FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_subr.c
1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
35 */
36
37 /*
38 * External virtual filesystem routines
39 */
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: releng/9.1/sys/kern/vfs_subr.c 237839 2012-06-30 14:17:59Z avg $");
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 #include <sys/watchdog.h>
77
78 #include <machine/stdarg.h>
79
80 #include <security/mac/mac_framework.h>
81
82 #include <vm/vm.h>
83 #include <vm/vm_object.h>
84 #include <vm/vm_extern.h>
85 #include <vm/pmap.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_page.h>
88 #include <vm/vm_kern.h>
89 #include <vm/uma.h>
90
91 #ifdef DDB
92 #include <ddb/ddb.h>
93 #endif
94
95 #define WI_MPSAFEQ 0
96 #define WI_GIANTQ 1
97
98 static void delmntque(struct vnode *vp);
99 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
100 int slpflag, int slptimeo);
101 static void syncer_shutdown(void *arg, int howto);
102 static int vtryrecycle(struct vnode *vp);
103 static void v_incr_usecount(struct vnode *);
104 static void v_decr_usecount(struct vnode *);
105 static void v_decr_useonly(struct vnode *);
106 static void v_upgrade_usecount(struct vnode *);
107 static void vnlru_free(int);
108 static void vgonel(struct vnode *);
109 static void vfs_knllock(void *arg);
110 static void vfs_knlunlock(void *arg);
111 static void vfs_knl_assert_locked(void *arg);
112 static void vfs_knl_assert_unlocked(void *arg);
113 static void destroy_vpollinfo(struct vpollinfo *vi);
114
115 /*
116 * Number of vnodes in existence. Increased whenever getnewvnode()
117 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
118 */
119 static unsigned long numvnodes;
120
121 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
122 "Number of vnodes in existence");
123
124 /*
125 * Conversion tables for conversion from vnode types to inode formats
126 * and back.
127 */
128 enum vtype iftovt_tab[16] = {
129 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
130 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
131 };
132 int vttoif_tab[10] = {
133 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
134 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
135 };
136
137 /*
138 * List of vnodes that are ready for recycling.
139 */
140 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
141
142 /*
143 * Free vnode target. Free vnodes may simply be files which have been stat'd
144 * but not read. This is somewhat common, and a small cache of such files
145 * should be kept to avoid recreation costs.
146 */
147 static u_long wantfreevnodes;
148 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
149 /* Number of vnodes in the free list. */
150 static u_long freevnodes;
151 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0,
152 "Number of vnodes in the free list");
153
154 static int vlru_allow_cache_src;
155 SYSCTL_INT(_vfs, OID_AUTO, vlru_allow_cache_src, CTLFLAG_RW,
156 &vlru_allow_cache_src, 0, "Allow vlru to reclaim source vnode");
157
158 /*
159 * Various variables used for debugging the new implementation of
160 * reassignbuf().
161 * XXX these are probably of (very) limited utility now.
162 */
163 static int reassignbufcalls;
164 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
165 "Number of calls to reassignbuf");
166
167 /*
168 * Cache for the mount type id assigned to NFS. This is used for
169 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
170 */
171 int nfs_mount_type = -1;
172
173 /* To keep more than one thread at a time from running vfs_getnewfsid */
174 static struct mtx mntid_mtx;
175
176 /*
177 * Lock for any access to the following:
178 * vnode_free_list
179 * numvnodes
180 * freevnodes
181 */
182 static struct mtx vnode_free_list_mtx;
183
184 /* Publicly exported FS */
185 struct nfs_public nfs_pub;
186
187 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
188 static uma_zone_t vnode_zone;
189 static uma_zone_t vnodepoll_zone;
190
191 /*
192 * The workitem queue.
193 *
194 * It is useful to delay writes of file data and filesystem metadata
195 * for tens of seconds so that quickly created and deleted files need
196 * not waste disk bandwidth being created and removed. To realize this,
197 * we append vnodes to a "workitem" queue. When running with a soft
198 * updates implementation, most pending metadata dependencies should
199 * not wait for more than a few seconds. Thus, mounted on block devices
200 * are delayed only about a half the time that file data is delayed.
201 * Similarly, directory updates are more critical, so are only delayed
202 * about a third the time that file data is delayed. Thus, there are
203 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
204 * one each second (driven off the filesystem syncer process). The
205 * syncer_delayno variable indicates the next queue that is to be processed.
206 * Items that need to be processed soon are placed in this queue:
207 *
208 * syncer_workitem_pending[syncer_delayno]
209 *
210 * A delay of fifteen seconds is done by placing the request fifteen
211 * entries later in the queue:
212 *
213 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
214 *
215 */
216 static int syncer_delayno;
217 static long syncer_mask;
218 LIST_HEAD(synclist, bufobj);
219 static struct synclist *syncer_workitem_pending[2];
220 /*
221 * The sync_mtx protects:
222 * bo->bo_synclist
223 * sync_vnode_count
224 * syncer_delayno
225 * syncer_state
226 * syncer_workitem_pending
227 * syncer_worklist_len
228 * rushjob
229 */
230 static struct mtx sync_mtx;
231 static struct cv sync_wakeup;
232
233 #define SYNCER_MAXDELAY 32
234 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
235 static int syncdelay = 30; /* max time to delay syncing data */
236 static int filedelay = 30; /* time to delay syncing files */
237 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
238 "Time to delay syncing files (in seconds)");
239 static int dirdelay = 29; /* time to delay syncing directories */
240 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
241 "Time to delay syncing directories (in seconds)");
242 static int metadelay = 28; /* time to delay syncing metadata */
243 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
244 "Time to delay syncing metadata (in seconds)");
245 static int rushjob; /* number of slots to run ASAP */
246 static int stat_rush_requests; /* number of times I/O speeded up */
247 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
248 "Number of times I/O speeded up (rush requests)");
249
250 /*
251 * When shutting down the syncer, run it at four times normal speed.
252 */
253 #define SYNCER_SHUTDOWN_SPEEDUP 4
254 static int sync_vnode_count;
255 static int syncer_worklist_len;
256 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
257 syncer_state;
258
259 /*
260 * Number of vnodes we want to exist at any one time. This is mostly used
261 * to size hash tables in vnode-related code. It is normally not used in
262 * getnewvnode(), as wantfreevnodes is normally nonzero.)
263 *
264 * XXX desiredvnodes is historical cruft and should not exist.
265 */
266 int desiredvnodes;
267 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
268 &desiredvnodes, 0, "Maximum number of vnodes");
269 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
270 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
271 static int vnlru_nowhere;
272 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
273 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
274
275 /*
276 * Macros to control when a vnode is freed and recycled. All require
277 * the vnode interlock.
278 */
279 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
280 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
281 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
282
283
284 /*
285 * Initialize the vnode management data structures.
286 *
287 * Reevaluate the following cap on the number of vnodes after the physical
288 * memory size exceeds 512GB. In the limit, as the physical memory size
289 * grows, the ratio of physical pages to vnodes approaches sixteen to one.
290 */
291 #ifndef MAXVNODES_MAX
292 #define MAXVNODES_MAX (512 * (1024 * 1024 * 1024 / (int)PAGE_SIZE / 16))
293 #endif
294 static void
295 vntblinit(void *dummy __unused)
296 {
297 int physvnodes, virtvnodes;
298
299 /*
300 * Desiredvnodes is a function of the physical memory size and the
301 * kernel's heap size. Generally speaking, it scales with the
302 * physical memory size. The ratio of desiredvnodes to physical pages
303 * is one to four until desiredvnodes exceeds 98,304. Thereafter, the
304 * marginal ratio of desiredvnodes to physical pages is one to
305 * sixteen. However, desiredvnodes is limited by the kernel's heap
306 * size. The memory required by desiredvnodes vnodes and vm objects
307 * may not exceed one seventh of the kernel's heap size.
308 */
309 physvnodes = maxproc + cnt.v_page_count / 16 + 3 * min(98304 * 4,
310 cnt.v_page_count) / 16;
311 virtvnodes = vm_kmem_size / (7 * (sizeof(struct vm_object) +
312 sizeof(struct vnode)));
313 desiredvnodes = min(physvnodes, virtvnodes);
314 if (desiredvnodes > MAXVNODES_MAX) {
315 if (bootverbose)
316 printf("Reducing kern.maxvnodes %d -> %d\n",
317 desiredvnodes, MAXVNODES_MAX);
318 desiredvnodes = MAXVNODES_MAX;
319 }
320 wantfreevnodes = desiredvnodes / 4;
321 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
322 TAILQ_INIT(&vnode_free_list);
323 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
324 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
325 NULL, NULL, UMA_ALIGN_PTR, 0);
326 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
327 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
328 /*
329 * Initialize the filesystem syncer.
330 */
331 syncer_workitem_pending[WI_MPSAFEQ] = hashinit(syncer_maxdelay, M_VNODE,
332 &syncer_mask);
333 syncer_workitem_pending[WI_GIANTQ] = hashinit(syncer_maxdelay, M_VNODE,
334 &syncer_mask);
335 syncer_maxdelay = syncer_mask + 1;
336 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
337 cv_init(&sync_wakeup, "syncer");
338 }
339 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
340
341
342 /*
343 * Mark a mount point as busy. Used to synchronize access and to delay
344 * unmounting. Eventually, mountlist_mtx is not released on failure.
345 *
346 * vfs_busy() is a custom lock, it can block the caller.
347 * vfs_busy() only sleeps if the unmount is active on the mount point.
348 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
349 * vnode belonging to mp.
350 *
351 * Lookup uses vfs_busy() to traverse mount points.
352 * root fs var fs
353 * / vnode lock A / vnode lock (/var) D
354 * /var vnode lock B /log vnode lock(/var/log) E
355 * vfs_busy lock C vfs_busy lock F
356 *
357 * Within each file system, the lock order is C->A->B and F->D->E.
358 *
359 * When traversing across mounts, the system follows that lock order:
360 *
361 * C->A->B
362 * |
363 * +->F->D->E
364 *
365 * The lookup() process for namei("/var") illustrates the process:
366 * VOP_LOOKUP() obtains B while A is held
367 * vfs_busy() obtains a shared lock on F while A and B are held
368 * vput() releases lock on B
369 * vput() releases lock on A
370 * VFS_ROOT() obtains lock on D while shared lock on F is held
371 * vfs_unbusy() releases shared lock on F
372 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
373 * Attempt to lock A (instead of vp_crossmp) while D is held would
374 * violate the global order, causing deadlocks.
375 *
376 * dounmount() locks B while F is drained.
377 */
378 int
379 vfs_busy(struct mount *mp, int flags)
380 {
381
382 MPASS((flags & ~MBF_MASK) == 0);
383 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
384
385 MNT_ILOCK(mp);
386 MNT_REF(mp);
387 /*
388 * If mount point is currenly being unmounted, sleep until the
389 * mount point fate is decided. If thread doing the unmounting fails,
390 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
391 * that this mount point has survived the unmount attempt and vfs_busy
392 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
393 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
394 * about to be really destroyed. vfs_busy needs to release its
395 * reference on the mount point in this case and return with ENOENT,
396 * telling the caller that mount mount it tried to busy is no longer
397 * valid.
398 */
399 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
400 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
401 MNT_REL(mp);
402 MNT_IUNLOCK(mp);
403 CTR1(KTR_VFS, "%s: failed busying before sleeping",
404 __func__);
405 return (ENOENT);
406 }
407 if (flags & MBF_MNTLSTLOCK)
408 mtx_unlock(&mountlist_mtx);
409 mp->mnt_kern_flag |= MNTK_MWAIT;
410 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
411 if (flags & MBF_MNTLSTLOCK)
412 mtx_lock(&mountlist_mtx);
413 MNT_ILOCK(mp);
414 }
415 if (flags & MBF_MNTLSTLOCK)
416 mtx_unlock(&mountlist_mtx);
417 mp->mnt_lockref++;
418 MNT_IUNLOCK(mp);
419 return (0);
420 }
421
422 /*
423 * Free a busy filesystem.
424 */
425 void
426 vfs_unbusy(struct mount *mp)
427 {
428
429 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
430 MNT_ILOCK(mp);
431 MNT_REL(mp);
432 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
433 mp->mnt_lockref--;
434 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
435 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
436 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
437 mp->mnt_kern_flag &= ~MNTK_DRAINING;
438 wakeup(&mp->mnt_lockref);
439 }
440 MNT_IUNLOCK(mp);
441 }
442
443 /*
444 * Lookup a mount point by filesystem identifier.
445 */
446 struct mount *
447 vfs_getvfs(fsid_t *fsid)
448 {
449 struct mount *mp;
450
451 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
452 mtx_lock(&mountlist_mtx);
453 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
454 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
455 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
456 vfs_ref(mp);
457 mtx_unlock(&mountlist_mtx);
458 return (mp);
459 }
460 }
461 mtx_unlock(&mountlist_mtx);
462 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
463 return ((struct mount *) 0);
464 }
465
466 /*
467 * Lookup a mount point by filesystem identifier, busying it before
468 * returning.
469 */
470 struct mount *
471 vfs_busyfs(fsid_t *fsid)
472 {
473 struct mount *mp;
474 int error;
475
476 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
477 mtx_lock(&mountlist_mtx);
478 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
479 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
480 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
481 error = vfs_busy(mp, MBF_MNTLSTLOCK);
482 if (error) {
483 mtx_unlock(&mountlist_mtx);
484 return (NULL);
485 }
486 return (mp);
487 }
488 }
489 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
490 mtx_unlock(&mountlist_mtx);
491 return ((struct mount *) 0);
492 }
493
494 /*
495 * Check if a user can access privileged mount options.
496 */
497 int
498 vfs_suser(struct mount *mp, struct thread *td)
499 {
500 int error;
501
502 /*
503 * If the thread is jailed, but this is not a jail-friendly file
504 * system, deny immediately.
505 */
506 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
507 return (EPERM);
508
509 /*
510 * If the file system was mounted outside the jail of the calling
511 * thread, deny immediately.
512 */
513 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
514 return (EPERM);
515
516 /*
517 * If file system supports delegated administration, we don't check
518 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
519 * by the file system itself.
520 * If this is not the user that did original mount, we check for
521 * the PRIV_VFS_MOUNT_OWNER privilege.
522 */
523 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
524 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
525 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
526 return (error);
527 }
528 return (0);
529 }
530
531 /*
532 * Get a new unique fsid. Try to make its val[0] unique, since this value
533 * will be used to create fake device numbers for stat(). Also try (but
534 * not so hard) make its val[0] unique mod 2^16, since some emulators only
535 * support 16-bit device numbers. We end up with unique val[0]'s for the
536 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
537 *
538 * Keep in mind that several mounts may be running in parallel. Starting
539 * the search one past where the previous search terminated is both a
540 * micro-optimization and a defense against returning the same fsid to
541 * different mounts.
542 */
543 void
544 vfs_getnewfsid(struct mount *mp)
545 {
546 static uint16_t mntid_base;
547 struct mount *nmp;
548 fsid_t tfsid;
549 int mtype;
550
551 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
552 mtx_lock(&mntid_mtx);
553 mtype = mp->mnt_vfc->vfc_typenum;
554 tfsid.val[1] = mtype;
555 mtype = (mtype & 0xFF) << 24;
556 for (;;) {
557 tfsid.val[0] = makedev(255,
558 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
559 mntid_base++;
560 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
561 break;
562 vfs_rel(nmp);
563 }
564 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
565 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
566 mtx_unlock(&mntid_mtx);
567 }
568
569 /*
570 * Knob to control the precision of file timestamps:
571 *
572 * 0 = seconds only; nanoseconds zeroed.
573 * 1 = seconds and nanoseconds, accurate within 1/HZ.
574 * 2 = seconds and nanoseconds, truncated to microseconds.
575 * >=3 = seconds and nanoseconds, maximum precision.
576 */
577 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
578
579 static int timestamp_precision = TSP_SEC;
580 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
581 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
582 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, "
583 "3+: sec + ns (max. precision))");
584
585 /*
586 * Get a current timestamp.
587 */
588 void
589 vfs_timestamp(struct timespec *tsp)
590 {
591 struct timeval tv;
592
593 switch (timestamp_precision) {
594 case TSP_SEC:
595 tsp->tv_sec = time_second;
596 tsp->tv_nsec = 0;
597 break;
598 case TSP_HZ:
599 getnanotime(tsp);
600 break;
601 case TSP_USEC:
602 microtime(&tv);
603 TIMEVAL_TO_TIMESPEC(&tv, tsp);
604 break;
605 case TSP_NSEC:
606 default:
607 nanotime(tsp);
608 break;
609 }
610 }
611
612 /*
613 * Set vnode attributes to VNOVAL
614 */
615 void
616 vattr_null(struct vattr *vap)
617 {
618
619 vap->va_type = VNON;
620 vap->va_size = VNOVAL;
621 vap->va_bytes = VNOVAL;
622 vap->va_mode = VNOVAL;
623 vap->va_nlink = VNOVAL;
624 vap->va_uid = VNOVAL;
625 vap->va_gid = VNOVAL;
626 vap->va_fsid = VNOVAL;
627 vap->va_fileid = VNOVAL;
628 vap->va_blocksize = VNOVAL;
629 vap->va_rdev = VNOVAL;
630 vap->va_atime.tv_sec = VNOVAL;
631 vap->va_atime.tv_nsec = VNOVAL;
632 vap->va_mtime.tv_sec = VNOVAL;
633 vap->va_mtime.tv_nsec = VNOVAL;
634 vap->va_ctime.tv_sec = VNOVAL;
635 vap->va_ctime.tv_nsec = VNOVAL;
636 vap->va_birthtime.tv_sec = VNOVAL;
637 vap->va_birthtime.tv_nsec = VNOVAL;
638 vap->va_flags = VNOVAL;
639 vap->va_gen = VNOVAL;
640 vap->va_vaflags = 0;
641 }
642
643 /*
644 * This routine is called when we have too many vnodes. It attempts
645 * to free <count> vnodes and will potentially free vnodes that still
646 * have VM backing store (VM backing store is typically the cause
647 * of a vnode blowout so we want to do this). Therefore, this operation
648 * is not considered cheap.
649 *
650 * A number of conditions may prevent a vnode from being reclaimed.
651 * the buffer cache may have references on the vnode, a directory
652 * vnode may still have references due to the namei cache representing
653 * underlying files, or the vnode may be in active use. It is not
654 * desireable to reuse such vnodes. These conditions may cause the
655 * number of vnodes to reach some minimum value regardless of what
656 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
657 */
658 static int
659 vlrureclaim(struct mount *mp)
660 {
661 struct vnode *vp;
662 int done;
663 int trigger;
664 int usevnodes;
665 int count;
666
667 /*
668 * Calculate the trigger point, don't allow user
669 * screwups to blow us up. This prevents us from
670 * recycling vnodes with lots of resident pages. We
671 * aren't trying to free memory, we are trying to
672 * free vnodes.
673 */
674 usevnodes = desiredvnodes;
675 if (usevnodes <= 0)
676 usevnodes = 1;
677 trigger = cnt.v_page_count * 2 / usevnodes;
678 done = 0;
679 vn_start_write(NULL, &mp, V_WAIT);
680 MNT_ILOCK(mp);
681 count = mp->mnt_nvnodelistsize / 10 + 1;
682 while (count != 0) {
683 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
684 while (vp != NULL && vp->v_type == VMARKER)
685 vp = TAILQ_NEXT(vp, v_nmntvnodes);
686 if (vp == NULL)
687 break;
688 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
689 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
690 --count;
691 if (!VI_TRYLOCK(vp))
692 goto next_iter;
693 /*
694 * If it's been deconstructed already, it's still
695 * referenced, or it exceeds the trigger, skip it.
696 */
697 if (vp->v_usecount ||
698 (!vlru_allow_cache_src &&
699 !LIST_EMPTY(&(vp)->v_cache_src)) ||
700 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
701 vp->v_object->resident_page_count > trigger)) {
702 VI_UNLOCK(vp);
703 goto next_iter;
704 }
705 MNT_IUNLOCK(mp);
706 vholdl(vp);
707 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
708 vdrop(vp);
709 goto next_iter_mntunlocked;
710 }
711 VI_LOCK(vp);
712 /*
713 * v_usecount may have been bumped after VOP_LOCK() dropped
714 * the vnode interlock and before it was locked again.
715 *
716 * It is not necessary to recheck VI_DOOMED because it can
717 * only be set by another thread that holds both the vnode
718 * lock and vnode interlock. If another thread has the
719 * vnode lock before we get to VOP_LOCK() and obtains the
720 * vnode interlock after VOP_LOCK() drops the vnode
721 * interlock, the other thread will be unable to drop the
722 * vnode lock before our VOP_LOCK() call fails.
723 */
724 if (vp->v_usecount ||
725 (!vlru_allow_cache_src &&
726 !LIST_EMPTY(&(vp)->v_cache_src)) ||
727 (vp->v_object != NULL &&
728 vp->v_object->resident_page_count > trigger)) {
729 VOP_UNLOCK(vp, LK_INTERLOCK);
730 goto next_iter_mntunlocked;
731 }
732 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
733 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
734 vgonel(vp);
735 VOP_UNLOCK(vp, 0);
736 vdropl(vp);
737 done++;
738 next_iter_mntunlocked:
739 if (!should_yield())
740 goto relock_mnt;
741 goto yield;
742 next_iter:
743 if (!should_yield())
744 continue;
745 MNT_IUNLOCK(mp);
746 yield:
747 kern_yield(PRI_UNCHANGED);
748 relock_mnt:
749 MNT_ILOCK(mp);
750 }
751 MNT_IUNLOCK(mp);
752 vn_finished_write(mp);
753 return done;
754 }
755
756 /*
757 * Attempt to keep the free list at wantfreevnodes length.
758 */
759 static void
760 vnlru_free(int count)
761 {
762 struct vnode *vp;
763 int vfslocked;
764
765 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
766 for (; count > 0; count--) {
767 vp = TAILQ_FIRST(&vnode_free_list);
768 /*
769 * The list can be modified while the free_list_mtx
770 * has been dropped and vp could be NULL here.
771 */
772 if (!vp)
773 break;
774 VNASSERT(vp->v_op != NULL, vp,
775 ("vnlru_free: vnode already reclaimed."));
776 KASSERT((vp->v_iflag & VI_FREE) != 0,
777 ("Removing vnode not on freelist"));
778 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
779 ("Mangling active vnode"));
780 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
781 /*
782 * Don't recycle if we can't get the interlock.
783 */
784 if (!VI_TRYLOCK(vp)) {
785 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
786 continue;
787 }
788 VNASSERT(VCANRECYCLE(vp), vp,
789 ("vp inconsistent on freelist"));
790 freevnodes--;
791 vp->v_iflag &= ~VI_FREE;
792 vholdl(vp);
793 mtx_unlock(&vnode_free_list_mtx);
794 VI_UNLOCK(vp);
795 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
796 vtryrecycle(vp);
797 VFS_UNLOCK_GIANT(vfslocked);
798 /*
799 * If the recycled succeeded this vdrop will actually free
800 * the vnode. If not it will simply place it back on
801 * the free list.
802 */
803 vdrop(vp);
804 mtx_lock(&vnode_free_list_mtx);
805 }
806 }
807 /*
808 * Attempt to recycle vnodes in a context that is always safe to block.
809 * Calling vlrurecycle() from the bowels of filesystem code has some
810 * interesting deadlock problems.
811 */
812 static struct proc *vnlruproc;
813 static int vnlruproc_sig;
814
815 static void
816 vnlru_proc(void)
817 {
818 struct mount *mp, *nmp;
819 int done, vfslocked;
820 struct proc *p = vnlruproc;
821
822 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
823 SHUTDOWN_PRI_FIRST);
824
825 for (;;) {
826 kproc_suspend_check(p);
827 mtx_lock(&vnode_free_list_mtx);
828 if (freevnodes > wantfreevnodes)
829 vnlru_free(freevnodes - wantfreevnodes);
830 if (numvnodes <= desiredvnodes * 9 / 10) {
831 vnlruproc_sig = 0;
832 wakeup(&vnlruproc_sig);
833 msleep(vnlruproc, &vnode_free_list_mtx,
834 PVFS|PDROP, "vlruwt", hz);
835 continue;
836 }
837 mtx_unlock(&vnode_free_list_mtx);
838 done = 0;
839 mtx_lock(&mountlist_mtx);
840 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
841 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
842 nmp = TAILQ_NEXT(mp, mnt_list);
843 continue;
844 }
845 vfslocked = VFS_LOCK_GIANT(mp);
846 done += vlrureclaim(mp);
847 VFS_UNLOCK_GIANT(vfslocked);
848 mtx_lock(&mountlist_mtx);
849 nmp = TAILQ_NEXT(mp, mnt_list);
850 vfs_unbusy(mp);
851 }
852 mtx_unlock(&mountlist_mtx);
853 if (done == 0) {
854 #if 0
855 /* These messages are temporary debugging aids */
856 if (vnlru_nowhere < 5)
857 printf("vnlru process getting nowhere..\n");
858 else if (vnlru_nowhere == 5)
859 printf("vnlru process messages stopped.\n");
860 #endif
861 vnlru_nowhere++;
862 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
863 } else
864 kern_yield(PRI_UNCHANGED);
865 }
866 }
867
868 static struct kproc_desc vnlru_kp = {
869 "vnlru",
870 vnlru_proc,
871 &vnlruproc
872 };
873 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
874 &vnlru_kp);
875
876 /*
877 * Routines having to do with the management of the vnode table.
878 */
879
880 /*
881 * Try to recycle a freed vnode. We abort if anyone picks up a reference
882 * before we actually vgone(). This function must be called with the vnode
883 * held to prevent the vnode from being returned to the free list midway
884 * through vgone().
885 */
886 static int
887 vtryrecycle(struct vnode *vp)
888 {
889 struct mount *vnmp;
890
891 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
892 VNASSERT(vp->v_holdcnt, vp,
893 ("vtryrecycle: Recycling vp %p without a reference.", vp));
894 /*
895 * This vnode may found and locked via some other list, if so we
896 * can't recycle it yet.
897 */
898 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
899 CTR2(KTR_VFS,
900 "%s: impossible to recycle, vp %p lock is already held",
901 __func__, vp);
902 return (EWOULDBLOCK);
903 }
904 /*
905 * Don't recycle if its filesystem is being suspended.
906 */
907 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
908 VOP_UNLOCK(vp, 0);
909 CTR2(KTR_VFS,
910 "%s: impossible to recycle, cannot start the write for %p",
911 __func__, vp);
912 return (EBUSY);
913 }
914 /*
915 * If we got this far, we need to acquire the interlock and see if
916 * anyone picked up this vnode from another list. If not, we will
917 * mark it with DOOMED via vgonel() so that anyone who does find it
918 * will skip over it.
919 */
920 VI_LOCK(vp);
921 if (vp->v_usecount) {
922 VOP_UNLOCK(vp, LK_INTERLOCK);
923 vn_finished_write(vnmp);
924 CTR2(KTR_VFS,
925 "%s: impossible to recycle, %p is already referenced",
926 __func__, vp);
927 return (EBUSY);
928 }
929 if ((vp->v_iflag & VI_DOOMED) == 0)
930 vgonel(vp);
931 VOP_UNLOCK(vp, LK_INTERLOCK);
932 vn_finished_write(vnmp);
933 return (0);
934 }
935
936 /*
937 * Return the next vnode from the free list.
938 */
939 int
940 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
941 struct vnode **vpp)
942 {
943 struct vnode *vp = NULL;
944 struct bufobj *bo;
945
946 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
947 mtx_lock(&vnode_free_list_mtx);
948 /*
949 * Lend our context to reclaim vnodes if they've exceeded the max.
950 */
951 if (freevnodes > wantfreevnodes)
952 vnlru_free(1);
953 /*
954 * Wait for available vnodes.
955 */
956 if (numvnodes > desiredvnodes) {
957 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
958 /*
959 * File system is beeing suspended, we cannot risk a
960 * deadlock here, so allocate new vnode anyway.
961 */
962 if (freevnodes > wantfreevnodes)
963 vnlru_free(freevnodes - wantfreevnodes);
964 goto alloc;
965 }
966 if (vnlruproc_sig == 0) {
967 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
968 wakeup(vnlruproc);
969 }
970 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
971 "vlruwk", hz);
972 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
973 if (numvnodes > desiredvnodes) {
974 mtx_unlock(&vnode_free_list_mtx);
975 return (ENFILE);
976 }
977 #endif
978 }
979 alloc:
980 numvnodes++;
981 mtx_unlock(&vnode_free_list_mtx);
982 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
983 /*
984 * Setup locks.
985 */
986 vp->v_vnlock = &vp->v_lock;
987 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
988 /*
989 * By default, don't allow shared locks unless filesystems
990 * opt-in.
991 */
992 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
993 /*
994 * Initialize bufobj.
995 */
996 bo = &vp->v_bufobj;
997 bo->__bo_vnode = vp;
998 mtx_init(BO_MTX(bo), "bufobj interlock", NULL, MTX_DEF);
999 bo->bo_ops = &buf_ops_bio;
1000 bo->bo_private = vp;
1001 TAILQ_INIT(&bo->bo_clean.bv_hd);
1002 TAILQ_INIT(&bo->bo_dirty.bv_hd);
1003 /*
1004 * Initialize namecache.
1005 */
1006 LIST_INIT(&vp->v_cache_src);
1007 TAILQ_INIT(&vp->v_cache_dst);
1008 /*
1009 * Finalize various vnode identity bits.
1010 */
1011 vp->v_type = VNON;
1012 vp->v_tag = tag;
1013 vp->v_op = vops;
1014 v_incr_usecount(vp);
1015 vp->v_data = 0;
1016 #ifdef MAC
1017 mac_vnode_init(vp);
1018 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1019 mac_vnode_associate_singlelabel(mp, vp);
1020 else if (mp == NULL && vops != &dead_vnodeops)
1021 printf("NULL mp in getnewvnode()\n");
1022 #endif
1023 if (mp != NULL) {
1024 bo->bo_bsize = mp->mnt_stat.f_iosize;
1025 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1026 vp->v_vflag |= VV_NOKNOTE;
1027 }
1028
1029 *vpp = vp;
1030 return (0);
1031 }
1032
1033 /*
1034 * Delete from old mount point vnode list, if on one.
1035 */
1036 static void
1037 delmntque(struct vnode *vp)
1038 {
1039 struct mount *mp;
1040 int active;
1041
1042 mp = vp->v_mount;
1043 if (mp == NULL)
1044 return;
1045 MNT_ILOCK(mp);
1046 VI_LOCK(vp);
1047 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
1048 ("Active vnode list size %d > Vnode list size %d",
1049 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
1050 active = vp->v_iflag & VI_ACTIVE;
1051 vp->v_iflag &= ~VI_ACTIVE;
1052 if (active) {
1053 mtx_lock(&vnode_free_list_mtx);
1054 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
1055 mp->mnt_activevnodelistsize--;
1056 mtx_unlock(&vnode_free_list_mtx);
1057 }
1058 vp->v_mount = NULL;
1059 VI_UNLOCK(vp);
1060 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1061 ("bad mount point vnode list size"));
1062 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1063 mp->mnt_nvnodelistsize--;
1064 MNT_REL(mp);
1065 MNT_IUNLOCK(mp);
1066 }
1067
1068 static void
1069 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1070 {
1071
1072 vp->v_data = NULL;
1073 vp->v_op = &dead_vnodeops;
1074 /* XXX non mp-safe fs may still call insmntque with vnode
1075 unlocked */
1076 if (!VOP_ISLOCKED(vp))
1077 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1078 vgone(vp);
1079 vput(vp);
1080 }
1081
1082 /*
1083 * Insert into list of vnodes for the new mount point, if available.
1084 */
1085 int
1086 insmntque1(struct vnode *vp, struct mount *mp,
1087 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1088 {
1089 int locked;
1090
1091 KASSERT(vp->v_mount == NULL,
1092 ("insmntque: vnode already on per mount vnode list"));
1093 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1094 #ifdef DEBUG_VFS_LOCKS
1095 if (!VFS_NEEDSGIANT(mp))
1096 ASSERT_VOP_ELOCKED(vp,
1097 "insmntque: mp-safe fs and non-locked vp");
1098 #endif
1099 /*
1100 * We acquire the vnode interlock early to ensure that the
1101 * vnode cannot be recycled by another process releasing a
1102 * holdcnt on it before we get it on both the vnode list
1103 * and the active vnode list. The mount mutex protects only
1104 * manipulation of the vnode list and the vnode freelist
1105 * mutex protects only manipulation of the active vnode list.
1106 * Hence the need to hold the vnode interlock throughout.
1107 */
1108 MNT_ILOCK(mp);
1109 VI_LOCK(vp);
1110 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1111 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1112 mp->mnt_nvnodelistsize == 0)) {
1113 locked = VOP_ISLOCKED(vp);
1114 if (!locked || (locked == LK_EXCLUSIVE &&
1115 (vp->v_vflag & VV_FORCEINSMQ) == 0)) {
1116 VI_UNLOCK(vp);
1117 MNT_IUNLOCK(mp);
1118 if (dtr != NULL)
1119 dtr(vp, dtr_arg);
1120 return (EBUSY);
1121 }
1122 }
1123 vp->v_mount = mp;
1124 MNT_REF(mp);
1125 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1126 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1127 ("neg mount point vnode list size"));
1128 mp->mnt_nvnodelistsize++;
1129 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1130 ("Activating already active vnode"));
1131 vp->v_iflag |= VI_ACTIVE;
1132 mtx_lock(&vnode_free_list_mtx);
1133 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
1134 mp->mnt_activevnodelistsize++;
1135 mtx_unlock(&vnode_free_list_mtx);
1136 VI_UNLOCK(vp);
1137 MNT_IUNLOCK(mp);
1138 return (0);
1139 }
1140
1141 int
1142 insmntque(struct vnode *vp, struct mount *mp)
1143 {
1144
1145 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1146 }
1147
1148 /*
1149 * Flush out and invalidate all buffers associated with a bufobj
1150 * Called with the underlying object locked.
1151 */
1152 int
1153 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1154 {
1155 int error;
1156
1157 BO_LOCK(bo);
1158 if (flags & V_SAVE) {
1159 error = bufobj_wwait(bo, slpflag, slptimeo);
1160 if (error) {
1161 BO_UNLOCK(bo);
1162 return (error);
1163 }
1164 if (bo->bo_dirty.bv_cnt > 0) {
1165 BO_UNLOCK(bo);
1166 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1167 return (error);
1168 /*
1169 * XXX We could save a lock/unlock if this was only
1170 * enabled under INVARIANTS
1171 */
1172 BO_LOCK(bo);
1173 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1174 panic("vinvalbuf: dirty bufs");
1175 }
1176 }
1177 /*
1178 * If you alter this loop please notice that interlock is dropped and
1179 * reacquired in flushbuflist. Special care is needed to ensure that
1180 * no race conditions occur from this.
1181 */
1182 do {
1183 error = flushbuflist(&bo->bo_clean,
1184 flags, bo, slpflag, slptimeo);
1185 if (error == 0 && !(flags & V_CLEANONLY))
1186 error = flushbuflist(&bo->bo_dirty,
1187 flags, bo, slpflag, slptimeo);
1188 if (error != 0 && error != EAGAIN) {
1189 BO_UNLOCK(bo);
1190 return (error);
1191 }
1192 } while (error != 0);
1193
1194 /*
1195 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1196 * have write I/O in-progress but if there is a VM object then the
1197 * VM object can also have read-I/O in-progress.
1198 */
1199 do {
1200 bufobj_wwait(bo, 0, 0);
1201 BO_UNLOCK(bo);
1202 if (bo->bo_object != NULL) {
1203 VM_OBJECT_LOCK(bo->bo_object);
1204 vm_object_pip_wait(bo->bo_object, "bovlbx");
1205 VM_OBJECT_UNLOCK(bo->bo_object);
1206 }
1207 BO_LOCK(bo);
1208 } while (bo->bo_numoutput > 0);
1209 BO_UNLOCK(bo);
1210
1211 /*
1212 * Destroy the copy in the VM cache, too.
1213 */
1214 if (bo->bo_object != NULL &&
1215 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
1216 VM_OBJECT_LOCK(bo->bo_object);
1217 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
1218 OBJPR_CLEANONLY : 0);
1219 VM_OBJECT_UNLOCK(bo->bo_object);
1220 }
1221
1222 #ifdef INVARIANTS
1223 BO_LOCK(bo);
1224 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
1225 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1226 panic("vinvalbuf: flush failed");
1227 BO_UNLOCK(bo);
1228 #endif
1229 return (0);
1230 }
1231
1232 /*
1233 * Flush out and invalidate all buffers associated with a vnode.
1234 * Called with the underlying object locked.
1235 */
1236 int
1237 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1238 {
1239
1240 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1241 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1242 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1243 }
1244
1245 /*
1246 * Flush out buffers on the specified list.
1247 *
1248 */
1249 static int
1250 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1251 int slptimeo)
1252 {
1253 struct buf *bp, *nbp;
1254 int retval, error;
1255 daddr_t lblkno;
1256 b_xflags_t xflags;
1257
1258 ASSERT_BO_LOCKED(bo);
1259
1260 retval = 0;
1261 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1262 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1263 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1264 continue;
1265 }
1266 lblkno = 0;
1267 xflags = 0;
1268 if (nbp != NULL) {
1269 lblkno = nbp->b_lblkno;
1270 xflags = nbp->b_xflags &
1271 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1272 }
1273 retval = EAGAIN;
1274 error = BUF_TIMELOCK(bp,
1275 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1276 "flushbuf", slpflag, slptimeo);
1277 if (error) {
1278 BO_LOCK(bo);
1279 return (error != ENOLCK ? error : EAGAIN);
1280 }
1281 KASSERT(bp->b_bufobj == bo,
1282 ("bp %p wrong b_bufobj %p should be %p",
1283 bp, bp->b_bufobj, bo));
1284 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1285 BUF_UNLOCK(bp);
1286 BO_LOCK(bo);
1287 return (EAGAIN);
1288 }
1289 /*
1290 * XXX Since there are no node locks for NFS, I
1291 * believe there is a slight chance that a delayed
1292 * write will occur while sleeping just above, so
1293 * check for it.
1294 */
1295 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1296 (flags & V_SAVE)) {
1297 BO_LOCK(bo);
1298 bremfree(bp);
1299 BO_UNLOCK(bo);
1300 bp->b_flags |= B_ASYNC;
1301 bwrite(bp);
1302 BO_LOCK(bo);
1303 return (EAGAIN); /* XXX: why not loop ? */
1304 }
1305 BO_LOCK(bo);
1306 bremfree(bp);
1307 BO_UNLOCK(bo);
1308 bp->b_flags |= (B_INVAL | B_RELBUF);
1309 bp->b_flags &= ~B_ASYNC;
1310 brelse(bp);
1311 BO_LOCK(bo);
1312 if (nbp != NULL &&
1313 (nbp->b_bufobj != bo ||
1314 nbp->b_lblkno != lblkno ||
1315 (nbp->b_xflags &
1316 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1317 break; /* nbp invalid */
1318 }
1319 return (retval);
1320 }
1321
1322 /*
1323 * Truncate a file's buffer and pages to a specified length. This
1324 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1325 * sync activity.
1326 */
1327 int
1328 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
1329 off_t length, int blksize)
1330 {
1331 struct buf *bp, *nbp;
1332 int anyfreed;
1333 int trunclbn;
1334 struct bufobj *bo;
1335
1336 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__,
1337 vp, cred, blksize, (uintmax_t)length);
1338
1339 /*
1340 * Round up to the *next* lbn.
1341 */
1342 trunclbn = (length + blksize - 1) / blksize;
1343
1344 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1345 restart:
1346 bo = &vp->v_bufobj;
1347 BO_LOCK(bo);
1348 anyfreed = 1;
1349 for (;anyfreed;) {
1350 anyfreed = 0;
1351 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1352 if (bp->b_lblkno < trunclbn)
1353 continue;
1354 if (BUF_LOCK(bp,
1355 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1356 BO_MTX(bo)) == ENOLCK)
1357 goto restart;
1358
1359 BO_LOCK(bo);
1360 bremfree(bp);
1361 BO_UNLOCK(bo);
1362 bp->b_flags |= (B_INVAL | B_RELBUF);
1363 bp->b_flags &= ~B_ASYNC;
1364 brelse(bp);
1365 anyfreed = 1;
1366
1367 BO_LOCK(bo);
1368 if (nbp != NULL &&
1369 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1370 (nbp->b_vp != vp) ||
1371 (nbp->b_flags & B_DELWRI))) {
1372 BO_UNLOCK(bo);
1373 goto restart;
1374 }
1375 }
1376
1377 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1378 if (bp->b_lblkno < trunclbn)
1379 continue;
1380 if (BUF_LOCK(bp,
1381 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1382 BO_MTX(bo)) == ENOLCK)
1383 goto restart;
1384 BO_LOCK(bo);
1385 bremfree(bp);
1386 BO_UNLOCK(bo);
1387 bp->b_flags |= (B_INVAL | B_RELBUF);
1388 bp->b_flags &= ~B_ASYNC;
1389 brelse(bp);
1390 anyfreed = 1;
1391
1392 BO_LOCK(bo);
1393 if (nbp != NULL &&
1394 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1395 (nbp->b_vp != vp) ||
1396 (nbp->b_flags & B_DELWRI) == 0)) {
1397 BO_UNLOCK(bo);
1398 goto restart;
1399 }
1400 }
1401 }
1402
1403 if (length > 0) {
1404 restartsync:
1405 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1406 if (bp->b_lblkno > 0)
1407 continue;
1408 /*
1409 * Since we hold the vnode lock this should only
1410 * fail if we're racing with the buf daemon.
1411 */
1412 if (BUF_LOCK(bp,
1413 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1414 BO_MTX(bo)) == ENOLCK) {
1415 goto restart;
1416 }
1417 VNASSERT((bp->b_flags & B_DELWRI), vp,
1418 ("buf(%p) on dirty queue without DELWRI", bp));
1419
1420 BO_LOCK(bo);
1421 bremfree(bp);
1422 BO_UNLOCK(bo);
1423 bawrite(bp);
1424 BO_LOCK(bo);
1425 goto restartsync;
1426 }
1427 }
1428
1429 bufobj_wwait(bo, 0, 0);
1430 BO_UNLOCK(bo);
1431 vnode_pager_setsize(vp, length);
1432
1433 return (0);
1434 }
1435
1436 /*
1437 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1438 * a vnode.
1439 *
1440 * NOTE: We have to deal with the special case of a background bitmap
1441 * buffer, a situation where two buffers will have the same logical
1442 * block offset. We want (1) only the foreground buffer to be accessed
1443 * in a lookup and (2) must differentiate between the foreground and
1444 * background buffer in the splay tree algorithm because the splay
1445 * tree cannot normally handle multiple entities with the same 'index'.
1446 * We accomplish this by adding differentiating flags to the splay tree's
1447 * numerical domain.
1448 */
1449 static
1450 struct buf *
1451 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1452 {
1453 struct buf dummy;
1454 struct buf *lefttreemax, *righttreemin, *y;
1455
1456 if (root == NULL)
1457 return (NULL);
1458 lefttreemax = righttreemin = &dummy;
1459 for (;;) {
1460 if (lblkno < root->b_lblkno ||
1461 (lblkno == root->b_lblkno &&
1462 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1463 if ((y = root->b_left) == NULL)
1464 break;
1465 if (lblkno < y->b_lblkno) {
1466 /* Rotate right. */
1467 root->b_left = y->b_right;
1468 y->b_right = root;
1469 root = y;
1470 if ((y = root->b_left) == NULL)
1471 break;
1472 }
1473 /* Link into the new root's right tree. */
1474 righttreemin->b_left = root;
1475 righttreemin = root;
1476 } else if (lblkno > root->b_lblkno ||
1477 (lblkno == root->b_lblkno &&
1478 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1479 if ((y = root->b_right) == NULL)
1480 break;
1481 if (lblkno > y->b_lblkno) {
1482 /* Rotate left. */
1483 root->b_right = y->b_left;
1484 y->b_left = root;
1485 root = y;
1486 if ((y = root->b_right) == NULL)
1487 break;
1488 }
1489 /* Link into the new root's left tree. */
1490 lefttreemax->b_right = root;
1491 lefttreemax = root;
1492 } else {
1493 break;
1494 }
1495 root = y;
1496 }
1497 /* Assemble the new root. */
1498 lefttreemax->b_right = root->b_left;
1499 righttreemin->b_left = root->b_right;
1500 root->b_left = dummy.b_right;
1501 root->b_right = dummy.b_left;
1502 return (root);
1503 }
1504
1505 static void
1506 buf_vlist_remove(struct buf *bp)
1507 {
1508 struct buf *root;
1509 struct bufv *bv;
1510
1511 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1512 ASSERT_BO_LOCKED(bp->b_bufobj);
1513 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1514 (BX_VNDIRTY|BX_VNCLEAN),
1515 ("buf_vlist_remove: Buf %p is on two lists", bp));
1516 if (bp->b_xflags & BX_VNDIRTY)
1517 bv = &bp->b_bufobj->bo_dirty;
1518 else
1519 bv = &bp->b_bufobj->bo_clean;
1520 if (bp != bv->bv_root) {
1521 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1522 KASSERT(root == bp, ("splay lookup failed in remove"));
1523 }
1524 if (bp->b_left == NULL) {
1525 root = bp->b_right;
1526 } else {
1527 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1528 root->b_right = bp->b_right;
1529 }
1530 bv->bv_root = root;
1531 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1532 bv->bv_cnt--;
1533 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1534 }
1535
1536 /*
1537 * Add the buffer to the sorted clean or dirty block list using a
1538 * splay tree algorithm.
1539 *
1540 * NOTE: xflags is passed as a constant, optimizing this inline function!
1541 */
1542 static void
1543 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1544 {
1545 struct buf *root;
1546 struct bufv *bv;
1547
1548 ASSERT_BO_LOCKED(bo);
1549 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1550 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1551 bp->b_xflags |= xflags;
1552 if (xflags & BX_VNDIRTY)
1553 bv = &bo->bo_dirty;
1554 else
1555 bv = &bo->bo_clean;
1556
1557 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1558 if (root == NULL) {
1559 bp->b_left = NULL;
1560 bp->b_right = NULL;
1561 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1562 } else if (bp->b_lblkno < root->b_lblkno ||
1563 (bp->b_lblkno == root->b_lblkno &&
1564 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1565 bp->b_left = root->b_left;
1566 bp->b_right = root;
1567 root->b_left = NULL;
1568 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1569 } else {
1570 bp->b_right = root->b_right;
1571 bp->b_left = root;
1572 root->b_right = NULL;
1573 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1574 }
1575 bv->bv_cnt++;
1576 bv->bv_root = bp;
1577 }
1578
1579 /*
1580 * Lookup a buffer using the splay tree. Note that we specifically avoid
1581 * shadow buffers used in background bitmap writes.
1582 *
1583 * This code isn't quite efficient as it could be because we are maintaining
1584 * two sorted lists and do not know which list the block resides in.
1585 *
1586 * During a "make buildworld" the desired buffer is found at one of
1587 * the roots more than 60% of the time. Thus, checking both roots
1588 * before performing either splay eliminates unnecessary splays on the
1589 * first tree splayed.
1590 */
1591 struct buf *
1592 gbincore(struct bufobj *bo, daddr_t lblkno)
1593 {
1594 struct buf *bp;
1595
1596 ASSERT_BO_LOCKED(bo);
1597 if ((bp = bo->bo_clean.bv_root) != NULL &&
1598 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1599 return (bp);
1600 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1601 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1602 return (bp);
1603 if ((bp = bo->bo_clean.bv_root) != NULL) {
1604 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1605 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1606 return (bp);
1607 }
1608 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1609 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1610 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1611 return (bp);
1612 }
1613 return (NULL);
1614 }
1615
1616 /*
1617 * Associate a buffer with a vnode.
1618 */
1619 void
1620 bgetvp(struct vnode *vp, struct buf *bp)
1621 {
1622 struct bufobj *bo;
1623
1624 bo = &vp->v_bufobj;
1625 ASSERT_BO_LOCKED(bo);
1626 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1627
1628 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1629 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1630 ("bgetvp: bp already attached! %p", bp));
1631
1632 vhold(vp);
1633 if (VFS_NEEDSGIANT(vp->v_mount) || bo->bo_flag & BO_NEEDSGIANT)
1634 bp->b_flags |= B_NEEDSGIANT;
1635 bp->b_vp = vp;
1636 bp->b_bufobj = bo;
1637 /*
1638 * Insert onto list for new vnode.
1639 */
1640 buf_vlist_add(bp, bo, BX_VNCLEAN);
1641 }
1642
1643 /*
1644 * Disassociate a buffer from a vnode.
1645 */
1646 void
1647 brelvp(struct buf *bp)
1648 {
1649 struct bufobj *bo;
1650 struct vnode *vp;
1651
1652 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1653 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1654
1655 /*
1656 * Delete from old vnode list, if on one.
1657 */
1658 vp = bp->b_vp; /* XXX */
1659 bo = bp->b_bufobj;
1660 BO_LOCK(bo);
1661 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1662 buf_vlist_remove(bp);
1663 else
1664 panic("brelvp: Buffer %p not on queue.", bp);
1665 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1666 bo->bo_flag &= ~BO_ONWORKLST;
1667 mtx_lock(&sync_mtx);
1668 LIST_REMOVE(bo, bo_synclist);
1669 syncer_worklist_len--;
1670 mtx_unlock(&sync_mtx);
1671 }
1672 bp->b_flags &= ~B_NEEDSGIANT;
1673 bp->b_vp = NULL;
1674 bp->b_bufobj = NULL;
1675 BO_UNLOCK(bo);
1676 vdrop(vp);
1677 }
1678
1679 /*
1680 * Add an item to the syncer work queue.
1681 */
1682 static void
1683 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1684 {
1685 int queue, slot;
1686
1687 ASSERT_BO_LOCKED(bo);
1688
1689 mtx_lock(&sync_mtx);
1690 if (bo->bo_flag & BO_ONWORKLST)
1691 LIST_REMOVE(bo, bo_synclist);
1692 else {
1693 bo->bo_flag |= BO_ONWORKLST;
1694 syncer_worklist_len++;
1695 }
1696
1697 if (delay > syncer_maxdelay - 2)
1698 delay = syncer_maxdelay - 2;
1699 slot = (syncer_delayno + delay) & syncer_mask;
1700
1701 queue = VFS_NEEDSGIANT(bo->__bo_vnode->v_mount) ? WI_GIANTQ :
1702 WI_MPSAFEQ;
1703 LIST_INSERT_HEAD(&syncer_workitem_pending[queue][slot], bo,
1704 bo_synclist);
1705 mtx_unlock(&sync_mtx);
1706 }
1707
1708 static int
1709 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1710 {
1711 int error, len;
1712
1713 mtx_lock(&sync_mtx);
1714 len = syncer_worklist_len - sync_vnode_count;
1715 mtx_unlock(&sync_mtx);
1716 error = SYSCTL_OUT(req, &len, sizeof(len));
1717 return (error);
1718 }
1719
1720 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1721 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1722
1723 static struct proc *updateproc;
1724 static void sched_sync(void);
1725 static struct kproc_desc up_kp = {
1726 "syncer",
1727 sched_sync,
1728 &updateproc
1729 };
1730 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
1731
1732 static int
1733 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
1734 {
1735 struct vnode *vp;
1736 struct mount *mp;
1737
1738 *bo = LIST_FIRST(slp);
1739 if (*bo == NULL)
1740 return (0);
1741 vp = (*bo)->__bo_vnode; /* XXX */
1742 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
1743 return (1);
1744 /*
1745 * We use vhold in case the vnode does not
1746 * successfully sync. vhold prevents the vnode from
1747 * going away when we unlock the sync_mtx so that
1748 * we can acquire the vnode interlock.
1749 */
1750 vholdl(vp);
1751 mtx_unlock(&sync_mtx);
1752 VI_UNLOCK(vp);
1753 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1754 vdrop(vp);
1755 mtx_lock(&sync_mtx);
1756 return (*bo == LIST_FIRST(slp));
1757 }
1758 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1759 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1760 VOP_UNLOCK(vp, 0);
1761 vn_finished_write(mp);
1762 BO_LOCK(*bo);
1763 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
1764 /*
1765 * Put us back on the worklist. The worklist
1766 * routine will remove us from our current
1767 * position and then add us back in at a later
1768 * position.
1769 */
1770 vn_syncer_add_to_worklist(*bo, syncdelay);
1771 }
1772 BO_UNLOCK(*bo);
1773 vdrop(vp);
1774 mtx_lock(&sync_mtx);
1775 return (0);
1776 }
1777
1778 /*
1779 * System filesystem synchronizer daemon.
1780 */
1781 static void
1782 sched_sync(void)
1783 {
1784 struct synclist *gnext, *next;
1785 struct synclist *gslp, *slp;
1786 struct bufobj *bo;
1787 long starttime;
1788 struct thread *td = curthread;
1789 int last_work_seen;
1790 int net_worklist_len;
1791 int syncer_final_iter;
1792 int first_printf;
1793 int error;
1794
1795 last_work_seen = 0;
1796 syncer_final_iter = 0;
1797 first_printf = 1;
1798 syncer_state = SYNCER_RUNNING;
1799 starttime = time_uptime;
1800 td->td_pflags |= TDP_NORUNNINGBUF;
1801
1802 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1803 SHUTDOWN_PRI_LAST);
1804
1805 mtx_lock(&sync_mtx);
1806 for (;;) {
1807 if (syncer_state == SYNCER_FINAL_DELAY &&
1808 syncer_final_iter == 0) {
1809 mtx_unlock(&sync_mtx);
1810 kproc_suspend_check(td->td_proc);
1811 mtx_lock(&sync_mtx);
1812 }
1813 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1814 if (syncer_state != SYNCER_RUNNING &&
1815 starttime != time_uptime) {
1816 if (first_printf) {
1817 printf("\nSyncing disks, vnodes remaining...");
1818 first_printf = 0;
1819 }
1820 printf("%d ", net_worklist_len);
1821 }
1822 starttime = time_uptime;
1823
1824 /*
1825 * Push files whose dirty time has expired. Be careful
1826 * of interrupt race on slp queue.
1827 *
1828 * Skip over empty worklist slots when shutting down.
1829 */
1830 do {
1831 slp = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno];
1832 gslp = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno];
1833 syncer_delayno += 1;
1834 if (syncer_delayno == syncer_maxdelay)
1835 syncer_delayno = 0;
1836 next = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno];
1837 gnext = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno];
1838 /*
1839 * If the worklist has wrapped since the
1840 * it was emptied of all but syncer vnodes,
1841 * switch to the FINAL_DELAY state and run
1842 * for one more second.
1843 */
1844 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1845 net_worklist_len == 0 &&
1846 last_work_seen == syncer_delayno) {
1847 syncer_state = SYNCER_FINAL_DELAY;
1848 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1849 }
1850 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1851 LIST_EMPTY(gslp) && syncer_worklist_len > 0);
1852
1853 /*
1854 * Keep track of the last time there was anything
1855 * on the worklist other than syncer vnodes.
1856 * Return to the SHUTTING_DOWN state if any
1857 * new work appears.
1858 */
1859 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1860 last_work_seen = syncer_delayno;
1861 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1862 syncer_state = SYNCER_SHUTTING_DOWN;
1863 while (!LIST_EMPTY(slp)) {
1864 error = sync_vnode(slp, &bo, td);
1865 if (error == 1) {
1866 LIST_REMOVE(bo, bo_synclist);
1867 LIST_INSERT_HEAD(next, bo, bo_synclist);
1868 continue;
1869 }
1870
1871 if (first_printf == 0)
1872 wdog_kern_pat(WD_LASTVAL);
1873
1874 }
1875 if (!LIST_EMPTY(gslp)) {
1876 mtx_unlock(&sync_mtx);
1877 mtx_lock(&Giant);
1878 mtx_lock(&sync_mtx);
1879 while (!LIST_EMPTY(gslp)) {
1880 error = sync_vnode(gslp, &bo, td);
1881 if (error == 1) {
1882 LIST_REMOVE(bo, bo_synclist);
1883 LIST_INSERT_HEAD(gnext, bo,
1884 bo_synclist);
1885 continue;
1886 }
1887 }
1888 mtx_unlock(&Giant);
1889 }
1890 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1891 syncer_final_iter--;
1892 /*
1893 * The variable rushjob allows the kernel to speed up the
1894 * processing of the filesystem syncer process. A rushjob
1895 * value of N tells the filesystem syncer to process the next
1896 * N seconds worth of work on its queue ASAP. Currently rushjob
1897 * is used by the soft update code to speed up the filesystem
1898 * syncer process when the incore state is getting so far
1899 * ahead of the disk that the kernel memory pool is being
1900 * threatened with exhaustion.
1901 */
1902 if (rushjob > 0) {
1903 rushjob -= 1;
1904 continue;
1905 }
1906 /*
1907 * Just sleep for a short period of time between
1908 * iterations when shutting down to allow some I/O
1909 * to happen.
1910 *
1911 * If it has taken us less than a second to process the
1912 * current work, then wait. Otherwise start right over
1913 * again. We can still lose time if any single round
1914 * takes more than two seconds, but it does not really
1915 * matter as we are just trying to generally pace the
1916 * filesystem activity.
1917 */
1918 if (syncer_state != SYNCER_RUNNING ||
1919 time_uptime == starttime) {
1920 thread_lock(td);
1921 sched_prio(td, PPAUSE);
1922 thread_unlock(td);
1923 }
1924 if (syncer_state != SYNCER_RUNNING)
1925 cv_timedwait(&sync_wakeup, &sync_mtx,
1926 hz / SYNCER_SHUTDOWN_SPEEDUP);
1927 else if (time_uptime == starttime)
1928 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
1929 }
1930 }
1931
1932 /*
1933 * Request the syncer daemon to speed up its work.
1934 * We never push it to speed up more than half of its
1935 * normal turn time, otherwise it could take over the cpu.
1936 */
1937 int
1938 speedup_syncer(void)
1939 {
1940 int ret = 0;
1941
1942 mtx_lock(&sync_mtx);
1943 if (rushjob < syncdelay / 2) {
1944 rushjob += 1;
1945 stat_rush_requests += 1;
1946 ret = 1;
1947 }
1948 mtx_unlock(&sync_mtx);
1949 cv_broadcast(&sync_wakeup);
1950 return (ret);
1951 }
1952
1953 /*
1954 * Tell the syncer to speed up its work and run though its work
1955 * list several times, then tell it to shut down.
1956 */
1957 static void
1958 syncer_shutdown(void *arg, int howto)
1959 {
1960
1961 if (howto & RB_NOSYNC)
1962 return;
1963 mtx_lock(&sync_mtx);
1964 syncer_state = SYNCER_SHUTTING_DOWN;
1965 rushjob = 0;
1966 mtx_unlock(&sync_mtx);
1967 cv_broadcast(&sync_wakeup);
1968 kproc_shutdown(arg, howto);
1969 }
1970
1971 /*
1972 * Reassign a buffer from one vnode to another.
1973 * Used to assign file specific control information
1974 * (indirect blocks) to the vnode to which they belong.
1975 */
1976 void
1977 reassignbuf(struct buf *bp)
1978 {
1979 struct vnode *vp;
1980 struct bufobj *bo;
1981 int delay;
1982 #ifdef INVARIANTS
1983 struct bufv *bv;
1984 #endif
1985
1986 vp = bp->b_vp;
1987 bo = bp->b_bufobj;
1988 ++reassignbufcalls;
1989
1990 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1991 bp, bp->b_vp, bp->b_flags);
1992 /*
1993 * B_PAGING flagged buffers cannot be reassigned because their vp
1994 * is not fully linked in.
1995 */
1996 if (bp->b_flags & B_PAGING)
1997 panic("cannot reassign paging buffer");
1998
1999 /*
2000 * Delete from old vnode list, if on one.
2001 */
2002 BO_LOCK(bo);
2003 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2004 buf_vlist_remove(bp);
2005 else
2006 panic("reassignbuf: Buffer %p not on queue.", bp);
2007 /*
2008 * If dirty, put on list of dirty buffers; otherwise insert onto list
2009 * of clean buffers.
2010 */
2011 if (bp->b_flags & B_DELWRI) {
2012 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
2013 switch (vp->v_type) {
2014 case VDIR:
2015 delay = dirdelay;
2016 break;
2017 case VCHR:
2018 delay = metadelay;
2019 break;
2020 default:
2021 delay = filedelay;
2022 }
2023 vn_syncer_add_to_worklist(bo, delay);
2024 }
2025 buf_vlist_add(bp, bo, BX_VNDIRTY);
2026 } else {
2027 buf_vlist_add(bp, bo, BX_VNCLEAN);
2028
2029 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2030 mtx_lock(&sync_mtx);
2031 LIST_REMOVE(bo, bo_synclist);
2032 syncer_worklist_len--;
2033 mtx_unlock(&sync_mtx);
2034 bo->bo_flag &= ~BO_ONWORKLST;
2035 }
2036 }
2037 #ifdef INVARIANTS
2038 bv = &bo->bo_clean;
2039 bp = TAILQ_FIRST(&bv->bv_hd);
2040 KASSERT(bp == NULL || bp->b_bufobj == bo,
2041 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2042 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2043 KASSERT(bp == NULL || bp->b_bufobj == bo,
2044 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2045 bv = &bo->bo_dirty;
2046 bp = TAILQ_FIRST(&bv->bv_hd);
2047 KASSERT(bp == NULL || bp->b_bufobj == bo,
2048 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2049 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2050 KASSERT(bp == NULL || bp->b_bufobj == bo,
2051 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2052 #endif
2053 BO_UNLOCK(bo);
2054 }
2055
2056 /*
2057 * Increment the use and hold counts on the vnode, taking care to reference
2058 * the driver's usecount if this is a chardev. The vholdl() will remove
2059 * the vnode from the free list if it is presently free. Requires the
2060 * vnode interlock and returns with it held.
2061 */
2062 static void
2063 v_incr_usecount(struct vnode *vp)
2064 {
2065
2066 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2067 vp->v_usecount++;
2068 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2069 dev_lock();
2070 vp->v_rdev->si_usecount++;
2071 dev_unlock();
2072 }
2073 vholdl(vp);
2074 }
2075
2076 /*
2077 * Turn a holdcnt into a use+holdcnt such that only one call to
2078 * v_decr_usecount is needed.
2079 */
2080 static void
2081 v_upgrade_usecount(struct vnode *vp)
2082 {
2083
2084 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2085 vp->v_usecount++;
2086 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2087 dev_lock();
2088 vp->v_rdev->si_usecount++;
2089 dev_unlock();
2090 }
2091 }
2092
2093 /*
2094 * Decrement the vnode use and hold count along with the driver's usecount
2095 * if this is a chardev. The vdropl() below releases the vnode interlock
2096 * as it may free the vnode.
2097 */
2098 static void
2099 v_decr_usecount(struct vnode *vp)
2100 {
2101
2102 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2103 VNASSERT(vp->v_usecount > 0, vp,
2104 ("v_decr_usecount: negative usecount"));
2105 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2106 vp->v_usecount--;
2107 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2108 dev_lock();
2109 vp->v_rdev->si_usecount--;
2110 dev_unlock();
2111 }
2112 vdropl(vp);
2113 }
2114
2115 /*
2116 * Decrement only the use count and driver use count. This is intended to
2117 * be paired with a follow on vdropl() to release the remaining hold count.
2118 * In this way we may vgone() a vnode with a 0 usecount without risk of
2119 * having it end up on a free list because the hold count is kept above 0.
2120 */
2121 static void
2122 v_decr_useonly(struct vnode *vp)
2123 {
2124
2125 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2126 VNASSERT(vp->v_usecount > 0, vp,
2127 ("v_decr_useonly: negative usecount"));
2128 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2129 vp->v_usecount--;
2130 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2131 dev_lock();
2132 vp->v_rdev->si_usecount--;
2133 dev_unlock();
2134 }
2135 }
2136
2137 /*
2138 * Grab a particular vnode from the free list, increment its
2139 * reference count and lock it. VI_DOOMED is set if the vnode
2140 * is being destroyed. Only callers who specify LK_RETRY will
2141 * see doomed vnodes. If inactive processing was delayed in
2142 * vput try to do it here.
2143 */
2144 int
2145 vget(struct vnode *vp, int flags, struct thread *td)
2146 {
2147 int error;
2148
2149 error = 0;
2150 VFS_ASSERT_GIANT(vp->v_mount);
2151 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2152 ("vget: invalid lock operation"));
2153 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2154
2155 if ((flags & LK_INTERLOCK) == 0)
2156 VI_LOCK(vp);
2157 vholdl(vp);
2158 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) {
2159 vdrop(vp);
2160 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2161 vp);
2162 return (error);
2163 }
2164 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2165 panic("vget: vn_lock failed to return ENOENT\n");
2166 VI_LOCK(vp);
2167 /* Upgrade our holdcnt to a usecount. */
2168 v_upgrade_usecount(vp);
2169 /*
2170 * We don't guarantee that any particular close will
2171 * trigger inactive processing so just make a best effort
2172 * here at preventing a reference to a removed file. If
2173 * we don't succeed no harm is done.
2174 */
2175 if (vp->v_iflag & VI_OWEINACT) {
2176 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2177 (flags & LK_NOWAIT) == 0)
2178 vinactive(vp, td);
2179 vp->v_iflag &= ~VI_OWEINACT;
2180 }
2181 VI_UNLOCK(vp);
2182 return (0);
2183 }
2184
2185 /*
2186 * Increase the reference count of a vnode.
2187 */
2188 void
2189 vref(struct vnode *vp)
2190 {
2191
2192 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2193 VI_LOCK(vp);
2194 v_incr_usecount(vp);
2195 VI_UNLOCK(vp);
2196 }
2197
2198 /*
2199 * Return reference count of a vnode.
2200 *
2201 * The results of this call are only guaranteed when some mechanism other
2202 * than the VI lock is used to stop other processes from gaining references
2203 * to the vnode. This may be the case if the caller holds the only reference.
2204 * This is also useful when stale data is acceptable as race conditions may
2205 * be accounted for by some other means.
2206 */
2207 int
2208 vrefcnt(struct vnode *vp)
2209 {
2210 int usecnt;
2211
2212 VI_LOCK(vp);
2213 usecnt = vp->v_usecount;
2214 VI_UNLOCK(vp);
2215
2216 return (usecnt);
2217 }
2218
2219 #define VPUTX_VRELE 1
2220 #define VPUTX_VPUT 2
2221 #define VPUTX_VUNREF 3
2222
2223 static void
2224 vputx(struct vnode *vp, int func)
2225 {
2226 int error;
2227
2228 KASSERT(vp != NULL, ("vputx: null vp"));
2229 if (func == VPUTX_VUNREF)
2230 ASSERT_VOP_LOCKED(vp, "vunref");
2231 else if (func == VPUTX_VPUT)
2232 ASSERT_VOP_LOCKED(vp, "vput");
2233 else
2234 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2235 VFS_ASSERT_GIANT(vp->v_mount);
2236 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2237 VI_LOCK(vp);
2238
2239 /* Skip this v_writecount check if we're going to panic below. */
2240 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2241 ("vputx: missed vn_close"));
2242 error = 0;
2243
2244 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2245 vp->v_usecount == 1)) {
2246 if (func == VPUTX_VPUT)
2247 VOP_UNLOCK(vp, 0);
2248 v_decr_usecount(vp);
2249 return;
2250 }
2251
2252 if (vp->v_usecount != 1) {
2253 vprint("vputx: negative ref count", vp);
2254 panic("vputx: negative ref cnt");
2255 }
2256 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
2257 /*
2258 * We want to hold the vnode until the inactive finishes to
2259 * prevent vgone() races. We drop the use count here and the
2260 * hold count below when we're done.
2261 */
2262 v_decr_useonly(vp);
2263 /*
2264 * We must call VOP_INACTIVE with the node locked. Mark
2265 * as VI_DOINGINACT to avoid recursion.
2266 */
2267 vp->v_iflag |= VI_OWEINACT;
2268 switch (func) {
2269 case VPUTX_VRELE:
2270 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2271 VI_LOCK(vp);
2272 break;
2273 case VPUTX_VPUT:
2274 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2275 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
2276 LK_NOWAIT);
2277 VI_LOCK(vp);
2278 }
2279 break;
2280 case VPUTX_VUNREF:
2281 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
2282 error = EBUSY;
2283 break;
2284 }
2285 if (vp->v_usecount > 0)
2286 vp->v_iflag &= ~VI_OWEINACT;
2287 if (error == 0) {
2288 if (vp->v_iflag & VI_OWEINACT)
2289 vinactive(vp, curthread);
2290 if (func != VPUTX_VUNREF)
2291 VOP_UNLOCK(vp, 0);
2292 }
2293 vdropl(vp);
2294 }
2295
2296 /*
2297 * Vnode put/release.
2298 * If count drops to zero, call inactive routine and return to freelist.
2299 */
2300 void
2301 vrele(struct vnode *vp)
2302 {
2303
2304 vputx(vp, VPUTX_VRELE);
2305 }
2306
2307 /*
2308 * Release an already locked vnode. This give the same effects as
2309 * unlock+vrele(), but takes less time and avoids releasing and
2310 * re-aquiring the lock (as vrele() acquires the lock internally.)
2311 */
2312 void
2313 vput(struct vnode *vp)
2314 {
2315
2316 vputx(vp, VPUTX_VPUT);
2317 }
2318
2319 /*
2320 * Release an exclusively locked vnode. Do not unlock the vnode lock.
2321 */
2322 void
2323 vunref(struct vnode *vp)
2324 {
2325
2326 vputx(vp, VPUTX_VUNREF);
2327 }
2328
2329 /*
2330 * Somebody doesn't want the vnode recycled.
2331 */
2332 void
2333 vhold(struct vnode *vp)
2334 {
2335
2336 VI_LOCK(vp);
2337 vholdl(vp);
2338 VI_UNLOCK(vp);
2339 }
2340
2341 /*
2342 * Increase the hold count and activate if this is the first reference.
2343 */
2344 void
2345 vholdl(struct vnode *vp)
2346 {
2347 struct mount *mp;
2348
2349 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2350 vp->v_holdcnt++;
2351 if (!VSHOULDBUSY(vp))
2352 return;
2353 ASSERT_VI_LOCKED(vp, "vholdl");
2354 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
2355 VNASSERT(vp->v_op != NULL, vp, ("vholdl: vnode already reclaimed."));
2356 /*
2357 * Remove a vnode from the free list, mark it as in use,
2358 * and put it on the active list.
2359 */
2360 mtx_lock(&vnode_free_list_mtx);
2361 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
2362 freevnodes--;
2363 vp->v_iflag &= ~(VI_FREE|VI_AGE);
2364 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
2365 ("Activating already active vnode"));
2366 vp->v_iflag |= VI_ACTIVE;
2367 mp = vp->v_mount;
2368 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
2369 mp->mnt_activevnodelistsize++;
2370 mtx_unlock(&vnode_free_list_mtx);
2371 }
2372
2373 /*
2374 * Note that there is one less who cares about this vnode.
2375 * vdrop() is the opposite of vhold().
2376 */
2377 void
2378 vdrop(struct vnode *vp)
2379 {
2380
2381 VI_LOCK(vp);
2382 vdropl(vp);
2383 }
2384
2385 /*
2386 * Drop the hold count of the vnode. If this is the last reference to
2387 * the vnode we place it on the free list unless it has been vgone'd
2388 * (marked VI_DOOMED) in which case we will free it.
2389 */
2390 void
2391 vdropl(struct vnode *vp)
2392 {
2393 struct bufobj *bo;
2394 struct mount *mp;
2395 int active;
2396
2397 ASSERT_VI_LOCKED(vp, "vdropl");
2398 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2399 if (vp->v_holdcnt <= 0)
2400 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2401 vp->v_holdcnt--;
2402 if (vp->v_holdcnt > 0) {
2403 VI_UNLOCK(vp);
2404 return;
2405 }
2406 if ((vp->v_iflag & VI_DOOMED) == 0) {
2407 /*
2408 * Mark a vnode as free: remove it from its active list
2409 * and put it up for recycling on the freelist.
2410 */
2411 VNASSERT(vp->v_op != NULL, vp,
2412 ("vdropl: vnode already reclaimed."));
2413 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2414 ("vnode already free"));
2415 VNASSERT(VSHOULDFREE(vp), vp,
2416 ("vdropl: freeing when we shouldn't"));
2417 active = vp->v_iflag & VI_ACTIVE;
2418 vp->v_iflag &= ~VI_ACTIVE;
2419 mp = vp->v_mount;
2420 mtx_lock(&vnode_free_list_mtx);
2421 if (active) {
2422 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp,
2423 v_actfreelist);
2424 mp->mnt_activevnodelistsize--;
2425 }
2426 if (vp->v_iflag & VI_AGE) {
2427 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_actfreelist);
2428 } else {
2429 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
2430 }
2431 freevnodes++;
2432 vp->v_iflag &= ~VI_AGE;
2433 vp->v_iflag |= VI_FREE;
2434 mtx_unlock(&vnode_free_list_mtx);
2435 VI_UNLOCK(vp);
2436 return;
2437 }
2438 /*
2439 * The vnode has been marked for destruction, so free it.
2440 */
2441 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2442 mtx_lock(&vnode_free_list_mtx);
2443 numvnodes--;
2444 mtx_unlock(&vnode_free_list_mtx);
2445 bo = &vp->v_bufobj;
2446 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2447 ("cleaned vnode still on the free list."));
2448 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2449 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
2450 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2451 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2452 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2453 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2454 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
2455 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2456 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
2457 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
2458 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
2459 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
2460 VI_UNLOCK(vp);
2461 #ifdef MAC
2462 mac_vnode_destroy(vp);
2463 #endif
2464 if (vp->v_pollinfo != NULL)
2465 destroy_vpollinfo(vp->v_pollinfo);
2466 #ifdef INVARIANTS
2467 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
2468 vp->v_op = NULL;
2469 #endif
2470 lockdestroy(vp->v_vnlock);
2471 mtx_destroy(&vp->v_interlock);
2472 mtx_destroy(BO_MTX(bo));
2473 uma_zfree(vnode_zone, vp);
2474 }
2475
2476 /*
2477 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2478 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2479 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2480 * failed lock upgrade.
2481 */
2482 void
2483 vinactive(struct vnode *vp, struct thread *td)
2484 {
2485 struct vm_object *obj;
2486
2487 ASSERT_VOP_ELOCKED(vp, "vinactive");
2488 ASSERT_VI_LOCKED(vp, "vinactive");
2489 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2490 ("vinactive: recursed on VI_DOINGINACT"));
2491 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2492 vp->v_iflag |= VI_DOINGINACT;
2493 vp->v_iflag &= ~VI_OWEINACT;
2494 VI_UNLOCK(vp);
2495 /*
2496 * Before moving off the active list, we must be sure that any
2497 * modified pages are on the vnode's dirty list since these will
2498 * no longer be checked once the vnode is on the inactive list.
2499 */
2500 obj = vp->v_object;
2501 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
2502 VM_OBJECT_LOCK(obj);
2503 vm_object_page_clean(obj, 0, 0, OBJPC_NOSYNC);
2504 VM_OBJECT_UNLOCK(obj);
2505 }
2506 VOP_INACTIVE(vp, td);
2507 VI_LOCK(vp);
2508 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2509 ("vinactive: lost VI_DOINGINACT"));
2510 vp->v_iflag &= ~VI_DOINGINACT;
2511 }
2512
2513 /*
2514 * Remove any vnodes in the vnode table belonging to mount point mp.
2515 *
2516 * If FORCECLOSE is not specified, there should not be any active ones,
2517 * return error if any are found (nb: this is a user error, not a
2518 * system error). If FORCECLOSE is specified, detach any active vnodes
2519 * that are found.
2520 *
2521 * If WRITECLOSE is set, only flush out regular file vnodes open for
2522 * writing.
2523 *
2524 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2525 *
2526 * `rootrefs' specifies the base reference count for the root vnode
2527 * of this filesystem. The root vnode is considered busy if its
2528 * v_usecount exceeds this value. On a successful return, vflush(, td)
2529 * will call vrele() on the root vnode exactly rootrefs times.
2530 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2531 * be zero.
2532 */
2533 #ifdef DIAGNOSTIC
2534 static int busyprt = 0; /* print out busy vnodes */
2535 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
2536 #endif
2537
2538 int
2539 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
2540 {
2541 struct vnode *vp, *mvp, *rootvp = NULL;
2542 struct vattr vattr;
2543 int busy = 0, error;
2544
2545 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
2546 rootrefs, flags);
2547 if (rootrefs > 0) {
2548 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2549 ("vflush: bad args"));
2550 /*
2551 * Get the filesystem root vnode. We can vput() it
2552 * immediately, since with rootrefs > 0, it won't go away.
2553 */
2554 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
2555 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
2556 __func__, error);
2557 return (error);
2558 }
2559 vput(rootvp);
2560 }
2561 loop:
2562 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
2563 vholdl(vp);
2564 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
2565 if (error) {
2566 vdrop(vp);
2567 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2568 goto loop;
2569 }
2570 /*
2571 * Skip over a vnodes marked VV_SYSTEM.
2572 */
2573 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2574 VOP_UNLOCK(vp, 0);
2575 vdrop(vp);
2576 continue;
2577 }
2578 /*
2579 * If WRITECLOSE is set, flush out unlinked but still open
2580 * files (even if open only for reading) and regular file
2581 * vnodes open for writing.
2582 */
2583 if (flags & WRITECLOSE) {
2584 if (vp->v_object != NULL) {
2585 VM_OBJECT_LOCK(vp->v_object);
2586 vm_object_page_clean(vp->v_object, 0, 0, 0);
2587 VM_OBJECT_UNLOCK(vp->v_object);
2588 }
2589 error = VOP_FSYNC(vp, MNT_WAIT, td);
2590 if (error != 0) {
2591 VOP_UNLOCK(vp, 0);
2592 vdrop(vp);
2593 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2594 return (error);
2595 }
2596 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
2597 VI_LOCK(vp);
2598
2599 if ((vp->v_type == VNON ||
2600 (error == 0 && vattr.va_nlink > 0)) &&
2601 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2602 VOP_UNLOCK(vp, 0);
2603 vdropl(vp);
2604 continue;
2605 }
2606 } else
2607 VI_LOCK(vp);
2608 /*
2609 * With v_usecount == 0, all we need to do is clear out the
2610 * vnode data structures and we are done.
2611 *
2612 * If FORCECLOSE is set, forcibly close the vnode.
2613 */
2614 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2615 VNASSERT(vp->v_usecount == 0 ||
2616 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2617 ("device VNODE %p is FORCECLOSED", vp));
2618 vgonel(vp);
2619 } else {
2620 busy++;
2621 #ifdef DIAGNOSTIC
2622 if (busyprt)
2623 vprint("vflush: busy vnode", vp);
2624 #endif
2625 }
2626 VOP_UNLOCK(vp, 0);
2627 vdropl(vp);
2628 }
2629 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2630 /*
2631 * If just the root vnode is busy, and if its refcount
2632 * is equal to `rootrefs', then go ahead and kill it.
2633 */
2634 VI_LOCK(rootvp);
2635 KASSERT(busy > 0, ("vflush: not busy"));
2636 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2637 ("vflush: usecount %d < rootrefs %d",
2638 rootvp->v_usecount, rootrefs));
2639 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2640 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
2641 vgone(rootvp);
2642 VOP_UNLOCK(rootvp, 0);
2643 busy = 0;
2644 } else
2645 VI_UNLOCK(rootvp);
2646 }
2647 if (busy) {
2648 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
2649 busy);
2650 return (EBUSY);
2651 }
2652 for (; rootrefs > 0; rootrefs--)
2653 vrele(rootvp);
2654 return (0);
2655 }
2656
2657 /*
2658 * Recycle an unused vnode to the front of the free list.
2659 */
2660 int
2661 vrecycle(struct vnode *vp, struct thread *td)
2662 {
2663 int recycled;
2664
2665 ASSERT_VOP_ELOCKED(vp, "vrecycle");
2666 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2667 recycled = 0;
2668 VI_LOCK(vp);
2669 if (vp->v_usecount == 0) {
2670 recycled = 1;
2671 vgonel(vp);
2672 }
2673 VI_UNLOCK(vp);
2674 return (recycled);
2675 }
2676
2677 /*
2678 * Eliminate all activity associated with a vnode
2679 * in preparation for reuse.
2680 */
2681 void
2682 vgone(struct vnode *vp)
2683 {
2684 VI_LOCK(vp);
2685 vgonel(vp);
2686 VI_UNLOCK(vp);
2687 }
2688
2689 /*
2690 * vgone, with the vp interlock held.
2691 */
2692 void
2693 vgonel(struct vnode *vp)
2694 {
2695 struct thread *td;
2696 int oweinact;
2697 int active;
2698 struct mount *mp;
2699
2700 ASSERT_VOP_ELOCKED(vp, "vgonel");
2701 ASSERT_VI_LOCKED(vp, "vgonel");
2702 VNASSERT(vp->v_holdcnt, vp,
2703 ("vgonel: vp %p has no reference.", vp));
2704 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2705 td = curthread;
2706
2707 /*
2708 * Don't vgonel if we're already doomed.
2709 */
2710 if (vp->v_iflag & VI_DOOMED)
2711 return;
2712 vp->v_iflag |= VI_DOOMED;
2713 /*
2714 * Check to see if the vnode is in use. If so, we have to call
2715 * VOP_CLOSE() and VOP_INACTIVE().
2716 */
2717 active = vp->v_usecount;
2718 oweinact = (vp->v_iflag & VI_OWEINACT);
2719 VI_UNLOCK(vp);
2720 /*
2721 * Clean out any buffers associated with the vnode.
2722 * If the flush fails, just toss the buffers.
2723 */
2724 mp = NULL;
2725 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2726 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2727 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0)
2728 vinvalbuf(vp, 0, 0, 0);
2729
2730 /*
2731 * If purging an active vnode, it must be closed and
2732 * deactivated before being reclaimed.
2733 */
2734 if (active)
2735 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2736 if (oweinact || active) {
2737 VI_LOCK(vp);
2738 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2739 vinactive(vp, td);
2740 VI_UNLOCK(vp);
2741 }
2742 if (vp->v_type == VSOCK)
2743 vfs_unp_reclaim(vp);
2744 /*
2745 * Reclaim the vnode.
2746 */
2747 if (VOP_RECLAIM(vp, td))
2748 panic("vgone: cannot reclaim");
2749 if (mp != NULL)
2750 vn_finished_secondary_write(mp);
2751 VNASSERT(vp->v_object == NULL, vp,
2752 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2753 /*
2754 * Clear the advisory locks and wake up waiting threads.
2755 */
2756 (void)VOP_ADVLOCKPURGE(vp);
2757 /*
2758 * Delete from old mount point vnode list.
2759 */
2760 delmntque(vp);
2761 cache_purge(vp);
2762 /*
2763 * Done with purge, reset to the standard lock and invalidate
2764 * the vnode.
2765 */
2766 VI_LOCK(vp);
2767 vp->v_vnlock = &vp->v_lock;
2768 vp->v_op = &dead_vnodeops;
2769 vp->v_tag = "none";
2770 vp->v_type = VBAD;
2771 }
2772
2773 /*
2774 * Calculate the total number of references to a special device.
2775 */
2776 int
2777 vcount(struct vnode *vp)
2778 {
2779 int count;
2780
2781 dev_lock();
2782 count = vp->v_rdev->si_usecount;
2783 dev_unlock();
2784 return (count);
2785 }
2786
2787 /*
2788 * Same as above, but using the struct cdev *as argument
2789 */
2790 int
2791 count_dev(struct cdev *dev)
2792 {
2793 int count;
2794
2795 dev_lock();
2796 count = dev->si_usecount;
2797 dev_unlock();
2798 return(count);
2799 }
2800
2801 /*
2802 * Print out a description of a vnode.
2803 */
2804 static char *typename[] =
2805 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2806 "VMARKER"};
2807
2808 void
2809 vn_printf(struct vnode *vp, const char *fmt, ...)
2810 {
2811 va_list ap;
2812 char buf[256], buf2[16];
2813 u_long flags;
2814
2815 va_start(ap, fmt);
2816 vprintf(fmt, ap);
2817 va_end(ap);
2818 printf("%p: ", (void *)vp);
2819 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2820 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2821 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2822 buf[0] = '\0';
2823 buf[1] = '\0';
2824 if (vp->v_vflag & VV_ROOT)
2825 strlcat(buf, "|VV_ROOT", sizeof(buf));
2826 if (vp->v_vflag & VV_ISTTY)
2827 strlcat(buf, "|VV_ISTTY", sizeof(buf));
2828 if (vp->v_vflag & VV_NOSYNC)
2829 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
2830 if (vp->v_vflag & VV_CACHEDLABEL)
2831 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
2832 if (vp->v_vflag & VV_TEXT)
2833 strlcat(buf, "|VV_TEXT", sizeof(buf));
2834 if (vp->v_vflag & VV_COPYONWRITE)
2835 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
2836 if (vp->v_vflag & VV_SYSTEM)
2837 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
2838 if (vp->v_vflag & VV_PROCDEP)
2839 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
2840 if (vp->v_vflag & VV_NOKNOTE)
2841 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
2842 if (vp->v_vflag & VV_DELETED)
2843 strlcat(buf, "|VV_DELETED", sizeof(buf));
2844 if (vp->v_vflag & VV_MD)
2845 strlcat(buf, "|VV_MD", sizeof(buf));
2846 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC |
2847 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
2848 VV_NOKNOTE | VV_DELETED | VV_MD);
2849 if (flags != 0) {
2850 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
2851 strlcat(buf, buf2, sizeof(buf));
2852 }
2853 if (vp->v_iflag & VI_MOUNT)
2854 strlcat(buf, "|VI_MOUNT", sizeof(buf));
2855 if (vp->v_iflag & VI_AGE)
2856 strlcat(buf, "|VI_AGE", sizeof(buf));
2857 if (vp->v_iflag & VI_DOOMED)
2858 strlcat(buf, "|VI_DOOMED", sizeof(buf));
2859 if (vp->v_iflag & VI_FREE)
2860 strlcat(buf, "|VI_FREE", sizeof(buf));
2861 if (vp->v_iflag & VI_DOINGINACT)
2862 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
2863 if (vp->v_iflag & VI_OWEINACT)
2864 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
2865 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE |
2866 VI_DOINGINACT | VI_OWEINACT);
2867 if (flags != 0) {
2868 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
2869 strlcat(buf, buf2, sizeof(buf));
2870 }
2871 printf(" flags (%s)\n", buf + 1);
2872 if (mtx_owned(VI_MTX(vp)))
2873 printf(" VI_LOCKed");
2874 if (vp->v_object != NULL)
2875 printf(" v_object %p ref %d pages %d\n",
2876 vp->v_object, vp->v_object->ref_count,
2877 vp->v_object->resident_page_count);
2878 printf(" ");
2879 lockmgr_printinfo(vp->v_vnlock);
2880 if (vp->v_data != NULL)
2881 VOP_PRINT(vp);
2882 }
2883
2884 #ifdef DDB
2885 /*
2886 * List all of the locked vnodes in the system.
2887 * Called when debugging the kernel.
2888 */
2889 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2890 {
2891 struct mount *mp, *nmp;
2892 struct vnode *vp;
2893
2894 /*
2895 * Note: because this is DDB, we can't obey the locking semantics
2896 * for these structures, which means we could catch an inconsistent
2897 * state and dereference a nasty pointer. Not much to be done
2898 * about that.
2899 */
2900 db_printf("Locked vnodes\n");
2901 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2902 nmp = TAILQ_NEXT(mp, mnt_list);
2903 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2904 if (vp->v_type != VMARKER &&
2905 VOP_ISLOCKED(vp))
2906 vprint("", vp);
2907 }
2908 nmp = TAILQ_NEXT(mp, mnt_list);
2909 }
2910 }
2911
2912 /*
2913 * Show details about the given vnode.
2914 */
2915 DB_SHOW_COMMAND(vnode, db_show_vnode)
2916 {
2917 struct vnode *vp;
2918
2919 if (!have_addr)
2920 return;
2921 vp = (struct vnode *)addr;
2922 vn_printf(vp, "vnode ");
2923 }
2924
2925 /*
2926 * Show details about the given mount point.
2927 */
2928 DB_SHOW_COMMAND(mount, db_show_mount)
2929 {
2930 struct mount *mp;
2931 struct vfsopt *opt;
2932 struct statfs *sp;
2933 struct vnode *vp;
2934 char buf[512];
2935 uint64_t mflags;
2936 u_int flags;
2937
2938 if (!have_addr) {
2939 /* No address given, print short info about all mount points. */
2940 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2941 db_printf("%p %s on %s (%s)\n", mp,
2942 mp->mnt_stat.f_mntfromname,
2943 mp->mnt_stat.f_mntonname,
2944 mp->mnt_stat.f_fstypename);
2945 if (db_pager_quit)
2946 break;
2947 }
2948 db_printf("\nMore info: show mount <addr>\n");
2949 return;
2950 }
2951
2952 mp = (struct mount *)addr;
2953 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
2954 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
2955
2956 buf[0] = '\0';
2957 mflags = mp->mnt_flag;
2958 #define MNT_FLAG(flag) do { \
2959 if (mflags & (flag)) { \
2960 if (buf[0] != '\0') \
2961 strlcat(buf, ", ", sizeof(buf)); \
2962 strlcat(buf, (#flag) + 4, sizeof(buf)); \
2963 mflags &= ~(flag); \
2964 } \
2965 } while (0)
2966 MNT_FLAG(MNT_RDONLY);
2967 MNT_FLAG(MNT_SYNCHRONOUS);
2968 MNT_FLAG(MNT_NOEXEC);
2969 MNT_FLAG(MNT_NOSUID);
2970 MNT_FLAG(MNT_UNION);
2971 MNT_FLAG(MNT_ASYNC);
2972 MNT_FLAG(MNT_SUIDDIR);
2973 MNT_FLAG(MNT_SOFTDEP);
2974 MNT_FLAG(MNT_SUJ);
2975 MNT_FLAG(MNT_NOSYMFOLLOW);
2976 MNT_FLAG(MNT_GJOURNAL);
2977 MNT_FLAG(MNT_MULTILABEL);
2978 MNT_FLAG(MNT_ACLS);
2979 MNT_FLAG(MNT_NOATIME);
2980 MNT_FLAG(MNT_NOCLUSTERR);
2981 MNT_FLAG(MNT_NOCLUSTERW);
2982 MNT_FLAG(MNT_NFS4ACLS);
2983 MNT_FLAG(MNT_EXRDONLY);
2984 MNT_FLAG(MNT_EXPORTED);
2985 MNT_FLAG(MNT_DEFEXPORTED);
2986 MNT_FLAG(MNT_EXPORTANON);
2987 MNT_FLAG(MNT_EXKERB);
2988 MNT_FLAG(MNT_EXPUBLIC);
2989 MNT_FLAG(MNT_LOCAL);
2990 MNT_FLAG(MNT_QUOTA);
2991 MNT_FLAG(MNT_ROOTFS);
2992 MNT_FLAG(MNT_USER);
2993 MNT_FLAG(MNT_IGNORE);
2994 MNT_FLAG(MNT_UPDATE);
2995 MNT_FLAG(MNT_DELEXPORT);
2996 MNT_FLAG(MNT_RELOAD);
2997 MNT_FLAG(MNT_FORCE);
2998 MNT_FLAG(MNT_SNAPSHOT);
2999 MNT_FLAG(MNT_BYFSID);
3000 #undef MNT_FLAG
3001 if (mflags != 0) {
3002 if (buf[0] != '\0')
3003 strlcat(buf, ", ", sizeof(buf));
3004 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3005 "0x%016jx", mflags);
3006 }
3007 db_printf(" mnt_flag = %s\n", buf);
3008
3009 buf[0] = '\0';
3010 flags = mp->mnt_kern_flag;
3011 #define MNT_KERN_FLAG(flag) do { \
3012 if (flags & (flag)) { \
3013 if (buf[0] != '\0') \
3014 strlcat(buf, ", ", sizeof(buf)); \
3015 strlcat(buf, (#flag) + 5, sizeof(buf)); \
3016 flags &= ~(flag); \
3017 } \
3018 } while (0)
3019 MNT_KERN_FLAG(MNTK_UNMOUNTF);
3020 MNT_KERN_FLAG(MNTK_ASYNC);
3021 MNT_KERN_FLAG(MNTK_SOFTDEP);
3022 MNT_KERN_FLAG(MNTK_NOINSMNTQ);
3023 MNT_KERN_FLAG(MNTK_DRAINING);
3024 MNT_KERN_FLAG(MNTK_REFEXPIRE);
3025 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
3026 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
3027 MNT_KERN_FLAG(MNTK_NOASYNC);
3028 MNT_KERN_FLAG(MNTK_UNMOUNT);
3029 MNT_KERN_FLAG(MNTK_MWAIT);
3030 MNT_KERN_FLAG(MNTK_SUSPEND);
3031 MNT_KERN_FLAG(MNTK_SUSPEND2);
3032 MNT_KERN_FLAG(MNTK_SUSPENDED);
3033 MNT_KERN_FLAG(MNTK_MPSAFE);
3034 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
3035 MNT_KERN_FLAG(MNTK_NOKNOTE);
3036 #undef MNT_KERN_FLAG
3037 if (flags != 0) {
3038 if (buf[0] != '\0')
3039 strlcat(buf, ", ", sizeof(buf));
3040 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3041 "0x%08x", flags);
3042 }
3043 db_printf(" mnt_kern_flag = %s\n", buf);
3044
3045 db_printf(" mnt_opt = ");
3046 opt = TAILQ_FIRST(mp->mnt_opt);
3047 if (opt != NULL) {
3048 db_printf("%s", opt->name);
3049 opt = TAILQ_NEXT(opt, link);
3050 while (opt != NULL) {
3051 db_printf(", %s", opt->name);
3052 opt = TAILQ_NEXT(opt, link);
3053 }
3054 }
3055 db_printf("\n");
3056
3057 sp = &mp->mnt_stat;
3058 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
3059 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
3060 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
3061 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
3062 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
3063 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
3064 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
3065 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
3066 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
3067 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
3068 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
3069 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
3070
3071 db_printf(" mnt_cred = { uid=%u ruid=%u",
3072 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
3073 if (jailed(mp->mnt_cred))
3074 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
3075 db_printf(" }\n");
3076 db_printf(" mnt_ref = %d\n", mp->mnt_ref);
3077 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
3078 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
3079 db_printf(" mnt_activevnodelistsize = %d\n",
3080 mp->mnt_activevnodelistsize);
3081 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
3082 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
3083 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
3084 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
3085 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
3086 db_printf(" mnt_secondary_accwrites = %d\n",
3087 mp->mnt_secondary_accwrites);
3088 db_printf(" mnt_gjprovider = %s\n",
3089 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
3090
3091 db_printf("\n\nList of active vnodes\n");
3092 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
3093 if (vp->v_type != VMARKER) {
3094 vn_printf(vp, "vnode ");
3095 if (db_pager_quit)
3096 break;
3097 }
3098 }
3099 db_printf("\n\nList of inactive vnodes\n");
3100 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3101 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
3102 vn_printf(vp, "vnode ");
3103 if (db_pager_quit)
3104 break;
3105 }
3106 }
3107 }
3108 #endif /* DDB */
3109
3110 /*
3111 * Fill in a struct xvfsconf based on a struct vfsconf.
3112 */
3113 static void
3114 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
3115 {
3116
3117 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
3118 xvfsp->vfc_typenum = vfsp->vfc_typenum;
3119 xvfsp->vfc_refcount = vfsp->vfc_refcount;
3120 xvfsp->vfc_flags = vfsp->vfc_flags;
3121 /*
3122 * These are unused in userland, we keep them
3123 * to not break binary compatibility.
3124 */
3125 xvfsp->vfc_vfsops = NULL;
3126 xvfsp->vfc_next = NULL;
3127 }
3128
3129 /*
3130 * Top level filesystem related information gathering.
3131 */
3132 static int
3133 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
3134 {
3135 struct vfsconf *vfsp;
3136 struct xvfsconf xvfsp;
3137 int error;
3138
3139 error = 0;
3140 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3141 bzero(&xvfsp, sizeof(xvfsp));
3142 vfsconf2x(vfsp, &xvfsp);
3143 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
3144 if (error)
3145 break;
3146 }
3147 return (error);
3148 }
3149
3150 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD,
3151 NULL, 0, sysctl_vfs_conflist,
3152 "S,xvfsconf", "List of all configured filesystems");
3153
3154 #ifndef BURN_BRIDGES
3155 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
3156
3157 static int
3158 vfs_sysctl(SYSCTL_HANDLER_ARGS)
3159 {
3160 int *name = (int *)arg1 - 1; /* XXX */
3161 u_int namelen = arg2 + 1; /* XXX */
3162 struct vfsconf *vfsp;
3163 struct xvfsconf xvfsp;
3164
3165 printf("WARNING: userland calling deprecated sysctl, "
3166 "please rebuild world\n");
3167
3168 #if 1 || defined(COMPAT_PRELITE2)
3169 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
3170 if (namelen == 1)
3171 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
3172 #endif
3173
3174 switch (name[1]) {
3175 case VFS_MAXTYPENUM:
3176 if (namelen != 2)
3177 return (ENOTDIR);
3178 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
3179 case VFS_CONF:
3180 if (namelen != 3)
3181 return (ENOTDIR); /* overloaded */
3182 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
3183 if (vfsp->vfc_typenum == name[2])
3184 break;
3185 if (vfsp == NULL)
3186 return (EOPNOTSUPP);
3187 bzero(&xvfsp, sizeof(xvfsp));
3188 vfsconf2x(vfsp, &xvfsp);
3189 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3190 }
3191 return (EOPNOTSUPP);
3192 }
3193
3194 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
3195 vfs_sysctl, "Generic filesystem");
3196
3197 #if 1 || defined(COMPAT_PRELITE2)
3198
3199 static int
3200 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
3201 {
3202 int error;
3203 struct vfsconf *vfsp;
3204 struct ovfsconf ovfs;
3205
3206 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3207 bzero(&ovfs, sizeof(ovfs));
3208 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
3209 strcpy(ovfs.vfc_name, vfsp->vfc_name);
3210 ovfs.vfc_index = vfsp->vfc_typenum;
3211 ovfs.vfc_refcount = vfsp->vfc_refcount;
3212 ovfs.vfc_flags = vfsp->vfc_flags;
3213 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
3214 if (error)
3215 return error;
3216 }
3217 return 0;
3218 }
3219
3220 #endif /* 1 || COMPAT_PRELITE2 */
3221 #endif /* !BURN_BRIDGES */
3222
3223 #define KINFO_VNODESLOP 10
3224 #ifdef notyet
3225 /*
3226 * Dump vnode list (via sysctl).
3227 */
3228 /* ARGSUSED */
3229 static int
3230 sysctl_vnode(SYSCTL_HANDLER_ARGS)
3231 {
3232 struct xvnode *xvn;
3233 struct mount *mp;
3234 struct vnode *vp;
3235 int error, len, n;
3236
3237 /*
3238 * Stale numvnodes access is not fatal here.
3239 */
3240 req->lock = 0;
3241 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
3242 if (!req->oldptr)
3243 /* Make an estimate */
3244 return (SYSCTL_OUT(req, 0, len));
3245
3246 error = sysctl_wire_old_buffer(req, 0);
3247 if (error != 0)
3248 return (error);
3249 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
3250 n = 0;
3251 mtx_lock(&mountlist_mtx);
3252 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3253 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
3254 continue;
3255 MNT_ILOCK(mp);
3256 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3257 if (n == len)
3258 break;
3259 vref(vp);
3260 xvn[n].xv_size = sizeof *xvn;
3261 xvn[n].xv_vnode = vp;
3262 xvn[n].xv_id = 0; /* XXX compat */
3263 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
3264 XV_COPY(usecount);
3265 XV_COPY(writecount);
3266 XV_COPY(holdcnt);
3267 XV_COPY(mount);
3268 XV_COPY(numoutput);
3269 XV_COPY(type);
3270 #undef XV_COPY
3271 xvn[n].xv_flag = vp->v_vflag;
3272
3273 switch (vp->v_type) {
3274 case VREG:
3275 case VDIR:
3276 case VLNK:
3277 break;
3278 case VBLK:
3279 case VCHR:
3280 if (vp->v_rdev == NULL) {
3281 vrele(vp);
3282 continue;
3283 }
3284 xvn[n].xv_dev = dev2udev(vp->v_rdev);
3285 break;
3286 case VSOCK:
3287 xvn[n].xv_socket = vp->v_socket;
3288 break;
3289 case VFIFO:
3290 xvn[n].xv_fifo = vp->v_fifoinfo;
3291 break;
3292 case VNON:
3293 case VBAD:
3294 default:
3295 /* shouldn't happen? */
3296 vrele(vp);
3297 continue;
3298 }
3299 vrele(vp);
3300 ++n;
3301 }
3302 MNT_IUNLOCK(mp);
3303 mtx_lock(&mountlist_mtx);
3304 vfs_unbusy(mp);
3305 if (n == len)
3306 break;
3307 }
3308 mtx_unlock(&mountlist_mtx);
3309
3310 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
3311 free(xvn, M_TEMP);
3312 return (error);
3313 }
3314
3315 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
3316 0, 0, sysctl_vnode, "S,xvnode", "");
3317 #endif
3318
3319 /*
3320 * Unmount all filesystems. The list is traversed in reverse order
3321 * of mounting to avoid dependencies.
3322 */
3323 void
3324 vfs_unmountall(void)
3325 {
3326 struct mount *mp;
3327 struct thread *td;
3328 int error;
3329
3330 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
3331 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
3332 td = curthread;
3333
3334 /*
3335 * Since this only runs when rebooting, it is not interlocked.
3336 */
3337 while(!TAILQ_EMPTY(&mountlist)) {
3338 mp = TAILQ_LAST(&mountlist, mntlist);
3339 error = dounmount(mp, MNT_FORCE, td);
3340 if (error) {
3341 TAILQ_REMOVE(&mountlist, mp, mnt_list);
3342 /*
3343 * XXX: Due to the way in which we mount the root
3344 * file system off of devfs, devfs will generate a
3345 * "busy" warning when we try to unmount it before
3346 * the root. Don't print a warning as a result in
3347 * order to avoid false positive errors that may
3348 * cause needless upset.
3349 */
3350 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
3351 printf("unmount of %s failed (",
3352 mp->mnt_stat.f_mntonname);
3353 if (error == EBUSY)
3354 printf("BUSY)\n");
3355 else
3356 printf("%d)\n", error);
3357 }
3358 } else {
3359 /* The unmount has removed mp from the mountlist */
3360 }
3361 }
3362 }
3363
3364 /*
3365 * perform msync on all vnodes under a mount point
3366 * the mount point must be locked.
3367 */
3368 void
3369 vfs_msync(struct mount *mp, int flags)
3370 {
3371 struct vnode *vp, *mvp;
3372 struct vm_object *obj;
3373
3374 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
3375 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
3376 obj = vp->v_object;
3377 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
3378 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
3379 if (!vget(vp,
3380 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
3381 curthread)) {
3382 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
3383 vput(vp);
3384 continue;
3385 }
3386
3387 obj = vp->v_object;
3388 if (obj != NULL) {
3389 VM_OBJECT_LOCK(obj);
3390 vm_object_page_clean(obj, 0, 0,
3391 flags == MNT_WAIT ?
3392 OBJPC_SYNC : OBJPC_NOSYNC);
3393 VM_OBJECT_UNLOCK(obj);
3394 }
3395 vput(vp);
3396 }
3397 } else
3398 VI_UNLOCK(vp);
3399 }
3400 }
3401
3402 static void
3403 destroy_vpollinfo(struct vpollinfo *vi)
3404 {
3405 seldrain(&vi->vpi_selinfo);
3406 knlist_destroy(&vi->vpi_selinfo.si_note);
3407 mtx_destroy(&vi->vpi_lock);
3408 uma_zfree(vnodepoll_zone, vi);
3409 }
3410
3411 /*
3412 * Initalize per-vnode helper structure to hold poll-related state.
3413 */
3414 void
3415 v_addpollinfo(struct vnode *vp)
3416 {
3417 struct vpollinfo *vi;
3418
3419 if (vp->v_pollinfo != NULL)
3420 return;
3421 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
3422 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
3423 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
3424 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
3425 VI_LOCK(vp);
3426 if (vp->v_pollinfo != NULL) {
3427 VI_UNLOCK(vp);
3428 destroy_vpollinfo(vi);
3429 return;
3430 }
3431 vp->v_pollinfo = vi;
3432 VI_UNLOCK(vp);
3433 }
3434
3435 /*
3436 * Record a process's interest in events which might happen to
3437 * a vnode. Because poll uses the historic select-style interface
3438 * internally, this routine serves as both the ``check for any
3439 * pending events'' and the ``record my interest in future events''
3440 * functions. (These are done together, while the lock is held,
3441 * to avoid race conditions.)
3442 */
3443 int
3444 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3445 {
3446
3447 v_addpollinfo(vp);
3448 mtx_lock(&vp->v_pollinfo->vpi_lock);
3449 if (vp->v_pollinfo->vpi_revents & events) {
3450 /*
3451 * This leaves events we are not interested
3452 * in available for the other process which
3453 * which presumably had requested them
3454 * (otherwise they would never have been
3455 * recorded).
3456 */
3457 events &= vp->v_pollinfo->vpi_revents;
3458 vp->v_pollinfo->vpi_revents &= ~events;
3459
3460 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3461 return (events);
3462 }
3463 vp->v_pollinfo->vpi_events |= events;
3464 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3465 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3466 return (0);
3467 }
3468
3469 /*
3470 * Routine to create and manage a filesystem syncer vnode.
3471 */
3472 #define sync_close ((int (*)(struct vop_close_args *))nullop)
3473 static int sync_fsync(struct vop_fsync_args *);
3474 static int sync_inactive(struct vop_inactive_args *);
3475 static int sync_reclaim(struct vop_reclaim_args *);
3476
3477 static struct vop_vector sync_vnodeops = {
3478 .vop_bypass = VOP_EOPNOTSUPP,
3479 .vop_close = sync_close, /* close */
3480 .vop_fsync = sync_fsync, /* fsync */
3481 .vop_inactive = sync_inactive, /* inactive */
3482 .vop_reclaim = sync_reclaim, /* reclaim */
3483 .vop_lock1 = vop_stdlock, /* lock */
3484 .vop_unlock = vop_stdunlock, /* unlock */
3485 .vop_islocked = vop_stdislocked, /* islocked */
3486 };
3487
3488 /*
3489 * Create a new filesystem syncer vnode for the specified mount point.
3490 */
3491 void
3492 vfs_allocate_syncvnode(struct mount *mp)
3493 {
3494 struct vnode *vp;
3495 struct bufobj *bo;
3496 static long start, incr, next;
3497 int error;
3498
3499 /* Allocate a new vnode */
3500 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
3501 if (error != 0)
3502 panic("vfs_allocate_syncvnode: getnewvnode() failed");
3503 vp->v_type = VNON;
3504 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3505 vp->v_vflag |= VV_FORCEINSMQ;
3506 error = insmntque(vp, mp);
3507 if (error != 0)
3508 panic("vfs_allocate_syncvnode: insmntque() failed");
3509 vp->v_vflag &= ~VV_FORCEINSMQ;
3510 VOP_UNLOCK(vp, 0);
3511 /*
3512 * Place the vnode onto the syncer worklist. We attempt to
3513 * scatter them about on the list so that they will go off
3514 * at evenly distributed times even if all the filesystems
3515 * are mounted at once.
3516 */
3517 next += incr;
3518 if (next == 0 || next > syncer_maxdelay) {
3519 start /= 2;
3520 incr /= 2;
3521 if (start == 0) {
3522 start = syncer_maxdelay / 2;
3523 incr = syncer_maxdelay;
3524 }
3525 next = start;
3526 }
3527 bo = &vp->v_bufobj;
3528 BO_LOCK(bo);
3529 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
3530 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
3531 mtx_lock(&sync_mtx);
3532 sync_vnode_count++;
3533 if (mp->mnt_syncer == NULL) {
3534 mp->mnt_syncer = vp;
3535 vp = NULL;
3536 }
3537 mtx_unlock(&sync_mtx);
3538 BO_UNLOCK(bo);
3539 if (vp != NULL) {
3540 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3541 vgone(vp);
3542 vput(vp);
3543 }
3544 }
3545
3546 void
3547 vfs_deallocate_syncvnode(struct mount *mp)
3548 {
3549 struct vnode *vp;
3550
3551 mtx_lock(&sync_mtx);
3552 vp = mp->mnt_syncer;
3553 if (vp != NULL)
3554 mp->mnt_syncer = NULL;
3555 mtx_unlock(&sync_mtx);
3556 if (vp != NULL)
3557 vrele(vp);
3558 }
3559
3560 /*
3561 * Do a lazy sync of the filesystem.
3562 */
3563 static int
3564 sync_fsync(struct vop_fsync_args *ap)
3565 {
3566 struct vnode *syncvp = ap->a_vp;
3567 struct mount *mp = syncvp->v_mount;
3568 int error, save;
3569 struct bufobj *bo;
3570
3571 /*
3572 * We only need to do something if this is a lazy evaluation.
3573 */
3574 if (ap->a_waitfor != MNT_LAZY)
3575 return (0);
3576
3577 /*
3578 * Move ourselves to the back of the sync list.
3579 */
3580 bo = &syncvp->v_bufobj;
3581 BO_LOCK(bo);
3582 vn_syncer_add_to_worklist(bo, syncdelay);
3583 BO_UNLOCK(bo);
3584
3585 /*
3586 * Walk the list of vnodes pushing all that are dirty and
3587 * not already on the sync list.
3588 */
3589 mtx_lock(&mountlist_mtx);
3590 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
3591 mtx_unlock(&mountlist_mtx);
3592 return (0);
3593 }
3594 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
3595 vfs_unbusy(mp);
3596 return (0);
3597 }
3598 save = curthread_pflags_set(TDP_SYNCIO);
3599 vfs_msync(mp, MNT_NOWAIT);
3600 error = VFS_SYNC(mp, MNT_LAZY);
3601 curthread_pflags_restore(save);
3602 vn_finished_write(mp);
3603 vfs_unbusy(mp);
3604 return (error);
3605 }
3606
3607 /*
3608 * The syncer vnode is no referenced.
3609 */
3610 static int
3611 sync_inactive(struct vop_inactive_args *ap)
3612 {
3613
3614 vgone(ap->a_vp);
3615 return (0);
3616 }
3617
3618 /*
3619 * The syncer vnode is no longer needed and is being decommissioned.
3620 *
3621 * Modifications to the worklist must be protected by sync_mtx.
3622 */
3623 static int
3624 sync_reclaim(struct vop_reclaim_args *ap)
3625 {
3626 struct vnode *vp = ap->a_vp;
3627 struct bufobj *bo;
3628
3629 bo = &vp->v_bufobj;
3630 BO_LOCK(bo);
3631 mtx_lock(&sync_mtx);
3632 if (vp->v_mount->mnt_syncer == vp)
3633 vp->v_mount->mnt_syncer = NULL;
3634 if (bo->bo_flag & BO_ONWORKLST) {
3635 LIST_REMOVE(bo, bo_synclist);
3636 syncer_worklist_len--;
3637 sync_vnode_count--;
3638 bo->bo_flag &= ~BO_ONWORKLST;
3639 }
3640 mtx_unlock(&sync_mtx);
3641 BO_UNLOCK(bo);
3642
3643 return (0);
3644 }
3645
3646 /*
3647 * Check if vnode represents a disk device
3648 */
3649 int
3650 vn_isdisk(struct vnode *vp, int *errp)
3651 {
3652 int error;
3653
3654 error = 0;
3655 dev_lock();
3656 if (vp->v_type != VCHR)
3657 error = ENOTBLK;
3658 else if (vp->v_rdev == NULL)
3659 error = ENXIO;
3660 else if (vp->v_rdev->si_devsw == NULL)
3661 error = ENXIO;
3662 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
3663 error = ENOTBLK;
3664 dev_unlock();
3665 if (errp != NULL)
3666 *errp = error;
3667 return (error == 0);
3668 }
3669
3670 /*
3671 * Common filesystem object access control check routine. Accepts a
3672 * vnode's type, "mode", uid and gid, requested access mode, credentials,
3673 * and optional call-by-reference privused argument allowing vaccess()
3674 * to indicate to the caller whether privilege was used to satisfy the
3675 * request (obsoleted). Returns 0 on success, or an errno on failure.
3676 */
3677 int
3678 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
3679 accmode_t accmode, struct ucred *cred, int *privused)
3680 {
3681 accmode_t dac_granted;
3682 accmode_t priv_granted;
3683
3684 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
3685 ("invalid bit in accmode"));
3686 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
3687 ("VAPPEND without VWRITE"));
3688
3689 /*
3690 * Look for a normal, non-privileged way to access the file/directory
3691 * as requested. If it exists, go with that.
3692 */
3693
3694 if (privused != NULL)
3695 *privused = 0;
3696
3697 dac_granted = 0;
3698
3699 /* Check the owner. */
3700 if (cred->cr_uid == file_uid) {
3701 dac_granted |= VADMIN;
3702 if (file_mode & S_IXUSR)
3703 dac_granted |= VEXEC;
3704 if (file_mode & S_IRUSR)
3705 dac_granted |= VREAD;
3706 if (file_mode & S_IWUSR)
3707 dac_granted |= (VWRITE | VAPPEND);
3708
3709 if ((accmode & dac_granted) == accmode)
3710 return (0);
3711
3712 goto privcheck;
3713 }
3714
3715 /* Otherwise, check the groups (first match) */
3716 if (groupmember(file_gid, cred)) {
3717 if (file_mode & S_IXGRP)
3718 dac_granted |= VEXEC;
3719 if (file_mode & S_IRGRP)
3720 dac_granted |= VREAD;
3721 if (file_mode & S_IWGRP)
3722 dac_granted |= (VWRITE | VAPPEND);
3723
3724 if ((accmode & dac_granted) == accmode)
3725 return (0);
3726
3727 goto privcheck;
3728 }
3729
3730 /* Otherwise, check everyone else. */
3731 if (file_mode & S_IXOTH)
3732 dac_granted |= VEXEC;
3733 if (file_mode & S_IROTH)
3734 dac_granted |= VREAD;
3735 if (file_mode & S_IWOTH)
3736 dac_granted |= (VWRITE | VAPPEND);
3737 if ((accmode & dac_granted) == accmode)
3738 return (0);
3739
3740 privcheck:
3741 /*
3742 * Build a privilege mask to determine if the set of privileges
3743 * satisfies the requirements when combined with the granted mask
3744 * from above. For each privilege, if the privilege is required,
3745 * bitwise or the request type onto the priv_granted mask.
3746 */
3747 priv_granted = 0;
3748
3749 if (type == VDIR) {
3750 /*
3751 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
3752 * requests, instead of PRIV_VFS_EXEC.
3753 */
3754 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3755 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
3756 priv_granted |= VEXEC;
3757 } else {
3758 /*
3759 * Ensure that at least one execute bit is on. Otherwise,
3760 * a privileged user will always succeed, and we don't want
3761 * this to happen unless the file really is executable.
3762 */
3763 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3764 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
3765 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
3766 priv_granted |= VEXEC;
3767 }
3768
3769 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
3770 !priv_check_cred(cred, PRIV_VFS_READ, 0))
3771 priv_granted |= VREAD;
3772
3773 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
3774 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
3775 priv_granted |= (VWRITE | VAPPEND);
3776
3777 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
3778 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
3779 priv_granted |= VADMIN;
3780
3781 if ((accmode & (priv_granted | dac_granted)) == accmode) {
3782 /* XXX audit: privilege used */
3783 if (privused != NULL)
3784 *privused = 1;
3785 return (0);
3786 }
3787
3788 return ((accmode & VADMIN) ? EPERM : EACCES);
3789 }
3790
3791 /*
3792 * Credential check based on process requesting service, and per-attribute
3793 * permissions.
3794 */
3795 int
3796 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
3797 struct thread *td, accmode_t accmode)
3798 {
3799
3800 /*
3801 * Kernel-invoked always succeeds.
3802 */
3803 if (cred == NOCRED)
3804 return (0);
3805
3806 /*
3807 * Do not allow privileged processes in jail to directly manipulate
3808 * system attributes.
3809 */
3810 switch (attrnamespace) {
3811 case EXTATTR_NAMESPACE_SYSTEM:
3812 /* Potentially should be: return (EPERM); */
3813 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
3814 case EXTATTR_NAMESPACE_USER:
3815 return (VOP_ACCESS(vp, accmode, cred, td));
3816 default:
3817 return (EPERM);
3818 }
3819 }
3820
3821 #ifdef DEBUG_VFS_LOCKS
3822 /*
3823 * This only exists to supress warnings from unlocked specfs accesses. It is
3824 * no longer ok to have an unlocked VFS.
3825 */
3826 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
3827 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
3828
3829 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
3830 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
3831 "Drop into debugger on lock violation");
3832
3833 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
3834 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
3835 0, "Check for interlock across VOPs");
3836
3837 int vfs_badlock_print = 1; /* Print lock violations. */
3838 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
3839 0, "Print lock violations");
3840
3841 #ifdef KDB
3842 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
3843 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
3844 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
3845 #endif
3846
3847 static void
3848 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
3849 {
3850
3851 #ifdef KDB
3852 if (vfs_badlock_backtrace)
3853 kdb_backtrace();
3854 #endif
3855 if (vfs_badlock_print)
3856 printf("%s: %p %s\n", str, (void *)vp, msg);
3857 if (vfs_badlock_ddb)
3858 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
3859 }
3860
3861 void
3862 assert_vi_locked(struct vnode *vp, const char *str)
3863 {
3864
3865 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
3866 vfs_badlock("interlock is not locked but should be", str, vp);
3867 }
3868
3869 void
3870 assert_vi_unlocked(struct vnode *vp, const char *str)
3871 {
3872
3873 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
3874 vfs_badlock("interlock is locked but should not be", str, vp);
3875 }
3876
3877 void
3878 assert_vop_locked(struct vnode *vp, const char *str)
3879 {
3880
3881 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == 0)
3882 vfs_badlock("is not locked but should be", str, vp);
3883 }
3884
3885 void
3886 assert_vop_unlocked(struct vnode *vp, const char *str)
3887 {
3888
3889 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
3890 vfs_badlock("is locked but should not be", str, vp);
3891 }
3892
3893 void
3894 assert_vop_elocked(struct vnode *vp, const char *str)
3895 {
3896
3897 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
3898 vfs_badlock("is not exclusive locked but should be", str, vp);
3899 }
3900
3901 #if 0
3902 void
3903 assert_vop_elocked_other(struct vnode *vp, const char *str)
3904 {
3905
3906 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER)
3907 vfs_badlock("is not exclusive locked by another thread",
3908 str, vp);
3909 }
3910
3911 void
3912 assert_vop_slocked(struct vnode *vp, const char *str)
3913 {
3914
3915 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED)
3916 vfs_badlock("is not locked shared but should be", str, vp);
3917 }
3918 #endif /* 0 */
3919 #endif /* DEBUG_VFS_LOCKS */
3920
3921 void
3922 vop_rename_fail(struct vop_rename_args *ap)
3923 {
3924
3925 if (ap->a_tvp != NULL)
3926 vput(ap->a_tvp);
3927 if (ap->a_tdvp == ap->a_tvp)
3928 vrele(ap->a_tdvp);
3929 else
3930 vput(ap->a_tdvp);
3931 vrele(ap->a_fdvp);
3932 vrele(ap->a_fvp);
3933 }
3934
3935 void
3936 vop_rename_pre(void *ap)
3937 {
3938 struct vop_rename_args *a = ap;
3939
3940 #ifdef DEBUG_VFS_LOCKS
3941 if (a->a_tvp)
3942 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
3943 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
3944 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
3945 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
3946
3947 /* Check the source (from). */
3948 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
3949 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
3950 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
3951 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
3952 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
3953
3954 /* Check the target. */
3955 if (a->a_tvp)
3956 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
3957 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
3958 #endif
3959 if (a->a_tdvp != a->a_fdvp)
3960 vhold(a->a_fdvp);
3961 if (a->a_tvp != a->a_fvp)
3962 vhold(a->a_fvp);
3963 vhold(a->a_tdvp);
3964 if (a->a_tvp)
3965 vhold(a->a_tvp);
3966 }
3967
3968 void
3969 vop_strategy_pre(void *ap)
3970 {
3971 #ifdef DEBUG_VFS_LOCKS
3972 struct vop_strategy_args *a;
3973 struct buf *bp;
3974
3975 a = ap;
3976 bp = a->a_bp;
3977
3978 /*
3979 * Cluster ops lock their component buffers but not the IO container.
3980 */
3981 if ((bp->b_flags & B_CLUSTER) != 0)
3982 return;
3983
3984 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
3985 if (vfs_badlock_print)
3986 printf(
3987 "VOP_STRATEGY: bp is not locked but should be\n");
3988 if (vfs_badlock_ddb)
3989 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
3990 }
3991 #endif
3992 }
3993
3994 void
3995 vop_lookup_pre(void *ap)
3996 {
3997 #ifdef DEBUG_VFS_LOCKS
3998 struct vop_lookup_args *a;
3999 struct vnode *dvp;
4000
4001 a = ap;
4002 dvp = a->a_dvp;
4003 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
4004 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
4005 #endif
4006 }
4007
4008 void
4009 vop_lookup_post(void *ap, int rc)
4010 {
4011 #ifdef DEBUG_VFS_LOCKS
4012 struct vop_lookup_args *a;
4013 struct vnode *dvp;
4014 struct vnode *vp;
4015
4016 a = ap;
4017 dvp = a->a_dvp;
4018 vp = *(a->a_vpp);
4019
4020 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
4021 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
4022
4023 if (!rc)
4024 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)");
4025 #endif
4026 }
4027
4028 void
4029 vop_lock_pre(void *ap)
4030 {
4031 #ifdef DEBUG_VFS_LOCKS
4032 struct vop_lock1_args *a = ap;
4033
4034 if ((a->a_flags & LK_INTERLOCK) == 0)
4035 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4036 else
4037 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
4038 #endif
4039 }
4040
4041 void
4042 vop_lock_post(void *ap, int rc)
4043 {
4044 #ifdef DEBUG_VFS_LOCKS
4045 struct vop_lock1_args *a = ap;
4046
4047 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4048 if (rc == 0)
4049 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
4050 #endif
4051 }
4052
4053 void
4054 vop_unlock_pre(void *ap)
4055 {
4056 #ifdef DEBUG_VFS_LOCKS
4057 struct vop_unlock_args *a = ap;
4058
4059 if (a->a_flags & LK_INTERLOCK)
4060 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
4061 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
4062 #endif
4063 }
4064
4065 void
4066 vop_unlock_post(void *ap, int rc)
4067 {
4068 #ifdef DEBUG_VFS_LOCKS
4069 struct vop_unlock_args *a = ap;
4070
4071 if (a->a_flags & LK_INTERLOCK)
4072 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
4073 #endif
4074 }
4075
4076 void
4077 vop_create_post(void *ap, int rc)
4078 {
4079 struct vop_create_args *a = ap;
4080
4081 if (!rc)
4082 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4083 }
4084
4085 void
4086 vop_deleteextattr_post(void *ap, int rc)
4087 {
4088 struct vop_deleteextattr_args *a = ap;
4089
4090 if (!rc)
4091 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4092 }
4093
4094 void
4095 vop_link_post(void *ap, int rc)
4096 {
4097 struct vop_link_args *a = ap;
4098
4099 if (!rc) {
4100 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
4101 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
4102 }
4103 }
4104
4105 void
4106 vop_mkdir_post(void *ap, int rc)
4107 {
4108 struct vop_mkdir_args *a = ap;
4109
4110 if (!rc)
4111 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4112 }
4113
4114 void
4115 vop_mknod_post(void *ap, int rc)
4116 {
4117 struct vop_mknod_args *a = ap;
4118
4119 if (!rc)
4120 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4121 }
4122
4123 void
4124 vop_remove_post(void *ap, int rc)
4125 {
4126 struct vop_remove_args *a = ap;
4127
4128 if (!rc) {
4129 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4130 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4131 }
4132 }
4133
4134 void
4135 vop_rename_post(void *ap, int rc)
4136 {
4137 struct vop_rename_args *a = ap;
4138
4139 if (!rc) {
4140 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE);
4141 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE);
4142 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
4143 if (a->a_tvp)
4144 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
4145 }
4146 if (a->a_tdvp != a->a_fdvp)
4147 vdrop(a->a_fdvp);
4148 if (a->a_tvp != a->a_fvp)
4149 vdrop(a->a_fvp);
4150 vdrop(a->a_tdvp);
4151 if (a->a_tvp)
4152 vdrop(a->a_tvp);
4153 }
4154
4155 void
4156 vop_rmdir_post(void *ap, int rc)
4157 {
4158 struct vop_rmdir_args *a = ap;
4159
4160 if (!rc) {
4161 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4162 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4163 }
4164 }
4165
4166 void
4167 vop_setattr_post(void *ap, int rc)
4168 {
4169 struct vop_setattr_args *a = ap;
4170
4171 if (!rc)
4172 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4173 }
4174
4175 void
4176 vop_setextattr_post(void *ap, int rc)
4177 {
4178 struct vop_setextattr_args *a = ap;
4179
4180 if (!rc)
4181 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4182 }
4183
4184 void
4185 vop_symlink_post(void *ap, int rc)
4186 {
4187 struct vop_symlink_args *a = ap;
4188
4189 if (!rc)
4190 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4191 }
4192
4193 static struct knlist fs_knlist;
4194
4195 static void
4196 vfs_event_init(void *arg)
4197 {
4198 knlist_init_mtx(&fs_knlist, NULL);
4199 }
4200 /* XXX - correct order? */
4201 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
4202
4203 void
4204 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
4205 {
4206
4207 KNOTE_UNLOCKED(&fs_knlist, event);
4208 }
4209
4210 static int filt_fsattach(struct knote *kn);
4211 static void filt_fsdetach(struct knote *kn);
4212 static int filt_fsevent(struct knote *kn, long hint);
4213
4214 struct filterops fs_filtops = {
4215 .f_isfd = 0,
4216 .f_attach = filt_fsattach,
4217 .f_detach = filt_fsdetach,
4218 .f_event = filt_fsevent
4219 };
4220
4221 static int
4222 filt_fsattach(struct knote *kn)
4223 {
4224
4225 kn->kn_flags |= EV_CLEAR;
4226 knlist_add(&fs_knlist, kn, 0);
4227 return (0);
4228 }
4229
4230 static void
4231 filt_fsdetach(struct knote *kn)
4232 {
4233
4234 knlist_remove(&fs_knlist, kn, 0);
4235 }
4236
4237 static int
4238 filt_fsevent(struct knote *kn, long hint)
4239 {
4240
4241 kn->kn_fflags |= hint;
4242 return (kn->kn_fflags != 0);
4243 }
4244
4245 static int
4246 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
4247 {
4248 struct vfsidctl vc;
4249 int error;
4250 struct mount *mp;
4251
4252 error = SYSCTL_IN(req, &vc, sizeof(vc));
4253 if (error)
4254 return (error);
4255 if (vc.vc_vers != VFS_CTL_VERS1)
4256 return (EINVAL);
4257 mp = vfs_getvfs(&vc.vc_fsid);
4258 if (mp == NULL)
4259 return (ENOENT);
4260 /* ensure that a specific sysctl goes to the right filesystem. */
4261 if (strcmp(vc.vc_fstypename, "*") != 0 &&
4262 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
4263 vfs_rel(mp);
4264 return (EINVAL);
4265 }
4266 VCTLTOREQ(&vc, req);
4267 error = VFS_SYSCTL(mp, vc.vc_op, req);
4268 vfs_rel(mp);
4269 return (error);
4270 }
4271
4272 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
4273 NULL, 0, sysctl_vfs_ctl, "",
4274 "Sysctl by fsid");
4275
4276 /*
4277 * Function to initialize a va_filerev field sensibly.
4278 * XXX: Wouldn't a random number make a lot more sense ??
4279 */
4280 u_quad_t
4281 init_va_filerev(void)
4282 {
4283 struct bintime bt;
4284
4285 getbinuptime(&bt);
4286 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
4287 }
4288
4289 static int filt_vfsread(struct knote *kn, long hint);
4290 static int filt_vfswrite(struct knote *kn, long hint);
4291 static int filt_vfsvnode(struct knote *kn, long hint);
4292 static void filt_vfsdetach(struct knote *kn);
4293 static struct filterops vfsread_filtops = {
4294 .f_isfd = 1,
4295 .f_detach = filt_vfsdetach,
4296 .f_event = filt_vfsread
4297 };
4298 static struct filterops vfswrite_filtops = {
4299 .f_isfd = 1,
4300 .f_detach = filt_vfsdetach,
4301 .f_event = filt_vfswrite
4302 };
4303 static struct filterops vfsvnode_filtops = {
4304 .f_isfd = 1,
4305 .f_detach = filt_vfsdetach,
4306 .f_event = filt_vfsvnode
4307 };
4308
4309 static void
4310 vfs_knllock(void *arg)
4311 {
4312 struct vnode *vp = arg;
4313
4314 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4315 }
4316
4317 static void
4318 vfs_knlunlock(void *arg)
4319 {
4320 struct vnode *vp = arg;
4321
4322 VOP_UNLOCK(vp, 0);
4323 }
4324
4325 static void
4326 vfs_knl_assert_locked(void *arg)
4327 {
4328 #ifdef DEBUG_VFS_LOCKS
4329 struct vnode *vp = arg;
4330
4331 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
4332 #endif
4333 }
4334
4335 static void
4336 vfs_knl_assert_unlocked(void *arg)
4337 {
4338 #ifdef DEBUG_VFS_LOCKS
4339 struct vnode *vp = arg;
4340
4341 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
4342 #endif
4343 }
4344
4345 int
4346 vfs_kqfilter(struct vop_kqfilter_args *ap)
4347 {
4348 struct vnode *vp = ap->a_vp;
4349 struct knote *kn = ap->a_kn;
4350 struct knlist *knl;
4351
4352 switch (kn->kn_filter) {
4353 case EVFILT_READ:
4354 kn->kn_fop = &vfsread_filtops;
4355 break;
4356 case EVFILT_WRITE:
4357 kn->kn_fop = &vfswrite_filtops;
4358 break;
4359 case EVFILT_VNODE:
4360 kn->kn_fop = &vfsvnode_filtops;
4361 break;
4362 default:
4363 return (EINVAL);
4364 }
4365
4366 kn->kn_hook = (caddr_t)vp;
4367
4368 v_addpollinfo(vp);
4369 if (vp->v_pollinfo == NULL)
4370 return (ENOMEM);
4371 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
4372 knlist_add(knl, kn, 0);
4373
4374 return (0);
4375 }
4376
4377 /*
4378 * Detach knote from vnode
4379 */
4380 static void
4381 filt_vfsdetach(struct knote *kn)
4382 {
4383 struct vnode *vp = (struct vnode *)kn->kn_hook;
4384
4385 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
4386 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
4387 }
4388
4389 /*ARGSUSED*/
4390 static int
4391 filt_vfsread(struct knote *kn, long hint)
4392 {
4393 struct vnode *vp = (struct vnode *)kn->kn_hook;
4394 struct vattr va;
4395 int res;
4396
4397 /*
4398 * filesystem is gone, so set the EOF flag and schedule
4399 * the knote for deletion.
4400 */
4401 if (hint == NOTE_REVOKE) {
4402 VI_LOCK(vp);
4403 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4404 VI_UNLOCK(vp);
4405 return (1);
4406 }
4407
4408 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
4409 return (0);
4410
4411 VI_LOCK(vp);
4412 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
4413 res = (kn->kn_data != 0);
4414 VI_UNLOCK(vp);
4415 return (res);
4416 }
4417
4418 /*ARGSUSED*/
4419 static int
4420 filt_vfswrite(struct knote *kn, long hint)
4421 {
4422 struct vnode *vp = (struct vnode *)kn->kn_hook;
4423
4424 VI_LOCK(vp);
4425
4426 /*
4427 * filesystem is gone, so set the EOF flag and schedule
4428 * the knote for deletion.
4429 */
4430 if (hint == NOTE_REVOKE)
4431 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4432
4433 kn->kn_data = 0;
4434 VI_UNLOCK(vp);
4435 return (1);
4436 }
4437
4438 static int
4439 filt_vfsvnode(struct knote *kn, long hint)
4440 {
4441 struct vnode *vp = (struct vnode *)kn->kn_hook;
4442 int res;
4443
4444 VI_LOCK(vp);
4445 if (kn->kn_sfflags & hint)
4446 kn->kn_fflags |= hint;
4447 if (hint == NOTE_REVOKE) {
4448 kn->kn_flags |= EV_EOF;
4449 VI_UNLOCK(vp);
4450 return (1);
4451 }
4452 res = (kn->kn_fflags != 0);
4453 VI_UNLOCK(vp);
4454 return (res);
4455 }
4456
4457 int
4458 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
4459 {
4460 int error;
4461
4462 if (dp->d_reclen > ap->a_uio->uio_resid)
4463 return (ENAMETOOLONG);
4464 error = uiomove(dp, dp->d_reclen, ap->a_uio);
4465 if (error) {
4466 if (ap->a_ncookies != NULL) {
4467 if (ap->a_cookies != NULL)
4468 free(ap->a_cookies, M_TEMP);
4469 ap->a_cookies = NULL;
4470 *ap->a_ncookies = 0;
4471 }
4472 return (error);
4473 }
4474 if (ap->a_ncookies == NULL)
4475 return (0);
4476
4477 KASSERT(ap->a_cookies,
4478 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
4479
4480 *ap->a_cookies = realloc(*ap->a_cookies,
4481 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
4482 (*ap->a_cookies)[*ap->a_ncookies] = off;
4483 return (0);
4484 }
4485
4486 /*
4487 * Mark for update the access time of the file if the filesystem
4488 * supports VOP_MARKATIME. This functionality is used by execve and
4489 * mmap, so we want to avoid the I/O implied by directly setting
4490 * va_atime for the sake of efficiency.
4491 */
4492 void
4493 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
4494 {
4495 struct mount *mp;
4496
4497 mp = vp->v_mount;
4498 VFS_ASSERT_GIANT(mp);
4499 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
4500 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
4501 (void)VOP_MARKATIME(vp);
4502 }
4503
4504 /*
4505 * The purpose of this routine is to remove granularity from accmode_t,
4506 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
4507 * VADMIN and VAPPEND.
4508 *
4509 * If it returns 0, the caller is supposed to continue with the usual
4510 * access checks using 'accmode' as modified by this routine. If it
4511 * returns nonzero value, the caller is supposed to return that value
4512 * as errno.
4513 *
4514 * Note that after this routine runs, accmode may be zero.
4515 */
4516 int
4517 vfs_unixify_accmode(accmode_t *accmode)
4518 {
4519 /*
4520 * There is no way to specify explicit "deny" rule using
4521 * file mode or POSIX.1e ACLs.
4522 */
4523 if (*accmode & VEXPLICIT_DENY) {
4524 *accmode = 0;
4525 return (0);
4526 }
4527
4528 /*
4529 * None of these can be translated into usual access bits.
4530 * Also, the common case for NFSv4 ACLs is to not contain
4531 * either of these bits. Caller should check for VWRITE
4532 * on the containing directory instead.
4533 */
4534 if (*accmode & (VDELETE_CHILD | VDELETE))
4535 return (EPERM);
4536
4537 if (*accmode & VADMIN_PERMS) {
4538 *accmode &= ~VADMIN_PERMS;
4539 *accmode |= VADMIN;
4540 }
4541
4542 /*
4543 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
4544 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
4545 */
4546 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
4547
4548 return (0);
4549 }
4550
4551 /*
4552 * These are helper functions for filesystems to traverse all
4553 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
4554 *
4555 * This interface replaces MNT_VNODE_FOREACH.
4556 */
4557
4558 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
4559
4560 struct vnode *
4561 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
4562 {
4563 struct vnode *vp;
4564
4565 if (should_yield())
4566 kern_yield(PRI_UNCHANGED);
4567 MNT_ILOCK(mp);
4568 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4569 vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
4570 while (vp != NULL && (vp->v_type == VMARKER ||
4571 (vp->v_iflag & VI_DOOMED) != 0))
4572 vp = TAILQ_NEXT(vp, v_nmntvnodes);
4573
4574 /* Check if we are done */
4575 if (vp == NULL) {
4576 __mnt_vnode_markerfree_all(mvp, mp);
4577 /* MNT_IUNLOCK(mp); -- done in above function */
4578 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
4579 return (NULL);
4580 }
4581 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
4582 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
4583 VI_LOCK(vp);
4584 MNT_IUNLOCK(mp);
4585 return (vp);
4586 }
4587
4588 struct vnode *
4589 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
4590 {
4591 struct vnode *vp;
4592
4593 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
4594 MNT_ILOCK(mp);
4595 MNT_REF(mp);
4596 (*mvp)->v_type = VMARKER;
4597
4598 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
4599 while (vp != NULL && (vp->v_type == VMARKER ||
4600 (vp->v_iflag & VI_DOOMED) != 0))
4601 vp = TAILQ_NEXT(vp, v_nmntvnodes);
4602
4603 /* Check if we are done */
4604 if (vp == NULL) {
4605 MNT_REL(mp);
4606 MNT_IUNLOCK(mp);
4607 free(*mvp, M_VNODE_MARKER);
4608 *mvp = NULL;
4609 return (NULL);
4610 }
4611 (*mvp)->v_mount = mp;
4612 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
4613 VI_LOCK(vp);
4614 MNT_IUNLOCK(mp);
4615 return (vp);
4616 }
4617
4618
4619 void
4620 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
4621 {
4622
4623 if (*mvp == NULL) {
4624 MNT_IUNLOCK(mp);
4625 return;
4626 }
4627
4628 mtx_assert(MNT_MTX(mp), MA_OWNED);
4629
4630 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4631 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
4632 MNT_REL(mp);
4633 MNT_IUNLOCK(mp);
4634 free(*mvp, M_VNODE_MARKER);
4635 *mvp = NULL;
4636 }
4637
4638 /*
4639 * These are helper functions for filesystems to traverse their
4640 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
4641 */
4642 struct vnode *
4643 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
4644 {
4645 struct vnode *vp, *nvp;
4646
4647 if (should_yield())
4648 kern_yield(PRI_UNCHANGED);
4649 MNT_ILOCK(mp);
4650 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4651 vp = TAILQ_NEXT(*mvp, v_actfreelist);
4652 while (vp != NULL) {
4653 VI_LOCK(vp);
4654 if (vp->v_mount == mp && vp->v_type != VMARKER &&
4655 (vp->v_iflag & VI_DOOMED) == 0)
4656 break;
4657 nvp = TAILQ_NEXT(vp, v_actfreelist);
4658 VI_UNLOCK(vp);
4659 vp = nvp;
4660 }
4661
4662 /* Check if we are done */
4663 if (vp == NULL) {
4664 __mnt_vnode_markerfree_active(mvp, mp);
4665 /* MNT_IUNLOCK(mp); -- done in above function */
4666 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
4667 return (NULL);
4668 }
4669 mtx_lock(&vnode_free_list_mtx);
4670 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
4671 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
4672 mtx_unlock(&vnode_free_list_mtx);
4673 MNT_IUNLOCK(mp);
4674 return (vp);
4675 }
4676
4677 struct vnode *
4678 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
4679 {
4680 struct vnode *vp, *nvp;
4681
4682 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
4683 MNT_ILOCK(mp);
4684 MNT_REF(mp);
4685 (*mvp)->v_type = VMARKER;
4686
4687 vp = TAILQ_NEXT(*mvp, v_actfreelist);
4688 while (vp != NULL) {
4689 VI_LOCK(vp);
4690 if (vp->v_mount == mp && vp->v_type != VMARKER &&
4691 (vp->v_iflag & VI_DOOMED) == 0)
4692 break;
4693 nvp = TAILQ_NEXT(vp, v_actfreelist);
4694 VI_UNLOCK(vp);
4695 vp = nvp;
4696 }
4697
4698 /* Check if we are done */
4699 if (vp == NULL) {
4700 MNT_REL(mp);
4701 MNT_IUNLOCK(mp);
4702 free(*mvp, M_VNODE_MARKER);
4703 *mvp = NULL;
4704 return (NULL);
4705 }
4706 (*mvp)->v_mount = mp;
4707 mtx_lock(&vnode_free_list_mtx);
4708 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
4709 mtx_unlock(&vnode_free_list_mtx);
4710 MNT_IUNLOCK(mp);
4711 return (vp);
4712 }
4713
4714 void
4715 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
4716 {
4717
4718 if (*mvp == NULL) {
4719 MNT_IUNLOCK(mp);
4720 return;
4721 }
4722
4723 mtx_assert(MNT_MTX(mp), MA_OWNED);
4724
4725 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4726 mtx_lock(&vnode_free_list_mtx);
4727 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
4728 mtx_unlock(&vnode_free_list_mtx);
4729 MNT_REL(mp);
4730 MNT_IUNLOCK(mp);
4731 free(*mvp, M_VNODE_MARKER);
4732 *mvp = NULL;
4733 }
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