK(mp);
2913 if (!vget(vp,
2914 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
2915 curthread)) {
2916 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
2917 vput(vp);
2918 MNT_ILOCK(mp);
2919 continue;
2920 }
2921
2922 obj = vp->v_object;
2923 if (obj != NULL) {
2924 VM_OBJECT_LOCK(obj);
2925 vm_object_page_clean(obj, 0, 0,
2926 flags == MNT_WAIT ?
2927 OBJPC_SYNC : OBJPC_NOSYNC);
2928 VM_OBJECT_UNLOCK(obj);
2929 }
2930 vput(vp);
2931 }
2932 MNT_ILOCK(mp);
2933 } else
2934 VI_UNLOCK(vp);
2935 }
2936 MNT_IUNLOCK(mp);
2937}
2938
2939/*
2940 * Mark a vnode as free, putting it up for recycling.
2941 */
2942static void
2943vfree(struct vnode *vp)
2944{
2945
2946 CTR1(KTR_VFS, "vfree vp %p", vp);
2947 ASSERT_VI_LOCKED(vp, "vfree");
2948 mtx_lock(&vnode_free_list_mtx);
2949 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed."));
2950 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free"));
2951 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't"));
2952 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp,
2953 ("vfree: Freeing doomed vnode"));
2954 if (vp->v_iflag & VI_AGE) {
2955 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
2956 } else {
2957 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
2958 }
2959 freevnodes++;
2960 vp->v_iflag &= ~VI_AGE;
2961 vp->v_iflag |= VI_FREE;
2962 mtx_unlock(&vnode_free_list_mtx);
2963}
2964
2965/*
2966 * Opposite of vfree() - mark a vnode as in use.
2967 */
2968static void
2969vbusy(struct vnode *vp)
2970{
2971 CTR1(KTR_VFS, "vbusy vp %p", vp);
2972 ASSERT_VI_LOCKED(vp, "vbusy");
2973 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
2974 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed."));
2975
2976 mtx_lock(&vnode_free_list_mtx);
2977 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
2978 freevnodes--;
2979 vp->v_iflag &= ~(VI_FREE|VI_AGE);
2980 mtx_unlock(&vnode_free_list_mtx);
2981}
2982
2983/*
2984 * Initalize per-vnode helper structure to hold poll-related state.
2985 */
2986void
2987v_addpollinfo(struct vnode *vp)
2988{
2989 struct vpollinfo *vi;
2990
2991 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
2992 if (vp->v_pollinfo != NULL) {
2993 uma_zfree(vnodepoll_zone, vi);
2994 return;
2995 }
2996 vp->v_pollinfo = vi;
2997 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
2998 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock,
2999 vfs_knlunlock, vfs_knllocked);
3000}
3001
3002/*
3003 * Record a process's interest in events which might happen to
3004 * a vnode. Because poll uses the historic select-style interface
3005 * internally, this routine serves as both the ``check for any
3006 * pending events'' and the ``record my interest in future events''
3007 * functions. (These are done together, while the lock is held,
3008 * to avoid race conditions.)
3009 */
3010int
3011vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3012{
3013
3014 if (vp->v_pollinfo == NULL)
3015 v_addpollinfo(vp);
3016 mtx_lock(&vp->v_pollinfo->vpi_lock);
3017 if (vp->v_pollinfo->vpi_revents & events) {
3018 /*
3019 * This leaves events we are not interested
3020 * in available for the other process which
3021 * which presumably had requested them
3022 * (otherwise they would never have been
3023 * recorded).
3024 */
3025 events &= vp->v_pollinfo->vpi_revents;
3026 vp->v_pollinfo->vpi_revents &= ~events;
3027
3028 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3029 return events;
3030 }
3031 vp->v_pollinfo->vpi_events |= events;
3032 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3033 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3034 return 0;
3035}
3036
3037/*
3038 * Routine to create and manage a filesystem syncer vnode.
3039 */
3040#define sync_close ((int (*)(struct vop_close_args *))nullop)
3041static int sync_fsync(struct vop_fsync_args *);
3042static int sync_inactive(struct vop_inactive_args *);
3043static int sync_reclaim(struct vop_reclaim_args *);
3044
3045static struct vop_vector sync_vnodeops = {
3046 .vop_bypass = VOP_EOPNOTSUPP,
3047 .vop_close = sync_close, /* close */
3048 .vop_fsync = sync_fsync, /* fsync */
3049 .vop_inactive = sync_inactive, /* inactive */
3050 .vop_reclaim = sync_reclaim, /* reclaim */
| 43
44#include "opt_ddb.h"
45#include "opt_mac.h"
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/bio.h>
50#include <sys/buf.h>
51#include <sys/conf.h>
52#include <sys/dirent.h>
53#include <sys/event.h>
54#include <sys/eventhandler.h>
55#include <sys/extattr.h>
56#include <sys/file.h>
57#include <sys/fcntl.h>
58#include <sys/jail.h>
59#include <sys/kdb.h>
60#include <sys/kernel.h>
61#include <sys/kthread.h>
62#include <sys/malloc.h>
63#include <sys/mount.h>
64#include <sys/namei.h>
65#include <sys/priv.h>
66#include <sys/reboot.h>
67#include <sys/sleepqueue.h>
68#include <sys/stat.h>
69#include <sys/sysctl.h>
70#include <sys/syslog.h>
71#include <sys/vmmeter.h>
72#include <sys/vnode.h>
73
74#include <machine/stdarg.h>
75
76#include <security/mac/mac_framework.h>
77
78#include <vm/vm.h>
79#include <vm/vm_object.h>
80#include <vm/vm_extern.h>
81#include <vm/pmap.h>
82#include <vm/vm_map.h>
83#include <vm/vm_page.h>
84#include <vm/vm_kern.h>
85#include <vm/uma.h>
86
87#ifdef DDB
88#include <ddb/ddb.h>
89#endif
90
91static MALLOC_DEFINE(M_NETADDR, "subr_export_host", "Export host address structure");
92
93static void delmntque(struct vnode *vp);
94static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
95 int slpflag, int slptimeo);
96static void syncer_shutdown(void *arg, int howto);
97static int vtryrecycle(struct vnode *vp);
98static void vbusy(struct vnode *vp);
99static void vinactive(struct vnode *, struct thread *);
100static void v_incr_usecount(struct vnode *);
101static void v_decr_usecount(struct vnode *);
102static void v_decr_useonly(struct vnode *);
103static void v_upgrade_usecount(struct vnode *);
104static void vfree(struct vnode *);
105static void vnlru_free(int);
106static void vdestroy(struct vnode *);
107static void vgonel(struct vnode *);
108static void vfs_knllock(void *arg);
109static void vfs_knlunlock(void *arg);
110static int vfs_knllocked(void *arg);
111
112
113/*
114 * Enable Giant pushdown based on whether or not the vm is mpsafe in this
115 * build. Without mpsafevm the buffer cache can not run Giant free.
116 */
117int mpsafe_vfs = 1;
118TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs);
119SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0,
120 "MPSAFE VFS");
121
122/*
123 * Number of vnodes in existence. Increased whenever getnewvnode()
124 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed
125 * vnode.
126 */
127static unsigned long numvnodes;
128
129SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
130
131/*
132 * Conversion tables for conversion from vnode types to inode formats
133 * and back.
134 */
135enum vtype iftovt_tab[16] = {
136 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
137 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
138};
139int vttoif_tab[10] = {
140 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
141 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
142};
143
144/*
145 * List of vnodes that are ready for recycling.
146 */
147static TAILQ_HEAD(freelst, vnode) vnode_free_list;
148
149/*
150 * Free vnode target. Free vnodes may simply be files which have been stat'd
151 * but not read. This is somewhat common, and a small cache of such files
152 * should be kept to avoid recreation costs.
153 */
154static u_long wantfreevnodes;
155SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
156/* Number of vnodes in the free list. */
157static u_long freevnodes;
158SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
159
160/*
161 * Various variables used for debugging the new implementation of
162 * reassignbuf().
163 * XXX these are probably of (very) limited utility now.
164 */
165static int reassignbufcalls;
166SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
167
168/*
169 * Cache for the mount type id assigned to NFS. This is used for
170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
171 */
172int nfs_mount_type = -1;
173
174/* To keep more than one thread at a time from running vfs_getnewfsid */
175static struct mtx mntid_mtx;
176
177/*
178 * Lock for any access to the following:
179 * vnode_free_list
180 * numvnodes
181 * freevnodes
182 */
183static struct mtx vnode_free_list_mtx;
184
185/* Publicly exported FS */
186struct nfs_public nfs_pub;
187
188/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
189static uma_zone_t vnode_zone;
190static uma_zone_t vnodepoll_zone;
191
192/* Set to 1 to print out reclaim of active vnodes */
193int prtactive;
194
195/*
196 * The workitem queue.
197 *
198 * It is useful to delay writes of file data and filesystem metadata
199 * for tens of seconds so that quickly created and deleted files need
200 * not waste disk bandwidth being created and removed. To realize this,
201 * we append vnodes to a "workitem" queue. When running with a soft
202 * updates implementation, most pending metadata dependencies should
203 * not wait for more than a few seconds. Thus, mounted on block devices
204 * are delayed only about a half the time that file data is delayed.
205 * Similarly, directory updates are more critical, so are only delayed
206 * about a third the time that file data is delayed. Thus, there are
207 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
208 * one each second (driven off the filesystem syncer process). The
209 * syncer_delayno variable indicates the next queue that is to be processed.
210 * Items that need to be processed soon are placed in this queue:
211 *
212 * syncer_workitem_pending[syncer_delayno]
213 *
214 * A delay of fifteen seconds is done by placing the request fifteen
215 * entries later in the queue:
216 *
217 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
218 *
219 */
220static int syncer_delayno;
221static long syncer_mask;
222LIST_HEAD(synclist, bufobj);
223static struct synclist *syncer_workitem_pending;
224/*
225 * The sync_mtx protects:
226 * bo->bo_synclist
227 * sync_vnode_count
228 * syncer_delayno
229 * syncer_state
230 * syncer_workitem_pending
231 * syncer_worklist_len
232 * rushjob
233 */
234static struct mtx sync_mtx;
235
236#define SYNCER_MAXDELAY 32
237static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
238static int syncdelay = 30; /* max time to delay syncing data */
239static int filedelay = 30; /* time to delay syncing files */
240SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, "");
241static int dirdelay = 29; /* time to delay syncing directories */
242SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, "");
243static int metadelay = 28; /* time to delay syncing metadata */
244SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, "");
245static int rushjob; /* number of slots to run ASAP */
246static int stat_rush_requests; /* number of times I/O speeded up */
247SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
248
249/*
250 * When shutting down the syncer, run it at four times normal speed.
251 */
252#define SYNCER_SHUTDOWN_SPEEDUP 4
253static int sync_vnode_count;
254static int syncer_worklist_len;
255static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
256 syncer_state;
257
258/*
259 * Number of vnodes we want to exist at any one time. This is mostly used
260 * to size hash tables in vnode-related code. It is normally not used in
261 * getnewvnode(), as wantfreevnodes is normally nonzero.)
262 *
263 * XXX desiredvnodes is historical cruft and should not exist.
264 */
265int desiredvnodes;
266SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
267 &desiredvnodes, 0, "Maximum number of vnodes");
268SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
269 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
270static int vnlru_nowhere;
271SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
272 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
273
274/*
275 * Macros to control when a vnode is freed and recycled. All require
276 * the vnode interlock.
277 */
278#define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
279#define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
280#define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
281
282
283/*
284 * Initialize the vnode management data structures.
285 */
286#ifndef MAXVNODES_MAX
287#define MAXVNODES_MAX 100000
288#endif
289static void
290vntblinit(void *dummy __unused)
291{
292
293 /*
294 * Desiredvnodes is a function of the physical memory size and
295 * the kernel's heap size. Specifically, desiredvnodes scales
296 * in proportion to the physical memory size until two fifths
297 * of the kernel's heap size is consumed by vnodes and vm
298 * objects.
299 */
300 desiredvnodes = min(maxproc + VMCNT_GET(page_count) / 4, 2 *
301 vm_kmem_size / (5 * (sizeof(struct vm_object) +
302 sizeof(struct vnode))));
303 if (desiredvnodes > MAXVNODES_MAX) {
304 if (bootverbose)
305 printf("Reducing kern.maxvnodes %d -> %d\n",
306 desiredvnodes, MAXVNODES_MAX);
307 desiredvnodes = MAXVNODES_MAX;
308 }
309 wantfreevnodes = desiredvnodes / 4;
310 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
311 TAILQ_INIT(&vnode_free_list);
312 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
313 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
314 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
315 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
316 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
317 /*
318 * Initialize the filesystem syncer.
319 */
320 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
321 &syncer_mask);
322 syncer_maxdelay = syncer_mask + 1;
323 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
324}
325SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL)
326
327
328/*
329 * Mark a mount point as busy. Used to synchronize access and to delay
330 * unmounting. Interlock is not released on failure.
331 */
332int
333vfs_busy(struct mount *mp, int flags, struct mtx *interlkp,
334 struct thread *td)
335{
336 int lkflags;
337
338 MNT_ILOCK(mp);
339 MNT_REF(mp);
340 if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
341 if (flags & LK_NOWAIT) {
342 MNT_REL(mp);
343 MNT_IUNLOCK(mp);
344 return (ENOENT);
345 }
346 if (interlkp)
347 mtx_unlock(interlkp);
348 mp->mnt_kern_flag |= MNTK_MWAIT;
349 /*
350 * Since all busy locks are shared except the exclusive
351 * lock granted when unmounting, the only place that a
352 * wakeup needs to be done is at the release of the
353 * exclusive lock at the end of dounmount.
354 */
355 msleep(mp, MNT_MTX(mp), PVFS, "vfs_busy", 0);
356 MNT_REL(mp);
357 MNT_IUNLOCK(mp);
358 if (interlkp)
359 mtx_lock(interlkp);
360 return (ENOENT);
361 }
362 if (interlkp)
363 mtx_unlock(interlkp);
364 lkflags = LK_SHARED | LK_INTERLOCK;
365 if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), td))
366 panic("vfs_busy: unexpected lock failure");
367 return (0);
368}
369
370/*
371 * Free a busy filesystem.
372 */
373void
374vfs_unbusy(struct mount *mp, struct thread *td)
375{
376
377 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
378 vfs_rel(mp);
379}
380
381/*
382 * Lookup a mount point by filesystem identifier.
383 */
384struct mount *
385vfs_getvfs(fsid_t *fsid)
386{
387 struct mount *mp;
388
389 mtx_lock(&mountlist_mtx);
390 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
391 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
392 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
393 vfs_ref(mp);
394 mtx_unlock(&mountlist_mtx);
395 return (mp);
396 }
397 }
398 mtx_unlock(&mountlist_mtx);
399 return ((struct mount *) 0);
400}
401
402/*
403 * Check if a user can access privileged mount options.
404 */
405int
406vfs_suser(struct mount *mp, struct thread *td)
407{
408 int error;
409
410 /*
411 * If the thread is jailed, but this is not a jail-friendly file
412 * system, deny immediately.
413 */
414 if (jailed(td->td_ucred) && !(mp->mnt_vfc->vfc_flags & VFCF_JAIL))
415 return (EPERM);
416
417 /*
418 * If the file system was mounted outside a jail and a jailed thread
419 * tries to access it, deny immediately.
420 */
421 if (!jailed(mp->mnt_cred) && jailed(td->td_ucred))
422 return (EPERM);
423
424 /*
425 * If the file system was mounted inside different jail that the jail of
426 * the calling thread, deny immediately.
427 */
428 if (jailed(mp->mnt_cred) && jailed(td->td_ucred) &&
429 mp->mnt_cred->cr_prison != td->td_ucred->cr_prison) {
430 return (EPERM);
431 }
432
433 if ((mp->mnt_flag & MNT_USER) == 0 ||
434 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
435 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
436 return (error);
437 }
438 return (0);
439}
440
441/*
442 * Get a new unique fsid. Try to make its val[0] unique, since this value
443 * will be used to create fake device numbers for stat(). Also try (but
444 * not so hard) make its val[0] unique mod 2^16, since some emulators only
445 * support 16-bit device numbers. We end up with unique val[0]'s for the
446 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
447 *
448 * Keep in mind that several mounts may be running in parallel. Starting
449 * the search one past where the previous search terminated is both a
450 * micro-optimization and a defense against returning the same fsid to
451 * different mounts.
452 */
453void
454vfs_getnewfsid(struct mount *mp)
455{
456 static u_int16_t mntid_base;
457 struct mount *nmp;
458 fsid_t tfsid;
459 int mtype;
460
461 mtx_lock(&mntid_mtx);
462 mtype = mp->mnt_vfc->vfc_typenum;
463 tfsid.val[1] = mtype;
464 mtype = (mtype & 0xFF) << 24;
465 for (;;) {
466 tfsid.val[0] = makedev(255,
467 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
468 mntid_base++;
469 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
470 break;
471 vfs_rel(nmp);
472 }
473 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
474 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
475 mtx_unlock(&mntid_mtx);
476}
477
478/*
479 * Knob to control the precision of file timestamps:
480 *
481 * 0 = seconds only; nanoseconds zeroed.
482 * 1 = seconds and nanoseconds, accurate within 1/HZ.
483 * 2 = seconds and nanoseconds, truncated to microseconds.
484 * >=3 = seconds and nanoseconds, maximum precision.
485 */
486enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
487
488static int timestamp_precision = TSP_SEC;
489SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
490 ×tamp_precision, 0, "");
491
492/*
493 * Get a current timestamp.
494 */
495void
496vfs_timestamp(struct timespec *tsp)
497{
498 struct timeval tv;
499
500 switch (timestamp_precision) {
501 case TSP_SEC:
502 tsp->tv_sec = time_second;
503 tsp->tv_nsec = 0;
504 break;
505 case TSP_HZ:
506 getnanotime(tsp);
507 break;
508 case TSP_USEC:
509 microtime(&tv);
510 TIMEVAL_TO_TIMESPEC(&tv, tsp);
511 break;
512 case TSP_NSEC:
513 default:
514 nanotime(tsp);
515 break;
516 }
517}
518
519/*
520 * Set vnode attributes to VNOVAL
521 */
522void
523vattr_null(struct vattr *vap)
524{
525
526 vap->va_type = VNON;
527 vap->va_size = VNOVAL;
528 vap->va_bytes = VNOVAL;
529 vap->va_mode = VNOVAL;
530 vap->va_nlink = VNOVAL;
531 vap->va_uid = VNOVAL;
532 vap->va_gid = VNOVAL;
533 vap->va_fsid = VNOVAL;
534 vap->va_fileid = VNOVAL;
535 vap->va_blocksize = VNOVAL;
536 vap->va_rdev = VNOVAL;
537 vap->va_atime.tv_sec = VNOVAL;
538 vap->va_atime.tv_nsec = VNOVAL;
539 vap->va_mtime.tv_sec = VNOVAL;
540 vap->va_mtime.tv_nsec = VNOVAL;
541 vap->va_ctime.tv_sec = VNOVAL;
542 vap->va_ctime.tv_nsec = VNOVAL;
543 vap->va_birthtime.tv_sec = VNOVAL;
544 vap->va_birthtime.tv_nsec = VNOVAL;
545 vap->va_flags = VNOVAL;
546 vap->va_gen = VNOVAL;
547 vap->va_vaflags = 0;
548}
549
550/*
551 * This routine is called when we have too many vnodes. It attempts
552 * to free <count> vnodes and will potentially free vnodes that still
553 * have VM backing store (VM backing store is typically the cause
554 * of a vnode blowout so we want to do this). Therefore, this operation
555 * is not considered cheap.
556 *
557 * A number of conditions may prevent a vnode from being reclaimed.
558 * the buffer cache may have references on the vnode, a directory
559 * vnode may still have references due to the namei cache representing
560 * underlying files, or the vnode may be in active use. It is not
561 * desireable to reuse such vnodes. These conditions may cause the
562 * number of vnodes to reach some minimum value regardless of what
563 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
564 */
565static int
566vlrureclaim(struct mount *mp)
567{
568 struct thread *td;
569 struct vnode *vp;
570 int done;
571 int trigger;
572 int usevnodes;
573 int count;
574
575 /*
576 * Calculate the trigger point, don't allow user
577 * screwups to blow us up. This prevents us from
578 * recycling vnodes with lots of resident pages. We
579 * aren't trying to free memory, we are trying to
580 * free vnodes.
581 */
582 usevnodes = desiredvnodes;
583 if (usevnodes <= 0)
584 usevnodes = 1;
585 trigger = VMCNT_GET(page_count) * 2 / usevnodes;
586 done = 0;
587 td = curthread;
588 vn_start_write(NULL, &mp, V_WAIT);
589 MNT_ILOCK(mp);
590 count = mp->mnt_nvnodelistsize / 10 + 1;
591 while (count != 0) {
592 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
593 while (vp != NULL && vp->v_type == VMARKER)
594 vp = TAILQ_NEXT(vp, v_nmntvnodes);
595 if (vp == NULL)
596 break;
597 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
598 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
599 --count;
600 if (!VI_TRYLOCK(vp))
601 goto next_iter;
602 /*
603 * If it's been deconstructed already, it's still
604 * referenced, or it exceeds the trigger, skip it.
605 */
606 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
607 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
608 vp->v_object->resident_page_count > trigger)) {
609 VI_UNLOCK(vp);
610 goto next_iter;
611 }
612 MNT_IUNLOCK(mp);
613 vholdl(vp);
614 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) {
615 vdrop(vp);
616 goto next_iter_mntunlocked;
617 }
618 VI_LOCK(vp);
619 /*
620 * v_usecount may have been bumped after VOP_LOCK() dropped
621 * the vnode interlock and before it was locked again.
622 *
623 * It is not necessary to recheck VI_DOOMED because it can
624 * only be set by another thread that holds both the vnode
625 * lock and vnode interlock. If another thread has the
626 * vnode lock before we get to VOP_LOCK() and obtains the
627 * vnode interlock after VOP_LOCK() drops the vnode
628 * interlock, the other thread will be unable to drop the
629 * vnode lock before our VOP_LOCK() call fails.
630 */
631 if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
632 (vp->v_object != NULL &&
633 vp->v_object->resident_page_count > trigger)) {
634 VOP_UNLOCK(vp, LK_INTERLOCK, td);
635 goto next_iter_mntunlocked;
636 }
637 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
638 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
639 vgonel(vp);
640 VOP_UNLOCK(vp, 0, td);
641 vdropl(vp);
642 done++;
643next_iter_mntunlocked:
644 if ((count % 256) != 0)
645 goto relock_mnt;
646 goto yield;
647next_iter:
648 if ((count % 256) != 0)
649 continue;
650 MNT_IUNLOCK(mp);
651yield:
652 uio_yield();
653relock_mnt:
654 MNT_ILOCK(mp);
655 }
656 MNT_IUNLOCK(mp);
657 vn_finished_write(mp);
658 return done;
659}
660
661/*
662 * Attempt to keep the free list at wantfreevnodes length.
663 */
664static void
665vnlru_free(int count)
666{
667 struct vnode *vp;
668 int vfslocked;
669
670 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
671 for (; count > 0; count--) {
672 vp = TAILQ_FIRST(&vnode_free_list);
673 /*
674 * The list can be modified while the free_list_mtx
675 * has been dropped and vp could be NULL here.
676 */
677 if (!vp)
678 break;
679 VNASSERT(vp->v_op != NULL, vp,
680 ("vnlru_free: vnode already reclaimed."));
681 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
682 /*
683 * Don't recycle if we can't get the interlock.
684 */
685 if (!VI_TRYLOCK(vp)) {
686 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
687 continue;
688 }
689 VNASSERT(VCANRECYCLE(vp), vp,
690 ("vp inconsistent on freelist"));
691 freevnodes--;
692 vp->v_iflag &= ~VI_FREE;
693 vholdl(vp);
694 mtx_unlock(&vnode_free_list_mtx);
695 VI_UNLOCK(vp);
696 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
697 vtryrecycle(vp);
698 VFS_UNLOCK_GIANT(vfslocked);
699 /*
700 * If the recycled succeeded this vdrop will actually free
701 * the vnode. If not it will simply place it back on
702 * the free list.
703 */
704 vdrop(vp);
705 mtx_lock(&vnode_free_list_mtx);
706 }
707}
708/*
709 * Attempt to recycle vnodes in a context that is always safe to block.
710 * Calling vlrurecycle() from the bowels of filesystem code has some
711 * interesting deadlock problems.
712 */
713static struct proc *vnlruproc;
714static int vnlruproc_sig;
715
716static void
717vnlru_proc(void)
718{
719 struct mount *mp, *nmp;
720 int done;
721 struct proc *p = vnlruproc;
722 struct thread *td = FIRST_THREAD_IN_PROC(p);
723
724 mtx_lock(&Giant);
725
726 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
727 SHUTDOWN_PRI_FIRST);
728
729 for (;;) {
730 kthread_suspend_check(p);
731 mtx_lock(&vnode_free_list_mtx);
732 if (freevnodes > wantfreevnodes)
733 vnlru_free(freevnodes - wantfreevnodes);
734 if (numvnodes <= desiredvnodes * 9 / 10) {
735 vnlruproc_sig = 0;
736 wakeup(&vnlruproc_sig);
737 msleep(vnlruproc, &vnode_free_list_mtx,
738 PVFS|PDROP, "vlruwt", hz);
739 continue;
740 }
741 mtx_unlock(&vnode_free_list_mtx);
742 done = 0;
743 mtx_lock(&mountlist_mtx);
744 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
745 int vfsunlocked;
746 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
747 nmp = TAILQ_NEXT(mp, mnt_list);
748 continue;
749 }
750 if (!VFS_NEEDSGIANT(mp)) {
751 mtx_unlock(&Giant);
752 vfsunlocked = 1;
753 } else
754 vfsunlocked = 0;
755 done += vlrureclaim(mp);
756 if (vfsunlocked)
757 mtx_lock(&Giant);
758 mtx_lock(&mountlist_mtx);
759 nmp = TAILQ_NEXT(mp, mnt_list);
760 vfs_unbusy(mp, td);
761 }
762 mtx_unlock(&mountlist_mtx);
763 if (done == 0) {
764 EVENTHANDLER_INVOKE(vfs_lowvnodes, desiredvnodes / 10);
765#if 0
766 /* These messages are temporary debugging aids */
767 if (vnlru_nowhere < 5)
768 printf("vnlru process getting nowhere..\n");
769 else if (vnlru_nowhere == 5)
770 printf("vnlru process messages stopped.\n");
771#endif
772 vnlru_nowhere++;
773 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
774 } else
775 uio_yield();
776 }
777}
778
779static struct kproc_desc vnlru_kp = {
780 "vnlru",
781 vnlru_proc,
782 &vnlruproc
783};
784SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp)
785
786/*
787 * Routines having to do with the management of the vnode table.
788 */
789
790static void
791vdestroy(struct vnode *vp)
792{
793 struct bufobj *bo;
794
795 CTR1(KTR_VFS, "vdestroy vp %p", vp);
796 mtx_lock(&vnode_free_list_mtx);
797 numvnodes--;
798 mtx_unlock(&vnode_free_list_mtx);
799 bo = &vp->v_bufobj;
800 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
801 ("cleaned vnode still on the free list."));
802 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
803 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
804 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
805 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
806 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
807 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
808 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
809 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
810 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
811 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
812 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
813 VI_UNLOCK(vp);
814#ifdef MAC
815 mac_destroy_vnode(vp);
816#endif
817 if (vp->v_pollinfo != NULL) {
818 knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note);
819 mtx_destroy(&vp->v_pollinfo->vpi_lock);
820 uma_zfree(vnodepoll_zone, vp->v_pollinfo);
821 }
822#ifdef INVARIANTS
823 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */
824 vp->v_op = NULL;
825#endif
826 lockdestroy(vp->v_vnlock);
827 mtx_destroy(&vp->v_interlock);
828 uma_zfree(vnode_zone, vp);
829}
830
831/*
832 * Try to recycle a freed vnode. We abort if anyone picks up a reference
833 * before we actually vgone(). This function must be called with the vnode
834 * held to prevent the vnode from being returned to the free list midway
835 * through vgone().
836 */
837static int
838vtryrecycle(struct vnode *vp)
839{
840 struct thread *td = curthread;
841 struct mount *vnmp;
842
843 CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp);
844 VNASSERT(vp->v_holdcnt, vp,
845 ("vtryrecycle: Recycling vp %p without a reference.", vp));
846 /*
847 * This vnode may found and locked via some other list, if so we
848 * can't recycle it yet.
849 */
850 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0)
851 return (EWOULDBLOCK);
852 /*
853 * Don't recycle if its filesystem is being suspended.
854 */
855 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
856 VOP_UNLOCK(vp, 0, td);
857 return (EBUSY);
858 }
859 /*
860 * If we got this far, we need to acquire the interlock and see if
861 * anyone picked up this vnode from another list. If not, we will
862 * mark it with DOOMED via vgonel() so that anyone who does find it
863 * will skip over it.
864 */
865 VI_LOCK(vp);
866 if (vp->v_usecount) {
867 VOP_UNLOCK(vp, LK_INTERLOCK, td);
868 vn_finished_write(vnmp);
869 return (EBUSY);
870 }
871 if ((vp->v_iflag & VI_DOOMED) == 0)
872 vgonel(vp);
873 VOP_UNLOCK(vp, LK_INTERLOCK, td);
874 vn_finished_write(vnmp);
875 CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp);
876 return (0);
877}
878
879/*
880 * Return the next vnode from the free list.
881 */
882int
883getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
884 struct vnode **vpp)
885{
886 struct vnode *vp = NULL;
887 struct bufobj *bo;
888
889 mtx_lock(&vnode_free_list_mtx);
890 /*
891 * Lend our context to reclaim vnodes if they've exceeded the max.
892 */
893 if (freevnodes > wantfreevnodes)
894 vnlru_free(1);
895 /*
896 * Wait for available vnodes.
897 */
898 if (numvnodes > desiredvnodes) {
899 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
900 /*
901 * File system is beeing suspended, we cannot risk a
902 * deadlock here, so allocate new vnode anyway.
903 */
904 if (freevnodes > wantfreevnodes)
905 vnlru_free(freevnodes - wantfreevnodes);
906 goto alloc;
907 }
908 if (vnlruproc_sig == 0) {
909 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
910 wakeup(vnlruproc);
911 }
912 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
913 "vlruwk", hz);
914#if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
915 if (numvnodes > desiredvnodes) {
916 mtx_unlock(&vnode_free_list_mtx);
917 return (ENFILE);
918 }
919#endif
920 }
921alloc:
922 numvnodes++;
923 mtx_unlock(&vnode_free_list_mtx);
924 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
925 /*
926 * Setup locks.
927 */
928 vp->v_vnlock = &vp->v_lock;
929 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
930 /*
931 * By default, don't allow shared locks unless filesystems
932 * opt-in.
933 */
934 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
935 /*
936 * Initialize bufobj.
937 */
938 bo = &vp->v_bufobj;
939 bo->__bo_vnode = vp;
940 bo->bo_mtx = &vp->v_interlock;
941 bo->bo_ops = &buf_ops_bio;
942 bo->bo_private = vp;
943 TAILQ_INIT(&bo->bo_clean.bv_hd);
944 TAILQ_INIT(&bo->bo_dirty.bv_hd);
945 /*
946 * Initialize namecache.
947 */
948 LIST_INIT(&vp->v_cache_src);
949 TAILQ_INIT(&vp->v_cache_dst);
950 /*
951 * Finalize various vnode identity bits.
952 */
953 vp->v_type = VNON;
954 vp->v_tag = tag;
955 vp->v_op = vops;
956 v_incr_usecount(vp);
957 vp->v_data = 0;
958#ifdef MAC
959 mac_init_vnode(vp);
960 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
961 mac_associate_vnode_singlelabel(mp, vp);
962 else if (mp == NULL)
963 printf("NULL mp in getnewvnode()\n");
964#endif
965 if (mp != NULL) {
966 bo->bo_bsize = mp->mnt_stat.f_iosize;
967 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
968 vp->v_vflag |= VV_NOKNOTE;
969 }
970
971 CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp);
972 *vpp = vp;
973 return (0);
974}
975
976/*
977 * Delete from old mount point vnode list, if on one.
978 */
979static void
980delmntque(struct vnode *vp)
981{
982 struct mount *mp;
983
984 mp = vp->v_mount;
985 if (mp == NULL)
986 return;
987 MNT_ILOCK(mp);
988 vp->v_mount = NULL;
989 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
990 ("bad mount point vnode list size"));
991 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
992 mp->mnt_nvnodelistsize--;
993 MNT_REL(mp);
994 MNT_IUNLOCK(mp);
995}
996
997static void
998insmntque_stddtr(struct vnode *vp, void *dtr_arg)
999{
1000 struct thread *td;
1001
1002 td = curthread; /* XXX ? */
1003 vp->v_data = NULL;
1004 vp->v_op = &dead_vnodeops;
1005 /* XXX non mp-safe fs may still call insmntque with vnode
1006 unlocked */
1007 if (!VOP_ISLOCKED(vp, td))
1008 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1009 vgone(vp);
1010 vput(vp);
1011}
1012
1013/*
1014 * Insert into list of vnodes for the new mount point, if available.
1015 */
1016int
1017insmntque1(struct vnode *vp, struct mount *mp,
1018 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1019{
1020
1021 KASSERT(vp->v_mount == NULL,
1022 ("insmntque: vnode already on per mount vnode list"));
1023 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1024 MNT_ILOCK(mp);
1025 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
1026 mp->mnt_nvnodelistsize == 0) {
1027 MNT_IUNLOCK(mp);
1028 if (dtr != NULL)
1029 dtr(vp, dtr_arg);
1030 return (EBUSY);
1031 }
1032 vp->v_mount = mp;
1033 MNT_REF(mp);
1034 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1035 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1036 ("neg mount point vnode list size"));
1037 mp->mnt_nvnodelistsize++;
1038 MNT_IUNLOCK(mp);
1039 return (0);
1040}
1041
1042int
1043insmntque(struct vnode *vp, struct mount *mp)
1044{
1045
1046 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1047}
1048
1049/*
1050 * Flush out and invalidate all buffers associated with a bufobj
1051 * Called with the underlying object locked.
1052 */
1053int
1054bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag,
1055 int slptimeo)
1056{
1057 int error;
1058
1059 BO_LOCK(bo);
1060 if (flags & V_SAVE) {
1061 error = bufobj_wwait(bo, slpflag, slptimeo);
1062 if (error) {
1063 BO_UNLOCK(bo);
1064 return (error);
1065 }
1066 if (bo->bo_dirty.bv_cnt > 0) {
1067 BO_UNLOCK(bo);
1068 if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0)
1069 return (error);
1070 /*
1071 * XXX We could save a lock/unlock if this was only
1072 * enabled under INVARIANTS
1073 */
1074 BO_LOCK(bo);
1075 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1076 panic("vinvalbuf: dirty bufs");
1077 }
1078 }
1079 /*
1080 * If you alter this loop please notice that interlock is dropped and
1081 * reacquired in flushbuflist. Special care is needed to ensure that
1082 * no race conditions occur from this.
1083 */
1084 do {
1085 error = flushbuflist(&bo->bo_clean,
1086 flags, bo, slpflag, slptimeo);
1087 if (error == 0)
1088 error = flushbuflist(&bo->bo_dirty,
1089 flags, bo, slpflag, slptimeo);
1090 if (error != 0 && error != EAGAIN) {
1091 BO_UNLOCK(bo);
1092 return (error);
1093 }
1094 } while (error != 0);
1095
1096 /*
1097 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1098 * have write I/O in-progress but if there is a VM object then the
1099 * VM object can also have read-I/O in-progress.
1100 */
1101 do {
1102 bufobj_wwait(bo, 0, 0);
1103 BO_UNLOCK(bo);
1104 if (bo->bo_object != NULL) {
1105 VM_OBJECT_LOCK(bo->bo_object);
1106 vm_object_pip_wait(bo->bo_object, "bovlbx");
1107 VM_OBJECT_UNLOCK(bo->bo_object);
1108 }
1109 BO_LOCK(bo);
1110 } while (bo->bo_numoutput > 0);
1111 BO_UNLOCK(bo);
1112
1113 /*
1114 * Destroy the copy in the VM cache, too.
1115 */
1116 if (bo->bo_object != NULL) {
1117 VM_OBJECT_LOCK(bo->bo_object);
1118 vm_object_page_remove(bo->bo_object, 0, 0,
1119 (flags & V_SAVE) ? TRUE : FALSE);
1120 VM_OBJECT_UNLOCK(bo->bo_object);
1121 }
1122
1123#ifdef INVARIANTS
1124 BO_LOCK(bo);
1125 if ((flags & (V_ALT | V_NORMAL)) == 0 &&
1126 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1127 panic("vinvalbuf: flush failed");
1128 BO_UNLOCK(bo);
1129#endif
1130 return (0);
1131}
1132
1133/*
1134 * Flush out and invalidate all buffers associated with a vnode.
1135 * Called with the underlying object locked.
1136 */
1137int
1138vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag,
1139 int slptimeo)
1140{
1141
1142 CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags);
1143 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1144 return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo));
1145}
1146
1147/*
1148 * Flush out buffers on the specified list.
1149 *
1150 */
1151static int
1152flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1153 int slptimeo)
1154{
1155 struct buf *bp, *nbp;
1156 int retval, error;
1157 daddr_t lblkno;
1158 b_xflags_t xflags;
1159
1160 ASSERT_BO_LOCKED(bo);
1161
1162 retval = 0;
1163 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1164 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1165 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1166 continue;
1167 }
1168 lblkno = 0;
1169 xflags = 0;
1170 if (nbp != NULL) {
1171 lblkno = nbp->b_lblkno;
1172 xflags = nbp->b_xflags &
1173 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1174 }
1175 retval = EAGAIN;
1176 error = BUF_TIMELOCK(bp,
1177 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1178 "flushbuf", slpflag, slptimeo);
1179 if (error) {
1180 BO_LOCK(bo);
1181 return (error != ENOLCK ? error : EAGAIN);
1182 }
1183 KASSERT(bp->b_bufobj == bo,
1184 ("bp %p wrong b_bufobj %p should be %p",
1185 bp, bp->b_bufobj, bo));
1186 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1187 BUF_UNLOCK(bp);
1188 BO_LOCK(bo);
1189 return (EAGAIN);
1190 }
1191 /*
1192 * XXX Since there are no node locks for NFS, I
1193 * believe there is a slight chance that a delayed
1194 * write will occur while sleeping just above, so
1195 * check for it.
1196 */
1197 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1198 (flags & V_SAVE)) {
1199 bremfree(bp);
1200 bp->b_flags |= B_ASYNC;
1201 bwrite(bp);
1202 BO_LOCK(bo);
1203 return (EAGAIN); /* XXX: why not loop ? */
1204 }
1205 bremfree(bp);
1206 bp->b_flags |= (B_INVAL | B_RELBUF);
1207 bp->b_flags &= ~B_ASYNC;
1208 brelse(bp);
1209 BO_LOCK(bo);
1210 if (nbp != NULL &&
1211 (nbp->b_bufobj != bo ||
1212 nbp->b_lblkno != lblkno ||
1213 (nbp->b_xflags &
1214 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1215 break; /* nbp invalid */
1216 }
1217 return (retval);
1218}
1219
1220/*
1221 * Truncate a file's buffer and pages to a specified length. This
1222 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1223 * sync activity.
1224 */
1225int
1226vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
1227 off_t length, int blksize)
1228{
1229 struct buf *bp, *nbp;
1230 int anyfreed;
1231 int trunclbn;
1232 struct bufobj *bo;
1233
1234 CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length);
1235 /*
1236 * Round up to the *next* lbn.
1237 */
1238 trunclbn = (length + blksize - 1) / blksize;
1239
1240 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1241restart:
1242 VI_LOCK(vp);
1243 bo = &vp->v_bufobj;
1244 anyfreed = 1;
1245 for (;anyfreed;) {
1246 anyfreed = 0;
1247 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1248 if (bp->b_lblkno < trunclbn)
1249 continue;
1250 if (BUF_LOCK(bp,
1251 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1252 VI_MTX(vp)) == ENOLCK)
1253 goto restart;
1254
1255 bremfree(bp);
1256 bp->b_flags |= (B_INVAL | B_RELBUF);
1257 bp->b_flags &= ~B_ASYNC;
1258 brelse(bp);
1259 anyfreed = 1;
1260
1261 if (nbp != NULL &&
1262 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1263 (nbp->b_vp != vp) ||
1264 (nbp->b_flags & B_DELWRI))) {
1265 goto restart;
1266 }
1267 VI_LOCK(vp);
1268 }
1269
1270 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1271 if (bp->b_lblkno < trunclbn)
1272 continue;
1273 if (BUF_LOCK(bp,
1274 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1275 VI_MTX(vp)) == ENOLCK)
1276 goto restart;
1277 bremfree(bp);
1278 bp->b_flags |= (B_INVAL | B_RELBUF);
1279 bp->b_flags &= ~B_ASYNC;
1280 brelse(bp);
1281 anyfreed = 1;
1282 if (nbp != NULL &&
1283 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1284 (nbp->b_vp != vp) ||
1285 (nbp->b_flags & B_DELWRI) == 0)) {
1286 goto restart;
1287 }
1288 VI_LOCK(vp);
1289 }
1290 }
1291
1292 if (length > 0) {
1293restartsync:
1294 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1295 if (bp->b_lblkno > 0)
1296 continue;
1297 /*
1298 * Since we hold the vnode lock this should only
1299 * fail if we're racing with the buf daemon.
1300 */
1301 if (BUF_LOCK(bp,
1302 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1303 VI_MTX(vp)) == ENOLCK) {
1304 goto restart;
1305 }
1306 VNASSERT((bp->b_flags & B_DELWRI), vp,
1307 ("buf(%p) on dirty queue without DELWRI", bp));
1308
1309 bremfree(bp);
1310 bawrite(bp);
1311 VI_LOCK(vp);
1312 goto restartsync;
1313 }
1314 }
1315
1316 bufobj_wwait(bo, 0, 0);
1317 VI_UNLOCK(vp);
1318 vnode_pager_setsize(vp, length);
1319
1320 return (0);
1321}
1322
1323/*
1324 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1325 * a vnode.
1326 *
1327 * NOTE: We have to deal with the special case of a background bitmap
1328 * buffer, a situation where two buffers will have the same logical
1329 * block offset. We want (1) only the foreground buffer to be accessed
1330 * in a lookup and (2) must differentiate between the foreground and
1331 * background buffer in the splay tree algorithm because the splay
1332 * tree cannot normally handle multiple entities with the same 'index'.
1333 * We accomplish this by adding differentiating flags to the splay tree's
1334 * numerical domain.
1335 */
1336static
1337struct buf *
1338buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1339{
1340 struct buf dummy;
1341 struct buf *lefttreemax, *righttreemin, *y;
1342
1343 if (root == NULL)
1344 return (NULL);
1345 lefttreemax = righttreemin = &dummy;
1346 for (;;) {
1347 if (lblkno < root->b_lblkno ||
1348 (lblkno == root->b_lblkno &&
1349 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1350 if ((y = root->b_left) == NULL)
1351 break;
1352 if (lblkno < y->b_lblkno) {
1353 /* Rotate right. */
1354 root->b_left = y->b_right;
1355 y->b_right = root;
1356 root = y;
1357 if ((y = root->b_left) == NULL)
1358 break;
1359 }
1360 /* Link into the new root's right tree. */
1361 righttreemin->b_left = root;
1362 righttreemin = root;
1363 } else if (lblkno > root->b_lblkno ||
1364 (lblkno == root->b_lblkno &&
1365 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1366 if ((y = root->b_right) == NULL)
1367 break;
1368 if (lblkno > y->b_lblkno) {
1369 /* Rotate left. */
1370 root->b_right = y->b_left;
1371 y->b_left = root;
1372 root = y;
1373 if ((y = root->b_right) == NULL)
1374 break;
1375 }
1376 /* Link into the new root's left tree. */
1377 lefttreemax->b_right = root;
1378 lefttreemax = root;
1379 } else {
1380 break;
1381 }
1382 root = y;
1383 }
1384 /* Assemble the new root. */
1385 lefttreemax->b_right = root->b_left;
1386 righttreemin->b_left = root->b_right;
1387 root->b_left = dummy.b_right;
1388 root->b_right = dummy.b_left;
1389 return (root);
1390}
1391
1392static void
1393buf_vlist_remove(struct buf *bp)
1394{
1395 struct buf *root;
1396 struct bufv *bv;
1397
1398 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1399 ASSERT_BO_LOCKED(bp->b_bufobj);
1400 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1401 (BX_VNDIRTY|BX_VNCLEAN),
1402 ("buf_vlist_remove: Buf %p is on two lists", bp));
1403 if (bp->b_xflags & BX_VNDIRTY)
1404 bv = &bp->b_bufobj->bo_dirty;
1405 else
1406 bv = &bp->b_bufobj->bo_clean;
1407 if (bp != bv->bv_root) {
1408 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1409 KASSERT(root == bp, ("splay lookup failed in remove"));
1410 }
1411 if (bp->b_left == NULL) {
1412 root = bp->b_right;
1413 } else {
1414 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1415 root->b_right = bp->b_right;
1416 }
1417 bv->bv_root = root;
1418 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1419 bv->bv_cnt--;
1420 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1421}
1422
1423/*
1424 * Add the buffer to the sorted clean or dirty block list using a
1425 * splay tree algorithm.
1426 *
1427 * NOTE: xflags is passed as a constant, optimizing this inline function!
1428 */
1429static void
1430buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1431{
1432 struct buf *root;
1433 struct bufv *bv;
1434
1435 ASSERT_BO_LOCKED(bo);
1436 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1437 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1438 bp->b_xflags |= xflags;
1439 if (xflags & BX_VNDIRTY)
1440 bv = &bo->bo_dirty;
1441 else
1442 bv = &bo->bo_clean;
1443
1444 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1445 if (root == NULL) {
1446 bp->b_left = NULL;
1447 bp->b_right = NULL;
1448 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1449 } else if (bp->b_lblkno < root->b_lblkno ||
1450 (bp->b_lblkno == root->b_lblkno &&
1451 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1452 bp->b_left = root->b_left;
1453 bp->b_right = root;
1454 root->b_left = NULL;
1455 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1456 } else {
1457 bp->b_right = root->b_right;
1458 bp->b_left = root;
1459 root->b_right = NULL;
1460 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1461 }
1462 bv->bv_cnt++;
1463 bv->bv_root = bp;
1464}
1465
1466/*
1467 * Lookup a buffer using the splay tree. Note that we specifically avoid
1468 * shadow buffers used in background bitmap writes.
1469 *
1470 * This code isn't quite efficient as it could be because we are maintaining
1471 * two sorted lists and do not know which list the block resides in.
1472 *
1473 * During a "make buildworld" the desired buffer is found at one of
1474 * the roots more than 60% of the time. Thus, checking both roots
1475 * before performing either splay eliminates unnecessary splays on the
1476 * first tree splayed.
1477 */
1478struct buf *
1479gbincore(struct bufobj *bo, daddr_t lblkno)
1480{
1481 struct buf *bp;
1482
1483 ASSERT_BO_LOCKED(bo);
1484 if ((bp = bo->bo_clean.bv_root) != NULL &&
1485 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1486 return (bp);
1487 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1488 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1489 return (bp);
1490 if ((bp = bo->bo_clean.bv_root) != NULL) {
1491 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1492 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1493 return (bp);
1494 }
1495 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1496 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1497 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1498 return (bp);
1499 }
1500 return (NULL);
1501}
1502
1503/*
1504 * Associate a buffer with a vnode.
1505 */
1506void
1507bgetvp(struct vnode *vp, struct buf *bp)
1508{
1509
1510 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1511
1512 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1513 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1514 ("bgetvp: bp already attached! %p", bp));
1515
1516 ASSERT_VI_LOCKED(vp, "bgetvp");
1517 vholdl(vp);
1518 if (VFS_NEEDSGIANT(vp->v_mount) ||
1519 vp->v_bufobj.bo_flag & BO_NEEDSGIANT)
1520 bp->b_flags |= B_NEEDSGIANT;
1521 bp->b_vp = vp;
1522 bp->b_bufobj = &vp->v_bufobj;
1523 /*
1524 * Insert onto list for new vnode.
1525 */
1526 buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN);
1527}
1528
1529/*
1530 * Disassociate a buffer from a vnode.
1531 */
1532void
1533brelvp(struct buf *bp)
1534{
1535 struct bufobj *bo;
1536 struct vnode *vp;
1537
1538 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1539 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1540
1541 /*
1542 * Delete from old vnode list, if on one.
1543 */
1544 vp = bp->b_vp; /* XXX */
1545 bo = bp->b_bufobj;
1546 BO_LOCK(bo);
1547 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1548 buf_vlist_remove(bp);
1549 else
1550 panic("brelvp: Buffer %p not on queue.", bp);
1551 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1552 bo->bo_flag &= ~BO_ONWORKLST;
1553 mtx_lock(&sync_mtx);
1554 LIST_REMOVE(bo, bo_synclist);
1555 syncer_worklist_len--;
1556 mtx_unlock(&sync_mtx);
1557 }
1558 bp->b_flags &= ~B_NEEDSGIANT;
1559 bp->b_vp = NULL;
1560 bp->b_bufobj = NULL;
1561 vdropl(vp);
1562}
1563
1564/*
1565 * Add an item to the syncer work queue.
1566 */
1567static void
1568vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1569{
1570 int slot;
1571
1572 ASSERT_BO_LOCKED(bo);
1573
1574 mtx_lock(&sync_mtx);
1575 if (bo->bo_flag & BO_ONWORKLST)
1576 LIST_REMOVE(bo, bo_synclist);
1577 else {
1578 bo->bo_flag |= BO_ONWORKLST;
1579 syncer_worklist_len++;
1580 }
1581
1582 if (delay > syncer_maxdelay - 2)
1583 delay = syncer_maxdelay - 2;
1584 slot = (syncer_delayno + delay) & syncer_mask;
1585
1586 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
1587 mtx_unlock(&sync_mtx);
1588}
1589
1590static int
1591sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1592{
1593 int error, len;
1594
1595 mtx_lock(&sync_mtx);
1596 len = syncer_worklist_len - sync_vnode_count;
1597 mtx_unlock(&sync_mtx);
1598 error = SYSCTL_OUT(req, &len, sizeof(len));
1599 return (error);
1600}
1601
1602SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1603 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1604
1605static struct proc *updateproc;
1606static void sched_sync(void);
1607static struct kproc_desc up_kp = {
1608 "syncer",
1609 sched_sync,
1610 &updateproc
1611};
1612SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
1613
1614static int
1615sync_vnode(struct bufobj *bo, struct thread *td)
1616{
1617 struct vnode *vp;
1618 struct mount *mp;
1619
1620 vp = bo->__bo_vnode; /* XXX */
1621 if (VOP_ISLOCKED(vp, NULL) != 0)
1622 return (1);
1623 if (VI_TRYLOCK(vp) == 0)
1624 return (1);
1625 /*
1626 * We use vhold in case the vnode does not
1627 * successfully sync. vhold prevents the vnode from
1628 * going away when we unlock the sync_mtx so that
1629 * we can acquire the vnode interlock.
1630 */
1631 vholdl(vp);
1632 mtx_unlock(&sync_mtx);
1633 VI_UNLOCK(vp);
1634 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1635 vdrop(vp);
1636 mtx_lock(&sync_mtx);
1637 return (1);
1638 }
1639 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1640 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1641 VOP_UNLOCK(vp, 0, td);
1642 vn_finished_write(mp);
1643 VI_LOCK(vp);
1644 if ((bo->bo_flag & BO_ONWORKLST) != 0) {
1645 /*
1646 * Put us back on the worklist. The worklist
1647 * routine will remove us from our current
1648 * position and then add us back in at a later
1649 * position.
1650 */
1651 vn_syncer_add_to_worklist(bo, syncdelay);
1652 }
1653 vdropl(vp);
1654 mtx_lock(&sync_mtx);
1655 return (0);
1656}
1657
1658/*
1659 * System filesystem synchronizer daemon.
1660 */
1661static void
1662sched_sync(void)
1663{
1664 struct synclist *next;
1665 struct synclist *slp;
1666 struct bufobj *bo;
1667 long starttime;
1668 struct thread *td = FIRST_THREAD_IN_PROC(updateproc);
1669 static int dummychan;
1670 int last_work_seen;
1671 int net_worklist_len;
1672 int syncer_final_iter;
1673 int first_printf;
1674 int error;
1675
1676 mtx_lock(&Giant);
1677 last_work_seen = 0;
1678 syncer_final_iter = 0;
1679 first_printf = 1;
1680 syncer_state = SYNCER_RUNNING;
1681 starttime = time_uptime;
1682 td->td_pflags |= TDP_NORUNNINGBUF;
1683
1684 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1685 SHUTDOWN_PRI_LAST);
1686
1687 mtx_lock(&sync_mtx);
1688 for (;;) {
1689 if (syncer_state == SYNCER_FINAL_DELAY &&
1690 syncer_final_iter == 0) {
1691 mtx_unlock(&sync_mtx);
1692 kthread_suspend_check(td->td_proc);
1693 mtx_lock(&sync_mtx);
1694 }
1695 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1696 if (syncer_state != SYNCER_RUNNING &&
1697 starttime != time_uptime) {
1698 if (first_printf) {
1699 printf("\nSyncing disks, vnodes remaining...");
1700 first_printf = 0;
1701 }
1702 printf("%d ", net_worklist_len);
1703 }
1704 starttime = time_uptime;
1705
1706 /*
1707 * Push files whose dirty time has expired. Be careful
1708 * of interrupt race on slp queue.
1709 *
1710 * Skip over empty worklist slots when shutting down.
1711 */
1712 do {
1713 slp = &syncer_workitem_pending[syncer_delayno];
1714 syncer_delayno += 1;
1715 if (syncer_delayno == syncer_maxdelay)
1716 syncer_delayno = 0;
1717 next = &syncer_workitem_pending[syncer_delayno];
1718 /*
1719 * If the worklist has wrapped since the
1720 * it was emptied of all but syncer vnodes,
1721 * switch to the FINAL_DELAY state and run
1722 * for one more second.
1723 */
1724 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1725 net_worklist_len == 0 &&
1726 last_work_seen == syncer_delayno) {
1727 syncer_state = SYNCER_FINAL_DELAY;
1728 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1729 }
1730 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1731 syncer_worklist_len > 0);
1732
1733 /*
1734 * Keep track of the last time there was anything
1735 * on the worklist other than syncer vnodes.
1736 * Return to the SHUTTING_DOWN state if any
1737 * new work appears.
1738 */
1739 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1740 last_work_seen = syncer_delayno;
1741 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1742 syncer_state = SYNCER_SHUTTING_DOWN;
1743 while ((bo = LIST_FIRST(slp)) != NULL) {
1744 error = sync_vnode(bo, td);
1745 if (error == 1) {
1746 LIST_REMOVE(bo, bo_synclist);
1747 LIST_INSERT_HEAD(next, bo, bo_synclist);
1748 continue;
1749 }
1750 }
1751 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1752 syncer_final_iter--;
1753 /*
1754 * The variable rushjob allows the kernel to speed up the
1755 * processing of the filesystem syncer process. A rushjob
1756 * value of N tells the filesystem syncer to process the next
1757 * N seconds worth of work on its queue ASAP. Currently rushjob
1758 * is used by the soft update code to speed up the filesystem
1759 * syncer process when the incore state is getting so far
1760 * ahead of the disk that the kernel memory pool is being
1761 * threatened with exhaustion.
1762 */
1763 if (rushjob > 0) {
1764 rushjob -= 1;
1765 continue;
1766 }
1767 /*
1768 * Just sleep for a short period of time between
1769 * iterations when shutting down to allow some I/O
1770 * to happen.
1771 *
1772 * If it has taken us less than a second to process the
1773 * current work, then wait. Otherwise start right over
1774 * again. We can still lose time if any single round
1775 * takes more than two seconds, but it does not really
1776 * matter as we are just trying to generally pace the
1777 * filesystem activity.
1778 */
1779 if (syncer_state != SYNCER_RUNNING)
1780 msleep(&dummychan, &sync_mtx, PPAUSE, "syncfnl",
1781 hz / SYNCER_SHUTDOWN_SPEEDUP);
1782 else if (time_uptime == starttime)
1783 msleep(&lbolt, &sync_mtx, PPAUSE, "syncer", 0);
1784 }
1785}
1786
1787/*
1788 * Request the syncer daemon to speed up its work.
1789 * We never push it to speed up more than half of its
1790 * normal turn time, otherwise it could take over the cpu.
1791 */
1792int
1793speedup_syncer(void)
1794{
1795 struct thread *td;
1796 int ret = 0;
1797
1798 td = FIRST_THREAD_IN_PROC(updateproc);
1799 sleepq_remove(td, &lbolt);
1800 mtx_lock(&sync_mtx);
1801 if (rushjob < syncdelay / 2) {
1802 rushjob += 1;
1803 stat_rush_requests += 1;
1804 ret = 1;
1805 }
1806 mtx_unlock(&sync_mtx);
1807 return (ret);
1808}
1809
1810/*
1811 * Tell the syncer to speed up its work and run though its work
1812 * list several times, then tell it to shut down.
1813 */
1814static void
1815syncer_shutdown(void *arg, int howto)
1816{
1817 struct thread *td;
1818
1819 if (howto & RB_NOSYNC)
1820 return;
1821 td = FIRST_THREAD_IN_PROC(updateproc);
1822 sleepq_remove(td, &lbolt);
1823 mtx_lock(&sync_mtx);
1824 syncer_state = SYNCER_SHUTTING_DOWN;
1825 rushjob = 0;
1826 mtx_unlock(&sync_mtx);
1827 kproc_shutdown(arg, howto);
1828}
1829
1830/*
1831 * Reassign a buffer from one vnode to another.
1832 * Used to assign file specific control information
1833 * (indirect blocks) to the vnode to which they belong.
1834 */
1835void
1836reassignbuf(struct buf *bp)
1837{
1838 struct vnode *vp;
1839 struct bufobj *bo;
1840 int delay;
1841#ifdef INVARIANTS
1842 struct bufv *bv;
1843#endif
1844
1845 vp = bp->b_vp;
1846 bo = bp->b_bufobj;
1847 ++reassignbufcalls;
1848
1849 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1850 bp, bp->b_vp, bp->b_flags);
1851 /*
1852 * B_PAGING flagged buffers cannot be reassigned because their vp
1853 * is not fully linked in.
1854 */
1855 if (bp->b_flags & B_PAGING)
1856 panic("cannot reassign paging buffer");
1857
1858 /*
1859 * Delete from old vnode list, if on one.
1860 */
1861 VI_LOCK(vp);
1862 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1863 buf_vlist_remove(bp);
1864 else
1865 panic("reassignbuf: Buffer %p not on queue.", bp);
1866 /*
1867 * If dirty, put on list of dirty buffers; otherwise insert onto list
1868 * of clean buffers.
1869 */
1870 if (bp->b_flags & B_DELWRI) {
1871 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
1872 switch (vp->v_type) {
1873 case VDIR:
1874 delay = dirdelay;
1875 break;
1876 case VCHR:
1877 delay = metadelay;
1878 break;
1879 default:
1880 delay = filedelay;
1881 }
1882 vn_syncer_add_to_worklist(bo, delay);
1883 }
1884 buf_vlist_add(bp, bo, BX_VNDIRTY);
1885 } else {
1886 buf_vlist_add(bp, bo, BX_VNCLEAN);
1887
1888 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1889 mtx_lock(&sync_mtx);
1890 LIST_REMOVE(bo, bo_synclist);
1891 syncer_worklist_len--;
1892 mtx_unlock(&sync_mtx);
1893 bo->bo_flag &= ~BO_ONWORKLST;
1894 }
1895 }
1896#ifdef INVARIANTS
1897 bv = &bo->bo_clean;
1898 bp = TAILQ_FIRST(&bv->bv_hd);
1899 KASSERT(bp == NULL || bp->b_bufobj == bo,
1900 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1901 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1902 KASSERT(bp == NULL || bp->b_bufobj == bo,
1903 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1904 bv = &bo->bo_dirty;
1905 bp = TAILQ_FIRST(&bv->bv_hd);
1906 KASSERT(bp == NULL || bp->b_bufobj == bo,
1907 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1908 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1909 KASSERT(bp == NULL || bp->b_bufobj == bo,
1910 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1911#endif
1912 VI_UNLOCK(vp);
1913}
1914
1915/*
1916 * Increment the use and hold counts on the vnode, taking care to reference
1917 * the driver's usecount if this is a chardev. The vholdl() will remove
1918 * the vnode from the free list if it is presently free. Requires the
1919 * vnode interlock and returns with it held.
1920 */
1921static void
1922v_incr_usecount(struct vnode *vp)
1923{
1924
1925 CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n",
1926 vp, vp->v_holdcnt, vp->v_usecount);
1927 vp->v_usecount++;
1928 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1929 dev_lock();
1930 vp->v_rdev->si_usecount++;
1931 dev_unlock();
1932 }
1933 vholdl(vp);
1934}
1935
1936/*
1937 * Turn a holdcnt into a use+holdcnt such that only one call to
1938 * v_decr_usecount is needed.
1939 */
1940static void
1941v_upgrade_usecount(struct vnode *vp)
1942{
1943
1944 CTR3(KTR_VFS, "v_upgrade_usecount: vp %p holdcnt %d usecount %d\n",
1945 vp, vp->v_holdcnt, vp->v_usecount);
1946 vp->v_usecount++;
1947 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1948 dev_lock();
1949 vp->v_rdev->si_usecount++;
1950 dev_unlock();
1951 }
1952}
1953
1954/*
1955 * Decrement the vnode use and hold count along with the driver's usecount
1956 * if this is a chardev. The vdropl() below releases the vnode interlock
1957 * as it may free the vnode.
1958 */
1959static void
1960v_decr_usecount(struct vnode *vp)
1961{
1962
1963 CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n",
1964 vp, vp->v_holdcnt, vp->v_usecount);
1965 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1966 VNASSERT(vp->v_usecount > 0, vp,
1967 ("v_decr_usecount: negative usecount"));
1968 vp->v_usecount--;
1969 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1970 dev_lock();
1971 vp->v_rdev->si_usecount--;
1972 dev_unlock();
1973 }
1974 vdropl(vp);
1975}
1976
1977/*
1978 * Decrement only the use count and driver use count. This is intended to
1979 * be paired with a follow on vdropl() to release the remaining hold count.
1980 * In this way we may vgone() a vnode with a 0 usecount without risk of
1981 * having it end up on a free list because the hold count is kept above 0.
1982 */
1983static void
1984v_decr_useonly(struct vnode *vp)
1985{
1986
1987 CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n",
1988 vp, vp->v_holdcnt, vp->v_usecount);
1989 ASSERT_VI_LOCKED(vp, __FUNCTION__);
1990 VNASSERT(vp->v_usecount > 0, vp,
1991 ("v_decr_useonly: negative usecount"));
1992 vp->v_usecount--;
1993 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
1994 dev_lock();
1995 vp->v_rdev->si_usecount--;
1996 dev_unlock();
1997 }
1998}
1999
2000/*
2001 * Grab a particular vnode from the free list, increment its
2002 * reference count and lock it. The vnode lock bit is set if the
2003 * vnode is being eliminated in vgone. The process is awakened
2004 * when the transition is completed, and an error returned to
2005 * indicate that the vnode is no longer usable (possibly having
2006 * been changed to a new filesystem type).
2007 */
2008int
2009vget(struct vnode *vp, int flags, struct thread *td)
2010{
2011 int oweinact;
2012 int oldflags;
2013 int error;
2014
2015 error = 0;
2016 oldflags = flags;
2017 oweinact = 0;
2018 VFS_ASSERT_GIANT(vp->v_mount);
2019 if ((flags & LK_INTERLOCK) == 0)
2020 VI_LOCK(vp);
2021 /*
2022 * If the inactive call was deferred because vput() was called
2023 * with a shared lock, we have to do it here before another thread
2024 * gets a reference to data that should be dead.
2025 */
2026 if (vp->v_iflag & VI_OWEINACT) {
2027 if (flags & LK_NOWAIT) {
2028 VI_UNLOCK(vp);
2029 return (EBUSY);
2030 }
2031 flags &= ~LK_TYPE_MASK;
2032 flags |= LK_EXCLUSIVE;
2033 oweinact = 1;
2034 }
2035 vholdl(vp);
2036 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
2037 vdrop(vp);
2038 return (error);
2039 }
2040 VI_LOCK(vp);
2041 /* Upgrade our holdcnt to a usecount. */
2042 v_upgrade_usecount(vp);
2043 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2044 panic("vget: vn_lock failed to return ENOENT\n");
2045 if (oweinact) {
2046 if (vp->v_iflag & VI_OWEINACT)
2047 vinactive(vp, td);
2048 VI_UNLOCK(vp);
2049 if ((oldflags & LK_TYPE_MASK) == 0)
2050 VOP_UNLOCK(vp, 0, td);
2051 } else
2052 VI_UNLOCK(vp);
2053 return (0);
2054}
2055
2056/*
2057 * Increase the reference count of a vnode.
2058 */
2059void
2060vref(struct vnode *vp)
2061{
2062
2063 VI_LOCK(vp);
2064 v_incr_usecount(vp);
2065 VI_UNLOCK(vp);
2066}
2067
2068/*
2069 * Return reference count of a vnode.
2070 *
2071 * The results of this call are only guaranteed when some mechanism other
2072 * than the VI lock is used to stop other processes from gaining references
2073 * to the vnode. This may be the case if the caller holds the only reference.
2074 * This is also useful when stale data is acceptable as race conditions may
2075 * be accounted for by some other means.
2076 */
2077int
2078vrefcnt(struct vnode *vp)
2079{
2080 int usecnt;
2081
2082 VI_LOCK(vp);
2083 usecnt = vp->v_usecount;
2084 VI_UNLOCK(vp);
2085
2086 return (usecnt);
2087}
2088
2089
2090/*
2091 * Vnode put/release.
2092 * If count drops to zero, call inactive routine and return to freelist.
2093 */
2094void
2095vrele(struct vnode *vp)
2096{
2097 struct thread *td = curthread; /* XXX */
2098
2099 KASSERT(vp != NULL, ("vrele: null vp"));
2100 VFS_ASSERT_GIANT(vp->v_mount);
2101
2102 VI_LOCK(vp);
2103
2104 /* Skip this v_writecount check if we're going to panic below. */
2105 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2106 ("vrele: missed vn_close"));
2107
2108 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2109 vp->v_usecount == 1)) {
2110 v_decr_usecount(vp);
2111 return;
2112 }
2113 if (vp->v_usecount != 1) {
2114#ifdef DIAGNOSTIC
2115 vprint("vrele: negative ref count", vp);
2116#endif
2117 VI_UNLOCK(vp);
2118 panic("vrele: negative ref cnt");
2119 }
2120 /*
2121 * We want to hold the vnode until the inactive finishes to
2122 * prevent vgone() races. We drop the use count here and the
2123 * hold count below when we're done.
2124 */
2125 v_decr_useonly(vp);
2126 /*
2127 * We must call VOP_INACTIVE with the node locked. Mark
2128 * as VI_DOINGINACT to avoid recursion.
2129 */
2130 vp->v_iflag |= VI_OWEINACT;
2131 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) {
2132 VI_LOCK(vp);
2133 if (vp->v_usecount > 0)
2134 vp->v_iflag &= ~VI_OWEINACT;
2135 if (vp->v_iflag & VI_OWEINACT)
2136 vinactive(vp, td);
2137 VOP_UNLOCK(vp, 0, td);
2138 } else {
2139 VI_LOCK(vp);
2140 if (vp->v_usecount > 0)
2141 vp->v_iflag &= ~VI_OWEINACT;
2142 }
2143 vdropl(vp);
2144}
2145
2146/*
2147 * Release an already locked vnode. This give the same effects as
2148 * unlock+vrele(), but takes less time and avoids releasing and
2149 * re-aquiring the lock (as vrele() aquires the lock internally.)
2150 */
2151void
2152vput(struct vnode *vp)
2153{
2154 struct thread *td = curthread; /* XXX */
2155 int error;
2156
2157 KASSERT(vp != NULL, ("vput: null vp"));
2158 ASSERT_VOP_LOCKED(vp, "vput");
2159 VFS_ASSERT_GIANT(vp->v_mount);
2160 VI_LOCK(vp);
2161 /* Skip this v_writecount check if we're going to panic below. */
2162 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2163 ("vput: missed vn_close"));
2164 error = 0;
2165
2166 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2167 vp->v_usecount == 1)) {
2168 VOP_UNLOCK(vp, 0, td);
2169 v_decr_usecount(vp);
2170 return;
2171 }
2172
2173 if (vp->v_usecount != 1) {
2174#ifdef DIAGNOSTIC
2175 vprint("vput: negative ref count", vp);
2176#endif
2177 panic("vput: negative ref cnt");
2178 }
2179 /*
2180 * We want to hold the vnode until the inactive finishes to
2181 * prevent vgone() races. We drop the use count here and the
2182 * hold count below when we're done.
2183 */
2184 v_decr_useonly(vp);
2185 vp->v_iflag |= VI_OWEINACT;
2186 if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) {
2187 error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td);
2188 VI_LOCK(vp);
2189 if (error) {
2190 if (vp->v_usecount > 0)
2191 vp->v_iflag &= ~VI_OWEINACT;
2192 goto done;
2193 }
2194 }
2195 if (vp->v_usecount > 0)
2196 vp->v_iflag &= ~VI_OWEINACT;
2197 if (vp->v_iflag & VI_OWEINACT)
2198 vinactive(vp, td);
2199 VOP_UNLOCK(vp, 0, td);
2200done:
2201 vdropl(vp);
2202}
2203
2204/*
2205 * Somebody doesn't want the vnode recycled.
2206 */
2207void
2208vhold(struct vnode *vp)
2209{
2210
2211 VI_LOCK(vp);
2212 vholdl(vp);
2213 VI_UNLOCK(vp);
2214}
2215
2216void
2217vholdl(struct vnode *vp)
2218{
2219
2220 vp->v_holdcnt++;
2221 if (VSHOULDBUSY(vp))
2222 vbusy(vp);
2223}
2224
2225/*
2226 * Note that there is one less who cares about this vnode. vdrop() is the
2227 * opposite of vhold().
2228 */
2229void
2230vdrop(struct vnode *vp)
2231{
2232
2233 VI_LOCK(vp);
2234 vdropl(vp);
2235}
2236
2237/*
2238 * Drop the hold count of the vnode. If this is the last reference to
2239 * the vnode we will free it if it has been vgone'd otherwise it is
2240 * placed on the free list.
2241 */
2242void
2243vdropl(struct vnode *vp)
2244{
2245
2246 ASSERT_VI_LOCKED(vp, "vdropl");
2247 if (vp->v_holdcnt <= 0)
2248 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2249 vp->v_holdcnt--;
2250 if (vp->v_holdcnt == 0) {
2251 if (vp->v_iflag & VI_DOOMED) {
2252 vdestroy(vp);
2253 return;
2254 } else
2255 vfree(vp);
2256 }
2257 VI_UNLOCK(vp);
2258}
2259
2260/*
2261 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2262 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2263 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2264 * failed lock upgrade.
2265 */
2266static void
2267vinactive(struct vnode *vp, struct thread *td)
2268{
2269
2270 ASSERT_VOP_LOCKED(vp, "vinactive");
2271 ASSERT_VI_LOCKED(vp, "vinactive");
2272 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2273 ("vinactive: recursed on VI_DOINGINACT"));
2274 vp->v_iflag |= VI_DOINGINACT;
2275 vp->v_iflag &= ~VI_OWEINACT;
2276 VI_UNLOCK(vp);
2277 VOP_INACTIVE(vp, td);
2278 VI_LOCK(vp);
2279 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2280 ("vinactive: lost VI_DOINGINACT"));
2281 vp->v_iflag &= ~VI_DOINGINACT;
2282}
2283
2284/*
2285 * Remove any vnodes in the vnode table belonging to mount point mp.
2286 *
2287 * If FORCECLOSE is not specified, there should not be any active ones,
2288 * return error if any are found (nb: this is a user error, not a
2289 * system error). If FORCECLOSE is specified, detach any active vnodes
2290 * that are found.
2291 *
2292 * If WRITECLOSE is set, only flush out regular file vnodes open for
2293 * writing.
2294 *
2295 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2296 *
2297 * `rootrefs' specifies the base reference count for the root vnode
2298 * of this filesystem. The root vnode is considered busy if its
2299 * v_usecount exceeds this value. On a successful return, vflush(, td)
2300 * will call vrele() on the root vnode exactly rootrefs times.
2301 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2302 * be zero.
2303 */
2304#ifdef DIAGNOSTIC
2305static int busyprt = 0; /* print out busy vnodes */
2306SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
2307#endif
2308
2309int
2310vflush( struct mount *mp, int rootrefs, int flags, struct thread *td)
2311{
2312 struct vnode *vp, *mvp, *rootvp = NULL;
2313 struct vattr vattr;
2314 int busy = 0, error;
2315
2316 CTR1(KTR_VFS, "vflush: mp %p", mp);
2317 if (rootrefs > 0) {
2318 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2319 ("vflush: bad args"));
2320 /*
2321 * Get the filesystem root vnode. We can vput() it
2322 * immediately, since with rootrefs > 0, it won't go away.
2323 */
2324 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp, td)) != 0)
2325 return (error);
2326 vput(rootvp);
2327
2328 }
2329 MNT_ILOCK(mp);
2330loop:
2331 MNT_VNODE_FOREACH(vp, mp, mvp) {
2332
2333 VI_LOCK(vp);
2334 vholdl(vp);
2335 MNT_IUNLOCK(mp);
2336 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td);
2337 if (error) {
2338 vdrop(vp);
2339 MNT_ILOCK(mp);
2340 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
2341 goto loop;
2342 }
2343 /*
2344 * Skip over a vnodes marked VV_SYSTEM.
2345 */
2346 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2347 VOP_UNLOCK(vp, 0, td);
2348 vdrop(vp);
2349 MNT_ILOCK(mp);
2350 continue;
2351 }
2352 /*
2353 * If WRITECLOSE is set, flush out unlinked but still open
2354 * files (even if open only for reading) and regular file
2355 * vnodes open for writing.
2356 */
2357 if (flags & WRITECLOSE) {
2358 error = VOP_GETATTR(vp, &vattr, td->td_ucred, td);
2359 VI_LOCK(vp);
2360
2361 if ((vp->v_type == VNON ||
2362 (error == 0 && vattr.va_nlink > 0)) &&
2363 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2364 VOP_UNLOCK(vp, 0, td);
2365 vdropl(vp);
2366 MNT_ILOCK(mp);
2367 continue;
2368 }
2369 } else
2370 VI_LOCK(vp);
2371 /*
2372 * With v_usecount == 0, all we need to do is clear out the
2373 * vnode data structures and we are done.
2374 *
2375 * If FORCECLOSE is set, forcibly close the vnode.
2376 */
2377 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2378 VNASSERT(vp->v_usecount == 0 ||
2379 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2380 ("device VNODE %p is FORCECLOSED", vp));
2381 vgonel(vp);
2382 } else {
2383 busy++;
2384#ifdef DIAGNOSTIC
2385 if (busyprt)
2386 vprint("vflush: busy vnode", vp);
2387#endif
2388 }
2389 VOP_UNLOCK(vp, 0, td);
2390 vdropl(vp);
2391 MNT_ILOCK(mp);
2392 }
2393 MNT_IUNLOCK(mp);
2394 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2395 /*
2396 * If just the root vnode is busy, and if its refcount
2397 * is equal to `rootrefs', then go ahead and kill it.
2398 */
2399 VI_LOCK(rootvp);
2400 KASSERT(busy > 0, ("vflush: not busy"));
2401 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2402 ("vflush: usecount %d < rootrefs %d",
2403 rootvp->v_usecount, rootrefs));
2404 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2405 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td);
2406 vgone(rootvp);
2407 VOP_UNLOCK(rootvp, 0, td);
2408 busy = 0;
2409 } else
2410 VI_UNLOCK(rootvp);
2411 }
2412 if (busy)
2413 return (EBUSY);
2414 for (; rootrefs > 0; rootrefs--)
2415 vrele(rootvp);
2416 return (0);
2417}
2418
2419/*
2420 * Recycle an unused vnode to the front of the free list.
2421 */
2422int
2423vrecycle(struct vnode *vp, struct thread *td)
2424{
2425 int recycled;
2426
2427 ASSERT_VOP_LOCKED(vp, "vrecycle");
2428 recycled = 0;
2429 VI_LOCK(vp);
2430 if (vp->v_usecount == 0) {
2431 recycled = 1;
2432 vgonel(vp);
2433 }
2434 VI_UNLOCK(vp);
2435 return (recycled);
2436}
2437
2438/*
2439 * Eliminate all activity associated with a vnode
2440 * in preparation for reuse.
2441 */
2442void
2443vgone(struct vnode *vp)
2444{
2445 VI_LOCK(vp);
2446 vgonel(vp);
2447 VI_UNLOCK(vp);
2448}
2449
2450/*
2451 * vgone, with the vp interlock held.
2452 */
2453void
2454vgonel(struct vnode *vp)
2455{
2456 struct thread *td;
2457 int oweinact;
2458 int active;
2459 struct mount *mp;
2460
2461 CTR1(KTR_VFS, "vgonel: vp %p", vp);
2462 ASSERT_VOP_LOCKED(vp, "vgonel");
2463 ASSERT_VI_LOCKED(vp, "vgonel");
2464 VNASSERT(vp->v_holdcnt, vp,
2465 ("vgonel: vp %p has no reference.", vp));
2466 td = curthread;
2467
2468 /*
2469 * Don't vgonel if we're already doomed.
2470 */
2471 if (vp->v_iflag & VI_DOOMED)
2472 return;
2473 vp->v_iflag |= VI_DOOMED;
2474 /*
2475 * Check to see if the vnode is in use. If so, we have to call
2476 * VOP_CLOSE() and VOP_INACTIVE().
2477 */
2478 active = vp->v_usecount;
2479 oweinact = (vp->v_iflag & VI_OWEINACT);
2480 VI_UNLOCK(vp);
2481 /*
2482 * Clean out any buffers associated with the vnode.
2483 * If the flush fails, just toss the buffers.
2484 */
2485 mp = NULL;
2486 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2487 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2488 if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0)
2489 vinvalbuf(vp, 0, td, 0, 0);
2490
2491 /*
2492 * If purging an active vnode, it must be closed and
2493 * deactivated before being reclaimed.
2494 */
2495 if (active)
2496 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2497 if (oweinact || active) {
2498 VI_LOCK(vp);
2499 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2500 vinactive(vp, td);
2501 VI_UNLOCK(vp);
2502 }
2503 /*
2504 * Reclaim the vnode.
2505 */
2506 if (VOP_RECLAIM(vp, td))
2507 panic("vgone: cannot reclaim");
2508 if (mp != NULL)
2509 vn_finished_secondary_write(mp);
2510 VNASSERT(vp->v_object == NULL, vp,
2511 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2512 /*
2513 * Delete from old mount point vnode list.
2514 */
2515 delmntque(vp);
2516 cache_purge(vp);
2517 /*
2518 * Done with purge, reset to the standard lock and invalidate
2519 * the vnode.
2520 */
2521 VI_LOCK(vp);
2522 vp->v_vnlock = &vp->v_lock;
2523 vp->v_op = &dead_vnodeops;
2524 vp->v_tag = "none";
2525 vp->v_type = VBAD;
2526}
2527
2528/*
2529 * Calculate the total number of references to a special device.
2530 */
2531int
2532vcount(struct vnode *vp)
2533{
2534 int count;
2535
2536 dev_lock();
2537 count = vp->v_rdev->si_usecount;
2538 dev_unlock();
2539 return (count);
2540}
2541
2542/*
2543 * Same as above, but using the struct cdev *as argument
2544 */
2545int
2546count_dev(struct cdev *dev)
2547{
2548 int count;
2549
2550 dev_lock();
2551 count = dev->si_usecount;
2552 dev_unlock();
2553 return(count);
2554}
2555
2556/*
2557 * Print out a description of a vnode.
2558 */
2559static char *typename[] =
2560{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2561 "VMARKER"};
2562
2563void
2564vn_printf(struct vnode *vp, const char *fmt, ...)
2565{
2566 va_list ap;
2567 char buf[96];
2568
2569 va_start(ap, fmt);
2570 vprintf(fmt, ap);
2571 va_end(ap);
2572 printf("%p: ", (void *)vp);
2573 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2574 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2575 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2576 buf[0] = '\0';
2577 buf[1] = '\0';
2578 if (vp->v_vflag & VV_ROOT)
2579 strcat(buf, "|VV_ROOT");
2580 if (vp->v_vflag & VV_TEXT)
2581 strcat(buf, "|VV_TEXT");
2582 if (vp->v_vflag & VV_SYSTEM)
2583 strcat(buf, "|VV_SYSTEM");
2584 if (vp->v_vflag & VV_DELETED)
2585 strcat(buf, "|VV_DELETED");
2586 if (vp->v_iflag & VI_DOOMED)
2587 strcat(buf, "|VI_DOOMED");
2588 if (vp->v_iflag & VI_FREE)
2589 strcat(buf, "|VI_FREE");
2590 printf(" flags (%s)\n", buf + 1);
2591 if (mtx_owned(VI_MTX(vp)))
2592 printf(" VI_LOCKed");
2593 if (vp->v_object != NULL)
2594 printf(" v_object %p ref %d pages %d\n",
2595 vp->v_object, vp->v_object->ref_count,
2596 vp->v_object->resident_page_count);
2597 printf(" ");
2598 lockmgr_printinfo(vp->v_vnlock);
2599 printf("\n");
2600 if (vp->v_data != NULL)
2601 VOP_PRINT(vp);
2602}
2603
2604#ifdef DDB
2605/*
2606 * List all of the locked vnodes in the system.
2607 * Called when debugging the kernel.
2608 */
2609DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2610{
2611 struct mount *mp, *nmp;
2612 struct vnode *vp;
2613
2614 /*
2615 * Note: because this is DDB, we can't obey the locking semantics
2616 * for these structures, which means we could catch an inconsistent
2617 * state and dereference a nasty pointer. Not much to be done
2618 * about that.
2619 */
2620 printf("Locked vnodes\n");
2621 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2622 nmp = TAILQ_NEXT(mp, mnt_list);
2623 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2624 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp, NULL))
2625 vprint("", vp);
2626 }
2627 nmp = TAILQ_NEXT(mp, mnt_list);
2628 }
2629}
2630
2631/*
2632 * Show details about the given vnode.
2633 */
2634DB_SHOW_COMMAND(vnode, db_show_vnode)
2635{
2636 struct vnode *vp;
2637
2638 if (!have_addr)
2639 return;
2640 vp = (struct vnode *)addr;
2641 vn_printf(vp, "vnode ");
2642}
2643#endif /* DDB */
2644
2645/*
2646 * Fill in a struct xvfsconf based on a struct vfsconf.
2647 */
2648static void
2649vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
2650{
2651
2652 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
2653 xvfsp->vfc_typenum = vfsp->vfc_typenum;
2654 xvfsp->vfc_refcount = vfsp->vfc_refcount;
2655 xvfsp->vfc_flags = vfsp->vfc_flags;
2656 /*
2657 * These are unused in userland, we keep them
2658 * to not break binary compatibility.
2659 */
2660 xvfsp->vfc_vfsops = NULL;
2661 xvfsp->vfc_next = NULL;
2662}
2663
2664/*
2665 * Top level filesystem related information gathering.
2666 */
2667static int
2668sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
2669{
2670 struct vfsconf *vfsp;
2671 struct xvfsconf xvfsp;
2672 int error;
2673
2674 error = 0;
2675 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2676 bzero(&xvfsp, sizeof(xvfsp));
2677 vfsconf2x(vfsp, &xvfsp);
2678 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
2679 if (error)
2680 break;
2681 }
2682 return (error);
2683}
2684
2685SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist,
2686 "S,xvfsconf", "List of all configured filesystems");
2687
2688#ifndef BURN_BRIDGES
2689static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
2690
2691static int
2692vfs_sysctl(SYSCTL_HANDLER_ARGS)
2693{
2694 int *name = (int *)arg1 - 1; /* XXX */
2695 u_int namelen = arg2 + 1; /* XXX */
2696 struct vfsconf *vfsp;
2697 struct xvfsconf xvfsp;
2698
2699 printf("WARNING: userland calling deprecated sysctl, "
2700 "please rebuild world\n");
2701
2702#if 1 || defined(COMPAT_PRELITE2)
2703 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
2704 if (namelen == 1)
2705 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
2706#endif
2707
2708 switch (name[1]) {
2709 case VFS_MAXTYPENUM:
2710 if (namelen != 2)
2711 return (ENOTDIR);
2712 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
2713 case VFS_CONF:
2714 if (namelen != 3)
2715 return (ENOTDIR); /* overloaded */
2716 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
2717 if (vfsp->vfc_typenum == name[2])
2718 break;
2719 if (vfsp == NULL)
2720 return (EOPNOTSUPP);
2721 bzero(&xvfsp, sizeof(xvfsp));
2722 vfsconf2x(vfsp, &xvfsp);
2723 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
2724 }
2725 return (EOPNOTSUPP);
2726}
2727
2728static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
2729 vfs_sysctl, "Generic filesystem");
2730
2731#if 1 || defined(COMPAT_PRELITE2)
2732
2733static int
2734sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
2735{
2736 int error;
2737 struct vfsconf *vfsp;
2738 struct ovfsconf ovfs;
2739
2740 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
2741 bzero(&ovfs, sizeof(ovfs));
2742 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
2743 strcpy(ovfs.vfc_name, vfsp->vfc_name);
2744 ovfs.vfc_index = vfsp->vfc_typenum;
2745 ovfs.vfc_refcount = vfsp->vfc_refcount;
2746 ovfs.vfc_flags = vfsp->vfc_flags;
2747 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
2748 if (error)
2749 return error;
2750 }
2751 return 0;
2752}
2753
2754#endif /* 1 || COMPAT_PRELITE2 */
2755#endif /* !BURN_BRIDGES */
2756
2757#define KINFO_VNODESLOP 10
2758#ifdef notyet
2759/*
2760 * Dump vnode list (via sysctl).
2761 */
2762/* ARGSUSED */
2763static int
2764sysctl_vnode(SYSCTL_HANDLER_ARGS)
2765{
2766 struct xvnode *xvn;
2767 struct thread *td = req->td;
2768 struct mount *mp;
2769 struct vnode *vp;
2770 int error, len, n;
2771
2772 /*
2773 * Stale numvnodes access is not fatal here.
2774 */
2775 req->lock = 0;
2776 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
2777 if (!req->oldptr)
2778 /* Make an estimate */
2779 return (SYSCTL_OUT(req, 0, len));
2780
2781 error = sysctl_wire_old_buffer(req, 0);
2782 if (error != 0)
2783 return (error);
2784 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
2785 n = 0;
2786 mtx_lock(&mountlist_mtx);
2787 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2788 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td))
2789 continue;
2790 MNT_ILOCK(mp);
2791 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2792 if (n == len)
2793 break;
2794 vref(vp);
2795 xvn[n].xv_size = sizeof *xvn;
2796 xvn[n].xv_vnode = vp;
2797 xvn[n].xv_id = 0; /* XXX compat */
2798#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
2799 XV_COPY(usecount);
2800 XV_COPY(writecount);
2801 XV_COPY(holdcnt);
2802 XV_COPY(mount);
2803 XV_COPY(numoutput);
2804 XV_COPY(type);
2805#undef XV_COPY
2806 xvn[n].xv_flag = vp->v_vflag;
2807
2808 switch (vp->v_type) {
2809 case VREG:
2810 case VDIR:
2811 case VLNK:
2812 break;
2813 case VBLK:
2814 case VCHR:
2815 if (vp->v_rdev == NULL) {
2816 vrele(vp);
2817 continue;
2818 }
2819 xvn[n].xv_dev = dev2udev(vp->v_rdev);
2820 break;
2821 case VSOCK:
2822 xvn[n].xv_socket = vp->v_socket;
2823 break;
2824 case VFIFO:
2825 xvn[n].xv_fifo = vp->v_fifoinfo;
2826 break;
2827 case VNON:
2828 case VBAD:
2829 default:
2830 /* shouldn't happen? */
2831 vrele(vp);
2832 continue;
2833 }
2834 vrele(vp);
2835 ++n;
2836 }
2837 MNT_IUNLOCK(mp);
2838 mtx_lock(&mountlist_mtx);
2839 vfs_unbusy(mp, td);
2840 if (n == len)
2841 break;
2842 }
2843 mtx_unlock(&mountlist_mtx);
2844
2845 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
2846 free(xvn, M_TEMP);
2847 return (error);
2848}
2849
2850SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
2851 0, 0, sysctl_vnode, "S,xvnode", "");
2852#endif
2853
2854/*
2855 * Unmount all filesystems. The list is traversed in reverse order
2856 * of mounting to avoid dependencies.
2857 */
2858void
2859vfs_unmountall(void)
2860{
2861 struct mount *mp;
2862 struct thread *td;
2863 int error;
2864
2865 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
2866 td = curthread;
2867 /*
2868 * Since this only runs when rebooting, it is not interlocked.
2869 */
2870 while(!TAILQ_EMPTY(&mountlist)) {
2871 mp = TAILQ_LAST(&mountlist, mntlist);
2872 error = dounmount(mp, MNT_FORCE, td);
2873 if (error) {
2874 TAILQ_REMOVE(&mountlist, mp, mnt_list);
2875 /*
2876 * XXX: Due to the way in which we mount the root
2877 * file system off of devfs, devfs will generate a
2878 * "busy" warning when we try to unmount it before
2879 * the root. Don't print a warning as a result in
2880 * order to avoid false positive errors that may
2881 * cause needless upset.
2882 */
2883 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
2884 printf("unmount of %s failed (",
2885 mp->mnt_stat.f_mntonname);
2886 if (error == EBUSY)
2887 printf("BUSY)\n");
2888 else
2889 printf("%d)\n", error);
2890 }
2891 } else {
2892 /* The unmount has removed mp from the mountlist */
2893 }
2894 }
2895}
2896
2897/*
2898 * perform msync on all vnodes under a mount point
2899 * the mount point must be locked.
2900 */
2901void
2902vfs_msync(struct mount *mp, int flags)
2903{
2904 struct vnode *vp, *mvp;
2905 struct vm_object *obj;
2906
2907 MNT_ILOCK(mp);
2908 MNT_VNODE_FOREACH(vp, mp, mvp) {
2909 VI_LOCK(vp);
2910 if ((vp->v_iflag & VI_OBJDIRTY) &&
2911 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
2912 MNT_IUNLOCK(mp);
2913 if (!vget(vp,
2914 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
2915 curthread)) {
2916 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
2917 vput(vp);
2918 MNT_ILOCK(mp);
2919 continue;
2920 }
2921
2922 obj = vp->v_object;
2923 if (obj != NULL) {
2924 VM_OBJECT_LOCK(obj);
2925 vm_object_page_clean(obj, 0, 0,
2926 flags == MNT_WAIT ?
2927 OBJPC_SYNC : OBJPC_NOSYNC);
2928 VM_OBJECT_UNLOCK(obj);
2929 }
2930 vput(vp);
2931 }
2932 MNT_ILOCK(mp);
2933 } else
2934 VI_UNLOCK(vp);
2935 }
2936 MNT_IUNLOCK(mp);
2937}
2938
2939/*
2940 * Mark a vnode as free, putting it up for recycling.
2941 */
2942static void
2943vfree(struct vnode *vp)
2944{
2945
2946 CTR1(KTR_VFS, "vfree vp %p", vp);
2947 ASSERT_VI_LOCKED(vp, "vfree");
2948 mtx_lock(&vnode_free_list_mtx);
2949 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed."));
2950 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free"));
2951 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't"));
2952 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp,
2953 ("vfree: Freeing doomed vnode"));
2954 if (vp->v_iflag & VI_AGE) {
2955 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
2956 } else {
2957 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
2958 }
2959 freevnodes++;
2960 vp->v_iflag &= ~VI_AGE;
2961 vp->v_iflag |= VI_FREE;
2962 mtx_unlock(&vnode_free_list_mtx);
2963}
2964
2965/*
2966 * Opposite of vfree() - mark a vnode as in use.
2967 */
2968static void
2969vbusy(struct vnode *vp)
2970{
2971 CTR1(KTR_VFS, "vbusy vp %p", vp);
2972 ASSERT_VI_LOCKED(vp, "vbusy");
2973 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
2974 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed."));
2975
2976 mtx_lock(&vnode_free_list_mtx);
2977 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
2978 freevnodes--;
2979 vp->v_iflag &= ~(VI_FREE|VI_AGE);
2980 mtx_unlock(&vnode_free_list_mtx);
2981}
2982
2983/*
2984 * Initalize per-vnode helper structure to hold poll-related state.
2985 */
2986void
2987v_addpollinfo(struct vnode *vp)
2988{
2989 struct vpollinfo *vi;
2990
2991 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
2992 if (vp->v_pollinfo != NULL) {
2993 uma_zfree(vnodepoll_zone, vi);
2994 return;
2995 }
2996 vp->v_pollinfo = vi;
2997 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
2998 knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock,
2999 vfs_knlunlock, vfs_knllocked);
3000}
3001
3002/*
3003 * Record a process's interest in events which might happen to
3004 * a vnode. Because poll uses the historic select-style interface
3005 * internally, this routine serves as both the ``check for any
3006 * pending events'' and the ``record my interest in future events''
3007 * functions. (These are done together, while the lock is held,
3008 * to avoid race conditions.)
3009 */
3010int
3011vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3012{
3013
3014 if (vp->v_pollinfo == NULL)
3015 v_addpollinfo(vp);
3016 mtx_lock(&vp->v_pollinfo->vpi_lock);
3017 if (vp->v_pollinfo->vpi_revents & events) {
3018 /*
3019 * This leaves events we are not interested
3020 * in available for the other process which
3021 * which presumably had requested them
3022 * (otherwise they would never have been
3023 * recorded).
3024 */
3025 events &= vp->v_pollinfo->vpi_revents;
3026 vp->v_pollinfo->vpi_revents &= ~events;
3027
3028 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3029 return events;
3030 }
3031 vp->v_pollinfo->vpi_events |= events;
3032 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3033 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3034 return 0;
3035}
3036
3037/*
3038 * Routine to create and manage a filesystem syncer vnode.
3039 */
3040#define sync_close ((int (*)(struct vop_close_args *))nullop)
3041static int sync_fsync(struct vop_fsync_args *);
3042static int sync_inactive(struct vop_inactive_args *);
3043static int sync_reclaim(struct vop_reclaim_args *);
3044
3045static struct vop_vector sync_vnodeops = {
3046 .vop_bypass = VOP_EOPNOTSUPP,
3047 .vop_close = sync_close, /* close */
3048 .vop_fsync = sync_fsync, /* fsync */
3049 .vop_inactive = sync_inactive, /* inactive */
3050 .vop_reclaim = sync_reclaim, /* reclaim */
|