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("$FreeBSD$");
43
44 #include "opt_compat.h"
45 #include "opt_ddb.h"
46 #include "opt_watchdog.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/bio.h>
51 #include <sys/buf.h>
52 #include <sys/capsicum.h>
53 #include <sys/condvar.h>
54 #include <sys/conf.h>
55 #include <sys/counter.h>
56 #include <sys/dirent.h>
57 #include <sys/event.h>
58 #include <sys/eventhandler.h>
59 #include <sys/extattr.h>
60 #include <sys/file.h>
61 #include <sys/fcntl.h>
62 #include <sys/jail.h>
63 #include <sys/kdb.h>
64 #include <sys/kernel.h>
65 #include <sys/kthread.h>
66 #include <sys/lockf.h>
67 #include <sys/malloc.h>
68 #include <sys/mount.h>
69 #include <sys/namei.h>
70 #include <sys/pctrie.h>
71 #include <sys/priv.h>
72 #include <sys/reboot.h>
73 #include <sys/refcount.h>
74 #include <sys/rwlock.h>
75 #include <sys/sched.h>
76 #include <sys/sleepqueue.h>
77 #include <sys/smp.h>
78 #include <sys/stat.h>
79 #include <sys/sysctl.h>
80 #include <sys/syslog.h>
81 #include <sys/vmmeter.h>
82 #include <sys/vnode.h>
83 #include <sys/watchdog.h>
84
85 #include <machine/stdarg.h>
86
87 #include <security/mac/mac_framework.h>
88
89 #include <vm/vm.h>
90 #include <vm/vm_object.h>
91 #include <vm/vm_extern.h>
92 #include <vm/pmap.h>
93 #include <vm/vm_map.h>
94 #include <vm/vm_page.h>
95 #include <vm/vm_kern.h>
96 #include <vm/uma.h>
97
98 #ifdef DDB
99 #include <ddb/ddb.h>
100 #endif
101
102 static void delmntque(struct vnode *vp);
103 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
104 int slpflag, int slptimeo);
105 static void syncer_shutdown(void *arg, int howto);
106 static int vtryrecycle(struct vnode *vp);
107 static void v_init_counters(struct vnode *);
108 static void v_incr_usecount(struct vnode *);
109 static void v_incr_usecount_locked(struct vnode *);
110 static void v_incr_devcount(struct vnode *);
111 static void v_decr_devcount(struct vnode *);
112 static void vgonel(struct vnode *);
113 static void vfs_knllock(void *arg);
114 static void vfs_knlunlock(void *arg);
115 static void vfs_knl_assert_locked(void *arg);
116 static void vfs_knl_assert_unlocked(void *arg);
117 static void destroy_vpollinfo(struct vpollinfo *vi);
118
119 /*
120 * These fences are intended for cases where some synchronization is
121 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt
122 * and v_usecount) updates. Access to v_iflags is generally synchronized
123 * by the interlock, but we have some internal assertions that check vnode
124 * flags * without acquiring the lock. Thus, these fences are INVARIANTS-only
125 * for now.
126 */
127 #ifdef INVARIANTS
128 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq()
129 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel()
130 #else
131 #define VNODE_REFCOUNT_FENCE_ACQ()
132 #define VNODE_REFCOUNT_FENCE_REL()
133 #endif
134
135 /*
136 * Number of vnodes in existence. Increased whenever getnewvnode()
137 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
138 */
139 static unsigned long numvnodes;
140
141 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
142 "Number of vnodes in existence");
143
144 static counter_u64_t vnodes_created;
145 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
146 "Number of vnodes created by getnewvnode");
147
148 /*
149 * Conversion tables for conversion from vnode types to inode formats
150 * and back.
151 */
152 enum vtype iftovt_tab[16] = {
153 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
154 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
155 };
156 int vttoif_tab[10] = {
157 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
158 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
159 };
160
161 /*
162 * List of vnodes that are ready for recycling.
163 */
164 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
165
166 /*
167 * "Free" vnode target. Free vnodes are rarely completely free, but are
168 * just ones that are cheap to recycle. Usually they are for files which
169 * have been stat'd but not read; these usually have inode and namecache
170 * data attached to them. This target is the preferred minimum size of a
171 * sub-cache consisting mostly of such files. The system balances the size
172 * of this sub-cache with its complement to try to prevent either from
173 * thrashing while the other is relatively inactive. The targets express
174 * a preference for the best balance.
175 *
176 * "Above" this target there are 2 further targets (watermarks) related
177 * to recyling of free vnodes. In the best-operating case, the cache is
178 * exactly full, the free list has size between vlowat and vhiwat above the
179 * free target, and recycling from it and normal use maintains this state.
180 * Sometimes the free list is below vlowat or even empty, but this state
181 * is even better for immediate use provided the cache is not full.
182 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
183 * ones) to reach one of these states. The watermarks are currently hard-
184 * coded as 4% and 9% of the available space higher. These and the default
185 * of 25% for wantfreevnodes are too large if the memory size is large.
186 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
187 * whenever vnlru_proc() becomes active.
188 */
189 static u_long wantfreevnodes;
190 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW,
191 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes");
192 static u_long freevnodes;
193 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD,
194 &freevnodes, 0, "Number of \"free\" vnodes");
195
196 static counter_u64_t recycles_count;
197 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count,
198 "Number of vnodes recycled to meet vnode cache targets");
199
200 /*
201 * Various variables used for debugging the new implementation of
202 * reassignbuf().
203 * XXX these are probably of (very) limited utility now.
204 */
205 static int reassignbufcalls;
206 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
207 "Number of calls to reassignbuf");
208
209 static counter_u64_t free_owe_inact;
210 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact,
211 "Number of times free vnodes kept on active list due to VFS "
212 "owing inactivation");
213
214 /* To keep more than one thread at a time from running vfs_getnewfsid */
215 static struct mtx mntid_mtx;
216
217 /*
218 * Lock for any access to the following:
219 * vnode_free_list
220 * numvnodes
221 * freevnodes
222 */
223 static struct mtx vnode_free_list_mtx;
224
225 /* Publicly exported FS */
226 struct nfs_public nfs_pub;
227
228 static uma_zone_t buf_trie_zone;
229
230 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
231 static uma_zone_t vnode_zone;
232 static uma_zone_t vnodepoll_zone;
233
234 /*
235 * The workitem queue.
236 *
237 * It is useful to delay writes of file data and filesystem metadata
238 * for tens of seconds so that quickly created and deleted files need
239 * not waste disk bandwidth being created and removed. To realize this,
240 * we append vnodes to a "workitem" queue. When running with a soft
241 * updates implementation, most pending metadata dependencies should
242 * not wait for more than a few seconds. Thus, mounted on block devices
243 * are delayed only about a half the time that file data is delayed.
244 * Similarly, directory updates are more critical, so are only delayed
245 * about a third the time that file data is delayed. Thus, there are
246 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
247 * one each second (driven off the filesystem syncer process). The
248 * syncer_delayno variable indicates the next queue that is to be processed.
249 * Items that need to be processed soon are placed in this queue:
250 *
251 * syncer_workitem_pending[syncer_delayno]
252 *
253 * A delay of fifteen seconds is done by placing the request fifteen
254 * entries later in the queue:
255 *
256 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
257 *
258 */
259 static int syncer_delayno;
260 static long syncer_mask;
261 LIST_HEAD(synclist, bufobj);
262 static struct synclist *syncer_workitem_pending;
263 /*
264 * The sync_mtx protects:
265 * bo->bo_synclist
266 * sync_vnode_count
267 * syncer_delayno
268 * syncer_state
269 * syncer_workitem_pending
270 * syncer_worklist_len
271 * rushjob
272 */
273 static struct mtx sync_mtx;
274 static struct cv sync_wakeup;
275
276 #define SYNCER_MAXDELAY 32
277 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
278 static int syncdelay = 30; /* max time to delay syncing data */
279 static int filedelay = 30; /* time to delay syncing files */
280 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
281 "Time to delay syncing files (in seconds)");
282 static int dirdelay = 29; /* time to delay syncing directories */
283 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
284 "Time to delay syncing directories (in seconds)");
285 static int metadelay = 28; /* time to delay syncing metadata */
286 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
287 "Time to delay syncing metadata (in seconds)");
288 static int rushjob; /* number of slots to run ASAP */
289 static int stat_rush_requests; /* number of times I/O speeded up */
290 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
291 "Number of times I/O speeded up (rush requests)");
292
293 /*
294 * When shutting down the syncer, run it at four times normal speed.
295 */
296 #define SYNCER_SHUTDOWN_SPEEDUP 4
297 static int sync_vnode_count;
298 static int syncer_worklist_len;
299 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
300 syncer_state;
301
302 /* Target for maximum number of vnodes. */
303 int desiredvnodes;
304 static int gapvnodes; /* gap between wanted and desired */
305 static int vhiwat; /* enough extras after expansion */
306 static int vlowat; /* minimal extras before expansion */
307 static int vstir; /* nonzero to stir non-free vnodes */
308 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
309
310 static int
311 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS)
312 {
313 int error, old_desiredvnodes;
314
315 old_desiredvnodes = desiredvnodes;
316 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0)
317 return (error);
318 if (old_desiredvnodes != desiredvnodes) {
319 wantfreevnodes = desiredvnodes / 4;
320 /* XXX locking seems to be incomplete. */
321 vfs_hash_changesize(desiredvnodes);
322 cache_changesize(desiredvnodes);
323 }
324 return (0);
325 }
326
327 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
328 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0,
329 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes");
330 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
331 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)");
332 static int vnlru_nowhere;
333 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
334 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
335
336 static int
337 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
338 {
339 struct vnode *vp;
340 struct nameidata nd;
341 char *buf;
342 unsigned long ndflags;
343 int error;
344
345 if (req->newptr == NULL)
346 return (EINVAL);
347 if (req->newlen > PATH_MAX)
348 return (E2BIG);
349
350 buf = malloc(PATH_MAX + 1, M_TEMP, M_WAITOK);
351 error = SYSCTL_IN(req, buf, req->newlen);
352 if (error != 0)
353 goto out;
354
355 buf[req->newlen] = '\0';
356
357 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME;
358 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread);
359 if ((error = namei(&nd)) != 0)
360 goto out;
361 vp = nd.ni_vp;
362
363 if ((vp->v_iflag & VI_DOOMED) != 0) {
364 /*
365 * This vnode is being recycled. Return != 0 to let the caller
366 * know that the sysctl had no effect. Return EAGAIN because a
367 * subsequent call will likely succeed (since namei will create
368 * a new vnode if necessary)
369 */
370 error = EAGAIN;
371 goto putvnode;
372 }
373
374 counter_u64_add(recycles_count, 1);
375 vgone(vp);
376 putvnode:
377 NDFREE(&nd, 0);
378 out:
379 free(buf, M_TEMP);
380 return (error);
381 }
382
383 static int
384 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)
385 {
386 struct thread *td = curthread;
387 struct vnode *vp;
388 struct file *fp;
389 cap_rights_t rights;
390 int error;
391 int fd;
392
393 if (req->newptr == NULL)
394 return (EBADF);
395
396 error = sysctl_handle_int(oidp, &fd, 0, req);
397 if (error != 0)
398 return (error);
399 cap_rights_init(&rights, CAP_FCNTL);
400 error = getvnode(curthread, fd, &rights, &fp);
401 if (error != 0)
402 return (error);
403 vp = fp->f_vnode;
404
405 error = vn_lock(vp, LK_EXCLUSIVE);
406 if (error != 0)
407 goto drop;
408
409 counter_u64_add(recycles_count, 1);
410 vgone(vp);
411 VOP_UNLOCK(vp, 0);
412 drop:
413 fdrop(fp, td);
414 return (error);
415 }
416
417 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
418 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
419 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
420 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode,
421 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
422 sysctl_ftry_reclaim_vnode, "I",
423 "Try to reclaim a vnode by its file descriptor");
424
425 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
426 static int vnsz2log;
427
428 /*
429 * Support for the bufobj clean & dirty pctrie.
430 */
431 static void *
432 buf_trie_alloc(struct pctrie *ptree)
433 {
434
435 return uma_zalloc(buf_trie_zone, M_NOWAIT);
436 }
437
438 static void
439 buf_trie_free(struct pctrie *ptree, void *node)
440 {
441
442 uma_zfree(buf_trie_zone, node);
443 }
444 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
445
446 /*
447 * Initialize the vnode management data structures.
448 *
449 * Reevaluate the following cap on the number of vnodes after the physical
450 * memory size exceeds 512GB. In the limit, as the physical memory size
451 * grows, the ratio of the memory size in KB to vnodes approaches 64:1.
452 */
453 #ifndef MAXVNODES_MAX
454 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */
455 #endif
456
457 /*
458 * Initialize a vnode as it first enters the zone.
459 */
460 static int
461 vnode_init(void *mem, int size, int flags)
462 {
463 struct vnode *vp;
464 struct bufobj *bo;
465
466 vp = mem;
467 bzero(vp, size);
468 /*
469 * Setup locks.
470 */
471 vp->v_vnlock = &vp->v_lock;
472 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
473 /*
474 * By default, don't allow shared locks unless filesystems opt-in.
475 */
476 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
477 LK_NOSHARE | LK_IS_VNODE);
478 /*
479 * Initialize bufobj.
480 */
481 bo = &vp->v_bufobj;
482 bo->__bo_vnode = vp;
483 rw_init(BO_LOCKPTR(bo), "bufobj interlock");
484 bo->bo_private = vp;
485 TAILQ_INIT(&bo->bo_clean.bv_hd);
486 TAILQ_INIT(&bo->bo_dirty.bv_hd);
487 /*
488 * Initialize namecache.
489 */
490 LIST_INIT(&vp->v_cache_src);
491 TAILQ_INIT(&vp->v_cache_dst);
492 /*
493 * Initialize rangelocks.
494 */
495 rangelock_init(&vp->v_rl);
496 return (0);
497 }
498
499 /*
500 * Free a vnode when it is cleared from the zone.
501 */
502 static void
503 vnode_fini(void *mem, int size)
504 {
505 struct vnode *vp;
506 struct bufobj *bo;
507
508 vp = mem;
509 rangelock_destroy(&vp->v_rl);
510 lockdestroy(vp->v_vnlock);
511 mtx_destroy(&vp->v_interlock);
512 bo = &vp->v_bufobj;
513 rw_destroy(BO_LOCKPTR(bo));
514 }
515
516 /*
517 * Provide the size of NFS nclnode and NFS fh for calculation of the
518 * vnode memory consumption. The size is specified directly to
519 * eliminate dependency on NFS-private header.
520 *
521 * Other filesystems may use bigger or smaller (like UFS and ZFS)
522 * private inode data, but the NFS-based estimation is ample enough.
523 * Still, we care about differences in the size between 64- and 32-bit
524 * platforms.
525 *
526 * Namecache structure size is heuristically
527 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
528 */
529 #ifdef _LP64
530 #define NFS_NCLNODE_SZ (528 + 64)
531 #define NC_SZ 148
532 #else
533 #define NFS_NCLNODE_SZ (360 + 32)
534 #define NC_SZ 92
535 #endif
536
537 static void
538 vntblinit(void *dummy __unused)
539 {
540 u_int i;
541 int physvnodes, virtvnodes;
542
543 /*
544 * Desiredvnodes is a function of the physical memory size and the
545 * kernel's heap size. Generally speaking, it scales with the
546 * physical memory size. The ratio of desiredvnodes to the physical
547 * memory size is 1:16 until desiredvnodes exceeds 98,304.
548 * Thereafter, the
549 * marginal ratio of desiredvnodes to the physical memory size is
550 * 1:64. However, desiredvnodes is limited by the kernel's heap
551 * size. The memory required by desiredvnodes vnodes and vm objects
552 * must not exceed 1/10th of the kernel's heap size.
553 */
554 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
555 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
556 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
557 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
558 desiredvnodes = min(physvnodes, virtvnodes);
559 if (desiredvnodes > MAXVNODES_MAX) {
560 if (bootverbose)
561 printf("Reducing kern.maxvnodes %d -> %d\n",
562 desiredvnodes, MAXVNODES_MAX);
563 desiredvnodes = MAXVNODES_MAX;
564 }
565 wantfreevnodes = desiredvnodes / 4;
566 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
567 TAILQ_INIT(&vnode_free_list);
568 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
569 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
570 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0);
571 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
572 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
573 /*
574 * Preallocate enough nodes to support one-per buf so that
575 * we can not fail an insert. reassignbuf() callers can not
576 * tolerate the insertion failure.
577 */
578 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
579 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
580 UMA_ZONE_NOFREE | UMA_ZONE_VM);
581 uma_prealloc(buf_trie_zone, nbuf);
582
583 vnodes_created = counter_u64_alloc(M_WAITOK);
584 recycles_count = counter_u64_alloc(M_WAITOK);
585 free_owe_inact = counter_u64_alloc(M_WAITOK);
586
587 /*
588 * Initialize the filesystem syncer.
589 */
590 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
591 &syncer_mask);
592 syncer_maxdelay = syncer_mask + 1;
593 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
594 cv_init(&sync_wakeup, "syncer");
595 for (i = 1; i <= sizeof(struct vnode); i <<= 1)
596 vnsz2log++;
597 vnsz2log--;
598 }
599 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
600
601
602 /*
603 * Mark a mount point as busy. Used to synchronize access and to delay
604 * unmounting. Eventually, mountlist_mtx is not released on failure.
605 *
606 * vfs_busy() is a custom lock, it can block the caller.
607 * vfs_busy() only sleeps if the unmount is active on the mount point.
608 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
609 * vnode belonging to mp.
610 *
611 * Lookup uses vfs_busy() to traverse mount points.
612 * root fs var fs
613 * / vnode lock A / vnode lock (/var) D
614 * /var vnode lock B /log vnode lock(/var/log) E
615 * vfs_busy lock C vfs_busy lock F
616 *
617 * Within each file system, the lock order is C->A->B and F->D->E.
618 *
619 * When traversing across mounts, the system follows that lock order:
620 *
621 * C->A->B
622 * |
623 * +->F->D->E
624 *
625 * The lookup() process for namei("/var") illustrates the process:
626 * VOP_LOOKUP() obtains B while A is held
627 * vfs_busy() obtains a shared lock on F while A and B are held
628 * vput() releases lock on B
629 * vput() releases lock on A
630 * VFS_ROOT() obtains lock on D while shared lock on F is held
631 * vfs_unbusy() releases shared lock on F
632 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
633 * Attempt to lock A (instead of vp_crossmp) while D is held would
634 * violate the global order, causing deadlocks.
635 *
636 * dounmount() locks B while F is drained.
637 */
638 int
639 vfs_busy(struct mount *mp, int flags)
640 {
641
642 MPASS((flags & ~MBF_MASK) == 0);
643 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
644
645 MNT_ILOCK(mp);
646 MNT_REF(mp);
647 /*
648 * If mount point is currently being unmounted, sleep until the
649 * mount point fate is decided. If thread doing the unmounting fails,
650 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
651 * that this mount point has survived the unmount attempt and vfs_busy
652 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
653 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
654 * about to be really destroyed. vfs_busy needs to release its
655 * reference on the mount point in this case and return with ENOENT,
656 * telling the caller that mount mount it tried to busy is no longer
657 * valid.
658 */
659 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
660 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
661 MNT_REL(mp);
662 MNT_IUNLOCK(mp);
663 CTR1(KTR_VFS, "%s: failed busying before sleeping",
664 __func__);
665 return (ENOENT);
666 }
667 if (flags & MBF_MNTLSTLOCK)
668 mtx_unlock(&mountlist_mtx);
669 mp->mnt_kern_flag |= MNTK_MWAIT;
670 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
671 if (flags & MBF_MNTLSTLOCK)
672 mtx_lock(&mountlist_mtx);
673 MNT_ILOCK(mp);
674 }
675 if (flags & MBF_MNTLSTLOCK)
676 mtx_unlock(&mountlist_mtx);
677 mp->mnt_lockref++;
678 MNT_IUNLOCK(mp);
679 return (0);
680 }
681
682 /*
683 * Free a busy filesystem.
684 */
685 void
686 vfs_unbusy(struct mount *mp)
687 {
688
689 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
690 MNT_ILOCK(mp);
691 MNT_REL(mp);
692 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
693 mp->mnt_lockref--;
694 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
695 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
696 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
697 mp->mnt_kern_flag &= ~MNTK_DRAINING;
698 wakeup(&mp->mnt_lockref);
699 }
700 MNT_IUNLOCK(mp);
701 }
702
703 /*
704 * Lookup a mount point by filesystem identifier.
705 */
706 struct mount *
707 vfs_getvfs(fsid_t *fsid)
708 {
709 struct mount *mp;
710
711 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
712 mtx_lock(&mountlist_mtx);
713 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
714 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
715 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
716 vfs_ref(mp);
717 mtx_unlock(&mountlist_mtx);
718 return (mp);
719 }
720 }
721 mtx_unlock(&mountlist_mtx);
722 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
723 return ((struct mount *) 0);
724 }
725
726 /*
727 * Lookup a mount point by filesystem identifier, busying it before
728 * returning.
729 *
730 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
731 * cache for popular filesystem identifiers. The cache is lockess, using
732 * the fact that struct mount's are never freed. In worst case we may
733 * get pointer to unmounted or even different filesystem, so we have to
734 * check what we got, and go slow way if so.
735 */
736 struct mount *
737 vfs_busyfs(fsid_t *fsid)
738 {
739 #define FSID_CACHE_SIZE 256
740 typedef struct mount * volatile vmp_t;
741 static vmp_t cache[FSID_CACHE_SIZE];
742 struct mount *mp;
743 int error;
744 uint32_t hash;
745
746 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
747 hash = fsid->val[0] ^ fsid->val[1];
748 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
749 mp = cache[hash];
750 if (mp == NULL ||
751 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] ||
752 mp->mnt_stat.f_fsid.val[1] != fsid->val[1])
753 goto slow;
754 if (vfs_busy(mp, 0) != 0) {
755 cache[hash] = NULL;
756 goto slow;
757 }
758 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
759 mp->mnt_stat.f_fsid.val[1] == fsid->val[1])
760 return (mp);
761 else
762 vfs_unbusy(mp);
763
764 slow:
765 mtx_lock(&mountlist_mtx);
766 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
767 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
768 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
769 error = vfs_busy(mp, MBF_MNTLSTLOCK);
770 if (error) {
771 cache[hash] = NULL;
772 mtx_unlock(&mountlist_mtx);
773 return (NULL);
774 }
775 cache[hash] = mp;
776 return (mp);
777 }
778 }
779 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
780 mtx_unlock(&mountlist_mtx);
781 return ((struct mount *) 0);
782 }
783
784 /*
785 * Check if a user can access privileged mount options.
786 */
787 int
788 vfs_suser(struct mount *mp, struct thread *td)
789 {
790 int error;
791
792 /*
793 * If the thread is jailed, but this is not a jail-friendly file
794 * system, deny immediately.
795 */
796 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
797 return (EPERM);
798
799 /*
800 * If the file system was mounted outside the jail of the calling
801 * thread, deny immediately.
802 */
803 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
804 return (EPERM);
805
806 /*
807 * If file system supports delegated administration, we don't check
808 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
809 * by the file system itself.
810 * If this is not the user that did original mount, we check for
811 * the PRIV_VFS_MOUNT_OWNER privilege.
812 */
813 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
814 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
815 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
816 return (error);
817 }
818 return (0);
819 }
820
821 /*
822 * Get a new unique fsid. Try to make its val[0] unique, since this value
823 * will be used to create fake device numbers for stat(). Also try (but
824 * not so hard) make its val[0] unique mod 2^16, since some emulators only
825 * support 16-bit device numbers. We end up with unique val[0]'s for the
826 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
827 *
828 * Keep in mind that several mounts may be running in parallel. Starting
829 * the search one past where the previous search terminated is both a
830 * micro-optimization and a defense against returning the same fsid to
831 * different mounts.
832 */
833 void
834 vfs_getnewfsid(struct mount *mp)
835 {
836 static uint16_t mntid_base;
837 struct mount *nmp;
838 fsid_t tfsid;
839 int mtype;
840
841 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
842 mtx_lock(&mntid_mtx);
843 mtype = mp->mnt_vfc->vfc_typenum;
844 tfsid.val[1] = mtype;
845 mtype = (mtype & 0xFF) << 24;
846 for (;;) {
847 tfsid.val[0] = makedev(255,
848 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
849 mntid_base++;
850 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
851 break;
852 vfs_rel(nmp);
853 }
854 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
855 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
856 mtx_unlock(&mntid_mtx);
857 }
858
859 /*
860 * Knob to control the precision of file timestamps:
861 *
862 * 0 = seconds only; nanoseconds zeroed.
863 * 1 = seconds and nanoseconds, accurate within 1/HZ.
864 * 2 = seconds and nanoseconds, truncated to microseconds.
865 * >=3 = seconds and nanoseconds, maximum precision.
866 */
867 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
868
869 static int timestamp_precision = TSP_USEC;
870 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
871 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
872 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, "
873 "3+: sec + ns (max. precision))");
874
875 /*
876 * Get a current timestamp.
877 */
878 void
879 vfs_timestamp(struct timespec *tsp)
880 {
881 struct timeval tv;
882
883 switch (timestamp_precision) {
884 case TSP_SEC:
885 tsp->tv_sec = time_second;
886 tsp->tv_nsec = 0;
887 break;
888 case TSP_HZ:
889 getnanotime(tsp);
890 break;
891 case TSP_USEC:
892 microtime(&tv);
893 TIMEVAL_TO_TIMESPEC(&tv, tsp);
894 break;
895 case TSP_NSEC:
896 default:
897 nanotime(tsp);
898 break;
899 }
900 }
901
902 /*
903 * Set vnode attributes to VNOVAL
904 */
905 void
906 vattr_null(struct vattr *vap)
907 {
908
909 vap->va_type = VNON;
910 vap->va_size = VNOVAL;
911 vap->va_bytes = VNOVAL;
912 vap->va_mode = VNOVAL;
913 vap->va_nlink = VNOVAL;
914 vap->va_uid = VNOVAL;
915 vap->va_gid = VNOVAL;
916 vap->va_fsid = VNOVAL;
917 vap->va_fileid = VNOVAL;
918 vap->va_blocksize = VNOVAL;
919 vap->va_rdev = VNOVAL;
920 vap->va_atime.tv_sec = VNOVAL;
921 vap->va_atime.tv_nsec = VNOVAL;
922 vap->va_mtime.tv_sec = VNOVAL;
923 vap->va_mtime.tv_nsec = VNOVAL;
924 vap->va_ctime.tv_sec = VNOVAL;
925 vap->va_ctime.tv_nsec = VNOVAL;
926 vap->va_birthtime.tv_sec = VNOVAL;
927 vap->va_birthtime.tv_nsec = VNOVAL;
928 vap->va_flags = VNOVAL;
929 vap->va_gen = VNOVAL;
930 vap->va_vaflags = 0;
931 }
932
933 /*
934 * This routine is called when we have too many vnodes. It attempts
935 * to free <count> vnodes and will potentially free vnodes that still
936 * have VM backing store (VM backing store is typically the cause
937 * of a vnode blowout so we want to do this). Therefore, this operation
938 * is not considered cheap.
939 *
940 * A number of conditions may prevent a vnode from being reclaimed.
941 * the buffer cache may have references on the vnode, a directory
942 * vnode may still have references due to the namei cache representing
943 * underlying files, or the vnode may be in active use. It is not
944 * desirable to reuse such vnodes. These conditions may cause the
945 * number of vnodes to reach some minimum value regardless of what
946 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
947 */
948 static int
949 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger)
950 {
951 struct vnode *vp;
952 int count, done, target;
953
954 done = 0;
955 vn_start_write(NULL, &mp, V_WAIT);
956 MNT_ILOCK(mp);
957 count = mp->mnt_nvnodelistsize;
958 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1);
959 target = target / 10 + 1;
960 while (count != 0 && done < target) {
961 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
962 while (vp != NULL && vp->v_type == VMARKER)
963 vp = TAILQ_NEXT(vp, v_nmntvnodes);
964 if (vp == NULL)
965 break;
966 /*
967 * XXX LRU is completely broken for non-free vnodes. First
968 * by calling here in mountpoint order, then by moving
969 * unselected vnodes to the end here, and most grossly by
970 * removing the vlruvp() function that was supposed to
971 * maintain the order. (This function was born broken
972 * since syncer problems prevented it doing anything.) The
973 * order is closer to LRC (C = Created).
974 *
975 * LRU reclaiming of vnodes seems to have last worked in
976 * FreeBSD-3 where LRU wasn't mentioned under any spelling.
977 * Then there was no hold count, and inactive vnodes were
978 * simply put on the free list in LRU order. The separate
979 * lists also break LRU. We prefer to reclaim from the
980 * free list for technical reasons. This tends to thrash
981 * the free list to keep very unrecently used held vnodes.
982 * The problem is mitigated by keeping the free list large.
983 */
984 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
985 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
986 --count;
987 if (!VI_TRYLOCK(vp))
988 goto next_iter;
989 /*
990 * If it's been deconstructed already, it's still
991 * referenced, or it exceeds the trigger, skip it.
992 * Also skip free vnodes. We are trying to make space
993 * to expand the free list, not reduce it.
994 */
995 if (vp->v_usecount ||
996 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
997 ((vp->v_iflag & VI_FREE) != 0) ||
998 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
999 vp->v_object->resident_page_count > trigger)) {
1000 VI_UNLOCK(vp);
1001 goto next_iter;
1002 }
1003 MNT_IUNLOCK(mp);
1004 vholdl(vp);
1005 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
1006 vdrop(vp);
1007 goto next_iter_mntunlocked;
1008 }
1009 VI_LOCK(vp);
1010 /*
1011 * v_usecount may have been bumped after VOP_LOCK() dropped
1012 * the vnode interlock and before it was locked again.
1013 *
1014 * It is not necessary to recheck VI_DOOMED because it can
1015 * only be set by another thread that holds both the vnode
1016 * lock and vnode interlock. If another thread has the
1017 * vnode lock before we get to VOP_LOCK() and obtains the
1018 * vnode interlock after VOP_LOCK() drops the vnode
1019 * interlock, the other thread will be unable to drop the
1020 * vnode lock before our VOP_LOCK() call fails.
1021 */
1022 if (vp->v_usecount ||
1023 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1024 (vp->v_iflag & VI_FREE) != 0 ||
1025 (vp->v_object != NULL &&
1026 vp->v_object->resident_page_count > trigger)) {
1027 VOP_UNLOCK(vp, LK_INTERLOCK);
1028 vdrop(vp);
1029 goto next_iter_mntunlocked;
1030 }
1031 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
1032 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
1033 counter_u64_add(recycles_count, 1);
1034 vgonel(vp);
1035 VOP_UNLOCK(vp, 0);
1036 vdropl(vp);
1037 done++;
1038 next_iter_mntunlocked:
1039 if (!should_yield())
1040 goto relock_mnt;
1041 goto yield;
1042 next_iter:
1043 if (!should_yield())
1044 continue;
1045 MNT_IUNLOCK(mp);
1046 yield:
1047 kern_yield(PRI_USER);
1048 relock_mnt:
1049 MNT_ILOCK(mp);
1050 }
1051 MNT_IUNLOCK(mp);
1052 vn_finished_write(mp);
1053 return done;
1054 }
1055
1056 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */
1057 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free,
1058 0,
1059 "limit on vnode free requests per call to the vnlru_free routine");
1060
1061 /*
1062 * Attempt to reduce the free list by the requested amount.
1063 */
1064 static void
1065 vnlru_free_locked(int count, struct vfsops *mnt_op)
1066 {
1067 struct vnode *vp;
1068 struct mount *mp;
1069
1070 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
1071 if (count > max_vnlru_free)
1072 count = max_vnlru_free;
1073 for (; count > 0; count--) {
1074 vp = TAILQ_FIRST(&vnode_free_list);
1075 /*
1076 * The list can be modified while the free_list_mtx
1077 * has been dropped and vp could be NULL here.
1078 */
1079 if (!vp)
1080 break;
1081 VNASSERT(vp->v_op != NULL, vp,
1082 ("vnlru_free: vnode already reclaimed."));
1083 KASSERT((vp->v_iflag & VI_FREE) != 0,
1084 ("Removing vnode not on freelist"));
1085 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1086 ("Mangling active vnode"));
1087 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
1088
1089 /*
1090 * Don't recycle if our vnode is from different type
1091 * of mount point. Note that mp is type-safe, the
1092 * check does not reach unmapped address even if
1093 * vnode is reclaimed.
1094 * Don't recycle if we can't get the interlock without
1095 * blocking.
1096 */
1097 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL &&
1098 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) {
1099 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
1100 continue;
1101 }
1102 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0,
1103 vp, ("vp inconsistent on freelist"));
1104
1105 /*
1106 * The clear of VI_FREE prevents activation of the
1107 * vnode. There is no sense in putting the vnode on
1108 * the mount point active list, only to remove it
1109 * later during recycling. Inline the relevant part
1110 * of vholdl(), to avoid triggering assertions or
1111 * activating.
1112 */
1113 freevnodes--;
1114 vp->v_iflag &= ~VI_FREE;
1115 VNODE_REFCOUNT_FENCE_REL();
1116 refcount_acquire(&vp->v_holdcnt);
1117
1118 mtx_unlock(&vnode_free_list_mtx);
1119 VI_UNLOCK(vp);
1120 vtryrecycle(vp);
1121 /*
1122 * If the recycled succeeded this vdrop will actually free
1123 * the vnode. If not it will simply place it back on
1124 * the free list.
1125 */
1126 vdrop(vp);
1127 mtx_lock(&vnode_free_list_mtx);
1128 }
1129 }
1130
1131 void
1132 vnlru_free(int count, struct vfsops *mnt_op)
1133 {
1134
1135 mtx_lock(&vnode_free_list_mtx);
1136 vnlru_free_locked(count, mnt_op);
1137 mtx_unlock(&vnode_free_list_mtx);
1138 }
1139
1140
1141 /* XXX some names and initialization are bad for limits and watermarks. */
1142 static int
1143 vspace(void)
1144 {
1145 int space;
1146
1147 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1148 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1149 vlowat = vhiwat / 2;
1150 if (numvnodes > desiredvnodes)
1151 return (0);
1152 space = desiredvnodes - numvnodes;
1153 if (freevnodes > wantfreevnodes)
1154 space += freevnodes - wantfreevnodes;
1155 return (space);
1156 }
1157
1158 /*
1159 * Attempt to recycle vnodes in a context that is always safe to block.
1160 * Calling vlrurecycle() from the bowels of filesystem code has some
1161 * interesting deadlock problems.
1162 */
1163 static struct proc *vnlruproc;
1164 static int vnlruproc_sig;
1165
1166 static void
1167 vnlru_proc(void)
1168 {
1169 struct mount *mp, *nmp;
1170 unsigned long ofreevnodes, onumvnodes;
1171 int done, force, reclaim_nc_src, trigger, usevnodes, vsp;
1172
1173 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1174 SHUTDOWN_PRI_FIRST);
1175
1176 force = 0;
1177 for (;;) {
1178 kproc_suspend_check(vnlruproc);
1179 mtx_lock(&vnode_free_list_mtx);
1180 /*
1181 * If numvnodes is too large (due to desiredvnodes being
1182 * adjusted using its sysctl, or emergency growth), first
1183 * try to reduce it by discarding from the free list.
1184 */
1185 if (numvnodes > desiredvnodes && freevnodes > 0)
1186 vnlru_free_locked(ulmin(numvnodes - desiredvnodes,
1187 freevnodes), NULL);
1188 /*
1189 * Sleep if the vnode cache is in a good state. This is
1190 * when it is not over-full and has space for about a 4%
1191 * or 9% expansion (by growing its size or inexcessively
1192 * reducing its free list). Otherwise, try to reclaim
1193 * space for a 10% expansion.
1194 */
1195 if (vstir && force == 0) {
1196 force = 1;
1197 vstir = 0;
1198 }
1199 vsp = vspace();
1200 if (vsp >= vlowat && force == 0) {
1201 vnlruproc_sig = 0;
1202 wakeup(&vnlruproc_sig);
1203 msleep(vnlruproc, &vnode_free_list_mtx,
1204 PVFS|PDROP, "vlruwt", hz);
1205 continue;
1206 }
1207 mtx_unlock(&vnode_free_list_mtx);
1208 done = 0;
1209 ofreevnodes = freevnodes;
1210 onumvnodes = numvnodes;
1211 /*
1212 * Calculate parameters for recycling. These are the same
1213 * throughout the loop to give some semblance of fairness.
1214 * The trigger point is to avoid recycling vnodes with lots
1215 * of resident pages. We aren't trying to free memory; we
1216 * are trying to recycle or at least free vnodes.
1217 */
1218 if (numvnodes <= desiredvnodes)
1219 usevnodes = numvnodes - freevnodes;
1220 else
1221 usevnodes = numvnodes;
1222 if (usevnodes <= 0)
1223 usevnodes = 1;
1224 /*
1225 * The trigger value is is chosen to give a conservatively
1226 * large value to ensure that it alone doesn't prevent
1227 * making progress. The value can easily be so large that
1228 * it is effectively infinite in some congested and
1229 * misconfigured cases, and this is necessary. Normally
1230 * it is about 8 to 100 (pages), which is quite large.
1231 */
1232 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1233 if (force < 2)
1234 trigger = vsmalltrigger;
1235 reclaim_nc_src = force >= 3;
1236 mtx_lock(&mountlist_mtx);
1237 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1238 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
1239 nmp = TAILQ_NEXT(mp, mnt_list);
1240 continue;
1241 }
1242 done += vlrureclaim(mp, reclaim_nc_src, trigger);
1243 mtx_lock(&mountlist_mtx);
1244 nmp = TAILQ_NEXT(mp, mnt_list);
1245 vfs_unbusy(mp);
1246 }
1247 mtx_unlock(&mountlist_mtx);
1248 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes)
1249 uma_reclaim();
1250 if (done == 0) {
1251 if (force == 0 || force == 1) {
1252 force = 2;
1253 continue;
1254 }
1255 if (force == 2) {
1256 force = 3;
1257 continue;
1258 }
1259 force = 0;
1260 vnlru_nowhere++;
1261 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1262 } else
1263 kern_yield(PRI_USER);
1264 /*
1265 * After becoming active to expand above low water, keep
1266 * active until above high water.
1267 */
1268 vsp = vspace();
1269 force = vsp < vhiwat;
1270 }
1271 }
1272
1273 static struct kproc_desc vnlru_kp = {
1274 "vnlru",
1275 vnlru_proc,
1276 &vnlruproc
1277 };
1278 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1279 &vnlru_kp);
1280
1281 /*
1282 * Routines having to do with the management of the vnode table.
1283 */
1284
1285 /*
1286 * Try to recycle a freed vnode. We abort if anyone picks up a reference
1287 * before we actually vgone(). This function must be called with the vnode
1288 * held to prevent the vnode from being returned to the free list midway
1289 * through vgone().
1290 */
1291 static int
1292 vtryrecycle(struct vnode *vp)
1293 {
1294 struct mount *vnmp;
1295
1296 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1297 VNASSERT(vp->v_holdcnt, vp,
1298 ("vtryrecycle: Recycling vp %p without a reference.", vp));
1299 /*
1300 * This vnode may found and locked via some other list, if so we
1301 * can't recycle it yet.
1302 */
1303 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1304 CTR2(KTR_VFS,
1305 "%s: impossible to recycle, vp %p lock is already held",
1306 __func__, vp);
1307 return (EWOULDBLOCK);
1308 }
1309 /*
1310 * Don't recycle if its filesystem is being suspended.
1311 */
1312 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1313 VOP_UNLOCK(vp, 0);
1314 CTR2(KTR_VFS,
1315 "%s: impossible to recycle, cannot start the write for %p",
1316 __func__, vp);
1317 return (EBUSY);
1318 }
1319 /*
1320 * If we got this far, we need to acquire the interlock and see if
1321 * anyone picked up this vnode from another list. If not, we will
1322 * mark it with DOOMED via vgonel() so that anyone who does find it
1323 * will skip over it.
1324 */
1325 VI_LOCK(vp);
1326 if (vp->v_usecount) {
1327 VOP_UNLOCK(vp, LK_INTERLOCK);
1328 vn_finished_write(vnmp);
1329 CTR2(KTR_VFS,
1330 "%s: impossible to recycle, %p is already referenced",
1331 __func__, vp);
1332 return (EBUSY);
1333 }
1334 if ((vp->v_iflag & VI_DOOMED) == 0) {
1335 counter_u64_add(recycles_count, 1);
1336 vgonel(vp);
1337 }
1338 VOP_UNLOCK(vp, LK_INTERLOCK);
1339 vn_finished_write(vnmp);
1340 return (0);
1341 }
1342
1343 static void
1344 vcheckspace(void)
1345 {
1346 int vsp;
1347
1348 vsp = vspace();
1349 if (vsp < vlowat && vnlruproc_sig == 0) {
1350 vnlruproc_sig = 1;
1351 wakeup(vnlruproc);
1352 }
1353 }
1354
1355 /*
1356 * Wait if necessary for space for a new vnode.
1357 */
1358 static int
1359 getnewvnode_wait(int suspended)
1360 {
1361
1362 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
1363 if (numvnodes >= desiredvnodes) {
1364 if (suspended) {
1365 /*
1366 * The file system is being suspended. We cannot
1367 * risk a deadlock here, so allow allocation of
1368 * another vnode even if this would give too many.
1369 */
1370 return (0);
1371 }
1372 if (vnlruproc_sig == 0) {
1373 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
1374 wakeup(vnlruproc);
1375 }
1376 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
1377 "vlruwk", hz);
1378 }
1379 /* Post-adjust like the pre-adjust in getnewvnode(). */
1380 if (numvnodes + 1 > desiredvnodes && freevnodes > 1)
1381 vnlru_free_locked(1, NULL);
1382 return (numvnodes >= desiredvnodes ? ENFILE : 0);
1383 }
1384
1385 /*
1386 * This hack is fragile, and probably not needed any more now that the
1387 * watermark handling works.
1388 */
1389 void
1390 getnewvnode_reserve(u_int count)
1391 {
1392 struct thread *td;
1393
1394 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */
1395 /* XXX no longer so quick, but this part is not racy. */
1396 mtx_lock(&vnode_free_list_mtx);
1397 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes)
1398 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes,
1399 freevnodes - wantfreevnodes), NULL);
1400 mtx_unlock(&vnode_free_list_mtx);
1401
1402 td = curthread;
1403 /* First try to be quick and racy. */
1404 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) {
1405 td->td_vp_reserv += count;
1406 vcheckspace(); /* XXX no longer so quick, but more racy */
1407 return;
1408 } else
1409 atomic_subtract_long(&numvnodes, count);
1410
1411 mtx_lock(&vnode_free_list_mtx);
1412 while (count > 0) {
1413 if (getnewvnode_wait(0) == 0) {
1414 count--;
1415 td->td_vp_reserv++;
1416 atomic_add_long(&numvnodes, 1);
1417 }
1418 }
1419 vcheckspace();
1420 mtx_unlock(&vnode_free_list_mtx);
1421 }
1422
1423 /*
1424 * This hack is fragile, especially if desiredvnodes or wantvnodes are
1425 * misconfgured or changed significantly. Reducing desiredvnodes below
1426 * the reserved amount should cause bizarre behaviour like reducing it
1427 * below the number of active vnodes -- the system will try to reduce
1428 * numvnodes to match, but should fail, so the subtraction below should
1429 * not overflow.
1430 */
1431 void
1432 getnewvnode_drop_reserve(void)
1433 {
1434 struct thread *td;
1435
1436 td = curthread;
1437 atomic_subtract_long(&numvnodes, td->td_vp_reserv);
1438 td->td_vp_reserv = 0;
1439 }
1440
1441 /*
1442 * Return the next vnode from the free list.
1443 */
1444 int
1445 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
1446 struct vnode **vpp)
1447 {
1448 struct vnode *vp;
1449 struct thread *td;
1450 struct lock_object *lo;
1451 static int cyclecount;
1452 int error;
1453
1454 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
1455 vp = NULL;
1456 td = curthread;
1457 if (td->td_vp_reserv > 0) {
1458 td->td_vp_reserv -= 1;
1459 goto alloc;
1460 }
1461 mtx_lock(&vnode_free_list_mtx);
1462 if (numvnodes < desiredvnodes)
1463 cyclecount = 0;
1464 else if (cyclecount++ >= freevnodes) {
1465 cyclecount = 0;
1466 vstir = 1;
1467 }
1468 /*
1469 * Grow the vnode cache if it will not be above its target max
1470 * after growing. Otherwise, if the free list is nonempty, try
1471 * to reclaim 1 item from it before growing the cache (possibly
1472 * above its target max if the reclamation failed or is delayed).
1473 * Otherwise, wait for some space. In all cases, schedule
1474 * vnlru_proc() if we are getting short of space. The watermarks
1475 * should be chosen so that we never wait or even reclaim from
1476 * the free list to below its target minimum.
1477 */
1478 if (numvnodes + 1 <= desiredvnodes)
1479 ;
1480 else if (freevnodes > 0)
1481 vnlru_free_locked(1, NULL);
1482 else {
1483 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag &
1484 MNTK_SUSPEND));
1485 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
1486 if (error != 0) {
1487 mtx_unlock(&vnode_free_list_mtx);
1488 return (error);
1489 }
1490 #endif
1491 }
1492 vcheckspace();
1493 atomic_add_long(&numvnodes, 1);
1494 mtx_unlock(&vnode_free_list_mtx);
1495 alloc:
1496 counter_u64_add(vnodes_created, 1);
1497 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK);
1498 /*
1499 * Locks are given the generic name "vnode" when created.
1500 * Follow the historic practice of using the filesystem
1501 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
1502 *
1503 * Locks live in a witness group keyed on their name. Thus,
1504 * when a lock is renamed, it must also move from the witness
1505 * group of its old name to the witness group of its new name.
1506 *
1507 * The change only needs to be made when the vnode moves
1508 * from one filesystem type to another. We ensure that each
1509 * filesystem use a single static name pointer for its tag so
1510 * that we can compare pointers rather than doing a strcmp().
1511 */
1512 lo = &vp->v_vnlock->lock_object;
1513 if (lo->lo_name != tag) {
1514 lo->lo_name = tag;
1515 WITNESS_DESTROY(lo);
1516 WITNESS_INIT(lo, tag);
1517 }
1518 /*
1519 * By default, don't allow shared locks unless filesystems opt-in.
1520 */
1521 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
1522 /*
1523 * Finalize various vnode identity bits.
1524 */
1525 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
1526 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
1527 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
1528 vp->v_type = VNON;
1529 vp->v_tag = tag;
1530 vp->v_op = vops;
1531 v_init_counters(vp);
1532 vp->v_bufobj.bo_ops = &buf_ops_bio;
1533 #ifdef DIAGNOSTIC
1534 if (mp == NULL && vops != &dead_vnodeops)
1535 printf("NULL mp in getnewvnode(9), tag %s\n", tag);
1536 #endif
1537 #ifdef MAC
1538 mac_vnode_init(vp);
1539 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1540 mac_vnode_associate_singlelabel(mp, vp);
1541 #endif
1542 if (mp != NULL) {
1543 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
1544 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1545 vp->v_vflag |= VV_NOKNOTE;
1546 }
1547
1548 /*
1549 * For the filesystems which do not use vfs_hash_insert(),
1550 * still initialize v_hash to have vfs_hash_index() useful.
1551 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
1552 * its own hashing.
1553 */
1554 vp->v_hash = (uintptr_t)vp >> vnsz2log;
1555
1556 *vpp = vp;
1557 return (0);
1558 }
1559
1560 /*
1561 * Delete from old mount point vnode list, if on one.
1562 */
1563 static void
1564 delmntque(struct vnode *vp)
1565 {
1566 struct mount *mp;
1567 int active;
1568
1569 mp = vp->v_mount;
1570 if (mp == NULL)
1571 return;
1572 MNT_ILOCK(mp);
1573 VI_LOCK(vp);
1574 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
1575 ("Active vnode list size %d > Vnode list size %d",
1576 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
1577 active = vp->v_iflag & VI_ACTIVE;
1578 vp->v_iflag &= ~VI_ACTIVE;
1579 if (active) {
1580 mtx_lock(&vnode_free_list_mtx);
1581 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
1582 mp->mnt_activevnodelistsize--;
1583 mtx_unlock(&vnode_free_list_mtx);
1584 }
1585 vp->v_mount = NULL;
1586 VI_UNLOCK(vp);
1587 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1588 ("bad mount point vnode list size"));
1589 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1590 mp->mnt_nvnodelistsize--;
1591 MNT_REL(mp);
1592 MNT_IUNLOCK(mp);
1593 }
1594
1595 static void
1596 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1597 {
1598
1599 vp->v_data = NULL;
1600 vp->v_op = &dead_vnodeops;
1601 vgone(vp);
1602 vput(vp);
1603 }
1604
1605 /*
1606 * Insert into list of vnodes for the new mount point, if available.
1607 */
1608 int
1609 insmntque1(struct vnode *vp, struct mount *mp,
1610 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1611 {
1612
1613 KASSERT(vp->v_mount == NULL,
1614 ("insmntque: vnode already on per mount vnode list"));
1615 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1616 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
1617
1618 /*
1619 * We acquire the vnode interlock early to ensure that the
1620 * vnode cannot be recycled by another process releasing a
1621 * holdcnt on it before we get it on both the vnode list
1622 * and the active vnode list. The mount mutex protects only
1623 * manipulation of the vnode list and the vnode freelist
1624 * mutex protects only manipulation of the active vnode list.
1625 * Hence the need to hold the vnode interlock throughout.
1626 */
1627 MNT_ILOCK(mp);
1628 VI_LOCK(vp);
1629 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1630 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1631 mp->mnt_nvnodelistsize == 0)) &&
1632 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
1633 VI_UNLOCK(vp);
1634 MNT_IUNLOCK(mp);
1635 if (dtr != NULL)
1636 dtr(vp, dtr_arg);
1637 return (EBUSY);
1638 }
1639 vp->v_mount = mp;
1640 MNT_REF(mp);
1641 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1642 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1643 ("neg mount point vnode list size"));
1644 mp->mnt_nvnodelistsize++;
1645 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1646 ("Activating already active vnode"));
1647 vp->v_iflag |= VI_ACTIVE;
1648 mtx_lock(&vnode_free_list_mtx);
1649 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
1650 mp->mnt_activevnodelistsize++;
1651 mtx_unlock(&vnode_free_list_mtx);
1652 VI_UNLOCK(vp);
1653 MNT_IUNLOCK(mp);
1654 return (0);
1655 }
1656
1657 int
1658 insmntque(struct vnode *vp, struct mount *mp)
1659 {
1660
1661 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1662 }
1663
1664 /*
1665 * Flush out and invalidate all buffers associated with a bufobj
1666 * Called with the underlying object locked.
1667 */
1668 int
1669 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1670 {
1671 int error;
1672
1673 BO_LOCK(bo);
1674 if (flags & V_SAVE) {
1675 error = bufobj_wwait(bo, slpflag, slptimeo);
1676 if (error) {
1677 BO_UNLOCK(bo);
1678 return (error);
1679 }
1680 if (bo->bo_dirty.bv_cnt > 0) {
1681 BO_UNLOCK(bo);
1682 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1683 return (error);
1684 /*
1685 * XXX We could save a lock/unlock if this was only
1686 * enabled under INVARIANTS
1687 */
1688 BO_LOCK(bo);
1689 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1690 panic("vinvalbuf: dirty bufs");
1691 }
1692 }
1693 /*
1694 * If you alter this loop please notice that interlock is dropped and
1695 * reacquired in flushbuflist. Special care is needed to ensure that
1696 * no race conditions occur from this.
1697 */
1698 do {
1699 error = flushbuflist(&bo->bo_clean,
1700 flags, bo, slpflag, slptimeo);
1701 if (error == 0 && !(flags & V_CLEANONLY))
1702 error = flushbuflist(&bo->bo_dirty,
1703 flags, bo, slpflag, slptimeo);
1704 if (error != 0 && error != EAGAIN) {
1705 BO_UNLOCK(bo);
1706 return (error);
1707 }
1708 } while (error != 0);
1709
1710 /*
1711 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1712 * have write I/O in-progress but if there is a VM object then the
1713 * VM object can also have read-I/O in-progress.
1714 */
1715 do {
1716 bufobj_wwait(bo, 0, 0);
1717 if ((flags & V_VMIO) == 0) {
1718 BO_UNLOCK(bo);
1719 if (bo->bo_object != NULL) {
1720 VM_OBJECT_WLOCK(bo->bo_object);
1721 vm_object_pip_wait(bo->bo_object, "bovlbx");
1722 VM_OBJECT_WUNLOCK(bo->bo_object);
1723 }
1724 BO_LOCK(bo);
1725 }
1726 } while (bo->bo_numoutput > 0);
1727 BO_UNLOCK(bo);
1728
1729 /*
1730 * Destroy the copy in the VM cache, too.
1731 */
1732 if (bo->bo_object != NULL &&
1733 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
1734 VM_OBJECT_WLOCK(bo->bo_object);
1735 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
1736 OBJPR_CLEANONLY : 0);
1737 VM_OBJECT_WUNLOCK(bo->bo_object);
1738 }
1739
1740 #ifdef INVARIANTS
1741 BO_LOCK(bo);
1742 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO |
1743 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 ||
1744 bo->bo_clean.bv_cnt > 0))
1745 panic("vinvalbuf: flush failed");
1746 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
1747 bo->bo_dirty.bv_cnt > 0)
1748 panic("vinvalbuf: flush dirty failed");
1749 BO_UNLOCK(bo);
1750 #endif
1751 return (0);
1752 }
1753
1754 /*
1755 * Flush out and invalidate all buffers associated with a vnode.
1756 * Called with the underlying object locked.
1757 */
1758 int
1759 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1760 {
1761
1762 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1763 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1764 if (vp->v_object != NULL && vp->v_object->handle != vp)
1765 return (0);
1766 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1767 }
1768
1769 /*
1770 * Flush out buffers on the specified list.
1771 *
1772 */
1773 static int
1774 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1775 int slptimeo)
1776 {
1777 struct buf *bp, *nbp;
1778 int retval, error;
1779 daddr_t lblkno;
1780 b_xflags_t xflags;
1781
1782 ASSERT_BO_WLOCKED(bo);
1783
1784 retval = 0;
1785 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1786 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1787 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1788 continue;
1789 }
1790 if (nbp != NULL) {
1791 lblkno = nbp->b_lblkno;
1792 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
1793 }
1794 retval = EAGAIN;
1795 error = BUF_TIMELOCK(bp,
1796 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
1797 "flushbuf", slpflag, slptimeo);
1798 if (error) {
1799 BO_LOCK(bo);
1800 return (error != ENOLCK ? error : EAGAIN);
1801 }
1802 KASSERT(bp->b_bufobj == bo,
1803 ("bp %p wrong b_bufobj %p should be %p",
1804 bp, bp->b_bufobj, bo));
1805 /*
1806 * XXX Since there are no node locks for NFS, I
1807 * believe there is a slight chance that a delayed
1808 * write will occur while sleeping just above, so
1809 * check for it.
1810 */
1811 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1812 (flags & V_SAVE)) {
1813 bremfree(bp);
1814 bp->b_flags |= B_ASYNC;
1815 bwrite(bp);
1816 BO_LOCK(bo);
1817 return (EAGAIN); /* XXX: why not loop ? */
1818 }
1819 bremfree(bp);
1820 bp->b_flags |= (B_INVAL | B_RELBUF);
1821 bp->b_flags &= ~B_ASYNC;
1822 brelse(bp);
1823 BO_LOCK(bo);
1824 if (nbp == NULL)
1825 break;
1826 nbp = gbincore(bo, lblkno);
1827 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1828 != xflags)
1829 break; /* nbp invalid */
1830 }
1831 return (retval);
1832 }
1833
1834 int
1835 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
1836 {
1837 struct buf *bp;
1838 int error;
1839 daddr_t lblkno;
1840
1841 ASSERT_BO_LOCKED(bo);
1842
1843 for (lblkno = startn;;) {
1844 again:
1845 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
1846 if (bp == NULL || bp->b_lblkno >= endn ||
1847 bp->b_lblkno < startn)
1848 break;
1849 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
1850 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
1851 if (error != 0) {
1852 BO_RLOCK(bo);
1853 if (error == ENOLCK)
1854 goto again;
1855 return (error);
1856 }
1857 KASSERT(bp->b_bufobj == bo,
1858 ("bp %p wrong b_bufobj %p should be %p",
1859 bp, bp->b_bufobj, bo));
1860 lblkno = bp->b_lblkno + 1;
1861 if ((bp->b_flags & B_MANAGED) == 0)
1862 bremfree(bp);
1863 bp->b_flags |= B_RELBUF;
1864 /*
1865 * In the VMIO case, use the B_NOREUSE flag to hint that the
1866 * pages backing each buffer in the range are unlikely to be
1867 * reused. Dirty buffers will have the hint applied once
1868 * they've been written.
1869 */
1870 if ((bp->b_flags & B_VMIO) != 0)
1871 bp->b_flags |= B_NOREUSE;
1872 brelse(bp);
1873 BO_RLOCK(bo);
1874 }
1875 return (0);
1876 }
1877
1878 /*
1879 * Truncate a file's buffer and pages to a specified length. This
1880 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1881 * sync activity.
1882 */
1883 int
1884 vtruncbuf(struct vnode *vp, off_t length, int blksize)
1885 {
1886 struct buf *bp, *nbp;
1887 int anyfreed;
1888 daddr_t trunclbn;
1889 struct bufobj *bo;
1890
1891 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__,
1892 vp, blksize, (uintmax_t)length);
1893
1894 /*
1895 * Round up to the *next* lbn.
1896 */
1897 trunclbn = howmany(length, blksize);
1898
1899 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1900 restart:
1901 bo = &vp->v_bufobj;
1902 BO_LOCK(bo);
1903 anyfreed = 1;
1904 for (;anyfreed;) {
1905 anyfreed = 0;
1906 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1907 if (bp->b_lblkno < trunclbn)
1908 continue;
1909 if (BUF_LOCK(bp,
1910 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1911 BO_LOCKPTR(bo)) == ENOLCK)
1912 goto restart;
1913
1914 bremfree(bp);
1915 bp->b_flags |= (B_INVAL | B_RELBUF);
1916 bp->b_flags &= ~B_ASYNC;
1917 brelse(bp);
1918 anyfreed = 1;
1919
1920 BO_LOCK(bo);
1921 if (nbp != NULL &&
1922 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1923 (nbp->b_vp != vp) ||
1924 (nbp->b_flags & B_DELWRI))) {
1925 BO_UNLOCK(bo);
1926 goto restart;
1927 }
1928 }
1929
1930 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1931 if (bp->b_lblkno < trunclbn)
1932 continue;
1933 if (BUF_LOCK(bp,
1934 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1935 BO_LOCKPTR(bo)) == ENOLCK)
1936 goto restart;
1937 bremfree(bp);
1938 bp->b_flags |= (B_INVAL | B_RELBUF);
1939 bp->b_flags &= ~B_ASYNC;
1940 brelse(bp);
1941 anyfreed = 1;
1942
1943 BO_LOCK(bo);
1944 if (nbp != NULL &&
1945 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1946 (nbp->b_vp != vp) ||
1947 (nbp->b_flags & B_DELWRI) == 0)) {
1948 BO_UNLOCK(bo);
1949 goto restart;
1950 }
1951 }
1952 }
1953
1954 if (length > 0) {
1955 restartsync:
1956 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1957 if (bp->b_lblkno > 0)
1958 continue;
1959 /*
1960 * Since we hold the vnode lock this should only
1961 * fail if we're racing with the buf daemon.
1962 */
1963 if (BUF_LOCK(bp,
1964 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1965 BO_LOCKPTR(bo)) == ENOLCK) {
1966 goto restart;
1967 }
1968 VNASSERT((bp->b_flags & B_DELWRI), vp,
1969 ("buf(%p) on dirty queue without DELWRI", bp));
1970
1971 bremfree(bp);
1972 bawrite(bp);
1973 BO_LOCK(bo);
1974 goto restartsync;
1975 }
1976 }
1977
1978 bufobj_wwait(bo, 0, 0);
1979 BO_UNLOCK(bo);
1980 vnode_pager_setsize(vp, length);
1981
1982 return (0);
1983 }
1984
1985 static void
1986 buf_vlist_remove(struct buf *bp)
1987 {
1988 struct bufv *bv;
1989
1990 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1991 ASSERT_BO_WLOCKED(bp->b_bufobj);
1992 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1993 (BX_VNDIRTY|BX_VNCLEAN),
1994 ("buf_vlist_remove: Buf %p is on two lists", bp));
1995 if (bp->b_xflags & BX_VNDIRTY)
1996 bv = &bp->b_bufobj->bo_dirty;
1997 else
1998 bv = &bp->b_bufobj->bo_clean;
1999 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
2000 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
2001 bv->bv_cnt--;
2002 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
2003 }
2004
2005 /*
2006 * Add the buffer to the sorted clean or dirty block list.
2007 *
2008 * NOTE: xflags is passed as a constant, optimizing this inline function!
2009 */
2010 static void
2011 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2012 {
2013 struct bufv *bv;
2014 struct buf *n;
2015 int error;
2016
2017 ASSERT_BO_WLOCKED(bo);
2018 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
2019 ("dead bo %p", bo));
2020 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
2021 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
2022 bp->b_xflags |= xflags;
2023 if (xflags & BX_VNDIRTY)
2024 bv = &bo->bo_dirty;
2025 else
2026 bv = &bo->bo_clean;
2027
2028 /*
2029 * Keep the list ordered. Optimize empty list insertion. Assume
2030 * we tend to grow at the tail so lookup_le should usually be cheaper
2031 * than _ge.
2032 */
2033 if (bv->bv_cnt == 0 ||
2034 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
2035 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
2036 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
2037 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
2038 else
2039 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
2040 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
2041 if (error)
2042 panic("buf_vlist_add: Preallocated nodes insufficient.");
2043 bv->bv_cnt++;
2044 }
2045
2046 /*
2047 * Look up a buffer using the buffer tries.
2048 */
2049 struct buf *
2050 gbincore(struct bufobj *bo, daddr_t lblkno)
2051 {
2052 struct buf *bp;
2053
2054 ASSERT_BO_LOCKED(bo);
2055 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
2056 if (bp != NULL)
2057 return (bp);
2058 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
2059 }
2060
2061 /*
2062 * Associate a buffer with a vnode.
2063 */
2064 void
2065 bgetvp(struct vnode *vp, struct buf *bp)
2066 {
2067 struct bufobj *bo;
2068
2069 bo = &vp->v_bufobj;
2070 ASSERT_BO_WLOCKED(bo);
2071 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
2072
2073 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
2074 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
2075 ("bgetvp: bp already attached! %p", bp));
2076
2077 vhold(vp);
2078 bp->b_vp = vp;
2079 bp->b_bufobj = bo;
2080 /*
2081 * Insert onto list for new vnode.
2082 */
2083 buf_vlist_add(bp, bo, BX_VNCLEAN);
2084 }
2085
2086 /*
2087 * Disassociate a buffer from a vnode.
2088 */
2089 void
2090 brelvp(struct buf *bp)
2091 {
2092 struct bufobj *bo;
2093 struct vnode *vp;
2094
2095 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
2096 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
2097
2098 /*
2099 * Delete from old vnode list, if on one.
2100 */
2101 vp = bp->b_vp; /* XXX */
2102 bo = bp->b_bufobj;
2103 BO_LOCK(bo);
2104 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2105 buf_vlist_remove(bp);
2106 else
2107 panic("brelvp: Buffer %p not on queue.", bp);
2108 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2109 bo->bo_flag &= ~BO_ONWORKLST;
2110 mtx_lock(&sync_mtx);
2111 LIST_REMOVE(bo, bo_synclist);
2112 syncer_worklist_len--;
2113 mtx_unlock(&sync_mtx);
2114 }
2115 bp->b_vp = NULL;
2116 bp->b_bufobj = NULL;
2117 BO_UNLOCK(bo);
2118 vdrop(vp);
2119 }
2120
2121 /*
2122 * Add an item to the syncer work queue.
2123 */
2124 static void
2125 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2126 {
2127 int slot;
2128
2129 ASSERT_BO_WLOCKED(bo);
2130
2131 mtx_lock(&sync_mtx);
2132 if (bo->bo_flag & BO_ONWORKLST)
2133 LIST_REMOVE(bo, bo_synclist);
2134 else {
2135 bo->bo_flag |= BO_ONWORKLST;
2136 syncer_worklist_len++;
2137 }
2138
2139 if (delay > syncer_maxdelay - 2)
2140 delay = syncer_maxdelay - 2;
2141 slot = (syncer_delayno + delay) & syncer_mask;
2142
2143 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2144 mtx_unlock(&sync_mtx);
2145 }
2146
2147 static int
2148 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2149 {
2150 int error, len;
2151
2152 mtx_lock(&sync_mtx);
2153 len = syncer_worklist_len - sync_vnode_count;
2154 mtx_unlock(&sync_mtx);
2155 error = SYSCTL_OUT(req, &len, sizeof(len));
2156 return (error);
2157 }
2158
2159 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
2160 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2161
2162 static struct proc *updateproc;
2163 static void sched_sync(void);
2164 static struct kproc_desc up_kp = {
2165 "syncer",
2166 sched_sync,
2167 &updateproc
2168 };
2169 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2170
2171 static int
2172 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2173 {
2174 struct vnode *vp;
2175 struct mount *mp;
2176
2177 *bo = LIST_FIRST(slp);
2178 if (*bo == NULL)
2179 return (0);
2180 vp = (*bo)->__bo_vnode; /* XXX */
2181 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2182 return (1);
2183 /*
2184 * We use vhold in case the vnode does not
2185 * successfully sync. vhold prevents the vnode from
2186 * going away when we unlock the sync_mtx so that
2187 * we can acquire the vnode interlock.
2188 */
2189 vholdl(vp);
2190 mtx_unlock(&sync_mtx);
2191 VI_UNLOCK(vp);
2192 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2193 vdrop(vp);
2194 mtx_lock(&sync_mtx);
2195 return (*bo == LIST_FIRST(slp));
2196 }
2197 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2198 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2199 VOP_UNLOCK(vp, 0);
2200 vn_finished_write(mp);
2201 BO_LOCK(*bo);
2202 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2203 /*
2204 * Put us back on the worklist. The worklist
2205 * routine will remove us from our current
2206 * position and then add us back in at a later
2207 * position.
2208 */
2209 vn_syncer_add_to_worklist(*bo, syncdelay);
2210 }
2211 BO_UNLOCK(*bo);
2212 vdrop(vp);
2213 mtx_lock(&sync_mtx);
2214 return (0);
2215 }
2216
2217 static int first_printf = 1;
2218
2219 /*
2220 * System filesystem synchronizer daemon.
2221 */
2222 static void
2223 sched_sync(void)
2224 {
2225 struct synclist *next, *slp;
2226 struct bufobj *bo;
2227 long starttime;
2228 struct thread *td = curthread;
2229 int last_work_seen;
2230 int net_worklist_len;
2231 int syncer_final_iter;
2232 int error;
2233
2234 last_work_seen = 0;
2235 syncer_final_iter = 0;
2236 syncer_state = SYNCER_RUNNING;
2237 starttime = time_uptime;
2238 td->td_pflags |= TDP_NORUNNINGBUF;
2239
2240 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
2241 SHUTDOWN_PRI_LAST);
2242
2243 mtx_lock(&sync_mtx);
2244 for (;;) {
2245 if (syncer_state == SYNCER_FINAL_DELAY &&
2246 syncer_final_iter == 0) {
2247 mtx_unlock(&sync_mtx);
2248 kproc_suspend_check(td->td_proc);
2249 mtx_lock(&sync_mtx);
2250 }
2251 net_worklist_len = syncer_worklist_len - sync_vnode_count;
2252 if (syncer_state != SYNCER_RUNNING &&
2253 starttime != time_uptime) {
2254 if (first_printf) {
2255 printf("\nSyncing disks, vnodes remaining... ");
2256 first_printf = 0;
2257 }
2258 printf("%d ", net_worklist_len);
2259 }
2260 starttime = time_uptime;
2261
2262 /*
2263 * Push files whose dirty time has expired. Be careful
2264 * of interrupt race on slp queue.
2265 *
2266 * Skip over empty worklist slots when shutting down.
2267 */
2268 do {
2269 slp = &syncer_workitem_pending[syncer_delayno];
2270 syncer_delayno += 1;
2271 if (syncer_delayno == syncer_maxdelay)
2272 syncer_delayno = 0;
2273 next = &syncer_workitem_pending[syncer_delayno];
2274 /*
2275 * If the worklist has wrapped since the
2276 * it was emptied of all but syncer vnodes,
2277 * switch to the FINAL_DELAY state and run
2278 * for one more second.
2279 */
2280 if (syncer_state == SYNCER_SHUTTING_DOWN &&
2281 net_worklist_len == 0 &&
2282 last_work_seen == syncer_delayno) {
2283 syncer_state = SYNCER_FINAL_DELAY;
2284 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
2285 }
2286 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
2287 syncer_worklist_len > 0);
2288
2289 /*
2290 * Keep track of the last time there was anything
2291 * on the worklist other than syncer vnodes.
2292 * Return to the SHUTTING_DOWN state if any
2293 * new work appears.
2294 */
2295 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
2296 last_work_seen = syncer_delayno;
2297 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
2298 syncer_state = SYNCER_SHUTTING_DOWN;
2299 while (!LIST_EMPTY(slp)) {
2300 error = sync_vnode(slp, &bo, td);
2301 if (error == 1) {
2302 LIST_REMOVE(bo, bo_synclist);
2303 LIST_INSERT_HEAD(next, bo, bo_synclist);
2304 continue;
2305 }
2306
2307 if (first_printf == 0) {
2308 /*
2309 * Drop the sync mutex, because some watchdog
2310 * drivers need to sleep while patting
2311 */
2312 mtx_unlock(&sync_mtx);
2313 wdog_kern_pat(WD_LASTVAL);
2314 mtx_lock(&sync_mtx);
2315 }
2316
2317 }
2318 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
2319 syncer_final_iter--;
2320 /*
2321 * The variable rushjob allows the kernel to speed up the
2322 * processing of the filesystem syncer process. A rushjob
2323 * value of N tells the filesystem syncer to process the next
2324 * N seconds worth of work on its queue ASAP. Currently rushjob
2325 * is used by the soft update code to speed up the filesystem
2326 * syncer process when the incore state is getting so far
2327 * ahead of the disk that the kernel memory pool is being
2328 * threatened with exhaustion.
2329 */
2330 if (rushjob > 0) {
2331 rushjob -= 1;
2332 continue;
2333 }
2334 /*
2335 * Just sleep for a short period of time between
2336 * iterations when shutting down to allow some I/O
2337 * to happen.
2338 *
2339 * If it has taken us less than a second to process the
2340 * current work, then wait. Otherwise start right over
2341 * again. We can still lose time if any single round
2342 * takes more than two seconds, but it does not really
2343 * matter as we are just trying to generally pace the
2344 * filesystem activity.
2345 */
2346 if (syncer_state != SYNCER_RUNNING ||
2347 time_uptime == starttime) {
2348 thread_lock(td);
2349 sched_prio(td, PPAUSE);
2350 thread_unlock(td);
2351 }
2352 if (syncer_state != SYNCER_RUNNING)
2353 cv_timedwait(&sync_wakeup, &sync_mtx,
2354 hz / SYNCER_SHUTDOWN_SPEEDUP);
2355 else if (time_uptime == starttime)
2356 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
2357 }
2358 }
2359
2360 /*
2361 * Request the syncer daemon to speed up its work.
2362 * We never push it to speed up more than half of its
2363 * normal turn time, otherwise it could take over the cpu.
2364 */
2365 int
2366 speedup_syncer(void)
2367 {
2368 int ret = 0;
2369
2370 mtx_lock(&sync_mtx);
2371 if (rushjob < syncdelay / 2) {
2372 rushjob += 1;
2373 stat_rush_requests += 1;
2374 ret = 1;
2375 }
2376 mtx_unlock(&sync_mtx);
2377 cv_broadcast(&sync_wakeup);
2378 return (ret);
2379 }
2380
2381 /*
2382 * Tell the syncer to speed up its work and run though its work
2383 * list several times, then tell it to shut down.
2384 */
2385 static void
2386 syncer_shutdown(void *arg, int howto)
2387 {
2388
2389 if (howto & RB_NOSYNC)
2390 return;
2391 mtx_lock(&sync_mtx);
2392 syncer_state = SYNCER_SHUTTING_DOWN;
2393 rushjob = 0;
2394 mtx_unlock(&sync_mtx);
2395 cv_broadcast(&sync_wakeup);
2396 kproc_shutdown(arg, howto);
2397 }
2398
2399 void
2400 syncer_suspend(void)
2401 {
2402
2403 syncer_shutdown(updateproc, 0);
2404 }
2405
2406 void
2407 syncer_resume(void)
2408 {
2409
2410 mtx_lock(&sync_mtx);
2411 first_printf = 1;
2412 syncer_state = SYNCER_RUNNING;
2413 mtx_unlock(&sync_mtx);
2414 cv_broadcast(&sync_wakeup);
2415 kproc_resume(updateproc);
2416 }
2417
2418 /*
2419 * Reassign a buffer from one vnode to another.
2420 * Used to assign file specific control information
2421 * (indirect blocks) to the vnode to which they belong.
2422 */
2423 void
2424 reassignbuf(struct buf *bp)
2425 {
2426 struct vnode *vp;
2427 struct bufobj *bo;
2428 int delay;
2429 #ifdef INVARIANTS
2430 struct bufv *bv;
2431 #endif
2432
2433 vp = bp->b_vp;
2434 bo = bp->b_bufobj;
2435 ++reassignbufcalls;
2436
2437 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
2438 bp, bp->b_vp, bp->b_flags);
2439 /*
2440 * B_PAGING flagged buffers cannot be reassigned because their vp
2441 * is not fully linked in.
2442 */
2443 if (bp->b_flags & B_PAGING)
2444 panic("cannot reassign paging buffer");
2445
2446 /*
2447 * Delete from old vnode list, if on one.
2448 */
2449 BO_LOCK(bo);
2450 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2451 buf_vlist_remove(bp);
2452 else
2453 panic("reassignbuf: Buffer %p not on queue.", bp);
2454 /*
2455 * If dirty, put on list of dirty buffers; otherwise insert onto list
2456 * of clean buffers.
2457 */
2458 if (bp->b_flags & B_DELWRI) {
2459 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
2460 switch (vp->v_type) {
2461 case VDIR:
2462 delay = dirdelay;
2463 break;
2464 case VCHR:
2465 delay = metadelay;
2466 break;
2467 default:
2468 delay = filedelay;
2469 }
2470 vn_syncer_add_to_worklist(bo, delay);
2471 }
2472 buf_vlist_add(bp, bo, BX_VNDIRTY);
2473 } else {
2474 buf_vlist_add(bp, bo, BX_VNCLEAN);
2475
2476 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2477 mtx_lock(&sync_mtx);
2478 LIST_REMOVE(bo, bo_synclist);
2479 syncer_worklist_len--;
2480 mtx_unlock(&sync_mtx);
2481 bo->bo_flag &= ~BO_ONWORKLST;
2482 }
2483 }
2484 #ifdef INVARIANTS
2485 bv = &bo->bo_clean;
2486 bp = TAILQ_FIRST(&bv->bv_hd);
2487 KASSERT(bp == NULL || bp->b_bufobj == bo,
2488 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2489 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2490 KASSERT(bp == NULL || bp->b_bufobj == bo,
2491 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2492 bv = &bo->bo_dirty;
2493 bp = TAILQ_FIRST(&bv->bv_hd);
2494 KASSERT(bp == NULL || bp->b_bufobj == bo,
2495 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2496 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2497 KASSERT(bp == NULL || bp->b_bufobj == bo,
2498 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2499 #endif
2500 BO_UNLOCK(bo);
2501 }
2502
2503 static void
2504 v_init_counters(struct vnode *vp)
2505 {
2506
2507 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
2508 vp, ("%s called for an initialized vnode", __FUNCTION__));
2509 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
2510
2511 refcount_init(&vp->v_holdcnt, 1);
2512 refcount_init(&vp->v_usecount, 1);
2513 }
2514
2515 static void
2516 v_incr_usecount_locked(struct vnode *vp)
2517 {
2518
2519 ASSERT_VI_LOCKED(vp, __func__);
2520 if ((vp->v_iflag & VI_OWEINACT) != 0) {
2521 VNASSERT(vp->v_usecount == 0, vp,
2522 ("vnode with usecount and VI_OWEINACT set"));
2523 vp->v_iflag &= ~VI_OWEINACT;
2524 }
2525 refcount_acquire(&vp->v_usecount);
2526 v_incr_devcount(vp);
2527 }
2528
2529 /*
2530 * Increment the use and hold counts on the vnode, taking care to reference
2531 * the driver's usecount if this is a chardev. The _vhold() will remove
2532 * the vnode from the free list if it is presently free.
2533 */
2534 static void
2535 v_incr_usecount(struct vnode *vp)
2536 {
2537
2538 ASSERT_VI_UNLOCKED(vp, __func__);
2539 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2540
2541 if (vp->v_type != VCHR &&
2542 refcount_acquire_if_not_zero(&vp->v_usecount)) {
2543 VNODE_REFCOUNT_FENCE_ACQ();
2544 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2545 ("vnode with usecount and VI_OWEINACT set"));
2546 } else {
2547 VI_LOCK(vp);
2548 v_incr_usecount_locked(vp);
2549 VI_UNLOCK(vp);
2550 }
2551 }
2552
2553 /*
2554 * Increment si_usecount of the associated device, if any.
2555 */
2556 static void
2557 v_incr_devcount(struct vnode *vp)
2558 {
2559
2560 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2561 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2562 dev_lock();
2563 vp->v_rdev->si_usecount++;
2564 dev_unlock();
2565 }
2566 }
2567
2568 /*
2569 * Decrement si_usecount of the associated device, if any.
2570 */
2571 static void
2572 v_decr_devcount(struct vnode *vp)
2573 {
2574
2575 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2576 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2577 dev_lock();
2578 vp->v_rdev->si_usecount--;
2579 dev_unlock();
2580 }
2581 }
2582
2583 /*
2584 * Grab a particular vnode from the free list, increment its
2585 * reference count and lock it. VI_DOOMED is set if the vnode
2586 * is being destroyed. Only callers who specify LK_RETRY will
2587 * see doomed vnodes. If inactive processing was delayed in
2588 * vput try to do it here.
2589 *
2590 * Notes on lockless counter manipulation:
2591 * _vhold, vputx and other routines make various decisions based
2592 * on either holdcnt or usecount being 0. As long as either counter
2593 * is not transitioning 0->1 nor 1->0, the manipulation can be done
2594 * with atomic operations. Otherwise the interlock is taken covering
2595 * both the atomic and additional actions.
2596 */
2597 int
2598 vget(struct vnode *vp, int flags, struct thread *td)
2599 {
2600 int error, oweinact;
2601
2602 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2603 ("vget: invalid lock operation"));
2604
2605 if ((flags & LK_INTERLOCK) != 0)
2606 ASSERT_VI_LOCKED(vp, __func__);
2607 else
2608 ASSERT_VI_UNLOCKED(vp, __func__);
2609 if ((flags & LK_VNHELD) != 0)
2610 VNASSERT((vp->v_holdcnt > 0), vp,
2611 ("vget: LK_VNHELD passed but vnode not held"));
2612
2613 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2614
2615 if ((flags & LK_VNHELD) == 0)
2616 _vhold(vp, (flags & LK_INTERLOCK) != 0);
2617
2618 if ((error = vn_lock(vp, flags)) != 0) {
2619 vdrop(vp);
2620 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2621 vp);
2622 return (error);
2623 }
2624 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2625 panic("vget: vn_lock failed to return ENOENT\n");
2626 /*
2627 * We don't guarantee that any particular close will
2628 * trigger inactive processing so just make a best effort
2629 * here at preventing a reference to a removed file. If
2630 * we don't succeed no harm is done.
2631 *
2632 * Upgrade our holdcnt to a usecount.
2633 */
2634 if (vp->v_type == VCHR ||
2635 !refcount_acquire_if_not_zero(&vp->v_usecount)) {
2636 VI_LOCK(vp);
2637 if ((vp->v_iflag & VI_OWEINACT) == 0) {
2638 oweinact = 0;
2639 } else {
2640 oweinact = 1;
2641 vp->v_iflag &= ~VI_OWEINACT;
2642 VNODE_REFCOUNT_FENCE_REL();
2643 }
2644 refcount_acquire(&vp->v_usecount);
2645 v_incr_devcount(vp);
2646 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2647 (flags & LK_NOWAIT) == 0)
2648 vinactive(vp, td);
2649 VI_UNLOCK(vp);
2650 }
2651 return (0);
2652 }
2653
2654 /*
2655 * Increase the reference count of a vnode.
2656 */
2657 void
2658 vref(struct vnode *vp)
2659 {
2660
2661 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2662 _vhold(vp, false);
2663 v_incr_usecount(vp);
2664 }
2665
2666 void
2667 vrefl(struct vnode *vp)
2668 {
2669
2670 ASSERT_VI_LOCKED(vp, __func__);
2671 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2672 _vhold(vp, true);
2673 v_incr_usecount_locked(vp);
2674 }
2675
2676 void
2677 vrefact(struct vnode *vp)
2678 {
2679
2680 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2681 if (__predict_false(vp->v_type == VCHR)) {
2682 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp,
2683 ("%s: wrong ref counts", __func__));
2684 vref(vp);
2685 return;
2686 }
2687 #ifdef INVARIANTS
2688 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
2689 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
2690 old = atomic_fetchadd_int(&vp->v_usecount, 1);
2691 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__));
2692 #else
2693 refcount_acquire(&vp->v_holdcnt);
2694 refcount_acquire(&vp->v_usecount);
2695 #endif
2696 }
2697
2698 /*
2699 * Return reference count of a vnode.
2700 *
2701 * The results of this call are only guaranteed when some mechanism is used to
2702 * stop other processes from gaining references to the vnode. This may be the
2703 * case if the caller holds the only reference. This is also useful when stale
2704 * data is acceptable as race conditions may be accounted for by some other
2705 * means.
2706 */
2707 int
2708 vrefcnt(struct vnode *vp)
2709 {
2710
2711 return (vp->v_usecount);
2712 }
2713
2714 #define VPUTX_VRELE 1
2715 #define VPUTX_VPUT 2
2716 #define VPUTX_VUNREF 3
2717
2718 /*
2719 * Decrement the use and hold counts for a vnode.
2720 *
2721 * See an explanation near vget() as to why atomic operation is safe.
2722 */
2723 static void
2724 vputx(struct vnode *vp, int func)
2725 {
2726 int error;
2727
2728 KASSERT(vp != NULL, ("vputx: null vp"));
2729 if (func == VPUTX_VUNREF)
2730 ASSERT_VOP_LOCKED(vp, "vunref");
2731 else if (func == VPUTX_VPUT)
2732 ASSERT_VOP_LOCKED(vp, "vput");
2733 else
2734 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2735 ASSERT_VI_UNLOCKED(vp, __func__);
2736 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2737
2738 if (vp->v_type != VCHR &&
2739 refcount_release_if_not_last(&vp->v_usecount)) {
2740 if (func == VPUTX_VPUT)
2741 VOP_UNLOCK(vp, 0);
2742 vdrop(vp);
2743 return;
2744 }
2745
2746 VI_LOCK(vp);
2747
2748 /*
2749 * We want to hold the vnode until the inactive finishes to
2750 * prevent vgone() races. We drop the use count here and the
2751 * hold count below when we're done.
2752 */
2753 if (!refcount_release(&vp->v_usecount) ||
2754 (vp->v_iflag & VI_DOINGINACT)) {
2755 if (func == VPUTX_VPUT)
2756 VOP_UNLOCK(vp, 0);
2757 v_decr_devcount(vp);
2758 vdropl(vp);
2759 return;
2760 }
2761
2762 v_decr_devcount(vp);
2763
2764 error = 0;
2765
2766 if (vp->v_usecount != 0) {
2767 vn_printf(vp, "vputx: usecount not zero for vnode ");
2768 panic("vputx: usecount not zero");
2769 }
2770
2771 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
2772
2773 /*
2774 * We must call VOP_INACTIVE with the node locked. Mark
2775 * as VI_DOINGINACT to avoid recursion.
2776 */
2777 vp->v_iflag |= VI_OWEINACT;
2778 switch (func) {
2779 case VPUTX_VRELE:
2780 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2781 VI_LOCK(vp);
2782 break;
2783 case VPUTX_VPUT:
2784 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2785 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
2786 LK_NOWAIT);
2787 VI_LOCK(vp);
2788 }
2789 break;
2790 case VPUTX_VUNREF:
2791 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2792 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
2793 VI_LOCK(vp);
2794 }
2795 break;
2796 }
2797 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp,
2798 ("vnode with usecount and VI_OWEINACT set"));
2799 if (error == 0) {
2800 if (vp->v_iflag & VI_OWEINACT)
2801 vinactive(vp, curthread);
2802 if (func != VPUTX_VUNREF)
2803 VOP_UNLOCK(vp, 0);
2804 }
2805 vdropl(vp);
2806 }
2807
2808 /*
2809 * Vnode put/release.
2810 * If count drops to zero, call inactive routine and return to freelist.
2811 */
2812 void
2813 vrele(struct vnode *vp)
2814 {
2815
2816 vputx(vp, VPUTX_VRELE);
2817 }
2818
2819 /*
2820 * Release an already locked vnode. This give the same effects as
2821 * unlock+vrele(), but takes less time and avoids releasing and
2822 * re-aquiring the lock (as vrele() acquires the lock internally.)
2823 */
2824 void
2825 vput(struct vnode *vp)
2826 {
2827
2828 vputx(vp, VPUTX_VPUT);
2829 }
2830
2831 /*
2832 * Release an exclusively locked vnode. Do not unlock the vnode lock.
2833 */
2834 void
2835 vunref(struct vnode *vp)
2836 {
2837
2838 vputx(vp, VPUTX_VUNREF);
2839 }
2840
2841 /*
2842 * Increase the hold count and activate if this is the first reference.
2843 */
2844 void
2845 _vhold(struct vnode *vp, bool locked)
2846 {
2847 struct mount *mp;
2848
2849 if (locked)
2850 ASSERT_VI_LOCKED(vp, __func__);
2851 else
2852 ASSERT_VI_UNLOCKED(vp, __func__);
2853 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2854 if (!locked) {
2855 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) {
2856 VNODE_REFCOUNT_FENCE_ACQ();
2857 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2858 ("_vhold: vnode with holdcnt is free"));
2859 return;
2860 }
2861 VI_LOCK(vp);
2862 }
2863 if ((vp->v_iflag & VI_FREE) == 0) {
2864 refcount_acquire(&vp->v_holdcnt);
2865 if (!locked)
2866 VI_UNLOCK(vp);
2867 return;
2868 }
2869 VNASSERT(vp->v_holdcnt == 0, vp,
2870 ("%s: wrong hold count", __func__));
2871 VNASSERT(vp->v_op != NULL, vp,
2872 ("%s: vnode already reclaimed.", __func__));
2873 /*
2874 * Remove a vnode from the free list, mark it as in use,
2875 * and put it on the active list.
2876 */
2877 mtx_lock(&vnode_free_list_mtx);
2878 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
2879 freevnodes--;
2880 vp->v_iflag &= ~VI_FREE;
2881 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
2882 ("Activating already active vnode"));
2883 vp->v_iflag |= VI_ACTIVE;
2884 mp = vp->v_mount;
2885 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
2886 mp->mnt_activevnodelistsize++;
2887 mtx_unlock(&vnode_free_list_mtx);
2888 refcount_acquire(&vp->v_holdcnt);
2889 if (!locked)
2890 VI_UNLOCK(vp);
2891 }
2892
2893 /*
2894 * Drop the hold count of the vnode. If this is the last reference to
2895 * the vnode we place it on the free list unless it has been vgone'd
2896 * (marked VI_DOOMED) in which case we will free it.
2897 *
2898 * Because the vnode vm object keeps a hold reference on the vnode if
2899 * there is at least one resident non-cached page, the vnode cannot
2900 * leave the active list without the page cleanup done.
2901 */
2902 void
2903 _vdrop(struct vnode *vp, bool locked)
2904 {
2905 struct bufobj *bo;
2906 struct mount *mp;
2907 int active;
2908
2909 if (locked)
2910 ASSERT_VI_LOCKED(vp, __func__);
2911 else
2912 ASSERT_VI_UNLOCKED(vp, __func__);
2913 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2914 if ((int)vp->v_holdcnt <= 0)
2915 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2916 if (!locked) {
2917 if (refcount_release_if_not_last(&vp->v_holdcnt))
2918 return;
2919 VI_LOCK(vp);
2920 }
2921 if (refcount_release(&vp->v_holdcnt) == 0) {
2922 VI_UNLOCK(vp);
2923 return;
2924 }
2925 if ((vp->v_iflag & VI_DOOMED) == 0) {
2926 /*
2927 * Mark a vnode as free: remove it from its active list
2928 * and put it up for recycling on the freelist.
2929 */
2930 VNASSERT(vp->v_op != NULL, vp,
2931 ("vdropl: vnode already reclaimed."));
2932 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2933 ("vnode already free"));
2934 VNASSERT(vp->v_holdcnt == 0, vp,
2935 ("vdropl: freeing when we shouldn't"));
2936 active = vp->v_iflag & VI_ACTIVE;
2937 if ((vp->v_iflag & VI_OWEINACT) == 0) {
2938 vp->v_iflag &= ~VI_ACTIVE;
2939 mp = vp->v_mount;
2940 mtx_lock(&vnode_free_list_mtx);
2941 if (active) {
2942 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp,
2943 v_actfreelist);
2944 mp->mnt_activevnodelistsize--;
2945 }
2946 TAILQ_INSERT_TAIL(&vnode_free_list, vp,
2947 v_actfreelist);
2948 freevnodes++;
2949 vp->v_iflag |= VI_FREE;
2950 mtx_unlock(&vnode_free_list_mtx);
2951 } else {
2952 counter_u64_add(free_owe_inact, 1);
2953 }
2954 VI_UNLOCK(vp);
2955 return;
2956 }
2957 /*
2958 * The vnode has been marked for destruction, so free it.
2959 *
2960 * The vnode will be returned to the zone where it will
2961 * normally remain until it is needed for another vnode. We
2962 * need to cleanup (or verify that the cleanup has already
2963 * been done) any residual data left from its current use
2964 * so as not to contaminate the freshly allocated vnode.
2965 */
2966 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2967 atomic_subtract_long(&numvnodes, 1);
2968 bo = &vp->v_bufobj;
2969 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2970 ("cleaned vnode still on the free list."));
2971 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2972 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
2973 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2974 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2975 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2976 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2977 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2978 ("clean blk trie not empty"));
2979 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2980 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2981 ("dirty blk trie not empty"));
2982 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
2983 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
2984 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
2985 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp,
2986 ("Dangling rangelock waiters"));
2987 VI_UNLOCK(vp);
2988 #ifdef MAC
2989 mac_vnode_destroy(vp);
2990 #endif
2991 if (vp->v_pollinfo != NULL) {
2992 destroy_vpollinfo(vp->v_pollinfo);
2993 vp->v_pollinfo = NULL;
2994 }
2995 #ifdef INVARIANTS
2996 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
2997 vp->v_op = NULL;
2998 #endif
2999 bzero(&vp->v_un, sizeof(vp->v_un));
3000 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
3001 vp->v_iflag = 0;
3002 vp->v_vflag = 0;
3003 bo->bo_flag = 0;
3004 uma_zfree(vnode_zone, vp);
3005 }
3006
3007 /*
3008 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
3009 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
3010 * OWEINACT tracks whether a vnode missed a call to inactive due to a
3011 * failed lock upgrade.
3012 */
3013 void
3014 vinactive(struct vnode *vp, struct thread *td)
3015 {
3016 struct vm_object *obj;
3017
3018 ASSERT_VOP_ELOCKED(vp, "vinactive");
3019 ASSERT_VI_LOCKED(vp, "vinactive");
3020 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
3021 ("vinactive: recursed on VI_DOINGINACT"));
3022 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3023 vp->v_iflag |= VI_DOINGINACT;
3024 vp->v_iflag &= ~VI_OWEINACT;
3025 VI_UNLOCK(vp);
3026 /*
3027 * Before moving off the active list, we must be sure that any
3028 * modified pages are converted into the vnode's dirty
3029 * buffers, since these will no longer be checked once the
3030 * vnode is on the inactive list.
3031 *
3032 * The write-out of the dirty pages is asynchronous. At the
3033 * point that VOP_INACTIVE() is called, there could still be
3034 * pending I/O and dirty pages in the object.
3035 */
3036 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
3037 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
3038 VM_OBJECT_WLOCK(obj);
3039 vm_object_page_clean(obj, 0, 0, 0);
3040 VM_OBJECT_WUNLOCK(obj);
3041 }
3042 VOP_INACTIVE(vp, td);
3043 VI_LOCK(vp);
3044 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
3045 ("vinactive: lost VI_DOINGINACT"));
3046 vp->v_iflag &= ~VI_DOINGINACT;
3047 }
3048
3049 /*
3050 * Remove any vnodes in the vnode table belonging to mount point mp.
3051 *
3052 * If FORCECLOSE is not specified, there should not be any active ones,
3053 * return error if any are found (nb: this is a user error, not a
3054 * system error). If FORCECLOSE is specified, detach any active vnodes
3055 * that are found.
3056 *
3057 * If WRITECLOSE is set, only flush out regular file vnodes open for
3058 * writing.
3059 *
3060 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
3061 *
3062 * `rootrefs' specifies the base reference count for the root vnode
3063 * of this filesystem. The root vnode is considered busy if its
3064 * v_usecount exceeds this value. On a successful return, vflush(, td)
3065 * will call vrele() on the root vnode exactly rootrefs times.
3066 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
3067 * be zero.
3068 */
3069 #ifdef DIAGNOSTIC
3070 static int busyprt = 0; /* print out busy vnodes */
3071 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
3072 #endif
3073
3074 int
3075 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
3076 {
3077 struct vnode *vp, *mvp, *rootvp = NULL;
3078 struct vattr vattr;
3079 int busy = 0, error;
3080
3081 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
3082 rootrefs, flags);
3083 if (rootrefs > 0) {
3084 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
3085 ("vflush: bad args"));
3086 /*
3087 * Get the filesystem root vnode. We can vput() it
3088 * immediately, since with rootrefs > 0, it won't go away.
3089 */
3090 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
3091 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
3092 __func__, error);
3093 return (error);
3094 }
3095 vput(rootvp);
3096 }
3097 loop:
3098 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
3099 vholdl(vp);
3100 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
3101 if (error) {
3102 vdrop(vp);
3103 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
3104 goto loop;
3105 }
3106 /*
3107 * Skip over a vnodes marked VV_SYSTEM.
3108 */
3109 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
3110 VOP_UNLOCK(vp, 0);
3111 vdrop(vp);
3112 continue;
3113 }
3114 /*
3115 * If WRITECLOSE is set, flush out unlinked but still open
3116 * files (even if open only for reading) and regular file
3117 * vnodes open for writing.
3118 */
3119 if (flags & WRITECLOSE) {
3120 if (vp->v_object != NULL) {
3121 VM_OBJECT_WLOCK(vp->v_object);
3122 vm_object_page_clean(vp->v_object, 0, 0, 0);
3123 VM_OBJECT_WUNLOCK(vp->v_object);
3124 }
3125 error = VOP_FSYNC(vp, MNT_WAIT, td);
3126 if (error != 0) {
3127 VOP_UNLOCK(vp, 0);
3128 vdrop(vp);
3129 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
3130 return (error);
3131 }
3132 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
3133 VI_LOCK(vp);
3134
3135 if ((vp->v_type == VNON ||
3136 (error == 0 && vattr.va_nlink > 0)) &&
3137 (vp->v_writecount == 0 || vp->v_type != VREG)) {
3138 VOP_UNLOCK(vp, 0);
3139 vdropl(vp);
3140 continue;
3141 }
3142 } else
3143 VI_LOCK(vp);
3144 /*
3145 * With v_usecount == 0, all we need to do is clear out the
3146 * vnode data structures and we are done.
3147 *
3148 * If FORCECLOSE is set, forcibly close the vnode.
3149 */
3150 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
3151 vgonel(vp);
3152 } else {
3153 busy++;
3154 #ifdef DIAGNOSTIC
3155 if (busyprt)
3156 vn_printf(vp, "vflush: busy vnode ");
3157 #endif
3158 }
3159 VOP_UNLOCK(vp, 0);
3160 vdropl(vp);
3161 }
3162 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
3163 /*
3164 * If just the root vnode is busy, and if its refcount
3165 * is equal to `rootrefs', then go ahead and kill it.
3166 */
3167 VI_LOCK(rootvp);
3168 KASSERT(busy > 0, ("vflush: not busy"));
3169 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
3170 ("vflush: usecount %d < rootrefs %d",
3171 rootvp->v_usecount, rootrefs));
3172 if (busy == 1 && rootvp->v_usecount == rootrefs) {
3173 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
3174 vgone(rootvp);
3175 VOP_UNLOCK(rootvp, 0);
3176 busy = 0;
3177 } else
3178 VI_UNLOCK(rootvp);
3179 }
3180 if (busy) {
3181 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
3182 busy);
3183 return (EBUSY);
3184 }
3185 for (; rootrefs > 0; rootrefs--)
3186 vrele(rootvp);
3187 return (0);
3188 }
3189
3190 /*
3191 * Recycle an unused vnode to the front of the free list.
3192 */
3193 int
3194 vrecycle(struct vnode *vp)
3195 {
3196 int recycled;
3197
3198 ASSERT_VOP_ELOCKED(vp, "vrecycle");
3199 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3200 recycled = 0;
3201 VI_LOCK(vp);
3202 if (vp->v_usecount == 0) {
3203 recycled = 1;
3204 vgonel(vp);
3205 }
3206 VI_UNLOCK(vp);
3207 return (recycled);
3208 }
3209
3210 /*
3211 * Eliminate all activity associated with a vnode
3212 * in preparation for reuse.
3213 */
3214 void
3215 vgone(struct vnode *vp)
3216 {
3217 VI_LOCK(vp);
3218 vgonel(vp);
3219 VI_UNLOCK(vp);
3220 }
3221
3222 static void
3223 notify_lowervp_vfs_dummy(struct mount *mp __unused,
3224 struct vnode *lowervp __unused)
3225 {
3226 }
3227
3228 /*
3229 * Notify upper mounts about reclaimed or unlinked vnode.
3230 */
3231 void
3232 vfs_notify_upper(struct vnode *vp, int event)
3233 {
3234 static struct vfsops vgonel_vfsops = {
3235 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy,
3236 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy,
3237 };
3238 struct mount *mp, *ump, *mmp;
3239
3240 mp = vp->v_mount;
3241 if (mp == NULL)
3242 return;
3243
3244 MNT_ILOCK(mp);
3245 if (TAILQ_EMPTY(&mp->mnt_uppers))
3246 goto unlock;
3247 MNT_IUNLOCK(mp);
3248 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO);
3249 mmp->mnt_op = &vgonel_vfsops;
3250 mmp->mnt_kern_flag |= MNTK_MARKER;
3251 MNT_ILOCK(mp);
3252 mp->mnt_kern_flag |= MNTK_VGONE_UPPER;
3253 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) {
3254 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) {
3255 ump = TAILQ_NEXT(ump, mnt_upper_link);
3256 continue;
3257 }
3258 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link);
3259 MNT_IUNLOCK(mp);
3260 switch (event) {
3261 case VFS_NOTIFY_UPPER_RECLAIM:
3262 VFS_RECLAIM_LOWERVP(ump, vp);
3263 break;
3264 case VFS_NOTIFY_UPPER_UNLINK:
3265 VFS_UNLINK_LOWERVP(ump, vp);
3266 break;
3267 default:
3268 KASSERT(0, ("invalid event %d", event));
3269 break;
3270 }
3271 MNT_ILOCK(mp);
3272 ump = TAILQ_NEXT(mmp, mnt_upper_link);
3273 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link);
3274 }
3275 free(mmp, M_TEMP);
3276 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER;
3277 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) {
3278 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER;
3279 wakeup(&mp->mnt_uppers);
3280 }
3281 unlock:
3282 MNT_IUNLOCK(mp);
3283 }
3284
3285 /*
3286 * vgone, with the vp interlock held.
3287 */
3288 static void
3289 vgonel(struct vnode *vp)
3290 {
3291 struct thread *td;
3292 int oweinact;
3293 int active;
3294 struct mount *mp;
3295
3296 ASSERT_VOP_ELOCKED(vp, "vgonel");
3297 ASSERT_VI_LOCKED(vp, "vgonel");
3298 VNASSERT(vp->v_holdcnt, vp,
3299 ("vgonel: vp %p has no reference.", vp));
3300 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3301 td = curthread;
3302
3303 /*
3304 * Don't vgonel if we're already doomed.
3305 */
3306 if (vp->v_iflag & VI_DOOMED)
3307 return;
3308 vp->v_iflag |= VI_DOOMED;
3309
3310 /*
3311 * Check to see if the vnode is in use. If so, we have to call
3312 * VOP_CLOSE() and VOP_INACTIVE().
3313 */
3314 active = vp->v_usecount;
3315 oweinact = (vp->v_iflag & VI_OWEINACT);
3316 VI_UNLOCK(vp);
3317 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
3318
3319 /*
3320 * If purging an active vnode, it must be closed and
3321 * deactivated before being reclaimed.
3322 */
3323 if (active)
3324 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
3325 if (oweinact || active) {
3326 VI_LOCK(vp);
3327 if ((vp->v_iflag & VI_DOINGINACT) == 0)
3328 vinactive(vp, td);
3329 VI_UNLOCK(vp);
3330 }
3331 if (vp->v_type == VSOCK)
3332 vfs_unp_reclaim(vp);
3333
3334 /*
3335 * Clean out any buffers associated with the vnode.
3336 * If the flush fails, just toss the buffers.
3337 */
3338 mp = NULL;
3339 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
3340 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
3341 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
3342 while (vinvalbuf(vp, 0, 0, 0) != 0)
3343 ;
3344 }
3345
3346 BO_LOCK(&vp->v_bufobj);
3347 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
3348 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
3349 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
3350 vp->v_bufobj.bo_clean.bv_cnt == 0,
3351 ("vp %p bufobj not invalidated", vp));
3352
3353 /*
3354 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate()
3355 * after the object's page queue is flushed.
3356 */
3357 if (vp->v_bufobj.bo_object == NULL)
3358 vp->v_bufobj.bo_flag |= BO_DEAD;
3359 BO_UNLOCK(&vp->v_bufobj);
3360
3361 /*
3362 * Reclaim the vnode.
3363 */
3364 if (VOP_RECLAIM(vp, td))
3365 panic("vgone: cannot reclaim");
3366 if (mp != NULL)
3367 vn_finished_secondary_write(mp);
3368 VNASSERT(vp->v_object == NULL, vp,
3369 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
3370 /*
3371 * Clear the advisory locks and wake up waiting threads.
3372 */
3373 (void)VOP_ADVLOCKPURGE(vp);
3374 vp->v_lockf = NULL;
3375 /*
3376 * Delete from old mount point vnode list.
3377 */
3378 delmntque(vp);
3379 cache_purge(vp);
3380 /*
3381 * Done with purge, reset to the standard lock and invalidate
3382 * the vnode.
3383 */
3384 VI_LOCK(vp);
3385 vp->v_vnlock = &vp->v_lock;
3386 vp->v_op = &dead_vnodeops;
3387 vp->v_tag = "none";
3388 vp->v_type = VBAD;
3389 }
3390
3391 /*
3392 * Calculate the total number of references to a special device.
3393 */
3394 int
3395 vcount(struct vnode *vp)
3396 {
3397 int count;
3398
3399 dev_lock();
3400 count = vp->v_rdev->si_usecount;
3401 dev_unlock();
3402 return (count);
3403 }
3404
3405 /*
3406 * Same as above, but using the struct cdev *as argument
3407 */
3408 int
3409 count_dev(struct cdev *dev)
3410 {
3411 int count;
3412
3413 dev_lock();
3414 count = dev->si_usecount;
3415 dev_unlock();
3416 return(count);
3417 }
3418
3419 /*
3420 * Print out a description of a vnode.
3421 */
3422 static char *typename[] =
3423 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
3424 "VMARKER"};
3425
3426 void
3427 vn_printf(struct vnode *vp, const char *fmt, ...)
3428 {
3429 va_list ap;
3430 char buf[256], buf2[16];
3431 u_long flags;
3432
3433 va_start(ap, fmt);
3434 vprintf(fmt, ap);
3435 va_end(ap);
3436 printf("%p: ", (void *)vp);
3437 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
3438 printf(" usecount %d, writecount %d, refcount %d",
3439 vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
3440 switch (vp->v_type) {
3441 case VDIR:
3442 printf(" mountedhere %p\n", vp->v_mountedhere);
3443 break;
3444 case VCHR:
3445 printf(" rdev %p\n", vp->v_rdev);
3446 break;
3447 case VSOCK:
3448 printf(" socket %p\n", vp->v_socket);
3449 break;
3450 case VFIFO:
3451 printf(" fifoinfo %p\n", vp->v_fifoinfo);
3452 break;
3453 default:
3454 printf("\n");
3455 break;
3456 }
3457 buf[0] = '\0';
3458 buf[1] = '\0';
3459 if (vp->v_vflag & VV_ROOT)
3460 strlcat(buf, "|VV_ROOT", sizeof(buf));
3461 if (vp->v_vflag & VV_ISTTY)
3462 strlcat(buf, "|VV_ISTTY", sizeof(buf));
3463 if (vp->v_vflag & VV_NOSYNC)
3464 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
3465 if (vp->v_vflag & VV_ETERNALDEV)
3466 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
3467 if (vp->v_vflag & VV_CACHEDLABEL)
3468 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
3469 if (vp->v_vflag & VV_TEXT)
3470 strlcat(buf, "|VV_TEXT", sizeof(buf));
3471 if (vp->v_vflag & VV_COPYONWRITE)
3472 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
3473 if (vp->v_vflag & VV_SYSTEM)
3474 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
3475 if (vp->v_vflag & VV_PROCDEP)
3476 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
3477 if (vp->v_vflag & VV_NOKNOTE)
3478 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
3479 if (vp->v_vflag & VV_DELETED)
3480 strlcat(buf, "|VV_DELETED", sizeof(buf));
3481 if (vp->v_vflag & VV_MD)
3482 strlcat(buf, "|VV_MD", sizeof(buf));
3483 if (vp->v_vflag & VV_FORCEINSMQ)
3484 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
3485 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
3486 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
3487 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ);
3488 if (flags != 0) {
3489 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
3490 strlcat(buf, buf2, sizeof(buf));
3491 }
3492 if (vp->v_iflag & VI_MOUNT)
3493 strlcat(buf, "|VI_MOUNT", sizeof(buf));
3494 if (vp->v_iflag & VI_DOOMED)
3495 strlcat(buf, "|VI_DOOMED", sizeof(buf));
3496 if (vp->v_iflag & VI_FREE)
3497 strlcat(buf, "|VI_FREE", sizeof(buf));
3498 if (vp->v_iflag & VI_ACTIVE)
3499 strlcat(buf, "|VI_ACTIVE", sizeof(buf));
3500 if (vp->v_iflag & VI_DOINGINACT)
3501 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
3502 if (vp->v_iflag & VI_OWEINACT)
3503 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
3504 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE |
3505 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT);
3506 if (flags != 0) {
3507 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
3508 strlcat(buf, buf2, sizeof(buf));
3509 }
3510 printf(" flags (%s)\n", buf + 1);
3511 if (mtx_owned(VI_MTX(vp)))
3512 printf(" VI_LOCKed");
3513 if (vp->v_object != NULL)
3514 printf(" v_object %p ref %d pages %d "
3515 "cleanbuf %d dirtybuf %d\n",
3516 vp->v_object, vp->v_object->ref_count,
3517 vp->v_object->resident_page_count,
3518 vp->v_bufobj.bo_clean.bv_cnt,
3519 vp->v_bufobj.bo_dirty.bv_cnt);
3520 printf(" ");
3521 lockmgr_printinfo(vp->v_vnlock);
3522 if (vp->v_data != NULL)
3523 VOP_PRINT(vp);
3524 }
3525
3526 #ifdef DDB
3527 /*
3528 * List all of the locked vnodes in the system.
3529 * Called when debugging the kernel.
3530 */
3531 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
3532 {
3533 struct mount *mp;
3534 struct vnode *vp;
3535
3536 /*
3537 * Note: because this is DDB, we can't obey the locking semantics
3538 * for these structures, which means we could catch an inconsistent
3539 * state and dereference a nasty pointer. Not much to be done
3540 * about that.
3541 */
3542 db_printf("Locked vnodes\n");
3543 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3544 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3545 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
3546 vn_printf(vp, "vnode ");
3547 }
3548 }
3549 }
3550
3551 /*
3552 * Show details about the given vnode.
3553 */
3554 DB_SHOW_COMMAND(vnode, db_show_vnode)
3555 {
3556 struct vnode *vp;
3557
3558 if (!have_addr)
3559 return;
3560 vp = (struct vnode *)addr;
3561 vn_printf(vp, "vnode ");
3562 }
3563
3564 /*
3565 * Show details about the given mount point.
3566 */
3567 DB_SHOW_COMMAND(mount, db_show_mount)
3568 {
3569 struct mount *mp;
3570 struct vfsopt *opt;
3571 struct statfs *sp;
3572 struct vnode *vp;
3573 char buf[512];
3574 uint64_t mflags;
3575 u_int flags;
3576
3577 if (!have_addr) {
3578 /* No address given, print short info about all mount points. */
3579 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3580 db_printf("%p %s on %s (%s)\n", mp,
3581 mp->mnt_stat.f_mntfromname,
3582 mp->mnt_stat.f_mntonname,
3583 mp->mnt_stat.f_fstypename);
3584 if (db_pager_quit)
3585 break;
3586 }
3587 db_printf("\nMore info: show mount <addr>\n");
3588 return;
3589 }
3590
3591 mp = (struct mount *)addr;
3592 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
3593 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
3594
3595 buf[0] = '\0';
3596 mflags = mp->mnt_flag;
3597 #define MNT_FLAG(flag) do { \
3598 if (mflags & (flag)) { \
3599 if (buf[0] != '\0') \
3600 strlcat(buf, ", ", sizeof(buf)); \
3601 strlcat(buf, (#flag) + 4, sizeof(buf)); \
3602 mflags &= ~(flag); \
3603 } \
3604 } while (0)
3605 MNT_FLAG(MNT_RDONLY);
3606 MNT_FLAG(MNT_SYNCHRONOUS);
3607 MNT_FLAG(MNT_NOEXEC);
3608 MNT_FLAG(MNT_NOSUID);
3609 MNT_FLAG(MNT_NFS4ACLS);
3610 MNT_FLAG(MNT_UNION);
3611 MNT_FLAG(MNT_ASYNC);
3612 MNT_FLAG(MNT_SUIDDIR);
3613 MNT_FLAG(MNT_SOFTDEP);
3614 MNT_FLAG(MNT_NOSYMFOLLOW);
3615 MNT_FLAG(MNT_GJOURNAL);
3616 MNT_FLAG(MNT_MULTILABEL);
3617 MNT_FLAG(MNT_ACLS);
3618 MNT_FLAG(MNT_NOATIME);
3619 MNT_FLAG(MNT_NOCLUSTERR);
3620 MNT_FLAG(MNT_NOCLUSTERW);
3621 MNT_FLAG(MNT_SUJ);
3622 MNT_FLAG(MNT_EXRDONLY);
3623 MNT_FLAG(MNT_EXPORTED);
3624 MNT_FLAG(MNT_DEFEXPORTED);
3625 MNT_FLAG(MNT_EXPORTANON);
3626 MNT_FLAG(MNT_EXKERB);
3627 MNT_FLAG(MNT_EXPUBLIC);
3628 MNT_FLAG(MNT_LOCAL);
3629 MNT_FLAG(MNT_QUOTA);
3630 MNT_FLAG(MNT_ROOTFS);
3631 MNT_FLAG(MNT_USER);
3632 MNT_FLAG(MNT_IGNORE);
3633 MNT_FLAG(MNT_UPDATE);
3634 MNT_FLAG(MNT_DELEXPORT);
3635 MNT_FLAG(MNT_RELOAD);
3636 MNT_FLAG(MNT_FORCE);
3637 MNT_FLAG(MNT_SNAPSHOT);
3638 MNT_FLAG(MNT_BYFSID);
3639 #undef MNT_FLAG
3640 if (mflags != 0) {
3641 if (buf[0] != '\0')
3642 strlcat(buf, ", ", sizeof(buf));
3643 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3644 "0x%016jx", mflags);
3645 }
3646 db_printf(" mnt_flag = %s\n", buf);
3647
3648 buf[0] = '\0';
3649 flags = mp->mnt_kern_flag;
3650 #define MNT_KERN_FLAG(flag) do { \
3651 if (flags & (flag)) { \
3652 if (buf[0] != '\0') \
3653 strlcat(buf, ", ", sizeof(buf)); \
3654 strlcat(buf, (#flag) + 5, sizeof(buf)); \
3655 flags &= ~(flag); \
3656 } \
3657 } while (0)
3658 MNT_KERN_FLAG(MNTK_UNMOUNTF);
3659 MNT_KERN_FLAG(MNTK_ASYNC);
3660 MNT_KERN_FLAG(MNTK_SOFTDEP);
3661 MNT_KERN_FLAG(MNTK_NOINSMNTQ);
3662 MNT_KERN_FLAG(MNTK_DRAINING);
3663 MNT_KERN_FLAG(MNTK_REFEXPIRE);
3664 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
3665 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
3666 MNT_KERN_FLAG(MNTK_NO_IOPF);
3667 MNT_KERN_FLAG(MNTK_VGONE_UPPER);
3668 MNT_KERN_FLAG(MNTK_VGONE_WAITER);
3669 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT);
3670 MNT_KERN_FLAG(MNTK_MARKER);
3671 MNT_KERN_FLAG(MNTK_USES_BCACHE);
3672 MNT_KERN_FLAG(MNTK_NOASYNC);
3673 MNT_KERN_FLAG(MNTK_UNMOUNT);
3674 MNT_KERN_FLAG(MNTK_MWAIT);
3675 MNT_KERN_FLAG(MNTK_SUSPEND);
3676 MNT_KERN_FLAG(MNTK_SUSPEND2);
3677 MNT_KERN_FLAG(MNTK_SUSPENDED);
3678 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
3679 MNT_KERN_FLAG(MNTK_NOKNOTE);
3680 #undef MNT_KERN_FLAG
3681 if (flags != 0) {
3682 if (buf[0] != '\0')
3683 strlcat(buf, ", ", sizeof(buf));
3684 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3685 "0x%08x", flags);
3686 }
3687 db_printf(" mnt_kern_flag = %s\n", buf);
3688
3689 db_printf(" mnt_opt = ");
3690 opt = TAILQ_FIRST(mp->mnt_opt);
3691 if (opt != NULL) {
3692 db_printf("%s", opt->name);
3693 opt = TAILQ_NEXT(opt, link);
3694 while (opt != NULL) {
3695 db_printf(", %s", opt->name);
3696 opt = TAILQ_NEXT(opt, link);
3697 }
3698 }
3699 db_printf("\n");
3700
3701 sp = &mp->mnt_stat;
3702 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
3703 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
3704 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
3705 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
3706 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
3707 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
3708 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
3709 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
3710 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
3711 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
3712 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
3713 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
3714
3715 db_printf(" mnt_cred = { uid=%u ruid=%u",
3716 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
3717 if (jailed(mp->mnt_cred))
3718 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
3719 db_printf(" }\n");
3720 db_printf(" mnt_ref = %d\n", mp->mnt_ref);
3721 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
3722 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
3723 db_printf(" mnt_activevnodelistsize = %d\n",
3724 mp->mnt_activevnodelistsize);
3725 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
3726 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
3727 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
3728 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
3729 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref);
3730 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
3731 db_printf(" mnt_secondary_accwrites = %d\n",
3732 mp->mnt_secondary_accwrites);
3733 db_printf(" mnt_gjprovider = %s\n",
3734 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
3735
3736 db_printf("\n\nList of active vnodes\n");
3737 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
3738 if (vp->v_type != VMARKER) {
3739 vn_printf(vp, "vnode ");
3740 if (db_pager_quit)
3741 break;
3742 }
3743 }
3744 db_printf("\n\nList of inactive vnodes\n");
3745 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3746 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
3747 vn_printf(vp, "vnode ");
3748 if (db_pager_quit)
3749 break;
3750 }
3751 }
3752 }
3753 #endif /* DDB */
3754
3755 /*
3756 * Fill in a struct xvfsconf based on a struct vfsconf.
3757 */
3758 static int
3759 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
3760 {
3761 struct xvfsconf xvfsp;
3762
3763 bzero(&xvfsp, sizeof(xvfsp));
3764 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3765 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3766 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3767 xvfsp.vfc_flags = vfsp->vfc_flags;
3768 /*
3769 * These are unused in userland, we keep them
3770 * to not break binary compatibility.
3771 */
3772 xvfsp.vfc_vfsops = NULL;
3773 xvfsp.vfc_next = NULL;
3774 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3775 }
3776
3777 #ifdef COMPAT_FREEBSD32
3778 struct xvfsconf32 {
3779 uint32_t vfc_vfsops;
3780 char vfc_name[MFSNAMELEN];
3781 int32_t vfc_typenum;
3782 int32_t vfc_refcount;
3783 int32_t vfc_flags;
3784 uint32_t vfc_next;
3785 };
3786
3787 static int
3788 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
3789 {
3790 struct xvfsconf32 xvfsp;
3791
3792 bzero(&xvfsp, sizeof(xvfsp));
3793 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3794 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3795 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3796 xvfsp.vfc_flags = vfsp->vfc_flags;
3797 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3798 }
3799 #endif
3800
3801 /*
3802 * Top level filesystem related information gathering.
3803 */
3804 static int
3805 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
3806 {
3807 struct vfsconf *vfsp;
3808 int error;
3809
3810 error = 0;
3811 vfsconf_slock();
3812 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3813 #ifdef COMPAT_FREEBSD32
3814 if (req->flags & SCTL_MASK32)
3815 error = vfsconf2x32(req, vfsp);
3816 else
3817 #endif
3818 error = vfsconf2x(req, vfsp);
3819 if (error)
3820 break;
3821 }
3822 vfsconf_sunlock();
3823 return (error);
3824 }
3825
3826 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
3827 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
3828 "S,xvfsconf", "List of all configured filesystems");
3829
3830 #ifndef BURN_BRIDGES
3831 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
3832
3833 static int
3834 vfs_sysctl(SYSCTL_HANDLER_ARGS)
3835 {
3836 int *name = (int *)arg1 - 1; /* XXX */
3837 u_int namelen = arg2 + 1; /* XXX */
3838 struct vfsconf *vfsp;
3839
3840 log(LOG_WARNING, "userland calling deprecated sysctl, "
3841 "please rebuild world\n");
3842
3843 #if 1 || defined(COMPAT_PRELITE2)
3844 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
3845 if (namelen == 1)
3846 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
3847 #endif
3848
3849 switch (name[1]) {
3850 case VFS_MAXTYPENUM:
3851 if (namelen != 2)
3852 return (ENOTDIR);
3853 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
3854 case VFS_CONF:
3855 if (namelen != 3)
3856 return (ENOTDIR); /* overloaded */
3857 vfsconf_slock();
3858 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3859 if (vfsp->vfc_typenum == name[2])
3860 break;
3861 }
3862 vfsconf_sunlock();
3863 if (vfsp == NULL)
3864 return (EOPNOTSUPP);
3865 #ifdef COMPAT_FREEBSD32
3866 if (req->flags & SCTL_MASK32)
3867 return (vfsconf2x32(req, vfsp));
3868 else
3869 #endif
3870 return (vfsconf2x(req, vfsp));
3871 }
3872 return (EOPNOTSUPP);
3873 }
3874
3875 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
3876 CTLFLAG_MPSAFE, vfs_sysctl,
3877 "Generic filesystem");
3878
3879 #if 1 || defined(COMPAT_PRELITE2)
3880
3881 static int
3882 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
3883 {
3884 int error;
3885 struct vfsconf *vfsp;
3886 struct ovfsconf ovfs;
3887
3888 vfsconf_slock();
3889 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3890 bzero(&ovfs, sizeof(ovfs));
3891 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
3892 strcpy(ovfs.vfc_name, vfsp->vfc_name);
3893 ovfs.vfc_index = vfsp->vfc_typenum;
3894 ovfs.vfc_refcount = vfsp->vfc_refcount;
3895 ovfs.vfc_flags = vfsp->vfc_flags;
3896 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
3897 if (error != 0) {
3898 vfsconf_sunlock();
3899 return (error);
3900 }
3901 }
3902 vfsconf_sunlock();
3903 return (0);
3904 }
3905
3906 #endif /* 1 || COMPAT_PRELITE2 */
3907 #endif /* !BURN_BRIDGES */
3908
3909 #define KINFO_VNODESLOP 10
3910 #ifdef notyet
3911 /*
3912 * Dump vnode list (via sysctl).
3913 */
3914 /* ARGSUSED */
3915 static int
3916 sysctl_vnode(SYSCTL_HANDLER_ARGS)
3917 {
3918 struct xvnode *xvn;
3919 struct mount *mp;
3920 struct vnode *vp;
3921 int error, len, n;
3922
3923 /*
3924 * Stale numvnodes access is not fatal here.
3925 */
3926 req->lock = 0;
3927 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
3928 if (!req->oldptr)
3929 /* Make an estimate */
3930 return (SYSCTL_OUT(req, 0, len));
3931
3932 error = sysctl_wire_old_buffer(req, 0);
3933 if (error != 0)
3934 return (error);
3935 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
3936 n = 0;
3937 mtx_lock(&mountlist_mtx);
3938 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3939 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
3940 continue;
3941 MNT_ILOCK(mp);
3942 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3943 if (n == len)
3944 break;
3945 vref(vp);
3946 xvn[n].xv_size = sizeof *xvn;
3947 xvn[n].xv_vnode = vp;
3948 xvn[n].xv_id = 0; /* XXX compat */
3949 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
3950 XV_COPY(usecount);
3951 XV_COPY(writecount);
3952 XV_COPY(holdcnt);
3953 XV_COPY(mount);
3954 XV_COPY(numoutput);
3955 XV_COPY(type);
3956 #undef XV_COPY
3957 xvn[n].xv_flag = vp->v_vflag;
3958
3959 switch (vp->v_type) {
3960 case VREG:
3961 case VDIR:
3962 case VLNK:
3963 break;
3964 case VBLK:
3965 case VCHR:
3966 if (vp->v_rdev == NULL) {
3967 vrele(vp);
3968 continue;
3969 }
3970 xvn[n].xv_dev = dev2udev(vp->v_rdev);
3971 break;
3972 case VSOCK:
3973 xvn[n].xv_socket = vp->v_socket;
3974 break;
3975 case VFIFO:
3976 xvn[n].xv_fifo = vp->v_fifoinfo;
3977 break;
3978 case VNON:
3979 case VBAD:
3980 default:
3981 /* shouldn't happen? */
3982 vrele(vp);
3983 continue;
3984 }
3985 vrele(vp);
3986 ++n;
3987 }
3988 MNT_IUNLOCK(mp);
3989 mtx_lock(&mountlist_mtx);
3990 vfs_unbusy(mp);
3991 if (n == len)
3992 break;
3993 }
3994 mtx_unlock(&mountlist_mtx);
3995
3996 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
3997 free(xvn, M_TEMP);
3998 return (error);
3999 }
4000
4001 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD |
4002 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode",
4003 "");
4004 #endif
4005
4006 static void
4007 unmount_or_warn(struct mount *mp)
4008 {
4009 int error;
4010
4011 error = dounmount(mp, MNT_FORCE, curthread);
4012 if (error != 0) {
4013 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
4014 if (error == EBUSY)
4015 printf("BUSY)\n");
4016 else
4017 printf("%d)\n", error);
4018 }
4019 }
4020
4021 /*
4022 * Unmount all filesystems. The list is traversed in reverse order
4023 * of mounting to avoid dependencies.
4024 */
4025 void
4026 vfs_unmountall(void)
4027 {
4028 struct mount *mp, *tmp;
4029
4030 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
4031
4032 /*
4033 * Since this only runs when rebooting, it is not interlocked.
4034 */
4035 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
4036 vfs_ref(mp);
4037
4038 /*
4039 * Forcibly unmounting "/dev" before "/" would prevent clean
4040 * unmount of the latter.
4041 */
4042 if (mp == rootdevmp)
4043 continue;
4044
4045 unmount_or_warn(mp);
4046 }
4047
4048 if (rootdevmp != NULL)
4049 unmount_or_warn(rootdevmp);
4050 }
4051
4052 /*
4053 * perform msync on all vnodes under a mount point
4054 * the mount point must be locked.
4055 */
4056 void
4057 vfs_msync(struct mount *mp, int flags)
4058 {
4059 struct vnode *vp, *mvp;
4060 struct vm_object *obj;
4061
4062 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
4063 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
4064 obj = vp->v_object;
4065 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
4066 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
4067 if (!vget(vp,
4068 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
4069 curthread)) {
4070 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
4071 vput(vp);
4072 continue;
4073 }
4074
4075 obj = vp->v_object;
4076 if (obj != NULL) {
4077 VM_OBJECT_WLOCK(obj);
4078 vm_object_page_clean(obj, 0, 0,
4079 flags == MNT_WAIT ?
4080 OBJPC_SYNC : OBJPC_NOSYNC);
4081 VM_OBJECT_WUNLOCK(obj);
4082 }
4083 vput(vp);
4084 }
4085 } else
4086 VI_UNLOCK(vp);
4087 }
4088 }
4089
4090 static void
4091 destroy_vpollinfo_free(struct vpollinfo *vi)
4092 {
4093
4094 knlist_destroy(&vi->vpi_selinfo.si_note);
4095 mtx_destroy(&vi->vpi_lock);
4096 uma_zfree(vnodepoll_zone, vi);
4097 }
4098
4099 static void
4100 destroy_vpollinfo(struct vpollinfo *vi)
4101 {
4102
4103 knlist_clear(&vi->vpi_selinfo.si_note, 1);
4104 seldrain(&vi->vpi_selinfo);
4105 destroy_vpollinfo_free(vi);
4106 }
4107
4108 /*
4109 * Initialize per-vnode helper structure to hold poll-related state.
4110 */
4111 void
4112 v_addpollinfo(struct vnode *vp)
4113 {
4114 struct vpollinfo *vi;
4115
4116 if (vp->v_pollinfo != NULL)
4117 return;
4118 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO);
4119 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
4120 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
4121 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
4122 VI_LOCK(vp);
4123 if (vp->v_pollinfo != NULL) {
4124 VI_UNLOCK(vp);
4125 destroy_vpollinfo_free(vi);
4126 return;
4127 }
4128 vp->v_pollinfo = vi;
4129 VI_UNLOCK(vp);
4130 }
4131
4132 /*
4133 * Record a process's interest in events which might happen to
4134 * a vnode. Because poll uses the historic select-style interface
4135 * internally, this routine serves as both the ``check for any
4136 * pending events'' and the ``record my interest in future events''
4137 * functions. (These are done together, while the lock is held,
4138 * to avoid race conditions.)
4139 */
4140 int
4141 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
4142 {
4143
4144 v_addpollinfo(vp);
4145 mtx_lock(&vp->v_pollinfo->vpi_lock);
4146 if (vp->v_pollinfo->vpi_revents & events) {
4147 /*
4148 * This leaves events we are not interested
4149 * in available for the other process which
4150 * which presumably had requested them
4151 * (otherwise they would never have been
4152 * recorded).
4153 */
4154 events &= vp->v_pollinfo->vpi_revents;
4155 vp->v_pollinfo->vpi_revents &= ~events;
4156
4157 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4158 return (events);
4159 }
4160 vp->v_pollinfo->vpi_events |= events;
4161 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
4162 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4163 return (0);
4164 }
4165
4166 /*
4167 * Routine to create and manage a filesystem syncer vnode.
4168 */
4169 #define sync_close ((int (*)(struct vop_close_args *))nullop)
4170 static int sync_fsync(struct vop_fsync_args *);
4171 static int sync_inactive(struct vop_inactive_args *);
4172 static int sync_reclaim(struct vop_reclaim_args *);
4173
4174 static struct vop_vector sync_vnodeops = {
4175 .vop_bypass = VOP_EOPNOTSUPP,
4176 .vop_close = sync_close, /* close */
4177 .vop_fsync = sync_fsync, /* fsync */
4178 .vop_inactive = sync_inactive, /* inactive */
4179 .vop_reclaim = sync_reclaim, /* reclaim */
4180 .vop_lock1 = vop_stdlock, /* lock */
4181 .vop_unlock = vop_stdunlock, /* unlock */
4182 .vop_islocked = vop_stdislocked, /* islocked */
4183 };
4184
4185 /*
4186 * Create a new filesystem syncer vnode for the specified mount point.
4187 */
4188 void
4189 vfs_allocate_syncvnode(struct mount *mp)
4190 {
4191 struct vnode *vp;
4192 struct bufobj *bo;
4193 static long start, incr, next;
4194 int error;
4195
4196 /* Allocate a new vnode */
4197 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
4198 if (error != 0)
4199 panic("vfs_allocate_syncvnode: getnewvnode() failed");
4200 vp->v_type = VNON;
4201 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4202 vp->v_vflag |= VV_FORCEINSMQ;
4203 error = insmntque(vp, mp);
4204 if (error != 0)
4205 panic("vfs_allocate_syncvnode: insmntque() failed");
4206 vp->v_vflag &= ~VV_FORCEINSMQ;
4207 VOP_UNLOCK(vp, 0);
4208 /*
4209 * Place the vnode onto the syncer worklist. We attempt to
4210 * scatter them about on the list so that they will go off
4211 * at evenly distributed times even if all the filesystems
4212 * are mounted at once.
4213 */
4214 next += incr;
4215 if (next == 0 || next > syncer_maxdelay) {
4216 start /= 2;
4217 incr /= 2;
4218 if (start == 0) {
4219 start = syncer_maxdelay / 2;
4220 incr = syncer_maxdelay;
4221 }
4222 next = start;
4223 }
4224 bo = &vp->v_bufobj;
4225 BO_LOCK(bo);
4226 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
4227 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
4228 mtx_lock(&sync_mtx);
4229 sync_vnode_count++;
4230 if (mp->mnt_syncer == NULL) {
4231 mp->mnt_syncer = vp;
4232 vp = NULL;
4233 }
4234 mtx_unlock(&sync_mtx);
4235 BO_UNLOCK(bo);
4236 if (vp != NULL) {
4237 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4238 vgone(vp);
4239 vput(vp);
4240 }
4241 }
4242
4243 void
4244 vfs_deallocate_syncvnode(struct mount *mp)
4245 {
4246 struct vnode *vp;
4247
4248 mtx_lock(&sync_mtx);
4249 vp = mp->mnt_syncer;
4250 if (vp != NULL)
4251 mp->mnt_syncer = NULL;
4252 mtx_unlock(&sync_mtx);
4253 if (vp != NULL)
4254 vrele(vp);
4255 }
4256
4257 /*
4258 * Do a lazy sync of the filesystem.
4259 */
4260 static int
4261 sync_fsync(struct vop_fsync_args *ap)
4262 {
4263 struct vnode *syncvp = ap->a_vp;
4264 struct mount *mp = syncvp->v_mount;
4265 int error, save;
4266 struct bufobj *bo;
4267
4268 /*
4269 * We only need to do something if this is a lazy evaluation.
4270 */
4271 if (ap->a_waitfor != MNT_LAZY)
4272 return (0);
4273
4274 /*
4275 * Move ourselves to the back of the sync list.
4276 */
4277 bo = &syncvp->v_bufobj;
4278 BO_LOCK(bo);
4279 vn_syncer_add_to_worklist(bo, syncdelay);
4280 BO_UNLOCK(bo);
4281
4282 /*
4283 * Walk the list of vnodes pushing all that are dirty and
4284 * not already on the sync list.
4285 */
4286 if (vfs_busy(mp, MBF_NOWAIT) != 0)
4287 return (0);
4288 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
4289 vfs_unbusy(mp);
4290 return (0);
4291 }
4292 save = curthread_pflags_set(TDP_SYNCIO);
4293 vfs_msync(mp, MNT_NOWAIT);
4294 error = VFS_SYNC(mp, MNT_LAZY);
4295 curthread_pflags_restore(save);
4296 vn_finished_write(mp);
4297 vfs_unbusy(mp);
4298 return (error);
4299 }
4300
4301 /*
4302 * The syncer vnode is no referenced.
4303 */
4304 static int
4305 sync_inactive(struct vop_inactive_args *ap)
4306 {
4307
4308 vgone(ap->a_vp);
4309 return (0);
4310 }
4311
4312 /*
4313 * The syncer vnode is no longer needed and is being decommissioned.
4314 *
4315 * Modifications to the worklist must be protected by sync_mtx.
4316 */
4317 static int
4318 sync_reclaim(struct vop_reclaim_args *ap)
4319 {
4320 struct vnode *vp = ap->a_vp;
4321 struct bufobj *bo;
4322
4323 bo = &vp->v_bufobj;
4324 BO_LOCK(bo);
4325 mtx_lock(&sync_mtx);
4326 if (vp->v_mount->mnt_syncer == vp)
4327 vp->v_mount->mnt_syncer = NULL;
4328 if (bo->bo_flag & BO_ONWORKLST) {
4329 LIST_REMOVE(bo, bo_synclist);
4330 syncer_worklist_len--;
4331 sync_vnode_count--;
4332 bo->bo_flag &= ~BO_ONWORKLST;
4333 }
4334 mtx_unlock(&sync_mtx);
4335 BO_UNLOCK(bo);
4336
4337 return (0);
4338 }
4339
4340 /*
4341 * Check if vnode represents a disk device
4342 */
4343 int
4344 vn_isdisk(struct vnode *vp, int *errp)
4345 {
4346 int error;
4347
4348 if (vp->v_type != VCHR) {
4349 error = ENOTBLK;
4350 goto out;
4351 }
4352 error = 0;
4353 dev_lock();
4354 if (vp->v_rdev == NULL)
4355 error = ENXIO;
4356 else if (vp->v_rdev->si_devsw == NULL)
4357 error = ENXIO;
4358 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
4359 error = ENOTBLK;
4360 dev_unlock();
4361 out:
4362 if (errp != NULL)
4363 *errp = error;
4364 return (error == 0);
4365 }
4366
4367 /*
4368 * Common filesystem object access control check routine. Accepts a
4369 * vnode's type, "mode", uid and gid, requested access mode, credentials,
4370 * and optional call-by-reference privused argument allowing vaccess()
4371 * to indicate to the caller whether privilege was used to satisfy the
4372 * request (obsoleted). Returns 0 on success, or an errno on failure.
4373 */
4374 int
4375 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
4376 accmode_t accmode, struct ucred *cred, int *privused)
4377 {
4378 accmode_t dac_granted;
4379 accmode_t priv_granted;
4380
4381 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
4382 ("invalid bit in accmode"));
4383 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
4384 ("VAPPEND without VWRITE"));
4385
4386 /*
4387 * Look for a normal, non-privileged way to access the file/directory
4388 * as requested. If it exists, go with that.
4389 */
4390
4391 if (privused != NULL)
4392 *privused = 0;
4393
4394 dac_granted = 0;
4395
4396 /* Check the owner. */
4397 if (cred->cr_uid == file_uid) {
4398 dac_granted |= VADMIN;
4399 if (file_mode & S_IXUSR)
4400 dac_granted |= VEXEC;
4401 if (file_mode & S_IRUSR)
4402 dac_granted |= VREAD;
4403 if (file_mode & S_IWUSR)
4404 dac_granted |= (VWRITE | VAPPEND);
4405
4406 if ((accmode & dac_granted) == accmode)
4407 return (0);
4408
4409 goto privcheck;
4410 }
4411
4412 /* Otherwise, check the groups (first match) */
4413 if (groupmember(file_gid, cred)) {
4414 if (file_mode & S_IXGRP)
4415 dac_granted |= VEXEC;
4416 if (file_mode & S_IRGRP)
4417 dac_granted |= VREAD;
4418 if (file_mode & S_IWGRP)
4419 dac_granted |= (VWRITE | VAPPEND);
4420
4421 if ((accmode & dac_granted) == accmode)
4422 return (0);
4423
4424 goto privcheck;
4425 }
4426
4427 /* Otherwise, check everyone else. */
4428 if (file_mode & S_IXOTH)
4429 dac_granted |= VEXEC;
4430 if (file_mode & S_IROTH)
4431 dac_granted |= VREAD;
4432 if (file_mode & S_IWOTH)
4433 dac_granted |= (VWRITE | VAPPEND);
4434 if ((accmode & dac_granted) == accmode)
4435 return (0);
4436
4437 privcheck:
4438 /*
4439 * Build a privilege mask to determine if the set of privileges
4440 * satisfies the requirements when combined with the granted mask
4441 * from above. For each privilege, if the privilege is required,
4442 * bitwise or the request type onto the priv_granted mask.
4443 */
4444 priv_granted = 0;
4445
4446 if (type == VDIR) {
4447 /*
4448 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
4449 * requests, instead of PRIV_VFS_EXEC.
4450 */
4451 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4452 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
4453 priv_granted |= VEXEC;
4454 } else {
4455 /*
4456 * Ensure that at least one execute bit is on. Otherwise,
4457 * a privileged user will always succeed, and we don't want
4458 * this to happen unless the file really is executable.
4459 */
4460 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4461 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
4462 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
4463 priv_granted |= VEXEC;
4464 }
4465
4466 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
4467 !priv_check_cred(cred, PRIV_VFS_READ, 0))
4468 priv_granted |= VREAD;
4469
4470 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
4471 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
4472 priv_granted |= (VWRITE | VAPPEND);
4473
4474 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
4475 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
4476 priv_granted |= VADMIN;
4477
4478 if ((accmode & (priv_granted | dac_granted)) == accmode) {
4479 /* XXX audit: privilege used */
4480 if (privused != NULL)
4481 *privused = 1;
4482 return (0);
4483 }
4484
4485 return ((accmode & VADMIN) ? EPERM : EACCES);
4486 }
4487
4488 /*
4489 * Credential check based on process requesting service, and per-attribute
4490 * permissions.
4491 */
4492 int
4493 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
4494 struct thread *td, accmode_t accmode)
4495 {
4496
4497 /*
4498 * Kernel-invoked always succeeds.
4499 */
4500 if (cred == NOCRED)
4501 return (0);
4502
4503 /*
4504 * Do not allow privileged processes in jail to directly manipulate
4505 * system attributes.
4506 */
4507 switch (attrnamespace) {
4508 case EXTATTR_NAMESPACE_SYSTEM:
4509 /* Potentially should be: return (EPERM); */
4510 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
4511 case EXTATTR_NAMESPACE_USER:
4512 return (VOP_ACCESS(vp, accmode, cred, td));
4513 default:
4514 return (EPERM);
4515 }
4516 }
4517
4518 #ifdef DEBUG_VFS_LOCKS
4519 /*
4520 * This only exists to suppress warnings from unlocked specfs accesses. It is
4521 * no longer ok to have an unlocked VFS.
4522 */
4523 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
4524 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
4525
4526 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
4527 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
4528 "Drop into debugger on lock violation");
4529
4530 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
4531 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
4532 0, "Check for interlock across VOPs");
4533
4534 int vfs_badlock_print = 1; /* Print lock violations. */
4535 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
4536 0, "Print lock violations");
4537
4538 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
4539 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
4540 0, "Print vnode details on lock violations");
4541
4542 #ifdef KDB
4543 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
4544 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
4545 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
4546 #endif
4547
4548 static void
4549 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
4550 {
4551
4552 #ifdef KDB
4553 if (vfs_badlock_backtrace)
4554 kdb_backtrace();
4555 #endif
4556 if (vfs_badlock_vnode)
4557 vn_printf(vp, "vnode ");
4558 if (vfs_badlock_print)
4559 printf("%s: %p %s\n", str, (void *)vp, msg);
4560 if (vfs_badlock_ddb)
4561 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4562 }
4563
4564 void
4565 assert_vi_locked(struct vnode *vp, const char *str)
4566 {
4567
4568 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
4569 vfs_badlock("interlock is not locked but should be", str, vp);
4570 }
4571
4572 void
4573 assert_vi_unlocked(struct vnode *vp, const char *str)
4574 {
4575
4576 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
4577 vfs_badlock("interlock is locked but should not be", str, vp);
4578 }
4579
4580 void
4581 assert_vop_locked(struct vnode *vp, const char *str)
4582 {
4583 int locked;
4584
4585 if (!IGNORE_LOCK(vp)) {
4586 locked = VOP_ISLOCKED(vp);
4587 if (locked == 0 || locked == LK_EXCLOTHER)
4588 vfs_badlock("is not locked but should be", str, vp);
4589 }
4590 }
4591
4592 void
4593 assert_vop_unlocked(struct vnode *vp, const char *str)
4594 {
4595
4596 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
4597 vfs_badlock("is locked but should not be", str, vp);
4598 }
4599
4600 void
4601 assert_vop_elocked(struct vnode *vp, const char *str)
4602 {
4603
4604 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
4605 vfs_badlock("is not exclusive locked but should be", str, vp);
4606 }
4607
4608 #if 0
4609 void
4610 assert_vop_elocked_other(struct vnode *vp, const char *str)
4611 {
4612
4613 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER)
4614 vfs_badlock("is not exclusive locked by another thread",
4615 str, vp);
4616 }
4617
4618 void
4619 assert_vop_slocked(struct vnode *vp, const char *str)
4620 {
4621
4622 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED)
4623 vfs_badlock("is not locked shared but should be", str, vp);
4624 }
4625 #endif /* 0 */
4626 #endif /* DEBUG_VFS_LOCKS */
4627
4628 void
4629 vop_rename_fail(struct vop_rename_args *ap)
4630 {
4631
4632 if (ap->a_tvp != NULL)
4633 vput(ap->a_tvp);
4634 if (ap->a_tdvp == ap->a_tvp)
4635 vrele(ap->a_tdvp);
4636 else
4637 vput(ap->a_tdvp);
4638 vrele(ap->a_fdvp);
4639 vrele(ap->a_fvp);
4640 }
4641
4642 void
4643 vop_rename_pre(void *ap)
4644 {
4645 struct vop_rename_args *a = ap;
4646
4647 #ifdef DEBUG_VFS_LOCKS
4648 if (a->a_tvp)
4649 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
4650 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
4651 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
4652 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
4653
4654 /* Check the source (from). */
4655 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
4656 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
4657 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
4658 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
4659 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
4660
4661 /* Check the target. */
4662 if (a->a_tvp)
4663 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
4664 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
4665 #endif
4666 if (a->a_tdvp != a->a_fdvp)
4667 vhold(a->a_fdvp);
4668 if (a->a_tvp != a->a_fvp)
4669 vhold(a->a_fvp);
4670 vhold(a->a_tdvp);
4671 if (a->a_tvp)
4672 vhold(a->a_tvp);
4673 }
4674
4675 #ifdef DEBUG_VFS_LOCKS
4676 void
4677 vop_strategy_pre(void *ap)
4678 {
4679 struct vop_strategy_args *a;
4680 struct buf *bp;
4681
4682 a = ap;
4683 bp = a->a_bp;
4684
4685 /*
4686 * Cluster ops lock their component buffers but not the IO container.
4687 */
4688 if ((bp->b_flags & B_CLUSTER) != 0)
4689 return;
4690
4691 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
4692 if (vfs_badlock_print)
4693 printf(
4694 "VOP_STRATEGY: bp is not locked but should be\n");
4695 if (vfs_badlock_ddb)
4696 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4697 }
4698 }
4699
4700 void
4701 vop_lock_pre(void *ap)
4702 {
4703 struct vop_lock1_args *a = ap;
4704
4705 if ((a->a_flags & LK_INTERLOCK) == 0)
4706 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4707 else
4708 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
4709 }
4710
4711 void
4712 vop_lock_post(void *ap, int rc)
4713 {
4714 struct vop_lock1_args *a = ap;
4715
4716 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4717 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
4718 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
4719 }
4720
4721 void
4722 vop_unlock_pre(void *ap)
4723 {
4724 struct vop_unlock_args *a = ap;
4725
4726 if (a->a_flags & LK_INTERLOCK)
4727 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
4728 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
4729 }
4730
4731 void
4732 vop_unlock_post(void *ap, int rc)
4733 {
4734 struct vop_unlock_args *a = ap;
4735
4736 if (a->a_flags & LK_INTERLOCK)
4737 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
4738 }
4739 #endif
4740
4741 void
4742 vop_create_post(void *ap, int rc)
4743 {
4744 struct vop_create_args *a = ap;
4745
4746 if (!rc)
4747 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4748 }
4749
4750 void
4751 vop_deleteextattr_post(void *ap, int rc)
4752 {
4753 struct vop_deleteextattr_args *a = ap;
4754
4755 if (!rc)
4756 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4757 }
4758
4759 void
4760 vop_link_post(void *ap, int rc)
4761 {
4762 struct vop_link_args *a = ap;
4763
4764 if (!rc) {
4765 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
4766 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
4767 }
4768 }
4769
4770 void
4771 vop_mkdir_post(void *ap, int rc)
4772 {
4773 struct vop_mkdir_args *a = ap;
4774
4775 if (!rc)
4776 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4777 }
4778
4779 void
4780 vop_mknod_post(void *ap, int rc)
4781 {
4782 struct vop_mknod_args *a = ap;
4783
4784 if (!rc)
4785 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4786 }
4787
4788 void
4789 vop_reclaim_post(void *ap, int rc)
4790 {
4791 struct vop_reclaim_args *a = ap;
4792
4793 if (!rc)
4794 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE);
4795 }
4796
4797 void
4798 vop_remove_post(void *ap, int rc)
4799 {
4800 struct vop_remove_args *a = ap;
4801
4802 if (!rc) {
4803 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4804 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4805 }
4806 }
4807
4808 void
4809 vop_rename_post(void *ap, int rc)
4810 {
4811 struct vop_rename_args *a = ap;
4812 long hint;
4813
4814 if (!rc) {
4815 hint = NOTE_WRITE;
4816 if (a->a_fdvp == a->a_tdvp) {
4817 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
4818 hint |= NOTE_LINK;
4819 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
4820 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
4821 } else {
4822 hint |= NOTE_EXTEND;
4823 if (a->a_fvp->v_type == VDIR)
4824 hint |= NOTE_LINK;
4825 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
4826
4827 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
4828 a->a_tvp->v_type == VDIR)
4829 hint &= ~NOTE_LINK;
4830 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
4831 }
4832
4833 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
4834 if (a->a_tvp)
4835 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
4836 }
4837 if (a->a_tdvp != a->a_fdvp)
4838 vdrop(a->a_fdvp);
4839 if (a->a_tvp != a->a_fvp)
4840 vdrop(a->a_fvp);
4841 vdrop(a->a_tdvp);
4842 if (a->a_tvp)
4843 vdrop(a->a_tvp);
4844 }
4845
4846 void
4847 vop_rmdir_post(void *ap, int rc)
4848 {
4849 struct vop_rmdir_args *a = ap;
4850
4851 if (!rc) {
4852 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4853 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4854 }
4855 }
4856
4857 void
4858 vop_setattr_post(void *ap, int rc)
4859 {
4860 struct vop_setattr_args *a = ap;
4861
4862 if (!rc)
4863 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4864 }
4865
4866 void
4867 vop_setextattr_post(void *ap, int rc)
4868 {
4869 struct vop_setextattr_args *a = ap;
4870
4871 if (!rc)
4872 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4873 }
4874
4875 void
4876 vop_symlink_post(void *ap, int rc)
4877 {
4878 struct vop_symlink_args *a = ap;
4879
4880 if (!rc)
4881 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4882 }
4883
4884 void
4885 vop_open_post(void *ap, int rc)
4886 {
4887 struct vop_open_args *a = ap;
4888
4889 if (!rc)
4890 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
4891 }
4892
4893 void
4894 vop_close_post(void *ap, int rc)
4895 {
4896 struct vop_close_args *a = ap;
4897
4898 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
4899 (a->a_vp->v_iflag & VI_DOOMED) == 0)) {
4900 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
4901 NOTE_CLOSE_WRITE : NOTE_CLOSE);
4902 }
4903 }
4904
4905 void
4906 vop_read_post(void *ap, int rc)
4907 {
4908 struct vop_read_args *a = ap;
4909
4910 if (!rc)
4911 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
4912 }
4913
4914 void
4915 vop_readdir_post(void *ap, int rc)
4916 {
4917 struct vop_readdir_args *a = ap;
4918
4919 if (!rc)
4920 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
4921 }
4922
4923 static struct knlist fs_knlist;
4924
4925 static void
4926 vfs_event_init(void *arg)
4927 {
4928 knlist_init_mtx(&fs_knlist, NULL);
4929 }
4930 /* XXX - correct order? */
4931 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
4932
4933 void
4934 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
4935 {
4936
4937 KNOTE_UNLOCKED(&fs_knlist, event);
4938 }
4939
4940 static int filt_fsattach(struct knote *kn);
4941 static void filt_fsdetach(struct knote *kn);
4942 static int filt_fsevent(struct knote *kn, long hint);
4943
4944 struct filterops fs_filtops = {
4945 .f_isfd = 0,
4946 .f_attach = filt_fsattach,
4947 .f_detach = filt_fsdetach,
4948 .f_event = filt_fsevent
4949 };
4950
4951 static int
4952 filt_fsattach(struct knote *kn)
4953 {
4954
4955 kn->kn_flags |= EV_CLEAR;
4956 knlist_add(&fs_knlist, kn, 0);
4957 return (0);
4958 }
4959
4960 static void
4961 filt_fsdetach(struct knote *kn)
4962 {
4963
4964 knlist_remove(&fs_knlist, kn, 0);
4965 }
4966
4967 static int
4968 filt_fsevent(struct knote *kn, long hint)
4969 {
4970
4971 kn->kn_fflags |= hint;
4972 return (kn->kn_fflags != 0);
4973 }
4974
4975 static int
4976 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
4977 {
4978 struct vfsidctl vc;
4979 int error;
4980 struct mount *mp;
4981
4982 error = SYSCTL_IN(req, &vc, sizeof(vc));
4983 if (error)
4984 return (error);
4985 if (vc.vc_vers != VFS_CTL_VERS1)
4986 return (EINVAL);
4987 mp = vfs_getvfs(&vc.vc_fsid);
4988 if (mp == NULL)
4989 return (ENOENT);
4990 /* ensure that a specific sysctl goes to the right filesystem. */
4991 if (strcmp(vc.vc_fstypename, "*") != 0 &&
4992 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
4993 vfs_rel(mp);
4994 return (EINVAL);
4995 }
4996 VCTLTOREQ(&vc, req);
4997 error = VFS_SYSCTL(mp, vc.vc_op, req);
4998 vfs_rel(mp);
4999 return (error);
5000 }
5001
5002 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
5003 NULL, 0, sysctl_vfs_ctl, "",
5004 "Sysctl by fsid");
5005
5006 /*
5007 * Function to initialize a va_filerev field sensibly.
5008 * XXX: Wouldn't a random number make a lot more sense ??
5009 */
5010 u_quad_t
5011 init_va_filerev(void)
5012 {
5013 struct bintime bt;
5014
5015 getbinuptime(&bt);
5016 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
5017 }
5018
5019 static int filt_vfsread(struct knote *kn, long hint);
5020 static int filt_vfswrite(struct knote *kn, long hint);
5021 static int filt_vfsvnode(struct knote *kn, long hint);
5022 static void filt_vfsdetach(struct knote *kn);
5023 static struct filterops vfsread_filtops = {
5024 .f_isfd = 1,
5025 .f_detach = filt_vfsdetach,
5026 .f_event = filt_vfsread
5027 };
5028 static struct filterops vfswrite_filtops = {
5029 .f_isfd = 1,
5030 .f_detach = filt_vfsdetach,
5031 .f_event = filt_vfswrite
5032 };
5033 static struct filterops vfsvnode_filtops = {
5034 .f_isfd = 1,
5035 .f_detach = filt_vfsdetach,
5036 .f_event = filt_vfsvnode
5037 };
5038
5039 static void
5040 vfs_knllock(void *arg)
5041 {
5042 struct vnode *vp = arg;
5043
5044 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5045 }
5046
5047 static void
5048 vfs_knlunlock(void *arg)
5049 {
5050 struct vnode *vp = arg;
5051
5052 VOP_UNLOCK(vp, 0);
5053 }
5054
5055 static void
5056 vfs_knl_assert_locked(void *arg)
5057 {
5058 #ifdef DEBUG_VFS_LOCKS
5059 struct vnode *vp = arg;
5060
5061 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
5062 #endif
5063 }
5064
5065 static void
5066 vfs_knl_assert_unlocked(void *arg)
5067 {
5068 #ifdef DEBUG_VFS_LOCKS
5069 struct vnode *vp = arg;
5070
5071 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
5072 #endif
5073 }
5074
5075 int
5076 vfs_kqfilter(struct vop_kqfilter_args *ap)
5077 {
5078 struct vnode *vp = ap->a_vp;
5079 struct knote *kn = ap->a_kn;
5080 struct knlist *knl;
5081
5082 switch (kn->kn_filter) {
5083 case EVFILT_READ:
5084 kn->kn_fop = &vfsread_filtops;
5085 break;
5086 case EVFILT_WRITE:
5087 kn->kn_fop = &vfswrite_filtops;
5088 break;
5089 case EVFILT_VNODE:
5090 kn->kn_fop = &vfsvnode_filtops;
5091 break;
5092 default:
5093 return (EINVAL);
5094 }
5095
5096 kn->kn_hook = (caddr_t)vp;
5097
5098 v_addpollinfo(vp);
5099 if (vp->v_pollinfo == NULL)
5100 return (ENOMEM);
5101 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
5102 vhold(vp);
5103 knlist_add(knl, kn, 0);
5104
5105 return (0);
5106 }
5107
5108 /*
5109 * Detach knote from vnode
5110 */
5111 static void
5112 filt_vfsdetach(struct knote *kn)
5113 {
5114 struct vnode *vp = (struct vnode *)kn->kn_hook;
5115
5116 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
5117 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
5118 vdrop(vp);
5119 }
5120
5121 /*ARGSUSED*/
5122 static int
5123 filt_vfsread(struct knote *kn, long hint)
5124 {
5125 struct vnode *vp = (struct vnode *)kn->kn_hook;
5126 struct vattr va;
5127 int res;
5128
5129 /*
5130 * filesystem is gone, so set the EOF flag and schedule
5131 * the knote for deletion.
5132 */
5133 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
5134 VI_LOCK(vp);
5135 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
5136 VI_UNLOCK(vp);
5137 return (1);
5138 }
5139
5140 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
5141 return (0);
5142
5143 VI_LOCK(vp);
5144 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
5145 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
5146 VI_UNLOCK(vp);
5147 return (res);
5148 }
5149
5150 /*ARGSUSED*/
5151 static int
5152 filt_vfswrite(struct knote *kn, long hint)
5153 {
5154 struct vnode *vp = (struct vnode *)kn->kn_hook;
5155
5156 VI_LOCK(vp);
5157
5158 /*
5159 * filesystem is gone, so set the EOF flag and schedule
5160 * the knote for deletion.
5161 */
5162 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
5163 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
5164
5165 kn->kn_data = 0;
5166 VI_UNLOCK(vp);
5167 return (1);
5168 }
5169
5170 static int
5171 filt_vfsvnode(struct knote *kn, long hint)
5172 {
5173 struct vnode *vp = (struct vnode *)kn->kn_hook;
5174 int res;
5175
5176 VI_LOCK(vp);
5177 if (kn->kn_sfflags & hint)
5178 kn->kn_fflags |= hint;
5179 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
5180 kn->kn_flags |= EV_EOF;
5181 VI_UNLOCK(vp);
5182 return (1);
5183 }
5184 res = (kn->kn_fflags != 0);
5185 VI_UNLOCK(vp);
5186 return (res);
5187 }
5188
5189 int
5190 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
5191 {
5192 int error;
5193
5194 if (dp->d_reclen > ap->a_uio->uio_resid)
5195 return (ENAMETOOLONG);
5196 error = uiomove(dp, dp->d_reclen, ap->a_uio);
5197 if (error) {
5198 if (ap->a_ncookies != NULL) {
5199 if (ap->a_cookies != NULL)
5200 free(ap->a_cookies, M_TEMP);
5201 ap->a_cookies = NULL;
5202 *ap->a_ncookies = 0;
5203 }
5204 return (error);
5205 }
5206 if (ap->a_ncookies == NULL)
5207 return (0);
5208
5209 KASSERT(ap->a_cookies,
5210 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
5211
5212 *ap->a_cookies = realloc(*ap->a_cookies,
5213 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
5214 (*ap->a_cookies)[*ap->a_ncookies] = off;
5215 *ap->a_ncookies += 1;
5216 return (0);
5217 }
5218
5219 /*
5220 * Mark for update the access time of the file if the filesystem
5221 * supports VOP_MARKATIME. This functionality is used by execve and
5222 * mmap, so we want to avoid the I/O implied by directly setting
5223 * va_atime for the sake of efficiency.
5224 */
5225 void
5226 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
5227 {
5228 struct mount *mp;
5229
5230 mp = vp->v_mount;
5231 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
5232 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
5233 (void)VOP_MARKATIME(vp);
5234 }
5235
5236 /*
5237 * The purpose of this routine is to remove granularity from accmode_t,
5238 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
5239 * VADMIN and VAPPEND.
5240 *
5241 * If it returns 0, the caller is supposed to continue with the usual
5242 * access checks using 'accmode' as modified by this routine. If it
5243 * returns nonzero value, the caller is supposed to return that value
5244 * as errno.
5245 *
5246 * Note that after this routine runs, accmode may be zero.
5247 */
5248 int
5249 vfs_unixify_accmode(accmode_t *accmode)
5250 {
5251 /*
5252 * There is no way to specify explicit "deny" rule using
5253 * file mode or POSIX.1e ACLs.
5254 */
5255 if (*accmode & VEXPLICIT_DENY) {
5256 *accmode = 0;
5257 return (0);
5258 }
5259
5260 /*
5261 * None of these can be translated into usual access bits.
5262 * Also, the common case for NFSv4 ACLs is to not contain
5263 * either of these bits. Caller should check for VWRITE
5264 * on the containing directory instead.
5265 */
5266 if (*accmode & (VDELETE_CHILD | VDELETE))
5267 return (EPERM);
5268
5269 if (*accmode & VADMIN_PERMS) {
5270 *accmode &= ~VADMIN_PERMS;
5271 *accmode |= VADMIN;
5272 }
5273
5274 /*
5275 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
5276 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
5277 */
5278 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
5279
5280 return (0);
5281 }
5282
5283 /*
5284 * These are helper functions for filesystems to traverse all
5285 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
5286 *
5287 * This interface replaces MNT_VNODE_FOREACH.
5288 */
5289
5290 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
5291
5292 struct vnode *
5293 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
5294 {
5295 struct vnode *vp;
5296
5297 if (should_yield())
5298 kern_yield(PRI_USER);
5299 MNT_ILOCK(mp);
5300 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5301 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL;
5302 vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
5303 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */
5304 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0)
5305 continue;
5306 VI_LOCK(vp);
5307 if ((vp->v_iflag & VI_DOOMED) != 0) {
5308 VI_UNLOCK(vp);
5309 continue;
5310 }
5311 break;
5312 }
5313 if (vp == NULL) {
5314 __mnt_vnode_markerfree_all(mvp, mp);
5315 /* MNT_IUNLOCK(mp); -- done in above function */
5316 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
5317 return (NULL);
5318 }
5319 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5320 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5321 MNT_IUNLOCK(mp);
5322 return (vp);
5323 }
5324
5325 struct vnode *
5326 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
5327 {
5328 struct vnode *vp;
5329
5330 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
5331 MNT_ILOCK(mp);
5332 MNT_REF(mp);
5333 (*mvp)->v_mount = mp;
5334 (*mvp)->v_type = VMARKER;
5335
5336 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
5337 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */
5338 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0)
5339 continue;
5340 VI_LOCK(vp);
5341 if ((vp->v_iflag & VI_DOOMED) != 0) {
5342 VI_UNLOCK(vp);
5343 continue;
5344 }
5345 break;
5346 }
5347 if (vp == NULL) {
5348 MNT_REL(mp);
5349 MNT_IUNLOCK(mp);
5350 free(*mvp, M_VNODE_MARKER);
5351 *mvp = NULL;
5352 return (NULL);
5353 }
5354 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5355 MNT_IUNLOCK(mp);
5356 return (vp);
5357 }
5358
5359 void
5360 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
5361 {
5362
5363 if (*mvp == NULL) {
5364 MNT_IUNLOCK(mp);
5365 return;
5366 }
5367
5368 mtx_assert(MNT_MTX(mp), MA_OWNED);
5369
5370 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5371 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5372 MNT_REL(mp);
5373 MNT_IUNLOCK(mp);
5374 free(*mvp, M_VNODE_MARKER);
5375 *mvp = NULL;
5376 }
5377
5378 /*
5379 * These are helper functions for filesystems to traverse their
5380 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
5381 */
5382 static void
5383 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
5384 {
5385
5386 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5387
5388 MNT_ILOCK(mp);
5389 MNT_REL(mp);
5390 MNT_IUNLOCK(mp);
5391 free(*mvp, M_VNODE_MARKER);
5392 *mvp = NULL;
5393 }
5394
5395 static struct vnode *
5396 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
5397 {
5398 struct vnode *vp, *nvp;
5399
5400 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
5401 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5402 restart:
5403 vp = TAILQ_NEXT(*mvp, v_actfreelist);
5404 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
5405 while (vp != NULL) {
5406 if (vp->v_type == VMARKER) {
5407 vp = TAILQ_NEXT(vp, v_actfreelist);
5408 continue;
5409 }
5410 if (!VI_TRYLOCK(vp)) {
5411 if (mp_ncpus == 1 || should_yield()) {
5412 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
5413 mtx_unlock(&vnode_free_list_mtx);
5414 pause("vnacti", 1);
5415 mtx_lock(&vnode_free_list_mtx);
5416 goto restart;
5417 }
5418 continue;
5419 }
5420 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
5421 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
5422 ("alien vnode on the active list %p %p", vp, mp));
5423 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0)
5424 break;
5425 nvp = TAILQ_NEXT(vp, v_actfreelist);
5426 VI_UNLOCK(vp);
5427 vp = nvp;
5428 }
5429
5430 /* Check if we are done */
5431 if (vp == NULL) {
5432 mtx_unlock(&vnode_free_list_mtx);
5433 mnt_vnode_markerfree_active(mvp, mp);
5434 return (NULL);
5435 }
5436 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
5437 mtx_unlock(&vnode_free_list_mtx);
5438 ASSERT_VI_LOCKED(vp, "active iter");
5439 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp));
5440 return (vp);
5441 }
5442
5443 struct vnode *
5444 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
5445 {
5446
5447 if (should_yield())
5448 kern_yield(PRI_USER);
5449 mtx_lock(&vnode_free_list_mtx);
5450 return (mnt_vnode_next_active(mvp, mp));
5451 }
5452
5453 struct vnode *
5454 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
5455 {
5456 struct vnode *vp;
5457
5458 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
5459 MNT_ILOCK(mp);
5460 MNT_REF(mp);
5461 MNT_IUNLOCK(mp);
5462 (*mvp)->v_type = VMARKER;
5463 (*mvp)->v_mount = mp;
5464
5465 mtx_lock(&vnode_free_list_mtx);
5466 vp = TAILQ_FIRST(&mp->mnt_activevnodelist);
5467 if (vp == NULL) {
5468 mtx_unlock(&vnode_free_list_mtx);
5469 mnt_vnode_markerfree_active(mvp, mp);
5470 return (NULL);
5471 }
5472 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
5473 return (mnt_vnode_next_active(mvp, mp));
5474 }
5475
5476 void
5477 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
5478 {
5479
5480 if (*mvp == NULL)
5481 return;
5482
5483 mtx_lock(&vnode_free_list_mtx);
5484 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
5485 mtx_unlock(&vnode_free_list_mtx);
5486 mnt_vnode_markerfree_active(mvp, mp);
5487 }
5488
5489 int
5490 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp)
5491 {
5492
5493 if ((cnp->cn_flags & NOEXECCHECK) != 0) {
5494 cnp->cn_flags &= ~NOEXECCHECK;
5495 return (0);
5496 }
5497
5498 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread));
5499 }
Cache object: 20ea2658bf45a8ca481a8718eda5147e
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