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