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/8.3/sys/kern/vfs_subr.c 231948 2012-02-21 00:32:24Z kib $");
43
44 #include "opt_ddb.h"
45 #include "opt_watchdog.h"
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/bio.h>
50 #include <sys/buf.h>
51 #include <sys/condvar.h>
52 #include <sys/conf.h>
53 #include <sys/dirent.h>
54 #include <sys/event.h>
55 #include <sys/eventhandler.h>
56 #include <sys/extattr.h>
57 #include <sys/file.h>
58 #include <sys/fcntl.h>
59 #include <sys/jail.h>
60 #include <sys/kdb.h>
61 #include <sys/kernel.h>
62 #include <sys/kthread.h>
63 #include <sys/lockf.h>
64 #include <sys/malloc.h>
65 #include <sys/mount.h>
66 #include <sys/namei.h>
67 #include <sys/priv.h>
68 #include <sys/reboot.h>
69 #include <sys/sched.h>
70 #include <sys/sleepqueue.h>
71 #include <sys/stat.h>
72 #include <sys/sysctl.h>
73 #include <sys/syslog.h>
74 #include <sys/vmmeter.h>
75 #include <sys/vnode.h>
76 #ifdef SW_WATCHDOG
77 #include <sys/watchdog.h>
78 #endif
79
80 #include <machine/stdarg.h>
81
82 #include <security/mac/mac_framework.h>
83
84 #include <vm/vm.h>
85 #include <vm/vm_object.h>
86 #include <vm/vm_extern.h>
87 #include <vm/pmap.h>
88 #include <vm/vm_map.h>
89 #include <vm/vm_page.h>
90 #include <vm/vm_kern.h>
91 #include <vm/uma.h>
92
93 #ifdef DDB
94 #include <ddb/ddb.h>
95 #endif
96
97 #define WI_MPSAFEQ 0
98 #define WI_GIANTQ 1
99
100 static void delmntque(struct vnode *vp);
101 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
102 int slpflag, int slptimeo);
103 static void syncer_shutdown(void *arg, int howto);
104 static int vtryrecycle(struct vnode *vp);
105 static void vbusy(struct vnode *vp);
106 static void vinactive(struct vnode *, struct thread *);
107 static void v_incr_usecount(struct vnode *);
108 static void v_decr_usecount(struct vnode *);
109 static void v_decr_useonly(struct vnode *);
110 static void v_upgrade_usecount(struct vnode *);
111 static void vfree(struct vnode *);
112 static void vnlru_free(int);
113 static void vgonel(struct vnode *);
114 static void vfs_knllock(void *arg);
115 static void vfs_knlunlock(void *arg);
116 static void vfs_knl_assert_locked(void *arg);
117 static void vfs_knl_assert_unlocked(void *arg);
118 static void destroy_vpollinfo(struct vpollinfo *vi);
119
120 /*
121 * Number of vnodes in existence. Increased whenever getnewvnode()
122 * allocates a new vnode, decreased on vdestroy() called on VI_DOOMed
123 * vnode.
124 */
125 static unsigned long numvnodes;
126
127 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
128 "Number of vnodes in existence");
129
130 /*
131 * Conversion tables for conversion from vnode types to inode formats
132 * and back.
133 */
134 enum vtype iftovt_tab[16] = {
135 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
136 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
137 };
138 int vttoif_tab[10] = {
139 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
140 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
141 };
142
143 /*
144 * List of vnodes that are ready for recycling.
145 */
146 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
147
148 /*
149 * Free vnode target. Free vnodes may simply be files which have been stat'd
150 * but not read. This is somewhat common, and a small cache of such files
151 * should be kept to avoid recreation costs.
152 */
153 static u_long wantfreevnodes;
154 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
155 /* Number of vnodes in the free list. */
156 static u_long freevnodes;
157 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0,
158 "Number of vnodes in the free list");
159
160 static int vlru_allow_cache_src;
161 SYSCTL_INT(_vfs, OID_AUTO, vlru_allow_cache_src, CTLFLAG_RW,
162 &vlru_allow_cache_src, 0, "Allow vlru to reclaim source vnode");
163
164 /*
165 * Various variables used for debugging the new implementation of
166 * reassignbuf().
167 * XXX these are probably of (very) limited utility now.
168 */
169 static int reassignbufcalls;
170 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
171 "Number of calls to reassignbuf");
172
173 /*
174 * Cache for the mount type id assigned to NFS. This is used for
175 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
176 */
177 int nfs_mount_type = -1;
178
179 /* To keep more than one thread at a time from running vfs_getnewfsid */
180 static struct mtx mntid_mtx;
181
182 /*
183 * Lock for any access to the following:
184 * vnode_free_list
185 * numvnodes
186 * freevnodes
187 */
188 static struct mtx vnode_free_list_mtx;
189
190 /* Publicly exported FS */
191 struct nfs_public nfs_pub;
192
193 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
194 static uma_zone_t vnode_zone;
195 static uma_zone_t vnodepoll_zone;
196
197 /* Set to 1 to print out reclaim of active vnodes */
198 int prtactive;
199
200 /*
201 * The workitem queue.
202 *
203 * It is useful to delay writes of file data and filesystem metadata
204 * for tens of seconds so that quickly created and deleted files need
205 * not waste disk bandwidth being created and removed. To realize this,
206 * we append vnodes to a "workitem" queue. When running with a soft
207 * updates implementation, most pending metadata dependencies should
208 * not wait for more than a few seconds. Thus, mounted on block devices
209 * are delayed only about a half the time that file data is delayed.
210 * Similarly, directory updates are more critical, so are only delayed
211 * about a third the time that file data is delayed. Thus, there are
212 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
213 * one each second (driven off the filesystem syncer process). The
214 * syncer_delayno variable indicates the next queue that is to be processed.
215 * Items that need to be processed soon are placed in this queue:
216 *
217 * syncer_workitem_pending[syncer_delayno]
218 *
219 * A delay of fifteen seconds is done by placing the request fifteen
220 * entries later in the queue:
221 *
222 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
223 *
224 */
225 static int syncer_delayno;
226 static long syncer_mask;
227 LIST_HEAD(synclist, bufobj);
228 static struct synclist *syncer_workitem_pending[2];
229 /*
230 * The sync_mtx protects:
231 * bo->bo_synclist
232 * sync_vnode_count
233 * syncer_delayno
234 * syncer_state
235 * syncer_workitem_pending
236 * syncer_worklist_len
237 * rushjob
238 */
239 static struct mtx sync_mtx;
240 static struct cv sync_wakeup;
241
242 #define SYNCER_MAXDELAY 32
243 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
244 static int syncdelay = 30; /* max time to delay syncing data */
245 static int filedelay = 30; /* time to delay syncing files */
246 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
247 "Time to delay syncing files (in seconds)");
248 static int dirdelay = 29; /* time to delay syncing directories */
249 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
250 "Time to delay syncing directories (in seconds)");
251 static int metadelay = 28; /* time to delay syncing metadata */
252 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
253 "Time to delay syncing metadata (in seconds)");
254 static int rushjob; /* number of slots to run ASAP */
255 static int stat_rush_requests; /* number of times I/O speeded up */
256 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
257 "Number of times I/O speeded up (rush requests)");
258
259 /*
260 * When shutting down the syncer, run it at four times normal speed.
261 */
262 #define SYNCER_SHUTDOWN_SPEEDUP 4
263 static int sync_vnode_count;
264 static int syncer_worklist_len;
265 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
266 syncer_state;
267
268 /*
269 * Number of vnodes we want to exist at any one time. This is mostly used
270 * to size hash tables in vnode-related code. It is normally not used in
271 * getnewvnode(), as wantfreevnodes is normally nonzero.)
272 *
273 * XXX desiredvnodes is historical cruft and should not exist.
274 */
275 int desiredvnodes;
276 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
277 &desiredvnodes, 0, "Maximum number of vnodes");
278 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
279 &wantfreevnodes, 0, "Minimum number of vnodes (legacy)");
280 static int vnlru_nowhere;
281 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
282 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
283
284 /*
285 * Macros to control when a vnode is freed and recycled. All require
286 * the vnode interlock.
287 */
288 #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
289 #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt)
290 #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt)
291
292
293 /*
294 * Initialize the vnode management data structures.
295 *
296 * Reevaluate the following cap on the number of vnodes after the physical
297 * memory size exceeds 512GB. In the limit, as the physical memory size
298 * grows, the ratio of physical pages to vnodes approaches sixteen to one.
299 */
300 #ifndef MAXVNODES_MAX
301 #define MAXVNODES_MAX (512 * (1024 * 1024 * 1024 / (int)PAGE_SIZE / 16))
302 #endif
303 static void
304 vntblinit(void *dummy __unused)
305 {
306 int physvnodes, virtvnodes;
307
308 /*
309 * Desiredvnodes is a function of the physical memory size and the
310 * kernel's heap size. Generally speaking, it scales with the
311 * physical memory size. The ratio of desiredvnodes to physical pages
312 * is one to four until desiredvnodes exceeds 98,304. Thereafter, the
313 * marginal ratio of desiredvnodes to physical pages is one to
314 * sixteen. However, desiredvnodes is limited by the kernel's heap
315 * size. The memory required by desiredvnodes vnodes and vm objects
316 * may not exceed one seventh of the kernel's heap size.
317 */
318 physvnodes = maxproc + cnt.v_page_count / 16 + 3 * min(98304 * 4,
319 cnt.v_page_count) / 16;
320 virtvnodes = vm_kmem_size / (7 * (sizeof(struct vm_object) +
321 sizeof(struct vnode)));
322 desiredvnodes = min(physvnodes, virtvnodes);
323 if (desiredvnodes > MAXVNODES_MAX) {
324 if (bootverbose)
325 printf("Reducing kern.maxvnodes %d -> %d\n",
326 desiredvnodes, MAXVNODES_MAX);
327 desiredvnodes = MAXVNODES_MAX;
328 }
329 wantfreevnodes = desiredvnodes / 4;
330 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
331 TAILQ_INIT(&vnode_free_list);
332 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
333 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
334 NULL, NULL, UMA_ALIGN_PTR, 0);
335 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
336 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
337 /*
338 * Initialize the filesystem syncer.
339 */
340 syncer_workitem_pending[WI_MPSAFEQ] = hashinit(syncer_maxdelay, M_VNODE,
341 &syncer_mask);
342 syncer_workitem_pending[WI_GIANTQ] = hashinit(syncer_maxdelay, M_VNODE,
343 &syncer_mask);
344 syncer_maxdelay = syncer_mask + 1;
345 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
346 cv_init(&sync_wakeup, "syncer");
347 }
348 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
349
350
351 /*
352 * Mark a mount point as busy. Used to synchronize access and to delay
353 * unmounting. Eventually, mountlist_mtx is not released on failure.
354 *
355 * vfs_busy() is a custom lock, it can block the caller.
356 * vfs_busy() only sleeps if the unmount is active on the mount point.
357 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
358 * vnode belonging to mp.
359 *
360 * Lookup uses vfs_busy() to traverse mount points.
361 * root fs var fs
362 * / vnode lock A / vnode lock (/var) D
363 * /var vnode lock B /log vnode lock(/var/log) E
364 * vfs_busy lock C vfs_busy lock F
365 *
366 * Within each file system, the lock order is C->A->B and F->D->E.
367 *
368 * When traversing across mounts, the system follows that lock order:
369 *
370 * C->A->B
371 * |
372 * +->F->D->E
373 *
374 * The lookup() process for namei("/var") illustrates the process:
375 * VOP_LOOKUP() obtains B while A is held
376 * vfs_busy() obtains a shared lock on F while A and B are held
377 * vput() releases lock on B
378 * vput() releases lock on A
379 * VFS_ROOT() obtains lock on D while shared lock on F is held
380 * vfs_unbusy() releases shared lock on F
381 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
382 * Attempt to lock A (instead of vp_crossmp) while D is held would
383 * violate the global order, causing deadlocks.
384 *
385 * dounmount() locks B while F is drained.
386 */
387 int
388 vfs_busy(struct mount *mp, int flags)
389 {
390
391 MPASS((flags & ~MBF_MASK) == 0);
392 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
393
394 MNT_ILOCK(mp);
395 MNT_REF(mp);
396 /*
397 * If mount point is currenly being unmounted, sleep until the
398 * mount point fate is decided. If thread doing the unmounting fails,
399 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
400 * that this mount point has survived the unmount attempt and vfs_busy
401 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
402 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
403 * about to be really destroyed. vfs_busy needs to release its
404 * reference on the mount point in this case and return with ENOENT,
405 * telling the caller that mount mount it tried to busy is no longer
406 * valid.
407 */
408 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
409 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
410 MNT_REL(mp);
411 MNT_IUNLOCK(mp);
412 CTR1(KTR_VFS, "%s: failed busying before sleeping",
413 __func__);
414 return (ENOENT);
415 }
416 if (flags & MBF_MNTLSTLOCK)
417 mtx_unlock(&mountlist_mtx);
418 mp->mnt_kern_flag |= MNTK_MWAIT;
419 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
420 if (flags & MBF_MNTLSTLOCK)
421 mtx_lock(&mountlist_mtx);
422 MNT_ILOCK(mp);
423 }
424 if (flags & MBF_MNTLSTLOCK)
425 mtx_unlock(&mountlist_mtx);
426 mp->mnt_lockref++;
427 MNT_IUNLOCK(mp);
428 return (0);
429 }
430
431 /*
432 * Free a busy filesystem.
433 */
434 void
435 vfs_unbusy(struct mount *mp)
436 {
437
438 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
439 MNT_ILOCK(mp);
440 MNT_REL(mp);
441 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
442 mp->mnt_lockref--;
443 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
444 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
445 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
446 mp->mnt_kern_flag &= ~MNTK_DRAINING;
447 wakeup(&mp->mnt_lockref);
448 }
449 MNT_IUNLOCK(mp);
450 }
451
452 /*
453 * Lookup a mount point by filesystem identifier.
454 */
455 struct mount *
456 vfs_getvfs(fsid_t *fsid)
457 {
458 struct mount *mp;
459
460 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
461 mtx_lock(&mountlist_mtx);
462 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
463 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
464 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
465 vfs_ref(mp);
466 mtx_unlock(&mountlist_mtx);
467 return (mp);
468 }
469 }
470 mtx_unlock(&mountlist_mtx);
471 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
472 return ((struct mount *) 0);
473 }
474
475 /*
476 * Lookup a mount point by filesystem identifier, busying it before
477 * returning.
478 */
479 struct mount *
480 vfs_busyfs(fsid_t *fsid)
481 {
482 struct mount *mp;
483 int error;
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 error = vfs_busy(mp, MBF_MNTLSTLOCK);
491 if (error) {
492 mtx_unlock(&mountlist_mtx);
493 return (NULL);
494 }
495 return (mp);
496 }
497 }
498 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
499 mtx_unlock(&mountlist_mtx);
500 return ((struct mount *) 0);
501 }
502
503 /*
504 * Check if a user can access privileged mount options.
505 */
506 int
507 vfs_suser(struct mount *mp, struct thread *td)
508 {
509 int error;
510
511 /*
512 * If the thread is jailed, but this is not a jail-friendly file
513 * system, deny immediately.
514 */
515 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
516 return (EPERM);
517
518 /*
519 * If the file system was mounted outside the jail of the calling
520 * thread, deny immediately.
521 */
522 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
523 return (EPERM);
524
525 /*
526 * If file system supports delegated administration, we don't check
527 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
528 * by the file system itself.
529 * If this is not the user that did original mount, we check for
530 * the PRIV_VFS_MOUNT_OWNER privilege.
531 */
532 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
533 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
534 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
535 return (error);
536 }
537 return (0);
538 }
539
540 /*
541 * Get a new unique fsid. Try to make its val[0] unique, since this value
542 * will be used to create fake device numbers for stat(). Also try (but
543 * not so hard) make its val[0] unique mod 2^16, since some emulators only
544 * support 16-bit device numbers. We end up with unique val[0]'s for the
545 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
546 *
547 * Keep in mind that several mounts may be running in parallel. Starting
548 * the search one past where the previous search terminated is both a
549 * micro-optimization and a defense against returning the same fsid to
550 * different mounts.
551 */
552 void
553 vfs_getnewfsid(struct mount *mp)
554 {
555 static u_int16_t mntid_base;
556 struct mount *nmp;
557 fsid_t tfsid;
558 int mtype;
559
560 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
561 mtx_lock(&mntid_mtx);
562 mtype = mp->mnt_vfc->vfc_typenum;
563 tfsid.val[1] = mtype;
564 mtype = (mtype & 0xFF) << 24;
565 for (;;) {
566 tfsid.val[0] = makedev(255,
567 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
568 mntid_base++;
569 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
570 break;
571 vfs_rel(nmp);
572 }
573 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
574 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
575 mtx_unlock(&mntid_mtx);
576 }
577
578 /*
579 * Knob to control the precision of file timestamps:
580 *
581 * 0 = seconds only; nanoseconds zeroed.
582 * 1 = seconds and nanoseconds, accurate within 1/HZ.
583 * 2 = seconds and nanoseconds, truncated to microseconds.
584 * >=3 = seconds and nanoseconds, maximum precision.
585 */
586 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
587
588 static int timestamp_precision = TSP_SEC;
589 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
590 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
591 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, "
592 "3+: sec + ns (max. precision))");
593
594 /*
595 * Get a current timestamp.
596 */
597 void
598 vfs_timestamp(struct timespec *tsp)
599 {
600 struct timeval tv;
601
602 switch (timestamp_precision) {
603 case TSP_SEC:
604 tsp->tv_sec = time_second;
605 tsp->tv_nsec = 0;
606 break;
607 case TSP_HZ:
608 getnanotime(tsp);
609 break;
610 case TSP_USEC:
611 microtime(&tv);
612 TIMEVAL_TO_TIMESPEC(&tv, tsp);
613 break;
614 case TSP_NSEC:
615 default:
616 nanotime(tsp);
617 break;
618 }
619 }
620
621 /*
622 * Set vnode attributes to VNOVAL
623 */
624 void
625 vattr_null(struct vattr *vap)
626 {
627
628 vap->va_type = VNON;
629 vap->va_size = VNOVAL;
630 vap->va_bytes = VNOVAL;
631 vap->va_mode = VNOVAL;
632 vap->va_nlink = VNOVAL;
633 vap->va_uid = VNOVAL;
634 vap->va_gid = VNOVAL;
635 vap->va_fsid = VNOVAL;
636 vap->va_fileid = VNOVAL;
637 vap->va_blocksize = VNOVAL;
638 vap->va_rdev = VNOVAL;
639 vap->va_atime.tv_sec = VNOVAL;
640 vap->va_atime.tv_nsec = VNOVAL;
641 vap->va_mtime.tv_sec = VNOVAL;
642 vap->va_mtime.tv_nsec = VNOVAL;
643 vap->va_ctime.tv_sec = VNOVAL;
644 vap->va_ctime.tv_nsec = VNOVAL;
645 vap->va_birthtime.tv_sec = VNOVAL;
646 vap->va_birthtime.tv_nsec = VNOVAL;
647 vap->va_flags = VNOVAL;
648 vap->va_gen = VNOVAL;
649 vap->va_vaflags = 0;
650 }
651
652 /*
653 * This routine is called when we have too many vnodes. It attempts
654 * to free <count> vnodes and will potentially free vnodes that still
655 * have VM backing store (VM backing store is typically the cause
656 * of a vnode blowout so we want to do this). Therefore, this operation
657 * is not considered cheap.
658 *
659 * A number of conditions may prevent a vnode from being reclaimed.
660 * the buffer cache may have references on the vnode, a directory
661 * vnode may still have references due to the namei cache representing
662 * underlying files, or the vnode may be in active use. It is not
663 * desireable to reuse such vnodes. These conditions may cause the
664 * number of vnodes to reach some minimum value regardless of what
665 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
666 */
667 static int
668 vlrureclaim(struct mount *mp)
669 {
670 struct vnode *vp;
671 int done;
672 int trigger;
673 int usevnodes;
674 int count;
675
676 /*
677 * Calculate the trigger point, don't allow user
678 * screwups to blow us up. This prevents us from
679 * recycling vnodes with lots of resident pages. We
680 * aren't trying to free memory, we are trying to
681 * free vnodes.
682 */
683 usevnodes = desiredvnodes;
684 if (usevnodes <= 0)
685 usevnodes = 1;
686 trigger = cnt.v_page_count * 2 / usevnodes;
687 done = 0;
688 vn_start_write(NULL, &mp, V_WAIT);
689 MNT_ILOCK(mp);
690 count = mp->mnt_nvnodelistsize / 10 + 1;
691 while (count != 0) {
692 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
693 while (vp != NULL && vp->v_type == VMARKER)
694 vp = TAILQ_NEXT(vp, v_nmntvnodes);
695 if (vp == NULL)
696 break;
697 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
698 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
699 --count;
700 if (!VI_TRYLOCK(vp))
701 goto next_iter;
702 /*
703 * If it's been deconstructed already, it's still
704 * referenced, or it exceeds the trigger, skip it.
705 */
706 if (vp->v_usecount ||
707 (!vlru_allow_cache_src &&
708 !LIST_EMPTY(&(vp)->v_cache_src)) ||
709 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
710 vp->v_object->resident_page_count > trigger)) {
711 VI_UNLOCK(vp);
712 goto next_iter;
713 }
714 MNT_IUNLOCK(mp);
715 vholdl(vp);
716 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
717 vdrop(vp);
718 goto next_iter_mntunlocked;
719 }
720 VI_LOCK(vp);
721 /*
722 * v_usecount may have been bumped after VOP_LOCK() dropped
723 * the vnode interlock and before it was locked again.
724 *
725 * It is not necessary to recheck VI_DOOMED because it can
726 * only be set by another thread that holds both the vnode
727 * lock and vnode interlock. If another thread has the
728 * vnode lock before we get to VOP_LOCK() and obtains the
729 * vnode interlock after VOP_LOCK() drops the vnode
730 * interlock, the other thread will be unable to drop the
731 * vnode lock before our VOP_LOCK() call fails.
732 */
733 if (vp->v_usecount ||
734 (!vlru_allow_cache_src &&
735 !LIST_EMPTY(&(vp)->v_cache_src)) ||
736 (vp->v_object != NULL &&
737 vp->v_object->resident_page_count > trigger)) {
738 VOP_UNLOCK(vp, LK_INTERLOCK);
739 goto next_iter_mntunlocked;
740 }
741 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
742 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
743 vgonel(vp);
744 VOP_UNLOCK(vp, 0);
745 vdropl(vp);
746 done++;
747 next_iter_mntunlocked:
748 if ((count % 256) != 0)
749 goto relock_mnt;
750 goto yield;
751 next_iter:
752 if ((count % 256) != 0)
753 continue;
754 MNT_IUNLOCK(mp);
755 yield:
756 uio_yield();
757 relock_mnt:
758 MNT_ILOCK(mp);
759 }
760 MNT_IUNLOCK(mp);
761 vn_finished_write(mp);
762 return done;
763 }
764
765 /*
766 * Attempt to keep the free list at wantfreevnodes length.
767 */
768 static void
769 vnlru_free(int count)
770 {
771 struct vnode *vp;
772 int vfslocked;
773
774 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
775 for (; count > 0; count--) {
776 vp = TAILQ_FIRST(&vnode_free_list);
777 /*
778 * The list can be modified while the free_list_mtx
779 * has been dropped and vp could be NULL here.
780 */
781 if (!vp)
782 break;
783 VNASSERT(vp->v_op != NULL, vp,
784 ("vnlru_free: vnode already reclaimed."));
785 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
786 /*
787 * Don't recycle if we can't get the interlock.
788 */
789 if (!VI_TRYLOCK(vp)) {
790 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
791 continue;
792 }
793 VNASSERT(VCANRECYCLE(vp), vp,
794 ("vp inconsistent on freelist"));
795 freevnodes--;
796 vp->v_iflag &= ~VI_FREE;
797 vholdl(vp);
798 mtx_unlock(&vnode_free_list_mtx);
799 VI_UNLOCK(vp);
800 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
801 vtryrecycle(vp);
802 VFS_UNLOCK_GIANT(vfslocked);
803 /*
804 * If the recycled succeeded this vdrop will actually free
805 * the vnode. If not it will simply place it back on
806 * the free list.
807 */
808 vdrop(vp);
809 mtx_lock(&vnode_free_list_mtx);
810 }
811 }
812 /*
813 * Attempt to recycle vnodes in a context that is always safe to block.
814 * Calling vlrurecycle() from the bowels of filesystem code has some
815 * interesting deadlock problems.
816 */
817 static struct proc *vnlruproc;
818 static int vnlruproc_sig;
819
820 static void
821 vnlru_proc(void)
822 {
823 struct mount *mp, *nmp;
824 int done, vfslocked;
825 struct proc *p = vnlruproc;
826
827 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p,
828 SHUTDOWN_PRI_FIRST);
829
830 for (;;) {
831 kproc_suspend_check(p);
832 mtx_lock(&vnode_free_list_mtx);
833 if (freevnodes > wantfreevnodes)
834 vnlru_free(freevnodes - wantfreevnodes);
835 if (numvnodes <= desiredvnodes * 9 / 10) {
836 vnlruproc_sig = 0;
837 wakeup(&vnlruproc_sig);
838 msleep(vnlruproc, &vnode_free_list_mtx,
839 PVFS|PDROP, "vlruwt", hz);
840 continue;
841 }
842 mtx_unlock(&vnode_free_list_mtx);
843 done = 0;
844 mtx_lock(&mountlist_mtx);
845 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
846 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
847 nmp = TAILQ_NEXT(mp, mnt_list);
848 continue;
849 }
850 vfslocked = VFS_LOCK_GIANT(mp);
851 done += vlrureclaim(mp);
852 VFS_UNLOCK_GIANT(vfslocked);
853 mtx_lock(&mountlist_mtx);
854 nmp = TAILQ_NEXT(mp, mnt_list);
855 vfs_unbusy(mp);
856 }
857 mtx_unlock(&mountlist_mtx);
858 if (done == 0) {
859 #if 0
860 /* These messages are temporary debugging aids */
861 if (vnlru_nowhere < 5)
862 printf("vnlru process getting nowhere..\n");
863 else if (vnlru_nowhere == 5)
864 printf("vnlru process messages stopped.\n");
865 #endif
866 vnlru_nowhere++;
867 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
868 } else
869 uio_yield();
870 }
871 }
872
873 static struct kproc_desc vnlru_kp = {
874 "vnlru",
875 vnlru_proc,
876 &vnlruproc
877 };
878 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
879 &vnlru_kp);
880
881 /*
882 * Routines having to do with the management of the vnode table.
883 */
884
885 void
886 vdestroy(struct vnode *vp)
887 {
888 struct bufobj *bo;
889
890 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
891 mtx_lock(&vnode_free_list_mtx);
892 numvnodes--;
893 mtx_unlock(&vnode_free_list_mtx);
894 bo = &vp->v_bufobj;
895 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
896 ("cleaned vnode still on the free list."));
897 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
898 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
899 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
900 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
901 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
902 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
903 VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL"));
904 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
905 VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL"));
906 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
907 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
908 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
909 VI_UNLOCK(vp);
910 #ifdef MAC
911 mac_vnode_destroy(vp);
912 #endif
913 if (vp->v_pollinfo != NULL)
914 destroy_vpollinfo(vp->v_pollinfo);
915 #ifdef INVARIANTS
916 /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */
917 vp->v_op = NULL;
918 #endif
919 lockdestroy(vp->v_vnlock);
920 mtx_destroy(&vp->v_interlock);
921 mtx_destroy(BO_MTX(bo));
922 uma_zfree(vnode_zone, vp);
923 }
924
925 /*
926 * Try to recycle a freed vnode. We abort if anyone picks up a reference
927 * before we actually vgone(). This function must be called with the vnode
928 * held to prevent the vnode from being returned to the free list midway
929 * through vgone().
930 */
931 static int
932 vtryrecycle(struct vnode *vp)
933 {
934 struct mount *vnmp;
935
936 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
937 VNASSERT(vp->v_holdcnt, vp,
938 ("vtryrecycle: Recycling vp %p without a reference.", vp));
939 /*
940 * This vnode may found and locked via some other list, if so we
941 * can't recycle it yet.
942 */
943 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
944 CTR2(KTR_VFS,
945 "%s: impossible to recycle, vp %p lock is already held",
946 __func__, vp);
947 return (EWOULDBLOCK);
948 }
949 /*
950 * Don't recycle if its filesystem is being suspended.
951 */
952 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
953 VOP_UNLOCK(vp, 0);
954 CTR2(KTR_VFS,
955 "%s: impossible to recycle, cannot start the write for %p",
956 __func__, vp);
957 return (EBUSY);
958 }
959 /*
960 * If we got this far, we need to acquire the interlock and see if
961 * anyone picked up this vnode from another list. If not, we will
962 * mark it with DOOMED via vgonel() so that anyone who does find it
963 * will skip over it.
964 */
965 VI_LOCK(vp);
966 if (vp->v_usecount) {
967 VOP_UNLOCK(vp, LK_INTERLOCK);
968 vn_finished_write(vnmp);
969 CTR2(KTR_VFS,
970 "%s: impossible to recycle, %p is already referenced",
971 __func__, vp);
972 return (EBUSY);
973 }
974 if ((vp->v_iflag & VI_DOOMED) == 0)
975 vgonel(vp);
976 VOP_UNLOCK(vp, LK_INTERLOCK);
977 vn_finished_write(vnmp);
978 return (0);
979 }
980
981 /*
982 * Return the next vnode from the free list.
983 */
984 int
985 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
986 struct vnode **vpp)
987 {
988 struct vnode *vp = NULL;
989 struct bufobj *bo;
990
991 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
992 mtx_lock(&vnode_free_list_mtx);
993 /*
994 * Lend our context to reclaim vnodes if they've exceeded the max.
995 */
996 if (freevnodes > wantfreevnodes)
997 vnlru_free(1);
998 /*
999 * Wait for available vnodes.
1000 */
1001 if (numvnodes > desiredvnodes) {
1002 if (mp != NULL && (mp->mnt_kern_flag & MNTK_SUSPEND)) {
1003 /*
1004 * File system is beeing suspended, we cannot risk a
1005 * deadlock here, so allocate new vnode anyway.
1006 */
1007 if (freevnodes > wantfreevnodes)
1008 vnlru_free(freevnodes - wantfreevnodes);
1009 goto alloc;
1010 }
1011 if (vnlruproc_sig == 0) {
1012 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
1013 wakeup(vnlruproc);
1014 }
1015 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
1016 "vlruwk", hz);
1017 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
1018 if (numvnodes > desiredvnodes) {
1019 mtx_unlock(&vnode_free_list_mtx);
1020 return (ENFILE);
1021 }
1022 #endif
1023 }
1024 alloc:
1025 numvnodes++;
1026 mtx_unlock(&vnode_free_list_mtx);
1027 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO);
1028 /*
1029 * Setup locks.
1030 */
1031 vp->v_vnlock = &vp->v_lock;
1032 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
1033 /*
1034 * By default, don't allow shared locks unless filesystems
1035 * opt-in.
1036 */
1037 lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE);
1038 /*
1039 * Initialize bufobj.
1040 */
1041 bo = &vp->v_bufobj;
1042 bo->__bo_vnode = vp;
1043 mtx_init(BO_MTX(bo), "bufobj interlock", NULL, MTX_DEF);
1044 bo->bo_ops = &buf_ops_bio;
1045 bo->bo_private = vp;
1046 TAILQ_INIT(&bo->bo_clean.bv_hd);
1047 TAILQ_INIT(&bo->bo_dirty.bv_hd);
1048 /*
1049 * Initialize namecache.
1050 */
1051 LIST_INIT(&vp->v_cache_src);
1052 TAILQ_INIT(&vp->v_cache_dst);
1053 /*
1054 * Finalize various vnode identity bits.
1055 */
1056 vp->v_type = VNON;
1057 vp->v_tag = tag;
1058 vp->v_op = vops;
1059 v_incr_usecount(vp);
1060 vp->v_data = 0;
1061 #ifdef MAC
1062 mac_vnode_init(vp);
1063 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1064 mac_vnode_associate_singlelabel(mp, vp);
1065 else if (mp == NULL && vops != &dead_vnodeops)
1066 printf("NULL mp in getnewvnode()\n");
1067 #endif
1068 if (mp != NULL) {
1069 bo->bo_bsize = mp->mnt_stat.f_iosize;
1070 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1071 vp->v_vflag |= VV_NOKNOTE;
1072 }
1073
1074 *vpp = vp;
1075 return (0);
1076 }
1077
1078 /*
1079 * Delete from old mount point vnode list, if on one.
1080 */
1081 static void
1082 delmntque(struct vnode *vp)
1083 {
1084 struct mount *mp;
1085
1086 mp = vp->v_mount;
1087 if (mp == NULL)
1088 return;
1089 MNT_ILOCK(mp);
1090 vp->v_mount = NULL;
1091 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1092 ("bad mount point vnode list size"));
1093 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1094 mp->mnt_nvnodelistsize--;
1095 MNT_REL(mp);
1096 MNT_IUNLOCK(mp);
1097 }
1098
1099 static void
1100 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1101 {
1102
1103 vp->v_data = NULL;
1104 vp->v_op = &dead_vnodeops;
1105 /* XXX non mp-safe fs may still call insmntque with vnode
1106 unlocked */
1107 if (!VOP_ISLOCKED(vp))
1108 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1109 vgone(vp);
1110 vput(vp);
1111 }
1112
1113 /*
1114 * Insert into list of vnodes for the new mount point, if available.
1115 */
1116 int
1117 insmntque1(struct vnode *vp, struct mount *mp,
1118 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1119 {
1120 int locked;
1121
1122 KASSERT(vp->v_mount == NULL,
1123 ("insmntque: vnode already on per mount vnode list"));
1124 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1125 #ifdef DEBUG_VFS_LOCKS
1126 if (!VFS_NEEDSGIANT(mp))
1127 ASSERT_VOP_ELOCKED(vp,
1128 "insmntque: mp-safe fs and non-locked vp");
1129 #endif
1130 MNT_ILOCK(mp);
1131 if ((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1132 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1133 mp->mnt_nvnodelistsize == 0)) {
1134 locked = VOP_ISLOCKED(vp);
1135 if (!locked || (locked == LK_EXCLUSIVE &&
1136 (vp->v_vflag & VV_FORCEINSMQ) == 0)) {
1137 MNT_IUNLOCK(mp);
1138 if (dtr != NULL)
1139 dtr(vp, dtr_arg);
1140 return (EBUSY);
1141 }
1142 }
1143 vp->v_mount = mp;
1144 MNT_REF(mp);
1145 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1146 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1147 ("neg mount point vnode list size"));
1148 mp->mnt_nvnodelistsize++;
1149 MNT_IUNLOCK(mp);
1150 return (0);
1151 }
1152
1153 int
1154 insmntque(struct vnode *vp, struct mount *mp)
1155 {
1156
1157 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1158 }
1159
1160 /*
1161 * Flush out and invalidate all buffers associated with a bufobj
1162 * Called with the underlying object locked.
1163 */
1164 int
1165 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1166 {
1167 int error;
1168
1169 BO_LOCK(bo);
1170 if (flags & V_SAVE) {
1171 error = bufobj_wwait(bo, slpflag, slptimeo);
1172 if (error) {
1173 BO_UNLOCK(bo);
1174 return (error);
1175 }
1176 if (bo->bo_dirty.bv_cnt > 0) {
1177 BO_UNLOCK(bo);
1178 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1179 return (error);
1180 /*
1181 * XXX We could save a lock/unlock if this was only
1182 * enabled under INVARIANTS
1183 */
1184 BO_LOCK(bo);
1185 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1186 panic("vinvalbuf: dirty bufs");
1187 }
1188 }
1189 /*
1190 * If you alter this loop please notice that interlock is dropped and
1191 * reacquired in flushbuflist. Special care is needed to ensure that
1192 * no race conditions occur from this.
1193 */
1194 do {
1195 error = flushbuflist(&bo->bo_clean,
1196 flags, bo, slpflag, slptimeo);
1197 if (error == 0 && !(flags & V_CLEANONLY))
1198 error = flushbuflist(&bo->bo_dirty,
1199 flags, bo, slpflag, slptimeo);
1200 if (error != 0 && error != EAGAIN) {
1201 BO_UNLOCK(bo);
1202 return (error);
1203 }
1204 } while (error != 0);
1205
1206 /*
1207 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1208 * have write I/O in-progress but if there is a VM object then the
1209 * VM object can also have read-I/O in-progress.
1210 */
1211 do {
1212 bufobj_wwait(bo, 0, 0);
1213 BO_UNLOCK(bo);
1214 if (bo->bo_object != NULL) {
1215 VM_OBJECT_LOCK(bo->bo_object);
1216 vm_object_pip_wait(bo->bo_object, "bovlbx");
1217 VM_OBJECT_UNLOCK(bo->bo_object);
1218 }
1219 BO_LOCK(bo);
1220 } while (bo->bo_numoutput > 0);
1221 BO_UNLOCK(bo);
1222
1223 /*
1224 * Destroy the copy in the VM cache, too.
1225 */
1226 if (bo->bo_object != NULL &&
1227 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
1228 VM_OBJECT_LOCK(bo->bo_object);
1229 vm_object_page_remove(bo->bo_object, 0, 0,
1230 (flags & V_SAVE) ? TRUE : FALSE);
1231 VM_OBJECT_UNLOCK(bo->bo_object);
1232 }
1233
1234 #ifdef INVARIANTS
1235 BO_LOCK(bo);
1236 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
1237 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1238 panic("vinvalbuf: flush failed");
1239 BO_UNLOCK(bo);
1240 #endif
1241 return (0);
1242 }
1243
1244 /*
1245 * Flush out and invalidate all buffers associated with a vnode.
1246 * Called with the underlying object locked.
1247 */
1248 int
1249 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1250 {
1251
1252 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1253 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1254 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1255 }
1256
1257 /*
1258 * Flush out buffers on the specified list.
1259 *
1260 */
1261 static int
1262 flushbuflist( struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1263 int slptimeo)
1264 {
1265 struct buf *bp, *nbp;
1266 int retval, error;
1267 daddr_t lblkno;
1268 b_xflags_t xflags;
1269
1270 ASSERT_BO_LOCKED(bo);
1271
1272 retval = 0;
1273 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1274 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1275 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1276 continue;
1277 }
1278 lblkno = 0;
1279 xflags = 0;
1280 if (nbp != NULL) {
1281 lblkno = nbp->b_lblkno;
1282 xflags = nbp->b_xflags &
1283 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
1284 }
1285 retval = EAGAIN;
1286 error = BUF_TIMELOCK(bp,
1287 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo),
1288 "flushbuf", slpflag, slptimeo);
1289 if (error) {
1290 BO_LOCK(bo);
1291 return (error != ENOLCK ? error : EAGAIN);
1292 }
1293 KASSERT(bp->b_bufobj == bo,
1294 ("bp %p wrong b_bufobj %p should be %p",
1295 bp, bp->b_bufobj, bo));
1296 if (bp->b_bufobj != bo) { /* XXX: necessary ? */
1297 BUF_UNLOCK(bp);
1298 BO_LOCK(bo);
1299 return (EAGAIN);
1300 }
1301 /*
1302 * XXX Since there are no node locks for NFS, I
1303 * believe there is a slight chance that a delayed
1304 * write will occur while sleeping just above, so
1305 * check for it.
1306 */
1307 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1308 (flags & V_SAVE)) {
1309 BO_LOCK(bo);
1310 bremfree(bp);
1311 BO_UNLOCK(bo);
1312 bp->b_flags |= B_ASYNC;
1313 bwrite(bp);
1314 BO_LOCK(bo);
1315 return (EAGAIN); /* XXX: why not loop ? */
1316 }
1317 BO_LOCK(bo);
1318 bremfree(bp);
1319 BO_UNLOCK(bo);
1320 bp->b_flags |= (B_INVAL | B_RELBUF);
1321 bp->b_flags &= ~B_ASYNC;
1322 brelse(bp);
1323 BO_LOCK(bo);
1324 if (nbp != NULL &&
1325 (nbp->b_bufobj != bo ||
1326 nbp->b_lblkno != lblkno ||
1327 (nbp->b_xflags &
1328 (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
1329 break; /* nbp invalid */
1330 }
1331 return (retval);
1332 }
1333
1334 /*
1335 * Truncate a file's buffer and pages to a specified length. This
1336 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1337 * sync activity.
1338 */
1339 int
1340 vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
1341 off_t length, int blksize)
1342 {
1343 struct buf *bp, *nbp;
1344 int anyfreed;
1345 int trunclbn;
1346 struct bufobj *bo;
1347
1348 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__,
1349 vp, cred, blksize, (uintmax_t)length);
1350
1351 /*
1352 * Round up to the *next* lbn.
1353 */
1354 trunclbn = (length + blksize - 1) / blksize;
1355
1356 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1357 restart:
1358 bo = &vp->v_bufobj;
1359 BO_LOCK(bo);
1360 anyfreed = 1;
1361 for (;anyfreed;) {
1362 anyfreed = 0;
1363 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1364 if (bp->b_lblkno < trunclbn)
1365 continue;
1366 if (BUF_LOCK(bp,
1367 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1368 BO_MTX(bo)) == ENOLCK)
1369 goto restart;
1370
1371 BO_LOCK(bo);
1372 bremfree(bp);
1373 BO_UNLOCK(bo);
1374 bp->b_flags |= (B_INVAL | B_RELBUF);
1375 bp->b_flags &= ~B_ASYNC;
1376 brelse(bp);
1377 anyfreed = 1;
1378
1379 BO_LOCK(bo);
1380 if (nbp != NULL &&
1381 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1382 (nbp->b_vp != vp) ||
1383 (nbp->b_flags & B_DELWRI))) {
1384 BO_UNLOCK(bo);
1385 goto restart;
1386 }
1387 }
1388
1389 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1390 if (bp->b_lblkno < trunclbn)
1391 continue;
1392 if (BUF_LOCK(bp,
1393 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1394 BO_MTX(bo)) == ENOLCK)
1395 goto restart;
1396 BO_LOCK(bo);
1397 bremfree(bp);
1398 BO_UNLOCK(bo);
1399 bp->b_flags |= (B_INVAL | B_RELBUF);
1400 bp->b_flags &= ~B_ASYNC;
1401 brelse(bp);
1402 anyfreed = 1;
1403
1404 BO_LOCK(bo);
1405 if (nbp != NULL &&
1406 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1407 (nbp->b_vp != vp) ||
1408 (nbp->b_flags & B_DELWRI) == 0)) {
1409 BO_UNLOCK(bo);
1410 goto restart;
1411 }
1412 }
1413 }
1414
1415 if (length > 0) {
1416 restartsync:
1417 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1418 if (bp->b_lblkno > 0)
1419 continue;
1420 /*
1421 * Since we hold the vnode lock this should only
1422 * fail if we're racing with the buf daemon.
1423 */
1424 if (BUF_LOCK(bp,
1425 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1426 BO_MTX(bo)) == ENOLCK) {
1427 goto restart;
1428 }
1429 VNASSERT((bp->b_flags & B_DELWRI), vp,
1430 ("buf(%p) on dirty queue without DELWRI", bp));
1431
1432 BO_LOCK(bo);
1433 bremfree(bp);
1434 BO_UNLOCK(bo);
1435 bawrite(bp);
1436 BO_LOCK(bo);
1437 goto restartsync;
1438 }
1439 }
1440
1441 bufobj_wwait(bo, 0, 0);
1442 BO_UNLOCK(bo);
1443 vnode_pager_setsize(vp, length);
1444
1445 return (0);
1446 }
1447
1448 /*
1449 * buf_splay() - splay tree core for the clean/dirty list of buffers in
1450 * a vnode.
1451 *
1452 * NOTE: We have to deal with the special case of a background bitmap
1453 * buffer, a situation where two buffers will have the same logical
1454 * block offset. We want (1) only the foreground buffer to be accessed
1455 * in a lookup and (2) must differentiate between the foreground and
1456 * background buffer in the splay tree algorithm because the splay
1457 * tree cannot normally handle multiple entities with the same 'index'.
1458 * We accomplish this by adding differentiating flags to the splay tree's
1459 * numerical domain.
1460 */
1461 static
1462 struct buf *
1463 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root)
1464 {
1465 struct buf dummy;
1466 struct buf *lefttreemax, *righttreemin, *y;
1467
1468 if (root == NULL)
1469 return (NULL);
1470 lefttreemax = righttreemin = &dummy;
1471 for (;;) {
1472 if (lblkno < root->b_lblkno ||
1473 (lblkno == root->b_lblkno &&
1474 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1475 if ((y = root->b_left) == NULL)
1476 break;
1477 if (lblkno < y->b_lblkno) {
1478 /* Rotate right. */
1479 root->b_left = y->b_right;
1480 y->b_right = root;
1481 root = y;
1482 if ((y = root->b_left) == NULL)
1483 break;
1484 }
1485 /* Link into the new root's right tree. */
1486 righttreemin->b_left = root;
1487 righttreemin = root;
1488 } else if (lblkno > root->b_lblkno ||
1489 (lblkno == root->b_lblkno &&
1490 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) {
1491 if ((y = root->b_right) == NULL)
1492 break;
1493 if (lblkno > y->b_lblkno) {
1494 /* Rotate left. */
1495 root->b_right = y->b_left;
1496 y->b_left = root;
1497 root = y;
1498 if ((y = root->b_right) == NULL)
1499 break;
1500 }
1501 /* Link into the new root's left tree. */
1502 lefttreemax->b_right = root;
1503 lefttreemax = root;
1504 } else {
1505 break;
1506 }
1507 root = y;
1508 }
1509 /* Assemble the new root. */
1510 lefttreemax->b_right = root->b_left;
1511 righttreemin->b_left = root->b_right;
1512 root->b_left = dummy.b_right;
1513 root->b_right = dummy.b_left;
1514 return (root);
1515 }
1516
1517 static void
1518 buf_vlist_remove(struct buf *bp)
1519 {
1520 struct buf *root;
1521 struct bufv *bv;
1522
1523 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1524 ASSERT_BO_LOCKED(bp->b_bufobj);
1525 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1526 (BX_VNDIRTY|BX_VNCLEAN),
1527 ("buf_vlist_remove: Buf %p is on two lists", bp));
1528 if (bp->b_xflags & BX_VNDIRTY)
1529 bv = &bp->b_bufobj->bo_dirty;
1530 else
1531 bv = &bp->b_bufobj->bo_clean;
1532 if (bp != bv->bv_root) {
1533 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1534 KASSERT(root == bp, ("splay lookup failed in remove"));
1535 }
1536 if (bp->b_left == NULL) {
1537 root = bp->b_right;
1538 } else {
1539 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left);
1540 root->b_right = bp->b_right;
1541 }
1542 bv->bv_root = root;
1543 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1544 bv->bv_cnt--;
1545 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1546 }
1547
1548 /*
1549 * Add the buffer to the sorted clean or dirty block list using a
1550 * splay tree algorithm.
1551 *
1552 * NOTE: xflags is passed as a constant, optimizing this inline function!
1553 */
1554 static void
1555 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1556 {
1557 struct buf *root;
1558 struct bufv *bv;
1559
1560 ASSERT_BO_LOCKED(bo);
1561 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1562 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1563 bp->b_xflags |= xflags;
1564 if (xflags & BX_VNDIRTY)
1565 bv = &bo->bo_dirty;
1566 else
1567 bv = &bo->bo_clean;
1568
1569 root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root);
1570 if (root == NULL) {
1571 bp->b_left = NULL;
1572 bp->b_right = NULL;
1573 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1574 } else if (bp->b_lblkno < root->b_lblkno ||
1575 (bp->b_lblkno == root->b_lblkno &&
1576 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) {
1577 bp->b_left = root->b_left;
1578 bp->b_right = root;
1579 root->b_left = NULL;
1580 TAILQ_INSERT_BEFORE(root, bp, b_bobufs);
1581 } else {
1582 bp->b_right = root->b_right;
1583 bp->b_left = root;
1584 root->b_right = NULL;
1585 TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs);
1586 }
1587 bv->bv_cnt++;
1588 bv->bv_root = bp;
1589 }
1590
1591 /*
1592 * Lookup a buffer using the splay tree. Note that we specifically avoid
1593 * shadow buffers used in background bitmap writes.
1594 *
1595 * This code isn't quite efficient as it could be because we are maintaining
1596 * two sorted lists and do not know which list the block resides in.
1597 *
1598 * During a "make buildworld" the desired buffer is found at one of
1599 * the roots more than 60% of the time. Thus, checking both roots
1600 * before performing either splay eliminates unnecessary splays on the
1601 * first tree splayed.
1602 */
1603 struct buf *
1604 gbincore(struct bufobj *bo, daddr_t lblkno)
1605 {
1606 struct buf *bp;
1607
1608 ASSERT_BO_LOCKED(bo);
1609 if ((bp = bo->bo_clean.bv_root) != NULL &&
1610 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1611 return (bp);
1612 if ((bp = bo->bo_dirty.bv_root) != NULL &&
1613 bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1614 return (bp);
1615 if ((bp = bo->bo_clean.bv_root) != NULL) {
1616 bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
1617 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1618 return (bp);
1619 }
1620 if ((bp = bo->bo_dirty.bv_root) != NULL) {
1621 bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
1622 if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
1623 return (bp);
1624 }
1625 return (NULL);
1626 }
1627
1628 /*
1629 * Associate a buffer with a vnode.
1630 */
1631 void
1632 bgetvp(struct vnode *vp, struct buf *bp)
1633 {
1634 struct bufobj *bo;
1635
1636 bo = &vp->v_bufobj;
1637 ASSERT_BO_LOCKED(bo);
1638 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1639
1640 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1641 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1642 ("bgetvp: bp already attached! %p", bp));
1643
1644 vhold(vp);
1645 if (VFS_NEEDSGIANT(vp->v_mount) || bo->bo_flag & BO_NEEDSGIANT)
1646 bp->b_flags |= B_NEEDSGIANT;
1647 bp->b_vp = vp;
1648 bp->b_bufobj = bo;
1649 /*
1650 * Insert onto list for new vnode.
1651 */
1652 buf_vlist_add(bp, bo, BX_VNCLEAN);
1653 }
1654
1655 /*
1656 * Disassociate a buffer from a vnode.
1657 */
1658 void
1659 brelvp(struct buf *bp)
1660 {
1661 struct bufobj *bo;
1662 struct vnode *vp;
1663
1664 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1665 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1666
1667 /*
1668 * Delete from old vnode list, if on one.
1669 */
1670 vp = bp->b_vp; /* XXX */
1671 bo = bp->b_bufobj;
1672 BO_LOCK(bo);
1673 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1674 buf_vlist_remove(bp);
1675 else
1676 panic("brelvp: Buffer %p not on queue.", bp);
1677 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1678 bo->bo_flag &= ~BO_ONWORKLST;
1679 mtx_lock(&sync_mtx);
1680 LIST_REMOVE(bo, bo_synclist);
1681 syncer_worklist_len--;
1682 mtx_unlock(&sync_mtx);
1683 }
1684 bp->b_flags &= ~B_NEEDSGIANT;
1685 bp->b_vp = NULL;
1686 bp->b_bufobj = NULL;
1687 BO_UNLOCK(bo);
1688 vdrop(vp);
1689 }
1690
1691 /*
1692 * Add an item to the syncer work queue.
1693 */
1694 static void
1695 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
1696 {
1697 int queue, slot;
1698
1699 ASSERT_BO_LOCKED(bo);
1700
1701 mtx_lock(&sync_mtx);
1702 if (bo->bo_flag & BO_ONWORKLST)
1703 LIST_REMOVE(bo, bo_synclist);
1704 else {
1705 bo->bo_flag |= BO_ONWORKLST;
1706 syncer_worklist_len++;
1707 }
1708
1709 if (delay > syncer_maxdelay - 2)
1710 delay = syncer_maxdelay - 2;
1711 slot = (syncer_delayno + delay) & syncer_mask;
1712
1713 queue = VFS_NEEDSGIANT(bo->__bo_vnode->v_mount) ? WI_GIANTQ :
1714 WI_MPSAFEQ;
1715 LIST_INSERT_HEAD(&syncer_workitem_pending[queue][slot], bo,
1716 bo_synclist);
1717 mtx_unlock(&sync_mtx);
1718 }
1719
1720 static int
1721 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
1722 {
1723 int error, len;
1724
1725 mtx_lock(&sync_mtx);
1726 len = syncer_worklist_len - sync_vnode_count;
1727 mtx_unlock(&sync_mtx);
1728 error = SYSCTL_OUT(req, &len, sizeof(len));
1729 return (error);
1730 }
1731
1732 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
1733 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
1734
1735 static struct proc *updateproc;
1736 static void sched_sync(void);
1737 static struct kproc_desc up_kp = {
1738 "syncer",
1739 sched_sync,
1740 &updateproc
1741 };
1742 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
1743
1744 static int
1745 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
1746 {
1747 struct vnode *vp;
1748 struct mount *mp;
1749
1750 *bo = LIST_FIRST(slp);
1751 if (*bo == NULL)
1752 return (0);
1753 vp = (*bo)->__bo_vnode; /* XXX */
1754 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
1755 return (1);
1756 /*
1757 * We use vhold in case the vnode does not
1758 * successfully sync. vhold prevents the vnode from
1759 * going away when we unlock the sync_mtx so that
1760 * we can acquire the vnode interlock.
1761 */
1762 vholdl(vp);
1763 mtx_unlock(&sync_mtx);
1764 VI_UNLOCK(vp);
1765 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1766 vdrop(vp);
1767 mtx_lock(&sync_mtx);
1768 return (*bo == LIST_FIRST(slp));
1769 }
1770 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1771 (void) VOP_FSYNC(vp, MNT_LAZY, td);
1772 VOP_UNLOCK(vp, 0);
1773 vn_finished_write(mp);
1774 BO_LOCK(*bo);
1775 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
1776 /*
1777 * Put us back on the worklist. The worklist
1778 * routine will remove us from our current
1779 * position and then add us back in at a later
1780 * position.
1781 */
1782 vn_syncer_add_to_worklist(*bo, syncdelay);
1783 }
1784 BO_UNLOCK(*bo);
1785 vdrop(vp);
1786 mtx_lock(&sync_mtx);
1787 return (0);
1788 }
1789
1790 /*
1791 * System filesystem synchronizer daemon.
1792 */
1793 static void
1794 sched_sync(void)
1795 {
1796 struct synclist *gnext, *next;
1797 struct synclist *gslp, *slp;
1798 struct bufobj *bo;
1799 long starttime;
1800 struct thread *td = curthread;
1801 int last_work_seen;
1802 int net_worklist_len;
1803 int syncer_final_iter;
1804 int first_printf;
1805 int error;
1806
1807 last_work_seen = 0;
1808 syncer_final_iter = 0;
1809 first_printf = 1;
1810 syncer_state = SYNCER_RUNNING;
1811 starttime = time_uptime;
1812 td->td_pflags |= TDP_NORUNNINGBUF;
1813
1814 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
1815 SHUTDOWN_PRI_LAST);
1816
1817 mtx_lock(&sync_mtx);
1818 for (;;) {
1819 if (syncer_state == SYNCER_FINAL_DELAY &&
1820 syncer_final_iter == 0) {
1821 mtx_unlock(&sync_mtx);
1822 kproc_suspend_check(td->td_proc);
1823 mtx_lock(&sync_mtx);
1824 }
1825 net_worklist_len = syncer_worklist_len - sync_vnode_count;
1826 if (syncer_state != SYNCER_RUNNING &&
1827 starttime != time_uptime) {
1828 if (first_printf) {
1829 printf("\nSyncing disks, vnodes remaining...");
1830 first_printf = 0;
1831 }
1832 printf("%d ", net_worklist_len);
1833 }
1834 starttime = time_uptime;
1835
1836 /*
1837 * Push files whose dirty time has expired. Be careful
1838 * of interrupt race on slp queue.
1839 *
1840 * Skip over empty worklist slots when shutting down.
1841 */
1842 do {
1843 slp = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno];
1844 gslp = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno];
1845 syncer_delayno += 1;
1846 if (syncer_delayno == syncer_maxdelay)
1847 syncer_delayno = 0;
1848 next = &syncer_workitem_pending[WI_MPSAFEQ][syncer_delayno];
1849 gnext = &syncer_workitem_pending[WI_GIANTQ][syncer_delayno];
1850 /*
1851 * If the worklist has wrapped since the
1852 * it was emptied of all but syncer vnodes,
1853 * switch to the FINAL_DELAY state and run
1854 * for one more second.
1855 */
1856 if (syncer_state == SYNCER_SHUTTING_DOWN &&
1857 net_worklist_len == 0 &&
1858 last_work_seen == syncer_delayno) {
1859 syncer_state = SYNCER_FINAL_DELAY;
1860 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
1861 }
1862 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
1863 LIST_EMPTY(gslp) && syncer_worklist_len > 0);
1864
1865 /*
1866 * Keep track of the last time there was anything
1867 * on the worklist other than syncer vnodes.
1868 * Return to the SHUTTING_DOWN state if any
1869 * new work appears.
1870 */
1871 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
1872 last_work_seen = syncer_delayno;
1873 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
1874 syncer_state = SYNCER_SHUTTING_DOWN;
1875 while (!LIST_EMPTY(slp)) {
1876 error = sync_vnode(slp, &bo, td);
1877 if (error == 1) {
1878 LIST_REMOVE(bo, bo_synclist);
1879 LIST_INSERT_HEAD(next, bo, bo_synclist);
1880 continue;
1881 }
1882 #ifdef SW_WATCHDOG
1883 if (first_printf == 0)
1884 wdog_kern_pat(WD_LASTVAL);
1885 #endif
1886 }
1887 if (!LIST_EMPTY(gslp)) {
1888 mtx_unlock(&sync_mtx);
1889 mtx_lock(&Giant);
1890 mtx_lock(&sync_mtx);
1891 while (!LIST_EMPTY(gslp)) {
1892 error = sync_vnode(gslp, &bo, td);
1893 if (error == 1) {
1894 LIST_REMOVE(bo, bo_synclist);
1895 LIST_INSERT_HEAD(gnext, bo,
1896 bo_synclist);
1897 continue;
1898 }
1899 }
1900 mtx_unlock(&Giant);
1901 }
1902 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
1903 syncer_final_iter--;
1904 /*
1905 * The variable rushjob allows the kernel to speed up the
1906 * processing of the filesystem syncer process. A rushjob
1907 * value of N tells the filesystem syncer to process the next
1908 * N seconds worth of work on its queue ASAP. Currently rushjob
1909 * is used by the soft update code to speed up the filesystem
1910 * syncer process when the incore state is getting so far
1911 * ahead of the disk that the kernel memory pool is being
1912 * threatened with exhaustion.
1913 */
1914 if (rushjob > 0) {
1915 rushjob -= 1;
1916 continue;
1917 }
1918 /*
1919 * Just sleep for a short period of time between
1920 * iterations when shutting down to allow some I/O
1921 * to happen.
1922 *
1923 * If it has taken us less than a second to process the
1924 * current work, then wait. Otherwise start right over
1925 * again. We can still lose time if any single round
1926 * takes more than two seconds, but it does not really
1927 * matter as we are just trying to generally pace the
1928 * filesystem activity.
1929 */
1930 if (syncer_state != SYNCER_RUNNING ||
1931 time_uptime == starttime) {
1932 thread_lock(td);
1933 sched_prio(td, PPAUSE);
1934 thread_unlock(td);
1935 }
1936 if (syncer_state != SYNCER_RUNNING)
1937 cv_timedwait(&sync_wakeup, &sync_mtx,
1938 hz / SYNCER_SHUTDOWN_SPEEDUP);
1939 else if (time_uptime == starttime)
1940 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
1941 }
1942 }
1943
1944 /*
1945 * Request the syncer daemon to speed up its work.
1946 * We never push it to speed up more than half of its
1947 * normal turn time, otherwise it could take over the cpu.
1948 */
1949 int
1950 speedup_syncer(void)
1951 {
1952 int ret = 0;
1953
1954 mtx_lock(&sync_mtx);
1955 if (rushjob < syncdelay / 2) {
1956 rushjob += 1;
1957 stat_rush_requests += 1;
1958 ret = 1;
1959 }
1960 mtx_unlock(&sync_mtx);
1961 cv_broadcast(&sync_wakeup);
1962 return (ret);
1963 }
1964
1965 /*
1966 * Tell the syncer to speed up its work and run though its work
1967 * list several times, then tell it to shut down.
1968 */
1969 static void
1970 syncer_shutdown(void *arg, int howto)
1971 {
1972
1973 if (howto & RB_NOSYNC)
1974 return;
1975 mtx_lock(&sync_mtx);
1976 syncer_state = SYNCER_SHUTTING_DOWN;
1977 rushjob = 0;
1978 mtx_unlock(&sync_mtx);
1979 cv_broadcast(&sync_wakeup);
1980 kproc_shutdown(arg, howto);
1981 }
1982
1983 /*
1984 * Reassign a buffer from one vnode to another.
1985 * Used to assign file specific control information
1986 * (indirect blocks) to the vnode to which they belong.
1987 */
1988 void
1989 reassignbuf(struct buf *bp)
1990 {
1991 struct vnode *vp;
1992 struct bufobj *bo;
1993 int delay;
1994 #ifdef INVARIANTS
1995 struct bufv *bv;
1996 #endif
1997
1998 vp = bp->b_vp;
1999 bo = bp->b_bufobj;
2000 ++reassignbufcalls;
2001
2002 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
2003 bp, bp->b_vp, bp->b_flags);
2004 /*
2005 * B_PAGING flagged buffers cannot be reassigned because their vp
2006 * is not fully linked in.
2007 */
2008 if (bp->b_flags & B_PAGING)
2009 panic("cannot reassign paging buffer");
2010
2011 /*
2012 * Delete from old vnode list, if on one.
2013 */
2014 BO_LOCK(bo);
2015 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2016 buf_vlist_remove(bp);
2017 else
2018 panic("reassignbuf: Buffer %p not on queue.", bp);
2019 /*
2020 * If dirty, put on list of dirty buffers; otherwise insert onto list
2021 * of clean buffers.
2022 */
2023 if (bp->b_flags & B_DELWRI) {
2024 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
2025 switch (vp->v_type) {
2026 case VDIR:
2027 delay = dirdelay;
2028 break;
2029 case VCHR:
2030 delay = metadelay;
2031 break;
2032 default:
2033 delay = filedelay;
2034 }
2035 vn_syncer_add_to_worklist(bo, delay);
2036 }
2037 buf_vlist_add(bp, bo, BX_VNDIRTY);
2038 } else {
2039 buf_vlist_add(bp, bo, BX_VNCLEAN);
2040
2041 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2042 mtx_lock(&sync_mtx);
2043 LIST_REMOVE(bo, bo_synclist);
2044 syncer_worklist_len--;
2045 mtx_unlock(&sync_mtx);
2046 bo->bo_flag &= ~BO_ONWORKLST;
2047 }
2048 }
2049 #ifdef INVARIANTS
2050 bv = &bo->bo_clean;
2051 bp = TAILQ_FIRST(&bv->bv_hd);
2052 KASSERT(bp == NULL || bp->b_bufobj == bo,
2053 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2054 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2055 KASSERT(bp == NULL || bp->b_bufobj == bo,
2056 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2057 bv = &bo->bo_dirty;
2058 bp = TAILQ_FIRST(&bv->bv_hd);
2059 KASSERT(bp == NULL || bp->b_bufobj == bo,
2060 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2061 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2062 KASSERT(bp == NULL || bp->b_bufobj == bo,
2063 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2064 #endif
2065 BO_UNLOCK(bo);
2066 }
2067
2068 /*
2069 * Increment the use and hold counts on the vnode, taking care to reference
2070 * the driver's usecount if this is a chardev. The vholdl() will remove
2071 * the vnode from the free list if it is presently free. Requires the
2072 * vnode interlock and returns with it held.
2073 */
2074 static void
2075 v_incr_usecount(struct vnode *vp)
2076 {
2077
2078 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2079 vp->v_usecount++;
2080 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2081 dev_lock();
2082 vp->v_rdev->si_usecount++;
2083 dev_unlock();
2084 }
2085 vholdl(vp);
2086 }
2087
2088 /*
2089 * Turn a holdcnt into a use+holdcnt such that only one call to
2090 * v_decr_usecount is needed.
2091 */
2092 static void
2093 v_upgrade_usecount(struct vnode *vp)
2094 {
2095
2096 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2097 vp->v_usecount++;
2098 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2099 dev_lock();
2100 vp->v_rdev->si_usecount++;
2101 dev_unlock();
2102 }
2103 }
2104
2105 /*
2106 * Decrement the vnode use and hold count along with the driver's usecount
2107 * if this is a chardev. The vdropl() below releases the vnode interlock
2108 * as it may free the vnode.
2109 */
2110 static void
2111 v_decr_usecount(struct vnode *vp)
2112 {
2113
2114 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2115 VNASSERT(vp->v_usecount > 0, vp,
2116 ("v_decr_usecount: negative usecount"));
2117 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2118 vp->v_usecount--;
2119 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2120 dev_lock();
2121 vp->v_rdev->si_usecount--;
2122 dev_unlock();
2123 }
2124 vdropl(vp);
2125 }
2126
2127 /*
2128 * Decrement only the use count and driver use count. This is intended to
2129 * be paired with a follow on vdropl() to release the remaining hold count.
2130 * In this way we may vgone() a vnode with a 0 usecount without risk of
2131 * having it end up on a free list because the hold count is kept above 0.
2132 */
2133 static void
2134 v_decr_useonly(struct vnode *vp)
2135 {
2136
2137 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2138 VNASSERT(vp->v_usecount > 0, vp,
2139 ("v_decr_useonly: negative usecount"));
2140 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2141 vp->v_usecount--;
2142 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2143 dev_lock();
2144 vp->v_rdev->si_usecount--;
2145 dev_unlock();
2146 }
2147 }
2148
2149 /*
2150 * Grab a particular vnode from the free list, increment its
2151 * reference count and lock it. VI_DOOMED is set if the vnode
2152 * is being destroyed. Only callers who specify LK_RETRY will
2153 * see doomed vnodes. If inactive processing was delayed in
2154 * vput try to do it here.
2155 */
2156 int
2157 vget(struct vnode *vp, int flags, struct thread *td)
2158 {
2159 int error;
2160
2161 error = 0;
2162 VFS_ASSERT_GIANT(vp->v_mount);
2163 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2164 ("vget: invalid lock operation"));
2165 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2166
2167 if ((flags & LK_INTERLOCK) == 0)
2168 VI_LOCK(vp);
2169 vholdl(vp);
2170 if ((error = vn_lock(vp, flags | LK_INTERLOCK)) != 0) {
2171 vdrop(vp);
2172 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2173 vp);
2174 return (error);
2175 }
2176 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2177 panic("vget: vn_lock failed to return ENOENT\n");
2178 VI_LOCK(vp);
2179 /* Upgrade our holdcnt to a usecount. */
2180 v_upgrade_usecount(vp);
2181 /*
2182 * We don't guarantee that any particular close will
2183 * trigger inactive processing so just make a best effort
2184 * here at preventing a reference to a removed file. If
2185 * we don't succeed no harm is done.
2186 */
2187 if (vp->v_iflag & VI_OWEINACT) {
2188 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2189 (flags & LK_NOWAIT) == 0)
2190 vinactive(vp, td);
2191 vp->v_iflag &= ~VI_OWEINACT;
2192 }
2193 VI_UNLOCK(vp);
2194 return (0);
2195 }
2196
2197 /*
2198 * Increase the reference count of a vnode.
2199 */
2200 void
2201 vref(struct vnode *vp)
2202 {
2203
2204 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2205 VI_LOCK(vp);
2206 v_incr_usecount(vp);
2207 VI_UNLOCK(vp);
2208 }
2209
2210 /*
2211 * Return reference count of a vnode.
2212 *
2213 * The results of this call are only guaranteed when some mechanism other
2214 * than the VI lock is used to stop other processes from gaining references
2215 * to the vnode. This may be the case if the caller holds the only reference.
2216 * This is also useful when stale data is acceptable as race conditions may
2217 * be accounted for by some other means.
2218 */
2219 int
2220 vrefcnt(struct vnode *vp)
2221 {
2222 int usecnt;
2223
2224 VI_LOCK(vp);
2225 usecnt = vp->v_usecount;
2226 VI_UNLOCK(vp);
2227
2228 return (usecnt);
2229 }
2230
2231 #define VPUTX_VRELE 1
2232 #define VPUTX_VPUT 2
2233 #define VPUTX_VUNREF 3
2234
2235 static void
2236 vputx(struct vnode *vp, int func)
2237 {
2238 int error;
2239
2240 KASSERT(vp != NULL, ("vputx: null vp"));
2241 if (func == VPUTX_VUNREF)
2242 ASSERT_VOP_LOCKED(vp, "vunref");
2243 else if (func == VPUTX_VPUT)
2244 ASSERT_VOP_LOCKED(vp, "vput");
2245 else
2246 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2247 VFS_ASSERT_GIANT(vp->v_mount);
2248 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2249 VI_LOCK(vp);
2250
2251 /* Skip this v_writecount check if we're going to panic below. */
2252 VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
2253 ("vputx: missed vn_close"));
2254 error = 0;
2255
2256 if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
2257 vp->v_usecount == 1)) {
2258 if (func == VPUTX_VPUT)
2259 VOP_UNLOCK(vp, 0);
2260 v_decr_usecount(vp);
2261 return;
2262 }
2263
2264 if (vp->v_usecount != 1) {
2265 vprint("vputx: negative ref count", vp);
2266 panic("vputx: negative ref cnt");
2267 }
2268 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
2269 /*
2270 * We want to hold the vnode until the inactive finishes to
2271 * prevent vgone() races. We drop the use count here and the
2272 * hold count below when we're done.
2273 */
2274 v_decr_useonly(vp);
2275 /*
2276 * We must call VOP_INACTIVE with the node locked. Mark
2277 * as VI_DOINGINACT to avoid recursion.
2278 */
2279 vp->v_iflag |= VI_OWEINACT;
2280 switch (func) {
2281 case VPUTX_VRELE:
2282 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2283 VI_LOCK(vp);
2284 break;
2285 case VPUTX_VPUT:
2286 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2287 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
2288 LK_NOWAIT);
2289 VI_LOCK(vp);
2290 }
2291 break;
2292 case VPUTX_VUNREF:
2293 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
2294 error = EBUSY;
2295 break;
2296 }
2297 if (vp->v_usecount > 0)
2298 vp->v_iflag &= ~VI_OWEINACT;
2299 if (error == 0) {
2300 if (vp->v_iflag & VI_OWEINACT)
2301 vinactive(vp, curthread);
2302 if (func != VPUTX_VUNREF)
2303 VOP_UNLOCK(vp, 0);
2304 }
2305 vdropl(vp);
2306 }
2307
2308 /*
2309 * Vnode put/release.
2310 * If count drops to zero, call inactive routine and return to freelist.
2311 */
2312 void
2313 vrele(struct vnode *vp)
2314 {
2315
2316 vputx(vp, VPUTX_VRELE);
2317 }
2318
2319 /*
2320 * Release an already locked vnode. This give the same effects as
2321 * unlock+vrele(), but takes less time and avoids releasing and
2322 * re-aquiring the lock (as vrele() acquires the lock internally.)
2323 */
2324 void
2325 vput(struct vnode *vp)
2326 {
2327
2328 vputx(vp, VPUTX_VPUT);
2329 }
2330
2331 /*
2332 * Release an exclusively locked vnode. Do not unlock the vnode lock.
2333 */
2334 void
2335 vunref(struct vnode *vp)
2336 {
2337
2338 vputx(vp, VPUTX_VUNREF);
2339 }
2340
2341 /*
2342 * Somebody doesn't want the vnode recycled.
2343 */
2344 void
2345 vhold(struct vnode *vp)
2346 {
2347
2348 VI_LOCK(vp);
2349 vholdl(vp);
2350 VI_UNLOCK(vp);
2351 }
2352
2353 void
2354 vholdl(struct vnode *vp)
2355 {
2356
2357 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2358 vp->v_holdcnt++;
2359 if (VSHOULDBUSY(vp))
2360 vbusy(vp);
2361 }
2362
2363 /*
2364 * Note that there is one less who cares about this vnode. vdrop() is the
2365 * opposite of vhold().
2366 */
2367 void
2368 vdrop(struct vnode *vp)
2369 {
2370
2371 VI_LOCK(vp);
2372 vdropl(vp);
2373 }
2374
2375 /*
2376 * Drop the hold count of the vnode. If this is the last reference to
2377 * the vnode we will free it if it has been vgone'd otherwise it is
2378 * placed on the free list.
2379 */
2380 void
2381 vdropl(struct vnode *vp)
2382 {
2383
2384 ASSERT_VI_LOCKED(vp, "vdropl");
2385 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2386 if (vp->v_holdcnt <= 0)
2387 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2388 vp->v_holdcnt--;
2389 if (vp->v_holdcnt == 0) {
2390 if (vp->v_iflag & VI_DOOMED) {
2391 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__,
2392 vp);
2393 vdestroy(vp);
2394 return;
2395 } else
2396 vfree(vp);
2397 }
2398 VI_UNLOCK(vp);
2399 }
2400
2401 /*
2402 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2403 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2404 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2405 * failed lock upgrade.
2406 */
2407 static void
2408 vinactive(struct vnode *vp, struct thread *td)
2409 {
2410
2411 ASSERT_VOP_ELOCKED(vp, "vinactive");
2412 ASSERT_VI_LOCKED(vp, "vinactive");
2413 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2414 ("vinactive: recursed on VI_DOINGINACT"));
2415 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2416 vp->v_iflag |= VI_DOINGINACT;
2417 vp->v_iflag &= ~VI_OWEINACT;
2418 VI_UNLOCK(vp);
2419 VOP_INACTIVE(vp, td);
2420 VI_LOCK(vp);
2421 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2422 ("vinactive: lost VI_DOINGINACT"));
2423 vp->v_iflag &= ~VI_DOINGINACT;
2424 }
2425
2426 /*
2427 * Remove any vnodes in the vnode table belonging to mount point mp.
2428 *
2429 * If FORCECLOSE is not specified, there should not be any active ones,
2430 * return error if any are found (nb: this is a user error, not a
2431 * system error). If FORCECLOSE is specified, detach any active vnodes
2432 * that are found.
2433 *
2434 * If WRITECLOSE is set, only flush out regular file vnodes open for
2435 * writing.
2436 *
2437 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2438 *
2439 * `rootrefs' specifies the base reference count for the root vnode
2440 * of this filesystem. The root vnode is considered busy if its
2441 * v_usecount exceeds this value. On a successful return, vflush(, td)
2442 * will call vrele() on the root vnode exactly rootrefs times.
2443 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2444 * be zero.
2445 */
2446 #ifdef DIAGNOSTIC
2447 static int busyprt = 0; /* print out busy vnodes */
2448 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
2449 #endif
2450
2451 int
2452 vflush( struct mount *mp, int rootrefs, int flags, struct thread *td)
2453 {
2454 struct vnode *vp, *mvp, *rootvp = NULL;
2455 struct vattr vattr;
2456 int busy = 0, error;
2457
2458 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
2459 rootrefs, flags);
2460 if (rootrefs > 0) {
2461 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2462 ("vflush: bad args"));
2463 /*
2464 * Get the filesystem root vnode. We can vput() it
2465 * immediately, since with rootrefs > 0, it won't go away.
2466 */
2467 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
2468 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
2469 __func__, error);
2470 return (error);
2471 }
2472 vput(rootvp);
2473
2474 }
2475 MNT_ILOCK(mp);
2476 loop:
2477 MNT_VNODE_FOREACH(vp, mp, mvp) {
2478
2479 VI_LOCK(vp);
2480 vholdl(vp);
2481 MNT_IUNLOCK(mp);
2482 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
2483 if (error) {
2484 vdrop(vp);
2485 MNT_ILOCK(mp);
2486 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
2487 goto loop;
2488 }
2489 /*
2490 * Skip over a vnodes marked VV_SYSTEM.
2491 */
2492 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2493 VOP_UNLOCK(vp, 0);
2494 vdrop(vp);
2495 MNT_ILOCK(mp);
2496 continue;
2497 }
2498 /*
2499 * If WRITECLOSE is set, flush out unlinked but still open
2500 * files (even if open only for reading) and regular file
2501 * vnodes open for writing.
2502 */
2503 if (flags & WRITECLOSE) {
2504 if (vp->v_object != NULL) {
2505 VM_OBJECT_LOCK(vp->v_object);
2506 vm_object_page_clean(vp->v_object, 0, 0, 0);
2507 VM_OBJECT_UNLOCK(vp->v_object);
2508 }
2509 error = VOP_FSYNC(vp, MNT_WAIT, td);
2510 if (error != 0) {
2511 VOP_UNLOCK(vp, 0);
2512 vdrop(vp);
2513 MNT_VNODE_FOREACH_ABORT(mp, mvp);
2514 return (error);
2515 }
2516 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
2517 VI_LOCK(vp);
2518
2519 if ((vp->v_type == VNON ||
2520 (error == 0 && vattr.va_nlink > 0)) &&
2521 (vp->v_writecount == 0 || vp->v_type != VREG)) {
2522 VOP_UNLOCK(vp, 0);
2523 vdropl(vp);
2524 MNT_ILOCK(mp);
2525 continue;
2526 }
2527 } else
2528 VI_LOCK(vp);
2529 /*
2530 * With v_usecount == 0, all we need to do is clear out the
2531 * vnode data structures and we are done.
2532 *
2533 * If FORCECLOSE is set, forcibly close the vnode.
2534 */
2535 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
2536 VNASSERT(vp->v_usecount == 0 ||
2537 (vp->v_type != VCHR && vp->v_type != VBLK), vp,
2538 ("device VNODE %p is FORCECLOSED", vp));
2539 vgonel(vp);
2540 } else {
2541 busy++;
2542 #ifdef DIAGNOSTIC
2543 if (busyprt)
2544 vprint("vflush: busy vnode", vp);
2545 #endif
2546 }
2547 VOP_UNLOCK(vp, 0);
2548 vdropl(vp);
2549 MNT_ILOCK(mp);
2550 }
2551 MNT_IUNLOCK(mp);
2552 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
2553 /*
2554 * If just the root vnode is busy, and if its refcount
2555 * is equal to `rootrefs', then go ahead and kill it.
2556 */
2557 VI_LOCK(rootvp);
2558 KASSERT(busy > 0, ("vflush: not busy"));
2559 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
2560 ("vflush: usecount %d < rootrefs %d",
2561 rootvp->v_usecount, rootrefs));
2562 if (busy == 1 && rootvp->v_usecount == rootrefs) {
2563 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
2564 vgone(rootvp);
2565 VOP_UNLOCK(rootvp, 0);
2566 busy = 0;
2567 } else
2568 VI_UNLOCK(rootvp);
2569 }
2570 if (busy) {
2571 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
2572 busy);
2573 return (EBUSY);
2574 }
2575 for (; rootrefs > 0; rootrefs--)
2576 vrele(rootvp);
2577 return (0);
2578 }
2579
2580 /*
2581 * Recycle an unused vnode to the front of the free list.
2582 */
2583 int
2584 vrecycle(struct vnode *vp, struct thread *td)
2585 {
2586 int recycled;
2587
2588 ASSERT_VOP_ELOCKED(vp, "vrecycle");
2589 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2590 recycled = 0;
2591 VI_LOCK(vp);
2592 if (vp->v_usecount == 0) {
2593 recycled = 1;
2594 vgonel(vp);
2595 }
2596 VI_UNLOCK(vp);
2597 return (recycled);
2598 }
2599
2600 /*
2601 * Eliminate all activity associated with a vnode
2602 * in preparation for reuse.
2603 */
2604 void
2605 vgone(struct vnode *vp)
2606 {
2607 VI_LOCK(vp);
2608 vgonel(vp);
2609 VI_UNLOCK(vp);
2610 }
2611
2612 /*
2613 * vgone, with the vp interlock held.
2614 */
2615 void
2616 vgonel(struct vnode *vp)
2617 {
2618 struct thread *td;
2619 int oweinact;
2620 int active;
2621 struct mount *mp;
2622
2623 ASSERT_VOP_ELOCKED(vp, "vgonel");
2624 ASSERT_VI_LOCKED(vp, "vgonel");
2625 VNASSERT(vp->v_holdcnt, vp,
2626 ("vgonel: vp %p has no reference.", vp));
2627 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2628 td = curthread;
2629
2630 /*
2631 * Don't vgonel if we're already doomed.
2632 */
2633 if (vp->v_iflag & VI_DOOMED)
2634 return;
2635 vp->v_iflag |= VI_DOOMED;
2636 /*
2637 * Check to see if the vnode is in use. If so, we have to call
2638 * VOP_CLOSE() and VOP_INACTIVE().
2639 */
2640 active = vp->v_usecount;
2641 oweinact = (vp->v_iflag & VI_OWEINACT);
2642 VI_UNLOCK(vp);
2643 /*
2644 * Clean out any buffers associated with the vnode.
2645 * If the flush fails, just toss the buffers.
2646 */
2647 mp = NULL;
2648 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
2649 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
2650 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0)
2651 vinvalbuf(vp, 0, 0, 0);
2652
2653 /*
2654 * If purging an active vnode, it must be closed and
2655 * deactivated before being reclaimed.
2656 */
2657 if (active)
2658 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
2659 if (oweinact || active) {
2660 VI_LOCK(vp);
2661 if ((vp->v_iflag & VI_DOINGINACT) == 0)
2662 vinactive(vp, td);
2663 VI_UNLOCK(vp);
2664 }
2665 /*
2666 * Reclaim the vnode.
2667 */
2668 if (VOP_RECLAIM(vp, td))
2669 panic("vgone: cannot reclaim");
2670 if (mp != NULL)
2671 vn_finished_secondary_write(mp);
2672 VNASSERT(vp->v_object == NULL, vp,
2673 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
2674 /*
2675 * Clear the advisory locks and wake up waiting threads.
2676 */
2677 lf_purgelocks(vp, &(vp->v_lockf));
2678 /*
2679 * Delete from old mount point vnode list.
2680 */
2681 delmntque(vp);
2682 cache_purge(vp);
2683 /*
2684 * Done with purge, reset to the standard lock and invalidate
2685 * the vnode.
2686 */
2687 VI_LOCK(vp);
2688 vp->v_vnlock = &vp->v_lock;
2689 vp->v_op = &dead_vnodeops;
2690 vp->v_tag = "none";
2691 vp->v_type = VBAD;
2692 }
2693
2694 /*
2695 * Calculate the total number of references to a special device.
2696 */
2697 int
2698 vcount(struct vnode *vp)
2699 {
2700 int count;
2701
2702 dev_lock();
2703 count = vp->v_rdev->si_usecount;
2704 dev_unlock();
2705 return (count);
2706 }
2707
2708 /*
2709 * Same as above, but using the struct cdev *as argument
2710 */
2711 int
2712 count_dev(struct cdev *dev)
2713 {
2714 int count;
2715
2716 dev_lock();
2717 count = dev->si_usecount;
2718 dev_unlock();
2719 return(count);
2720 }
2721
2722 /*
2723 * Print out a description of a vnode.
2724 */
2725 static char *typename[] =
2726 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
2727 "VMARKER"};
2728
2729 void
2730 vn_printf(struct vnode *vp, const char *fmt, ...)
2731 {
2732 va_list ap;
2733 char buf[256], buf2[16];
2734 u_long flags;
2735
2736 va_start(ap, fmt);
2737 vprintf(fmt, ap);
2738 va_end(ap);
2739 printf("%p: ", (void *)vp);
2740 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
2741 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
2742 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
2743 buf[0] = '\0';
2744 buf[1] = '\0';
2745 if (vp->v_vflag & VV_ROOT)
2746 strlcat(buf, "|VV_ROOT", sizeof(buf));
2747 if (vp->v_vflag & VV_ISTTY)
2748 strlcat(buf, "|VV_ISTTY", sizeof(buf));
2749 if (vp->v_vflag & VV_NOSYNC)
2750 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
2751 if (vp->v_vflag & VV_CACHEDLABEL)
2752 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
2753 if (vp->v_vflag & VV_TEXT)
2754 strlcat(buf, "|VV_TEXT", sizeof(buf));
2755 if (vp->v_vflag & VV_COPYONWRITE)
2756 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
2757 if (vp->v_vflag & VV_SYSTEM)
2758 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
2759 if (vp->v_vflag & VV_PROCDEP)
2760 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
2761 if (vp->v_vflag & VV_NOKNOTE)
2762 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
2763 if (vp->v_vflag & VV_DELETED)
2764 strlcat(buf, "|VV_DELETED", sizeof(buf));
2765 if (vp->v_vflag & VV_MD)
2766 strlcat(buf, "|VV_MD", sizeof(buf));
2767 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC |
2768 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
2769 VV_NOKNOTE | VV_DELETED | VV_MD);
2770 if (flags != 0) {
2771 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
2772 strlcat(buf, buf2, sizeof(buf));
2773 }
2774 if (vp->v_iflag & VI_MOUNT)
2775 strlcat(buf, "|VI_MOUNT", sizeof(buf));
2776 if (vp->v_iflag & VI_AGE)
2777 strlcat(buf, "|VI_AGE", sizeof(buf));
2778 if (vp->v_iflag & VI_DOOMED)
2779 strlcat(buf, "|VI_DOOMED", sizeof(buf));
2780 if (vp->v_iflag & VI_FREE)
2781 strlcat(buf, "|VI_FREE", sizeof(buf));
2782 if (vp->v_iflag & VI_DOINGINACT)
2783 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
2784 if (vp->v_iflag & VI_OWEINACT)
2785 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
2786 flags = vp->v_iflag & ~(VI_MOUNT | VI_AGE | VI_DOOMED | VI_FREE |
2787 VI_DOINGINACT | VI_OWEINACT);
2788 if (flags != 0) {
2789 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
2790 strlcat(buf, buf2, sizeof(buf));
2791 }
2792 printf(" flags (%s)\n", buf + 1);
2793 if (mtx_owned(VI_MTX(vp)))
2794 printf(" VI_LOCKed");
2795 if (vp->v_object != NULL)
2796 printf(" v_object %p ref %d pages %d\n",
2797 vp->v_object, vp->v_object->ref_count,
2798 vp->v_object->resident_page_count);
2799 printf(" ");
2800 lockmgr_printinfo(vp->v_vnlock);
2801 if (vp->v_data != NULL)
2802 VOP_PRINT(vp);
2803 }
2804
2805 #ifdef DDB
2806 /*
2807 * List all of the locked vnodes in the system.
2808 * Called when debugging the kernel.
2809 */
2810 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
2811 {
2812 struct mount *mp, *nmp;
2813 struct vnode *vp;
2814
2815 /*
2816 * Note: because this is DDB, we can't obey the locking semantics
2817 * for these structures, which means we could catch an inconsistent
2818 * state and dereference a nasty pointer. Not much to be done
2819 * about that.
2820 */
2821 db_printf("Locked vnodes\n");
2822 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2823 nmp = TAILQ_NEXT(mp, mnt_list);
2824 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2825 if (vp->v_type != VMARKER &&
2826 VOP_ISLOCKED(vp))
2827 vprint("", vp);
2828 }
2829 nmp = TAILQ_NEXT(mp, mnt_list);
2830 }
2831 }
2832
2833 /*
2834 * Show details about the given vnode.
2835 */
2836 DB_SHOW_COMMAND(vnode, db_show_vnode)
2837 {
2838 struct vnode *vp;
2839
2840 if (!have_addr)
2841 return;
2842 vp = (struct vnode *)addr;
2843 vn_printf(vp, "vnode ");
2844 }
2845
2846 /*
2847 * Show details about the given mount point.
2848 */
2849 DB_SHOW_COMMAND(mount, db_show_mount)
2850 {
2851 struct mount *mp;
2852 struct vfsopt *opt;
2853 struct statfs *sp;
2854 struct vnode *vp;
2855 char buf[512];
2856 u_int flags;
2857
2858 if (!have_addr) {
2859 /* No address given, print short info about all mount points. */
2860 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
2861 db_printf("%p %s on %s (%s)\n", mp,
2862 mp->mnt_stat.f_mntfromname,
2863 mp->mnt_stat.f_mntonname,
2864 mp->mnt_stat.f_fstypename);
2865 if (db_pager_quit)
2866 break;
2867 }
2868 db_printf("\nMore info: show mount <addr>\n");
2869 return;
2870 }
2871
2872 mp = (struct mount *)addr;
2873 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
2874 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
2875
2876 buf[0] = '\0';
2877 flags = mp->mnt_flag;
2878 #define MNT_FLAG(flag) do { \
2879 if (flags & (flag)) { \
2880 if (buf[0] != '\0') \
2881 strlcat(buf, ", ", sizeof(buf)); \
2882 strlcat(buf, (#flag) + 4, sizeof(buf)); \
2883 flags &= ~(flag); \
2884 } \
2885 } while (0)
2886 MNT_FLAG(MNT_RDONLY);
2887 MNT_FLAG(MNT_SYNCHRONOUS);
2888 MNT_FLAG(MNT_NOEXEC);
2889 MNT_FLAG(MNT_NOSUID);
2890 MNT_FLAG(MNT_UNION);
2891 MNT_FLAG(MNT_ASYNC);
2892 MNT_FLAG(MNT_SUIDDIR);
2893 MNT_FLAG(MNT_SOFTDEP);
2894 MNT_FLAG(MNT_NOSYMFOLLOW);
2895 MNT_FLAG(MNT_GJOURNAL);
2896 MNT_FLAG(MNT_MULTILABEL);
2897 MNT_FLAG(MNT_ACLS);
2898 MNT_FLAG(MNT_NOATIME);
2899 MNT_FLAG(MNT_NOCLUSTERR);
2900 MNT_FLAG(MNT_NOCLUSTERW);
2901 MNT_FLAG(MNT_NFS4ACLS);
2902 MNT_FLAG(MNT_EXRDONLY);
2903 MNT_FLAG(MNT_EXPORTED);
2904 MNT_FLAG(MNT_DEFEXPORTED);
2905 MNT_FLAG(MNT_EXPORTANON);
2906 MNT_FLAG(MNT_EXKERB);
2907 MNT_FLAG(MNT_EXPUBLIC);
2908 MNT_FLAG(MNT_LOCAL);
2909 MNT_FLAG(MNT_QUOTA);
2910 MNT_FLAG(MNT_ROOTFS);
2911 MNT_FLAG(MNT_USER);
2912 MNT_FLAG(MNT_IGNORE);
2913 MNT_FLAG(MNT_UPDATE);
2914 MNT_FLAG(MNT_DELEXPORT);
2915 MNT_FLAG(MNT_RELOAD);
2916 MNT_FLAG(MNT_FORCE);
2917 MNT_FLAG(MNT_SNAPSHOT);
2918 MNT_FLAG(MNT_BYFSID);
2919 #undef MNT_FLAG
2920 if (flags != 0) {
2921 if (buf[0] != '\0')
2922 strlcat(buf, ", ", sizeof(buf));
2923 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
2924 "0x%08x", flags);
2925 }
2926 db_printf(" mnt_flag = %s\n", buf);
2927
2928 buf[0] = '\0';
2929 flags = mp->mnt_kern_flag;
2930 #define MNT_KERN_FLAG(flag) do { \
2931 if (flags & (flag)) { \
2932 if (buf[0] != '\0') \
2933 strlcat(buf, ", ", sizeof(buf)); \
2934 strlcat(buf, (#flag) + 5, sizeof(buf)); \
2935 flags &= ~(flag); \
2936 } \
2937 } while (0)
2938 MNT_KERN_FLAG(MNTK_UNMOUNTF);
2939 MNT_KERN_FLAG(MNTK_ASYNC);
2940 MNT_KERN_FLAG(MNTK_SOFTDEP);
2941 MNT_KERN_FLAG(MNTK_NOINSMNTQ);
2942 MNT_KERN_FLAG(MNTK_UNMOUNT);
2943 MNT_KERN_FLAG(MNTK_MWAIT);
2944 MNT_KERN_FLAG(MNTK_SUSPEND);
2945 MNT_KERN_FLAG(MNTK_SUSPEND2);
2946 MNT_KERN_FLAG(MNTK_SUSPENDED);
2947 MNT_KERN_FLAG(MNTK_MPSAFE);
2948 MNT_KERN_FLAG(MNTK_NOKNOTE);
2949 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
2950 #undef MNT_KERN_FLAG
2951 if (flags != 0) {
2952 if (buf[0] != '\0')
2953 strlcat(buf, ", ", sizeof(buf));
2954 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
2955 "0x%08x", flags);
2956 }
2957 db_printf(" mnt_kern_flag = %s\n", buf);
2958
2959 db_printf(" mnt_opt = ");
2960 opt = TAILQ_FIRST(mp->mnt_opt);
2961 if (opt != NULL) {
2962 db_printf("%s", opt->name);
2963 opt = TAILQ_NEXT(opt, link);
2964 while (opt != NULL) {
2965 db_printf(", %s", opt->name);
2966 opt = TAILQ_NEXT(opt, link);
2967 }
2968 }
2969 db_printf("\n");
2970
2971 sp = &mp->mnt_stat;
2972 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
2973 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
2974 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
2975 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
2976 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
2977 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
2978 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
2979 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
2980 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
2981 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
2982 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
2983 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
2984
2985 db_printf(" mnt_cred = { uid=%u ruid=%u",
2986 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
2987 if (jailed(mp->mnt_cred))
2988 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
2989 db_printf(" }\n");
2990 db_printf(" mnt_ref = %d\n", mp->mnt_ref);
2991 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
2992 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
2993 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
2994 db_printf(" mnt_noasync = %u\n", mp->mnt_noasync);
2995 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
2996 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
2997 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
2998 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
2999 db_printf(" mnt_secondary_accwrites = %d\n",
3000 mp->mnt_secondary_accwrites);
3001 db_printf(" mnt_gjprovider = %s\n",
3002 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
3003 db_printf("\n");
3004
3005 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3006 if (vp->v_type != VMARKER) {
3007 vn_printf(vp, "vnode ");
3008 if (db_pager_quit)
3009 break;
3010 }
3011 }
3012 }
3013 #endif /* DDB */
3014
3015 /*
3016 * Fill in a struct xvfsconf based on a struct vfsconf.
3017 */
3018 static void
3019 vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp)
3020 {
3021
3022 strcpy(xvfsp->vfc_name, vfsp->vfc_name);
3023 xvfsp->vfc_typenum = vfsp->vfc_typenum;
3024 xvfsp->vfc_refcount = vfsp->vfc_refcount;
3025 xvfsp->vfc_flags = vfsp->vfc_flags;
3026 /*
3027 * These are unused in userland, we keep them
3028 * to not break binary compatibility.
3029 */
3030 xvfsp->vfc_vfsops = NULL;
3031 xvfsp->vfc_next = NULL;
3032 }
3033
3034 /*
3035 * Top level filesystem related information gathering.
3036 */
3037 static int
3038 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
3039 {
3040 struct vfsconf *vfsp;
3041 struct xvfsconf xvfsp;
3042 int error;
3043
3044 error = 0;
3045 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3046 bzero(&xvfsp, sizeof(xvfsp));
3047 vfsconf2x(vfsp, &xvfsp);
3048 error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp);
3049 if (error)
3050 break;
3051 }
3052 return (error);
3053 }
3054
3055 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist,
3056 "S,xvfsconf", "List of all configured filesystems");
3057
3058 #ifndef BURN_BRIDGES
3059 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
3060
3061 static int
3062 vfs_sysctl(SYSCTL_HANDLER_ARGS)
3063 {
3064 int *name = (int *)arg1 - 1; /* XXX */
3065 u_int namelen = arg2 + 1; /* XXX */
3066 struct vfsconf *vfsp;
3067 struct xvfsconf xvfsp;
3068
3069 printf("WARNING: userland calling deprecated sysctl, "
3070 "please rebuild world\n");
3071
3072 #if 1 || defined(COMPAT_PRELITE2)
3073 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
3074 if (namelen == 1)
3075 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
3076 #endif
3077
3078 switch (name[1]) {
3079 case VFS_MAXTYPENUM:
3080 if (namelen != 2)
3081 return (ENOTDIR);
3082 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
3083 case VFS_CONF:
3084 if (namelen != 3)
3085 return (ENOTDIR); /* overloaded */
3086 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list)
3087 if (vfsp->vfc_typenum == name[2])
3088 break;
3089 if (vfsp == NULL)
3090 return (EOPNOTSUPP);
3091 bzero(&xvfsp, sizeof(xvfsp));
3092 vfsconf2x(vfsp, &xvfsp);
3093 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3094 }
3095 return (EOPNOTSUPP);
3096 }
3097
3098 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP,
3099 vfs_sysctl, "Generic filesystem");
3100
3101 #if 1 || defined(COMPAT_PRELITE2)
3102
3103 static int
3104 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
3105 {
3106 int error;
3107 struct vfsconf *vfsp;
3108 struct ovfsconf ovfs;
3109
3110 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3111 bzero(&ovfs, sizeof(ovfs));
3112 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
3113 strcpy(ovfs.vfc_name, vfsp->vfc_name);
3114 ovfs.vfc_index = vfsp->vfc_typenum;
3115 ovfs.vfc_refcount = vfsp->vfc_refcount;
3116 ovfs.vfc_flags = vfsp->vfc_flags;
3117 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
3118 if (error)
3119 return error;
3120 }
3121 return 0;
3122 }
3123
3124 #endif /* 1 || COMPAT_PRELITE2 */
3125 #endif /* !BURN_BRIDGES */
3126
3127 #define KINFO_VNODESLOP 10
3128 #ifdef notyet
3129 /*
3130 * Dump vnode list (via sysctl).
3131 */
3132 /* ARGSUSED */
3133 static int
3134 sysctl_vnode(SYSCTL_HANDLER_ARGS)
3135 {
3136 struct xvnode *xvn;
3137 struct mount *mp;
3138 struct vnode *vp;
3139 int error, len, n;
3140
3141 /*
3142 * Stale numvnodes access is not fatal here.
3143 */
3144 req->lock = 0;
3145 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
3146 if (!req->oldptr)
3147 /* Make an estimate */
3148 return (SYSCTL_OUT(req, 0, len));
3149
3150 error = sysctl_wire_old_buffer(req, 0);
3151 if (error != 0)
3152 return (error);
3153 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
3154 n = 0;
3155 mtx_lock(&mountlist_mtx);
3156 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3157 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
3158 continue;
3159 MNT_ILOCK(mp);
3160 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3161 if (n == len)
3162 break;
3163 vref(vp);
3164 xvn[n].xv_size = sizeof *xvn;
3165 xvn[n].xv_vnode = vp;
3166 xvn[n].xv_id = 0; /* XXX compat */
3167 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
3168 XV_COPY(usecount);
3169 XV_COPY(writecount);
3170 XV_COPY(holdcnt);
3171 XV_COPY(mount);
3172 XV_COPY(numoutput);
3173 XV_COPY(type);
3174 #undef XV_COPY
3175 xvn[n].xv_flag = vp->v_vflag;
3176
3177 switch (vp->v_type) {
3178 case VREG:
3179 case VDIR:
3180 case VLNK:
3181 break;
3182 case VBLK:
3183 case VCHR:
3184 if (vp->v_rdev == NULL) {
3185 vrele(vp);
3186 continue;
3187 }
3188 xvn[n].xv_dev = dev2udev(vp->v_rdev);
3189 break;
3190 case VSOCK:
3191 xvn[n].xv_socket = vp->v_socket;
3192 break;
3193 case VFIFO:
3194 xvn[n].xv_fifo = vp->v_fifoinfo;
3195 break;
3196 case VNON:
3197 case VBAD:
3198 default:
3199 /* shouldn't happen? */
3200 vrele(vp);
3201 continue;
3202 }
3203 vrele(vp);
3204 ++n;
3205 }
3206 MNT_IUNLOCK(mp);
3207 mtx_lock(&mountlist_mtx);
3208 vfs_unbusy(mp);
3209 if (n == len)
3210 break;
3211 }
3212 mtx_unlock(&mountlist_mtx);
3213
3214 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
3215 free(xvn, M_TEMP);
3216 return (error);
3217 }
3218
3219 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
3220 0, 0, sysctl_vnode, "S,xvnode", "");
3221 #endif
3222
3223 /*
3224 * Unmount all filesystems. The list is traversed in reverse order
3225 * of mounting to avoid dependencies.
3226 */
3227 void
3228 vfs_unmountall(void)
3229 {
3230 struct mount *mp;
3231 struct thread *td;
3232 int error;
3233
3234 KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread"));
3235 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
3236 td = curthread;
3237
3238 /*
3239 * Since this only runs when rebooting, it is not interlocked.
3240 */
3241 while(!TAILQ_EMPTY(&mountlist)) {
3242 mp = TAILQ_LAST(&mountlist, mntlist);
3243 error = dounmount(mp, MNT_FORCE, td);
3244 if (error) {
3245 TAILQ_REMOVE(&mountlist, mp, mnt_list);
3246 /*
3247 * XXX: Due to the way in which we mount the root
3248 * file system off of devfs, devfs will generate a
3249 * "busy" warning when we try to unmount it before
3250 * the root. Don't print a warning as a result in
3251 * order to avoid false positive errors that may
3252 * cause needless upset.
3253 */
3254 if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) {
3255 printf("unmount of %s failed (",
3256 mp->mnt_stat.f_mntonname);
3257 if (error == EBUSY)
3258 printf("BUSY)\n");
3259 else
3260 printf("%d)\n", error);
3261 }
3262 } else {
3263 /* The unmount has removed mp from the mountlist */
3264 }
3265 }
3266 }
3267
3268 /*
3269 * perform msync on all vnodes under a mount point
3270 * the mount point must be locked.
3271 */
3272 void
3273 vfs_msync(struct mount *mp, int flags)
3274 {
3275 struct vnode *vp, *mvp;
3276 struct vm_object *obj;
3277
3278 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
3279 MNT_ILOCK(mp);
3280 MNT_VNODE_FOREACH(vp, mp, mvp) {
3281 VI_LOCK(vp);
3282 obj = vp->v_object;
3283 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
3284 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
3285 MNT_IUNLOCK(mp);
3286 if (!vget(vp,
3287 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
3288 curthread)) {
3289 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
3290 vput(vp);
3291 MNT_ILOCK(mp);
3292 continue;
3293 }
3294
3295 obj = vp->v_object;
3296 if (obj != NULL) {
3297 VM_OBJECT_LOCK(obj);
3298 vm_object_page_clean(obj, 0, 0,
3299 flags == MNT_WAIT ?
3300 OBJPC_SYNC : OBJPC_NOSYNC);
3301 VM_OBJECT_UNLOCK(obj);
3302 }
3303 vput(vp);
3304 }
3305 MNT_ILOCK(mp);
3306 } else
3307 VI_UNLOCK(vp);
3308 }
3309 MNT_IUNLOCK(mp);
3310 }
3311
3312 /*
3313 * Mark a vnode as free, putting it up for recycling.
3314 */
3315 static void
3316 vfree(struct vnode *vp)
3317 {
3318
3319 ASSERT_VI_LOCKED(vp, "vfree");
3320 mtx_lock(&vnode_free_list_mtx);
3321 VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed."));
3322 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free"));
3323 VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't"));
3324 VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp,
3325 ("vfree: Freeing doomed vnode"));
3326 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3327 if (vp->v_iflag & VI_AGE) {
3328 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
3329 } else {
3330 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
3331 }
3332 freevnodes++;
3333 vp->v_iflag &= ~VI_AGE;
3334 vp->v_iflag |= VI_FREE;
3335 mtx_unlock(&vnode_free_list_mtx);
3336 }
3337
3338 /*
3339 * Opposite of vfree() - mark a vnode as in use.
3340 */
3341 static void
3342 vbusy(struct vnode *vp)
3343 {
3344 ASSERT_VI_LOCKED(vp, "vbusy");
3345 VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free"));
3346 VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed."));
3347 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3348
3349 mtx_lock(&vnode_free_list_mtx);
3350 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
3351 freevnodes--;
3352 vp->v_iflag &= ~(VI_FREE|VI_AGE);
3353 mtx_unlock(&vnode_free_list_mtx);
3354 }
3355
3356 static void
3357 destroy_vpollinfo(struct vpollinfo *vi)
3358 {
3359 seldrain(&vi->vpi_selinfo);
3360 knlist_destroy(&vi->vpi_selinfo.si_note);
3361 mtx_destroy(&vi->vpi_lock);
3362 uma_zfree(vnodepoll_zone, vi);
3363 }
3364
3365 /*
3366 * Initalize per-vnode helper structure to hold poll-related state.
3367 */
3368 void
3369 v_addpollinfo(struct vnode *vp)
3370 {
3371 struct vpollinfo *vi;
3372
3373 if (vp->v_pollinfo != NULL)
3374 return;
3375 vi = uma_zalloc(vnodepoll_zone, M_WAITOK);
3376 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
3377 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
3378 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
3379 VI_LOCK(vp);
3380 if (vp->v_pollinfo != NULL) {
3381 VI_UNLOCK(vp);
3382 destroy_vpollinfo(vi);
3383 return;
3384 }
3385 vp->v_pollinfo = vi;
3386 VI_UNLOCK(vp);
3387 }
3388
3389 /*
3390 * Record a process's interest in events which might happen to
3391 * a vnode. Because poll uses the historic select-style interface
3392 * internally, this routine serves as both the ``check for any
3393 * pending events'' and the ``record my interest in future events''
3394 * functions. (These are done together, while the lock is held,
3395 * to avoid race conditions.)
3396 */
3397 int
3398 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
3399 {
3400
3401 v_addpollinfo(vp);
3402 mtx_lock(&vp->v_pollinfo->vpi_lock);
3403 if (vp->v_pollinfo->vpi_revents & events) {
3404 /*
3405 * This leaves events we are not interested
3406 * in available for the other process which
3407 * which presumably had requested them
3408 * (otherwise they would never have been
3409 * recorded).
3410 */
3411 events &= vp->v_pollinfo->vpi_revents;
3412 vp->v_pollinfo->vpi_revents &= ~events;
3413
3414 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3415 return (events);
3416 }
3417 vp->v_pollinfo->vpi_events |= events;
3418 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
3419 mtx_unlock(&vp->v_pollinfo->vpi_lock);
3420 return (0);
3421 }
3422
3423 /*
3424 * Routine to create and manage a filesystem syncer vnode.
3425 */
3426 #define sync_close ((int (*)(struct vop_close_args *))nullop)
3427 static int sync_fsync(struct vop_fsync_args *);
3428 static int sync_inactive(struct vop_inactive_args *);
3429 static int sync_reclaim(struct vop_reclaim_args *);
3430
3431 static struct vop_vector sync_vnodeops = {
3432 .vop_bypass = VOP_EOPNOTSUPP,
3433 .vop_close = sync_close, /* close */
3434 .vop_fsync = sync_fsync, /* fsync */
3435 .vop_inactive = sync_inactive, /* inactive */
3436 .vop_reclaim = sync_reclaim, /* reclaim */
3437 .vop_lock1 = vop_stdlock, /* lock */
3438 .vop_unlock = vop_stdunlock, /* unlock */
3439 .vop_islocked = vop_stdislocked, /* islocked */
3440 };
3441
3442 /*
3443 * Create a new filesystem syncer vnode for the specified mount point.
3444 */
3445 int
3446 vfs_allocate_syncvnode(struct mount *mp)
3447 {
3448 struct vnode *vp;
3449 struct bufobj *bo;
3450 static long start, incr, next;
3451 int error;
3452
3453 /* Allocate a new vnode */
3454 if ((error = getnewvnode("syncer", mp, &sync_vnodeops, &vp)) != 0) {
3455 mp->mnt_syncer = NULL;
3456 return (error);
3457 }
3458 vp->v_type = VNON;
3459 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3460 vp->v_vflag |= VV_FORCEINSMQ;
3461 error = insmntque(vp, mp);
3462 if (error != 0)
3463 panic("vfs_allocate_syncvnode: insmntque failed");
3464 vp->v_vflag &= ~VV_FORCEINSMQ;
3465 VOP_UNLOCK(vp, 0);
3466 /*
3467 * Place the vnode onto the syncer worklist. We attempt to
3468 * scatter them about on the list so that they will go off
3469 * at evenly distributed times even if all the filesystems
3470 * are mounted at once.
3471 */
3472 next += incr;
3473 if (next == 0 || next > syncer_maxdelay) {
3474 start /= 2;
3475 incr /= 2;
3476 if (start == 0) {
3477 start = syncer_maxdelay / 2;
3478 incr = syncer_maxdelay;
3479 }
3480 next = start;
3481 }
3482 bo = &vp->v_bufobj;
3483 BO_LOCK(bo);
3484 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
3485 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
3486 mtx_lock(&sync_mtx);
3487 sync_vnode_count++;
3488 mtx_unlock(&sync_mtx);
3489 BO_UNLOCK(bo);
3490 mp->mnt_syncer = vp;
3491 return (0);
3492 }
3493
3494 /*
3495 * Do a lazy sync of the filesystem.
3496 */
3497 static int
3498 sync_fsync(struct vop_fsync_args *ap)
3499 {
3500 struct vnode *syncvp = ap->a_vp;
3501 struct mount *mp = syncvp->v_mount;
3502 int error, save;
3503 struct bufobj *bo;
3504
3505 /*
3506 * We only need to do something if this is a lazy evaluation.
3507 */
3508 if (ap->a_waitfor != MNT_LAZY)
3509 return (0);
3510
3511 /*
3512 * Move ourselves to the back of the sync list.
3513 */
3514 bo = &syncvp->v_bufobj;
3515 BO_LOCK(bo);
3516 vn_syncer_add_to_worklist(bo, syncdelay);
3517 BO_UNLOCK(bo);
3518
3519 /*
3520 * Walk the list of vnodes pushing all that are dirty and
3521 * not already on the sync list.
3522 */
3523 mtx_lock(&mountlist_mtx);
3524 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
3525 mtx_unlock(&mountlist_mtx);
3526 return (0);
3527 }
3528 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
3529 vfs_unbusy(mp);
3530 return (0);
3531 }
3532 save = curthread_pflags_set(TDP_SYNCIO);
3533 vfs_msync(mp, MNT_NOWAIT);
3534 error = VFS_SYNC(mp, MNT_LAZY);
3535 curthread_pflags_restore(save);
3536 vn_finished_write(mp);
3537 vfs_unbusy(mp);
3538 return (error);
3539 }
3540
3541 /*
3542 * The syncer vnode is no referenced.
3543 */
3544 static int
3545 sync_inactive(struct vop_inactive_args *ap)
3546 {
3547
3548 vgone(ap->a_vp);
3549 return (0);
3550 }
3551
3552 /*
3553 * The syncer vnode is no longer needed and is being decommissioned.
3554 *
3555 * Modifications to the worklist must be protected by sync_mtx.
3556 */
3557 static int
3558 sync_reclaim(struct vop_reclaim_args *ap)
3559 {
3560 struct vnode *vp = ap->a_vp;
3561 struct bufobj *bo;
3562
3563 bo = &vp->v_bufobj;
3564 BO_LOCK(bo);
3565 vp->v_mount->mnt_syncer = NULL;
3566 if (bo->bo_flag & BO_ONWORKLST) {
3567 mtx_lock(&sync_mtx);
3568 LIST_REMOVE(bo, bo_synclist);
3569 syncer_worklist_len--;
3570 sync_vnode_count--;
3571 mtx_unlock(&sync_mtx);
3572 bo->bo_flag &= ~BO_ONWORKLST;
3573 }
3574 BO_UNLOCK(bo);
3575
3576 return (0);
3577 }
3578
3579 /*
3580 * Check if vnode represents a disk device
3581 */
3582 int
3583 vn_isdisk(struct vnode *vp, int *errp)
3584 {
3585 int error;
3586
3587 error = 0;
3588 dev_lock();
3589 if (vp->v_type != VCHR)
3590 error = ENOTBLK;
3591 else if (vp->v_rdev == NULL)
3592 error = ENXIO;
3593 else if (vp->v_rdev->si_devsw == NULL)
3594 error = ENXIO;
3595 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
3596 error = ENOTBLK;
3597 dev_unlock();
3598 if (errp != NULL)
3599 *errp = error;
3600 return (error == 0);
3601 }
3602
3603 /*
3604 * Common filesystem object access control check routine. Accepts a
3605 * vnode's type, "mode", uid and gid, requested access mode, credentials,
3606 * and optional call-by-reference privused argument allowing vaccess()
3607 * to indicate to the caller whether privilege was used to satisfy the
3608 * request (obsoleted). Returns 0 on success, or an errno on failure.
3609 */
3610 int
3611 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
3612 accmode_t accmode, struct ucred *cred, int *privused)
3613 {
3614 accmode_t dac_granted;
3615 accmode_t priv_granted;
3616
3617 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
3618 ("invalid bit in accmode"));
3619
3620 /*
3621 * Look for a normal, non-privileged way to access the file/directory
3622 * as requested. If it exists, go with that.
3623 */
3624
3625 if (privused != NULL)
3626 *privused = 0;
3627
3628 dac_granted = 0;
3629
3630 /* Check the owner. */
3631 if (cred->cr_uid == file_uid) {
3632 dac_granted |= VADMIN;
3633 if (file_mode & S_IXUSR)
3634 dac_granted |= VEXEC;
3635 if (file_mode & S_IRUSR)
3636 dac_granted |= VREAD;
3637 if (file_mode & S_IWUSR)
3638 dac_granted |= (VWRITE | VAPPEND);
3639
3640 if ((accmode & dac_granted) == accmode)
3641 return (0);
3642
3643 goto privcheck;
3644 }
3645
3646 /* Otherwise, check the groups (first match) */
3647 if (groupmember(file_gid, cred)) {
3648 if (file_mode & S_IXGRP)
3649 dac_granted |= VEXEC;
3650 if (file_mode & S_IRGRP)
3651 dac_granted |= VREAD;
3652 if (file_mode & S_IWGRP)
3653 dac_granted |= (VWRITE | VAPPEND);
3654
3655 if ((accmode & dac_granted) == accmode)
3656 return (0);
3657
3658 goto privcheck;
3659 }
3660
3661 /* Otherwise, check everyone else. */
3662 if (file_mode & S_IXOTH)
3663 dac_granted |= VEXEC;
3664 if (file_mode & S_IROTH)
3665 dac_granted |= VREAD;
3666 if (file_mode & S_IWOTH)
3667 dac_granted |= (VWRITE | VAPPEND);
3668 if ((accmode & dac_granted) == accmode)
3669 return (0);
3670
3671 privcheck:
3672 /*
3673 * Build a privilege mask to determine if the set of privileges
3674 * satisfies the requirements when combined with the granted mask
3675 * from above. For each privilege, if the privilege is required,
3676 * bitwise or the request type onto the priv_granted mask.
3677 */
3678 priv_granted = 0;
3679
3680 if (type == VDIR) {
3681 /*
3682 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
3683 * requests, instead of PRIV_VFS_EXEC.
3684 */
3685 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3686 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
3687 priv_granted |= VEXEC;
3688 } else {
3689 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
3690 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
3691 priv_granted |= VEXEC;
3692 }
3693
3694 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
3695 !priv_check_cred(cred, PRIV_VFS_READ, 0))
3696 priv_granted |= VREAD;
3697
3698 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
3699 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
3700 priv_granted |= (VWRITE | VAPPEND);
3701
3702 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
3703 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
3704 priv_granted |= VADMIN;
3705
3706 if ((accmode & (priv_granted | dac_granted)) == accmode) {
3707 /* XXX audit: privilege used */
3708 if (privused != NULL)
3709 *privused = 1;
3710 return (0);
3711 }
3712
3713 return ((accmode & VADMIN) ? EPERM : EACCES);
3714 }
3715
3716 /*
3717 * Credential check based on process requesting service, and per-attribute
3718 * permissions.
3719 */
3720 int
3721 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
3722 struct thread *td, accmode_t accmode)
3723 {
3724
3725 /*
3726 * Kernel-invoked always succeeds.
3727 */
3728 if (cred == NOCRED)
3729 return (0);
3730
3731 /*
3732 * Do not allow privileged processes in jail to directly manipulate
3733 * system attributes.
3734 */
3735 switch (attrnamespace) {
3736 case EXTATTR_NAMESPACE_SYSTEM:
3737 /* Potentially should be: return (EPERM); */
3738 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
3739 case EXTATTR_NAMESPACE_USER:
3740 return (VOP_ACCESS(vp, accmode, cred, td));
3741 default:
3742 return (EPERM);
3743 }
3744 }
3745
3746 #ifdef DEBUG_VFS_LOCKS
3747 /*
3748 * This only exists to supress warnings from unlocked specfs accesses. It is
3749 * no longer ok to have an unlocked VFS.
3750 */
3751 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
3752 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
3753
3754 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
3755 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
3756 "Drop into debugger on lock violation");
3757
3758 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
3759 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
3760 0, "Check for interlock across VOPs");
3761
3762 int vfs_badlock_print = 1; /* Print lock violations. */
3763 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
3764 0, "Print lock violations");
3765
3766 #ifdef KDB
3767 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
3768 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
3769 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
3770 #endif
3771
3772 static void
3773 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
3774 {
3775
3776 #ifdef KDB
3777 if (vfs_badlock_backtrace)
3778 kdb_backtrace();
3779 #endif
3780 if (vfs_badlock_print)
3781 printf("%s: %p %s\n", str, (void *)vp, msg);
3782 if (vfs_badlock_ddb)
3783 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
3784 }
3785
3786 void
3787 assert_vi_locked(struct vnode *vp, const char *str)
3788 {
3789
3790 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
3791 vfs_badlock("interlock is not locked but should be", str, vp);
3792 }
3793
3794 void
3795 assert_vi_unlocked(struct vnode *vp, const char *str)
3796 {
3797
3798 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
3799 vfs_badlock("interlock is locked but should not be", str, vp);
3800 }
3801
3802 void
3803 assert_vop_locked(struct vnode *vp, const char *str)
3804 {
3805
3806 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == 0)
3807 vfs_badlock("is not locked but should be", str, vp);
3808 }
3809
3810 void
3811 assert_vop_unlocked(struct vnode *vp, const char *str)
3812 {
3813
3814 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
3815 vfs_badlock("is locked but should not be", str, vp);
3816 }
3817
3818 void
3819 assert_vop_elocked(struct vnode *vp, const char *str)
3820 {
3821
3822 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
3823 vfs_badlock("is not exclusive locked but should be", str, vp);
3824 }
3825
3826 #if 0
3827 void
3828 assert_vop_elocked_other(struct vnode *vp, const char *str)
3829 {
3830
3831 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER)
3832 vfs_badlock("is not exclusive locked by another thread",
3833 str, vp);
3834 }
3835
3836 void
3837 assert_vop_slocked(struct vnode *vp, const char *str)
3838 {
3839
3840 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED)
3841 vfs_badlock("is not locked shared but should be", str, vp);
3842 }
3843 #endif /* 0 */
3844 #endif /* DEBUG_VFS_LOCKS */
3845
3846 void
3847 vop_rename_fail(struct vop_rename_args *ap)
3848 {
3849
3850 if (ap->a_tvp != NULL)
3851 vput(ap->a_tvp);
3852 if (ap->a_tdvp == ap->a_tvp)
3853 vrele(ap->a_tdvp);
3854 else
3855 vput(ap->a_tdvp);
3856 vrele(ap->a_fdvp);
3857 vrele(ap->a_fvp);
3858 }
3859
3860 void
3861 vop_rename_pre(void *ap)
3862 {
3863 struct vop_rename_args *a = ap;
3864
3865 #ifdef DEBUG_VFS_LOCKS
3866 if (a->a_tvp)
3867 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
3868 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
3869 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
3870 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
3871
3872 /* Check the source (from). */
3873 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
3874 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
3875 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
3876 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
3877 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
3878
3879 /* Check the target. */
3880 if (a->a_tvp)
3881 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
3882 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
3883 #endif
3884 if (a->a_tdvp != a->a_fdvp)
3885 vhold(a->a_fdvp);
3886 if (a->a_tvp != a->a_fvp)
3887 vhold(a->a_fvp);
3888 vhold(a->a_tdvp);
3889 if (a->a_tvp)
3890 vhold(a->a_tvp);
3891 }
3892
3893 void
3894 vop_strategy_pre(void *ap)
3895 {
3896 #ifdef DEBUG_VFS_LOCKS
3897 struct vop_strategy_args *a;
3898 struct buf *bp;
3899
3900 a = ap;
3901 bp = a->a_bp;
3902
3903 /*
3904 * Cluster ops lock their component buffers but not the IO container.
3905 */
3906 if ((bp->b_flags & B_CLUSTER) != 0)
3907 return;
3908
3909 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
3910 if (vfs_badlock_print)
3911 printf(
3912 "VOP_STRATEGY: bp is not locked but should be\n");
3913 if (vfs_badlock_ddb)
3914 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
3915 }
3916 #endif
3917 }
3918
3919 void
3920 vop_lookup_pre(void *ap)
3921 {
3922 #ifdef DEBUG_VFS_LOCKS
3923 struct vop_lookup_args *a;
3924 struct vnode *dvp;
3925
3926 a = ap;
3927 dvp = a->a_dvp;
3928 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3929 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3930 #endif
3931 }
3932
3933 void
3934 vop_lookup_post(void *ap, int rc)
3935 {
3936 #ifdef DEBUG_VFS_LOCKS
3937 struct vop_lookup_args *a;
3938 struct vnode *dvp;
3939 struct vnode *vp;
3940
3941 a = ap;
3942 dvp = a->a_dvp;
3943 vp = *(a->a_vpp);
3944
3945 ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP");
3946 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP");
3947
3948 if (!rc)
3949 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)");
3950 #endif
3951 }
3952
3953 void
3954 vop_lock_pre(void *ap)
3955 {
3956 #ifdef DEBUG_VFS_LOCKS
3957 struct vop_lock1_args *a = ap;
3958
3959 if ((a->a_flags & LK_INTERLOCK) == 0)
3960 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3961 else
3962 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
3963 #endif
3964 }
3965
3966 void
3967 vop_lock_post(void *ap, int rc)
3968 {
3969 #ifdef DEBUG_VFS_LOCKS
3970 struct vop_lock1_args *a = ap;
3971
3972 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
3973 if (rc == 0)
3974 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
3975 #endif
3976 }
3977
3978 void
3979 vop_unlock_pre(void *ap)
3980 {
3981 #ifdef DEBUG_VFS_LOCKS
3982 struct vop_unlock_args *a = ap;
3983
3984 if (a->a_flags & LK_INTERLOCK)
3985 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
3986 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
3987 #endif
3988 }
3989
3990 void
3991 vop_unlock_post(void *ap, int rc)
3992 {
3993 #ifdef DEBUG_VFS_LOCKS
3994 struct vop_unlock_args *a = ap;
3995
3996 if (a->a_flags & LK_INTERLOCK)
3997 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
3998 #endif
3999 }
4000
4001 void
4002 vop_create_post(void *ap, int rc)
4003 {
4004 struct vop_create_args *a = ap;
4005
4006 if (!rc)
4007 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4008 }
4009
4010 void
4011 vop_deleteextattr_post(void *ap, int rc)
4012 {
4013 struct vop_deleteextattr_args *a = ap;
4014
4015 if (!rc)
4016 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4017 }
4018
4019 void
4020 vop_link_post(void *ap, int rc)
4021 {
4022 struct vop_link_args *a = ap;
4023
4024 if (!rc) {
4025 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
4026 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
4027 }
4028 }
4029
4030 void
4031 vop_mkdir_post(void *ap, int rc)
4032 {
4033 struct vop_mkdir_args *a = ap;
4034
4035 if (!rc)
4036 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4037 }
4038
4039 void
4040 vop_mknod_post(void *ap, int rc)
4041 {
4042 struct vop_mknod_args *a = ap;
4043
4044 if (!rc)
4045 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4046 }
4047
4048 void
4049 vop_remove_post(void *ap, int rc)
4050 {
4051 struct vop_remove_args *a = ap;
4052
4053 if (!rc) {
4054 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4055 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4056 }
4057 }
4058
4059 void
4060 vop_rename_post(void *ap, int rc)
4061 {
4062 struct vop_rename_args *a = ap;
4063
4064 if (!rc) {
4065 VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE);
4066 VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE);
4067 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
4068 if (a->a_tvp)
4069 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
4070 }
4071 if (a->a_tdvp != a->a_fdvp)
4072 vdrop(a->a_fdvp);
4073 if (a->a_tvp != a->a_fvp)
4074 vdrop(a->a_fvp);
4075 vdrop(a->a_tdvp);
4076 if (a->a_tvp)
4077 vdrop(a->a_tvp);
4078 }
4079
4080 void
4081 vop_rmdir_post(void *ap, int rc)
4082 {
4083 struct vop_rmdir_args *a = ap;
4084
4085 if (!rc) {
4086 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4087 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4088 }
4089 }
4090
4091 void
4092 vop_setattr_post(void *ap, int rc)
4093 {
4094 struct vop_setattr_args *a = ap;
4095
4096 if (!rc)
4097 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4098 }
4099
4100 void
4101 vop_setextattr_post(void *ap, int rc)
4102 {
4103 struct vop_setextattr_args *a = ap;
4104
4105 if (!rc)
4106 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4107 }
4108
4109 void
4110 vop_symlink_post(void *ap, int rc)
4111 {
4112 struct vop_symlink_args *a = ap;
4113
4114 if (!rc)
4115 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4116 }
4117
4118 static struct knlist fs_knlist;
4119
4120 static void
4121 vfs_event_init(void *arg)
4122 {
4123 knlist_init_mtx(&fs_knlist, NULL);
4124 }
4125 /* XXX - correct order? */
4126 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
4127
4128 void
4129 vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused)
4130 {
4131
4132 KNOTE_UNLOCKED(&fs_knlist, event);
4133 }
4134
4135 static int filt_fsattach(struct knote *kn);
4136 static void filt_fsdetach(struct knote *kn);
4137 static int filt_fsevent(struct knote *kn, long hint);
4138
4139 struct filterops fs_filtops =
4140 { 0, filt_fsattach, filt_fsdetach, filt_fsevent };
4141
4142 static int
4143 filt_fsattach(struct knote *kn)
4144 {
4145
4146 kn->kn_flags |= EV_CLEAR;
4147 knlist_add(&fs_knlist, kn, 0);
4148 return (0);
4149 }
4150
4151 static void
4152 filt_fsdetach(struct knote *kn)
4153 {
4154
4155 knlist_remove(&fs_knlist, kn, 0);
4156 }
4157
4158 static int
4159 filt_fsevent(struct knote *kn, long hint)
4160 {
4161
4162 kn->kn_fflags |= hint;
4163 return (kn->kn_fflags != 0);
4164 }
4165
4166 static int
4167 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
4168 {
4169 struct vfsidctl vc;
4170 int error;
4171 struct mount *mp;
4172
4173 error = SYSCTL_IN(req, &vc, sizeof(vc));
4174 if (error)
4175 return (error);
4176 if (vc.vc_vers != VFS_CTL_VERS1)
4177 return (EINVAL);
4178 mp = vfs_getvfs(&vc.vc_fsid);
4179 if (mp == NULL)
4180 return (ENOENT);
4181 /* ensure that a specific sysctl goes to the right filesystem. */
4182 if (strcmp(vc.vc_fstypename, "*") != 0 &&
4183 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
4184 vfs_rel(mp);
4185 return (EINVAL);
4186 }
4187 VCTLTOREQ(&vc, req);
4188 error = VFS_SYSCTL(mp, vc.vc_op, req);
4189 vfs_rel(mp);
4190 return (error);
4191 }
4192
4193 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "",
4194 "Sysctl by fsid");
4195
4196 /*
4197 * Function to initialize a va_filerev field sensibly.
4198 * XXX: Wouldn't a random number make a lot more sense ??
4199 */
4200 u_quad_t
4201 init_va_filerev(void)
4202 {
4203 struct bintime bt;
4204
4205 getbinuptime(&bt);
4206 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
4207 }
4208
4209 static int filt_vfsread(struct knote *kn, long hint);
4210 static int filt_vfswrite(struct knote *kn, long hint);
4211 static int filt_vfsvnode(struct knote *kn, long hint);
4212 static void filt_vfsdetach(struct knote *kn);
4213 static struct filterops vfsread_filtops =
4214 { 1, NULL, filt_vfsdetach, filt_vfsread };
4215 static struct filterops vfswrite_filtops =
4216 { 1, NULL, filt_vfsdetach, filt_vfswrite };
4217 static struct filterops vfsvnode_filtops =
4218 { 1, NULL, filt_vfsdetach, filt_vfsvnode };
4219
4220 static void
4221 vfs_knllock(void *arg)
4222 {
4223 struct vnode *vp = arg;
4224
4225 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4226 }
4227
4228 static void
4229 vfs_knlunlock(void *arg)
4230 {
4231 struct vnode *vp = arg;
4232
4233 VOP_UNLOCK(vp, 0);
4234 }
4235
4236 static void
4237 vfs_knl_assert_locked(void *arg)
4238 {
4239 #ifdef DEBUG_VFS_LOCKS
4240 struct vnode *vp = arg;
4241
4242 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
4243 #endif
4244 }
4245
4246 static void
4247 vfs_knl_assert_unlocked(void *arg)
4248 {
4249 #ifdef DEBUG_VFS_LOCKS
4250 struct vnode *vp = arg;
4251
4252 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
4253 #endif
4254 }
4255
4256 int
4257 vfs_kqfilter(struct vop_kqfilter_args *ap)
4258 {
4259 struct vnode *vp = ap->a_vp;
4260 struct knote *kn = ap->a_kn;
4261 struct knlist *knl;
4262
4263 switch (kn->kn_filter) {
4264 case EVFILT_READ:
4265 kn->kn_fop = &vfsread_filtops;
4266 break;
4267 case EVFILT_WRITE:
4268 kn->kn_fop = &vfswrite_filtops;
4269 break;
4270 case EVFILT_VNODE:
4271 kn->kn_fop = &vfsvnode_filtops;
4272 break;
4273 default:
4274 return (EINVAL);
4275 }
4276
4277 kn->kn_hook = (caddr_t)vp;
4278
4279 v_addpollinfo(vp);
4280 if (vp->v_pollinfo == NULL)
4281 return (ENOMEM);
4282 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
4283 knlist_add(knl, kn, 0);
4284
4285 return (0);
4286 }
4287
4288 /*
4289 * Detach knote from vnode
4290 */
4291 static void
4292 filt_vfsdetach(struct knote *kn)
4293 {
4294 struct vnode *vp = (struct vnode *)kn->kn_hook;
4295
4296 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
4297 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
4298 }
4299
4300 /*ARGSUSED*/
4301 static int
4302 filt_vfsread(struct knote *kn, long hint)
4303 {
4304 struct vnode *vp = (struct vnode *)kn->kn_hook;
4305 struct vattr va;
4306 int res;
4307
4308 /*
4309 * filesystem is gone, so set the EOF flag and schedule
4310 * the knote for deletion.
4311 */
4312 if (hint == NOTE_REVOKE) {
4313 VI_LOCK(vp);
4314 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4315 VI_UNLOCK(vp);
4316 return (1);
4317 }
4318
4319 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
4320 return (0);
4321
4322 VI_LOCK(vp);
4323 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
4324 res = (kn->kn_data != 0);
4325 VI_UNLOCK(vp);
4326 return (res);
4327 }
4328
4329 /*ARGSUSED*/
4330 static int
4331 filt_vfswrite(struct knote *kn, long hint)
4332 {
4333 struct vnode *vp = (struct vnode *)kn->kn_hook;
4334
4335 VI_LOCK(vp);
4336
4337 /*
4338 * filesystem is gone, so set the EOF flag and schedule
4339 * the knote for deletion.
4340 */
4341 if (hint == NOTE_REVOKE)
4342 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4343
4344 kn->kn_data = 0;
4345 VI_UNLOCK(vp);
4346 return (1);
4347 }
4348
4349 static int
4350 filt_vfsvnode(struct knote *kn, long hint)
4351 {
4352 struct vnode *vp = (struct vnode *)kn->kn_hook;
4353 int res;
4354
4355 VI_LOCK(vp);
4356 if (kn->kn_sfflags & hint)
4357 kn->kn_fflags |= hint;
4358 if (hint == NOTE_REVOKE) {
4359 kn->kn_flags |= EV_EOF;
4360 VI_UNLOCK(vp);
4361 return (1);
4362 }
4363 res = (kn->kn_fflags != 0);
4364 VI_UNLOCK(vp);
4365 return (res);
4366 }
4367
4368 int
4369 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
4370 {
4371 int error;
4372
4373 if (dp->d_reclen > ap->a_uio->uio_resid)
4374 return (ENAMETOOLONG);
4375 error = uiomove(dp, dp->d_reclen, ap->a_uio);
4376 if (error) {
4377 if (ap->a_ncookies != NULL) {
4378 if (ap->a_cookies != NULL)
4379 free(ap->a_cookies, M_TEMP);
4380 ap->a_cookies = NULL;
4381 *ap->a_ncookies = 0;
4382 }
4383 return (error);
4384 }
4385 if (ap->a_ncookies == NULL)
4386 return (0);
4387
4388 KASSERT(ap->a_cookies,
4389 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
4390
4391 *ap->a_cookies = realloc(*ap->a_cookies,
4392 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
4393 (*ap->a_cookies)[*ap->a_ncookies] = off;
4394 return (0);
4395 }
4396
4397 /*
4398 * Mark for update the access time of the file if the filesystem
4399 * supports VOP_MARKATIME. This functionality is used by execve and
4400 * mmap, so we want to avoid the I/O implied by directly setting
4401 * va_atime for the sake of efficiency.
4402 */
4403 void
4404 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
4405 {
4406 struct mount *mp;
4407
4408 mp = vp->v_mount;
4409 VFS_ASSERT_GIANT(mp);
4410 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
4411 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
4412 (void)VOP_MARKATIME(vp);
4413 }
4414
4415 /*
4416 * The purpose of this routine is to remove granularity from accmode_t,
4417 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
4418 * VADMIN and VAPPEND.
4419 *
4420 * If it returns 0, the caller is supposed to continue with the usual
4421 * access checks using 'accmode' as modified by this routine. If it
4422 * returns nonzero value, the caller is supposed to return that value
4423 * as errno.
4424 *
4425 * Note that after this routine runs, accmode may be zero.
4426 */
4427 int
4428 vfs_unixify_accmode(accmode_t *accmode)
4429 {
4430 /*
4431 * There is no way to specify explicit "deny" rule using
4432 * file mode or POSIX.1e ACLs.
4433 */
4434 if (*accmode & VEXPLICIT_DENY) {
4435 *accmode = 0;
4436 return (0);
4437 }
4438
4439 /*
4440 * None of these can be translated into usual access bits.
4441 * Also, the common case for NFSv4 ACLs is to not contain
4442 * either of these bits. Caller should check for VWRITE
4443 * on the containing directory instead.
4444 */
4445 if (*accmode & (VDELETE_CHILD | VDELETE))
4446 return (EPERM);
4447
4448 if (*accmode & VADMIN_PERMS) {
4449 *accmode &= ~VADMIN_PERMS;
4450 *accmode |= VADMIN;
4451 }
4452
4453 /*
4454 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
4455 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
4456 */
4457 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
4458
4459 return (0);
4460 }
Cache object: 4a2e0a9c25ab39a59625076f7405e682
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