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/10.0/sys/kern/vfs_subr.c 256211 2013-10-09 18:43:29Z kib $");
43
44 #include "opt_compat.h"
45 #include "opt_ddb.h"
46 #include "opt_watchdog.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/bio.h>
51 #include <sys/buf.h>
52 #include <sys/condvar.h>
53 #include <sys/conf.h>
54 #include <sys/dirent.h>
55 #include <sys/event.h>
56 #include <sys/eventhandler.h>
57 #include <sys/extattr.h>
58 #include <sys/file.h>
59 #include <sys/fcntl.h>
60 #include <sys/jail.h>
61 #include <sys/kdb.h>
62 #include <sys/kernel.h>
63 #include <sys/kthread.h>
64 #include <sys/lockf.h>
65 #include <sys/malloc.h>
66 #include <sys/mount.h>
67 #include <sys/namei.h>
68 #include <sys/pctrie.h>
69 #include <sys/priv.h>
70 #include <sys/reboot.h>
71 #include <sys/rwlock.h>
72 #include <sys/sched.h>
73 #include <sys/sleepqueue.h>
74 #include <sys/smp.h>
75 #include <sys/stat.h>
76 #include <sys/sysctl.h>
77 #include <sys/syslog.h>
78 #include <sys/vmmeter.h>
79 #include <sys/vnode.h>
80 #include <sys/watchdog.h>
81
82 #include <machine/stdarg.h>
83
84 #include <security/mac/mac_framework.h>
85
86 #include <vm/vm.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_extern.h>
89 #include <vm/pmap.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_kern.h>
93 #include <vm/uma.h>
94
95 #ifdef DDB
96 #include <ddb/ddb.h>
97 #endif
98
99 static void delmntque(struct vnode *vp);
100 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
101 int slpflag, int slptimeo);
102 static void syncer_shutdown(void *arg, int howto);
103 static int vtryrecycle(struct vnode *vp);
104 static void v_incr_usecount(struct vnode *);
105 static void v_decr_usecount(struct vnode *);
106 static void v_decr_useonly(struct vnode *);
107 static void v_upgrade_usecount(struct vnode *);
108 static void vnlru_free(int);
109 static void vgonel(struct vnode *);
110 static void vfs_knllock(void *arg);
111 static void vfs_knlunlock(void *arg);
112 static void vfs_knl_assert_locked(void *arg);
113 static void vfs_knl_assert_unlocked(void *arg);
114 static void destroy_vpollinfo(struct vpollinfo *vi);
115
116 /*
117 * Number of vnodes in existence. Increased whenever getnewvnode()
118 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
119 */
120 static unsigned long numvnodes;
121
122 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
123 "Number of vnodes in existence");
124
125 /*
126 * Conversion tables for conversion from vnode types to inode formats
127 * and back.
128 */
129 enum vtype iftovt_tab[16] = {
130 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
131 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
132 };
133 int vttoif_tab[10] = {
134 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
135 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
136 };
137
138 /*
139 * List of vnodes that are ready for recycling.
140 */
141 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
142
143 /*
144 * Free vnode target. Free vnodes may simply be files which have been stat'd
145 * but not read. This is somewhat common, and a small cache of such files
146 * should be kept to avoid recreation costs.
147 */
148 static u_long wantfreevnodes;
149 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
150 /* Number of vnodes in the free list. */
151 static u_long freevnodes;
152 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0,
153 "Number of vnodes in the free list");
154
155 static int vlru_allow_cache_src;
156 SYSCTL_INT(_vfs, OID_AUTO, vlru_allow_cache_src, CTLFLAG_RW,
157 &vlru_allow_cache_src, 0, "Allow vlru to reclaim source vnode");
158
159 /*
160 * Various variables used for debugging the new implementation of
161 * reassignbuf().
162 * XXX these are probably of (very) limited utility now.
163 */
164 static int reassignbufcalls;
165 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
166 "Number of calls to reassignbuf");
167
168 /*
169 * Cache for the mount type id assigned to NFS. This is used for
170 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
171 */
172 int nfs_mount_type = -1;
173
174 /* To keep more than one thread at a time from running vfs_getnewfsid */
175 static struct mtx mntid_mtx;
176
177 /*
178 * Lock for any access to the following:
179 * vnode_free_list
180 * numvnodes
181 * freevnodes
182 */
183 static struct mtx vnode_free_list_mtx;
184
185 /* Publicly exported FS */
186 struct nfs_public nfs_pub;
187
188 static uma_zone_t buf_trie_zone;
189
190 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
191 static uma_zone_t vnode_zone;
192 static uma_zone_t vnodepoll_zone;
193
194 /*
195 * The workitem queue.
196 *
197 * It is useful to delay writes of file data and filesystem metadata
198 * for tens of seconds so that quickly created and deleted files need
199 * not waste disk bandwidth being created and removed. To realize this,
200 * we append vnodes to a "workitem" queue. When running with a soft
201 * updates implementation, most pending metadata dependencies should
202 * not wait for more than a few seconds. Thus, mounted on block devices
203 * are delayed only about a half the time that file data is delayed.
204 * Similarly, directory updates are more critical, so are only delayed
205 * about a third the time that file data is delayed. Thus, there are
206 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
207 * one each second (driven off the filesystem syncer process). The
208 * syncer_delayno variable indicates the next queue that is to be processed.
209 * Items that need to be processed soon are placed in this queue:
210 *
211 * syncer_workitem_pending[syncer_delayno]
212 *
213 * A delay of fifteen seconds is done by placing the request fifteen
214 * entries later in the queue:
215 *
216 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
217 *
218 */
219 static int syncer_delayno;
220 static long syncer_mask;
221 LIST_HEAD(synclist, bufobj);
222 static struct synclist *syncer_workitem_pending;
223 /*
224 * The sync_mtx protects:
225 * bo->bo_synclist
226 * sync_vnode_count
227 * syncer_delayno
228 * syncer_state
229 * syncer_workitem_pending
230 * syncer_worklist_len
231 * rushjob
232 */
233 static struct mtx sync_mtx;
234 static struct cv sync_wakeup;
235
236 #define SYNCER_MAXDELAY 32
237 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
238 static int syncdelay = 30; /* max time to delay syncing data */
239 static int filedelay = 30; /* time to delay syncing files */
240 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
241 "Time to delay syncing files (in seconds)");
242 static int dirdelay = 29; /* time to delay syncing directories */
243 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
244 "Time to delay syncing directories (in seconds)");
245 static int metadelay = 28; /* time to delay syncing metadata */
246 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
247 "Time to delay syncing metadata (in seconds)");
248 static int rushjob; /* number of slots to run ASAP */
249 static int stat_rush_requests; /* number of times I/O speeded up */
250 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
251 "Number of times I/O speeded up (rush requests)");
252
253 /*
254 * When shutting down the syncer, run it at four times normal speed.
255 */
256 #define SYNCER_SHUTDOWN_SPEEDUP 4
257 static int sync_vnode_count;
258 static int syncer_worklist_len;
259 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
260 syncer_state;
261
262 /*
263 * Number of vnodes we want to exist at any one time. This is mostly used
264 * to size hash tables in vnode-related code. It is normally not used in
265 * getnewvnode(), as wantfreevnodes is normally nonzero.)
266 *
267 * XXX desiredvnodes is historical cruft and should not exist.
268 */
269 int desiredvnodes;
270 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
271 &desiredvnodes, 0, "Maximum number of vnodes");
272 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
273 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
274 static int vnlru_nowhere;
275 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
276 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
277
278 /*
279 * Macros to control when a vnode is freed and recycled. All require
280 * the vnode interlock.
281 */
282 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
283 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
284 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
285
286 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
287 static int vnsz2log;
288
289 /*
290 * Support for the bufobj clean & dirty pctrie.
291 */
292 static void *
293 buf_trie_alloc(struct pctrie *ptree)
294 {
295
296 return uma_zalloc(buf_trie_zone, M_NOWAIT);
297 }
298
299 static void
300 buf_trie_free(struct pctrie *ptree, void *node)
301 {
302
303 uma_zfree(buf_trie_zone, node);
304 }
305 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
306
307 /*
308 * Initialize the vnode management data structures.
309 *
310 * Reevaluate the following cap on the number of vnodes after the physical
311 * memory size exceeds 512GB. In the limit, as the physical memory size
312 * grows, the ratio of physical pages to vnodes approaches sixteen to one.
313 */
314 #ifndef MAXVNODES_MAX
315 #define MAXVNODES_MAX (512 * (1024 * 1024 * 1024 / (int)PAGE_SIZE / 16))
316 #endif
317 static void
318 vntblinit(void *dummy __unused)
319 {
320 u_int i;
321 int physvnodes, virtvnodes;
322
323 /*
324 * Desiredvnodes is a function of the physical memory size and the
325 * kernel's heap size. Generally speaking, it scales with the
326 * physical memory size. The ratio of desiredvnodes to physical pages
327 * is one to four until desiredvnodes exceeds 98,304. Thereafter, the
328 * marginal ratio of desiredvnodes to physical pages is one to
329 * sixteen. However, desiredvnodes is limited by the kernel's heap
330 * size. The memory required by desiredvnodes vnodes and vm objects
331 * may not exceed one seventh of the kernel's heap size.
332 */
333 physvnodes = maxproc + cnt.v_page_count / 16 + 3 * min(98304 * 4,
334 cnt.v_page_count) / 16;
335 virtvnodes = vm_kmem_size / (7 * (sizeof(struct vm_object) +
336 sizeof(struct vnode)));
337 desiredvnodes = min(physvnodes, virtvnodes);
338 if (desiredvnodes > MAXVNODES_MAX) {
339 if (bootverbose)
340 printf("Reducing kern.maxvnodes %d -> %d\n",
341 desiredvnodes, MAXVNODES_MAX);
342 desiredvnodes = MAXVNODES_MAX;
343 }
344 wantfreevnodes = desiredvnodes / 4;
345 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
346 TAILQ_INIT(&vnode_free_list);
347 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
348 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
349 NULL, NULL, UMA_ALIGN_PTR, 0);
350 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
351 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
352 /*
353 * Preallocate enough nodes to support one-per buf so that
354 * we can not fail an insert. reassignbuf() callers can not
355 * tolerate the insertion failure.
356 */
357 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
358 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
359 UMA_ZONE_NOFREE | UMA_ZONE_VM);
360 uma_prealloc(buf_trie_zone, nbuf);
361 /*
362 * Initialize the filesystem syncer.
363 */
364 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
365 &syncer_mask);
366 syncer_maxdelay = syncer_mask + 1;
367 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
368 cv_init(&sync_wakeup, "syncer");
369 for (i = 1; i <= sizeof(struct vnode); i <<= 1)
370 vnsz2log++;
371 vnsz2log--;
372 }
373 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
374
375
376 /*
377 * Mark a mount point as busy. Used to synchronize access and to delay
378 * unmounting. Eventually, mountlist_mtx is not released on failure.
379 *
380 * vfs_busy() is a custom lock, it can block the caller.
381 * vfs_busy() only sleeps if the unmount is active on the mount point.
382 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
383 * vnode belonging to mp.
384 *
385 * Lookup uses vfs_busy() to traverse mount points.
386 * root fs var fs
387 * / vnode lock A / vnode lock (/var) D
388 * /var vnode lock B /log vnode lock(/var/log) E
389 * vfs_busy lock C vfs_busy lock F
390 *
391 * Within each file system, the lock order is C->A->B and F->D->E.
392 *
393 * When traversing across mounts, the system follows that lock order:
394 *
395 * C->A->B
396 * |
397 * +->F->D->E
398 *
399 * The lookup() process for namei("/var") illustrates the process:
400 * VOP_LOOKUP() obtains B while A is held
401 * vfs_busy() obtains a shared lock on F while A and B are held
402 * vput() releases lock on B
403 * vput() releases lock on A
404 * VFS_ROOT() obtains lock on D while shared lock on F is held
405 * vfs_unbusy() releases shared lock on F
406 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
407 * Attempt to lock A (instead of vp_crossmp) while D is held would
408 * violate the global order, causing deadlocks.
409 *
410 * dounmount() locks B while F is drained.
411 */
412 int
413 vfs_busy(struct mount *mp, int flags)
414 {
415
416 MPASS((flags & ~MBF_MASK) == 0);
417 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
418
419 MNT_ILOCK(mp);
420 MNT_REF(mp);
421 /*
422 * If mount point is currenly being unmounted, sleep until the
423 * mount point fate is decided. If thread doing the unmounting fails,
424 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
425 * that this mount point has survived the unmount attempt and vfs_busy
426 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
427 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
428 * about to be really destroyed. vfs_busy needs to release its
429 * reference on the mount point in this case and return with ENOENT,
430 * telling the caller that mount mount it tried to busy is no longer
431 * valid.
432 */
433 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
434 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
435 MNT_REL(mp);
436 MNT_IUNLOCK(mp);
437 CTR1(KTR_VFS, "%s: failed busying before sleeping",
438 __func__);
439 return (ENOENT);
440 }
441 if (flags & MBF_MNTLSTLOCK)
442 mtx_unlock(&mountlist_mtx);
443 mp->mnt_kern_flag |= MNTK_MWAIT;
444 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
445 if (flags & MBF_MNTLSTLOCK)
446 mtx_lock(&mountlist_mtx);
447 MNT_ILOCK(mp);
448 }
449 if (flags & MBF_MNTLSTLOCK)
450 mtx_unlock(&mountlist_mtx);
451 mp->mnt_lockref++;
452 MNT_IUNLOCK(mp);
453 return (0);
454 }
455
456 /*
457 * Free a busy filesystem.
458 */
459 void
460 vfs_unbusy(struct mount *mp)
461 {
462
463 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
464 MNT_ILOCK(mp);
465 MNT_REL(mp);
466 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
467 mp->mnt_lockref--;
468 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
469 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
470 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
471 mp->mnt_kern_flag &= ~MNTK_DRAINING;
472 wakeup(&mp->mnt_lockref);
473 }
474 MNT_IUNLOCK(mp);
475 }
476
477 /*
478 * Lookup a mount point by filesystem identifier.
479 */
480 struct mount *
481 vfs_getvfs(fsid_t *fsid)
482 {
483 struct mount *mp;
484
485 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
486 mtx_lock(&mountlist_mtx);
487 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
488 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
489 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
490 vfs_ref(mp);
491 mtx_unlock(&mountlist_mtx);
492 return (mp);
493 }
494 }
495 mtx_unlock(&mountlist_mtx);
496 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
497 return ((struct mount *) 0);
498 }
499
500 /*
501 * Lookup a mount point by filesystem identifier, busying it before
502 * returning.
503 */
504 struct mount *
505 vfs_busyfs(fsid_t *fsid)
506 {
507 struct mount *mp;
508 int error;
509
510 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
511 mtx_lock(&mountlist_mtx);
512 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
513 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
514 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
515 error = vfs_busy(mp, MBF_MNTLSTLOCK);
516 if (error) {
517 mtx_unlock(&mountlist_mtx);
518 return (NULL);
519 }
520 return (mp);
521 }
522 }
523 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
524 mtx_unlock(&mountlist_mtx);
525 return ((struct mount *) 0);
526 }
527
528 /*
529 * Check if a user can access privileged mount options.
530 */
531 int
532 vfs_suser(struct mount *mp, struct thread *td)
533 {
534 int error;
535
536 /*
537 * If the thread is jailed, but this is not a jail-friendly file
538 * system, deny immediately.
539 */
540 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
541 return (EPERM);
542
543 /*
544 * If the file system was mounted outside the jail of the calling
545 * thread, deny immediately.
546 */
547 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
548 return (EPERM);
549
550 /*
551 * If file system supports delegated administration, we don't check
552 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
553 * by the file system itself.
554 * If this is not the user that did original mount, we check for
555 * the PRIV_VFS_MOUNT_OWNER privilege.
556 */
557 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
558 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
559 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
560 return (error);
561 }
562 return (0);
563 }
564
565 /*
566 * Get a new unique fsid. Try to make its val[0] unique, since this value
567 * will be used to create fake device numbers for stat(). Also try (but
568 * not so hard) make its val[0] unique mod 2^16, since some emulators only
569 * support 16-bit device numbers. We end up with unique val[0]'s for the
570 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
571 *
572 * Keep in mind that several mounts may be running in parallel. Starting
573 * the search one past where the previous search terminated is both a
574 * micro-optimization and a defense against returning the same fsid to
575 * different mounts.
576 */
577 void
578 vfs_getnewfsid(struct mount *mp)
579 {
580 static uint16_t mntid_base;
581 struct mount *nmp;
582 fsid_t tfsid;
583 int mtype;
584
585 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
586 mtx_lock(&mntid_mtx);
587 mtype = mp->mnt_vfc->vfc_typenum;
588 tfsid.val[1] = mtype;
589 mtype = (mtype & 0xFF) << 24;
590 for (;;) {
591 tfsid.val[0] = makedev(255,
592 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
593 mntid_base++;
594 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
595 break;
596 vfs_rel(nmp);
597 }
598 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
599 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
600 mtx_unlock(&mntid_mtx);
601 }
602
603 /*
604 * Knob to control the precision of file timestamps:
605 *
606 * 0 = seconds only; nanoseconds zeroed.
607 * 1 = seconds and nanoseconds, accurate within 1/HZ.
608 * 2 = seconds and nanoseconds, truncated to microseconds.
609 * >=3 = seconds and nanoseconds, maximum precision.
610 */
611 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
612
613 static int timestamp_precision = TSP_SEC;
614 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
615 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
616 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, "
617 "3+: sec + ns (max. precision))");
618
619 /*
620 * Get a current timestamp.
621 */
622 void
623 vfs_timestamp(struct timespec *tsp)
624 {
625 struct timeval tv;
626
627 switch (timestamp_precision) {
628 case TSP_SEC:
629 tsp->tv_sec = time_second;
630 tsp->tv_nsec = 0;
631 break;
632 case TSP_HZ:
633 getnanotime(tsp);
634 break;
635 case TSP_USEC:
636 microtime(&tv);
637 TIMEVAL_TO_TIMESPEC(&tv, tsp);
638 break;
639 case TSP_NSEC:
640 default:
641 nanotime(tsp);
642 break;
643 }
644 }
645
646 /*
647 * Set vnode attributes to VNOVAL
648 */
649 void
650 vattr_null(struct vattr *vap)
651 {
652
653 vap->va_type = VNON;
654 vap->va_size = VNOVAL;
655 vap->va_bytes = VNOVAL;
656 vap->va_mode = VNOVAL;
657 vap->va_nlink = VNOVAL;
658 vap->va_uid = VNOVAL;
659 vap->va_gid = VNOVAL;
660 vap->va_fsid = VNOVAL;
661 vap->va_fileid = VNOVAL;
662 vap->va_blocksize = VNOVAL;
663 vap->va_rdev = VNOVAL;
664 vap->va_atime.tv_sec = VNOVAL;
665 vap->va_atime.tv_nsec = VNOVAL;
666 vap->va_mtime.tv_sec = VNOVAL;
667 vap->va_mtime.tv_nsec = VNOVAL;
668 vap->va_ctime.tv_sec = VNOVAL;
669 vap->va_ctime.tv_nsec = VNOVAL;
670 vap->va_birthtime.tv_sec = VNOVAL;
671 vap->va_birthtime.tv_nsec = VNOVAL;
672 vap->va_flags = VNOVAL;
673 vap->va_gen = VNOVAL;
674 vap->va_vaflags = 0;
675 }
676
677 /*
678 * This routine is called when we have too many vnodes. It attempts
679 * to free <count> vnodes and will potentially free vnodes that still
680 * have VM backing store (VM backing store is typically the cause
681 * of a vnode blowout so we want to do this). Therefore, this operation
682 * is not considered cheap.
683 *
684 * A number of conditions may prevent a vnode from being reclaimed.
685 * the buffer cache may have references on the vnode, a directory
686 * vnode may still have references due to the namei cache representing
687 * underlying files, or the vnode may be in active use. It is not
688 * desireable to reuse such vnodes. These conditions may cause the
689 * number of vnodes to reach some minimum value regardless of what
690 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
691 */
692 static int
693 vlrureclaim(struct mount *mp)
694 {
695 struct vnode *vp;
696 int done;
697 int trigger;
698 int usevnodes;
699 int count;
700
701 /*
702 * Calculate the trigger point, don't allow user
703 * screwups to blow us up. This prevents us from
704 * recycling vnodes with lots of resident pages. We
705 * aren't trying to free memory, we are trying to
706 * free vnodes.
707 */
708 usevnodes = desiredvnodes;
709 if (usevnodes <= 0)
710 usevnodes = 1;
711 trigger = cnt.v_page_count * 2 / usevnodes;
712 done = 0;
713 vn_start_write(NULL, &mp, V_WAIT);
714 MNT_ILOCK(mp);
715 count = mp->mnt_nvnodelistsize / 10 + 1;
716 while (count != 0) {
717 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
718 while (vp != NULL && vp->v_type == VMARKER)
719 vp = TAILQ_NEXT(vp, v_nmntvnodes);
720 if (vp == NULL)
721 break;
722 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
723 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
724 --count;
725 if (!VI_TRYLOCK(vp))
726 goto next_iter;
727 /*
728 * If it's been deconstructed already, it's still
729 * referenced, or it exceeds the trigger, skip it.
730 */
731 if (vp->v_usecount ||
732 (!vlru_allow_cache_src &&
733 !LIST_EMPTY(&(vp)->v_cache_src)) ||
734 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
735 vp->v_object->resident_page_count > trigger)) {
736 VI_UNLOCK(vp);
737 goto next_iter;
738 }
739 MNT_IUNLOCK(mp);
740 vholdl(vp);
741 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
742 vdrop(vp);
743 goto next_iter_mntunlocked;
744 }
745 VI_LOCK(vp);
746 /*
747 * v_usecount may have been bumped after VOP_LOCK() dropped
748 * the vnode interlock and before it was locked again.
749 *
750 * It is not necessary to recheck VI_DOOMED because it can
751 * only be set by another thread that holds both the vnode
752 * lock and vnode interlock. If another thread has the
753 * vnode lock before we get to VOP_LOCK() and obtains the
754 * vnode interlock after VOP_LOCK() drops the vnode
755 * interlock, the other thread will be unable to drop the
756 * vnode lock before our VOP_LOCK() call fails.
757 */
758 if (vp->v_usecount ||
759 (!vlru_allow_cache_src &&
760 !LIST_EMPTY(&(vp)->v_cache_src)) ||
761 (vp->v_object != NULL &&
762 vp->v_object->resident_page_count > trigger)) {
763 VOP_UNLOCK(vp, LK_INTERLOCK);
764 vdrop(vp);
765 goto next_iter_mntunlocked;
766 }
767 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
768 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
769 vgonel(vp);
770 VOP_UNLOCK(vp, 0);
771 vdropl(vp);
772 done++;
773 next_iter_mntunlocked:
774 if (!should_yield())
775 goto relock_mnt;
776 goto yield;
777 next_iter:
778 if (!should_yield())
779 continue;
780 MNT_IUNLOCK(mp);
781 yield:
782 kern_yield(PRI_USER);
783 relock_mnt:
784 MNT_ILOCK(mp);
785 }
786 MNT_IUNLOCK(mp);
787 vn_finished_write(mp);
788 return done;
789 }
790
791 /*
792 * Attempt to keep the free list at wantfreevnodes length.
793 */
794 static void
795 vnlru_free(int count)
796 {
797 struct vnode *vp;
798
799 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
800 for (; count > 0; count--) {
801 vp = TAILQ_FIRST(&vnode_free_list);
802 /*
803 * The list can be modified while the free_list_mtx
804 * has been dropped and vp could be NULL here.
805 */
806 if (!vp)
807 break;
808 VNASSERT(vp->v_op != NULL, vp,
809 ("vnlru_free: vnode already reclaimed."));
810 KASSERT((vp->v_iflag & VI_FREE) != 0,
811 ("Removing vnode not on freelist"));
812 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
813 ("Mangling active vnode"));
814 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
815 /*
816 * Don't recycle if we can't get the interlock.
817 */
818 if (!VI_TRYLOCK(vp)) {
819 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
820 continue;
821 }
822 VNASSERT(VCANRECYCLE(vp), vp,
823 ("vp inconsistent on freelist"));
824 freevnodes--;
825 vp->v_iflag &= ~VI_FREE;
826 vholdl(vp);
827 mtx_unlock(&vnode_free_list_mtx);
828 VI_UNLOCK(vp);
829 vtryrecycle(vp);
830 /*
831 * If the recycled succeeded this vdrop will actually free
832 * the vnode. If not it will simply place it back on
833 * the free list.
834 */
835 vdrop(vp);
836 mtx_lock(&vnode_free_list_mtx);
837 }
838 }
839 /*
840 * Attempt to recycle vnodes in a context that is always safe to block.
841 * Calling vlrurecycle() from the bowels of filesystem code has some
842 * interesting deadlock problems.
843 */
844 static struct proc *vnlruproc;
845 static int vnlruproc_sig;
846
847 static void
848 vnlru_proc(void)
849 {
850 struct mount *mp, *nmp;
851 int done;
852 struct proc *p = vnlruproc;
853
854 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
855 SHUTDOWN_PRI_FIRST);
856
857 for (;;) {
858 kproc_suspend_check(p);
859 mtx_lock(&vnode_free_list_mtx);
860 if (freevnodes > wantfreevnodes)
861 vnlru_free(freevnodes - wantfreevnodes);
862 if (numvnodes <= desiredvnodes * 9 / 10) {
863 vnlruproc_sig = 0;
864 wakeup(&vnlruproc_sig);
865 msleep(vnlruproc, &vnode_free_list_mtx,
866 PVFS|PDROP, "vlruwt", hz);
867 continue;
868 }
869 mtx_unlock(&vnode_free_list_mtx);
870 done = 0;
871 mtx_lock(&mountlist_mtx);
872 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
873 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
874 nmp = TAILQ_NEXT(mp, mnt_list);
875 continue;
876 }
877 done += vlrureclaim(mp);
878 mtx_lock(&mountlist_mtx);
879 nmp = TAILQ_NEXT(mp, mnt_list);
880 vfs_unbusy(mp);
881 }
882 mtx_unlock(&mountlist_mtx);
883 if (done == 0) {
884 #if 0
885 /* These messages are temporary debugging aids */
886 if (vnlru_nowhere < 5)
887 printf("vnlru process getting nowhere..\n");
888 else if (vnlru_nowhere == 5)
889 printf("vnlru process messages stopped.\n");
890 #endif
891 vnlru_nowhere++;
892 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
893 } else
894 kern_yield(PRI_USER);
895 }
896 }
897
898 static struct kproc_desc vnlru_kp = {
899 "vnlru",
900 vnlru_proc,
901 &vnlruproc
902 };
903 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
904 &vnlru_kp);
905
906 /*
907 * Routines having to do with the management of the vnode table.
908 */
909
910 /*
911 * Try to recycle a freed vnode. We abort if anyone picks up a reference
912 * before we actually vgone(). This function must be called with the vnode
913 * held to prevent the vnode from being returned to the free list midway
914 * through vgone().
915 */
916 static int
917 vtryrecycle(struct vnode *vp)
918 {
919 struct mount *vnmp;
920
921 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
922 VNASSERT(vp->v_holdcnt, vp,
923 ("vtryrecycle: Recycling vp %p without a reference.", vp));
924 /*
925 * This vnode may found and locked via some other list, if so we
926 * can't recycle it yet.
927 */
928 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
929 CTR2(KTR_VFS,
930 "%s: impossible to recycle, vp %p lock is already held",
931 __func__, vp);
932 return (EWOULDBLOCK);
933 }
934 /*
935 * Don't recycle if its filesystem is being suspended.
936 */
937 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
938 VOP_UNLOCK(vp, 0);
939 CTR2(KTR_VFS,
940 "%s: impossible to recycle, cannot start the write for %p",
941 __func__, vp);
942 return (EBUSY);
943 }
944 /*
945 * If we got this far, we need to acquire the interlock and see if
946 * anyone picked up this vnode from another list. If not, we will
947 * mark it with DOOMED via vgonel() so that anyone who does find it
948 * will skip over it.
949 */
950 VI_LOCK(vp);
951 if (vp->v_usecount) {
952 VOP_UNLOCK(vp, LK_INTERLOCK);
953 vn_finished_write(vnmp);
954 CTR2(KTR_VFS,
955 "%s: impossible to recycle, %p is already referenced",
956 __func__, vp);
957 return (EBUSY);
958 }
959 if ((vp->v_iflag & VI_DOOMED) == 0)
960 vgonel(vp);
961 VOP_UNLOCK(vp, LK_INTERLOCK);
962 vn_finished_write(vnmp);
963 return (0);
964 }
965
966 /*
967 * Wait for available vnodes.
968 */
969 static int
970 getnewvnode_wait(int suspended)
971 {
972
973 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
974 if (numvnodes > desiredvnodes) {
975 if (suspended) {
976 /*
977 * File system is beeing suspended, we cannot risk a
978 * deadlock here, so allocate new vnode anyway.
979 */
980 if (freevnodes > wantfreevnodes)
981 vnlru_free(freevnodes - wantfreevnodes);
982 return (0);
983 }
984 if (vnlruproc_sig == 0) {
985 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
986 wakeup(vnlruproc);
987 }
988 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
989 "vlruwk", hz);
990 }
991 return (numvnodes > desiredvnodes ? ENFILE : 0);
992 }
993
994 void
995 getnewvnode_reserve(u_int count)
996 {
997 struct thread *td;
998
999 td = curthread;
1000 mtx_lock(&vnode_free_list_mtx);
1001 while (count > 0) {
1002 if (getnewvnode_wait(0) == 0) {
1003 count--;
1004 td->td_vp_reserv++;
1005 numvnodes++;
1006 }
1007 }
1008 mtx_unlock(&vnode_free_list_mtx);
1009 }
1010
1011 void
1012 getnewvnode_drop_reserve(void)
1013 {
1014 struct thread *td;
1015
1016 td = curthread;
1017 mtx_lock(&vnode_free_list_mtx);
1018 KASSERT(numvnodes >= td->td_vp_reserv, ("reserve too large"));
1019 numvnodes -= td->td_vp_reserv;
1020 mtx_unlock(&vnode_free_list_mtx);
1021 td->td_vp_reserv = 0;
1022 }
1023
1024 /*
1025 * Return the next vnode from the free list.
1026 */
1027 int
1028 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
1029 struct vnode **vpp)
1030 {
1031 struct vnode *vp;
1032 struct bufobj *bo;
1033 struct thread *td;
1034 int error;
1035
1036 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
1037 vp = NULL;
1038 td = curthread;
1039 if (td->td_vp_reserv > 0) {
1040 td->td_vp_reserv -= 1;
1041 goto alloc;
1042 }
1043 mtx_lock(&vnode_free_list_mtx);
1044 /*
1045 * Lend our context to reclaim vnodes if they've exceeded the max.
1046 */
1047 if (freevnodes > wantfreevnodes)
1048 vnlru_free(1);
1049 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag &
1050 MNTK_SUSPEND));
1051 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
1052 if (error != 0) {
1053 mtx_unlock(&vnode_free_list_mtx);
1054 return (error);
1055 }
1056 #endif
1057 numvnodes++;
1058 mtx_unlock(&vnode_free_list_mtx);
1059 alloc:
1060 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
1061 /*
1062 * Setup locks.
1063 */
1064 vp->v_vnlock = &vp->v_lock;
1065 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
1066 /*
1067 * By default, don't allow shared locks unless filesystems
1068 * opt-in.
1069 */
1070 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE | LK_IS_VNODE);
1071 /*
1072 * Initialize bufobj.
1073 */
1074 bo = &vp->v_bufobj;
1075 bo->__bo_vnode = vp;
1076 rw_init(BO_LOCKPTR(bo), "bufobj interlock");
1077 bo->bo_ops = &buf_ops_bio;
1078 bo->bo_private = vp;
1079 TAILQ_INIT(&bo->bo_clean.bv_hd);
1080 TAILQ_INIT(&bo->bo_dirty.bv_hd);
1081 /*
1082 * Initialize namecache.
1083 */
1084 LIST_INIT(&vp->v_cache_src);
1085 TAILQ_INIT(&vp->v_cache_dst);
1086 /*
1087 * Finalize various vnode identity bits.
1088 */
1089 vp->v_type = VNON;
1090 vp->v_tag = tag;
1091 vp->v_op = vops;
1092 v_incr_usecount(vp);
1093 vp->v_data = NULL;
1094 #ifdef MAC
1095 mac_vnode_init(vp);
1096 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1097 mac_vnode_associate_singlelabel(mp, vp);
1098 else if (mp == NULL && vops != &dead_vnodeops)
1099 printf("NULL mp in getnewvnode()\n");
1100 #endif
1101 if (mp != NULL) {
1102 bo->bo_bsize = mp->mnt_stat.f_iosize;
1103 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1104 vp->v_vflag |= VV_NOKNOTE;
1105 }
1106 rangelock_init(&vp->v_rl);
1107
1108 /*
1109 * For the filesystems which do not use vfs_hash_insert(),
1110 * still initialize v_hash to have vfs_hash_index() useful.
1111 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
1112 * its own hashing.
1113 */
1114 vp->v_hash = (uintptr_t)vp >> vnsz2log;
1115
1116 *vpp = vp;
1117 return (0);
1118 }
1119
1120 /*
1121 * Delete from old mount point vnode list, if on one.
1122 */
1123 static void
1124 delmntque(struct vnode *vp)
1125 {
1126 struct mount *mp;
1127 int active;
1128
1129 mp = vp->v_mount;
1130 if (mp == NULL)
1131 return;
1132 MNT_ILOCK(mp);
1133 VI_LOCK(vp);
1134 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
1135 ("Active vnode list size %d > Vnode list size %d",
1136 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
1137 active = vp->v_iflag & VI_ACTIVE;
1138 vp->v_iflag &= ~VI_ACTIVE;
1139 if (active) {
1140 mtx_lock(&vnode_free_list_mtx);
1141 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
1142 mp->mnt_activevnodelistsize--;
1143 mtx_unlock(&vnode_free_list_mtx);
1144 }
1145 vp->v_mount = NULL;
1146 VI_UNLOCK(vp);
1147 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1148 ("bad mount point vnode list size"));
1149 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1150 mp->mnt_nvnodelistsize--;
1151 MNT_REL(mp);
1152 MNT_IUNLOCK(mp);
1153 }
1154
1155 static void
1156 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1157 {
1158
1159 vp->v_data = NULL;
1160 vp->v_op = &dead_vnodeops;
1161 vgone(vp);
1162 vput(vp);
1163 }
1164
1165 /*
1166 * Insert into list of vnodes for the new mount point, if available.
1167 */
1168 int
1169 insmntque1(struct vnode *vp, struct mount *mp,
1170 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1171 {
1172
1173 KASSERT(vp->v_mount == NULL,
1174 ("insmntque: vnode already on per mount vnode list"));
1175 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1176 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
1177
1178 /*
1179 * We acquire the vnode interlock early to ensure that the
1180 * vnode cannot be recycled by another process releasing a
1181 * holdcnt on it before we get it on both the vnode list
1182 * and the active vnode list. The mount mutex protects only
1183 * manipulation of the vnode list and the vnode freelist
1184 * mutex protects only manipulation of the active vnode list.
1185 * Hence the need to hold the vnode interlock throughout.
1186 */
1187 MNT_ILOCK(mp);
1188 VI_LOCK(vp);
1189 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1190 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1191 mp->mnt_nvnodelistsize == 0)) &&
1192 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
1193 VI_UNLOCK(vp);
1194 MNT_IUNLOCK(mp);
1195 if (dtr != NULL)
1196 dtr(vp, dtr_arg);
1197 return (EBUSY);
1198 }
1199 vp->v_mount = mp;
1200 MNT_REF(mp);
1201 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1202 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1203 ("neg mount point vnode list size"));
1204 mp->mnt_nvnodelistsize++;
1205 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1206 ("Activating already active vnode"));
1207 vp->v_iflag |= VI_ACTIVE;
1208 mtx_lock(&vnode_free_list_mtx);
1209 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
1210 mp->mnt_activevnodelistsize++;
1211 mtx_unlock(&vnode_free_list_mtx);
1212 VI_UNLOCK(vp);
1213 MNT_IUNLOCK(mp);
1214 return (0);
1215 }
1216
1217 int
1218 insmntque(struct vnode *vp, struct mount *mp)
1219 {
1220
1221 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1222 }
1223
1224 /*
1225 * Flush out and invalidate all buffers associated with a bufobj
1226 * Called with the underlying object locked.
1227 */
1228 int
1229 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1230 {
1231 int error;
1232
1233 BO_LOCK(bo);
1234 if (flags & V_SAVE) {
1235 error = bufobj_wwait(bo, slpflag, slptimeo);
1236 if (error) {
1237 BO_UNLOCK(bo);
1238 return (error);
1239 }
1240 if (bo->bo_dirty.bv_cnt > 0) {
1241 BO_UNLOCK(bo);
1242 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1243 return (error);
1244 /*
1245 * XXX We could save a lock/unlock if this was only
1246 * enabled under INVARIANTS
1247 */
1248 BO_LOCK(bo);
1249 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1250 panic("vinvalbuf: dirty bufs");
1251 }
1252 }
1253 /*
1254 * If you alter this loop please notice that interlock is dropped and
1255 * reacquired in flushbuflist. Special care is needed to ensure that
1256 * no race conditions occur from this.
1257 */
1258 do {
1259 error = flushbuflist(&bo->bo_clean,
1260 flags, bo, slpflag, slptimeo);
1261 if (error == 0 && !(flags & V_CLEANONLY))
1262 error = flushbuflist(&bo->bo_dirty,
1263 flags, bo, slpflag, slptimeo);
1264 if (error != 0 && error != EAGAIN) {
1265 BO_UNLOCK(bo);
1266 return (error);
1267 }
1268 } while (error != 0);
1269
1270 /*
1271 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1272 * have write I/O in-progress but if there is a VM object then the
1273 * VM object can also have read-I/O in-progress.
1274 */
1275 do {
1276 bufobj_wwait(bo, 0, 0);
1277 BO_UNLOCK(bo);
1278 if (bo->bo_object != NULL) {
1279 VM_OBJECT_WLOCK(bo->bo_object);
1280 vm_object_pip_wait(bo->bo_object, "bovlbx");
1281 VM_OBJECT_WUNLOCK(bo->bo_object);
1282 }
1283 BO_LOCK(bo);
1284 } while (bo->bo_numoutput > 0);
1285 BO_UNLOCK(bo);
1286
1287 /*
1288 * Destroy the copy in the VM cache, too.
1289 */
1290 if (bo->bo_object != NULL &&
1291 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
1292 VM_OBJECT_WLOCK(bo->bo_object);
1293 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
1294 OBJPR_CLEANONLY : 0);
1295 VM_OBJECT_WUNLOCK(bo->bo_object);
1296 }
1297
1298 #ifdef INVARIANTS
1299 BO_LOCK(bo);
1300 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
1301 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1302 panic("vinvalbuf: flush failed");
1303 BO_UNLOCK(bo);
1304 #endif
1305 return (0);
1306 }
1307
1308 /*
1309 * Flush out and invalidate all buffers associated with a vnode.
1310 * Called with the underlying object locked.
1311 */
1312 int
1313 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1314 {
1315
1316 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1317 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1318 if (vp->v_object != NULL && vp->v_object->handle != vp)
1319 return (0);
1320 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1321 }
1322
1323 /*
1324 * Flush out buffers on the specified list.
1325 *
1326 */
1327 static int
1328 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1329 int slptimeo)
1330 {
1331 struct buf *bp, *nbp;
1332 int retval, error;
1333 daddr_t lblkno;
1334 b_xflags_t xflags;
1335
1336 ASSERT_BO_WLOCKED(bo);
1337
1338 retval = 0;
1339 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1340 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1341 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1342 continue;
1343 }
1344 lblkno = 0;
1345 xflags = 0;
1346 if (nbp != NULL) {
1347 lblkno = nbp->b_lblkno;
1348 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
1349 }
1350 retval = EAGAIN;
1351 error = BUF_TIMELOCK(bp,
1352 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
1353 "flushbuf", slpflag, slptimeo);
1354 if (error) {
1355 BO_LOCK(bo);
1356 return (error != ENOLCK ? error : EAGAIN);
1357 }
1358 KASSERT(bp->b_bufobj == bo,
1359 ("bp %p wrong b_bufobj %p should be %p",
1360 bp, bp->b_bufobj, bo));
1361 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1362 BUF_UNLOCK(bp);
1363 BO_LOCK(bo);
1364 return (EAGAIN);
1365 }
1366 /*
1367 * XXX Since there are no node locks for NFS, I
1368 * believe there is a slight chance that a delayed
1369 * write will occur while sleeping just above, so
1370 * check for it.
1371 */
1372 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1373 (flags & V_SAVE)) {
1374 bremfree(bp);
1375 bp->b_flags |= B_ASYNC;
1376 bwrite(bp);
1377 BO_LOCK(bo);
1378 return (EAGAIN); /* XXX: why not loop ? */
1379 }
1380 bremfree(bp);
1381 bp->b_flags |= (B_INVAL | B_RELBUF);
1382 bp->b_flags &= ~B_ASYNC;
1383 brelse(bp);
1384 BO_LOCK(bo);
1385 if (nbp != NULL &&
1386 (nbp->b_bufobj != bo ||
1387 nbp->b_lblkno != lblkno ||
1388 (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1389 break; /* nbp invalid */
1390 }
1391 return (retval);
1392 }
1393
1394 /*
1395 * Truncate a file's buffer and pages to a specified length. This
1396 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1397 * sync activity.
1398 */
1399 int
1400 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize)
1401 {
1402 struct buf *bp, *nbp;
1403 int anyfreed;
1404 int trunclbn;
1405 struct bufobj *bo;
1406
1407 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__,
1408 vp, cred, blksize, (uintmax_t)length);
1409
1410 /*
1411 * Round up to the *next* lbn.
1412 */
1413 trunclbn = (length + blksize - 1) / blksize;
1414
1415 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1416 restart:
1417 bo = &vp->v_bufobj;
1418 BO_LOCK(bo);
1419 anyfreed = 1;
1420 for (;anyfreed;) {
1421 anyfreed = 0;
1422 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1423 if (bp->b_lblkno < trunclbn)
1424 continue;
1425 if (BUF_LOCK(bp,
1426 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1427 BO_LOCKPTR(bo)) == ENOLCK)
1428 goto restart;
1429
1430 bremfree(bp);
1431 bp->b_flags |= (B_INVAL | B_RELBUF);
1432 bp->b_flags &= ~B_ASYNC;
1433 brelse(bp);
1434 anyfreed = 1;
1435
1436 BO_LOCK(bo);
1437 if (nbp != NULL &&
1438 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1439 (nbp->b_vp != vp) ||
1440 (nbp->b_flags & B_DELWRI))) {
1441 BO_UNLOCK(bo);
1442 goto restart;
1443 }
1444 }
1445
1446 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1447 if (bp->b_lblkno < trunclbn)
1448 continue;
1449 if (BUF_LOCK(bp,
1450 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1451 BO_LOCKPTR(bo)) == ENOLCK)
1452 goto restart;
1453 bremfree(bp);
1454 bp->b_flags |= (B_INVAL | B_RELBUF);
1455 bp->b_flags &= ~B_ASYNC;
1456 brelse(bp);
1457 anyfreed = 1;
1458
1459 BO_LOCK(bo);
1460 if (nbp != NULL &&
1461 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1462 (nbp->b_vp != vp) ||
1463 (nbp->b_flags & B_DELWRI) == 0)) {
1464 BO_UNLOCK(bo);
1465 goto restart;
1466 }
1467 }
1468 }
1469
1470 if (length > 0) {
1471 restartsync:
1472 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1473 if (bp->b_lblkno > 0)
1474 continue;
1475 /*
1476 * Since we hold the vnode lock this should only
1477 * fail if we're racing with the buf daemon.
1478 */
1479 if (BUF_LOCK(bp,
1480 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1481 BO_LOCKPTR(bo)) == ENOLCK) {
1482 goto restart;
1483 }
1484 VNASSERT((bp->b_flags & B_DELWRI), vp,
1485 ("buf(%p) on dirty queue without DELWRI", bp));
1486
1487 bremfree(bp);
1488 bawrite(bp);
1489 BO_LOCK(bo);
1490 goto restartsync;
1491 }
1492 }
1493
1494 bufobj_wwait(bo, 0, 0);
1495 BO_UNLOCK(bo);
1496 vnode_pager_setsize(vp, length);
1497
1498 return (0);
1499 }
1500
1501 static void
1502 buf_vlist_remove(struct buf *bp)
1503 {
1504 struct bufv *bv;
1505
1506 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1507 ASSERT_BO_WLOCKED(bp->b_bufobj);
1508 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1509 (BX_VNDIRTY|BX_VNCLEAN),
1510 ("buf_vlist_remove: Buf %p is on two lists", bp));
1511 if (bp->b_xflags & BX_VNDIRTY)
1512 bv = &bp->b_bufobj->bo_dirty;
1513 else
1514 bv = &bp->b_bufobj->bo_clean;
1515 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
1516 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1517 bv->bv_cnt--;
1518 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1519 }
1520
1521 /*
1522 * Add the buffer to the sorted clean or dirty block list.
1523 *
1524 * NOTE: xflags is passed as a constant, optimizing this inline function!
1525 */
1526 static void
1527 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1528 {
1529 struct bufv *bv;
1530 struct buf *n;
1531 int error;
1532
1533 ASSERT_BO_WLOCKED(bo);
1534 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1535 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1536 bp->b_xflags |= xflags;
1537 if (xflags & BX_VNDIRTY)
1538 bv = &bo->bo_dirty;
1539 else
1540 bv = &bo->bo_clean;
1541
1542 /*
1543 * Keep the list ordered. Optimize empty list insertion. Assume
1544 * we tend to grow at the tail so lookup_le should usually be cheaper
1545 * than _ge.
1546 */
1547 if (bv->bv_cnt == 0 ||
1548 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
1549 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1550 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
1551 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
1552 else
1553 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
1554 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
1555 if (error)
1556 panic("buf_vlist_add: Preallocated nodes insufficient.");
1557 bv->bv_cnt++;
1558 }
1559
1560 /*
1561 * Lookup a buffer using the splay tree. Note that we specifically avoid
1562 * shadow buffers used in background bitmap writes.
1563 *
1564 * This code isn't quite efficient as it could be because we are maintaining
1565 * two sorted lists and do not know which list the block resides in.
1566 *
1567 * During a "make buildworld" the desired buffer is found at one of
1568 * the roots more than 60% of the time. Thus, checking both roots
1569 * before performing either splay eliminates unnecessary splays on the
1570 * first tree splayed.
1571 */
1572 struct buf *
1573 gbincore(struct bufobj *bo, daddr_t lblkno)
1574 {
1575 struct buf *bp;
1576
1577 ASSERT_BO_LOCKED(bo);
1578 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
1579 if (bp != NULL)
1580 return (bp);
1581 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
1582 }
1583
1584 /*
1585 * Associate a buffer with a vnode.
1586 */
1587 void
1588 bgetvp(struct vnode *vp, struct buf *bp)
1589 {
1590 struct bufobj *bo;
1591
1592 bo = &vp->v_bufobj;
1593 ASSERT_BO_WLOCKED(bo);
1594 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1595
1596 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1597 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1598 ("bgetvp: bp already attached! %p", bp));
1599
1600 vhold(vp);
1601 bp->b_vp = vp;
1602 bp->b_bufobj = bo;
1603 /*
1604 * Insert onto list for new vnode.
1605 */
1606 buf_vlist_add(bp, bo, BX_VNCLEAN);
1607 }
1608
1609 /*
1610 * Disassociate a buffer from a vnode.
1611 */
1612 void
1613 brelvp(struct buf *bp)
1614 {
1615 struct bufobj *bo;
1616 struct vnode *vp;
1617
1618 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1619 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1620
1621 /*
1622 * Delete from old vnode list, if on one.
1623 */
1624 vp = bp->b_vp; /* XXX */
1625 bo = bp->b_bufobj;
1626 BO_LOCK(bo);
1627 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1628 buf_vlist_remove(bp);
1629 else
1630 panic("brelvp: Buffer %p not on queue.", bp);
1631 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1632 bo->bo_flag &= ~BO_ONWORKLST;
1633 mtx_lock(&sync_mtx);
1634 LIST_REMOVE(bo, bo_synclist);
1635 syncer_worklist_len--;
1636 mtx_unlock(&sync_mtx);
1637 }
1638 bp->b_vp = NULL;
1639 bp->b_bufobj = NULL;
1640 BO_UNLOCK(bo);
1641 vdrop(vp);
1642 }
1643
1644 /*
1645 * Add an item to the syncer work queue.
1646 */
1647 static void
1648 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1649 {
1650 int slot;
1651
1652 ASSERT_BO_WLOCKED(bo);
1653
1654 mtx_lock(&sync_mtx);
1655 if (bo->bo_flag & BO_ONWORKLST)
1656 LIST_REMOVE(bo, bo_synclist);
1657 else {
1658 bo->bo_flag |= BO_ONWORKLST;
1659 syncer_worklist_len++;
1660 }
1661
1662 if (delay > syncer_maxdelay - 2)
1663 delay = syncer_maxdelay - 2;
1664 slot = (syncer_delayno + delay) & syncer_mask;
1665
1666 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
1667 mtx_unlock(&sync_mtx);
1668 }
1669
1670 static int
1671 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1672 {
1673 int error, len;
1674
1675 mtx_lock(&sync_mtx);
1676 len = syncer_worklist_len - sync_vnode_count;
1677 mtx_unlock(&sync_mtx);
1678 error = SYSCTL_OUT(req, &len, sizeof(len));
1679 return (error);
1680 }
1681
1682 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1683 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1684
1685 static struct proc *updateproc;
1686 static void sched_sync(void);
1687 static struct kproc_desc up_kp = {
1688 "syncer",
1689 sched_sync,
1690 &updateproc
1691 };
1692 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
1693
1694 static int
1695 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
1696 {
1697 struct vnode *vp;
1698 struct mount *mp;
1699
1700 *bo = LIST_FIRST(slp);
1701 if (*bo == NULL)
1702 return (0);
1703 vp = (*bo)->__bo_vnode; /* XXX */
1704 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
1705 return (1);
1706 /*
1707 * We use vhold in case the vnode does not
1708 * successfully sync. vhold prevents the vnode from
1709 * going away when we unlock the sync_mtx so that
1710 * we can acquire the vnode interlock.
1711 */
1712 vholdl(vp);
1713 mtx_unlock(&sync_mtx);
1714 VI_UNLOCK(vp);
1715 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1716 vdrop(vp);
1717 mtx_lock(&sync_mtx);
1718 return (*bo == LIST_FIRST(slp));
1719 }
1720 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1721 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1722 VOP_UNLOCK(vp, 0);
1723 vn_finished_write(mp);
1724 BO_LOCK(*bo);
1725 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
1726 /*
1727 * Put us back on the worklist. The worklist
1728 * routine will remove us from our current
1729 * position and then add us back in at a later
1730 * position.
1731 */
1732 vn_syncer_add_to_worklist(*bo, syncdelay);
1733 }
1734 BO_UNLOCK(*bo);
1735 vdrop(vp);
1736 mtx_lock(&sync_mtx);
1737 return (0);
1738 }
1739
1740 /*
1741 * System filesystem synchronizer daemon.
1742 */
1743 static void
1744 sched_sync(void)
1745 {
1746 struct synclist *next, *slp;
1747 struct bufobj *bo;
1748 long starttime;
1749 struct thread *td = curthread;
1750 int last_work_seen;
1751 int net_worklist_len;
1752 int syncer_final_iter;
1753 int first_printf;
1754 int error;
1755
1756 last_work_seen = 0;
1757 syncer_final_iter = 0;
1758 first_printf = 1;
1759 syncer_state = SYNCER_RUNNING;
1760 starttime = time_uptime;
1761 td->td_pflags |= TDP_NORUNNINGBUF;
1762
1763 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1764 SHUTDOWN_PRI_LAST);
1765
1766 mtx_lock(&sync_mtx);
1767 for (;;) {
1768 if (syncer_state == SYNCER_FINAL_DELAY &&
1769 syncer_final_iter == 0) {
1770 mtx_unlock(&sync_mtx);
1771 kproc_suspend_check(td->td_proc);
1772 mtx_lock(&sync_mtx);
1773 }
1774 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1775 if (syncer_state != SYNCER_RUNNING &&
1776 starttime != time_uptime) {
1777 if (first_printf) {
1778 printf("\nSyncing disks, vnodes remaining...");
1779 first_printf = 0;
1780 }
1781 printf("%d ", net_worklist_len);
1782 }
1783 starttime = time_uptime;
1784
1785 /*
1786 * Push files whose dirty time has expired. Be careful
1787 * of interrupt race on slp queue.
1788 *
1789 * Skip over empty worklist slots when shutting down.
1790 */
1791 do {
1792 slp = &syncer_workitem_pending[syncer_delayno];
1793 syncer_delayno += 1;
1794 if (syncer_delayno == syncer_maxdelay)
1795 syncer_delayno = 0;
1796 next = &syncer_workitem_pending[syncer_delayno];
1797 /*
1798 * If the worklist has wrapped since the
1799 * it was emptied of all but syncer vnodes,
1800 * switch to the FINAL_DELAY state and run
1801 * for one more second.
1802 */
1803 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1804 net_worklist_len == 0 &&
1805 last_work_seen == syncer_delayno) {
1806 syncer_state = SYNCER_FINAL_DELAY;
1807 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1808 }
1809 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1810 syncer_worklist_len > 0);
1811
1812 /*
1813 * Keep track of the last time there was anything
1814 * on the worklist other than syncer vnodes.
1815 * Return to the SHUTTING_DOWN state if any
1816 * new work appears.
1817 */
1818 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1819 last_work_seen = syncer_delayno;
1820 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1821 syncer_state = SYNCER_SHUTTING_DOWN;
1822 while (!LIST_EMPTY(slp)) {
1823 error = sync_vnode(slp, &bo, td);
1824 if (error == 1) {
1825 LIST_REMOVE(bo, bo_synclist);
1826 LIST_INSERT_HEAD(next, bo, bo_synclist);
1827 continue;
1828 }
1829
1830 if (first_printf == 0)
1831 wdog_kern_pat(WD_LASTVAL);
1832
1833 }
1834 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1835 syncer_final_iter--;
1836 /*
1837 * The variable rushjob allows the kernel to speed up the
1838 * processing of the filesystem syncer process. A rushjob
1839 * value of N tells the filesystem syncer to process the next
1840 * N seconds worth of work on its queue ASAP. Currently rushjob
1841 * is used by the soft update code to speed up the filesystem
1842 * syncer process when the incore state is getting so far
1843 * ahead of the disk that the kernel memory pool is being
1844 * threatened with exhaustion.
1845 */
1846 if (rushjob > 0) {
1847 rushjob -= 1;
1848 continue;
1849 }
1850 /*
1851 * Just sleep for a short period of time between
1852 * iterations when shutting down to allow some I/O
1853 * to happen.
1854 *
1855 * If it has taken us less than a second to process the
1856 * current work, then wait. Otherwise start right over
1857 * again. We can still lose time if any single round
1858 * takes more than two seconds, but it does not really
1859 * matter as we are just trying to generally pace the
1860 * filesystem activity.
1861 */
1862 if (syncer_state != SYNCER_RUNNING ||
1863 time_uptime == starttime) {
1864 thread_lock(td);
1865 sched_prio(td, PPAUSE);
1866 thread_unlock(td);
1867 }
1868 if (syncer_state != SYNCER_RUNNING)
1869 cv_timedwait(&sync_wakeup, &sync_mtx,
1870 hz / SYNCER_SHUTDOWN_SPEEDUP);
1871 else if (time_uptime == starttime)
1872 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
1873 }
1874 }
1875
1876 /*
1877 * Request the syncer daemon to speed up its work.
1878 * We never push it to speed up more than half of its
1879 * normal turn time, otherwise it could take over the cpu.
1880 */
1881 int
1882 speedup_syncer(void)
1883 {
1884 int ret = 0;
1885
1886 mtx_lock(&sync_mtx);
1887 if (rushjob < syncdelay / 2) {
1888 rushjob += 1;
1889 stat_rush_requests += 1;
1890 ret = 1;
1891 }
1892 mtx_unlock(&sync_mtx);
1893 cv_broadcast(&sync_wakeup);
1894 return (ret);
1895 }
1896
1897 /*
1898 * Tell the syncer to speed up its work and run though its work
1899 * list several times, then tell it to shut down.
1900 */
1901 static void
1902 syncer_shutdown(void *arg, int howto)
1903 {
1904
1905 if (howto & RB_NOSYNC)
1906 return;
1907 mtx_lock(&sync_mtx);
1908 syncer_state = SYNCER_SHUTTING_DOWN;
1909 rushjob = 0;
1910 mtx_unlock(&sync_mtx);
1911 cv_broadcast(&sync_wakeup);
1912 kproc_shutdown(arg, howto);
1913 }
1914
1915 /*
1916 * Reassign a buffer from one vnode to another.
1917 * Used to assign file specific control information
1918 * (indirect blocks) to the vnode to which they belong.
1919 */
1920 void
1921 reassignbuf(struct buf *bp)
1922 {
1923 struct vnode *vp;
1924 struct bufobj *bo;
1925 int delay;
1926 #ifdef INVARIANTS
1927 struct bufv *bv;
1928 #endif
1929
1930 vp = bp->b_vp;
1931 bo = bp->b_bufobj;
1932 ++reassignbufcalls;
1933
1934 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
1935 bp, bp->b_vp, bp->b_flags);
1936 /*
1937 * B_PAGING flagged buffers cannot be reassigned because their vp
1938 * is not fully linked in.
1939 */
1940 if (bp->b_flags & B_PAGING)
1941 panic("cannot reassign paging buffer");
1942
1943 /*
1944 * Delete from old vnode list, if on one.
1945 */
1946 BO_LOCK(bo);
1947 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1948 buf_vlist_remove(bp);
1949 else
1950 panic("reassignbuf: Buffer %p not on queue.", bp);
1951 /*
1952 * If dirty, put on list of dirty buffers; otherwise insert onto list
1953 * of clean buffers.
1954 */
1955 if (bp->b_flags & B_DELWRI) {
1956 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
1957 switch (vp->v_type) {
1958 case VDIR:
1959 delay = dirdelay;
1960 break;
1961 case VCHR:
1962 delay = metadelay;
1963 break;
1964 default:
1965 delay = filedelay;
1966 }
1967 vn_syncer_add_to_worklist(bo, delay);
1968 }
1969 buf_vlist_add(bp, bo, BX_VNDIRTY);
1970 } else {
1971 buf_vlist_add(bp, bo, BX_VNCLEAN);
1972
1973 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1974 mtx_lock(&sync_mtx);
1975 LIST_REMOVE(bo, bo_synclist);
1976 syncer_worklist_len--;
1977 mtx_unlock(&sync_mtx);
1978 bo->bo_flag &= ~BO_ONWORKLST;
1979 }
1980 }
1981 #ifdef INVARIANTS
1982 bv = &bo->bo_clean;
1983 bp = TAILQ_FIRST(&bv->bv_hd);
1984 KASSERT(bp == NULL || bp->b_bufobj == bo,
1985 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1986 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1987 KASSERT(bp == NULL || bp->b_bufobj == bo,
1988 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1989 bv = &bo->bo_dirty;
1990 bp = TAILQ_FIRST(&bv->bv_hd);
1991 KASSERT(bp == NULL || bp->b_bufobj == bo,
1992 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1993 bp = TAILQ_LAST(&bv->bv_hd, buflists);
1994 KASSERT(bp == NULL || bp->b_bufobj == bo,
1995 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
1996 #endif
1997 BO_UNLOCK(bo);
1998 }
1999
2000 /*
2001 * Increment the use and hold counts on the vnode, taking care to reference
2002 * the driver's usecount if this is a chardev. The vholdl() will remove
2003 * the vnode from the free list if it is presently free. Requires the
2004 * vnode interlock and returns with it held.
2005 */
2006 static void
2007 v_incr_usecount(struct vnode *vp)
2008 {
2009
2010 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2011 vp->v_usecount++;
2012 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2013 dev_lock();
2014 vp->v_rdev->si_usecount++;
2015 dev_unlock();
2016 }
2017 vholdl(vp);
2018 }
2019
2020 /*
2021 * Turn a holdcnt into a use+holdcnt such that only one call to
2022 * v_decr_usecount is needed.
2023 */
2024 static void
2025 v_upgrade_usecount(struct vnode *vp)
2026 {
2027
2028 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2029 vp->v_usecount++;
2030 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2031 dev_lock();
2032 vp->v_rdev->si_usecount++;
2033 dev_unlock();
2034 }
2035 }
2036
2037 /*
2038 * Decrement the vnode use and hold count along with the driver's usecount
2039 * if this is a chardev. The vdropl() below releases the vnode interlock
2040 * as it may free the vnode.
2041 */
2042 static void
2043 v_decr_usecount(struct vnode *vp)
2044 {
2045
2046 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2047 VNASSERT(vp->v_usecount > 0, vp,
2048 ("v_decr_usecount: negative usecount"));
2049 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2050 vp->v_usecount--;
2051 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2052 dev_lock();
2053 vp->v_rdev->si_usecount--;
2054 dev_unlock();
2055 }
2056 vdropl(vp);
2057 }
2058
2059 /*
2060 * Decrement only the use count and driver use count. This is intended to
2061 * be paired with a follow on vdropl() to release the remaining hold count.
2062 * In this way we may vgone() a vnode with a 0 usecount without risk of
2063 * having it end up on a free list because the hold count is kept above 0.
2064 */
2065 static void
2066 v_decr_useonly(struct vnode *vp)
2067 {
2068
2069 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2070 VNASSERT(vp->v_usecount > 0, vp,
2071 ("v_decr_useonly: negative usecount"));
2072 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2073 vp->v_usecount--;
2074 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2075 dev_lock();
2076 vp->v_rdev->si_usecount--;
2077 dev_unlock();
2078 }
2079 }
2080
2081 /*
2082 * Grab a particular vnode from the free list, increment its
2083 * reference count and lock it. VI_DOOMED is set if the vnode
2084 * is being destroyed. Only callers who specify LK_RETRY will
2085 * see doomed vnodes. If inactive processing was delayed in
2086 * vput try to do it here.
2087 */
2088 int
2089 vget(struct vnode *vp, int flags, struct thread *td)
2090 {
2091 int error;
2092
2093 error = 0;
2094 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2095 ("vget: invalid lock operation"));
2096 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2097
2098 if ((flags & LK_INTERLOCK) == 0)
2099 VI_LOCK(vp);
2100 vholdl(vp);
2101 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) {
2102 vdrop(vp);
2103 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2104 vp);
2105 return (error);
2106 }
2107 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2108 panic("vget: vn_lock failed to return ENOENT\n");
2109 VI_LOCK(vp);
2110 /* Upgrade our holdcnt to a usecount. */
2111 v_upgrade_usecount(vp);
2112 /*
2113 * We don't guarantee that any particular close will
2114 * trigger inactive processing so just make a best effort
2115 * here at preventing a reference to a removed file. If
2116 * we don't succeed no harm is done.
2117 */
2118 if (vp->v_iflag & VI_OWEINACT) {
2119 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2120 (flags & LK_NOWAIT) == 0)
2121 vinactive(vp, td);
2122 vp->v_iflag &= ~VI_OWEINACT;
2123 }
2124 VI_UNLOCK(vp);
2125 return (0);
2126 }
2127
2128 /*
2129 * Increase the reference count of a vnode.
2130 */
2131 void
2132 vref(struct vnode *vp)
2133 {
2134
2135 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2136 VI_LOCK(vp);
2137 v_incr_usecount(vp);
2138 VI_UNLOCK(vp);
2139 }
2140
2141 /*
2142 * Return reference count of a vnode.
2143 *
2144 * The results of this call are only guaranteed when some mechanism other
2145 * than the VI lock is used to stop other processes from gaining references
2146 * to the vnode. This may be the case if the caller holds the only reference.
2147 * This is also useful when stale data is acceptable as race conditions may
2148 * be accounted for by some other means.
2149 */
2150 int
2151 vrefcnt(struct vnode *vp)
2152 {
2153 int usecnt;
2154
2155 VI_LOCK(vp);
2156 usecnt = vp->v_usecount;
2157 VI_UNLOCK(vp);
2158
2159 return (usecnt);
2160 }
2161
2162 #define VPUTX_VRELE 1
2163 #define VPUTX_VPUT 2
2164 #define VPUTX_VUNREF 3
2165
2166 static void
2167 vputx(struct vnode *vp, int func)
2168 {
2169 int error;
2170
2171 KASSERT(vp != NULL, ("vputx: null vp"));
2172 if (func == VPUTX_VUNREF)
2173 ASSERT_VOP_LOCKED(vp, "vunref");
2174 else if (func == VPUTX_VPUT)
2175 ASSERT_VOP_LOCKED(vp, "vput");
2176 else
2177 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2178 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2179 VI_LOCK(vp);
2180
2181 /* Skip this v_writecount check if we're going to panic below. */
2182 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2183 ("vputx: missed vn_close"));
2184 error = 0;
2185
2186 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2187 vp->v_usecount == 1)) {
2188 if (func == VPUTX_VPUT)
2189 VOP_UNLOCK(vp, 0);
2190 v_decr_usecount(vp);
2191 return;
2192 }
2193
2194 if (vp->v_usecount != 1) {
2195 vprint("vputx: negative ref count", vp);
2196 panic("vputx: negative ref cnt");
2197 }
2198 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
2199 /*
2200 * We want to hold the vnode until the inactive finishes to
2201 * prevent vgone() races. We drop the use count here and the
2202 * hold count below when we're done.
2203 */
2204 v_decr_useonly(vp);
2205 /*
2206 * We must call VOP_INACTIVE with the node locked. Mark
2207 * as VI_DOINGINACT to avoid recursion.
2208 */
2209 vp->v_iflag |= VI_OWEINACT;
2210 switch (func) {
2211 case VPUTX_VRELE:
2212 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2213 VI_LOCK(vp);
2214 break;
2215 case VPUTX_VPUT:
2216 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2217 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
2218 LK_NOWAIT);
2219 VI_LOCK(vp);
2220 }
2221 break;
2222 case VPUTX_VUNREF:
2223 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2224 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
2225 VI_LOCK(vp);
2226 }
2227 break;
2228 }
2229 if (vp->v_usecount > 0)
2230 vp->v_iflag &= ~VI_OWEINACT;
2231 if (error == 0) {
2232 if (vp->v_iflag & VI_OWEINACT)
2233 vinactive(vp, curthread);
2234 if (func != VPUTX_VUNREF)
2235 VOP_UNLOCK(vp, 0);
2236 }
2237 vdropl(vp);
2238 }
2239
2240 /*
2241 * Vnode put/release.
2242 * If count drops to zero, call inactive routine and return to freelist.
2243 */
2244 void
2245 vrele(struct vnode *vp)
2246 {
2247
2248 vputx(vp, VPUTX_VRELE);
2249 }
2250
2251 /*
2252 * Release an already locked vnode. This give the same effects as
2253 * unlock+vrele(), but takes less time and avoids releasing and
2254 * re-aquiring the lock (as vrele() acquires the lock internally.)
2255 */
2256 void
2257 vput(struct vnode *vp)
2258 {
2259
2260 vputx(vp, VPUTX_VPUT);
2261 }
2262
2263 /*
2264 * Release an exclusively locked vnode. Do not unlock the vnode lock.
2265 */
2266 void
2267 vunref(struct vnode *vp)
2268 {
2269
2270 vputx(vp, VPUTX_VUNREF);
2271 }
2272
2273 /*
2274 * Somebody doesn't want the vnode recycled.
2275 */
2276 void
2277 vhold(struct vnode *vp)
2278 {
2279
2280 VI_LOCK(vp);
2281 vholdl(vp);
2282 VI_UNLOCK(vp);
2283 }
2284
2285 /*
2286 * Increase the hold count and activate if this is the first reference.
2287 */
2288 void
2289 vholdl(struct vnode *vp)
2290 {
2291 struct mount *mp;
2292
2293 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2294 vp->v_holdcnt++;
2295 if (!VSHOULDBUSY(vp))
2296 return;
2297 ASSERT_VI_LOCKED(vp, "vholdl");
2298 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
2299 VNASSERT(vp->v_op != NULL, vp, ("vholdl: vnode already reclaimed."));
2300 /*
2301 * Remove a vnode from the free list, mark it as in use,
2302 * and put it on the active list.
2303 */
2304 mtx_lock(&vnode_free_list_mtx);
2305 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
2306 freevnodes--;
2307 vp->v_iflag &= ~(VI_FREE|VI_AGE);
2308 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
2309 ("Activating already active vnode"));
2310 vp->v_iflag |= VI_ACTIVE;
2311 mp = vp->v_mount;
2312 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
2313 mp->mnt_activevnodelistsize++;
2314 mtx_unlock(&vnode_free_list_mtx);
2315 }
2316
2317 /*
2318 * Note that there is one less who cares about this vnode.
2319 * vdrop() is the opposite of vhold().
2320 */
2321 void
2322 vdrop(struct vnode *vp)
2323 {
2324
2325 VI_LOCK(vp);
2326 vdropl(vp);
2327 }
2328
2329 /*
2330 * Drop the hold count of the vnode. If this is the last reference to
2331 * the vnode we place it on the free list unless it has been vgone'd
2332 * (marked VI_DOOMED) in which case we will free it.
2333 */
2334 void
2335 vdropl(struct vnode *vp)
2336 {
2337 struct bufobj *bo;
2338 struct mount *mp;
2339 int active;
2340
2341 ASSERT_VI_LOCKED(vp, "vdropl");
2342 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2343 if (vp->v_holdcnt <= 0)
2344 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2345 vp->v_holdcnt--;
2346 if (vp->v_holdcnt > 0) {
2347 VI_UNLOCK(vp);
2348 return;
2349 }
2350 if ((vp->v_iflag & VI_DOOMED) == 0) {
2351 /*
2352 * Mark a vnode as free: remove it from its active list
2353 * and put it up for recycling on the freelist.
2354 */
2355 VNASSERT(vp->v_op != NULL, vp,
2356 ("vdropl: vnode already reclaimed."));
2357 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2358 ("vnode already free"));
2359 VNASSERT(VSHOULDFREE(vp), vp,
2360 ("vdropl: freeing when we shouldn't"));
2361 active = vp->v_iflag & VI_ACTIVE;
2362 vp->v_iflag &= ~VI_ACTIVE;
2363 mp = vp->v_mount;
2364 mtx_lock(&vnode_free_list_mtx);
2365 if (active) {
2366 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp,
2367 v_actfreelist);
2368 mp->mnt_activevnodelistsize--;
2369 }
2370 if (vp->v_iflag & VI_AGE) {
2371 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_actfreelist);
2372 } else {
2373 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
2374 }
2375 freevnodes++;
2376 vp->v_iflag &= ~VI_AGE;
2377 vp->v_iflag |= VI_FREE;
2378 mtx_unlock(&vnode_free_list_mtx);
2379 VI_UNLOCK(vp);
2380 return;
2381 }
2382 /*
2383 * The vnode has been marked for destruction, so free it.
2384 */
2385 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2386 mtx_lock(&vnode_free_list_mtx);
2387 numvnodes--;
2388 mtx_unlock(&vnode_free_list_mtx);
2389 bo = &vp->v_bufobj;
2390 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2391 ("cleaned vnode still on the free list."));
2392 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2393 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
2394 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2395 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2396 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2397 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2398 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2399 ("clean blk trie not empty"));
2400 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2401 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2402 ("dirty blk trie not empty"));
2403 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
2404 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
2405 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
2406 VI_UNLOCK(vp);
2407 #ifdef MAC
2408 mac_vnode_destroy(vp);
2409 #endif
2410 if (vp->v_pollinfo != NULL)
2411 destroy_vpollinfo(vp->v_pollinfo);
2412 #ifdef INVARIANTS
2413 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
2414 vp->v_op = NULL;
2415 #endif
2416 rangelock_destroy(&vp->v_rl);
2417 lockdestroy(vp->v_vnlock);
2418 mtx_destroy(&vp->v_interlock);
2419 rw_destroy(BO_LOCKPTR(bo));
2420 uma_zfree(vnode_zone, vp);
2421 }
2422
2423 /*
2424 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2425 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2426 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2427 * failed lock upgrade.
2428 */
2429 void
2430 vinactive(struct vnode *vp, struct thread *td)
2431 {
2432 struct vm_object *obj;
2433
2434 ASSERT_VOP_ELOCKED(vp, "vinactive");
2435 ASSERT_VI_LOCKED(vp, "vinactive");
2436 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2437 ("vinactive: recursed on VI_DOINGINACT"));
2438 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2439 vp->v_iflag |= VI_DOINGINACT;
2440 vp->v_iflag &= ~VI_OWEINACT;
2441 VI_UNLOCK(vp);
2442 /*
2443 * Before moving off the active list, we must be sure that any
2444 * modified pages are on the vnode's dirty list since these will
2445 * no longer be checked once the vnode is on the inactive list.
2446 * Because the vnode vm object keeps a hold reference on the vnode
2447 * if there is at least one resident non-cached page, the vnode
2448 * cannot leave the active list without the page cleanup done.
2449 */
2450 obj = vp->v_object;
2451 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
2452 VM_OBJECT_WLOCK(obj);
2453 vm_object_page_clean(obj, 0, 0, OBJPC_NOSYNC);
2454 VM_OBJECT_WUNLOCK(obj);
2455 }
2456 VOP_INACTIVE(vp, td);
2457 VI_LOCK(vp);
2458 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2459 ("vinactive: lost VI_DOINGINACT"));
2460 vp->v_iflag &= ~VI_DOINGINACT;
2461 }
2462
2463 /*
2464 * Remove any vnodes in the vnode table belonging to mount point mp.
2465 *
2466 * If FORCECLOSE is not specified, there should not be any active ones,
2467 * return error if any are found (nb: this is a user error, not a
2468 * system error). If FORCECLOSE is specified, detach any active vnodes
2469 * that are found.
2470 *
2471 * If WRITECLOSE is set, only flush out regular file vnodes open for
2472 * writing.
2473 *
2474 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2475 *
2476 * `rootrefs' specifies the base reference count for the root vnode
2477 * of this filesystem. The root vnode is considered busy if its
2478 * v_usecount exceeds this value. On a successful return, vflush(, td)
2479 * will call vrele() on the root vnode exactly rootrefs times.
2480 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2481 * be zero.
2482 */
2483 #ifdef DIAGNOSTIC
2484 static int busyprt = 0; /* print out busy vnodes */
2485 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
2486 #endif
2487
2488 int
2489 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
2490 {
2491 struct vnode *vp, *mvp, *rootvp = NULL;
2492 struct vattr vattr;
2493 int busy = 0, error;
2494
2495 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
2496 rootrefs, flags);
2497 if (rootrefs > 0) {
2498 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2499 ("vflush: bad args"));
2500 /*
2501 * Get the filesystem root vnode. We can vput() it
2502 * immediately, since with rootrefs > 0, it won't go away.
2503 */
2504 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
2505 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
2506 __func__, error);
2507 return (error);
2508 }
2509 vput(rootvp);
2510 }
2511 loop:
2512 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
2513 vholdl(vp);
2514 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
2515 if (error) {
2516 vdrop(vp);
2517 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2518 goto loop;
2519 }
2520 /*
2521 * Skip over a vnodes marked VV_SYSTEM.
2522 */
2523 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2524 VOP_UNLOCK(vp, 0);
2525 vdrop(vp);
2526 continue;
2527 }
2528 /*
2529 * If WRITECLOSE is set, flush out unlinked but still open
2530 * files (even if open only for reading) and regular file
2531 * vnodes open for writing.
2532 */
2533 if (flags & WRITECLOSE) {
2534 if (vp->v_object != NULL) {
2535 VM_OBJECT_WLOCK(vp->v_object);
2536 vm_object_page_clean(vp->v_object, 0, 0, 0);
2537 VM_OBJECT_WUNLOCK(vp->v_object);
2538 }
2539 error = VOP_FSYNC(vp, MNT_WAIT, td);
2540 if (error != 0) {
2541 VOP_UNLOCK(vp, 0);
2542 vdrop(vp);
2543 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2544 return (error);
2545 }
2546 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
2547 VI_LOCK(vp);
2548
2549 if ((vp->v_type == VNON ||
2550 (error == 0 && vattr.va_nlink > 0)) &&
2551 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2552 VOP_UNLOCK(vp, 0);
2553 vdropl(vp);
2554 continue;
2555 }
2556 } else
2557 VI_LOCK(vp);
2558 /*
2559 * With v_usecount == 0, all we need to do is clear out the
2560 * vnode data structures and we are done.
2561 *
2562 * If FORCECLOSE is set, forcibly close the vnode.
2563 */
2564 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2565 VNASSERT(vp->v_usecount == 0 ||
2566 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2567 ("device VNODE %p is FORCECLOSED", vp));
2568 vgonel(vp);
2569 } else {
2570 busy++;
2571 #ifdef DIAGNOSTIC
2572 if (busyprt)
2573 vprint("vflush: busy vnode", vp);
2574 #endif
2575 }
2576 VOP_UNLOCK(vp, 0);
2577 vdropl(vp);
2578 }
2579 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2580 /*
2581 * If just the root vnode is busy, and if its refcount
2582 * is equal to `rootrefs', then go ahead and kill it.
2583 */
2584 VI_LOCK(rootvp);
2585 KASSERT(busy > 0, ("vflush: not busy"));
2586 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2587 ("vflush: usecount %d < rootrefs %d",
2588 rootvp->v_usecount, rootrefs));
2589 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2590 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
2591 vgone(rootvp);
2592 VOP_UNLOCK(rootvp, 0);
2593 busy = 0;
2594 } else
2595 VI_UNLOCK(rootvp);
2596 }
2597 if (busy) {
2598 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
2599 busy);
2600 return (EBUSY);
2601 }
2602 for (; rootrefs > 0; rootrefs--)
2603 vrele(rootvp);
2604 return (0);
2605 }
2606
2607 /*
2608 * Recycle an unused vnode to the front of the free list.
2609 */
2610 int
2611 vrecycle(struct vnode *vp)
2612 {
2613 int recycled;
2614
2615 ASSERT_VOP_ELOCKED(vp, "vrecycle");
2616 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2617 recycled = 0;
2618 VI_LOCK(vp);
2619 if (vp->v_usecount == 0) {
2620 recycled = 1;
2621 vgonel(vp);
2622 }
2623 VI_UNLOCK(vp);
2624 return (recycled);
2625 }
2626
2627 /*
2628 * Eliminate all activity associated with a vnode
2629 * in preparation for reuse.
2630 */
2631 void
2632 vgone(struct vnode *vp)
2633 {
2634 VI_LOCK(vp);
2635 vgonel(vp);
2636 VI_UNLOCK(vp);
2637 }
2638
2639 static void
2640 notify_lowervp_vfs_dummy(struct mount *mp __unused,
2641 struct vnode *lowervp __unused)
2642 {
2643 }
2644
2645 /*
2646 * Notify upper mounts about reclaimed or unlinked vnode.
2647 */
2648 void
2649 vfs_notify_upper(struct vnode *vp, int event)
2650 {
2651 static struct vfsops vgonel_vfsops = {
2652 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy,
2653 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy,
2654 };
2655 struct mount *mp, *ump, *mmp;
2656
2657 mp = vp->v_mount;
2658 if (mp == NULL)
2659 return;
2660
2661 MNT_ILOCK(mp);
2662 if (TAILQ_EMPTY(&mp->mnt_uppers))
2663 goto unlock;
2664 MNT_IUNLOCK(mp);
2665 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO);
2666 mmp->mnt_op = &vgonel_vfsops;
2667 mmp->mnt_kern_flag |= MNTK_MARKER;
2668 MNT_ILOCK(mp);
2669 mp->mnt_kern_flag |= MNTK_VGONE_UPPER;
2670 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) {
2671 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) {
2672 ump = TAILQ_NEXT(ump, mnt_upper_link);
2673 continue;
2674 }
2675 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link);
2676 MNT_IUNLOCK(mp);
2677 switch (event) {
2678 case VFS_NOTIFY_UPPER_RECLAIM:
2679 VFS_RECLAIM_LOWERVP(ump, vp);
2680 break;
2681 case VFS_NOTIFY_UPPER_UNLINK:
2682 VFS_UNLINK_LOWERVP(ump, vp);
2683 break;
2684 default:
2685 KASSERT(0, ("invalid event %d", event));
2686 break;
2687 }
2688 MNT_ILOCK(mp);
2689 ump = TAILQ_NEXT(mmp, mnt_upper_link);
2690 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link);
2691 }
2692 free(mmp, M_TEMP);
2693 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER;
2694 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) {
2695 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER;
2696 wakeup(&mp->mnt_uppers);
2697 }
2698 unlock:
2699 MNT_IUNLOCK(mp);
2700 }
2701
2702 /*
2703 * vgone, with the vp interlock held.
2704 */
2705 void
2706 vgonel(struct vnode *vp)
2707 {
2708 struct thread *td;
2709 int oweinact;
2710 int active;
2711 struct mount *mp;
2712
2713 ASSERT_VOP_ELOCKED(vp, "vgonel");
2714 ASSERT_VI_LOCKED(vp, "vgonel");
2715 VNASSERT(vp->v_holdcnt, vp,
2716 ("vgonel: vp %p has no reference.", vp));
2717 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2718 td = curthread;
2719
2720 /*
2721 * Don't vgonel if we're already doomed.
2722 */
2723 if (vp->v_iflag & VI_DOOMED)
2724 return;
2725 vp->v_iflag |= VI_DOOMED;
2726
2727 /*
2728 * Check to see if the vnode is in use. If so, we have to call
2729 * VOP_CLOSE() and VOP_INACTIVE().
2730 */
2731 active = vp->v_usecount;
2732 oweinact = (vp->v_iflag & VI_OWEINACT);
2733 VI_UNLOCK(vp);
2734 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
2735
2736 /*
2737 * Clean out any buffers associated with the vnode.
2738 * If the flush fails, just toss the buffers.
2739 */
2740 mp = NULL;
2741 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2742 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2743 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0)
2744 vinvalbuf(vp, 0, 0, 0);
2745
2746 /*
2747 * If purging an active vnode, it must be closed and
2748 * deactivated before being reclaimed.
2749 */
2750 if (active)
2751 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2752 if (oweinact || active) {
2753 VI_LOCK(vp);
2754 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2755 vinactive(vp, td);
2756 VI_UNLOCK(vp);
2757 }
2758 if (vp->v_type == VSOCK)
2759 vfs_unp_reclaim(vp);
2760 /*
2761 * Reclaim the vnode.
2762 */
2763 if (VOP_RECLAIM(vp, td))
2764 panic("vgone: cannot reclaim");
2765 if (mp != NULL)
2766 vn_finished_secondary_write(mp);
2767 VNASSERT(vp->v_object == NULL, vp,
2768 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2769 /*
2770 * Clear the advisory locks and wake up waiting threads.
2771 */
2772 (void)VOP_ADVLOCKPURGE(vp);
2773 /*
2774 * Delete from old mount point vnode list.
2775 */
2776 delmntque(vp);
2777 cache_purge(vp);
2778 /*
2779 * Done with purge, reset to the standard lock and invalidate
2780 * the vnode.
2781 */
2782 VI_LOCK(vp);
2783 vp->v_vnlock = &vp->v_lock;
2784 vp->v_op = &dead_vnodeops;
2785 vp->v_tag = "none";
2786 vp->v_type = VBAD;
2787 }
2788
2789 /*
2790 * Calculate the total number of references to a special device.
2791 */
2792 int
2793 vcount(struct vnode *vp)
2794 {
2795 int count;
2796
2797 dev_lock();
2798 count = vp->v_rdev->si_usecount;
2799 dev_unlock();
2800 return (count);
2801 }
2802
2803 /*
2804 * Same as above, but using the struct cdev *as argument
2805 */
2806 int
2807 count_dev(struct cdev *dev)
2808 {
2809 int count;
2810
2811 dev_lock();
2812 count = dev->si_usecount;
2813 dev_unlock();
2814 return(count);
2815 }
2816
2817 /*
2818 * Print out a description of a vnode.
2819 */
2820 static char *typename[] =
2821 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2822 "VMARKER"};
2823
2824 void
2825 vn_printf(struct vnode *vp, const char *fmt, ...)
2826 {
2827 va_list ap;
2828 char buf[256], buf2[16];
2829 u_long flags;
2830
2831 va_start(ap, fmt);
2832 vprintf(fmt, ap);
2833 va_end(ap);
2834 printf("%p: ", (void *)vp);
2835 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2836 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2837 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2838 buf[0] = '\0';
2839 buf[1] = '\0';
2840 if (vp->v_vflag & VV_ROOT)
2841 strlcat(buf, "|VV_ROOT", sizeof(buf));
2842 if (vp->v_vflag & VV_ISTTY)
2843 strlcat(buf, "|VV_ISTTY", sizeof(buf));
2844 if (vp->v_vflag & VV_NOSYNC)
2845 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
2846 if (vp->v_vflag & VV_ETERNALDEV)
2847 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
2848 if (vp->v_vflag & VV_CACHEDLABEL)
2849 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
2850 if (vp->v_vflag & VV_TEXT)
2851 strlcat(buf, "|VV_TEXT", sizeof(buf));
2852 if (vp->v_vflag & VV_COPYONWRITE)
2853 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
2854 if (vp->v_vflag & VV_SYSTEM)
2855 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
2856 if (vp->v_vflag & VV_PROCDEP)
2857 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
2858 if (vp->v_vflag & VV_NOKNOTE)
2859 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
2860 if (vp->v_vflag & VV_DELETED)
2861 strlcat(buf, "|VV_DELETED", sizeof(buf));
2862 if (vp->v_vflag & VV_MD)
2863 strlcat(buf, "|VV_MD", sizeof(buf));
2864 if (vp->v_vflag & VV_FORCEINSMQ)
2865 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
2866 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
2867 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
2868 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ);
2869 if (flags != 0) {
2870 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
2871 strlcat(buf, buf2, sizeof(buf));
2872 }
2873 if (vp->v_iflag & VI_MOUNT)
2874 strlcat(buf, "|VI_MOUNT", sizeof(buf));
2875 if (vp->v_iflag & VI_AGE)
2876 strlcat(buf, "|VI_AGE", sizeof(buf));
2877 if (vp->v_iflag & VI_DOOMED)
2878 strlcat(buf, "|VI_DOOMED", sizeof(buf));
2879 if (vp->v_iflag & VI_FREE)
2880 strlcat(buf, "|VI_FREE", sizeof(buf));
2881 if (vp->v_iflag & VI_ACTIVE)
2882 strlcat(buf, "|VI_ACTIVE", sizeof(buf));
2883 if (vp->v_iflag & VI_DOINGINACT)
2884 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
2885 if (vp->v_iflag & VI_OWEINACT)
2886 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
2887 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE |
2888 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT);
2889 if (flags != 0) {
2890 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
2891 strlcat(buf, buf2, sizeof(buf));
2892 }
2893 printf(" flags (%s)\n", buf + 1);
2894 if (mtx_owned(VI_MTX(vp)))
2895 printf(" VI_LOCKed");
2896 if (vp->v_object != NULL)
2897 printf(" v_object %p ref %d pages %d "
2898 "cleanbuf %d dirtybuf %d\n",
2899 vp->v_object, vp->v_object->ref_count,
2900 vp->v_object->resident_page_count,
2901 vp->v_bufobj.bo_dirty.bv_cnt,
2902 vp->v_bufobj.bo_clean.bv_cnt);
2903 printf(" ");
2904 lockmgr_printinfo(vp->v_vnlock);
2905 if (vp->v_data != NULL)
2906 VOP_PRINT(vp);
2907 }
2908
2909 #ifdef DDB
2910 /*
2911 * List all of the locked vnodes in the system.
2912 * Called when debugging the kernel.
2913 */
2914 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2915 {
2916 struct mount *mp;
2917 struct vnode *vp;
2918
2919 /*
2920 * Note: because this is DDB, we can't obey the locking semantics
2921 * for these structures, which means we could catch an inconsistent
2922 * state and dereference a nasty pointer. Not much to be done
2923 * about that.
2924 */
2925 db_printf("Locked vnodes\n");
2926 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2927 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2928 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
2929 vprint("", vp);
2930 }
2931 }
2932 }
2933
2934 /*
2935 * Show details about the given vnode.
2936 */
2937 DB_SHOW_COMMAND(vnode, db_show_vnode)
2938 {
2939 struct vnode *vp;
2940
2941 if (!have_addr)
2942 return;
2943 vp = (struct vnode *)addr;
2944 vn_printf(vp, "vnode ");
2945 }
2946
2947 /*
2948 * Show details about the given mount point.
2949 */
2950 DB_SHOW_COMMAND(mount, db_show_mount)
2951 {
2952 struct mount *mp;
2953 struct vfsopt *opt;
2954 struct statfs *sp;
2955 struct vnode *vp;
2956 char buf[512];
2957 uint64_t mflags;
2958 u_int flags;
2959
2960 if (!have_addr) {
2961 /* No address given, print short info about all mount points. */
2962 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2963 db_printf("%p %s on %s (%s)\n", mp,
2964 mp->mnt_stat.f_mntfromname,
2965 mp->mnt_stat.f_mntonname,
2966 mp->mnt_stat.f_fstypename);
2967 if (db_pager_quit)
2968 break;
2969 }
2970 db_printf("\nMore info: show mount <addr>\n");
2971 return;
2972 }
2973
2974 mp = (struct mount *)addr;
2975 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
2976 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
2977
2978 buf[0] = '\0';
2979 mflags = mp->mnt_flag;
2980 #define MNT_FLAG(flag) do { \
2981 if (mflags & (flag)) { \
2982 if (buf[0] != '\0') \
2983 strlcat(buf, ", ", sizeof(buf)); \
2984 strlcat(buf, (#flag) + 4, sizeof(buf)); \
2985 mflags &= ~(flag); \
2986 } \
2987 } while (0)
2988 MNT_FLAG(MNT_RDONLY);
2989 MNT_FLAG(MNT_SYNCHRONOUS);
2990 MNT_FLAG(MNT_NOEXEC);
2991 MNT_FLAG(MNT_NOSUID);
2992 MNT_FLAG(MNT_NFS4ACLS);
2993 MNT_FLAG(MNT_UNION);
2994 MNT_FLAG(MNT_ASYNC);
2995 MNT_FLAG(MNT_SUIDDIR);
2996 MNT_FLAG(MNT_SOFTDEP);
2997 MNT_FLAG(MNT_NOSYMFOLLOW);
2998 MNT_FLAG(MNT_GJOURNAL);
2999 MNT_FLAG(MNT_MULTILABEL);
3000 MNT_FLAG(MNT_ACLS);
3001 MNT_FLAG(MNT_NOATIME);
3002 MNT_FLAG(MNT_NOCLUSTERR);
3003 MNT_FLAG(MNT_NOCLUSTERW);
3004 MNT_FLAG(MNT_SUJ);
3005 MNT_FLAG(MNT_EXRDONLY);
3006 MNT_FLAG(MNT_EXPORTED);
3007 MNT_FLAG(MNT_DEFEXPORTED);
3008 MNT_FLAG(MNT_EXPORTANON);
3009 MNT_FLAG(MNT_EXKERB);
3010 MNT_FLAG(MNT_EXPUBLIC);
3011 MNT_FLAG(MNT_LOCAL);
3012 MNT_FLAG(MNT_QUOTA);
3013 MNT_FLAG(MNT_ROOTFS);
3014 MNT_FLAG(MNT_USER);
3015 MNT_FLAG(MNT_IGNORE);
3016 MNT_FLAG(MNT_UPDATE);
3017 MNT_FLAG(MNT_DELEXPORT);
3018 MNT_FLAG(MNT_RELOAD);
3019 MNT_FLAG(MNT_FORCE);
3020 MNT_FLAG(MNT_SNAPSHOT);
3021 MNT_FLAG(MNT_BYFSID);
3022 #undef MNT_FLAG
3023 if (mflags != 0) {
3024 if (buf[0] != '\0')
3025 strlcat(buf, ", ", sizeof(buf));
3026 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3027 "0x%016jx", mflags);
3028 }
3029 db_printf(" mnt_flag = %s\n", buf);
3030
3031 buf[0] = '\0';
3032 flags = mp->mnt_kern_flag;
3033 #define MNT_KERN_FLAG(flag) do { \
3034 if (flags & (flag)) { \
3035 if (buf[0] != '\0') \
3036 strlcat(buf, ", ", sizeof(buf)); \
3037 strlcat(buf, (#flag) + 5, sizeof(buf)); \
3038 flags &= ~(flag); \
3039 } \
3040 } while (0)
3041 MNT_KERN_FLAG(MNTK_UNMOUNTF);
3042 MNT_KERN_FLAG(MNTK_ASYNC);
3043 MNT_KERN_FLAG(MNTK_SOFTDEP);
3044 MNT_KERN_FLAG(MNTK_NOINSMNTQ);
3045 MNT_KERN_FLAG(MNTK_DRAINING);
3046 MNT_KERN_FLAG(MNTK_REFEXPIRE);
3047 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
3048 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
3049 MNT_KERN_FLAG(MNTK_NO_IOPF);
3050 MNT_KERN_FLAG(MNTK_VGONE_UPPER);
3051 MNT_KERN_FLAG(MNTK_VGONE_WAITER);
3052 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT);
3053 MNT_KERN_FLAG(MNTK_MARKER);
3054 MNT_KERN_FLAG(MNTK_NOASYNC);
3055 MNT_KERN_FLAG(MNTK_UNMOUNT);
3056 MNT_KERN_FLAG(MNTK_MWAIT);
3057 MNT_KERN_FLAG(MNTK_SUSPEND);
3058 MNT_KERN_FLAG(MNTK_SUSPEND2);
3059 MNT_KERN_FLAG(MNTK_SUSPENDED);
3060 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
3061 MNT_KERN_FLAG(MNTK_NOKNOTE);
3062 #undef MNT_KERN_FLAG
3063 if (flags != 0) {
3064 if (buf[0] != '\0')
3065 strlcat(buf, ", ", sizeof(buf));
3066 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3067 "0x%08x", flags);
3068 }
3069 db_printf(" mnt_kern_flag = %s\n", buf);
3070
3071 db_printf(" mnt_opt = ");
3072 opt = TAILQ_FIRST(mp->mnt_opt);
3073 if (opt != NULL) {
3074 db_printf("%s", opt->name);
3075 opt = TAILQ_NEXT(opt, link);
3076 while (opt != NULL) {
3077 db_printf(", %s", opt->name);
3078 opt = TAILQ_NEXT(opt, link);
3079 }
3080 }
3081 db_printf("\n");
3082
3083 sp = &mp->mnt_stat;
3084 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
3085 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
3086 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
3087 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
3088 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
3089 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
3090 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
3091 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
3092 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
3093 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
3094 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
3095 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
3096
3097 db_printf(" mnt_cred = { uid=%u ruid=%u",
3098 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
3099 if (jailed(mp->mnt_cred))
3100 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
3101 db_printf(" }\n");
3102 db_printf(" mnt_ref = %d\n", mp->mnt_ref);
3103 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
3104 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
3105 db_printf(" mnt_activevnodelistsize = %d\n",
3106 mp->mnt_activevnodelistsize);
3107 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
3108 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
3109 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
3110 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
3111 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
3112 db_printf(" mnt_secondary_accwrites = %d\n",
3113 mp->mnt_secondary_accwrites);
3114 db_printf(" mnt_gjprovider = %s\n",
3115 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
3116
3117 db_printf("\n\nList of active vnodes\n");
3118 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
3119 if (vp->v_type != VMARKER) {
3120 vn_printf(vp, "vnode ");
3121 if (db_pager_quit)
3122 break;
3123 }
3124 }
3125 db_printf("\n\nList of inactive vnodes\n");
3126 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3127 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
3128 vn_printf(vp, "vnode ");
3129 if (db_pager_quit)
3130 break;
3131 }
3132 }
3133 }
3134 #endif /* DDB */
3135
3136 /*
3137 * Fill in a struct xvfsconf based on a struct vfsconf.
3138 */
3139 static int
3140 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
3141 {
3142 struct xvfsconf xvfsp;
3143
3144 bzero(&xvfsp, sizeof(xvfsp));
3145 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3146 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3147 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3148 xvfsp.vfc_flags = vfsp->vfc_flags;
3149 /*
3150 * These are unused in userland, we keep them
3151 * to not break binary compatibility.
3152 */
3153 xvfsp.vfc_vfsops = NULL;
3154 xvfsp.vfc_next = NULL;
3155 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3156 }
3157
3158 #ifdef COMPAT_FREEBSD32
3159 struct xvfsconf32 {
3160 uint32_t vfc_vfsops;
3161 char vfc_name[MFSNAMELEN];
3162 int32_t vfc_typenum;
3163 int32_t vfc_refcount;
3164 int32_t vfc_flags;
3165 uint32_t vfc_next;
3166 };
3167
3168 static int
3169 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
3170 {
3171 struct xvfsconf32 xvfsp;
3172
3173 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3174 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3175 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3176 xvfsp.vfc_flags = vfsp->vfc_flags;
3177 xvfsp.vfc_vfsops = 0;
3178 xvfsp.vfc_next = 0;
3179 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3180 }
3181 #endif
3182
3183 /*
3184 * Top level filesystem related information gathering.
3185 */
3186 static int
3187 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
3188 {
3189 struct vfsconf *vfsp;
3190 int error;
3191
3192 error = 0;
3193 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3194 #ifdef COMPAT_FREEBSD32
3195 if (req->flags & SCTL_MASK32)
3196 error = vfsconf2x32(req, vfsp);
3197 else
3198 #endif
3199 error = vfsconf2x(req, vfsp);
3200 if (error)
3201 break;
3202 }
3203 return (error);
3204 }
3205
3206 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD,
3207 NULL, 0, sysctl_vfs_conflist,
3208 "S,xvfsconf", "List of all configured filesystems");
3209
3210 #ifndef BURN_BRIDGES
3211 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
3212
3213 static int
3214 vfs_sysctl(SYSCTL_HANDLER_ARGS)
3215 {
3216 int *name = (int *)arg1 - 1; /* XXX */
3217 u_int namelen = arg2 + 1; /* XXX */
3218 struct vfsconf *vfsp;
3219
3220 log(LOG_WARNING, "userland calling deprecated sysctl, "
3221 "please rebuild world\n");
3222
3223 #if 1 || defined(COMPAT_PRELITE2)
3224 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
3225 if (namelen == 1)
3226 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
3227 #endif
3228
3229 switch (name[1]) {
3230 case VFS_MAXTYPENUM:
3231 if (namelen != 2)
3232 return (ENOTDIR);
3233 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
3234 case VFS_CONF:
3235 if (namelen != 3)
3236 return (ENOTDIR); /* overloaded */
3237 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
3238 if (vfsp->vfc_typenum == name[2])
3239 break;
3240 if (vfsp == NULL)
3241 return (EOPNOTSUPP);
3242 #ifdef COMPAT_FREEBSD32
3243 if (req->flags & SCTL_MASK32)
3244 return (vfsconf2x32(req, vfsp));
3245 else
3246 #endif
3247 return (vfsconf2x(req, vfsp));
3248 }
3249 return (EOPNOTSUPP);
3250 }
3251
3252 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
3253 vfs_sysctl, "Generic filesystem");
3254
3255 #if 1 || defined(COMPAT_PRELITE2)
3256
3257 static int
3258 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
3259 {
3260 int error;
3261 struct vfsconf *vfsp;
3262 struct ovfsconf ovfs;
3263
3264 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3265 bzero(&ovfs, sizeof(ovfs));
3266 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
3267 strcpy(ovfs.vfc_name, vfsp->vfc_name);
3268 ovfs.vfc_index = vfsp->vfc_typenum;
3269 ovfs.vfc_refcount = vfsp->vfc_refcount;
3270 ovfs.vfc_flags = vfsp->vfc_flags;
3271 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
3272 if (error)
3273 return error;
3274 }
3275 return 0;
3276 }
3277
3278 #endif /* 1 || COMPAT_PRELITE2 */
3279 #endif /* !BURN_BRIDGES */
3280
3281 #define KINFO_VNODESLOP 10
3282 #ifdef notyet
3283 /*
3284 * Dump vnode list (via sysctl).
3285 */
3286 /* ARGSUSED */
3287 static int
3288 sysctl_vnode(SYSCTL_HANDLER_ARGS)
3289 {
3290 struct xvnode *xvn;
3291 struct mount *mp;
3292 struct vnode *vp;
3293 int error, len, n;
3294
3295 /*
3296 * Stale numvnodes access is not fatal here.
3297 */
3298 req->lock = 0;
3299 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
3300 if (!req->oldptr)
3301 /* Make an estimate */
3302 return (SYSCTL_OUT(req, 0, len));
3303
3304 error = sysctl_wire_old_buffer(req, 0);
3305 if (error != 0)
3306 return (error);
3307 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
3308 n = 0;
3309 mtx_lock(&mountlist_mtx);
3310 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3311 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
3312 continue;
3313 MNT_ILOCK(mp);
3314 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3315 if (n == len)
3316 break;
3317 vref(vp);
3318 xvn[n].xv_size = sizeof *xvn;
3319 xvn[n].xv_vnode = vp;
3320 xvn[n].xv_id = 0; /* XXX compat */
3321 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
3322 XV_COPY(usecount);
3323 XV_COPY(writecount);
3324 XV_COPY(holdcnt);
3325 XV_COPY(mount);
3326 XV_COPY(numoutput);
3327 XV_COPY(type);
3328 #undef XV_COPY
3329 xvn[n].xv_flag = vp->v_vflag;
3330
3331 switch (vp->v_type) {
3332 case VREG:
3333 case VDIR:
3334 case VLNK:
3335 break;
3336 case VBLK:
3337 case VCHR:
3338 if (vp->v_rdev == NULL) {
3339 vrele(vp);
3340 continue;
3341 }
3342 xvn[n].xv_dev = dev2udev(vp->v_rdev);
3343 break;
3344 case VSOCK:
3345 xvn[n].xv_socket = vp->v_socket;
3346 break;
3347 case VFIFO:
3348 xvn[n].xv_fifo = vp->v_fifoinfo;
3349 break;
3350 case VNON:
3351 case VBAD:
3352 default:
3353 /* shouldn't happen? */
3354 vrele(vp);
3355 continue;
3356 }
3357 vrele(vp);
3358 ++n;
3359 }
3360 MNT_IUNLOCK(mp);
3361 mtx_lock(&mountlist_mtx);
3362 vfs_unbusy(mp);
3363 if (n == len)
3364 break;
3365 }
3366 mtx_unlock(&mountlist_mtx);
3367
3368 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
3369 free(xvn, M_TEMP);
3370 return (error);
3371 }
3372
3373 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
3374 0, 0, sysctl_vnode, "S,xvnode", "");
3375 #endif
3376
3377 /*
3378 * Unmount all filesystems. The list is traversed in reverse order
3379 * of mounting to avoid dependencies.
3380 */
3381 void
3382 vfs_unmountall(void)
3383 {
3384 struct mount *mp;
3385 struct thread *td;
3386 int error;
3387
3388 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
3389 td = curthread;
3390
3391 /*
3392 * Since this only runs when rebooting, it is not interlocked.
3393 */
3394 while(!TAILQ_EMPTY(&mountlist)) {
3395 mp = TAILQ_LAST(&mountlist, mntlist);
3396 error = dounmount(mp, MNT_FORCE, td);
3397 if (error) {
3398 TAILQ_REMOVE(&mountlist, mp, mnt_list);
3399 /*
3400 * XXX: Due to the way in which we mount the root
3401 * file system off of devfs, devfs will generate a
3402 * "busy" warning when we try to unmount it before
3403 * the root. Don't print a warning as a result in
3404 * order to avoid false positive errors that may
3405 * cause needless upset.
3406 */
3407 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
3408 printf("unmount of %s failed (",
3409 mp->mnt_stat.f_mntonname);
3410 if (error == EBUSY)
3411 printf("BUSY)\n");
3412 else
3413 printf("%d)\n", error);
3414 }
3415 } else {
3416 /* The unmount has removed mp from the mountlist */
3417 }
3418 }
3419 }
3420
3421 /*
3422 * perform msync on all vnodes under a mount point
3423 * the mount point must be locked.
3424 */
3425 void
3426 vfs_msync(struct mount *mp, int flags)
3427 {
3428 struct vnode *vp, *mvp;
3429 struct vm_object *obj;
3430
3431 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
3432 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
3433 obj = vp->v_object;
3434 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
3435 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
3436 if (!vget(vp,
3437 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
3438 curthread)) {
3439 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
3440 vput(vp);
3441 continue;
3442 }
3443
3444 obj = vp->v_object;
3445 if (obj != NULL) {
3446 VM_OBJECT_WLOCK(obj);
3447 vm_object_page_clean(obj, 0, 0,
3448 flags == MNT_WAIT ?
3449 OBJPC_SYNC : OBJPC_NOSYNC);
3450 VM_OBJECT_WUNLOCK(obj);
3451 }
3452 vput(vp);
3453 }
3454 } else
3455 VI_UNLOCK(vp);
3456 }
3457 }
3458
3459 static void
3460 destroy_vpollinfo_free(struct vpollinfo *vi)
3461 {
3462
3463 knlist_destroy(&vi->vpi_selinfo.si_note);
3464 mtx_destroy(&vi->vpi_lock);
3465 uma_zfree(vnodepoll_zone, vi);
3466 }
3467
3468 static void
3469 destroy_vpollinfo(struct vpollinfo *vi)
3470 {
3471
3472 knlist_clear(&vi->vpi_selinfo.si_note, 1);
3473 seldrain(&vi->vpi_selinfo);
3474 destroy_vpollinfo_free(vi);
3475 }
3476
3477 /*
3478 * Initalize per-vnode helper structure to hold poll-related state.
3479 */
3480 void
3481 v_addpollinfo(struct vnode *vp)
3482 {
3483 struct vpollinfo *vi;
3484
3485 if (vp->v_pollinfo != NULL)
3486 return;
3487 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
3488 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
3489 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
3490 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
3491 VI_LOCK(vp);
3492 if (vp->v_pollinfo != NULL) {
3493 VI_UNLOCK(vp);
3494 destroy_vpollinfo_free(vi);
3495 return;
3496 }
3497 vp->v_pollinfo = vi;
3498 VI_UNLOCK(vp);
3499 }
3500
3501 /*
3502 * Record a process's interest in events which might happen to
3503 * a vnode. Because poll uses the historic select-style interface
3504 * internally, this routine serves as both the ``check for any
3505 * pending events'' and the ``record my interest in future events''
3506 * functions. (These are done together, while the lock is held,
3507 * to avoid race conditions.)
3508 */
3509 int
3510 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3511 {
3512
3513 v_addpollinfo(vp);
3514 mtx_lock(&vp->v_pollinfo->vpi_lock);
3515 if (vp->v_pollinfo->vpi_revents & events) {
3516 /*
3517 * This leaves events we are not interested
3518 * in available for the other process which
3519 * which presumably had requested them
3520 * (otherwise they would never have been
3521 * recorded).
3522 */
3523 events &= vp->v_pollinfo->vpi_revents;
3524 vp->v_pollinfo->vpi_revents &= ~events;
3525
3526 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3527 return (events);
3528 }
3529 vp->v_pollinfo->vpi_events |= events;
3530 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3531 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3532 return (0);
3533 }
3534
3535 /*
3536 * Routine to create and manage a filesystem syncer vnode.
3537 */
3538 #define sync_close ((int (*)(struct vop_close_args *))nullop)
3539 static int sync_fsync(struct vop_fsync_args *);
3540 static int sync_inactive(struct vop_inactive_args *);
3541 static int sync_reclaim(struct vop_reclaim_args *);
3542
3543 static struct vop_vector sync_vnodeops = {
3544 .vop_bypass = VOP_EOPNOTSUPP,
3545 .vop_close = sync_close, /* close */
3546 .vop_fsync = sync_fsync, /* fsync */
3547 .vop_inactive = sync_inactive, /* inactive */
3548 .vop_reclaim = sync_reclaim, /* reclaim */
3549 .vop_lock1 = vop_stdlock, /* lock */
3550 .vop_unlock = vop_stdunlock, /* unlock */
3551 .vop_islocked = vop_stdislocked, /* islocked */
3552 };
3553
3554 /*
3555 * Create a new filesystem syncer vnode for the specified mount point.
3556 */
3557 void
3558 vfs_allocate_syncvnode(struct mount *mp)
3559 {
3560 struct vnode *vp;
3561 struct bufobj *bo;
3562 static long start, incr, next;
3563 int error;
3564
3565 /* Allocate a new vnode */
3566 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
3567 if (error != 0)
3568 panic("vfs_allocate_syncvnode: getnewvnode() failed");
3569 vp->v_type = VNON;
3570 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3571 vp->v_vflag |= VV_FORCEINSMQ;
3572 error = insmntque(vp, mp);
3573 if (error != 0)
3574 panic("vfs_allocate_syncvnode: insmntque() failed");
3575 vp->v_vflag &= ~VV_FORCEINSMQ;
3576 VOP_UNLOCK(vp, 0);
3577 /*
3578 * Place the vnode onto the syncer worklist. We attempt to
3579 * scatter them about on the list so that they will go off
3580 * at evenly distributed times even if all the filesystems
3581 * are mounted at once.
3582 */
3583 next += incr;
3584 if (next == 0 || next > syncer_maxdelay) {
3585 start /= 2;
3586 incr /= 2;
3587 if (start == 0) {
3588 start = syncer_maxdelay / 2;
3589 incr = syncer_maxdelay;
3590 }
3591 next = start;
3592 }
3593 bo = &vp->v_bufobj;
3594 BO_LOCK(bo);
3595 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
3596 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
3597 mtx_lock(&sync_mtx);
3598 sync_vnode_count++;
3599 if (mp->mnt_syncer == NULL) {
3600 mp->mnt_syncer = vp;
3601 vp = NULL;
3602 }
3603 mtx_unlock(&sync_mtx);
3604 BO_UNLOCK(bo);
3605 if (vp != NULL) {
3606 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3607 vgone(vp);
3608 vput(vp);
3609 }
3610 }
3611
3612 void
3613 vfs_deallocate_syncvnode(struct mount *mp)
3614 {
3615 struct vnode *vp;
3616
3617 mtx_lock(&sync_mtx);
3618 vp = mp->mnt_syncer;
3619 if (vp != NULL)
3620 mp->mnt_syncer = NULL;
3621 mtx_unlock(&sync_mtx);
3622 if (vp != NULL)
3623 vrele(vp);
3624 }
3625
3626 /*
3627 * Do a lazy sync of the filesystem.
3628 */
3629 static int
3630 sync_fsync(struct vop_fsync_args *ap)
3631 {
3632 struct vnode *syncvp = ap->a_vp;
3633 struct mount *mp = syncvp->v_mount;
3634 int error, save;
3635 struct bufobj *bo;
3636
3637 /*
3638 * We only need to do something if this is a lazy evaluation.
3639 */
3640 if (ap->a_waitfor != MNT_LAZY)
3641 return (0);
3642
3643 /*
3644 * Move ourselves to the back of the sync list.
3645 */
3646 bo = &syncvp->v_bufobj;
3647 BO_LOCK(bo);
3648 vn_syncer_add_to_worklist(bo, syncdelay);
3649 BO_UNLOCK(bo);
3650
3651 /*
3652 * Walk the list of vnodes pushing all that are dirty and
3653 * not already on the sync list.
3654 */
3655 mtx_lock(&mountlist_mtx);
3656 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
3657 mtx_unlock(&mountlist_mtx);
3658 return (0);
3659 }
3660 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
3661 vfs_unbusy(mp);
3662 return (0);
3663 }
3664 save = curthread_pflags_set(TDP_SYNCIO);
3665 vfs_msync(mp, MNT_NOWAIT);
3666 error = VFS_SYNC(mp, MNT_LAZY);
3667 curthread_pflags_restore(save);
3668 vn_finished_write(mp);
3669 vfs_unbusy(mp);
3670 return (error);
3671 }
3672
3673 /*
3674 * The syncer vnode is no referenced.
3675 */
3676 static int
3677 sync_inactive(struct vop_inactive_args *ap)
3678 {
3679
3680 vgone(ap->a_vp);
3681 return (0);
3682 }
3683
3684 /*
3685 * The syncer vnode is no longer needed and is being decommissioned.
3686 *
3687 * Modifications to the worklist must be protected by sync_mtx.
3688 */
3689 static int
3690 sync_reclaim(struct vop_reclaim_args *ap)
3691 {
3692 struct vnode *vp = ap->a_vp;
3693 struct bufobj *bo;
3694
3695 bo = &vp->v_bufobj;
3696 BO_LOCK(bo);
3697 mtx_lock(&sync_mtx);
3698 if (vp->v_mount->mnt_syncer == vp)
3699 vp->v_mount->mnt_syncer = NULL;
3700 if (bo->bo_flag & BO_ONWORKLST) {
3701 LIST_REMOVE(bo, bo_synclist);
3702 syncer_worklist_len--;
3703 sync_vnode_count--;
3704 bo->bo_flag &= ~BO_ONWORKLST;
3705 }
3706 mtx_unlock(&sync_mtx);
3707 BO_UNLOCK(bo);
3708
3709 return (0);
3710 }
3711
3712 /*
3713 * Check if vnode represents a disk device
3714 */
3715 int
3716 vn_isdisk(struct vnode *vp, int *errp)
3717 {
3718 int error;
3719
3720 error = 0;
3721 dev_lock();
3722 if (vp->v_type != VCHR)
3723 error = ENOTBLK;
3724 else if (vp->v_rdev == NULL)
3725 error = ENXIO;
3726 else if (vp->v_rdev->si_devsw == NULL)
3727 error = ENXIO;
3728 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
3729 error = ENOTBLK;
3730 dev_unlock();
3731 if (errp != NULL)
3732 *errp = error;
3733 return (error == 0);
3734 }
3735
3736 /*
3737 * Common filesystem object access control check routine. Accepts a
3738 * vnode's type, "mode", uid and gid, requested access mode, credentials,
3739 * and optional call-by-reference privused argument allowing vaccess()
3740 * to indicate to the caller whether privilege was used to satisfy the
3741 * request (obsoleted). Returns 0 on success, or an errno on failure.
3742 */
3743 int
3744 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
3745 accmode_t accmode, struct ucred *cred, int *privused)
3746 {
3747 accmode_t dac_granted;
3748 accmode_t priv_granted;
3749
3750 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
3751 ("invalid bit in accmode"));
3752 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
3753 ("VAPPEND without VWRITE"));
3754
3755 /*
3756 * Look for a normal, non-privileged way to access the file/directory
3757 * as requested. If it exists, go with that.
3758 */
3759
3760 if (privused != NULL)
3761 *privused = 0;
3762
3763 dac_granted = 0;
3764
3765 /* Check the owner. */
3766 if (cred->cr_uid == file_uid) {
3767 dac_granted |= VADMIN;
3768 if (file_mode & S_IXUSR)
3769 dac_granted |= VEXEC;
3770 if (file_mode & S_IRUSR)
3771 dac_granted |= VREAD;
3772 if (file_mode & S_IWUSR)
3773 dac_granted |= (VWRITE | VAPPEND);
3774
3775 if ((accmode & dac_granted) == accmode)
3776 return (0);
3777
3778 goto privcheck;
3779 }
3780
3781 /* Otherwise, check the groups (first match) */
3782 if (groupmember(file_gid, cred)) {
3783 if (file_mode & S_IXGRP)
3784 dac_granted |= VEXEC;
3785 if (file_mode & S_IRGRP)
3786 dac_granted |= VREAD;
3787 if (file_mode & S_IWGRP)
3788 dac_granted |= (VWRITE | VAPPEND);
3789
3790 if ((accmode & dac_granted) == accmode)
3791 return (0);
3792
3793 goto privcheck;
3794 }
3795
3796 /* Otherwise, check everyone else. */
3797 if (file_mode & S_IXOTH)
3798 dac_granted |= VEXEC;
3799 if (file_mode & S_IROTH)
3800 dac_granted |= VREAD;
3801 if (file_mode & S_IWOTH)
3802 dac_granted |= (VWRITE | VAPPEND);
3803 if ((accmode & dac_granted) == accmode)
3804 return (0);
3805
3806 privcheck:
3807 /*
3808 * Build a privilege mask to determine if the set of privileges
3809 * satisfies the requirements when combined with the granted mask
3810 * from above. For each privilege, if the privilege is required,
3811 * bitwise or the request type onto the priv_granted mask.
3812 */
3813 priv_granted = 0;
3814
3815 if (type == VDIR) {
3816 /*
3817 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
3818 * requests, instead of PRIV_VFS_EXEC.
3819 */
3820 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3821 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
3822 priv_granted |= VEXEC;
3823 } else {
3824 /*
3825 * Ensure that at least one execute bit is on. Otherwise,
3826 * a privileged user will always succeed, and we don't want
3827 * this to happen unless the file really is executable.
3828 */
3829 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3830 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
3831 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
3832 priv_granted |= VEXEC;
3833 }
3834
3835 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
3836 !priv_check_cred(cred, PRIV_VFS_READ, 0))
3837 priv_granted |= VREAD;
3838
3839 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
3840 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
3841 priv_granted |= (VWRITE | VAPPEND);
3842
3843 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
3844 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
3845 priv_granted |= VADMIN;
3846
3847 if ((accmode & (priv_granted | dac_granted)) == accmode) {
3848 /* XXX audit: privilege used */
3849 if (privused != NULL)
3850 *privused = 1;
3851 return (0);
3852 }
3853
3854 return ((accmode & VADMIN) ? EPERM : EACCES);
3855 }
3856
3857 /*
3858 * Credential check based on process requesting service, and per-attribute
3859 * permissions.
3860 */
3861 int
3862 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
3863 struct thread *td, accmode_t accmode)
3864 {
3865
3866 /*
3867 * Kernel-invoked always succeeds.
3868 */
3869 if (cred == NOCRED)
3870 return (0);
3871
3872 /*
3873 * Do not allow privileged processes in jail to directly manipulate
3874 * system attributes.
3875 */
3876 switch (attrnamespace) {
3877 case EXTATTR_NAMESPACE_SYSTEM:
3878 /* Potentially should be: return (EPERM); */
3879 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
3880 case EXTATTR_NAMESPACE_USER:
3881 return (VOP_ACCESS(vp, accmode, cred, td));
3882 default:
3883 return (EPERM);
3884 }
3885 }
3886
3887 #ifdef DEBUG_VFS_LOCKS
3888 /*
3889 * This only exists to supress warnings from unlocked specfs accesses. It is
3890 * no longer ok to have an unlocked VFS.
3891 */
3892 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
3893 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
3894
3895 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
3896 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
3897 "Drop into debugger on lock violation");
3898
3899 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
3900 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
3901 0, "Check for interlock across VOPs");
3902
3903 int vfs_badlock_print = 1; /* Print lock violations. */
3904 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
3905 0, "Print lock violations");
3906
3907 #ifdef KDB
3908 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
3909 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
3910 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
3911 #endif
3912
3913 static void
3914 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
3915 {
3916
3917 #ifdef KDB
3918 if (vfs_badlock_backtrace)
3919 kdb_backtrace();
3920 #endif
3921 if (vfs_badlock_print)
3922 printf("%s: %p %s\n", str, (void *)vp, msg);
3923 if (vfs_badlock_ddb)
3924 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
3925 }
3926
3927 void
3928 assert_vi_locked(struct vnode *vp, const char *str)
3929 {
3930
3931 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
3932 vfs_badlock("interlock is not locked but should be", str, vp);
3933 }
3934
3935 void
3936 assert_vi_unlocked(struct vnode *vp, const char *str)
3937 {
3938
3939 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
3940 vfs_badlock("interlock is locked but should not be", str, vp);
3941 }
3942
3943 void
3944 assert_vop_locked(struct vnode *vp, const char *str)
3945 {
3946 int locked;
3947
3948 if (!IGNORE_LOCK(vp)) {
3949 locked = VOP_ISLOCKED(vp);
3950 if (locked == 0 || locked == LK_EXCLOTHER)
3951 vfs_badlock("is not locked but should be", str, vp);
3952 }
3953 }
3954
3955 void
3956 assert_vop_unlocked(struct vnode *vp, const char *str)
3957 {
3958
3959 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
3960 vfs_badlock("is locked but should not be", str, vp);
3961 }
3962
3963 void
3964 assert_vop_elocked(struct vnode *vp, const char *str)
3965 {
3966
3967 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
3968 vfs_badlock("is not exclusive locked but should be", str, vp);
3969 }
3970
3971 #if 0
3972 void
3973 assert_vop_elocked_other(struct vnode *vp, const char *str)
3974 {
3975
3976 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER)
3977 vfs_badlock("is not exclusive locked by another thread",
3978 str, vp);
3979 }
3980
3981 void
3982 assert_vop_slocked(struct vnode *vp, const char *str)
3983 {
3984
3985 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED)
3986 vfs_badlock("is not locked shared but should be", str, vp);
3987 }
3988 #endif /* 0 */
3989 #endif /* DEBUG_VFS_LOCKS */
3990
3991 void
3992 vop_rename_fail(struct vop_rename_args *ap)
3993 {
3994
3995 if (ap->a_tvp != NULL)
3996 vput(ap->a_tvp);
3997 if (ap->a_tdvp == ap->a_tvp)
3998 vrele(ap->a_tdvp);
3999 else
4000 vput(ap->a_tdvp);
4001 vrele(ap->a_fdvp);
4002 vrele(ap->a_fvp);
4003 }
4004
4005 void
4006 vop_rename_pre(void *ap)
4007 {
4008 struct vop_rename_args *a = ap;
4009
4010 #ifdef DEBUG_VFS_LOCKS
4011 if (a->a_tvp)
4012 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
4013 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
4014 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
4015 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
4016
4017 /* Check the source (from). */
4018 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
4019 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
4020 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
4021 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
4022 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
4023
4024 /* Check the target. */
4025 if (a->a_tvp)
4026 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
4027 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
4028 #endif
4029 if (a->a_tdvp != a->a_fdvp)
4030 vhold(a->a_fdvp);
4031 if (a->a_tvp != a->a_fvp)
4032 vhold(a->a_fvp);
4033 vhold(a->a_tdvp);
4034 if (a->a_tvp)
4035 vhold(a->a_tvp);
4036 }
4037
4038 void
4039 vop_strategy_pre(void *ap)
4040 {
4041 #ifdef DEBUG_VFS_LOCKS
4042 struct vop_strategy_args *a;
4043 struct buf *bp;
4044
4045 a = ap;
4046 bp = a->a_bp;
4047
4048 /*
4049 * Cluster ops lock their component buffers but not the IO container.
4050 */
4051 if ((bp->b_flags & B_CLUSTER) != 0)
4052 return;
4053
4054 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
4055 if (vfs_badlock_print)
4056 printf(
4057 "VOP_STRATEGY: bp is not locked but should be\n");
4058 if (vfs_badlock_ddb)
4059 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4060 }
4061 #endif
4062 }
4063
4064 void
4065 vop_lock_pre(void *ap)
4066 {
4067 #ifdef DEBUG_VFS_LOCKS
4068 struct vop_lock1_args *a = ap;
4069
4070 if ((a->a_flags & LK_INTERLOCK) == 0)
4071 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4072 else
4073 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
4074 #endif
4075 }
4076
4077 void
4078 vop_lock_post(void *ap, int rc)
4079 {
4080 #ifdef DEBUG_VFS_LOCKS
4081 struct vop_lock1_args *a = ap;
4082
4083 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4084 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
4085 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
4086 #endif
4087 }
4088
4089 void
4090 vop_unlock_pre(void *ap)
4091 {
4092 #ifdef DEBUG_VFS_LOCKS
4093 struct vop_unlock_args *a = ap;
4094
4095 if (a->a_flags & LK_INTERLOCK)
4096 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
4097 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
4098 #endif
4099 }
4100
4101 void
4102 vop_unlock_post(void *ap, int rc)
4103 {
4104 #ifdef DEBUG_VFS_LOCKS
4105 struct vop_unlock_args *a = ap;
4106
4107 if (a->a_flags & LK_INTERLOCK)
4108 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
4109 #endif
4110 }
4111
4112 void
4113 vop_create_post(void *ap, int rc)
4114 {
4115 struct vop_create_args *a = ap;
4116
4117 if (!rc)
4118 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4119 }
4120
4121 void
4122 vop_deleteextattr_post(void *ap, int rc)
4123 {
4124 struct vop_deleteextattr_args *a = ap;
4125
4126 if (!rc)
4127 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4128 }
4129
4130 void
4131 vop_link_post(void *ap, int rc)
4132 {
4133 struct vop_link_args *a = ap;
4134
4135 if (!rc) {
4136 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
4137 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
4138 }
4139 }
4140
4141 void
4142 vop_mkdir_post(void *ap, int rc)
4143 {
4144 struct vop_mkdir_args *a = ap;
4145
4146 if (!rc)
4147 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4148 }
4149
4150 void
4151 vop_mknod_post(void *ap, int rc)
4152 {
4153 struct vop_mknod_args *a = ap;
4154
4155 if (!rc)
4156 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4157 }
4158
4159 void
4160 vop_remove_post(void *ap, int rc)
4161 {
4162 struct vop_remove_args *a = ap;
4163
4164 if (!rc) {
4165 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4166 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4167 }
4168 }
4169
4170 void
4171 vop_rename_post(void *ap, int rc)
4172 {
4173 struct vop_rename_args *a = ap;
4174
4175 if (!rc) {
4176 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE);
4177 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE);
4178 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
4179 if (a->a_tvp)
4180 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
4181 }
4182 if (a->a_tdvp != a->a_fdvp)
4183 vdrop(a->a_fdvp);
4184 if (a->a_tvp != a->a_fvp)
4185 vdrop(a->a_fvp);
4186 vdrop(a->a_tdvp);
4187 if (a->a_tvp)
4188 vdrop(a->a_tvp);
4189 }
4190
4191 void
4192 vop_rmdir_post(void *ap, int rc)
4193 {
4194 struct vop_rmdir_args *a = ap;
4195
4196 if (!rc) {
4197 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4198 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4199 }
4200 }
4201
4202 void
4203 vop_setattr_post(void *ap, int rc)
4204 {
4205 struct vop_setattr_args *a = ap;
4206
4207 if (!rc)
4208 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4209 }
4210
4211 void
4212 vop_setextattr_post(void *ap, int rc)
4213 {
4214 struct vop_setextattr_args *a = ap;
4215
4216 if (!rc)
4217 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4218 }
4219
4220 void
4221 vop_symlink_post(void *ap, int rc)
4222 {
4223 struct vop_symlink_args *a = ap;
4224
4225 if (!rc)
4226 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4227 }
4228
4229 static struct knlist fs_knlist;
4230
4231 static void
4232 vfs_event_init(void *arg)
4233 {
4234 knlist_init_mtx(&fs_knlist, NULL);
4235 }
4236 /* XXX - correct order? */
4237 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
4238
4239 void
4240 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
4241 {
4242
4243 KNOTE_UNLOCKED(&fs_knlist, event);
4244 }
4245
4246 static int filt_fsattach(struct knote *kn);
4247 static void filt_fsdetach(struct knote *kn);
4248 static int filt_fsevent(struct knote *kn, long hint);
4249
4250 struct filterops fs_filtops = {
4251 .f_isfd = 0,
4252 .f_attach = filt_fsattach,
4253 .f_detach = filt_fsdetach,
4254 .f_event = filt_fsevent
4255 };
4256
4257 static int
4258 filt_fsattach(struct knote *kn)
4259 {
4260
4261 kn->kn_flags |= EV_CLEAR;
4262 knlist_add(&fs_knlist, kn, 0);
4263 return (0);
4264 }
4265
4266 static void
4267 filt_fsdetach(struct knote *kn)
4268 {
4269
4270 knlist_remove(&fs_knlist, kn, 0);
4271 }
4272
4273 static int
4274 filt_fsevent(struct knote *kn, long hint)
4275 {
4276
4277 kn->kn_fflags |= hint;
4278 return (kn->kn_fflags != 0);
4279 }
4280
4281 static int
4282 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
4283 {
4284 struct vfsidctl vc;
4285 int error;
4286 struct mount *mp;
4287
4288 error = SYSCTL_IN(req, &vc, sizeof(vc));
4289 if (error)
4290 return (error);
4291 if (vc.vc_vers != VFS_CTL_VERS1)
4292 return (EINVAL);
4293 mp = vfs_getvfs(&vc.vc_fsid);
4294 if (mp == NULL)
4295 return (ENOENT);
4296 /* ensure that a specific sysctl goes to the right filesystem. */
4297 if (strcmp(vc.vc_fstypename, "*") != 0 &&
4298 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
4299 vfs_rel(mp);
4300 return (EINVAL);
4301 }
4302 VCTLTOREQ(&vc, req);
4303 error = VFS_SYSCTL(mp, vc.vc_op, req);
4304 vfs_rel(mp);
4305 return (error);
4306 }
4307
4308 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
4309 NULL, 0, sysctl_vfs_ctl, "",
4310 "Sysctl by fsid");
4311
4312 /*
4313 * Function to initialize a va_filerev field sensibly.
4314 * XXX: Wouldn't a random number make a lot more sense ??
4315 */
4316 u_quad_t
4317 init_va_filerev(void)
4318 {
4319 struct bintime bt;
4320
4321 getbinuptime(&bt);
4322 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
4323 }
4324
4325 static int filt_vfsread(struct knote *kn, long hint);
4326 static int filt_vfswrite(struct knote *kn, long hint);
4327 static int filt_vfsvnode(struct knote *kn, long hint);
4328 static void filt_vfsdetach(struct knote *kn);
4329 static struct filterops vfsread_filtops = {
4330 .f_isfd = 1,
4331 .f_detach = filt_vfsdetach,
4332 .f_event = filt_vfsread
4333 };
4334 static struct filterops vfswrite_filtops = {
4335 .f_isfd = 1,
4336 .f_detach = filt_vfsdetach,
4337 .f_event = filt_vfswrite
4338 };
4339 static struct filterops vfsvnode_filtops = {
4340 .f_isfd = 1,
4341 .f_detach = filt_vfsdetach,
4342 .f_event = filt_vfsvnode
4343 };
4344
4345 static void
4346 vfs_knllock(void *arg)
4347 {
4348 struct vnode *vp = arg;
4349
4350 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4351 }
4352
4353 static void
4354 vfs_knlunlock(void *arg)
4355 {
4356 struct vnode *vp = arg;
4357
4358 VOP_UNLOCK(vp, 0);
4359 }
4360
4361 static void
4362 vfs_knl_assert_locked(void *arg)
4363 {
4364 #ifdef DEBUG_VFS_LOCKS
4365 struct vnode *vp = arg;
4366
4367 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
4368 #endif
4369 }
4370
4371 static void
4372 vfs_knl_assert_unlocked(void *arg)
4373 {
4374 #ifdef DEBUG_VFS_LOCKS
4375 struct vnode *vp = arg;
4376
4377 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
4378 #endif
4379 }
4380
4381 int
4382 vfs_kqfilter(struct vop_kqfilter_args *ap)
4383 {
4384 struct vnode *vp = ap->a_vp;
4385 struct knote *kn = ap->a_kn;
4386 struct knlist *knl;
4387
4388 switch (kn->kn_filter) {
4389 case EVFILT_READ:
4390 kn->kn_fop = &vfsread_filtops;
4391 break;
4392 case EVFILT_WRITE:
4393 kn->kn_fop = &vfswrite_filtops;
4394 break;
4395 case EVFILT_VNODE:
4396 kn->kn_fop = &vfsvnode_filtops;
4397 break;
4398 default:
4399 return (EINVAL);
4400 }
4401
4402 kn->kn_hook = (caddr_t)vp;
4403
4404 v_addpollinfo(vp);
4405 if (vp->v_pollinfo == NULL)
4406 return (ENOMEM);
4407 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
4408 vhold(vp);
4409 knlist_add(knl, kn, 0);
4410
4411 return (0);
4412 }
4413
4414 /*
4415 * Detach knote from vnode
4416 */
4417 static void
4418 filt_vfsdetach(struct knote *kn)
4419 {
4420 struct vnode *vp = (struct vnode *)kn->kn_hook;
4421
4422 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
4423 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
4424 vdrop(vp);
4425 }
4426
4427 /*ARGSUSED*/
4428 static int
4429 filt_vfsread(struct knote *kn, long hint)
4430 {
4431 struct vnode *vp = (struct vnode *)kn->kn_hook;
4432 struct vattr va;
4433 int res;
4434
4435 /*
4436 * filesystem is gone, so set the EOF flag and schedule
4437 * the knote for deletion.
4438 */
4439 if (hint == NOTE_REVOKE) {
4440 VI_LOCK(vp);
4441 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4442 VI_UNLOCK(vp);
4443 return (1);
4444 }
4445
4446 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
4447 return (0);
4448
4449 VI_LOCK(vp);
4450 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
4451 res = (kn->kn_data != 0);
4452 VI_UNLOCK(vp);
4453 return (res);
4454 }
4455
4456 /*ARGSUSED*/
4457 static int
4458 filt_vfswrite(struct knote *kn, long hint)
4459 {
4460 struct vnode *vp = (struct vnode *)kn->kn_hook;
4461
4462 VI_LOCK(vp);
4463
4464 /*
4465 * filesystem is gone, so set the EOF flag and schedule
4466 * the knote for deletion.
4467 */
4468 if (hint == NOTE_REVOKE)
4469 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4470
4471 kn->kn_data = 0;
4472 VI_UNLOCK(vp);
4473 return (1);
4474 }
4475
4476 static int
4477 filt_vfsvnode(struct knote *kn, long hint)
4478 {
4479 struct vnode *vp = (struct vnode *)kn->kn_hook;
4480 int res;
4481
4482 VI_LOCK(vp);
4483 if (kn->kn_sfflags & hint)
4484 kn->kn_fflags |= hint;
4485 if (hint == NOTE_REVOKE) {
4486 kn->kn_flags |= EV_EOF;
4487 VI_UNLOCK(vp);
4488 return (1);
4489 }
4490 res = (kn->kn_fflags != 0);
4491 VI_UNLOCK(vp);
4492 return (res);
4493 }
4494
4495 int
4496 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
4497 {
4498 int error;
4499
4500 if (dp->d_reclen > ap->a_uio->uio_resid)
4501 return (ENAMETOOLONG);
4502 error = uiomove(dp, dp->d_reclen, ap->a_uio);
4503 if (error) {
4504 if (ap->a_ncookies != NULL) {
4505 if (ap->a_cookies != NULL)
4506 free(ap->a_cookies, M_TEMP);
4507 ap->a_cookies = NULL;
4508 *ap->a_ncookies = 0;
4509 }
4510 return (error);
4511 }
4512 if (ap->a_ncookies == NULL)
4513 return (0);
4514
4515 KASSERT(ap->a_cookies,
4516 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
4517
4518 *ap->a_cookies = realloc(*ap->a_cookies,
4519 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
4520 (*ap->a_cookies)[*ap->a_ncookies] = off;
4521 return (0);
4522 }
4523
4524 /*
4525 * Mark for update the access time of the file if the filesystem
4526 * supports VOP_MARKATIME. This functionality is used by execve and
4527 * mmap, so we want to avoid the I/O implied by directly setting
4528 * va_atime for the sake of efficiency.
4529 */
4530 void
4531 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
4532 {
4533 struct mount *mp;
4534
4535 mp = vp->v_mount;
4536 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
4537 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
4538 (void)VOP_MARKATIME(vp);
4539 }
4540
4541 /*
4542 * The purpose of this routine is to remove granularity from accmode_t,
4543 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
4544 * VADMIN and VAPPEND.
4545 *
4546 * If it returns 0, the caller is supposed to continue with the usual
4547 * access checks using 'accmode' as modified by this routine. If it
4548 * returns nonzero value, the caller is supposed to return that value
4549 * as errno.
4550 *
4551 * Note that after this routine runs, accmode may be zero.
4552 */
4553 int
4554 vfs_unixify_accmode(accmode_t *accmode)
4555 {
4556 /*
4557 * There is no way to specify explicit "deny" rule using
4558 * file mode or POSIX.1e ACLs.
4559 */
4560 if (*accmode & VEXPLICIT_DENY) {
4561 *accmode = 0;
4562 return (0);
4563 }
4564
4565 /*
4566 * None of these can be translated into usual access bits.
4567 * Also, the common case for NFSv4 ACLs is to not contain
4568 * either of these bits. Caller should check for VWRITE
4569 * on the containing directory instead.
4570 */
4571 if (*accmode & (VDELETE_CHILD | VDELETE))
4572 return (EPERM);
4573
4574 if (*accmode & VADMIN_PERMS) {
4575 *accmode &= ~VADMIN_PERMS;
4576 *accmode |= VADMIN;
4577 }
4578
4579 /*
4580 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
4581 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
4582 */
4583 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
4584
4585 return (0);
4586 }
4587
4588 /*
4589 * These are helper functions for filesystems to traverse all
4590 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
4591 *
4592 * This interface replaces MNT_VNODE_FOREACH.
4593 */
4594
4595 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
4596
4597 struct vnode *
4598 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
4599 {
4600 struct vnode *vp;
4601
4602 if (should_yield())
4603 kern_yield(PRI_USER);
4604 MNT_ILOCK(mp);
4605 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4606 vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
4607 while (vp != NULL && (vp->v_type == VMARKER ||
4608 (vp->v_iflag & VI_DOOMED) != 0))
4609 vp = TAILQ_NEXT(vp, v_nmntvnodes);
4610
4611 /* Check if we are done */
4612 if (vp == NULL) {
4613 __mnt_vnode_markerfree_all(mvp, mp);
4614 /* MNT_IUNLOCK(mp); -- done in above function */
4615 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
4616 return (NULL);
4617 }
4618 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
4619 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
4620 VI_LOCK(vp);
4621 MNT_IUNLOCK(mp);
4622 return (vp);
4623 }
4624
4625 struct vnode *
4626 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
4627 {
4628 struct vnode *vp;
4629
4630 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
4631 MNT_ILOCK(mp);
4632 MNT_REF(mp);
4633 (*mvp)->v_type = VMARKER;
4634
4635 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
4636 while (vp != NULL && (vp->v_type == VMARKER ||
4637 (vp->v_iflag & VI_DOOMED) != 0))
4638 vp = TAILQ_NEXT(vp, v_nmntvnodes);
4639
4640 /* Check if we are done */
4641 if (vp == NULL) {
4642 MNT_REL(mp);
4643 MNT_IUNLOCK(mp);
4644 free(*mvp, M_VNODE_MARKER);
4645 *mvp = NULL;
4646 return (NULL);
4647 }
4648 (*mvp)->v_mount = mp;
4649 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
4650 VI_LOCK(vp);
4651 MNT_IUNLOCK(mp);
4652 return (vp);
4653 }
4654
4655
4656 void
4657 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
4658 {
4659
4660 if (*mvp == NULL) {
4661 MNT_IUNLOCK(mp);
4662 return;
4663 }
4664
4665 mtx_assert(MNT_MTX(mp), MA_OWNED);
4666
4667 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4668 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
4669 MNT_REL(mp);
4670 MNT_IUNLOCK(mp);
4671 free(*mvp, M_VNODE_MARKER);
4672 *mvp = NULL;
4673 }
4674
4675 /*
4676 * These are helper functions for filesystems to traverse their
4677 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
4678 */
4679 static void
4680 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
4681 {
4682
4683 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4684
4685 MNT_ILOCK(mp);
4686 MNT_REL(mp);
4687 MNT_IUNLOCK(mp);
4688 free(*mvp, M_VNODE_MARKER);
4689 *mvp = NULL;
4690 }
4691
4692 static struct vnode *
4693 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
4694 {
4695 struct vnode *vp, *nvp;
4696
4697 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
4698 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
4699 restart:
4700 vp = TAILQ_NEXT(*mvp, v_actfreelist);
4701 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
4702 while (vp != NULL) {
4703 if (vp->v_type == VMARKER) {
4704 vp = TAILQ_NEXT(vp, v_actfreelist);
4705 continue;
4706 }
4707 if (!VI_TRYLOCK(vp)) {
4708 if (mp_ncpus == 1 || should_yield()) {
4709 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
4710 mtx_unlock(&vnode_free_list_mtx);
4711 pause("vnacti", 1);
4712 mtx_lock(&vnode_free_list_mtx);
4713 goto restart;
4714 }
4715 continue;
4716 }
4717 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
4718 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
4719 ("alien vnode on the active list %p %p", vp, mp));
4720 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0)
4721 break;
4722 nvp = TAILQ_NEXT(vp, v_actfreelist);
4723 VI_UNLOCK(vp);
4724 vp = nvp;
4725 }
4726
4727 /* Check if we are done */
4728 if (vp == NULL) {
4729 mtx_unlock(&vnode_free_list_mtx);
4730 mnt_vnode_markerfree_active(mvp, mp);
4731 return (NULL);
4732 }
4733 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
4734 mtx_unlock(&vnode_free_list_mtx);
4735 ASSERT_VI_LOCKED(vp, "active iter");
4736 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp));
4737 return (vp);
4738 }
4739
4740 struct vnode *
4741 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
4742 {
4743
4744 if (should_yield())
4745 kern_yield(PRI_USER);
4746 mtx_lock(&vnode_free_list_mtx);
4747 return (mnt_vnode_next_active(mvp, mp));
4748 }
4749
4750 struct vnode *
4751 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
4752 {
4753 struct vnode *vp;
4754
4755 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
4756 MNT_ILOCK(mp);
4757 MNT_REF(mp);
4758 MNT_IUNLOCK(mp);
4759 (*mvp)->v_type = VMARKER;
4760 (*mvp)->v_mount = mp;
4761
4762 mtx_lock(&vnode_free_list_mtx);
4763 vp = TAILQ_FIRST(&mp->mnt_activevnodelist);
4764 if (vp == NULL) {
4765 mtx_unlock(&vnode_free_list_mtx);
4766 mnt_vnode_markerfree_active(mvp, mp);
4767 return (NULL);
4768 }
4769 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
4770 return (mnt_vnode_next_active(mvp, mp));
4771 }
4772
4773 void
4774 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
4775 {
4776
4777 if (*mvp == NULL)
4778 return;
4779
4780 mtx_lock(&vnode_free_list_mtx);
4781 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
4782 mtx_unlock(&vnode_free_list_mtx);
4783 mnt_vnode_markerfree_active(mvp, mp);
4784 }
Cache object: 9dd8b1f70f783d78b1f6c46ba2adca26
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