1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 /*
38 * External virtual filesystem routines
39 */
40
41 #include <sys/cdefs.h>
42 #include "opt_ddb.h"
43 #include "opt_watchdog.h"
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/asan.h>
48 #include <sys/bio.h>
49 #include <sys/buf.h>
50 #include <sys/capsicum.h>
51 #include <sys/condvar.h>
52 #include <sys/conf.h>
53 #include <sys/counter.h>
54 #include <sys/dirent.h>
55 #include <sys/event.h>
56 #include <sys/eventhandler.h>
57 #include <sys/extattr.h>
58 #include <sys/file.h>
59 #include <sys/fcntl.h>
60 #include <sys/jail.h>
61 #include <sys/kdb.h>
62 #include <sys/kernel.h>
63 #include <sys/kthread.h>
64 #include <sys/ktr.h>
65 #include <sys/limits.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/smr.h>
78 #include <sys/smp.h>
79 #include <sys/stat.h>
80 #include <sys/sysctl.h>
81 #include <sys/syslog.h>
82 #include <sys/vmmeter.h>
83 #include <sys/vnode.h>
84 #include <sys/watchdog.h>
85
86 #include <machine/stdarg.h>
87
88 #include <security/mac/mac_framework.h>
89
90 #include <vm/vm.h>
91 #include <vm/vm_object.h>
92 #include <vm/vm_extern.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_map.h>
95 #include <vm/vm_page.h>
96 #include <vm/vm_kern.h>
97 #include <vm/vnode_pager.h>
98 #include <vm/uma.h>
99
100 #if defined(DEBUG_VFS_LOCKS) && (!defined(INVARIANTS) || !defined(WITNESS))
101 #error DEBUG_VFS_LOCKS requires INVARIANTS and WITNESS
102 #endif
103
104 #ifdef DDB
105 #include <ddb/ddb.h>
106 #endif
107
108 static void delmntque(struct vnode *vp);
109 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
110 int slpflag, int slptimeo);
111 static void syncer_shutdown(void *arg, int howto);
112 static int vtryrecycle(struct vnode *vp, bool isvnlru);
113 static void v_init_counters(struct vnode *);
114 static void vn_seqc_init(struct vnode *);
115 static void vn_seqc_write_end_free(struct vnode *vp);
116 static void vgonel(struct vnode *);
117 static bool vhold_recycle_free(struct vnode *);
118 static void vdropl_recycle(struct vnode *vp);
119 static void vdrop_recycle(struct vnode *vp);
120 static void vfs_knllock(void *arg);
121 static void vfs_knlunlock(void *arg);
122 static void vfs_knl_assert_lock(void *arg, int what);
123 static void destroy_vpollinfo(struct vpollinfo *vi);
124 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
125 daddr_t startlbn, daddr_t endlbn);
126 static void vnlru_recalc(void);
127
128 static SYSCTL_NODE(_vfs, OID_AUTO, vnode, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
129 "vnode configuration and statistics");
130 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, param, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
131 "vnode configuration");
132 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
133 "vnode statistics");
134 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, vnlru, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
135 "vnode recycling");
136
137 /*
138 * Number of vnodes in existence. Increased whenever getnewvnode()
139 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode.
140 */
141 static u_long __exclusive_cache_line numvnodes;
142
143 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
144 "Number of vnodes in existence (legacy)");
145 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, count, CTLFLAG_RD, &numvnodes, 0,
146 "Number of vnodes in existence");
147
148 static counter_u64_t vnodes_created;
149 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
150 "Number of vnodes created by getnewvnode (legacy)");
151 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, created, CTLFLAG_RD, &vnodes_created,
152 "Number of vnodes created by getnewvnode");
153
154 /*
155 * Conversion tables for conversion from vnode types to inode formats
156 * and back.
157 */
158 __enum_uint8(vtype) iftovt_tab[16] = {
159 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
160 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
161 };
162 int vttoif_tab[10] = {
163 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
164 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
165 };
166
167 /*
168 * List of allocates vnodes in the system.
169 */
170 static TAILQ_HEAD(freelst, vnode) vnode_list;
171 static struct vnode *vnode_list_free_marker;
172 static struct vnode *vnode_list_reclaim_marker;
173
174 /*
175 * "Free" vnode target. Free vnodes are rarely completely free, but are
176 * just ones that are cheap to recycle. Usually they are for files which
177 * have been stat'd but not read; these usually have inode and namecache
178 * data attached to them. This target is the preferred minimum size of a
179 * sub-cache consisting mostly of such files. The system balances the size
180 * of this sub-cache with its complement to try to prevent either from
181 * thrashing while the other is relatively inactive. The targets express
182 * a preference for the best balance.
183 *
184 * "Above" this target there are 2 further targets (watermarks) related
185 * to recyling of free vnodes. In the best-operating case, the cache is
186 * exactly full, the free list has size between vlowat and vhiwat above the
187 * free target, and recycling from it and normal use maintains this state.
188 * Sometimes the free list is below vlowat or even empty, but this state
189 * is even better for immediate use provided the cache is not full.
190 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
191 * ones) to reach one of these states. The watermarks are currently hard-
192 * coded as 4% and 9% of the available space higher. These and the default
193 * of 25% for wantfreevnodes are too large if the memory size is large.
194 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
195 * whenever vnlru_proc() becomes active.
196 */
197 static long wantfreevnodes;
198 static long __exclusive_cache_line freevnodes;
199 static long freevnodes_old;
200
201 static u_long recycles_count;
202 SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS, &recycles_count, 0,
203 "Number of vnodes recycled to meet vnode cache targets (legacy)");
204 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS,
205 &recycles_count, 0,
206 "Number of vnodes recycled to meet vnode cache targets");
207
208 static u_long recycles_free_count;
209 SYSCTL_ULONG(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS,
210 &recycles_free_count, 0,
211 "Number of free vnodes recycled to meet vnode cache targets (legacy)");
212 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS,
213 &recycles_free_count, 0,
214 "Number of free vnodes recycled to meet vnode cache targets");
215
216 static counter_u64_t direct_recycles_free_count;
217 SYSCTL_COUNTER_U64(_vfs_vnode_vnlru, OID_AUTO, direct_recycles_free, CTLFLAG_RD,
218 &direct_recycles_free_count,
219 "Number of free vnodes recycled by vn_alloc callers to meet vnode cache targets");
220
221 static counter_u64_t vnode_skipped_requeues;
222 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, skipped_requeues, CTLFLAG_RD, &vnode_skipped_requeues,
223 "Number of times LRU requeue was skipped due to lock contention");
224
225 static u_long deferred_inact;
226 SYSCTL_ULONG(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD,
227 &deferred_inact, 0, "Number of times inactive processing was deferred");
228
229 /* To keep more than one thread at a time from running vfs_getnewfsid */
230 static struct mtx mntid_mtx;
231
232 /*
233 * Lock for any access to the following:
234 * vnode_list
235 * numvnodes
236 * freevnodes
237 */
238 static struct mtx __exclusive_cache_line vnode_list_mtx;
239
240 /* Publicly exported FS */
241 struct nfs_public nfs_pub;
242
243 static uma_zone_t buf_trie_zone;
244 static smr_t buf_trie_smr;
245
246 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
247 static uma_zone_t vnode_zone;
248 MALLOC_DEFINE(M_VNODEPOLL, "VN POLL", "vnode poll");
249
250 __read_frequently smr_t vfs_smr;
251
252 /*
253 * The workitem queue.
254 *
255 * It is useful to delay writes of file data and filesystem metadata
256 * for tens of seconds so that quickly created and deleted files need
257 * not waste disk bandwidth being created and removed. To realize this,
258 * we append vnodes to a "workitem" queue. When running with a soft
259 * updates implementation, most pending metadata dependencies should
260 * not wait for more than a few seconds. Thus, mounted on block devices
261 * are delayed only about a half the time that file data is delayed.
262 * Similarly, directory updates are more critical, so are only delayed
263 * about a third the time that file data is delayed. Thus, there are
264 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
265 * one each second (driven off the filesystem syncer process). The
266 * syncer_delayno variable indicates the next queue that is to be processed.
267 * Items that need to be processed soon are placed in this queue:
268 *
269 * syncer_workitem_pending[syncer_delayno]
270 *
271 * A delay of fifteen seconds is done by placing the request fifteen
272 * entries later in the queue:
273 *
274 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
275 *
276 */
277 static int syncer_delayno;
278 static long syncer_mask;
279 LIST_HEAD(synclist, bufobj);
280 static struct synclist *syncer_workitem_pending;
281 /*
282 * The sync_mtx protects:
283 * bo->bo_synclist
284 * sync_vnode_count
285 * syncer_delayno
286 * syncer_state
287 * syncer_workitem_pending
288 * syncer_worklist_len
289 * rushjob
290 */
291 static struct mtx sync_mtx;
292 static struct cv sync_wakeup;
293
294 #define SYNCER_MAXDELAY 32
295 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
296 static int syncdelay = 30; /* max time to delay syncing data */
297 static int filedelay = 30; /* time to delay syncing files */
298 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
299 "Time to delay syncing files (in seconds)");
300 static int dirdelay = 29; /* time to delay syncing directories */
301 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
302 "Time to delay syncing directories (in seconds)");
303 static int metadelay = 28; /* time to delay syncing metadata */
304 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
305 "Time to delay syncing metadata (in seconds)");
306 static int rushjob; /* number of slots to run ASAP */
307 static int stat_rush_requests; /* number of times I/O speeded up */
308 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
309 "Number of times I/O speeded up (rush requests)");
310
311 #define VDBATCH_SIZE 8
312 struct vdbatch {
313 u_int index;
314 struct mtx lock;
315 struct vnode *tab[VDBATCH_SIZE];
316 };
317 DPCPU_DEFINE_STATIC(struct vdbatch, vd);
318
319 static void vdbatch_dequeue(struct vnode *vp);
320
321 /*
322 * When shutting down the syncer, run it at four times normal speed.
323 */
324 #define SYNCER_SHUTDOWN_SPEEDUP 4
325 static int sync_vnode_count;
326 static int syncer_worklist_len;
327 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
328 syncer_state;
329
330 /* Target for maximum number of vnodes. */
331 u_long desiredvnodes;
332 static u_long gapvnodes; /* gap between wanted and desired */
333 static u_long vhiwat; /* enough extras after expansion */
334 static u_long vlowat; /* minimal extras before expansion */
335 static bool vstir; /* nonzero to stir non-free vnodes */
336 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
337
338 static u_long vnlru_read_freevnodes(void);
339
340 /*
341 * Note that no attempt is made to sanitize these parameters.
342 */
343 static int
sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)344 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)
345 {
346 u_long val;
347 int error;
348
349 val = desiredvnodes;
350 error = sysctl_handle_long(oidp, &val, 0, req);
351 if (error != 0 || req->newptr == NULL)
352 return (error);
353
354 if (val == desiredvnodes)
355 return (0);
356 mtx_lock(&vnode_list_mtx);
357 desiredvnodes = val;
358 wantfreevnodes = desiredvnodes / 4;
359 vnlru_recalc();
360 mtx_unlock(&vnode_list_mtx);
361 /*
362 * XXX There is no protection against multiple threads changing
363 * desiredvnodes at the same time. Locking above only helps vnlru and
364 * getnewvnode.
365 */
366 vfs_hash_changesize(desiredvnodes);
367 cache_changesize(desiredvnodes);
368 return (0);
369 }
370
371 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
372 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
373 "LU", "Target for maximum number of vnodes (legacy)");
374 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, limit,
375 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
376 "LU", "Target for maximum number of vnodes");
377
378 static int
sysctl_freevnodes(SYSCTL_HANDLER_ARGS)379 sysctl_freevnodes(SYSCTL_HANDLER_ARGS)
380 {
381 u_long rfreevnodes;
382
383 rfreevnodes = vnlru_read_freevnodes();
384 return (sysctl_handle_long(oidp, &rfreevnodes, 0, req));
385 }
386
387 SYSCTL_PROC(_vfs, OID_AUTO, freevnodes,
388 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
389 "LU", "Number of \"free\" vnodes (legacy)");
390 SYSCTL_PROC(_vfs_vnode_stats, OID_AUTO, free,
391 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
392 "LU", "Number of \"free\" vnodes");
393
394 static int
sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)395 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)
396 {
397 u_long val;
398 int error;
399
400 val = wantfreevnodes;
401 error = sysctl_handle_long(oidp, &val, 0, req);
402 if (error != 0 || req->newptr == NULL)
403 return (error);
404
405 if (val == wantfreevnodes)
406 return (0);
407 mtx_lock(&vnode_list_mtx);
408 wantfreevnodes = val;
409 vnlru_recalc();
410 mtx_unlock(&vnode_list_mtx);
411 return (0);
412 }
413
414 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes,
415 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
416 "LU", "Target for minimum number of \"free\" vnodes (legacy)");
417 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, wantfree,
418 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
419 "LU", "Target for minimum number of \"free\" vnodes");
420
421 static int vnlru_nowhere;
422 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, failed_runs, CTLFLAG_RD | CTLFLAG_STATS,
423 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
424
425 static int
sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)426 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
427 {
428 struct vnode *vp;
429 struct nameidata nd;
430 char *buf;
431 unsigned long ndflags;
432 int error;
433
434 if (req->newptr == NULL)
435 return (EINVAL);
436 if (req->newlen >= PATH_MAX)
437 return (E2BIG);
438
439 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK);
440 error = SYSCTL_IN(req, buf, req->newlen);
441 if (error != 0)
442 goto out;
443
444 buf[req->newlen] = '\0';
445
446 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1;
447 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf);
448 if ((error = namei(&nd)) != 0)
449 goto out;
450 vp = nd.ni_vp;
451
452 if (VN_IS_DOOMED(vp)) {
453 /*
454 * This vnode is being recycled. Return != 0 to let the caller
455 * know that the sysctl had no effect. Return EAGAIN because a
456 * subsequent call will likely succeed (since namei will create
457 * a new vnode if necessary)
458 */
459 error = EAGAIN;
460 goto putvnode;
461 }
462
463 vgone(vp);
464 putvnode:
465 vput(vp);
466 NDFREE_PNBUF(&nd);
467 out:
468 free(buf, M_TEMP);
469 return (error);
470 }
471
472 static int
sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)473 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)
474 {
475 struct thread *td = curthread;
476 struct vnode *vp;
477 struct file *fp;
478 int error;
479 int fd;
480
481 if (req->newptr == NULL)
482 return (EBADF);
483
484 error = sysctl_handle_int(oidp, &fd, 0, req);
485 if (error != 0)
486 return (error);
487 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp);
488 if (error != 0)
489 return (error);
490 vp = fp->f_vnode;
491
492 error = vn_lock(vp, LK_EXCLUSIVE);
493 if (error != 0)
494 goto drop;
495
496 vgone(vp);
497 VOP_UNLOCK(vp);
498 drop:
499 fdrop(fp, td);
500 return (error);
501 }
502
503 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
504 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
505 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
506 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode,
507 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
508 sysctl_ftry_reclaim_vnode, "I",
509 "Try to reclaim a vnode by its file descriptor");
510
511 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
512 #define vnsz2log 8
513 #ifndef DEBUG_LOCKS
514 _Static_assert(sizeof(struct vnode) >= 1UL << vnsz2log &&
515 sizeof(struct vnode) < 1UL << (vnsz2log + 1),
516 "vnsz2log needs to be updated");
517 #endif
518
519 /*
520 * Support for the bufobj clean & dirty pctrie.
521 */
522 static void *
buf_trie_alloc(struct pctrie * ptree)523 buf_trie_alloc(struct pctrie *ptree)
524 {
525 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT));
526 }
527
528 static void
buf_trie_free(struct pctrie * ptree,void * node)529 buf_trie_free(struct pctrie *ptree, void *node)
530 {
531 uma_zfree_smr(buf_trie_zone, node);
532 }
533 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free,
534 buf_trie_smr);
535
536 /*
537 * Initialize the vnode management data structures.
538 *
539 * Reevaluate the following cap on the number of vnodes after the physical
540 * memory size exceeds 512GB. In the limit, as the physical memory size
541 * grows, the ratio of the memory size in KB to vnodes approaches 64:1.
542 */
543 #ifndef MAXVNODES_MAX
544 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */
545 #endif
546
547 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
548
549 static struct vnode *
vn_alloc_marker(struct mount * mp)550 vn_alloc_marker(struct mount *mp)
551 {
552 struct vnode *vp;
553
554 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
555 vp->v_type = VMARKER;
556 vp->v_mount = mp;
557
558 return (vp);
559 }
560
561 static void
vn_free_marker(struct vnode * vp)562 vn_free_marker(struct vnode *vp)
563 {
564
565 MPASS(vp->v_type == VMARKER);
566 free(vp, M_VNODE_MARKER);
567 }
568
569 #ifdef KASAN
570 static int
vnode_ctor(void * mem,int size,void * arg __unused,int flags __unused)571 vnode_ctor(void *mem, int size, void *arg __unused, int flags __unused)
572 {
573 kasan_mark(mem, size, roundup2(size, UMA_ALIGN_PTR + 1), 0);
574 return (0);
575 }
576
577 static void
vnode_dtor(void * mem,int size,void * arg __unused)578 vnode_dtor(void *mem, int size, void *arg __unused)
579 {
580 size_t end1, end2, off1, off2;
581
582 _Static_assert(offsetof(struct vnode, v_vnodelist) <
583 offsetof(struct vnode, v_dbatchcpu),
584 "KASAN marks require updating");
585
586 off1 = offsetof(struct vnode, v_vnodelist);
587 off2 = offsetof(struct vnode, v_dbatchcpu);
588 end1 = off1 + sizeof(((struct vnode *)NULL)->v_vnodelist);
589 end2 = off2 + sizeof(((struct vnode *)NULL)->v_dbatchcpu);
590
591 /*
592 * Access to the v_vnodelist and v_dbatchcpu fields are permitted even
593 * after the vnode has been freed. Try to get some KASAN coverage by
594 * marking everything except those two fields as invalid. Because
595 * KASAN's tracking is not byte-granular, any preceding fields sharing
596 * the same 8-byte aligned word must also be marked valid.
597 */
598
599 /* Handle the area from the start until v_vnodelist... */
600 off1 = rounddown2(off1, KASAN_SHADOW_SCALE);
601 kasan_mark(mem, off1, off1, KASAN_UMA_FREED);
602
603 /* ... then the area between v_vnodelist and v_dbatchcpu ... */
604 off1 = roundup2(end1, KASAN_SHADOW_SCALE);
605 off2 = rounddown2(off2, KASAN_SHADOW_SCALE);
606 if (off2 > off1)
607 kasan_mark((void *)((char *)mem + off1), off2 - off1,
608 off2 - off1, KASAN_UMA_FREED);
609
610 /* ... and finally the area from v_dbatchcpu to the end. */
611 off2 = roundup2(end2, KASAN_SHADOW_SCALE);
612 kasan_mark((void *)((char *)mem + off2), size - off2, size - off2,
613 KASAN_UMA_FREED);
614 }
615 #endif /* KASAN */
616
617 /*
618 * Initialize a vnode as it first enters the zone.
619 */
620 static int
vnode_init(void * mem,int size,int flags)621 vnode_init(void *mem, int size, int flags)
622 {
623 struct vnode *vp;
624
625 vp = mem;
626 bzero(vp, size);
627 /*
628 * Setup locks.
629 */
630 vp->v_vnlock = &vp->v_lock;
631 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
632 /*
633 * By default, don't allow shared locks unless filesystems opt-in.
634 */
635 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
636 LK_NOSHARE | LK_IS_VNODE);
637 /*
638 * Initialize bufobj.
639 */
640 bufobj_init(&vp->v_bufobj, vp);
641 /*
642 * Initialize namecache.
643 */
644 cache_vnode_init(vp);
645 /*
646 * Initialize rangelocks.
647 */
648 rangelock_init(&vp->v_rl);
649
650 vp->v_dbatchcpu = NOCPU;
651
652 vp->v_state = VSTATE_DEAD;
653
654 /*
655 * Check vhold_recycle_free for an explanation.
656 */
657 vp->v_holdcnt = VHOLD_NO_SMR;
658 vp->v_type = VNON;
659 mtx_lock(&vnode_list_mtx);
660 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist);
661 mtx_unlock(&vnode_list_mtx);
662 return (0);
663 }
664
665 /*
666 * Free a vnode when it is cleared from the zone.
667 */
668 static void
vnode_fini(void * mem,int size)669 vnode_fini(void *mem, int size)
670 {
671 struct vnode *vp;
672 struct bufobj *bo;
673
674 vp = mem;
675 vdbatch_dequeue(vp);
676 mtx_lock(&vnode_list_mtx);
677 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
678 mtx_unlock(&vnode_list_mtx);
679 rangelock_destroy(&vp->v_rl);
680 lockdestroy(vp->v_vnlock);
681 mtx_destroy(&vp->v_interlock);
682 bo = &vp->v_bufobj;
683 rw_destroy(BO_LOCKPTR(bo));
684
685 kasan_mark(mem, size, size, 0);
686 }
687
688 /*
689 * Provide the size of NFS nclnode and NFS fh for calculation of the
690 * vnode memory consumption. The size is specified directly to
691 * eliminate dependency on NFS-private header.
692 *
693 * Other filesystems may use bigger or smaller (like UFS and ZFS)
694 * private inode data, but the NFS-based estimation is ample enough.
695 * Still, we care about differences in the size between 64- and 32-bit
696 * platforms.
697 *
698 * Namecache structure size is heuristically
699 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
700 */
701 #ifdef _LP64
702 #define NFS_NCLNODE_SZ (528 + 64)
703 #define NC_SZ 148
704 #else
705 #define NFS_NCLNODE_SZ (360 + 32)
706 #define NC_SZ 92
707 #endif
708
709 static void
vntblinit(void * dummy __unused)710 vntblinit(void *dummy __unused)
711 {
712 struct vdbatch *vd;
713 uma_ctor ctor;
714 uma_dtor dtor;
715 int cpu, physvnodes, virtvnodes;
716
717 /*
718 * Desiredvnodes is a function of the physical memory size and the
719 * kernel's heap size. Generally speaking, it scales with the
720 * physical memory size. The ratio of desiredvnodes to the physical
721 * memory size is 1:16 until desiredvnodes exceeds 98,304.
722 * Thereafter, the
723 * marginal ratio of desiredvnodes to the physical memory size is
724 * 1:64. However, desiredvnodes is limited by the kernel's heap
725 * size. The memory required by desiredvnodes vnodes and vm objects
726 * must not exceed 1/10th of the kernel's heap size.
727 */
728 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
729 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
730 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
731 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
732 desiredvnodes = min(physvnodes, virtvnodes);
733 if (desiredvnodes > MAXVNODES_MAX) {
734 if (bootverbose)
735 printf("Reducing kern.maxvnodes %lu -> %lu\n",
736 desiredvnodes, MAXVNODES_MAX);
737 desiredvnodes = MAXVNODES_MAX;
738 }
739 wantfreevnodes = desiredvnodes / 4;
740 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
741 TAILQ_INIT(&vnode_list);
742 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF);
743 /*
744 * The lock is taken to appease WITNESS.
745 */
746 mtx_lock(&vnode_list_mtx);
747 vnlru_recalc();
748 mtx_unlock(&vnode_list_mtx);
749 vnode_list_free_marker = vn_alloc_marker(NULL);
750 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist);
751 vnode_list_reclaim_marker = vn_alloc_marker(NULL);
752 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist);
753
754 #ifdef KASAN
755 ctor = vnode_ctor;
756 dtor = vnode_dtor;
757 #else
758 ctor = NULL;
759 dtor = NULL;
760 #endif
761 vnode_zone = uma_zcreate("VNODE", sizeof(struct vnode), ctor, dtor,
762 vnode_init, vnode_fini, UMA_ALIGN_PTR, UMA_ZONE_NOKASAN);
763 uma_zone_set_smr(vnode_zone, vfs_smr);
764
765 /*
766 * Preallocate enough nodes to support one-per buf so that
767 * we can not fail an insert. reassignbuf() callers can not
768 * tolerate the insertion failure.
769 */
770 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
771 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
772 UMA_ZONE_NOFREE | UMA_ZONE_SMR);
773 buf_trie_smr = uma_zone_get_smr(buf_trie_zone);
774 uma_prealloc(buf_trie_zone, nbuf);
775
776 vnodes_created = counter_u64_alloc(M_WAITOK);
777 direct_recycles_free_count = counter_u64_alloc(M_WAITOK);
778 vnode_skipped_requeues = counter_u64_alloc(M_WAITOK);
779
780 /*
781 * Initialize the filesystem syncer.
782 */
783 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
784 &syncer_mask);
785 syncer_maxdelay = syncer_mask + 1;
786 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
787 cv_init(&sync_wakeup, "syncer");
788
789 CPU_FOREACH(cpu) {
790 vd = DPCPU_ID_PTR((cpu), vd);
791 bzero(vd, sizeof(*vd));
792 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF);
793 }
794 }
795 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
796
797 /*
798 * Mark a mount point as busy. Used to synchronize access and to delay
799 * unmounting. Eventually, mountlist_mtx is not released on failure.
800 *
801 * vfs_busy() is a custom lock, it can block the caller.
802 * vfs_busy() only sleeps if the unmount is active on the mount point.
803 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
804 * vnode belonging to mp.
805 *
806 * Lookup uses vfs_busy() to traverse mount points.
807 * root fs var fs
808 * / vnode lock A / vnode lock (/var) D
809 * /var vnode lock B /log vnode lock(/var/log) E
810 * vfs_busy lock C vfs_busy lock F
811 *
812 * Within each file system, the lock order is C->A->B and F->D->E.
813 *
814 * When traversing across mounts, the system follows that lock order:
815 *
816 * C->A->B
817 * |
818 * +->F->D->E
819 *
820 * The lookup() process for namei("/var") illustrates the process:
821 * 1. VOP_LOOKUP() obtains B while A is held
822 * 2. vfs_busy() obtains a shared lock on F while A and B are held
823 * 3. vput() releases lock on B
824 * 4. vput() releases lock on A
825 * 5. VFS_ROOT() obtains lock on D while shared lock on F is held
826 * 6. vfs_unbusy() releases shared lock on F
827 * 7. vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
828 * Attempt to lock A (instead of vp_crossmp) while D is held would
829 * violate the global order, causing deadlocks.
830 *
831 * dounmount() locks B while F is drained. Note that for stacked
832 * filesystems, D and B in the example above may be the same lock,
833 * which introdues potential lock order reversal deadlock between
834 * dounmount() and step 5 above. These filesystems may avoid the LOR
835 * by setting VV_CROSSLOCK on the covered vnode so that lock B will
836 * remain held until after step 5.
837 */
838 int
vfs_busy(struct mount * mp,int flags)839 vfs_busy(struct mount *mp, int flags)
840 {
841 struct mount_pcpu *mpcpu;
842
843 MPASS((flags & ~MBF_MASK) == 0);
844 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
845
846 if (vfs_op_thread_enter(mp, mpcpu)) {
847 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
848 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0);
849 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0);
850 vfs_mp_count_add_pcpu(mpcpu, ref, 1);
851 vfs_mp_count_add_pcpu(mpcpu, lockref, 1);
852 vfs_op_thread_exit(mp, mpcpu);
853 if (flags & MBF_MNTLSTLOCK)
854 mtx_unlock(&mountlist_mtx);
855 return (0);
856 }
857
858 MNT_ILOCK(mp);
859 vfs_assert_mount_counters(mp);
860 MNT_REF(mp);
861 /*
862 * If mount point is currently being unmounted, sleep until the
863 * mount point fate is decided. If thread doing the unmounting fails,
864 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
865 * that this mount point has survived the unmount attempt and vfs_busy
866 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
867 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
868 * about to be really destroyed. vfs_busy needs to release its
869 * reference on the mount point in this case and return with ENOENT,
870 * telling the caller the mount it tried to busy is no longer valid.
871 */
872 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
873 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers),
874 ("%s: non-empty upper mount list with pending unmount",
875 __func__));
876 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
877 MNT_REL(mp);
878 MNT_IUNLOCK(mp);
879 CTR1(KTR_VFS, "%s: failed busying before sleeping",
880 __func__);
881 return (ENOENT);
882 }
883 if (flags & MBF_MNTLSTLOCK)
884 mtx_unlock(&mountlist_mtx);
885 mp->mnt_kern_flag |= MNTK_MWAIT;
886 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
887 if (flags & MBF_MNTLSTLOCK)
888 mtx_lock(&mountlist_mtx);
889 MNT_ILOCK(mp);
890 }
891 if (flags & MBF_MNTLSTLOCK)
892 mtx_unlock(&mountlist_mtx);
893 mp->mnt_lockref++;
894 MNT_IUNLOCK(mp);
895 return (0);
896 }
897
898 /*
899 * Free a busy filesystem.
900 */
901 void
vfs_unbusy(struct mount * mp)902 vfs_unbusy(struct mount *mp)
903 {
904 struct mount_pcpu *mpcpu;
905 int c;
906
907 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
908
909 if (vfs_op_thread_enter(mp, mpcpu)) {
910 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
911 vfs_mp_count_sub_pcpu(mpcpu, lockref, 1);
912 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
913 vfs_op_thread_exit(mp, mpcpu);
914 return;
915 }
916
917 MNT_ILOCK(mp);
918 vfs_assert_mount_counters(mp);
919 MNT_REL(mp);
920 c = --mp->mnt_lockref;
921 if (mp->mnt_vfs_ops == 0) {
922 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
923 MNT_IUNLOCK(mp);
924 return;
925 }
926 if (c < 0)
927 vfs_dump_mount_counters(mp);
928 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
929 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
930 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
931 mp->mnt_kern_flag &= ~MNTK_DRAINING;
932 wakeup(&mp->mnt_lockref);
933 }
934 MNT_IUNLOCK(mp);
935 }
936
937 /*
938 * Lookup a mount point by filesystem identifier.
939 */
940 struct mount *
vfs_getvfs(fsid_t * fsid)941 vfs_getvfs(fsid_t *fsid)
942 {
943 struct mount *mp;
944
945 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
946 mtx_lock(&mountlist_mtx);
947 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
948 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
949 vfs_ref(mp);
950 mtx_unlock(&mountlist_mtx);
951 return (mp);
952 }
953 }
954 mtx_unlock(&mountlist_mtx);
955 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
956 return ((struct mount *) 0);
957 }
958
959 /*
960 * Lookup a mount point by filesystem identifier, busying it before
961 * returning.
962 *
963 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
964 * cache for popular filesystem identifiers. The cache is lockess, using
965 * the fact that struct mount's are never freed. In worst case we may
966 * get pointer to unmounted or even different filesystem, so we have to
967 * check what we got, and go slow way if so.
968 */
969 struct mount *
vfs_busyfs(fsid_t * fsid)970 vfs_busyfs(fsid_t *fsid)
971 {
972 #define FSID_CACHE_SIZE 256
973 typedef struct mount * volatile vmp_t;
974 static vmp_t cache[FSID_CACHE_SIZE];
975 struct mount *mp;
976 int error;
977 uint32_t hash;
978
979 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
980 hash = fsid->val[0] ^ fsid->val[1];
981 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
982 mp = cache[hash];
983 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0)
984 goto slow;
985 if (vfs_busy(mp, 0) != 0) {
986 cache[hash] = NULL;
987 goto slow;
988 }
989 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0)
990 return (mp);
991 else
992 vfs_unbusy(mp);
993
994 slow:
995 mtx_lock(&mountlist_mtx);
996 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
997 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
998 error = vfs_busy(mp, MBF_MNTLSTLOCK);
999 if (error) {
1000 cache[hash] = NULL;
1001 mtx_unlock(&mountlist_mtx);
1002 return (NULL);
1003 }
1004 cache[hash] = mp;
1005 return (mp);
1006 }
1007 }
1008 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
1009 mtx_unlock(&mountlist_mtx);
1010 return ((struct mount *) 0);
1011 }
1012
1013 /*
1014 * Check if a user can access privileged mount options.
1015 */
1016 int
vfs_suser(struct mount * mp,struct thread * td)1017 vfs_suser(struct mount *mp, struct thread *td)
1018 {
1019 int error;
1020
1021 if (jailed(td->td_ucred)) {
1022 /*
1023 * If the jail of the calling thread lacks permission for
1024 * this type of file system, deny immediately.
1025 */
1026 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag))
1027 return (EPERM);
1028
1029 /*
1030 * If the file system was mounted outside the jail of the
1031 * calling thread, deny immediately.
1032 */
1033 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
1034 return (EPERM);
1035 }
1036
1037 /*
1038 * If file system supports delegated administration, we don't check
1039 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
1040 * by the file system itself.
1041 * If this is not the user that did original mount, we check for
1042 * the PRIV_VFS_MOUNT_OWNER privilege.
1043 */
1044 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
1045 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
1046 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
1047 return (error);
1048 }
1049 return (0);
1050 }
1051
1052 /*
1053 * Get a new unique fsid. Try to make its val[0] unique, since this value
1054 * will be used to create fake device numbers for stat(). Also try (but
1055 * not so hard) make its val[0] unique mod 2^16, since some emulators only
1056 * support 16-bit device numbers. We end up with unique val[0]'s for the
1057 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
1058 *
1059 * Keep in mind that several mounts may be running in parallel. Starting
1060 * the search one past where the previous search terminated is both a
1061 * micro-optimization and a defense against returning the same fsid to
1062 * different mounts.
1063 */
1064 void
vfs_getnewfsid(struct mount * mp)1065 vfs_getnewfsid(struct mount *mp)
1066 {
1067 static uint16_t mntid_base;
1068 struct mount *nmp;
1069 fsid_t tfsid;
1070 int mtype;
1071
1072 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
1073 mtx_lock(&mntid_mtx);
1074 mtype = mp->mnt_vfc->vfc_typenum;
1075 tfsid.val[1] = mtype;
1076 mtype = (mtype & 0xFF) << 24;
1077 for (;;) {
1078 tfsid.val[0] = makedev(255,
1079 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
1080 mntid_base++;
1081 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
1082 break;
1083 vfs_rel(nmp);
1084 }
1085 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
1086 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
1087 mtx_unlock(&mntid_mtx);
1088 }
1089
1090 /*
1091 * Knob to control the precision of file timestamps:
1092 *
1093 * 0 = seconds only; nanoseconds zeroed.
1094 * 1 = seconds and nanoseconds, accurate within 1/HZ.
1095 * 2 = seconds and nanoseconds, truncated to microseconds.
1096 * >=3 = seconds and nanoseconds, maximum precision.
1097 */
1098 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
1099
1100 static int timestamp_precision = TSP_USEC;
1101 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
1102 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
1103 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, "
1104 "3+: sec + ns (max. precision))");
1105
1106 /*
1107 * Get a current timestamp.
1108 */
1109 void
vfs_timestamp(struct timespec * tsp)1110 vfs_timestamp(struct timespec *tsp)
1111 {
1112 struct timeval tv;
1113
1114 switch (timestamp_precision) {
1115 case TSP_SEC:
1116 tsp->tv_sec = time_second;
1117 tsp->tv_nsec = 0;
1118 break;
1119 case TSP_HZ:
1120 getnanotime(tsp);
1121 break;
1122 case TSP_USEC:
1123 microtime(&tv);
1124 TIMEVAL_TO_TIMESPEC(&tv, tsp);
1125 break;
1126 case TSP_NSEC:
1127 default:
1128 nanotime(tsp);
1129 break;
1130 }
1131 }
1132
1133 /*
1134 * Set vnode attributes to VNOVAL
1135 */
1136 void
vattr_null(struct vattr * vap)1137 vattr_null(struct vattr *vap)
1138 {
1139
1140 vap->va_type = VNON;
1141 vap->va_size = VNOVAL;
1142 vap->va_bytes = VNOVAL;
1143 vap->va_mode = VNOVAL;
1144 vap->va_nlink = VNOVAL;
1145 vap->va_uid = VNOVAL;
1146 vap->va_gid = VNOVAL;
1147 vap->va_fsid = VNOVAL;
1148 vap->va_fileid = VNOVAL;
1149 vap->va_blocksize = VNOVAL;
1150 vap->va_rdev = VNOVAL;
1151 vap->va_atime.tv_sec = VNOVAL;
1152 vap->va_atime.tv_nsec = VNOVAL;
1153 vap->va_mtime.tv_sec = VNOVAL;
1154 vap->va_mtime.tv_nsec = VNOVAL;
1155 vap->va_ctime.tv_sec = VNOVAL;
1156 vap->va_ctime.tv_nsec = VNOVAL;
1157 vap->va_birthtime.tv_sec = VNOVAL;
1158 vap->va_birthtime.tv_nsec = VNOVAL;
1159 vap->va_flags = VNOVAL;
1160 vap->va_gen = VNOVAL;
1161 vap->va_vaflags = 0;
1162 }
1163
1164 /*
1165 * Try to reduce the total number of vnodes.
1166 *
1167 * This routine (and its user) are buggy in at least the following ways:
1168 * - all parameters were picked years ago when RAM sizes were significantly
1169 * smaller
1170 * - it can pick vnodes based on pages used by the vm object, but filesystems
1171 * like ZFS don't use it making the pick broken
1172 * - since ZFS has its own aging policy it gets partially combated by this one
1173 * - a dedicated method should be provided for filesystems to let them decide
1174 * whether the vnode should be recycled
1175 *
1176 * This routine is called when we have too many vnodes. It attempts
1177 * to free <count> vnodes and will potentially free vnodes that still
1178 * have VM backing store (VM backing store is typically the cause
1179 * of a vnode blowout so we want to do this). Therefore, this operation
1180 * is not considered cheap.
1181 *
1182 * A number of conditions may prevent a vnode from being reclaimed.
1183 * the buffer cache may have references on the vnode, a directory
1184 * vnode may still have references due to the namei cache representing
1185 * underlying files, or the vnode may be in active use. It is not
1186 * desirable to reuse such vnodes. These conditions may cause the
1187 * number of vnodes to reach some minimum value regardless of what
1188 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
1189 *
1190 * @param reclaim_nc_src Only reclaim directories with outgoing namecache
1191 * entries if this argument is strue
1192 * @param trigger Only reclaim vnodes with fewer than this many resident
1193 * pages.
1194 * @param target How many vnodes to reclaim.
1195 * @return The number of vnodes that were reclaimed.
1196 */
1197 static int
vlrureclaim(bool reclaim_nc_src,int trigger,u_long target)1198 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target)
1199 {
1200 struct vnode *vp, *mvp;
1201 struct mount *mp;
1202 struct vm_object *object;
1203 u_long done;
1204 bool retried;
1205
1206 mtx_assert(&vnode_list_mtx, MA_OWNED);
1207
1208 retried = false;
1209 done = 0;
1210
1211 mvp = vnode_list_reclaim_marker;
1212 restart:
1213 vp = mvp;
1214 while (done < target) {
1215 vp = TAILQ_NEXT(vp, v_vnodelist);
1216 if (__predict_false(vp == NULL))
1217 break;
1218
1219 if (__predict_false(vp->v_type == VMARKER))
1220 continue;
1221
1222 /*
1223 * If it's been deconstructed already, it's still
1224 * referenced, or it exceeds the trigger, skip it.
1225 * Also skip free vnodes. We are trying to make space
1226 * for more free vnodes, not reduce their count.
1227 */
1228 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 ||
1229 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)))
1230 goto next_iter;
1231
1232 if (vp->v_type == VBAD || vp->v_type == VNON)
1233 goto next_iter;
1234
1235 object = atomic_load_ptr(&vp->v_object);
1236 if (object == NULL || object->resident_page_count > trigger) {
1237 goto next_iter;
1238 }
1239
1240 /*
1241 * Handle races against vnode allocation. Filesystems lock the
1242 * vnode some time after it gets returned from getnewvnode,
1243 * despite type and hold count being manipulated earlier.
1244 * Resorting to checking v_mount restores guarantees present
1245 * before the global list was reworked to contain all vnodes.
1246 */
1247 if (!VI_TRYLOCK(vp))
1248 goto next_iter;
1249 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1250 VI_UNLOCK(vp);
1251 goto next_iter;
1252 }
1253 if (vp->v_mount == NULL) {
1254 VI_UNLOCK(vp);
1255 goto next_iter;
1256 }
1257 vholdl(vp);
1258 VI_UNLOCK(vp);
1259 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1260 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1261 mtx_unlock(&vnode_list_mtx);
1262
1263 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1264 vdrop_recycle(vp);
1265 goto next_iter_unlocked;
1266 }
1267 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) {
1268 vdrop_recycle(vp);
1269 vn_finished_write(mp);
1270 goto next_iter_unlocked;
1271 }
1272
1273 VI_LOCK(vp);
1274 if (vp->v_usecount > 0 ||
1275 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1276 (vp->v_object != NULL && vp->v_object->handle == vp &&
1277 vp->v_object->resident_page_count > trigger)) {
1278 VOP_UNLOCK(vp);
1279 vdropl_recycle(vp);
1280 vn_finished_write(mp);
1281 goto next_iter_unlocked;
1282 }
1283 recycles_count++;
1284 vgonel(vp);
1285 VOP_UNLOCK(vp);
1286 vdropl_recycle(vp);
1287 vn_finished_write(mp);
1288 done++;
1289 next_iter_unlocked:
1290 maybe_yield();
1291 mtx_lock(&vnode_list_mtx);
1292 goto restart;
1293 next_iter:
1294 MPASS(vp->v_type != VMARKER);
1295 if (!should_yield())
1296 continue;
1297 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1298 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1299 mtx_unlock(&vnode_list_mtx);
1300 kern_yield(PRI_USER);
1301 mtx_lock(&vnode_list_mtx);
1302 goto restart;
1303 }
1304 if (done == 0 && !retried) {
1305 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1306 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1307 retried = true;
1308 goto restart;
1309 }
1310 return (done);
1311 }
1312
1313 static int max_free_per_call = 10000;
1314 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_free_per_call, 0,
1315 "limit on vnode free requests per call to the vnlru_free routine (legacy)");
1316 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, max_free_per_call, CTLFLAG_RW,
1317 &max_free_per_call, 0,
1318 "limit on vnode free requests per call to the vnlru_free routine");
1319
1320 /*
1321 * Attempt to recycle requested amount of free vnodes.
1322 */
1323 static int
vnlru_free_impl(int count,struct vfsops * mnt_op,struct vnode * mvp,bool isvnlru)1324 vnlru_free_impl(int count, struct vfsops *mnt_op, struct vnode *mvp, bool isvnlru)
1325 {
1326 struct vnode *vp;
1327 struct mount *mp;
1328 int ocount;
1329 bool retried;
1330
1331 mtx_assert(&vnode_list_mtx, MA_OWNED);
1332 if (count > max_free_per_call)
1333 count = max_free_per_call;
1334 if (count == 0) {
1335 mtx_unlock(&vnode_list_mtx);
1336 return (0);
1337 }
1338 ocount = count;
1339 retried = false;
1340 vp = mvp;
1341 for (;;) {
1342 vp = TAILQ_NEXT(vp, v_vnodelist);
1343 if (__predict_false(vp == NULL)) {
1344 /*
1345 * The free vnode marker can be past eligible vnodes:
1346 * 1. if vdbatch_process trylock failed
1347 * 2. if vtryrecycle failed
1348 *
1349 * If so, start the scan from scratch.
1350 */
1351 if (!retried && vnlru_read_freevnodes() > 0) {
1352 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1353 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1354 vp = mvp;
1355 retried = true;
1356 continue;
1357 }
1358
1359 /*
1360 * Give up
1361 */
1362 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1363 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist);
1364 mtx_unlock(&vnode_list_mtx);
1365 break;
1366 }
1367 if (__predict_false(vp->v_type == VMARKER))
1368 continue;
1369 if (vp->v_holdcnt > 0)
1370 continue;
1371 /*
1372 * Don't recycle if our vnode is from different type
1373 * of mount point. Note that mp is type-safe, the
1374 * check does not reach unmapped address even if
1375 * vnode is reclaimed.
1376 */
1377 if (mnt_op != NULL && (mp = vp->v_mount) != NULL &&
1378 mp->mnt_op != mnt_op) {
1379 continue;
1380 }
1381 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1382 continue;
1383 }
1384 if (!vhold_recycle_free(vp))
1385 continue;
1386 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1387 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1388 mtx_unlock(&vnode_list_mtx);
1389 /*
1390 * FIXME: ignores the return value, meaning it may be nothing
1391 * got recycled but it claims otherwise to the caller.
1392 *
1393 * Originally the value started being ignored in 2005 with
1394 * 114a1006a8204aa156e1f9ad6476cdff89cada7f .
1395 *
1396 * Respecting the value can run into significant stalls if most
1397 * vnodes belong to one file system and it has writes
1398 * suspended. In presence of many threads and millions of
1399 * vnodes they keep contending on the vnode_list_mtx lock only
1400 * to find vnodes they can't recycle.
1401 *
1402 * The solution would be to pre-check if the vnode is likely to
1403 * be recycle-able, but it needs to happen with the
1404 * vnode_list_mtx lock held. This runs into a problem where
1405 * VOP_GETWRITEMOUNT (currently needed to find out about if
1406 * writes are frozen) can take locks which LOR against it.
1407 *
1408 * Check nullfs for one example (null_getwritemount).
1409 */
1410 vtryrecycle(vp, isvnlru);
1411 count--;
1412 if (count == 0) {
1413 break;
1414 }
1415 mtx_lock(&vnode_list_mtx);
1416 vp = mvp;
1417 }
1418 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1419 return (ocount - count);
1420 }
1421
1422 /*
1423 * XXX: returns without vnode_list_mtx locked!
1424 */
1425 static int
vnlru_free_locked_direct(int count)1426 vnlru_free_locked_direct(int count)
1427 {
1428 int ret;
1429
1430 mtx_assert(&vnode_list_mtx, MA_OWNED);
1431 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, false);
1432 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1433 return (ret);
1434 }
1435
1436 static int
vnlru_free_locked_vnlru(int count)1437 vnlru_free_locked_vnlru(int count)
1438 {
1439 int ret;
1440
1441 mtx_assert(&vnode_list_mtx, MA_OWNED);
1442 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, true);
1443 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1444 return (ret);
1445 }
1446
1447 static int
vnlru_free_vnlru(int count)1448 vnlru_free_vnlru(int count)
1449 {
1450
1451 mtx_lock(&vnode_list_mtx);
1452 return (vnlru_free_locked_vnlru(count));
1453 }
1454
1455 void
vnlru_free_vfsops(int count,struct vfsops * mnt_op,struct vnode * mvp)1456 vnlru_free_vfsops(int count, struct vfsops *mnt_op, struct vnode *mvp)
1457 {
1458
1459 MPASS(mnt_op != NULL);
1460 MPASS(mvp != NULL);
1461 VNPASS(mvp->v_type == VMARKER, mvp);
1462 mtx_lock(&vnode_list_mtx);
1463 vnlru_free_impl(count, mnt_op, mvp, true);
1464 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1465 }
1466
1467 struct vnode *
vnlru_alloc_marker(void)1468 vnlru_alloc_marker(void)
1469 {
1470 struct vnode *mvp;
1471
1472 mvp = vn_alloc_marker(NULL);
1473 mtx_lock(&vnode_list_mtx);
1474 TAILQ_INSERT_BEFORE(vnode_list_free_marker, mvp, v_vnodelist);
1475 mtx_unlock(&vnode_list_mtx);
1476 return (mvp);
1477 }
1478
1479 void
vnlru_free_marker(struct vnode * mvp)1480 vnlru_free_marker(struct vnode *mvp)
1481 {
1482 mtx_lock(&vnode_list_mtx);
1483 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1484 mtx_unlock(&vnode_list_mtx);
1485 vn_free_marker(mvp);
1486 }
1487
1488 static void
vnlru_recalc(void)1489 vnlru_recalc(void)
1490 {
1491
1492 mtx_assert(&vnode_list_mtx, MA_OWNED);
1493 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1494 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1495 vlowat = vhiwat / 2;
1496 }
1497
1498 /*
1499 * Attempt to recycle vnodes in a context that is always safe to block.
1500 * Calling vlrurecycle() from the bowels of filesystem code has some
1501 * interesting deadlock problems.
1502 */
1503 static struct proc *vnlruproc;
1504 static int vnlruproc_sig;
1505 static u_long vnlruproc_kicks;
1506
1507 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, kicks, CTLFLAG_RD, &vnlruproc_kicks, 0,
1508 "Number of times vnlru awakened due to vnode shortage");
1509
1510 #define VNLRU_COUNT_SLOP 100
1511
1512 /*
1513 * The main freevnodes counter is only updated when a counter local to CPU
1514 * diverges from 0 by more than VNLRU_FREEVNODES_SLOP. CPUs are conditionally
1515 * walked to compute a more accurate total.
1516 *
1517 * Note: the actual value at any given moment can still exceed slop, but it
1518 * should not be by significant margin in practice.
1519 */
1520 #define VNLRU_FREEVNODES_SLOP 126
1521
1522 static void __noinline
vfs_freevnodes_rollup(int8_t * lfreevnodes)1523 vfs_freevnodes_rollup(int8_t *lfreevnodes)
1524 {
1525
1526 atomic_add_long(&freevnodes, *lfreevnodes);
1527 *lfreevnodes = 0;
1528 critical_exit();
1529 }
1530
1531 static __inline void
vfs_freevnodes_inc(void)1532 vfs_freevnodes_inc(void)
1533 {
1534 int8_t *lfreevnodes;
1535
1536 critical_enter();
1537 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1538 (*lfreevnodes)++;
1539 if (__predict_false(*lfreevnodes == VNLRU_FREEVNODES_SLOP))
1540 vfs_freevnodes_rollup(lfreevnodes);
1541 else
1542 critical_exit();
1543 }
1544
1545 static __inline void
vfs_freevnodes_dec(void)1546 vfs_freevnodes_dec(void)
1547 {
1548 int8_t *lfreevnodes;
1549
1550 critical_enter();
1551 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1552 (*lfreevnodes)--;
1553 if (__predict_false(*lfreevnodes == -VNLRU_FREEVNODES_SLOP))
1554 vfs_freevnodes_rollup(lfreevnodes);
1555 else
1556 critical_exit();
1557 }
1558
1559 static u_long
vnlru_read_freevnodes(void)1560 vnlru_read_freevnodes(void)
1561 {
1562 long slop, rfreevnodes, rfreevnodes_old;
1563 int cpu;
1564
1565 rfreevnodes = atomic_load_long(&freevnodes);
1566 rfreevnodes_old = atomic_load_long(&freevnodes_old);
1567
1568 if (rfreevnodes > rfreevnodes_old)
1569 slop = rfreevnodes - rfreevnodes_old;
1570 else
1571 slop = rfreevnodes_old - rfreevnodes;
1572 if (slop < VNLRU_FREEVNODES_SLOP)
1573 return (rfreevnodes >= 0 ? rfreevnodes : 0);
1574 CPU_FOREACH(cpu) {
1575 rfreevnodes += cpuid_to_pcpu[cpu]->pc_vfs_freevnodes;
1576 }
1577 atomic_store_long(&freevnodes_old, rfreevnodes);
1578 return (freevnodes_old >= 0 ? freevnodes_old : 0);
1579 }
1580
1581 static bool
vnlru_under(u_long rnumvnodes,u_long limit)1582 vnlru_under(u_long rnumvnodes, u_long limit)
1583 {
1584 u_long rfreevnodes, space;
1585
1586 if (__predict_false(rnumvnodes > desiredvnodes))
1587 return (true);
1588
1589 space = desiredvnodes - rnumvnodes;
1590 if (space < limit) {
1591 rfreevnodes = vnlru_read_freevnodes();
1592 if (rfreevnodes > wantfreevnodes)
1593 space += rfreevnodes - wantfreevnodes;
1594 }
1595 return (space < limit);
1596 }
1597
1598 static void
vnlru_kick_locked(void)1599 vnlru_kick_locked(void)
1600 {
1601
1602 mtx_assert(&vnode_list_mtx, MA_OWNED);
1603 if (vnlruproc_sig == 0) {
1604 vnlruproc_sig = 1;
1605 vnlruproc_kicks++;
1606 wakeup(vnlruproc);
1607 }
1608 }
1609
1610 static void
vnlru_kick_cond(void)1611 vnlru_kick_cond(void)
1612 {
1613
1614 if (vnlru_read_freevnodes() > wantfreevnodes)
1615 return;
1616
1617 if (vnlruproc_sig)
1618 return;
1619 mtx_lock(&vnode_list_mtx);
1620 vnlru_kick_locked();
1621 mtx_unlock(&vnode_list_mtx);
1622 }
1623
1624 static void
vnlru_proc_sleep(void)1625 vnlru_proc_sleep(void)
1626 {
1627
1628 if (vnlruproc_sig) {
1629 vnlruproc_sig = 0;
1630 wakeup(&vnlruproc_sig);
1631 }
1632 msleep(vnlruproc, &vnode_list_mtx, PVFS|PDROP, "vlruwt", hz);
1633 }
1634
1635 /*
1636 * A lighter version of the machinery below.
1637 *
1638 * Tries to reach goals only by recycling free vnodes and does not invoke
1639 * uma_reclaim(UMA_RECLAIM_DRAIN).
1640 *
1641 * This works around pathological behavior in vnlru in presence of tons of free
1642 * vnodes, but without having to rewrite the machinery at this time. Said
1643 * behavior boils down to continuously trying to reclaim all kinds of vnodes
1644 * (cycling through all levels of "force") when the count is transiently above
1645 * limit. This happens a lot when all vnodes are used up and vn_alloc
1646 * speculatively increments the counter.
1647 *
1648 * Sample testcase: vnode limit 8388608, 20 separate directory trees each with
1649 * 1 million files in total and 20 find(1) processes stating them in parallel
1650 * (one per each tree).
1651 *
1652 * On a kernel with only stock machinery this needs anywhere between 60 and 120
1653 * seconds to execute (time varies *wildly* between runs). With the workaround
1654 * it consistently stays around 20 seconds [it got further down with later
1655 * changes].
1656 *
1657 * That is to say the entire thing needs a fundamental redesign (most notably
1658 * to accommodate faster recycling), the above only tries to get it ouf the way.
1659 *
1660 * Return values are:
1661 * -1 -- fallback to regular vnlru loop
1662 * 0 -- do nothing, go to sleep
1663 * >0 -- recycle this many vnodes
1664 */
1665 static long
vnlru_proc_light_pick(void)1666 vnlru_proc_light_pick(void)
1667 {
1668 u_long rnumvnodes, rfreevnodes;
1669
1670 if (vstir || vnlruproc_sig == 1)
1671 return (-1);
1672
1673 rnumvnodes = atomic_load_long(&numvnodes);
1674 rfreevnodes = vnlru_read_freevnodes();
1675
1676 /*
1677 * vnode limit might have changed and now we may be at a significant
1678 * excess. Bail if we can't sort it out with free vnodes.
1679 *
1680 * Due to atomic updates the count can legitimately go above
1681 * the limit for a short period, don't bother doing anything in
1682 * that case.
1683 */
1684 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP + 10) {
1685 if (rnumvnodes - rfreevnodes >= desiredvnodes ||
1686 rfreevnodes <= wantfreevnodes) {
1687 return (-1);
1688 }
1689
1690 return (rnumvnodes - desiredvnodes);
1691 }
1692
1693 /*
1694 * Don't try to reach wantfreevnodes target if there are too few vnodes
1695 * to begin with.
1696 */
1697 if (rnumvnodes < wantfreevnodes) {
1698 return (0);
1699 }
1700
1701 if (rfreevnodes < wantfreevnodes) {
1702 return (-1);
1703 }
1704
1705 return (0);
1706 }
1707
1708 static bool
vnlru_proc_light(void)1709 vnlru_proc_light(void)
1710 {
1711 long freecount;
1712
1713 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1714
1715 freecount = vnlru_proc_light_pick();
1716 if (freecount == -1)
1717 return (false);
1718
1719 if (freecount != 0) {
1720 vnlru_free_vnlru(freecount);
1721 }
1722
1723 mtx_lock(&vnode_list_mtx);
1724 vnlru_proc_sleep();
1725 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1726 return (true);
1727 }
1728
1729 static u_long uma_reclaim_calls;
1730 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, uma_reclaim_calls, CTLFLAG_RD | CTLFLAG_STATS,
1731 &uma_reclaim_calls, 0, "Number of calls to uma_reclaim");
1732
1733 static void
vnlru_proc(void)1734 vnlru_proc(void)
1735 {
1736 u_long rnumvnodes, rfreevnodes, target;
1737 unsigned long onumvnodes;
1738 int done, force, trigger, usevnodes;
1739 bool reclaim_nc_src, want_reread;
1740
1741 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1742 SHUTDOWN_PRI_FIRST);
1743
1744 force = 0;
1745 want_reread = false;
1746 for (;;) {
1747 kproc_suspend_check(vnlruproc);
1748
1749 if (force == 0 && vnlru_proc_light())
1750 continue;
1751
1752 mtx_lock(&vnode_list_mtx);
1753 rnumvnodes = atomic_load_long(&numvnodes);
1754
1755 if (want_reread) {
1756 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0;
1757 want_reread = false;
1758 }
1759
1760 /*
1761 * If numvnodes is too large (due to desiredvnodes being
1762 * adjusted using its sysctl, or emergency growth), first
1763 * try to reduce it by discarding free vnodes.
1764 */
1765 if (rnumvnodes > desiredvnodes + 10) {
1766 vnlru_free_locked_vnlru(rnumvnodes - desiredvnodes);
1767 mtx_lock(&vnode_list_mtx);
1768 rnumvnodes = atomic_load_long(&numvnodes);
1769 }
1770 /*
1771 * Sleep if the vnode cache is in a good state. This is
1772 * when it is not over-full and has space for about a 4%
1773 * or 9% expansion (by growing its size or inexcessively
1774 * reducing free vnode count). Otherwise, try to reclaim
1775 * space for a 10% expansion.
1776 */
1777 if (vstir && force == 0) {
1778 force = 1;
1779 vstir = false;
1780 }
1781 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) {
1782 vnlru_proc_sleep();
1783 continue;
1784 }
1785 rfreevnodes = vnlru_read_freevnodes();
1786
1787 onumvnodes = rnumvnodes;
1788 /*
1789 * Calculate parameters for recycling. These are the same
1790 * throughout the loop to give some semblance of fairness.
1791 * The trigger point is to avoid recycling vnodes with lots
1792 * of resident pages. We aren't trying to free memory; we
1793 * are trying to recycle or at least free vnodes.
1794 */
1795 if (rnumvnodes <= desiredvnodes)
1796 usevnodes = rnumvnodes - rfreevnodes;
1797 else
1798 usevnodes = rnumvnodes;
1799 if (usevnodes <= 0)
1800 usevnodes = 1;
1801 /*
1802 * The trigger value is chosen to give a conservatively
1803 * large value to ensure that it alone doesn't prevent
1804 * making progress. The value can easily be so large that
1805 * it is effectively infinite in some congested and
1806 * misconfigured cases, and this is necessary. Normally
1807 * it is about 8 to 100 (pages), which is quite large.
1808 */
1809 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1810 if (force < 2)
1811 trigger = vsmalltrigger;
1812 reclaim_nc_src = force >= 3;
1813 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1);
1814 target = target / 10 + 1;
1815 done = vlrureclaim(reclaim_nc_src, trigger, target);
1816 mtx_unlock(&vnode_list_mtx);
1817 /*
1818 * Total number of vnodes can transiently go slightly above the
1819 * limit (see vn_alloc_hard), no need to call uma_reclaim if
1820 * this happens.
1821 */
1822 if (onumvnodes + VNLRU_COUNT_SLOP + 1000 > desiredvnodes &&
1823 numvnodes <= desiredvnodes) {
1824 uma_reclaim_calls++;
1825 uma_reclaim(UMA_RECLAIM_DRAIN);
1826 }
1827 if (done == 0) {
1828 if (force == 0 || force == 1) {
1829 force = 2;
1830 continue;
1831 }
1832 if (force == 2) {
1833 force = 3;
1834 continue;
1835 }
1836 want_reread = true;
1837 force = 0;
1838 vnlru_nowhere++;
1839 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1840 } else {
1841 want_reread = true;
1842 kern_yield(PRI_USER);
1843 }
1844 }
1845 }
1846
1847 static struct kproc_desc vnlru_kp = {
1848 "vnlru",
1849 vnlru_proc,
1850 &vnlruproc
1851 };
1852 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1853 &vnlru_kp);
1854
1855 /*
1856 * Routines having to do with the management of the vnode table.
1857 */
1858
1859 /*
1860 * Try to recycle a freed vnode.
1861 */
1862 static int
vtryrecycle(struct vnode * vp,bool isvnlru)1863 vtryrecycle(struct vnode *vp, bool isvnlru)
1864 {
1865 struct mount *vnmp;
1866
1867 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1868 VNPASS(vp->v_holdcnt > 0, vp);
1869 /*
1870 * This vnode may found and locked via some other list, if so we
1871 * can't recycle it yet.
1872 */
1873 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1874 CTR2(KTR_VFS,
1875 "%s: impossible to recycle, vp %p lock is already held",
1876 __func__, vp);
1877 vdrop_recycle(vp);
1878 return (EWOULDBLOCK);
1879 }
1880 /*
1881 * Don't recycle if its filesystem is being suspended.
1882 */
1883 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1884 VOP_UNLOCK(vp);
1885 CTR2(KTR_VFS,
1886 "%s: impossible to recycle, cannot start the write for %p",
1887 __func__, vp);
1888 vdrop_recycle(vp);
1889 return (EBUSY);
1890 }
1891 /*
1892 * If we got this far, we need to acquire the interlock and see if
1893 * anyone picked up this vnode from another list. If not, we will
1894 * mark it with DOOMED via vgonel() so that anyone who does find it
1895 * will skip over it.
1896 */
1897 VI_LOCK(vp);
1898 if (vp->v_usecount) {
1899 VOP_UNLOCK(vp);
1900 vdropl_recycle(vp);
1901 vn_finished_write(vnmp);
1902 CTR2(KTR_VFS,
1903 "%s: impossible to recycle, %p is already referenced",
1904 __func__, vp);
1905 return (EBUSY);
1906 }
1907 if (!VN_IS_DOOMED(vp)) {
1908 if (isvnlru)
1909 recycles_free_count++;
1910 else
1911 counter_u64_add(direct_recycles_free_count, 1);
1912 vgonel(vp);
1913 }
1914 VOP_UNLOCK(vp);
1915 vdropl_recycle(vp);
1916 vn_finished_write(vnmp);
1917 return (0);
1918 }
1919
1920 /*
1921 * Allocate a new vnode.
1922 *
1923 * The operation never returns an error. Returning an error was disabled
1924 * in r145385 (dated 2005) with the following comment:
1925 *
1926 * XXX Not all VFS_VGET/ffs_vget callers check returns.
1927 *
1928 * Given the age of this commit (almost 15 years at the time of writing this
1929 * comment) restoring the ability to fail requires a significant audit of
1930 * all codepaths.
1931 *
1932 * The routine can try to free a vnode or stall for up to 1 second waiting for
1933 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation.
1934 */
1935 static u_long vn_alloc_cyclecount;
1936 static u_long vn_alloc_sleeps;
1937
1938 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, alloc_sleeps, CTLFLAG_RD, &vn_alloc_sleeps, 0,
1939 "Number of times vnode allocation blocked waiting on vnlru");
1940
1941 static struct vnode * __noinline
vn_alloc_hard(struct mount * mp,u_long rnumvnodes,bool bumped)1942 vn_alloc_hard(struct mount *mp, u_long rnumvnodes, bool bumped)
1943 {
1944 u_long rfreevnodes;
1945
1946 if (bumped) {
1947 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP) {
1948 atomic_subtract_long(&numvnodes, 1);
1949 bumped = false;
1950 }
1951 }
1952
1953 mtx_lock(&vnode_list_mtx);
1954
1955 if (vn_alloc_cyclecount != 0) {
1956 rnumvnodes = atomic_load_long(&numvnodes);
1957 if (rnumvnodes + 1 < desiredvnodes) {
1958 vn_alloc_cyclecount = 0;
1959 mtx_unlock(&vnode_list_mtx);
1960 goto alloc;
1961 }
1962
1963 rfreevnodes = vnlru_read_freevnodes();
1964 if (rfreevnodes < wantfreevnodes) {
1965 if (vn_alloc_cyclecount++ >= rfreevnodes) {
1966 vn_alloc_cyclecount = 0;
1967 vstir = true;
1968 }
1969 } else {
1970 vn_alloc_cyclecount = 0;
1971 }
1972 }
1973
1974 /*
1975 * Grow the vnode cache if it will not be above its target max after
1976 * growing. Otherwise, if there is at least one free vnode, try to
1977 * reclaim 1 item from it before growing the cache (possibly above its
1978 * target max if the reclamation failed or is delayed).
1979 */
1980 if (vnlru_free_locked_direct(1) > 0)
1981 goto alloc;
1982 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1983 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) {
1984 /*
1985 * Wait for space for a new vnode.
1986 */
1987 if (bumped) {
1988 atomic_subtract_long(&numvnodes, 1);
1989 bumped = false;
1990 }
1991 mtx_lock(&vnode_list_mtx);
1992 vnlru_kick_locked();
1993 vn_alloc_sleeps++;
1994 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz);
1995 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes &&
1996 vnlru_read_freevnodes() > 1)
1997 vnlru_free_locked_direct(1);
1998 else
1999 mtx_unlock(&vnode_list_mtx);
2000 }
2001 alloc:
2002 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
2003 if (!bumped)
2004 atomic_add_long(&numvnodes, 1);
2005 vnlru_kick_cond();
2006 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2007 }
2008
2009 static struct vnode *
vn_alloc(struct mount * mp)2010 vn_alloc(struct mount *mp)
2011 {
2012 u_long rnumvnodes;
2013
2014 if (__predict_false(vn_alloc_cyclecount != 0))
2015 return (vn_alloc_hard(mp, 0, false));
2016 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1;
2017 if (__predict_false(vnlru_under(rnumvnodes, vlowat))) {
2018 return (vn_alloc_hard(mp, rnumvnodes, true));
2019 }
2020
2021 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2022 }
2023
2024 static void
vn_free(struct vnode * vp)2025 vn_free(struct vnode *vp)
2026 {
2027
2028 atomic_subtract_long(&numvnodes, 1);
2029 uma_zfree_smr(vnode_zone, vp);
2030 }
2031
2032 /*
2033 * Allocate a new vnode.
2034 */
2035 int
getnewvnode(const char * tag,struct mount * mp,struct vop_vector * vops,struct vnode ** vpp)2036 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
2037 struct vnode **vpp)
2038 {
2039 struct vnode *vp;
2040 struct thread *td;
2041 struct lock_object *lo;
2042
2043 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
2044
2045 KASSERT(vops->registered,
2046 ("%s: not registered vector op %p\n", __func__, vops));
2047 cache_validate_vop_vector(mp, vops);
2048
2049 td = curthread;
2050 if (td->td_vp_reserved != NULL) {
2051 vp = td->td_vp_reserved;
2052 td->td_vp_reserved = NULL;
2053 } else {
2054 vp = vn_alloc(mp);
2055 }
2056 counter_u64_add(vnodes_created, 1);
2057
2058 vn_set_state(vp, VSTATE_UNINITIALIZED);
2059
2060 /*
2061 * Locks are given the generic name "vnode" when created.
2062 * Follow the historic practice of using the filesystem
2063 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
2064 *
2065 * Locks live in a witness group keyed on their name. Thus,
2066 * when a lock is renamed, it must also move from the witness
2067 * group of its old name to the witness group of its new name.
2068 *
2069 * The change only needs to be made when the vnode moves
2070 * from one filesystem type to another. We ensure that each
2071 * filesystem use a single static name pointer for its tag so
2072 * that we can compare pointers rather than doing a strcmp().
2073 */
2074 lo = &vp->v_vnlock->lock_object;
2075 #ifdef WITNESS
2076 if (lo->lo_name != tag) {
2077 #endif
2078 lo->lo_name = tag;
2079 #ifdef WITNESS
2080 WITNESS_DESTROY(lo);
2081 WITNESS_INIT(lo, tag);
2082 }
2083 #endif
2084 /*
2085 * By default, don't allow shared locks unless filesystems opt-in.
2086 */
2087 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
2088 /*
2089 * Finalize various vnode identity bits.
2090 */
2091 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
2092 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
2093 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
2094 vp->v_type = VNON;
2095 vp->v_op = vops;
2096 vp->v_irflag = 0;
2097 v_init_counters(vp);
2098 vn_seqc_init(vp);
2099 vp->v_bufobj.bo_ops = &buf_ops_bio;
2100 #ifdef DIAGNOSTIC
2101 if (mp == NULL && vops != &dead_vnodeops)
2102 printf("NULL mp in getnewvnode(9), tag %s\n", tag);
2103 #endif
2104 #ifdef MAC
2105 mac_vnode_init(vp);
2106 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
2107 mac_vnode_associate_singlelabel(mp, vp);
2108 #endif
2109 if (mp != NULL) {
2110 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
2111 }
2112
2113 /*
2114 * For the filesystems which do not use vfs_hash_insert(),
2115 * still initialize v_hash to have vfs_hash_index() useful.
2116 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
2117 * its own hashing.
2118 */
2119 vp->v_hash = (uintptr_t)vp >> vnsz2log;
2120
2121 *vpp = vp;
2122 return (0);
2123 }
2124
2125 void
getnewvnode_reserve(void)2126 getnewvnode_reserve(void)
2127 {
2128 struct thread *td;
2129
2130 td = curthread;
2131 MPASS(td->td_vp_reserved == NULL);
2132 td->td_vp_reserved = vn_alloc(NULL);
2133 }
2134
2135 void
getnewvnode_drop_reserve(void)2136 getnewvnode_drop_reserve(void)
2137 {
2138 struct thread *td;
2139
2140 td = curthread;
2141 if (td->td_vp_reserved != NULL) {
2142 vn_free(td->td_vp_reserved);
2143 td->td_vp_reserved = NULL;
2144 }
2145 }
2146
2147 static void __noinline
freevnode(struct vnode * vp)2148 freevnode(struct vnode *vp)
2149 {
2150 struct bufobj *bo;
2151
2152 /*
2153 * The vnode has been marked for destruction, so free it.
2154 *
2155 * The vnode will be returned to the zone where it will
2156 * normally remain until it is needed for another vnode. We
2157 * need to cleanup (or verify that the cleanup has already
2158 * been done) any residual data left from its current use
2159 * so as not to contaminate the freshly allocated vnode.
2160 */
2161 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2162 /*
2163 * Paired with vgone.
2164 */
2165 vn_seqc_write_end_free(vp);
2166
2167 bo = &vp->v_bufobj;
2168 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2169 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp);
2170 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2171 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2172 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2173 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2174 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2175 ("clean blk trie not empty"));
2176 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2177 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2178 ("dirty blk trie not empty"));
2179 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp,
2180 ("Dangling rangelock waiters"));
2181 VNASSERT((vp->v_iflag & (VI_DOINGINACT | VI_OWEINACT)) == 0, vp,
2182 ("Leaked inactivation"));
2183 VI_UNLOCK(vp);
2184 cache_assert_no_entries(vp);
2185
2186 #ifdef MAC
2187 mac_vnode_destroy(vp);
2188 #endif
2189 if (vp->v_pollinfo != NULL) {
2190 /*
2191 * Use LK_NOWAIT to shut up witness about the lock. We may get
2192 * here while having another vnode locked when trying to
2193 * satisfy a lookup and needing to recycle.
2194 */
2195 VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT);
2196 destroy_vpollinfo(vp->v_pollinfo);
2197 VOP_UNLOCK(vp);
2198 vp->v_pollinfo = NULL;
2199 }
2200 vp->v_mountedhere = NULL;
2201 vp->v_unpcb = NULL;
2202 vp->v_rdev = NULL;
2203 vp->v_fifoinfo = NULL;
2204 vp->v_iflag = 0;
2205 vp->v_vflag = 0;
2206 bo->bo_flag = 0;
2207 vn_free(vp);
2208 }
2209
2210 /*
2211 * Delete from old mount point vnode list, if on one.
2212 */
2213 static void
delmntque(struct vnode * vp)2214 delmntque(struct vnode *vp)
2215 {
2216 struct mount *mp;
2217
2218 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
2219
2220 mp = vp->v_mount;
2221 MNT_ILOCK(mp);
2222 VI_LOCK(vp);
2223 vp->v_mount = NULL;
2224 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
2225 ("bad mount point vnode list size"));
2226 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2227 mp->mnt_nvnodelistsize--;
2228 MNT_REL(mp);
2229 MNT_IUNLOCK(mp);
2230 /*
2231 * The caller expects the interlock to be still held.
2232 */
2233 ASSERT_VI_LOCKED(vp, __func__);
2234 }
2235
2236 static int
insmntque1_int(struct vnode * vp,struct mount * mp,bool dtr)2237 insmntque1_int(struct vnode *vp, struct mount *mp, bool dtr)
2238 {
2239
2240 KASSERT(vp->v_mount == NULL,
2241 ("insmntque: vnode already on per mount vnode list"));
2242 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
2243 if ((mp->mnt_kern_flag & MNTK_UNLOCKED_INSMNTQUE) == 0) {
2244 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
2245 } else {
2246 KASSERT(!dtr,
2247 ("%s: can't have MNTK_UNLOCKED_INSMNTQUE and cleanup",
2248 __func__));
2249 }
2250
2251 /*
2252 * We acquire the vnode interlock early to ensure that the
2253 * vnode cannot be recycled by another process releasing a
2254 * holdcnt on it before we get it on both the vnode list
2255 * and the active vnode list. The mount mutex protects only
2256 * manipulation of the vnode list and the vnode freelist
2257 * mutex protects only manipulation of the active vnode list.
2258 * Hence the need to hold the vnode interlock throughout.
2259 */
2260 MNT_ILOCK(mp);
2261 VI_LOCK(vp);
2262 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
2263 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
2264 mp->mnt_nvnodelistsize == 0)) &&
2265 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
2266 VI_UNLOCK(vp);
2267 MNT_IUNLOCK(mp);
2268 if (dtr) {
2269 vp->v_data = NULL;
2270 vp->v_op = &dead_vnodeops;
2271 vgone(vp);
2272 vput(vp);
2273 }
2274 return (EBUSY);
2275 }
2276 vp->v_mount = mp;
2277 MNT_REF(mp);
2278 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2279 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
2280 ("neg mount point vnode list size"));
2281 mp->mnt_nvnodelistsize++;
2282 VI_UNLOCK(vp);
2283 MNT_IUNLOCK(mp);
2284 return (0);
2285 }
2286
2287 /*
2288 * Insert into list of vnodes for the new mount point, if available.
2289 * insmntque() reclaims the vnode on insertion failure, insmntque1()
2290 * leaves handling of the vnode to the caller.
2291 */
2292 int
insmntque(struct vnode * vp,struct mount * mp)2293 insmntque(struct vnode *vp, struct mount *mp)
2294 {
2295 return (insmntque1_int(vp, mp, true));
2296 }
2297
2298 int
insmntque1(struct vnode * vp,struct mount * mp)2299 insmntque1(struct vnode *vp, struct mount *mp)
2300 {
2301 return (insmntque1_int(vp, mp, false));
2302 }
2303
2304 /*
2305 * Flush out and invalidate all buffers associated with a bufobj
2306 * Called with the underlying object locked.
2307 */
2308 int
bufobj_invalbuf(struct bufobj * bo,int flags,int slpflag,int slptimeo)2309 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
2310 {
2311 int error;
2312
2313 BO_LOCK(bo);
2314 if (flags & V_SAVE) {
2315 error = bufobj_wwait(bo, slpflag, slptimeo);
2316 if (error) {
2317 BO_UNLOCK(bo);
2318 return (error);
2319 }
2320 if (bo->bo_dirty.bv_cnt > 0) {
2321 BO_UNLOCK(bo);
2322 do {
2323 error = BO_SYNC(bo, MNT_WAIT);
2324 } while (error == ERELOOKUP);
2325 if (error != 0)
2326 return (error);
2327 BO_LOCK(bo);
2328 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) {
2329 BO_UNLOCK(bo);
2330 return (EBUSY);
2331 }
2332 }
2333 }
2334 /*
2335 * If you alter this loop please notice that interlock is dropped and
2336 * reacquired in flushbuflist. Special care is needed to ensure that
2337 * no race conditions occur from this.
2338 */
2339 do {
2340 error = flushbuflist(&bo->bo_clean,
2341 flags, bo, slpflag, slptimeo);
2342 if (error == 0 && !(flags & V_CLEANONLY))
2343 error = flushbuflist(&bo->bo_dirty,
2344 flags, bo, slpflag, slptimeo);
2345 if (error != 0 && error != EAGAIN) {
2346 BO_UNLOCK(bo);
2347 return (error);
2348 }
2349 } while (error != 0);
2350
2351 /*
2352 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
2353 * have write I/O in-progress but if there is a VM object then the
2354 * VM object can also have read-I/O in-progress.
2355 */
2356 do {
2357 bufobj_wwait(bo, 0, 0);
2358 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) {
2359 BO_UNLOCK(bo);
2360 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx");
2361 BO_LOCK(bo);
2362 }
2363 } while (bo->bo_numoutput > 0);
2364 BO_UNLOCK(bo);
2365
2366 /*
2367 * Destroy the copy in the VM cache, too.
2368 */
2369 if (bo->bo_object != NULL &&
2370 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
2371 VM_OBJECT_WLOCK(bo->bo_object);
2372 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
2373 OBJPR_CLEANONLY : 0);
2374 VM_OBJECT_WUNLOCK(bo->bo_object);
2375 }
2376
2377 #ifdef INVARIANTS
2378 BO_LOCK(bo);
2379 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO |
2380 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 ||
2381 bo->bo_clean.bv_cnt > 0))
2382 panic("vinvalbuf: flush failed");
2383 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
2384 bo->bo_dirty.bv_cnt > 0)
2385 panic("vinvalbuf: flush dirty failed");
2386 BO_UNLOCK(bo);
2387 #endif
2388 return (0);
2389 }
2390
2391 /*
2392 * Flush out and invalidate all buffers associated with a vnode.
2393 * Called with the underlying object locked.
2394 */
2395 int
vinvalbuf(struct vnode * vp,int flags,int slpflag,int slptimeo)2396 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
2397 {
2398
2399 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2400 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
2401 if (vp->v_object != NULL && vp->v_object->handle != vp)
2402 return (0);
2403 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
2404 }
2405
2406 /*
2407 * Flush out buffers on the specified list.
2408 *
2409 */
2410 static int
flushbuflist(struct bufv * bufv,int flags,struct bufobj * bo,int slpflag,int slptimeo)2411 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
2412 int slptimeo)
2413 {
2414 struct buf *bp, *nbp;
2415 int retval, error;
2416 daddr_t lblkno;
2417 b_xflags_t xflags;
2418
2419 ASSERT_BO_WLOCKED(bo);
2420
2421 retval = 0;
2422 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
2423 /*
2424 * If we are flushing both V_NORMAL and V_ALT buffers then
2425 * do not skip any buffers. If we are flushing only V_NORMAL
2426 * buffers then skip buffers marked as BX_ALTDATA. If we are
2427 * flushing only V_ALT buffers then skip buffers not marked
2428 * as BX_ALTDATA.
2429 */
2430 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) &&
2431 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) ||
2432 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) {
2433 continue;
2434 }
2435 if (nbp != NULL) {
2436 lblkno = nbp->b_lblkno;
2437 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
2438 }
2439 retval = EAGAIN;
2440 error = BUF_TIMELOCK(bp,
2441 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
2442 "flushbuf", slpflag, slptimeo);
2443 if (error) {
2444 BO_LOCK(bo);
2445 return (error != ENOLCK ? error : EAGAIN);
2446 }
2447 KASSERT(bp->b_bufobj == bo,
2448 ("bp %p wrong b_bufobj %p should be %p",
2449 bp, bp->b_bufobj, bo));
2450 /*
2451 * XXX Since there are no node locks for NFS, I
2452 * believe there is a slight chance that a delayed
2453 * write will occur while sleeping just above, so
2454 * check for it.
2455 */
2456 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
2457 (flags & V_SAVE)) {
2458 bremfree(bp);
2459 bp->b_flags |= B_ASYNC;
2460 bwrite(bp);
2461 BO_LOCK(bo);
2462 return (EAGAIN); /* XXX: why not loop ? */
2463 }
2464 bremfree(bp);
2465 bp->b_flags |= (B_INVAL | B_RELBUF);
2466 bp->b_flags &= ~B_ASYNC;
2467 brelse(bp);
2468 BO_LOCK(bo);
2469 if (nbp == NULL)
2470 break;
2471 nbp = gbincore(bo, lblkno);
2472 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2473 != xflags)
2474 break; /* nbp invalid */
2475 }
2476 return (retval);
2477 }
2478
2479 int
bnoreuselist(struct bufv * bufv,struct bufobj * bo,daddr_t startn,daddr_t endn)2480 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
2481 {
2482 struct buf *bp;
2483 int error;
2484 daddr_t lblkno;
2485
2486 ASSERT_BO_LOCKED(bo);
2487
2488 for (lblkno = startn;;) {
2489 again:
2490 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
2491 if (bp == NULL || bp->b_lblkno >= endn ||
2492 bp->b_lblkno < startn)
2493 break;
2494 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
2495 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
2496 if (error != 0) {
2497 BO_RLOCK(bo);
2498 if (error == ENOLCK)
2499 goto again;
2500 return (error);
2501 }
2502 KASSERT(bp->b_bufobj == bo,
2503 ("bp %p wrong b_bufobj %p should be %p",
2504 bp, bp->b_bufobj, bo));
2505 lblkno = bp->b_lblkno + 1;
2506 if ((bp->b_flags & B_MANAGED) == 0)
2507 bremfree(bp);
2508 bp->b_flags |= B_RELBUF;
2509 /*
2510 * In the VMIO case, use the B_NOREUSE flag to hint that the
2511 * pages backing each buffer in the range are unlikely to be
2512 * reused. Dirty buffers will have the hint applied once
2513 * they've been written.
2514 */
2515 if ((bp->b_flags & B_VMIO) != 0)
2516 bp->b_flags |= B_NOREUSE;
2517 brelse(bp);
2518 BO_RLOCK(bo);
2519 }
2520 return (0);
2521 }
2522
2523 /*
2524 * Truncate a file's buffer and pages to a specified length. This
2525 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
2526 * sync activity.
2527 */
2528 int
vtruncbuf(struct vnode * vp,off_t length,int blksize)2529 vtruncbuf(struct vnode *vp, off_t length, int blksize)
2530 {
2531 struct buf *bp, *nbp;
2532 struct bufobj *bo;
2533 daddr_t startlbn;
2534
2535 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__,
2536 vp, blksize, (uintmax_t)length);
2537
2538 /*
2539 * Round up to the *next* lbn.
2540 */
2541 startlbn = howmany(length, blksize);
2542
2543 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
2544
2545 bo = &vp->v_bufobj;
2546 restart_unlocked:
2547 BO_LOCK(bo);
2548
2549 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN)
2550 ;
2551
2552 if (length > 0) {
2553 /*
2554 * Write out vnode metadata, e.g. indirect blocks.
2555 */
2556 restartsync:
2557 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2558 if (bp->b_lblkno >= 0)
2559 continue;
2560 /*
2561 * Since we hold the vnode lock this should only
2562 * fail if we're racing with the buf daemon.
2563 */
2564 if (BUF_LOCK(bp,
2565 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2566 BO_LOCKPTR(bo)) == ENOLCK)
2567 goto restart_unlocked;
2568
2569 VNASSERT((bp->b_flags & B_DELWRI), vp,
2570 ("buf(%p) on dirty queue without DELWRI", bp));
2571
2572 bremfree(bp);
2573 bawrite(bp);
2574 BO_LOCK(bo);
2575 goto restartsync;
2576 }
2577 }
2578
2579 bufobj_wwait(bo, 0, 0);
2580 BO_UNLOCK(bo);
2581 vnode_pager_setsize(vp, length);
2582
2583 return (0);
2584 }
2585
2586 /*
2587 * Invalidate the cached pages of a file's buffer within the range of block
2588 * numbers [startlbn, endlbn).
2589 */
2590 void
v_inval_buf_range(struct vnode * vp,daddr_t startlbn,daddr_t endlbn,int blksize)2591 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn,
2592 int blksize)
2593 {
2594 struct bufobj *bo;
2595 off_t start, end;
2596
2597 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range");
2598
2599 start = blksize * startlbn;
2600 end = blksize * endlbn;
2601
2602 bo = &vp->v_bufobj;
2603 BO_LOCK(bo);
2604 MPASS(blksize == bo->bo_bsize);
2605
2606 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN)
2607 ;
2608
2609 BO_UNLOCK(bo);
2610 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1));
2611 }
2612
2613 static int
v_inval_buf_range_locked(struct vnode * vp,struct bufobj * bo,daddr_t startlbn,daddr_t endlbn)2614 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
2615 daddr_t startlbn, daddr_t endlbn)
2616 {
2617 struct buf *bp, *nbp;
2618 bool anyfreed;
2619
2620 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked");
2621 ASSERT_BO_LOCKED(bo);
2622
2623 do {
2624 anyfreed = false;
2625 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
2626 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
2627 continue;
2628 if (BUF_LOCK(bp,
2629 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2630 BO_LOCKPTR(bo)) == ENOLCK) {
2631 BO_LOCK(bo);
2632 return (EAGAIN);
2633 }
2634
2635 bremfree(bp);
2636 bp->b_flags |= B_INVAL | B_RELBUF;
2637 bp->b_flags &= ~B_ASYNC;
2638 brelse(bp);
2639 anyfreed = true;
2640
2641 BO_LOCK(bo);
2642 if (nbp != NULL &&
2643 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
2644 nbp->b_vp != vp ||
2645 (nbp->b_flags & B_DELWRI) != 0))
2646 return (EAGAIN);
2647 }
2648
2649 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2650 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
2651 continue;
2652 if (BUF_LOCK(bp,
2653 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2654 BO_LOCKPTR(bo)) == ENOLCK) {
2655 BO_LOCK(bo);
2656 return (EAGAIN);
2657 }
2658 bremfree(bp);
2659 bp->b_flags |= B_INVAL | B_RELBUF;
2660 bp->b_flags &= ~B_ASYNC;
2661 brelse(bp);
2662 anyfreed = true;
2663
2664 BO_LOCK(bo);
2665 if (nbp != NULL &&
2666 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
2667 (nbp->b_vp != vp) ||
2668 (nbp->b_flags & B_DELWRI) == 0))
2669 return (EAGAIN);
2670 }
2671 } while (anyfreed);
2672 return (0);
2673 }
2674
2675 static void
buf_vlist_remove(struct buf * bp)2676 buf_vlist_remove(struct buf *bp)
2677 {
2678 struct bufv *bv;
2679 b_xflags_t flags;
2680
2681 flags = bp->b_xflags;
2682
2683 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
2684 ASSERT_BO_WLOCKED(bp->b_bufobj);
2685 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 &&
2686 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN),
2687 ("%s: buffer %p has invalid queue state", __func__, bp));
2688
2689 if ((flags & BX_VNDIRTY) != 0)
2690 bv = &bp->b_bufobj->bo_dirty;
2691 else
2692 bv = &bp->b_bufobj->bo_clean;
2693 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
2694 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
2695 bv->bv_cnt--;
2696 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
2697 }
2698
2699 /*
2700 * Add the buffer to the sorted clean or dirty block list.
2701 *
2702 * NOTE: xflags is passed as a constant, optimizing this inline function!
2703 */
2704 static void
buf_vlist_add(struct buf * bp,struct bufobj * bo,b_xflags_t xflags)2705 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2706 {
2707 struct bufv *bv;
2708 struct buf *n;
2709 int error;
2710
2711 ASSERT_BO_WLOCKED(bo);
2712 KASSERT((bo->bo_flag & BO_NOBUFS) == 0,
2713 ("buf_vlist_add: bo %p does not allow bufs", bo));
2714 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
2715 ("dead bo %p", bo));
2716 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
2717 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
2718 bp->b_xflags |= xflags;
2719 if (xflags & BX_VNDIRTY)
2720 bv = &bo->bo_dirty;
2721 else
2722 bv = &bo->bo_clean;
2723
2724 /*
2725 * Keep the list ordered. Optimize empty list insertion. Assume
2726 * we tend to grow at the tail so lookup_le should usually be cheaper
2727 * than _ge.
2728 */
2729 if (bv->bv_cnt == 0 ||
2730 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
2731 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
2732 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
2733 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
2734 else
2735 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
2736 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
2737 if (error)
2738 panic("buf_vlist_add: Preallocated nodes insufficient.");
2739 bv->bv_cnt++;
2740 }
2741
2742 /*
2743 * Look up a buffer using the buffer tries.
2744 */
2745 struct buf *
gbincore(struct bufobj * bo,daddr_t lblkno)2746 gbincore(struct bufobj *bo, daddr_t lblkno)
2747 {
2748 struct buf *bp;
2749
2750 ASSERT_BO_LOCKED(bo);
2751 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
2752 if (bp != NULL)
2753 return (bp);
2754 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno));
2755 }
2756
2757 /*
2758 * Look up a buf using the buffer tries, without the bufobj lock. This relies
2759 * on SMR for safe lookup, and bufs being in a no-free zone to provide type
2760 * stability of the result. Like other lockless lookups, the found buf may
2761 * already be invalid by the time this function returns.
2762 */
2763 struct buf *
gbincore_unlocked(struct bufobj * bo,daddr_t lblkno)2764 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno)
2765 {
2766 struct buf *bp;
2767
2768 ASSERT_BO_UNLOCKED(bo);
2769 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno);
2770 if (bp != NULL)
2771 return (bp);
2772 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno));
2773 }
2774
2775 /*
2776 * Associate a buffer with a vnode.
2777 */
2778 void
bgetvp(struct vnode * vp,struct buf * bp)2779 bgetvp(struct vnode *vp, struct buf *bp)
2780 {
2781 struct bufobj *bo;
2782
2783 bo = &vp->v_bufobj;
2784 ASSERT_BO_WLOCKED(bo);
2785 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
2786
2787 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
2788 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
2789 ("bgetvp: bp already attached! %p", bp));
2790
2791 vhold(vp);
2792 bp->b_vp = vp;
2793 bp->b_bufobj = bo;
2794 /*
2795 * Insert onto list for new vnode.
2796 */
2797 buf_vlist_add(bp, bo, BX_VNCLEAN);
2798 }
2799
2800 /*
2801 * Disassociate a buffer from a vnode.
2802 */
2803 void
brelvp(struct buf * bp)2804 brelvp(struct buf *bp)
2805 {
2806 struct bufobj *bo;
2807 struct vnode *vp;
2808
2809 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
2810 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
2811
2812 /*
2813 * Delete from old vnode list, if on one.
2814 */
2815 vp = bp->b_vp; /* XXX */
2816 bo = bp->b_bufobj;
2817 BO_LOCK(bo);
2818 buf_vlist_remove(bp);
2819 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2820 bo->bo_flag &= ~BO_ONWORKLST;
2821 mtx_lock(&sync_mtx);
2822 LIST_REMOVE(bo, bo_synclist);
2823 syncer_worklist_len--;
2824 mtx_unlock(&sync_mtx);
2825 }
2826 bp->b_vp = NULL;
2827 bp->b_bufobj = NULL;
2828 BO_UNLOCK(bo);
2829 vdrop(vp);
2830 }
2831
2832 /*
2833 * Add an item to the syncer work queue.
2834 */
2835 static void
vn_syncer_add_to_worklist(struct bufobj * bo,int delay)2836 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2837 {
2838 int slot;
2839
2840 ASSERT_BO_WLOCKED(bo);
2841
2842 mtx_lock(&sync_mtx);
2843 if (bo->bo_flag & BO_ONWORKLST)
2844 LIST_REMOVE(bo, bo_synclist);
2845 else {
2846 bo->bo_flag |= BO_ONWORKLST;
2847 syncer_worklist_len++;
2848 }
2849
2850 if (delay > syncer_maxdelay - 2)
2851 delay = syncer_maxdelay - 2;
2852 slot = (syncer_delayno + delay) & syncer_mask;
2853
2854 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2855 mtx_unlock(&sync_mtx);
2856 }
2857
2858 static int
sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)2859 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2860 {
2861 int error, len;
2862
2863 mtx_lock(&sync_mtx);
2864 len = syncer_worklist_len - sync_vnode_count;
2865 mtx_unlock(&sync_mtx);
2866 error = SYSCTL_OUT(req, &len, sizeof(len));
2867 return (error);
2868 }
2869
2870 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len,
2871 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0,
2872 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2873
2874 static struct proc *updateproc;
2875 static void sched_sync(void);
2876 static struct kproc_desc up_kp = {
2877 "syncer",
2878 sched_sync,
2879 &updateproc
2880 };
2881 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2882
2883 static int
sync_vnode(struct synclist * slp,struct bufobj ** bo,struct thread * td)2884 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2885 {
2886 struct vnode *vp;
2887 struct mount *mp;
2888
2889 *bo = LIST_FIRST(slp);
2890 if (*bo == NULL)
2891 return (0);
2892 vp = bo2vnode(*bo);
2893 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2894 return (1);
2895 /*
2896 * We use vhold in case the vnode does not
2897 * successfully sync. vhold prevents the vnode from
2898 * going away when we unlock the sync_mtx so that
2899 * we can acquire the vnode interlock.
2900 */
2901 vholdl(vp);
2902 mtx_unlock(&sync_mtx);
2903 VI_UNLOCK(vp);
2904 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2905 vdrop(vp);
2906 mtx_lock(&sync_mtx);
2907 return (*bo == LIST_FIRST(slp));
2908 }
2909 MPASSERT(mp == NULL || (curthread->td_pflags & TDP_IGNSUSP) != 0 ||
2910 (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0, mp,
2911 ("suspended mp syncing vp %p", vp));
2912 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2913 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2914 VOP_UNLOCK(vp);
2915 vn_finished_write(mp);
2916 BO_LOCK(*bo);
2917 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2918 /*
2919 * Put us back on the worklist. The worklist
2920 * routine will remove us from our current
2921 * position and then add us back in at a later
2922 * position.
2923 */
2924 vn_syncer_add_to_worklist(*bo, syncdelay);
2925 }
2926 BO_UNLOCK(*bo);
2927 vdrop(vp);
2928 mtx_lock(&sync_mtx);
2929 return (0);
2930 }
2931
2932 static int first_printf = 1;
2933
2934 /*
2935 * System filesystem synchronizer daemon.
2936 */
2937 static void
sched_sync(void)2938 sched_sync(void)
2939 {
2940 struct synclist *next, *slp;
2941 struct bufobj *bo;
2942 long starttime;
2943 struct thread *td = curthread;
2944 int last_work_seen;
2945 int net_worklist_len;
2946 int syncer_final_iter;
2947 int error;
2948
2949 last_work_seen = 0;
2950 syncer_final_iter = 0;
2951 syncer_state = SYNCER_RUNNING;
2952 starttime = time_uptime;
2953 td->td_pflags |= TDP_NORUNNINGBUF;
2954
2955 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
2956 SHUTDOWN_PRI_LAST);
2957
2958 mtx_lock(&sync_mtx);
2959 for (;;) {
2960 if (syncer_state == SYNCER_FINAL_DELAY &&
2961 syncer_final_iter == 0) {
2962 mtx_unlock(&sync_mtx);
2963 kproc_suspend_check(td->td_proc);
2964 mtx_lock(&sync_mtx);
2965 }
2966 net_worklist_len = syncer_worklist_len - sync_vnode_count;
2967 if (syncer_state != SYNCER_RUNNING &&
2968 starttime != time_uptime) {
2969 if (first_printf) {
2970 printf("\nSyncing disks, vnodes remaining... ");
2971 first_printf = 0;
2972 }
2973 printf("%d ", net_worklist_len);
2974 }
2975 starttime = time_uptime;
2976
2977 /*
2978 * Push files whose dirty time has expired. Be careful
2979 * of interrupt race on slp queue.
2980 *
2981 * Skip over empty worklist slots when shutting down.
2982 */
2983 do {
2984 slp = &syncer_workitem_pending[syncer_delayno];
2985 syncer_delayno += 1;
2986 if (syncer_delayno == syncer_maxdelay)
2987 syncer_delayno = 0;
2988 next = &syncer_workitem_pending[syncer_delayno];
2989 /*
2990 * If the worklist has wrapped since the
2991 * it was emptied of all but syncer vnodes,
2992 * switch to the FINAL_DELAY state and run
2993 * for one more second.
2994 */
2995 if (syncer_state == SYNCER_SHUTTING_DOWN &&
2996 net_worklist_len == 0 &&
2997 last_work_seen == syncer_delayno) {
2998 syncer_state = SYNCER_FINAL_DELAY;
2999 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
3000 }
3001 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
3002 syncer_worklist_len > 0);
3003
3004 /*
3005 * Keep track of the last time there was anything
3006 * on the worklist other than syncer vnodes.
3007 * Return to the SHUTTING_DOWN state if any
3008 * new work appears.
3009 */
3010 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
3011 last_work_seen = syncer_delayno;
3012 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
3013 syncer_state = SYNCER_SHUTTING_DOWN;
3014 while (!LIST_EMPTY(slp)) {
3015 error = sync_vnode(slp, &bo, td);
3016 if (error == 1) {
3017 LIST_REMOVE(bo, bo_synclist);
3018 LIST_INSERT_HEAD(next, bo, bo_synclist);
3019 continue;
3020 }
3021
3022 if (first_printf == 0) {
3023 /*
3024 * Drop the sync mutex, because some watchdog
3025 * drivers need to sleep while patting
3026 */
3027 mtx_unlock(&sync_mtx);
3028 wdog_kern_pat(WD_LASTVAL);
3029 mtx_lock(&sync_mtx);
3030 }
3031 }
3032 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
3033 syncer_final_iter--;
3034 /*
3035 * The variable rushjob allows the kernel to speed up the
3036 * processing of the filesystem syncer process. A rushjob
3037 * value of N tells the filesystem syncer to process the next
3038 * N seconds worth of work on its queue ASAP. Currently rushjob
3039 * is used by the soft update code to speed up the filesystem
3040 * syncer process when the incore state is getting so far
3041 * ahead of the disk that the kernel memory pool is being
3042 * threatened with exhaustion.
3043 */
3044 if (rushjob > 0) {
3045 rushjob -= 1;
3046 continue;
3047 }
3048 /*
3049 * Just sleep for a short period of time between
3050 * iterations when shutting down to allow some I/O
3051 * to happen.
3052 *
3053 * If it has taken us less than a second to process the
3054 * current work, then wait. Otherwise start right over
3055 * again. We can still lose time if any single round
3056 * takes more than two seconds, but it does not really
3057 * matter as we are just trying to generally pace the
3058 * filesystem activity.
3059 */
3060 if (syncer_state != SYNCER_RUNNING ||
3061 time_uptime == starttime) {
3062 thread_lock(td);
3063 sched_prio(td, PPAUSE);
3064 thread_unlock(td);
3065 }
3066 if (syncer_state != SYNCER_RUNNING)
3067 cv_timedwait(&sync_wakeup, &sync_mtx,
3068 hz / SYNCER_SHUTDOWN_SPEEDUP);
3069 else if (time_uptime == starttime)
3070 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
3071 }
3072 }
3073
3074 /*
3075 * Request the syncer daemon to speed up its work.
3076 * We never push it to speed up more than half of its
3077 * normal turn time, otherwise it could take over the cpu.
3078 */
3079 int
speedup_syncer(void)3080 speedup_syncer(void)
3081 {
3082 int ret = 0;
3083
3084 mtx_lock(&sync_mtx);
3085 if (rushjob < syncdelay / 2) {
3086 rushjob += 1;
3087 stat_rush_requests += 1;
3088 ret = 1;
3089 }
3090 mtx_unlock(&sync_mtx);
3091 cv_broadcast(&sync_wakeup);
3092 return (ret);
3093 }
3094
3095 /*
3096 * Tell the syncer to speed up its work and run though its work
3097 * list several times, then tell it to shut down.
3098 */
3099 static void
syncer_shutdown(void * arg,int howto)3100 syncer_shutdown(void *arg, int howto)
3101 {
3102
3103 if (howto & RB_NOSYNC)
3104 return;
3105 mtx_lock(&sync_mtx);
3106 syncer_state = SYNCER_SHUTTING_DOWN;
3107 rushjob = 0;
3108 mtx_unlock(&sync_mtx);
3109 cv_broadcast(&sync_wakeup);
3110 kproc_shutdown(arg, howto);
3111 }
3112
3113 void
syncer_suspend(void)3114 syncer_suspend(void)
3115 {
3116
3117 syncer_shutdown(updateproc, 0);
3118 }
3119
3120 void
syncer_resume(void)3121 syncer_resume(void)
3122 {
3123
3124 mtx_lock(&sync_mtx);
3125 first_printf = 1;
3126 syncer_state = SYNCER_RUNNING;
3127 mtx_unlock(&sync_mtx);
3128 cv_broadcast(&sync_wakeup);
3129 kproc_resume(updateproc);
3130 }
3131
3132 /*
3133 * Move the buffer between the clean and dirty lists of its vnode.
3134 */
3135 void
reassignbuf(struct buf * bp)3136 reassignbuf(struct buf *bp)
3137 {
3138 struct vnode *vp;
3139 struct bufobj *bo;
3140 int delay;
3141 #ifdef INVARIANTS
3142 struct bufv *bv;
3143 #endif
3144
3145 vp = bp->b_vp;
3146 bo = bp->b_bufobj;
3147
3148 KASSERT((bp->b_flags & B_PAGING) == 0,
3149 ("%s: cannot reassign paging buffer %p", __func__, bp));
3150
3151 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
3152 bp, bp->b_vp, bp->b_flags);
3153
3154 BO_LOCK(bo);
3155 buf_vlist_remove(bp);
3156
3157 /*
3158 * If dirty, put on list of dirty buffers; otherwise insert onto list
3159 * of clean buffers.
3160 */
3161 if (bp->b_flags & B_DELWRI) {
3162 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
3163 switch (vp->v_type) {
3164 case VDIR:
3165 delay = dirdelay;
3166 break;
3167 case VCHR:
3168 delay = metadelay;
3169 break;
3170 default:
3171 delay = filedelay;
3172 }
3173 vn_syncer_add_to_worklist(bo, delay);
3174 }
3175 buf_vlist_add(bp, bo, BX_VNDIRTY);
3176 } else {
3177 buf_vlist_add(bp, bo, BX_VNCLEAN);
3178
3179 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
3180 mtx_lock(&sync_mtx);
3181 LIST_REMOVE(bo, bo_synclist);
3182 syncer_worklist_len--;
3183 mtx_unlock(&sync_mtx);
3184 bo->bo_flag &= ~BO_ONWORKLST;
3185 }
3186 }
3187 #ifdef INVARIANTS
3188 bv = &bo->bo_clean;
3189 bp = TAILQ_FIRST(&bv->bv_hd);
3190 KASSERT(bp == NULL || bp->b_bufobj == bo,
3191 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3192 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3193 KASSERT(bp == NULL || bp->b_bufobj == bo,
3194 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3195 bv = &bo->bo_dirty;
3196 bp = TAILQ_FIRST(&bv->bv_hd);
3197 KASSERT(bp == NULL || bp->b_bufobj == bo,
3198 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3199 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3200 KASSERT(bp == NULL || bp->b_bufobj == bo,
3201 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3202 #endif
3203 BO_UNLOCK(bo);
3204 }
3205
3206 static void
v_init_counters(struct vnode * vp)3207 v_init_counters(struct vnode *vp)
3208 {
3209
3210 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
3211 vp, ("%s called for an initialized vnode", __FUNCTION__));
3212 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
3213
3214 refcount_init(&vp->v_holdcnt, 1);
3215 refcount_init(&vp->v_usecount, 1);
3216 }
3217
3218 /*
3219 * Get a usecount on a vnode.
3220 *
3221 * vget and vget_finish may fail to lock the vnode if they lose a race against
3222 * it being doomed. LK_RETRY can be passed in flags to lock it anyway.
3223 *
3224 * Consumers which don't guarantee liveness of the vnode can use SMR to
3225 * try to get a reference. Note this operation can fail since the vnode
3226 * may be awaiting getting freed by the time they get to it.
3227 */
3228 enum vgetstate
vget_prep_smr(struct vnode * vp)3229 vget_prep_smr(struct vnode *vp)
3230 {
3231 enum vgetstate vs;
3232
3233 VFS_SMR_ASSERT_ENTERED();
3234
3235 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3236 vs = VGET_USECOUNT;
3237 } else {
3238 if (vhold_smr(vp))
3239 vs = VGET_HOLDCNT;
3240 else
3241 vs = VGET_NONE;
3242 }
3243 return (vs);
3244 }
3245
3246 enum vgetstate
vget_prep(struct vnode * vp)3247 vget_prep(struct vnode *vp)
3248 {
3249 enum vgetstate vs;
3250
3251 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3252 vs = VGET_USECOUNT;
3253 } else {
3254 vhold(vp);
3255 vs = VGET_HOLDCNT;
3256 }
3257 return (vs);
3258 }
3259
3260 void
vget_abort(struct vnode * vp,enum vgetstate vs)3261 vget_abort(struct vnode *vp, enum vgetstate vs)
3262 {
3263
3264 switch (vs) {
3265 case VGET_USECOUNT:
3266 vrele(vp);
3267 break;
3268 case VGET_HOLDCNT:
3269 vdrop(vp);
3270 break;
3271 default:
3272 __assert_unreachable();
3273 }
3274 }
3275
3276 int
vget(struct vnode * vp,int flags)3277 vget(struct vnode *vp, int flags)
3278 {
3279 enum vgetstate vs;
3280
3281 vs = vget_prep(vp);
3282 return (vget_finish(vp, flags, vs));
3283 }
3284
3285 int
vget_finish(struct vnode * vp,int flags,enum vgetstate vs)3286 vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
3287 {
3288 int error;
3289
3290 if ((flags & LK_INTERLOCK) != 0)
3291 ASSERT_VI_LOCKED(vp, __func__);
3292 else
3293 ASSERT_VI_UNLOCKED(vp, __func__);
3294 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3295 VNPASS(vp->v_holdcnt > 0, vp);
3296 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3297
3298 error = vn_lock(vp, flags);
3299 if (__predict_false(error != 0)) {
3300 vget_abort(vp, vs);
3301 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
3302 vp);
3303 return (error);
3304 }
3305
3306 vget_finish_ref(vp, vs);
3307 return (0);
3308 }
3309
3310 void
vget_finish_ref(struct vnode * vp,enum vgetstate vs)3311 vget_finish_ref(struct vnode *vp, enum vgetstate vs)
3312 {
3313 int old;
3314
3315 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3316 VNPASS(vp->v_holdcnt > 0, vp);
3317 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3318
3319 if (vs == VGET_USECOUNT)
3320 return;
3321
3322 /*
3323 * We hold the vnode. If the usecount is 0 it will be utilized to keep
3324 * the vnode around. Otherwise someone else lended their hold count and
3325 * we have to drop ours.
3326 */
3327 old = atomic_fetchadd_int(&vp->v_usecount, 1);
3328 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old));
3329 if (old != 0) {
3330 #ifdef INVARIANTS
3331 old = atomic_fetchadd_int(&vp->v_holdcnt, -1);
3332 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old));
3333 #else
3334 refcount_release(&vp->v_holdcnt);
3335 #endif
3336 }
3337 }
3338
3339 void
vref(struct vnode * vp)3340 vref(struct vnode *vp)
3341 {
3342 enum vgetstate vs;
3343
3344 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3345 vs = vget_prep(vp);
3346 vget_finish_ref(vp, vs);
3347 }
3348
3349 void
vrefact(struct vnode * vp)3350 vrefact(struct vnode *vp)
3351 {
3352 int old __diagused;
3353
3354 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3355 old = refcount_acquire(&vp->v_usecount);
3356 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old));
3357 }
3358
3359 void
vlazy(struct vnode * vp)3360 vlazy(struct vnode *vp)
3361 {
3362 struct mount *mp;
3363
3364 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__));
3365
3366 if ((vp->v_mflag & VMP_LAZYLIST) != 0)
3367 return;
3368 /*
3369 * We may get here for inactive routines after the vnode got doomed.
3370 */
3371 if (VN_IS_DOOMED(vp))
3372 return;
3373 mp = vp->v_mount;
3374 mtx_lock(&mp->mnt_listmtx);
3375 if ((vp->v_mflag & VMP_LAZYLIST) == 0) {
3376 vp->v_mflag |= VMP_LAZYLIST;
3377 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3378 mp->mnt_lazyvnodelistsize++;
3379 }
3380 mtx_unlock(&mp->mnt_listmtx);
3381 }
3382
3383 static void
vunlazy(struct vnode * vp)3384 vunlazy(struct vnode *vp)
3385 {
3386 struct mount *mp;
3387
3388 ASSERT_VI_LOCKED(vp, __func__);
3389 VNPASS(!VN_IS_DOOMED(vp), vp);
3390
3391 mp = vp->v_mount;
3392 mtx_lock(&mp->mnt_listmtx);
3393 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3394 /*
3395 * Don't remove the vnode from the lazy list if another thread
3396 * has increased the hold count. It may have re-enqueued the
3397 * vnode to the lazy list and is now responsible for its
3398 * removal.
3399 */
3400 if (vp->v_holdcnt == 0) {
3401 vp->v_mflag &= ~VMP_LAZYLIST;
3402 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3403 mp->mnt_lazyvnodelistsize--;
3404 }
3405 mtx_unlock(&mp->mnt_listmtx);
3406 }
3407
3408 /*
3409 * This routine is only meant to be called from vgonel prior to dooming
3410 * the vnode.
3411 */
3412 static void
vunlazy_gone(struct vnode * vp)3413 vunlazy_gone(struct vnode *vp)
3414 {
3415 struct mount *mp;
3416
3417 ASSERT_VOP_ELOCKED(vp, __func__);
3418 ASSERT_VI_LOCKED(vp, __func__);
3419 VNPASS(!VN_IS_DOOMED(vp), vp);
3420
3421 if (vp->v_mflag & VMP_LAZYLIST) {
3422 mp = vp->v_mount;
3423 mtx_lock(&mp->mnt_listmtx);
3424 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3425 vp->v_mflag &= ~VMP_LAZYLIST;
3426 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3427 mp->mnt_lazyvnodelistsize--;
3428 mtx_unlock(&mp->mnt_listmtx);
3429 }
3430 }
3431
3432 static void
vdefer_inactive(struct vnode * vp)3433 vdefer_inactive(struct vnode *vp)
3434 {
3435
3436 ASSERT_VI_LOCKED(vp, __func__);
3437 VNPASS(vp->v_holdcnt > 0, vp);
3438 if (VN_IS_DOOMED(vp)) {
3439 vdropl(vp);
3440 return;
3441 }
3442 if (vp->v_iflag & VI_DEFINACT) {
3443 VNPASS(vp->v_holdcnt > 1, vp);
3444 vdropl(vp);
3445 return;
3446 }
3447 if (vp->v_usecount > 0) {
3448 vp->v_iflag &= ~VI_OWEINACT;
3449 vdropl(vp);
3450 return;
3451 }
3452 vlazy(vp);
3453 vp->v_iflag |= VI_DEFINACT;
3454 VI_UNLOCK(vp);
3455 atomic_add_long(&deferred_inact, 1);
3456 }
3457
3458 static void
vdefer_inactive_unlocked(struct vnode * vp)3459 vdefer_inactive_unlocked(struct vnode *vp)
3460 {
3461
3462 VI_LOCK(vp);
3463 if ((vp->v_iflag & VI_OWEINACT) == 0) {
3464 vdropl(vp);
3465 return;
3466 }
3467 vdefer_inactive(vp);
3468 }
3469
3470 enum vput_op { VRELE, VPUT, VUNREF };
3471
3472 /*
3473 * Handle ->v_usecount transitioning to 0.
3474 *
3475 * By releasing the last usecount we take ownership of the hold count which
3476 * provides liveness of the vnode, meaning we have to vdrop.
3477 *
3478 * For all vnodes we may need to perform inactive processing. It requires an
3479 * exclusive lock on the vnode, while it is legal to call here with only a
3480 * shared lock (or no locks). If locking the vnode in an expected manner fails,
3481 * inactive processing gets deferred to the syncer.
3482 *
3483 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend
3484 * on the lock being held all the way until VOP_INACTIVE. This in particular
3485 * happens with UFS which adds half-constructed vnodes to the hash, where they
3486 * can be found by other code.
3487 */
3488 static void
vput_final(struct vnode * vp,enum vput_op func)3489 vput_final(struct vnode *vp, enum vput_op func)
3490 {
3491 int error;
3492 bool want_unlock;
3493
3494 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3495 VNPASS(vp->v_holdcnt > 0, vp);
3496
3497 VI_LOCK(vp);
3498
3499 /*
3500 * By the time we got here someone else might have transitioned
3501 * the count back to > 0.
3502 */
3503 if (vp->v_usecount > 0)
3504 goto out;
3505
3506 /*
3507 * If the vnode is doomed vgone already performed inactive processing
3508 * (if needed).
3509 */
3510 if (VN_IS_DOOMED(vp))
3511 goto out;
3512
3513 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0))
3514 goto out;
3515
3516 if (vp->v_iflag & VI_DOINGINACT)
3517 goto out;
3518
3519 /*
3520 * Locking operations here will drop the interlock and possibly the
3521 * vnode lock, opening a window where the vnode can get doomed all the
3522 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to
3523 * perform inactive.
3524 */
3525 vp->v_iflag |= VI_OWEINACT;
3526 want_unlock = false;
3527 error = 0;
3528 switch (func) {
3529 case VRELE:
3530 switch (VOP_ISLOCKED(vp)) {
3531 case LK_EXCLUSIVE:
3532 break;
3533 case LK_EXCLOTHER:
3534 case 0:
3535 want_unlock = true;
3536 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
3537 VI_LOCK(vp);
3538 break;
3539 default:
3540 /*
3541 * The lock has at least one sharer, but we have no way
3542 * to conclude whether this is us. Play it safe and
3543 * defer processing.
3544 */
3545 error = EAGAIN;
3546 break;
3547 }
3548 break;
3549 case VPUT:
3550 want_unlock = true;
3551 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3552 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
3553 LK_NOWAIT);
3554 VI_LOCK(vp);
3555 }
3556 break;
3557 case VUNREF:
3558 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3559 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
3560 VI_LOCK(vp);
3561 }
3562 break;
3563 }
3564 if (error == 0) {
3565 if (func == VUNREF) {
3566 VNASSERT((vp->v_vflag & VV_UNREF) == 0, vp,
3567 ("recursive vunref"));
3568 vp->v_vflag |= VV_UNREF;
3569 }
3570 for (;;) {
3571 error = vinactive(vp);
3572 if (want_unlock)
3573 VOP_UNLOCK(vp);
3574 if (error != ERELOOKUP || !want_unlock)
3575 break;
3576 VOP_LOCK(vp, LK_EXCLUSIVE);
3577 }
3578 if (func == VUNREF)
3579 vp->v_vflag &= ~VV_UNREF;
3580 vdropl(vp);
3581 } else {
3582 vdefer_inactive(vp);
3583 }
3584 return;
3585 out:
3586 if (func == VPUT)
3587 VOP_UNLOCK(vp);
3588 vdropl(vp);
3589 }
3590
3591 /*
3592 * Decrement ->v_usecount for a vnode.
3593 *
3594 * Releasing the last use count requires additional processing, see vput_final
3595 * above for details.
3596 *
3597 * Comment above each variant denotes lock state on entry and exit.
3598 */
3599
3600 /*
3601 * in: any
3602 * out: same as passed in
3603 */
3604 void
vrele(struct vnode * vp)3605 vrele(struct vnode *vp)
3606 {
3607
3608 ASSERT_VI_UNLOCKED(vp, __func__);
3609 if (!refcount_release(&vp->v_usecount))
3610 return;
3611 vput_final(vp, VRELE);
3612 }
3613
3614 /*
3615 * in: locked
3616 * out: unlocked
3617 */
3618 void
vput(struct vnode * vp)3619 vput(struct vnode *vp)
3620 {
3621
3622 ASSERT_VOP_LOCKED(vp, __func__);
3623 ASSERT_VI_UNLOCKED(vp, __func__);
3624 if (!refcount_release(&vp->v_usecount)) {
3625 VOP_UNLOCK(vp);
3626 return;
3627 }
3628 vput_final(vp, VPUT);
3629 }
3630
3631 /*
3632 * in: locked
3633 * out: locked
3634 */
3635 void
vunref(struct vnode * vp)3636 vunref(struct vnode *vp)
3637 {
3638
3639 ASSERT_VOP_LOCKED(vp, __func__);
3640 ASSERT_VI_UNLOCKED(vp, __func__);
3641 if (!refcount_release(&vp->v_usecount))
3642 return;
3643 vput_final(vp, VUNREF);
3644 }
3645
3646 void
vhold(struct vnode * vp)3647 vhold(struct vnode *vp)
3648 {
3649 int old;
3650
3651 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3652 old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3653 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3654 ("%s: wrong hold count %d", __func__, old));
3655 if (old == 0)
3656 vfs_freevnodes_dec();
3657 }
3658
3659 void
vholdnz(struct vnode * vp)3660 vholdnz(struct vnode *vp)
3661 {
3662
3663 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3664 #ifdef INVARIANTS
3665 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3666 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3667 ("%s: wrong hold count %d", __func__, old));
3668 #else
3669 atomic_add_int(&vp->v_holdcnt, 1);
3670 #endif
3671 }
3672
3673 /*
3674 * Grab a hold count unless the vnode is freed.
3675 *
3676 * Only use this routine if vfs smr is the only protection you have against
3677 * freeing the vnode.
3678 *
3679 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag
3680 * is not set. After the flag is set the vnode becomes immutable to anyone but
3681 * the thread which managed to set the flag.
3682 *
3683 * It may be tempting to replace the loop with:
3684 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3685 * if (count & VHOLD_NO_SMR) {
3686 * backpedal and error out;
3687 * }
3688 *
3689 * However, while this is more performant, it hinders debugging by eliminating
3690 * the previously mentioned invariant.
3691 */
3692 bool
vhold_smr(struct vnode * vp)3693 vhold_smr(struct vnode *vp)
3694 {
3695 int count;
3696
3697 VFS_SMR_ASSERT_ENTERED();
3698
3699 count = atomic_load_int(&vp->v_holdcnt);
3700 for (;;) {
3701 if (count & VHOLD_NO_SMR) {
3702 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3703 ("non-zero hold count with flags %d\n", count));
3704 return (false);
3705 }
3706 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3707 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3708 if (count == 0)
3709 vfs_freevnodes_dec();
3710 return (true);
3711 }
3712 }
3713 }
3714
3715 /*
3716 * Hold a free vnode for recycling.
3717 *
3718 * Note: vnode_init references this comment.
3719 *
3720 * Attempts to recycle only need the global vnode list lock and have no use for
3721 * SMR.
3722 *
3723 * However, vnodes get inserted into the global list before they get fully
3724 * initialized and stay there until UMA decides to free the memory. This in
3725 * particular means the target can be found before it becomes usable and after
3726 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to
3727 * VHOLD_NO_SMR.
3728 *
3729 * Note: the vnode may gain more references after we transition the count 0->1.
3730 */
3731 static bool
vhold_recycle_free(struct vnode * vp)3732 vhold_recycle_free(struct vnode *vp)
3733 {
3734 int count;
3735
3736 mtx_assert(&vnode_list_mtx, MA_OWNED);
3737
3738 count = atomic_load_int(&vp->v_holdcnt);
3739 for (;;) {
3740 if (count & VHOLD_NO_SMR) {
3741 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3742 ("non-zero hold count with flags %d\n", count));
3743 return (false);
3744 }
3745 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3746 if (count > 0) {
3747 return (false);
3748 }
3749 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3750 vfs_freevnodes_dec();
3751 return (true);
3752 }
3753 }
3754 }
3755
3756 static void __noinline
vdbatch_process(struct vdbatch * vd)3757 vdbatch_process(struct vdbatch *vd)
3758 {
3759 struct vnode *vp;
3760 int i;
3761
3762 mtx_assert(&vd->lock, MA_OWNED);
3763 MPASS(curthread->td_pinned > 0);
3764 MPASS(vd->index == VDBATCH_SIZE);
3765
3766 /*
3767 * Attempt to requeue the passed batch, but give up easily.
3768 *
3769 * Despite batching the mechanism is prone to transient *significant*
3770 * lock contention, where vnode_list_mtx becomes the primary bottleneck
3771 * if multiple CPUs get here (one real-world example is highly parallel
3772 * do-nothing make , which will stat *tons* of vnodes). Since it is
3773 * quasi-LRU (read: not that great even if fully honoured) just dodge
3774 * the problem. Parties which don't like it are welcome to implement
3775 * something better.
3776 */
3777 critical_enter();
3778 if (mtx_trylock(&vnode_list_mtx)) {
3779 for (i = 0; i < VDBATCH_SIZE; i++) {
3780 vp = vd->tab[i];
3781 vd->tab[i] = NULL;
3782 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
3783 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist);
3784 MPASS(vp->v_dbatchcpu != NOCPU);
3785 vp->v_dbatchcpu = NOCPU;
3786 }
3787 mtx_unlock(&vnode_list_mtx);
3788 } else {
3789 counter_u64_add(vnode_skipped_requeues, 1);
3790
3791 for (i = 0; i < VDBATCH_SIZE; i++) {
3792 vp = vd->tab[i];
3793 vd->tab[i] = NULL;
3794 MPASS(vp->v_dbatchcpu != NOCPU);
3795 vp->v_dbatchcpu = NOCPU;
3796 }
3797 }
3798 vd->index = 0;
3799 critical_exit();
3800 }
3801
3802 static void
vdbatch_enqueue(struct vnode * vp)3803 vdbatch_enqueue(struct vnode *vp)
3804 {
3805 struct vdbatch *vd;
3806
3807 ASSERT_VI_LOCKED(vp, __func__);
3808 VNPASS(!VN_IS_DOOMED(vp), vp);
3809
3810 if (vp->v_dbatchcpu != NOCPU) {
3811 VI_UNLOCK(vp);
3812 return;
3813 }
3814
3815 sched_pin();
3816 vd = DPCPU_PTR(vd);
3817 mtx_lock(&vd->lock);
3818 MPASS(vd->index < VDBATCH_SIZE);
3819 MPASS(vd->tab[vd->index] == NULL);
3820 /*
3821 * A hack: we depend on being pinned so that we know what to put in
3822 * ->v_dbatchcpu.
3823 */
3824 vp->v_dbatchcpu = curcpu;
3825 vd->tab[vd->index] = vp;
3826 vd->index++;
3827 VI_UNLOCK(vp);
3828 if (vd->index == VDBATCH_SIZE)
3829 vdbatch_process(vd);
3830 mtx_unlock(&vd->lock);
3831 sched_unpin();
3832 }
3833
3834 /*
3835 * This routine must only be called for vnodes which are about to be
3836 * deallocated. Supporting dequeue for arbitrary vndoes would require
3837 * validating that the locked batch matches.
3838 */
3839 static void
vdbatch_dequeue(struct vnode * vp)3840 vdbatch_dequeue(struct vnode *vp)
3841 {
3842 struct vdbatch *vd;
3843 int i;
3844 short cpu;
3845
3846 VNPASS(vp->v_type == VBAD || vp->v_type == VNON, vp);
3847
3848 cpu = vp->v_dbatchcpu;
3849 if (cpu == NOCPU)
3850 return;
3851
3852 vd = DPCPU_ID_PTR(cpu, vd);
3853 mtx_lock(&vd->lock);
3854 for (i = 0; i < vd->index; i++) {
3855 if (vd->tab[i] != vp)
3856 continue;
3857 vp->v_dbatchcpu = NOCPU;
3858 vd->index--;
3859 vd->tab[i] = vd->tab[vd->index];
3860 vd->tab[vd->index] = NULL;
3861 break;
3862 }
3863 mtx_unlock(&vd->lock);
3864 /*
3865 * Either we dequeued the vnode above or the target CPU beat us to it.
3866 */
3867 MPASS(vp->v_dbatchcpu == NOCPU);
3868 }
3869
3870 /*
3871 * Drop the hold count of the vnode.
3872 *
3873 * It will only get freed if this is the last hold *and* it has been vgone'd.
3874 *
3875 * Because the vnode vm object keeps a hold reference on the vnode if
3876 * there is at least one resident non-cached page, the vnode cannot
3877 * leave the active list without the page cleanup done.
3878 */
3879 static void __noinline
vdropl_final(struct vnode * vp)3880 vdropl_final(struct vnode *vp)
3881 {
3882
3883 ASSERT_VI_LOCKED(vp, __func__);
3884 VNPASS(VN_IS_DOOMED(vp), vp);
3885 /*
3886 * Set the VHOLD_NO_SMR flag.
3887 *
3888 * We may be racing against vhold_smr. If they win we can just pretend
3889 * we never got this far, they will vdrop later.
3890 */
3891 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) {
3892 vfs_freevnodes_inc();
3893 VI_UNLOCK(vp);
3894 /*
3895 * We lost the aforementioned race. Any subsequent access is
3896 * invalid as they might have managed to vdropl on their own.
3897 */
3898 return;
3899 }
3900 /*
3901 * Don't bump freevnodes as this one is going away.
3902 */
3903 freevnode(vp);
3904 }
3905
3906 void
vdrop(struct vnode * vp)3907 vdrop(struct vnode *vp)
3908 {
3909
3910 ASSERT_VI_UNLOCKED(vp, __func__);
3911 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3912 if (refcount_release_if_not_last(&vp->v_holdcnt))
3913 return;
3914 VI_LOCK(vp);
3915 vdropl(vp);
3916 }
3917
3918 static void __always_inline
vdropl_impl(struct vnode * vp,bool enqueue)3919 vdropl_impl(struct vnode *vp, bool enqueue)
3920 {
3921
3922 ASSERT_VI_LOCKED(vp, __func__);
3923 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3924 if (!refcount_release(&vp->v_holdcnt)) {
3925 VI_UNLOCK(vp);
3926 return;
3927 }
3928 VNPASS((vp->v_iflag & VI_OWEINACT) == 0, vp);
3929 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
3930 if (VN_IS_DOOMED(vp)) {
3931 vdropl_final(vp);
3932 return;
3933 }
3934
3935 vfs_freevnodes_inc();
3936 if (vp->v_mflag & VMP_LAZYLIST) {
3937 vunlazy(vp);
3938 }
3939
3940 if (!enqueue) {
3941 VI_UNLOCK(vp);
3942 return;
3943 }
3944
3945 /*
3946 * Also unlocks the interlock. We can't assert on it as we
3947 * released our hold and by now the vnode might have been
3948 * freed.
3949 */
3950 vdbatch_enqueue(vp);
3951 }
3952
3953 void
vdropl(struct vnode * vp)3954 vdropl(struct vnode *vp)
3955 {
3956
3957 vdropl_impl(vp, true);
3958 }
3959
3960 /*
3961 * vdrop a vnode when recycling
3962 *
3963 * This is a special case routine only to be used when recycling, differs from
3964 * regular vdrop by not requeieing the vnode on LRU.
3965 *
3966 * Consider a case where vtryrecycle continuously fails with all vnodes (due to
3967 * e.g., frozen writes on the filesystem), filling the batch and causing it to
3968 * be requeued. Then vnlru will end up revisiting the same vnodes. This is a
3969 * loop which can last for as long as writes are frozen.
3970 */
3971 static void
vdropl_recycle(struct vnode * vp)3972 vdropl_recycle(struct vnode *vp)
3973 {
3974
3975 vdropl_impl(vp, false);
3976 }
3977
3978 static void
vdrop_recycle(struct vnode * vp)3979 vdrop_recycle(struct vnode *vp)
3980 {
3981
3982 VI_LOCK(vp);
3983 vdropl_recycle(vp);
3984 }
3985
3986 /*
3987 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
3988 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
3989 */
3990 static int
vinactivef(struct vnode * vp)3991 vinactivef(struct vnode *vp)
3992 {
3993 int error;
3994
3995 ASSERT_VOP_ELOCKED(vp, "vinactive");
3996 ASSERT_VI_LOCKED(vp, "vinactive");
3997 VNPASS((vp->v_iflag & VI_DOINGINACT) == 0, vp);
3998 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3999 vp->v_iflag |= VI_DOINGINACT;
4000 vp->v_iflag &= ~VI_OWEINACT;
4001 VI_UNLOCK(vp);
4002
4003 /*
4004 * Before moving off the active list, we must be sure that any
4005 * modified pages are converted into the vnode's dirty
4006 * buffers, since these will no longer be checked once the
4007 * vnode is on the inactive list.
4008 *
4009 * The write-out of the dirty pages is asynchronous. At the
4010 * point that VOP_INACTIVE() is called, there could still be
4011 * pending I/O and dirty pages in the object.
4012 */
4013 if ((vp->v_vflag & VV_NOSYNC) == 0)
4014 vnode_pager_clean_async(vp);
4015
4016 error = VOP_INACTIVE(vp);
4017 VI_LOCK(vp);
4018 VNPASS(vp->v_iflag & VI_DOINGINACT, vp);
4019 vp->v_iflag &= ~VI_DOINGINACT;
4020 return (error);
4021 }
4022
4023 int
vinactive(struct vnode * vp)4024 vinactive(struct vnode *vp)
4025 {
4026
4027 ASSERT_VOP_ELOCKED(vp, "vinactive");
4028 ASSERT_VI_LOCKED(vp, "vinactive");
4029 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4030
4031 if ((vp->v_iflag & VI_OWEINACT) == 0)
4032 return (0);
4033 if (vp->v_iflag & VI_DOINGINACT)
4034 return (0);
4035 if (vp->v_usecount > 0) {
4036 vp->v_iflag &= ~VI_OWEINACT;
4037 return (0);
4038 }
4039 return (vinactivef(vp));
4040 }
4041
4042 /*
4043 * Remove any vnodes in the vnode table belonging to mount point mp.
4044 *
4045 * If FORCECLOSE is not specified, there should not be any active ones,
4046 * return error if any are found (nb: this is a user error, not a
4047 * system error). If FORCECLOSE is specified, detach any active vnodes
4048 * that are found.
4049 *
4050 * If WRITECLOSE is set, only flush out regular file vnodes open for
4051 * writing.
4052 *
4053 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
4054 *
4055 * `rootrefs' specifies the base reference count for the root vnode
4056 * of this filesystem. The root vnode is considered busy if its
4057 * v_usecount exceeds this value. On a successful return, vflush(, td)
4058 * will call vrele() on the root vnode exactly rootrefs times.
4059 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
4060 * be zero.
4061 */
4062 #ifdef DIAGNOSTIC
4063 static int busyprt = 0; /* print out busy vnodes */
4064 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
4065 #endif
4066
4067 int
vflush(struct mount * mp,int rootrefs,int flags,struct thread * td)4068 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
4069 {
4070 struct vnode *vp, *mvp, *rootvp = NULL;
4071 struct vattr vattr;
4072 int busy = 0, error;
4073
4074 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
4075 rootrefs, flags);
4076 if (rootrefs > 0) {
4077 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
4078 ("vflush: bad args"));
4079 /*
4080 * Get the filesystem root vnode. We can vput() it
4081 * immediately, since with rootrefs > 0, it won't go away.
4082 */
4083 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
4084 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
4085 __func__, error);
4086 return (error);
4087 }
4088 vput(rootvp);
4089 }
4090 loop:
4091 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
4092 vholdl(vp);
4093 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
4094 if (error) {
4095 vdrop(vp);
4096 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4097 goto loop;
4098 }
4099 /*
4100 * Skip over a vnodes marked VV_SYSTEM.
4101 */
4102 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
4103 VOP_UNLOCK(vp);
4104 vdrop(vp);
4105 continue;
4106 }
4107 /*
4108 * If WRITECLOSE is set, flush out unlinked but still open
4109 * files (even if open only for reading) and regular file
4110 * vnodes open for writing.
4111 */
4112 if (flags & WRITECLOSE) {
4113 vnode_pager_clean_async(vp);
4114 do {
4115 error = VOP_FSYNC(vp, MNT_WAIT, td);
4116 } while (error == ERELOOKUP);
4117 if (error != 0) {
4118 VOP_UNLOCK(vp);
4119 vdrop(vp);
4120 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4121 return (error);
4122 }
4123 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4124 VI_LOCK(vp);
4125
4126 if ((vp->v_type == VNON ||
4127 (error == 0 && vattr.va_nlink > 0)) &&
4128 (vp->v_writecount <= 0 || vp->v_type != VREG)) {
4129 VOP_UNLOCK(vp);
4130 vdropl(vp);
4131 continue;
4132 }
4133 } else
4134 VI_LOCK(vp);
4135 /*
4136 * With v_usecount == 0, all we need to do is clear out the
4137 * vnode data structures and we are done.
4138 *
4139 * If FORCECLOSE is set, forcibly close the vnode.
4140 */
4141 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
4142 vgonel(vp);
4143 } else {
4144 busy++;
4145 #ifdef DIAGNOSTIC
4146 if (busyprt)
4147 vn_printf(vp, "vflush: busy vnode ");
4148 #endif
4149 }
4150 VOP_UNLOCK(vp);
4151 vdropl(vp);
4152 }
4153 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
4154 /*
4155 * If just the root vnode is busy, and if its refcount
4156 * is equal to `rootrefs', then go ahead and kill it.
4157 */
4158 VI_LOCK(rootvp);
4159 KASSERT(busy > 0, ("vflush: not busy"));
4160 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
4161 ("vflush: usecount %d < rootrefs %d",
4162 rootvp->v_usecount, rootrefs));
4163 if (busy == 1 && rootvp->v_usecount == rootrefs) {
4164 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
4165 vgone(rootvp);
4166 VOP_UNLOCK(rootvp);
4167 busy = 0;
4168 } else
4169 VI_UNLOCK(rootvp);
4170 }
4171 if (busy) {
4172 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
4173 busy);
4174 return (EBUSY);
4175 }
4176 for (; rootrefs > 0; rootrefs--)
4177 vrele(rootvp);
4178 return (0);
4179 }
4180
4181 /*
4182 * Recycle an unused vnode.
4183 */
4184 int
vrecycle(struct vnode * vp)4185 vrecycle(struct vnode *vp)
4186 {
4187 int recycled;
4188
4189 VI_LOCK(vp);
4190 recycled = vrecyclel(vp);
4191 VI_UNLOCK(vp);
4192 return (recycled);
4193 }
4194
4195 /*
4196 * vrecycle, with the vp interlock held.
4197 */
4198 int
vrecyclel(struct vnode * vp)4199 vrecyclel(struct vnode *vp)
4200 {
4201 int recycled;
4202
4203 ASSERT_VOP_ELOCKED(vp, __func__);
4204 ASSERT_VI_LOCKED(vp, __func__);
4205 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4206 recycled = 0;
4207 if (vp->v_usecount == 0) {
4208 recycled = 1;
4209 vgonel(vp);
4210 }
4211 return (recycled);
4212 }
4213
4214 /*
4215 * Eliminate all activity associated with a vnode
4216 * in preparation for reuse.
4217 */
4218 void
vgone(struct vnode * vp)4219 vgone(struct vnode *vp)
4220 {
4221 VI_LOCK(vp);
4222 vgonel(vp);
4223 VI_UNLOCK(vp);
4224 }
4225
4226 /*
4227 * Notify upper mounts about reclaimed or unlinked vnode.
4228 */
4229 void
vfs_notify_upper(struct vnode * vp,enum vfs_notify_upper_type event)4230 vfs_notify_upper(struct vnode *vp, enum vfs_notify_upper_type event)
4231 {
4232 struct mount *mp;
4233 struct mount_upper_node *ump;
4234
4235 mp = atomic_load_ptr(&vp->v_mount);
4236 if (mp == NULL)
4237 return;
4238 if (TAILQ_EMPTY(&mp->mnt_notify))
4239 return;
4240
4241 MNT_ILOCK(mp);
4242 mp->mnt_upper_pending++;
4243 KASSERT(mp->mnt_upper_pending > 0,
4244 ("%s: mnt_upper_pending %d", __func__, mp->mnt_upper_pending));
4245 TAILQ_FOREACH(ump, &mp->mnt_notify, mnt_upper_link) {
4246 MNT_IUNLOCK(mp);
4247 switch (event) {
4248 case VFS_NOTIFY_UPPER_RECLAIM:
4249 VFS_RECLAIM_LOWERVP(ump->mp, vp);
4250 break;
4251 case VFS_NOTIFY_UPPER_UNLINK:
4252 VFS_UNLINK_LOWERVP(ump->mp, vp);
4253 break;
4254 }
4255 MNT_ILOCK(mp);
4256 }
4257 mp->mnt_upper_pending--;
4258 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 &&
4259 mp->mnt_upper_pending == 0) {
4260 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER;
4261 wakeup(&mp->mnt_uppers);
4262 }
4263 MNT_IUNLOCK(mp);
4264 }
4265
4266 /*
4267 * vgone, with the vp interlock held.
4268 */
4269 static void
vgonel(struct vnode * vp)4270 vgonel(struct vnode *vp)
4271 {
4272 struct thread *td;
4273 struct mount *mp;
4274 vm_object_t object;
4275 bool active, doinginact, oweinact;
4276
4277 ASSERT_VOP_ELOCKED(vp, "vgonel");
4278 ASSERT_VI_LOCKED(vp, "vgonel");
4279 VNASSERT(vp->v_holdcnt, vp,
4280 ("vgonel: vp %p has no reference.", vp));
4281 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4282 td = curthread;
4283
4284 /*
4285 * Don't vgonel if we're already doomed.
4286 */
4287 if (VN_IS_DOOMED(vp)) {
4288 VNPASS(vn_get_state(vp) == VSTATE_DESTROYING || \
4289 vn_get_state(vp) == VSTATE_DEAD, vp);
4290 return;
4291 }
4292 /*
4293 * Paired with freevnode.
4294 */
4295 vn_seqc_write_begin_locked(vp);
4296 vunlazy_gone(vp);
4297 vn_irflag_set_locked(vp, VIRF_DOOMED);
4298 vn_set_state(vp, VSTATE_DESTROYING);
4299
4300 /*
4301 * Check to see if the vnode is in use. If so, we have to
4302 * call VOP_CLOSE() and VOP_INACTIVE().
4303 *
4304 * It could be that VOP_INACTIVE() requested reclamation, in
4305 * which case we should avoid recursion, so check
4306 * VI_DOINGINACT. This is not precise but good enough.
4307 */
4308 active = vp->v_usecount > 0;
4309 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4310 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0;
4311
4312 /*
4313 * If we need to do inactive VI_OWEINACT will be set.
4314 */
4315 if (vp->v_iflag & VI_DEFINACT) {
4316 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count"));
4317 vp->v_iflag &= ~VI_DEFINACT;
4318 vdropl(vp);
4319 } else {
4320 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count"));
4321 VI_UNLOCK(vp);
4322 }
4323 cache_purge_vgone(vp);
4324 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
4325
4326 /*
4327 * If purging an active vnode, it must be closed and
4328 * deactivated before being reclaimed.
4329 */
4330 if (active)
4331 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
4332 if (!doinginact) {
4333 do {
4334 if (oweinact || active) {
4335 VI_LOCK(vp);
4336 vinactivef(vp);
4337 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4338 VI_UNLOCK(vp);
4339 }
4340 } while (oweinact);
4341 }
4342 if (vp->v_type == VSOCK)
4343 vfs_unp_reclaim(vp);
4344
4345 /*
4346 * Clean out any buffers associated with the vnode.
4347 * If the flush fails, just toss the buffers.
4348 */
4349 mp = NULL;
4350 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
4351 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
4352 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
4353 while (vinvalbuf(vp, 0, 0, 0) != 0)
4354 ;
4355 }
4356
4357 BO_LOCK(&vp->v_bufobj);
4358 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
4359 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
4360 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
4361 vp->v_bufobj.bo_clean.bv_cnt == 0,
4362 ("vp %p bufobj not invalidated", vp));
4363
4364 /*
4365 * For VMIO bufobj, BO_DEAD is set later, or in
4366 * vm_object_terminate() after the object's page queue is
4367 * flushed.
4368 */
4369 object = vp->v_bufobj.bo_object;
4370 if (object == NULL)
4371 vp->v_bufobj.bo_flag |= BO_DEAD;
4372 BO_UNLOCK(&vp->v_bufobj);
4373
4374 /*
4375 * Handle the VM part. Tmpfs handles v_object on its own (the
4376 * OBJT_VNODE check). Nullfs or other bypassing filesystems
4377 * should not touch the object borrowed from the lower vnode
4378 * (the handle check).
4379 */
4380 if (object != NULL && object->type == OBJT_VNODE &&
4381 object->handle == vp)
4382 vnode_destroy_vobject(vp);
4383
4384 /*
4385 * Reclaim the vnode.
4386 */
4387 if (VOP_RECLAIM(vp))
4388 panic("vgone: cannot reclaim");
4389 if (mp != NULL)
4390 vn_finished_secondary_write(mp);
4391 VNASSERT(vp->v_object == NULL, vp,
4392 ("vop_reclaim left v_object vp=%p", vp));
4393 /*
4394 * Clear the advisory locks and wake up waiting threads.
4395 */
4396 if (vp->v_lockf != NULL) {
4397 (void)VOP_ADVLOCKPURGE(vp);
4398 vp->v_lockf = NULL;
4399 }
4400 /*
4401 * Delete from old mount point vnode list.
4402 */
4403 if (vp->v_mount == NULL) {
4404 VI_LOCK(vp);
4405 } else {
4406 delmntque(vp);
4407 ASSERT_VI_LOCKED(vp, "vgonel 2");
4408 }
4409 /*
4410 * Done with purge, reset to the standard lock and invalidate
4411 * the vnode.
4412 */
4413 vp->v_vnlock = &vp->v_lock;
4414 vp->v_op = &dead_vnodeops;
4415 vp->v_type = VBAD;
4416 vn_set_state(vp, VSTATE_DEAD);
4417 }
4418
4419 /*
4420 * Print out a description of a vnode.
4421 */
4422 static const char *const vtypename[] = {
4423 [VNON] = "VNON",
4424 [VREG] = "VREG",
4425 [VDIR] = "VDIR",
4426 [VBLK] = "VBLK",
4427 [VCHR] = "VCHR",
4428 [VLNK] = "VLNK",
4429 [VSOCK] = "VSOCK",
4430 [VFIFO] = "VFIFO",
4431 [VBAD] = "VBAD",
4432 [VMARKER] = "VMARKER",
4433 };
4434 _Static_assert(nitems(vtypename) == VLASTTYPE + 1,
4435 "vnode type name not added to vtypename");
4436
4437 static const char *const vstatename[] = {
4438 [VSTATE_UNINITIALIZED] = "VSTATE_UNINITIALIZED",
4439 [VSTATE_CONSTRUCTED] = "VSTATE_CONSTRUCTED",
4440 [VSTATE_DESTROYING] = "VSTATE_DESTROYING",
4441 [VSTATE_DEAD] = "VSTATE_DEAD",
4442 };
4443 _Static_assert(nitems(vstatename) == VLASTSTATE + 1,
4444 "vnode state name not added to vstatename");
4445
4446 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0,
4447 "new hold count flag not added to vn_printf");
4448
4449 void
vn_printf(struct vnode * vp,const char * fmt,...)4450 vn_printf(struct vnode *vp, const char *fmt, ...)
4451 {
4452 va_list ap;
4453 char buf[256], buf2[16];
4454 u_long flags;
4455 u_int holdcnt;
4456 short irflag;
4457
4458 va_start(ap, fmt);
4459 vprintf(fmt, ap);
4460 va_end(ap);
4461 printf("%p: ", (void *)vp);
4462 printf("type %s state %s op %p\n", vtypename[vp->v_type],
4463 vstatename[vp->v_state], vp->v_op);
4464 holdcnt = atomic_load_int(&vp->v_holdcnt);
4465 printf(" usecount %d, writecount %d, refcount %d seqc users %d",
4466 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS,
4467 vp->v_seqc_users);
4468 switch (vp->v_type) {
4469 case VDIR:
4470 printf(" mountedhere %p\n", vp->v_mountedhere);
4471 break;
4472 case VCHR:
4473 printf(" rdev %p\n", vp->v_rdev);
4474 break;
4475 case VSOCK:
4476 printf(" socket %p\n", vp->v_unpcb);
4477 break;
4478 case VFIFO:
4479 printf(" fifoinfo %p\n", vp->v_fifoinfo);
4480 break;
4481 default:
4482 printf("\n");
4483 break;
4484 }
4485 buf[0] = '\0';
4486 buf[1] = '\0';
4487 if (holdcnt & VHOLD_NO_SMR)
4488 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf));
4489 printf(" hold count flags (%s)\n", buf + 1);
4490
4491 buf[0] = '\0';
4492 buf[1] = '\0';
4493 irflag = vn_irflag_read(vp);
4494 if (irflag & VIRF_DOOMED)
4495 strlcat(buf, "|VIRF_DOOMED", sizeof(buf));
4496 if (irflag & VIRF_PGREAD)
4497 strlcat(buf, "|VIRF_PGREAD", sizeof(buf));
4498 if (irflag & VIRF_MOUNTPOINT)
4499 strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf));
4500 if (irflag & VIRF_TEXT_REF)
4501 strlcat(buf, "|VIRF_TEXT_REF", sizeof(buf));
4502 flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT | VIRF_TEXT_REF);
4503 if (flags != 0) {
4504 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags);
4505 strlcat(buf, buf2, sizeof(buf));
4506 }
4507 if (vp->v_vflag & VV_ROOT)
4508 strlcat(buf, "|VV_ROOT", sizeof(buf));
4509 if (vp->v_vflag & VV_ISTTY)
4510 strlcat(buf, "|VV_ISTTY", sizeof(buf));
4511 if (vp->v_vflag & VV_NOSYNC)
4512 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
4513 if (vp->v_vflag & VV_ETERNALDEV)
4514 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
4515 if (vp->v_vflag & VV_CACHEDLABEL)
4516 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
4517 if (vp->v_vflag & VV_VMSIZEVNLOCK)
4518 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf));
4519 if (vp->v_vflag & VV_COPYONWRITE)
4520 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
4521 if (vp->v_vflag & VV_SYSTEM)
4522 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
4523 if (vp->v_vflag & VV_PROCDEP)
4524 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
4525 if (vp->v_vflag & VV_DELETED)
4526 strlcat(buf, "|VV_DELETED", sizeof(buf));
4527 if (vp->v_vflag & VV_MD)
4528 strlcat(buf, "|VV_MD", sizeof(buf));
4529 if (vp->v_vflag & VV_FORCEINSMQ)
4530 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
4531 if (vp->v_vflag & VV_READLINK)
4532 strlcat(buf, "|VV_READLINK", sizeof(buf));
4533 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
4534 VV_CACHEDLABEL | VV_VMSIZEVNLOCK | VV_COPYONWRITE | VV_SYSTEM |
4535 VV_PROCDEP | VV_DELETED | VV_MD | VV_FORCEINSMQ | VV_READLINK);
4536 if (flags != 0) {
4537 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
4538 strlcat(buf, buf2, sizeof(buf));
4539 }
4540 if (vp->v_iflag & VI_MOUNT)
4541 strlcat(buf, "|VI_MOUNT", sizeof(buf));
4542 if (vp->v_iflag & VI_DOINGINACT)
4543 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
4544 if (vp->v_iflag & VI_OWEINACT)
4545 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
4546 if (vp->v_iflag & VI_DEFINACT)
4547 strlcat(buf, "|VI_DEFINACT", sizeof(buf));
4548 if (vp->v_iflag & VI_FOPENING)
4549 strlcat(buf, "|VI_FOPENING", sizeof(buf));
4550 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOINGINACT |
4551 VI_OWEINACT | VI_DEFINACT | VI_FOPENING);
4552 if (flags != 0) {
4553 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
4554 strlcat(buf, buf2, sizeof(buf));
4555 }
4556 if (vp->v_mflag & VMP_LAZYLIST)
4557 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf));
4558 flags = vp->v_mflag & ~(VMP_LAZYLIST);
4559 if (flags != 0) {
4560 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags);
4561 strlcat(buf, buf2, sizeof(buf));
4562 }
4563 printf(" flags (%s)", buf + 1);
4564 if (mtx_owned(VI_MTX(vp)))
4565 printf(" VI_LOCKed");
4566 printf("\n");
4567 if (vp->v_object != NULL)
4568 printf(" v_object %p ref %d pages %d "
4569 "cleanbuf %d dirtybuf %d\n",
4570 vp->v_object, vp->v_object->ref_count,
4571 vp->v_object->resident_page_count,
4572 vp->v_bufobj.bo_clean.bv_cnt,
4573 vp->v_bufobj.bo_dirty.bv_cnt);
4574 printf(" ");
4575 lockmgr_printinfo(vp->v_vnlock);
4576 if (vp->v_data != NULL)
4577 VOP_PRINT(vp);
4578 }
4579
4580 #ifdef DDB
4581 /*
4582 * List all of the locked vnodes in the system.
4583 * Called when debugging the kernel.
4584 */
DB_SHOW_COMMAND_FLAGS(lockedvnods,lockedvnodes,DB_CMD_MEMSAFE)4585 DB_SHOW_COMMAND_FLAGS(lockedvnods, lockedvnodes, DB_CMD_MEMSAFE)
4586 {
4587 struct mount *mp;
4588 struct vnode *vp;
4589
4590 /*
4591 * Note: because this is DDB, we can't obey the locking semantics
4592 * for these structures, which means we could catch an inconsistent
4593 * state and dereference a nasty pointer. Not much to be done
4594 * about that.
4595 */
4596 db_printf("Locked vnodes\n");
4597 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4598 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4599 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
4600 vn_printf(vp, "vnode ");
4601 }
4602 }
4603 }
4604
4605 /*
4606 * Show details about the given vnode.
4607 */
DB_SHOW_COMMAND(vnode,db_show_vnode)4608 DB_SHOW_COMMAND(vnode, db_show_vnode)
4609 {
4610 struct vnode *vp;
4611
4612 if (!have_addr)
4613 return;
4614 vp = (struct vnode *)addr;
4615 vn_printf(vp, "vnode ");
4616 }
4617
4618 /*
4619 * Show details about the given mount point.
4620 */
DB_SHOW_COMMAND(mount,db_show_mount)4621 DB_SHOW_COMMAND(mount, db_show_mount)
4622 {
4623 struct mount *mp;
4624 struct vfsopt *opt;
4625 struct statfs *sp;
4626 struct vnode *vp;
4627 char buf[512];
4628 uint64_t mflags;
4629 u_int flags;
4630
4631 if (!have_addr) {
4632 /* No address given, print short info about all mount points. */
4633 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4634 db_printf("%p %s on %s (%s)\n", mp,
4635 mp->mnt_stat.f_mntfromname,
4636 mp->mnt_stat.f_mntonname,
4637 mp->mnt_stat.f_fstypename);
4638 if (db_pager_quit)
4639 break;
4640 }
4641 db_printf("\nMore info: show mount <addr>\n");
4642 return;
4643 }
4644
4645 mp = (struct mount *)addr;
4646 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
4647 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
4648
4649 buf[0] = '\0';
4650 mflags = mp->mnt_flag;
4651 #define MNT_FLAG(flag) do { \
4652 if (mflags & (flag)) { \
4653 if (buf[0] != '\0') \
4654 strlcat(buf, ", ", sizeof(buf)); \
4655 strlcat(buf, (#flag) + 4, sizeof(buf)); \
4656 mflags &= ~(flag); \
4657 } \
4658 } while (0)
4659 MNT_FLAG(MNT_RDONLY);
4660 MNT_FLAG(MNT_SYNCHRONOUS);
4661 MNT_FLAG(MNT_NOEXEC);
4662 MNT_FLAG(MNT_NOSUID);
4663 MNT_FLAG(MNT_NFS4ACLS);
4664 MNT_FLAG(MNT_UNION);
4665 MNT_FLAG(MNT_ASYNC);
4666 MNT_FLAG(MNT_SUIDDIR);
4667 MNT_FLAG(MNT_SOFTDEP);
4668 MNT_FLAG(MNT_NOSYMFOLLOW);
4669 MNT_FLAG(MNT_GJOURNAL);
4670 MNT_FLAG(MNT_MULTILABEL);
4671 MNT_FLAG(MNT_ACLS);
4672 MNT_FLAG(MNT_NOATIME);
4673 MNT_FLAG(MNT_NOCLUSTERR);
4674 MNT_FLAG(MNT_NOCLUSTERW);
4675 MNT_FLAG(MNT_SUJ);
4676 MNT_FLAG(MNT_EXRDONLY);
4677 MNT_FLAG(MNT_EXPORTED);
4678 MNT_FLAG(MNT_DEFEXPORTED);
4679 MNT_FLAG(MNT_EXPORTANON);
4680 MNT_FLAG(MNT_EXKERB);
4681 MNT_FLAG(MNT_EXPUBLIC);
4682 MNT_FLAG(MNT_LOCAL);
4683 MNT_FLAG(MNT_QUOTA);
4684 MNT_FLAG(MNT_ROOTFS);
4685 MNT_FLAG(MNT_USER);
4686 MNT_FLAG(MNT_IGNORE);
4687 MNT_FLAG(MNT_UPDATE);
4688 MNT_FLAG(MNT_DELEXPORT);
4689 MNT_FLAG(MNT_RELOAD);
4690 MNT_FLAG(MNT_FORCE);
4691 MNT_FLAG(MNT_SNAPSHOT);
4692 MNT_FLAG(MNT_BYFSID);
4693 #undef MNT_FLAG
4694 if (mflags != 0) {
4695 if (buf[0] != '\0')
4696 strlcat(buf, ", ", sizeof(buf));
4697 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4698 "0x%016jx", mflags);
4699 }
4700 db_printf(" mnt_flag = %s\n", buf);
4701
4702 buf[0] = '\0';
4703 flags = mp->mnt_kern_flag;
4704 #define MNT_KERN_FLAG(flag) do { \
4705 if (flags & (flag)) { \
4706 if (buf[0] != '\0') \
4707 strlcat(buf, ", ", sizeof(buf)); \
4708 strlcat(buf, (#flag) + 5, sizeof(buf)); \
4709 flags &= ~(flag); \
4710 } \
4711 } while (0)
4712 MNT_KERN_FLAG(MNTK_UNMOUNTF);
4713 MNT_KERN_FLAG(MNTK_ASYNC);
4714 MNT_KERN_FLAG(MNTK_SOFTDEP);
4715 MNT_KERN_FLAG(MNTK_NOMSYNC);
4716 MNT_KERN_FLAG(MNTK_DRAINING);
4717 MNT_KERN_FLAG(MNTK_REFEXPIRE);
4718 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
4719 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
4720 MNT_KERN_FLAG(MNTK_NO_IOPF);
4721 MNT_KERN_FLAG(MNTK_RECURSE);
4722 MNT_KERN_FLAG(MNTK_UPPER_WAITER);
4723 MNT_KERN_FLAG(MNTK_UNLOCKED_INSMNTQUE);
4724 MNT_KERN_FLAG(MNTK_USES_BCACHE);
4725 MNT_KERN_FLAG(MNTK_VMSETSIZE_BUG);
4726 MNT_KERN_FLAG(MNTK_FPLOOKUP);
4727 MNT_KERN_FLAG(MNTK_TASKQUEUE_WAITER);
4728 MNT_KERN_FLAG(MNTK_NOASYNC);
4729 MNT_KERN_FLAG(MNTK_UNMOUNT);
4730 MNT_KERN_FLAG(MNTK_MWAIT);
4731 MNT_KERN_FLAG(MNTK_SUSPEND);
4732 MNT_KERN_FLAG(MNTK_SUSPEND2);
4733 MNT_KERN_FLAG(MNTK_SUSPENDED);
4734 MNT_KERN_FLAG(MNTK_NULL_NOCACHE);
4735 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
4736 #undef MNT_KERN_FLAG
4737 if (flags != 0) {
4738 if (buf[0] != '\0')
4739 strlcat(buf, ", ", sizeof(buf));
4740 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4741 "0x%08x", flags);
4742 }
4743 db_printf(" mnt_kern_flag = %s\n", buf);
4744
4745 db_printf(" mnt_opt = ");
4746 opt = TAILQ_FIRST(mp->mnt_opt);
4747 if (opt != NULL) {
4748 db_printf("%s", opt->name);
4749 opt = TAILQ_NEXT(opt, link);
4750 while (opt != NULL) {
4751 db_printf(", %s", opt->name);
4752 opt = TAILQ_NEXT(opt, link);
4753 }
4754 }
4755 db_printf("\n");
4756
4757 sp = &mp->mnt_stat;
4758 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
4759 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
4760 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
4761 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
4762 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
4763 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
4764 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
4765 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
4766 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
4767 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
4768 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
4769 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
4770
4771 db_printf(" mnt_cred = { uid=%u ruid=%u",
4772 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
4773 if (jailed(mp->mnt_cred))
4774 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
4775 db_printf(" }\n");
4776 db_printf(" mnt_ref = %d (with %d in the struct)\n",
4777 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref);
4778 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
4779 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
4780 db_printf(" mnt_lazyvnodelistsize = %d\n",
4781 mp->mnt_lazyvnodelistsize);
4782 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n",
4783 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount);
4784 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
4785 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
4786 db_printf(" mnt_lockref = %d (with %d in the struct)\n",
4787 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref);
4788 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
4789 db_printf(" mnt_secondary_accwrites = %d\n",
4790 mp->mnt_secondary_accwrites);
4791 db_printf(" mnt_gjprovider = %s\n",
4792 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
4793 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops);
4794
4795 db_printf("\n\nList of active vnodes\n");
4796 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4797 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) {
4798 vn_printf(vp, "vnode ");
4799 if (db_pager_quit)
4800 break;
4801 }
4802 }
4803 db_printf("\n\nList of inactive vnodes\n");
4804 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4805 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) {
4806 vn_printf(vp, "vnode ");
4807 if (db_pager_quit)
4808 break;
4809 }
4810 }
4811 }
4812 #endif /* DDB */
4813
4814 /*
4815 * Fill in a struct xvfsconf based on a struct vfsconf.
4816 */
4817 static int
vfsconf2x(struct sysctl_req * req,struct vfsconf * vfsp)4818 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
4819 {
4820 struct xvfsconf xvfsp;
4821
4822 bzero(&xvfsp, sizeof(xvfsp));
4823 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4824 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4825 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4826 xvfsp.vfc_flags = vfsp->vfc_flags;
4827 /*
4828 * These are unused in userland, we keep them
4829 * to not break binary compatibility.
4830 */
4831 xvfsp.vfc_vfsops = NULL;
4832 xvfsp.vfc_next = NULL;
4833 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4834 }
4835
4836 #ifdef COMPAT_FREEBSD32
4837 struct xvfsconf32 {
4838 uint32_t vfc_vfsops;
4839 char vfc_name[MFSNAMELEN];
4840 int32_t vfc_typenum;
4841 int32_t vfc_refcount;
4842 int32_t vfc_flags;
4843 uint32_t vfc_next;
4844 };
4845
4846 static int
vfsconf2x32(struct sysctl_req * req,struct vfsconf * vfsp)4847 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
4848 {
4849 struct xvfsconf32 xvfsp;
4850
4851 bzero(&xvfsp, sizeof(xvfsp));
4852 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4853 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4854 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4855 xvfsp.vfc_flags = vfsp->vfc_flags;
4856 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4857 }
4858 #endif
4859
4860 /*
4861 * Top level filesystem related information gathering.
4862 */
4863 static int
sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)4864 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
4865 {
4866 struct vfsconf *vfsp;
4867 int error;
4868
4869 error = 0;
4870 vfsconf_slock();
4871 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4872 #ifdef COMPAT_FREEBSD32
4873 if (req->flags & SCTL_MASK32)
4874 error = vfsconf2x32(req, vfsp);
4875 else
4876 #endif
4877 error = vfsconf2x(req, vfsp);
4878 if (error)
4879 break;
4880 }
4881 vfsconf_sunlock();
4882 return (error);
4883 }
4884
4885 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
4886 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
4887 "S,xvfsconf", "List of all configured filesystems");
4888
4889 #ifndef BURN_BRIDGES
4890 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
4891
4892 static int
vfs_sysctl(SYSCTL_HANDLER_ARGS)4893 vfs_sysctl(SYSCTL_HANDLER_ARGS)
4894 {
4895 int *name = (int *)arg1 - 1; /* XXX */
4896 u_int namelen = arg2 + 1; /* XXX */
4897 struct vfsconf *vfsp;
4898
4899 log(LOG_WARNING, "userland calling deprecated sysctl, "
4900 "please rebuild world\n");
4901
4902 #if 1 || defined(COMPAT_PRELITE2)
4903 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
4904 if (namelen == 1)
4905 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
4906 #endif
4907
4908 switch (name[1]) {
4909 case VFS_MAXTYPENUM:
4910 if (namelen != 2)
4911 return (ENOTDIR);
4912 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
4913 case VFS_CONF:
4914 if (namelen != 3)
4915 return (ENOTDIR); /* overloaded */
4916 vfsconf_slock();
4917 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4918 if (vfsp->vfc_typenum == name[2])
4919 break;
4920 }
4921 vfsconf_sunlock();
4922 if (vfsp == NULL)
4923 return (EOPNOTSUPP);
4924 #ifdef COMPAT_FREEBSD32
4925 if (req->flags & SCTL_MASK32)
4926 return (vfsconf2x32(req, vfsp));
4927 else
4928 #endif
4929 return (vfsconf2x(req, vfsp));
4930 }
4931 return (EOPNOTSUPP);
4932 }
4933
4934 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
4935 CTLFLAG_MPSAFE, vfs_sysctl,
4936 "Generic filesystem");
4937
4938 #if 1 || defined(COMPAT_PRELITE2)
4939
4940 static int
sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)4941 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
4942 {
4943 int error;
4944 struct vfsconf *vfsp;
4945 struct ovfsconf ovfs;
4946
4947 vfsconf_slock();
4948 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4949 bzero(&ovfs, sizeof(ovfs));
4950 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
4951 strcpy(ovfs.vfc_name, vfsp->vfc_name);
4952 ovfs.vfc_index = vfsp->vfc_typenum;
4953 ovfs.vfc_refcount = vfsp->vfc_refcount;
4954 ovfs.vfc_flags = vfsp->vfc_flags;
4955 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
4956 if (error != 0) {
4957 vfsconf_sunlock();
4958 return (error);
4959 }
4960 }
4961 vfsconf_sunlock();
4962 return (0);
4963 }
4964
4965 #endif /* 1 || COMPAT_PRELITE2 */
4966 #endif /* !BURN_BRIDGES */
4967
4968 static void
unmount_or_warn(struct mount * mp)4969 unmount_or_warn(struct mount *mp)
4970 {
4971 int error;
4972
4973 error = dounmount(mp, MNT_FORCE, curthread);
4974 if (error != 0) {
4975 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
4976 if (error == EBUSY)
4977 printf("BUSY)\n");
4978 else
4979 printf("%d)\n", error);
4980 }
4981 }
4982
4983 /*
4984 * Unmount all filesystems. The list is traversed in reverse order
4985 * of mounting to avoid dependencies.
4986 */
4987 void
vfs_unmountall(void)4988 vfs_unmountall(void)
4989 {
4990 struct mount *mp, *tmp;
4991
4992 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
4993
4994 /*
4995 * Since this only runs when rebooting, it is not interlocked.
4996 */
4997 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
4998 vfs_ref(mp);
4999
5000 /*
5001 * Forcibly unmounting "/dev" before "/" would prevent clean
5002 * unmount of the latter.
5003 */
5004 if (mp == rootdevmp)
5005 continue;
5006
5007 unmount_or_warn(mp);
5008 }
5009
5010 if (rootdevmp != NULL)
5011 unmount_or_warn(rootdevmp);
5012 }
5013
5014 static void
vfs_deferred_inactive(struct vnode * vp,int lkflags)5015 vfs_deferred_inactive(struct vnode *vp, int lkflags)
5016 {
5017
5018 ASSERT_VI_LOCKED(vp, __func__);
5019 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
5020 if ((vp->v_iflag & VI_OWEINACT) == 0) {
5021 vdropl(vp);
5022 return;
5023 }
5024 if (vn_lock(vp, lkflags) == 0) {
5025 VI_LOCK(vp);
5026 vinactive(vp);
5027 VOP_UNLOCK(vp);
5028 vdropl(vp);
5029 return;
5030 }
5031 vdefer_inactive_unlocked(vp);
5032 }
5033
5034 static int
vfs_periodic_inactive_filter(struct vnode * vp,void * arg)5035 vfs_periodic_inactive_filter(struct vnode *vp, void *arg)
5036 {
5037
5038 return (vp->v_iflag & VI_DEFINACT);
5039 }
5040
5041 static void __noinline
vfs_periodic_inactive(struct mount * mp,int flags)5042 vfs_periodic_inactive(struct mount *mp, int flags)
5043 {
5044 struct vnode *vp, *mvp;
5045 int lkflags;
5046
5047 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5048 if (flags != MNT_WAIT)
5049 lkflags |= LK_NOWAIT;
5050
5051 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) {
5052 if ((vp->v_iflag & VI_DEFINACT) == 0) {
5053 VI_UNLOCK(vp);
5054 continue;
5055 }
5056 vp->v_iflag &= ~VI_DEFINACT;
5057 vfs_deferred_inactive(vp, lkflags);
5058 }
5059 }
5060
5061 static inline bool
vfs_want_msync(struct vnode * vp)5062 vfs_want_msync(struct vnode *vp)
5063 {
5064 struct vm_object *obj;
5065
5066 /*
5067 * This test may be performed without any locks held.
5068 * We rely on vm_object's type stability.
5069 */
5070 if (vp->v_vflag & VV_NOSYNC)
5071 return (false);
5072 obj = vp->v_object;
5073 return (obj != NULL && vm_object_mightbedirty(obj));
5074 }
5075
5076 static int
vfs_periodic_msync_inactive_filter(struct vnode * vp,void * arg __unused)5077 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused)
5078 {
5079
5080 if (vp->v_vflag & VV_NOSYNC)
5081 return (false);
5082 if (vp->v_iflag & VI_DEFINACT)
5083 return (true);
5084 return (vfs_want_msync(vp));
5085 }
5086
5087 static void __noinline
vfs_periodic_msync_inactive(struct mount * mp,int flags)5088 vfs_periodic_msync_inactive(struct mount *mp, int flags)
5089 {
5090 struct vnode *vp, *mvp;
5091 int lkflags;
5092 bool seen_defer;
5093
5094 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5095 if (flags != MNT_WAIT)
5096 lkflags |= LK_NOWAIT;
5097
5098 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) {
5099 seen_defer = false;
5100 if (vp->v_iflag & VI_DEFINACT) {
5101 vp->v_iflag &= ~VI_DEFINACT;
5102 seen_defer = true;
5103 }
5104 if (!vfs_want_msync(vp)) {
5105 if (seen_defer)
5106 vfs_deferred_inactive(vp, lkflags);
5107 else
5108 VI_UNLOCK(vp);
5109 continue;
5110 }
5111 if (vget(vp, lkflags) == 0) {
5112 if ((vp->v_vflag & VV_NOSYNC) == 0) {
5113 if (flags == MNT_WAIT)
5114 vnode_pager_clean_sync(vp);
5115 else
5116 vnode_pager_clean_async(vp);
5117 }
5118 vput(vp);
5119 if (seen_defer)
5120 vdrop(vp);
5121 } else {
5122 if (seen_defer)
5123 vdefer_inactive_unlocked(vp);
5124 }
5125 }
5126 }
5127
5128 void
vfs_periodic(struct mount * mp,int flags)5129 vfs_periodic(struct mount *mp, int flags)
5130 {
5131
5132 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
5133
5134 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0)
5135 vfs_periodic_inactive(mp, flags);
5136 else
5137 vfs_periodic_msync_inactive(mp, flags);
5138 }
5139
5140 static void
destroy_vpollinfo_free(struct vpollinfo * vi)5141 destroy_vpollinfo_free(struct vpollinfo *vi)
5142 {
5143
5144 knlist_destroy(&vi->vpi_selinfo.si_note);
5145 mtx_destroy(&vi->vpi_lock);
5146 free(vi, M_VNODEPOLL);
5147 }
5148
5149 static void
destroy_vpollinfo(struct vpollinfo * vi)5150 destroy_vpollinfo(struct vpollinfo *vi)
5151 {
5152
5153 knlist_clear(&vi->vpi_selinfo.si_note, 1);
5154 seldrain(&vi->vpi_selinfo);
5155 destroy_vpollinfo_free(vi);
5156 }
5157
5158 /*
5159 * Initialize per-vnode helper structure to hold poll-related state.
5160 */
5161 void
v_addpollinfo(struct vnode * vp)5162 v_addpollinfo(struct vnode *vp)
5163 {
5164 struct vpollinfo *vi;
5165
5166 if (vp->v_pollinfo != NULL)
5167 return;
5168 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO);
5169 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
5170 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
5171 vfs_knlunlock, vfs_knl_assert_lock);
5172 VI_LOCK(vp);
5173 if (vp->v_pollinfo != NULL) {
5174 VI_UNLOCK(vp);
5175 destroy_vpollinfo_free(vi);
5176 return;
5177 }
5178 vp->v_pollinfo = vi;
5179 VI_UNLOCK(vp);
5180 }
5181
5182 /*
5183 * Record a process's interest in events which might happen to
5184 * a vnode. Because poll uses the historic select-style interface
5185 * internally, this routine serves as both the ``check for any
5186 * pending events'' and the ``record my interest in future events''
5187 * functions. (These are done together, while the lock is held,
5188 * to avoid race conditions.)
5189 */
5190 int
vn_pollrecord(struct vnode * vp,struct thread * td,int events)5191 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
5192 {
5193
5194 v_addpollinfo(vp);
5195 mtx_lock(&vp->v_pollinfo->vpi_lock);
5196 if (vp->v_pollinfo->vpi_revents & events) {
5197 /*
5198 * This leaves events we are not interested
5199 * in available for the other process which
5200 * which presumably had requested them
5201 * (otherwise they would never have been
5202 * recorded).
5203 */
5204 events &= vp->v_pollinfo->vpi_revents;
5205 vp->v_pollinfo->vpi_revents &= ~events;
5206
5207 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5208 return (events);
5209 }
5210 vp->v_pollinfo->vpi_events |= events;
5211 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
5212 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5213 return (0);
5214 }
5215
5216 /*
5217 * Routine to create and manage a filesystem syncer vnode.
5218 */
5219 #define sync_close ((int (*)(struct vop_close_args *))nullop)
5220 static int sync_fsync(struct vop_fsync_args *);
5221 static int sync_inactive(struct vop_inactive_args *);
5222 static int sync_reclaim(struct vop_reclaim_args *);
5223
5224 static struct vop_vector sync_vnodeops = {
5225 .vop_bypass = VOP_EOPNOTSUPP,
5226 .vop_close = sync_close,
5227 .vop_fsync = sync_fsync,
5228 .vop_getwritemount = vop_stdgetwritemount,
5229 .vop_inactive = sync_inactive,
5230 .vop_need_inactive = vop_stdneed_inactive,
5231 .vop_reclaim = sync_reclaim,
5232 .vop_lock1 = vop_stdlock,
5233 .vop_unlock = vop_stdunlock,
5234 .vop_islocked = vop_stdislocked,
5235 .vop_fplookup_vexec = VOP_EAGAIN,
5236 .vop_fplookup_symlink = VOP_EAGAIN,
5237 };
5238 VFS_VOP_VECTOR_REGISTER(sync_vnodeops);
5239
5240 /*
5241 * Create a new filesystem syncer vnode for the specified mount point.
5242 */
5243 void
vfs_allocate_syncvnode(struct mount * mp)5244 vfs_allocate_syncvnode(struct mount *mp)
5245 {
5246 struct vnode *vp;
5247 struct bufobj *bo;
5248 static long start, incr, next;
5249 int error;
5250
5251 /* Allocate a new vnode */
5252 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
5253 if (error != 0)
5254 panic("vfs_allocate_syncvnode: getnewvnode() failed");
5255 vp->v_type = VNON;
5256 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5257 vp->v_vflag |= VV_FORCEINSMQ;
5258 error = insmntque1(vp, mp);
5259 if (error != 0)
5260 panic("vfs_allocate_syncvnode: insmntque() failed");
5261 vp->v_vflag &= ~VV_FORCEINSMQ;
5262 vn_set_state(vp, VSTATE_CONSTRUCTED);
5263 VOP_UNLOCK(vp);
5264 /*
5265 * Place the vnode onto the syncer worklist. We attempt to
5266 * scatter them about on the list so that they will go off
5267 * at evenly distributed times even if all the filesystems
5268 * are mounted at once.
5269 */
5270 next += incr;
5271 if (next == 0 || next > syncer_maxdelay) {
5272 start /= 2;
5273 incr /= 2;
5274 if (start == 0) {
5275 start = syncer_maxdelay / 2;
5276 incr = syncer_maxdelay;
5277 }
5278 next = start;
5279 }
5280 bo = &vp->v_bufobj;
5281 BO_LOCK(bo);
5282 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
5283 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
5284 mtx_lock(&sync_mtx);
5285 sync_vnode_count++;
5286 if (mp->mnt_syncer == NULL) {
5287 mp->mnt_syncer = vp;
5288 vp = NULL;
5289 }
5290 mtx_unlock(&sync_mtx);
5291 BO_UNLOCK(bo);
5292 if (vp != NULL) {
5293 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5294 vgone(vp);
5295 vput(vp);
5296 }
5297 }
5298
5299 void
vfs_deallocate_syncvnode(struct mount * mp)5300 vfs_deallocate_syncvnode(struct mount *mp)
5301 {
5302 struct vnode *vp;
5303
5304 mtx_lock(&sync_mtx);
5305 vp = mp->mnt_syncer;
5306 if (vp != NULL)
5307 mp->mnt_syncer = NULL;
5308 mtx_unlock(&sync_mtx);
5309 if (vp != NULL)
5310 vrele(vp);
5311 }
5312
5313 /*
5314 * Do a lazy sync of the filesystem.
5315 */
5316 static int
sync_fsync(struct vop_fsync_args * ap)5317 sync_fsync(struct vop_fsync_args *ap)
5318 {
5319 struct vnode *syncvp = ap->a_vp;
5320 struct mount *mp = syncvp->v_mount;
5321 int error, save;
5322 struct bufobj *bo;
5323
5324 /*
5325 * We only need to do something if this is a lazy evaluation.
5326 */
5327 if (ap->a_waitfor != MNT_LAZY)
5328 return (0);
5329
5330 /*
5331 * Move ourselves to the back of the sync list.
5332 */
5333 bo = &syncvp->v_bufobj;
5334 BO_LOCK(bo);
5335 vn_syncer_add_to_worklist(bo, syncdelay);
5336 BO_UNLOCK(bo);
5337
5338 /*
5339 * Walk the list of vnodes pushing all that are dirty and
5340 * not already on the sync list.
5341 */
5342 if (vfs_busy(mp, MBF_NOWAIT) != 0)
5343 return (0);
5344 VOP_UNLOCK(syncvp);
5345 save = curthread_pflags_set(TDP_SYNCIO);
5346 /*
5347 * The filesystem at hand may be idle with free vnodes stored in the
5348 * batch. Return them instead of letting them stay there indefinitely.
5349 */
5350 vfs_periodic(mp, MNT_NOWAIT);
5351 error = VFS_SYNC(mp, MNT_LAZY);
5352 curthread_pflags_restore(save);
5353 vn_lock(syncvp, LK_EXCLUSIVE | LK_RETRY);
5354 vfs_unbusy(mp);
5355 return (error);
5356 }
5357
5358 /*
5359 * The syncer vnode is no referenced.
5360 */
5361 static int
sync_inactive(struct vop_inactive_args * ap)5362 sync_inactive(struct vop_inactive_args *ap)
5363 {
5364
5365 vgone(ap->a_vp);
5366 return (0);
5367 }
5368
5369 /*
5370 * The syncer vnode is no longer needed and is being decommissioned.
5371 *
5372 * Modifications to the worklist must be protected by sync_mtx.
5373 */
5374 static int
sync_reclaim(struct vop_reclaim_args * ap)5375 sync_reclaim(struct vop_reclaim_args *ap)
5376 {
5377 struct vnode *vp = ap->a_vp;
5378 struct bufobj *bo;
5379
5380 bo = &vp->v_bufobj;
5381 BO_LOCK(bo);
5382 mtx_lock(&sync_mtx);
5383 if (vp->v_mount->mnt_syncer == vp)
5384 vp->v_mount->mnt_syncer = NULL;
5385 if (bo->bo_flag & BO_ONWORKLST) {
5386 LIST_REMOVE(bo, bo_synclist);
5387 syncer_worklist_len--;
5388 sync_vnode_count--;
5389 bo->bo_flag &= ~BO_ONWORKLST;
5390 }
5391 mtx_unlock(&sync_mtx);
5392 BO_UNLOCK(bo);
5393
5394 return (0);
5395 }
5396
5397 int
vn_need_pageq_flush(struct vnode * vp)5398 vn_need_pageq_flush(struct vnode *vp)
5399 {
5400 struct vm_object *obj;
5401
5402 obj = vp->v_object;
5403 return (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
5404 vm_object_mightbedirty(obj));
5405 }
5406
5407 /*
5408 * Check if vnode represents a disk device
5409 */
5410 bool
vn_isdisk_error(struct vnode * vp,int * errp)5411 vn_isdisk_error(struct vnode *vp, int *errp)
5412 {
5413 int error;
5414
5415 if (vp->v_type != VCHR) {
5416 error = ENOTBLK;
5417 goto out;
5418 }
5419 error = 0;
5420 dev_lock();
5421 if (vp->v_rdev == NULL)
5422 error = ENXIO;
5423 else if (vp->v_rdev->si_devsw == NULL)
5424 error = ENXIO;
5425 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
5426 error = ENOTBLK;
5427 dev_unlock();
5428 out:
5429 *errp = error;
5430 return (error == 0);
5431 }
5432
5433 bool
vn_isdisk(struct vnode * vp)5434 vn_isdisk(struct vnode *vp)
5435 {
5436 int error;
5437
5438 return (vn_isdisk_error(vp, &error));
5439 }
5440
5441 /*
5442 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see
5443 * the comment above cache_fplookup for details.
5444 */
5445 int
vaccess_vexec_smr(mode_t file_mode,uid_t file_uid,gid_t file_gid,struct ucred * cred)5446 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred)
5447 {
5448 int error;
5449
5450 VFS_SMR_ASSERT_ENTERED();
5451
5452 /* Check the owner. */
5453 if (cred->cr_uid == file_uid) {
5454 if (file_mode & S_IXUSR)
5455 return (0);
5456 goto out_error;
5457 }
5458
5459 /* Otherwise, check the groups (first match) */
5460 if (groupmember(file_gid, cred)) {
5461 if (file_mode & S_IXGRP)
5462 return (0);
5463 goto out_error;
5464 }
5465
5466 /* Otherwise, check everyone else. */
5467 if (file_mode & S_IXOTH)
5468 return (0);
5469 out_error:
5470 /*
5471 * Permission check failed, but it is possible denial will get overwritten
5472 * (e.g., when root is traversing through a 700 directory owned by someone
5473 * else).
5474 *
5475 * vaccess() calls priv_check_cred which in turn can descent into MAC
5476 * modules overriding this result. It's quite unclear what semantics
5477 * are allowed for them to operate, thus for safety we don't call them
5478 * from within the SMR section. This also means if any such modules
5479 * are present, we have to let the regular lookup decide.
5480 */
5481 error = priv_check_cred_vfs_lookup_nomac(cred);
5482 switch (error) {
5483 case 0:
5484 return (0);
5485 case EAGAIN:
5486 /*
5487 * MAC modules present.
5488 */
5489 return (EAGAIN);
5490 case EPERM:
5491 return (EACCES);
5492 default:
5493 return (error);
5494 }
5495 }
5496
5497 /*
5498 * Common filesystem object access control check routine. Accepts a
5499 * vnode's type, "mode", uid and gid, requested access mode, and credentials.
5500 * Returns 0 on success, or an errno on failure.
5501 */
5502 int
vaccess(__enum_uint8 (vtype)type,mode_t file_mode,uid_t file_uid,gid_t file_gid,accmode_t accmode,struct ucred * cred)5503 vaccess(__enum_uint8(vtype) type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
5504 accmode_t accmode, struct ucred *cred)
5505 {
5506 accmode_t dac_granted;
5507 accmode_t priv_granted;
5508
5509 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
5510 ("invalid bit in accmode"));
5511 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
5512 ("VAPPEND without VWRITE"));
5513
5514 /*
5515 * Look for a normal, non-privileged way to access the file/directory
5516 * as requested. If it exists, go with that.
5517 */
5518
5519 dac_granted = 0;
5520
5521 /* Check the owner. */
5522 if (cred->cr_uid == file_uid) {
5523 dac_granted |= VADMIN;
5524 if (file_mode & S_IXUSR)
5525 dac_granted |= VEXEC;
5526 if (file_mode & S_IRUSR)
5527 dac_granted |= VREAD;
5528 if (file_mode & S_IWUSR)
5529 dac_granted |= (VWRITE | VAPPEND);
5530
5531 if ((accmode & dac_granted) == accmode)
5532 return (0);
5533
5534 goto privcheck;
5535 }
5536
5537 /* Otherwise, check the groups (first match) */
5538 if (groupmember(file_gid, cred)) {
5539 if (file_mode & S_IXGRP)
5540 dac_granted |= VEXEC;
5541 if (file_mode & S_IRGRP)
5542 dac_granted |= VREAD;
5543 if (file_mode & S_IWGRP)
5544 dac_granted |= (VWRITE | VAPPEND);
5545
5546 if ((accmode & dac_granted) == accmode)
5547 return (0);
5548
5549 goto privcheck;
5550 }
5551
5552 /* Otherwise, check everyone else. */
5553 if (file_mode & S_IXOTH)
5554 dac_granted |= VEXEC;
5555 if (file_mode & S_IROTH)
5556 dac_granted |= VREAD;
5557 if (file_mode & S_IWOTH)
5558 dac_granted |= (VWRITE | VAPPEND);
5559 if ((accmode & dac_granted) == accmode)
5560 return (0);
5561
5562 privcheck:
5563 /*
5564 * Build a privilege mask to determine if the set of privileges
5565 * satisfies the requirements when combined with the granted mask
5566 * from above. For each privilege, if the privilege is required,
5567 * bitwise or the request type onto the priv_granted mask.
5568 */
5569 priv_granted = 0;
5570
5571 if (type == VDIR) {
5572 /*
5573 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
5574 * requests, instead of PRIV_VFS_EXEC.
5575 */
5576 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5577 !priv_check_cred(cred, PRIV_VFS_LOOKUP))
5578 priv_granted |= VEXEC;
5579 } else {
5580 /*
5581 * Ensure that at least one execute bit is on. Otherwise,
5582 * a privileged user will always succeed, and we don't want
5583 * this to happen unless the file really is executable.
5584 */
5585 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5586 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
5587 !priv_check_cred(cred, PRIV_VFS_EXEC))
5588 priv_granted |= VEXEC;
5589 }
5590
5591 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
5592 !priv_check_cred(cred, PRIV_VFS_READ))
5593 priv_granted |= VREAD;
5594
5595 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
5596 !priv_check_cred(cred, PRIV_VFS_WRITE))
5597 priv_granted |= (VWRITE | VAPPEND);
5598
5599 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
5600 !priv_check_cred(cred, PRIV_VFS_ADMIN))
5601 priv_granted |= VADMIN;
5602
5603 if ((accmode & (priv_granted | dac_granted)) == accmode) {
5604 return (0);
5605 }
5606
5607 return ((accmode & VADMIN) ? EPERM : EACCES);
5608 }
5609
5610 /*
5611 * Credential check based on process requesting service, and per-attribute
5612 * permissions.
5613 */
5614 int
extattr_check_cred(struct vnode * vp,int attrnamespace,struct ucred * cred,struct thread * td,accmode_t accmode)5615 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
5616 struct thread *td, accmode_t accmode)
5617 {
5618
5619 /*
5620 * Kernel-invoked always succeeds.
5621 */
5622 if (cred == NOCRED)
5623 return (0);
5624
5625 /*
5626 * Do not allow privileged processes in jail to directly manipulate
5627 * system attributes.
5628 */
5629 switch (attrnamespace) {
5630 case EXTATTR_NAMESPACE_SYSTEM:
5631 /* Potentially should be: return (EPERM); */
5632 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM));
5633 case EXTATTR_NAMESPACE_USER:
5634 return (VOP_ACCESS(vp, accmode, cred, td));
5635 default:
5636 return (EPERM);
5637 }
5638 }
5639
5640 #ifdef DEBUG_VFS_LOCKS
5641 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
5642 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
5643 "Drop into debugger on lock violation");
5644
5645 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
5646 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
5647 0, "Check for interlock across VOPs");
5648
5649 int vfs_badlock_print = 1; /* Print lock violations. */
5650 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
5651 0, "Print lock violations");
5652
5653 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
5654 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
5655 0, "Print vnode details on lock violations");
5656
5657 #ifdef KDB
5658 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
5659 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
5660 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
5661 #endif
5662
5663 static void
vfs_badlock(const char * msg,const char * str,struct vnode * vp)5664 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
5665 {
5666
5667 #ifdef KDB
5668 if (vfs_badlock_backtrace)
5669 kdb_backtrace();
5670 #endif
5671 if (vfs_badlock_vnode)
5672 vn_printf(vp, "vnode ");
5673 if (vfs_badlock_print)
5674 printf("%s: %p %s\n", str, (void *)vp, msg);
5675 if (vfs_badlock_ddb)
5676 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5677 }
5678
5679 void
assert_vi_locked(struct vnode * vp,const char * str)5680 assert_vi_locked(struct vnode *vp, const char *str)
5681 {
5682
5683 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
5684 vfs_badlock("interlock is not locked but should be", str, vp);
5685 }
5686
5687 void
assert_vi_unlocked(struct vnode * vp,const char * str)5688 assert_vi_unlocked(struct vnode *vp, const char *str)
5689 {
5690
5691 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
5692 vfs_badlock("interlock is locked but should not be", str, vp);
5693 }
5694
5695 void
assert_vop_locked(struct vnode * vp,const char * str)5696 assert_vop_locked(struct vnode *vp, const char *str)
5697 {
5698 if (KERNEL_PANICKED() || vp == NULL)
5699 return;
5700
5701 #ifdef WITNESS
5702 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5703 witness_is_owned(&vp->v_vnlock->lock_object) == -1)
5704 #else
5705 int locked = VOP_ISLOCKED(vp);
5706 if (locked == 0 || locked == LK_EXCLOTHER)
5707 #endif
5708 vfs_badlock("is not locked but should be", str, vp);
5709 }
5710
5711 void
assert_vop_unlocked(struct vnode * vp,const char * str)5712 assert_vop_unlocked(struct vnode *vp, const char *str)
5713 {
5714 if (KERNEL_PANICKED() || vp == NULL)
5715 return;
5716
5717 #ifdef WITNESS
5718 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5719 witness_is_owned(&vp->v_vnlock->lock_object) == 1)
5720 #else
5721 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
5722 #endif
5723 vfs_badlock("is locked but should not be", str, vp);
5724 }
5725
5726 void
assert_vop_elocked(struct vnode * vp,const char * str)5727 assert_vop_elocked(struct vnode *vp, const char *str)
5728 {
5729 if (KERNEL_PANICKED() || vp == NULL)
5730 return;
5731
5732 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
5733 vfs_badlock("is not exclusive locked but should be", str, vp);
5734 }
5735 #endif /* DEBUG_VFS_LOCKS */
5736
5737 void
vop_rename_fail(struct vop_rename_args * ap)5738 vop_rename_fail(struct vop_rename_args *ap)
5739 {
5740
5741 if (ap->a_tvp != NULL)
5742 vput(ap->a_tvp);
5743 if (ap->a_tdvp == ap->a_tvp)
5744 vrele(ap->a_tdvp);
5745 else
5746 vput(ap->a_tdvp);
5747 vrele(ap->a_fdvp);
5748 vrele(ap->a_fvp);
5749 }
5750
5751 void
vop_rename_pre(void * ap)5752 vop_rename_pre(void *ap)
5753 {
5754 struct vop_rename_args *a = ap;
5755
5756 #ifdef DEBUG_VFS_LOCKS
5757 if (a->a_tvp)
5758 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
5759 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
5760 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
5761 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
5762
5763 /* Check the source (from). */
5764 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
5765 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
5766 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
5767 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
5768 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
5769
5770 /* Check the target. */
5771 if (a->a_tvp)
5772 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
5773 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
5774 #endif
5775 /*
5776 * It may be tempting to add vn_seqc_write_begin/end calls here and
5777 * in vop_rename_post but that's not going to work out since some
5778 * filesystems relookup vnodes mid-rename. This is probably a bug.
5779 *
5780 * For now filesystems are expected to do the relevant calls after they
5781 * decide what vnodes to operate on.
5782 */
5783 if (a->a_tdvp != a->a_fdvp)
5784 vhold(a->a_fdvp);
5785 if (a->a_tvp != a->a_fvp)
5786 vhold(a->a_fvp);
5787 vhold(a->a_tdvp);
5788 if (a->a_tvp)
5789 vhold(a->a_tvp);
5790 }
5791
5792 #ifdef DEBUG_VFS_LOCKS
5793 void
vop_fplookup_vexec_debugpre(void * ap __unused)5794 vop_fplookup_vexec_debugpre(void *ap __unused)
5795 {
5796
5797 VFS_SMR_ASSERT_ENTERED();
5798 }
5799
5800 void
vop_fplookup_vexec_debugpost(void * ap,int rc)5801 vop_fplookup_vexec_debugpost(void *ap, int rc)
5802 {
5803 struct vop_fplookup_vexec_args *a;
5804 struct vnode *vp;
5805
5806 a = ap;
5807 vp = a->a_vp;
5808
5809 VFS_SMR_ASSERT_ENTERED();
5810 if (rc == EOPNOTSUPP)
5811 VNPASS(VN_IS_DOOMED(vp), vp);
5812 }
5813
5814 void
vop_fplookup_symlink_debugpre(void * ap __unused)5815 vop_fplookup_symlink_debugpre(void *ap __unused)
5816 {
5817
5818 VFS_SMR_ASSERT_ENTERED();
5819 }
5820
5821 void
vop_fplookup_symlink_debugpost(void * ap __unused,int rc __unused)5822 vop_fplookup_symlink_debugpost(void *ap __unused, int rc __unused)
5823 {
5824
5825 VFS_SMR_ASSERT_ENTERED();
5826 }
5827
5828 static void
vop_fsync_debugprepost(struct vnode * vp,const char * name)5829 vop_fsync_debugprepost(struct vnode *vp, const char *name)
5830 {
5831 if (vp->v_type == VCHR)
5832 ;
5833 /*
5834 * The shared vs. exclusive locking policy for fsync()
5835 * is actually determined by vp's write mount as indicated
5836 * by VOP_GETWRITEMOUNT(), which for stacked filesystems
5837 * may not be the same as vp->v_mount. However, if the
5838 * underlying filesystem which really handles the fsync()
5839 * supports shared locking, the stacked filesystem must also
5840 * be prepared for its VOP_FSYNC() operation to be called
5841 * with only a shared lock. On the other hand, if the
5842 * stacked filesystem claims support for shared write
5843 * locking but the underlying filesystem does not, and the
5844 * caller incorrectly uses a shared lock, this condition
5845 * should still be caught when the stacked filesystem
5846 * invokes VOP_FSYNC() on the underlying filesystem.
5847 */
5848 else if (MNT_SHARED_WRITES(vp->v_mount))
5849 ASSERT_VOP_LOCKED(vp, name);
5850 else
5851 ASSERT_VOP_ELOCKED(vp, name);
5852 }
5853
5854 void
vop_fsync_debugpre(void * a)5855 vop_fsync_debugpre(void *a)
5856 {
5857 struct vop_fsync_args *ap;
5858
5859 ap = a;
5860 vop_fsync_debugprepost(ap->a_vp, "fsync");
5861 }
5862
5863 void
vop_fsync_debugpost(void * a,int rc __unused)5864 vop_fsync_debugpost(void *a, int rc __unused)
5865 {
5866 struct vop_fsync_args *ap;
5867
5868 ap = a;
5869 vop_fsync_debugprepost(ap->a_vp, "fsync");
5870 }
5871
5872 void
vop_fdatasync_debugpre(void * a)5873 vop_fdatasync_debugpre(void *a)
5874 {
5875 struct vop_fdatasync_args *ap;
5876
5877 ap = a;
5878 vop_fsync_debugprepost(ap->a_vp, "fsync");
5879 }
5880
5881 void
vop_fdatasync_debugpost(void * a,int rc __unused)5882 vop_fdatasync_debugpost(void *a, int rc __unused)
5883 {
5884 struct vop_fdatasync_args *ap;
5885
5886 ap = a;
5887 vop_fsync_debugprepost(ap->a_vp, "fsync");
5888 }
5889
5890 void
vop_strategy_debugpre(void * ap)5891 vop_strategy_debugpre(void *ap)
5892 {
5893 struct vop_strategy_args *a;
5894 struct buf *bp;
5895
5896 a = ap;
5897 bp = a->a_bp;
5898
5899 /*
5900 * Cluster ops lock their component buffers but not the IO container.
5901 */
5902 if ((bp->b_flags & B_CLUSTER) != 0)
5903 return;
5904
5905 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) {
5906 if (vfs_badlock_print)
5907 printf(
5908 "VOP_STRATEGY: bp is not locked but should be\n");
5909 if (vfs_badlock_ddb)
5910 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5911 }
5912 }
5913
5914 void
vop_lock_debugpre(void * ap)5915 vop_lock_debugpre(void *ap)
5916 {
5917 struct vop_lock1_args *a = ap;
5918
5919 if ((a->a_flags & LK_INTERLOCK) == 0)
5920 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
5921 else
5922 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
5923 }
5924
5925 void
vop_lock_debugpost(void * ap,int rc)5926 vop_lock_debugpost(void *ap, int rc)
5927 {
5928 struct vop_lock1_args *a = ap;
5929
5930 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
5931 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
5932 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
5933 }
5934
5935 void
vop_unlock_debugpre(void * ap)5936 vop_unlock_debugpre(void *ap)
5937 {
5938 struct vop_unlock_args *a = ap;
5939 struct vnode *vp = a->a_vp;
5940
5941 VNPASS(vn_get_state(vp) != VSTATE_UNINITIALIZED, vp);
5942 ASSERT_VOP_LOCKED(vp, "VOP_UNLOCK");
5943 }
5944
5945 void
vop_need_inactive_debugpre(void * ap)5946 vop_need_inactive_debugpre(void *ap)
5947 {
5948 struct vop_need_inactive_args *a = ap;
5949
5950 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
5951 }
5952
5953 void
vop_need_inactive_debugpost(void * ap,int rc)5954 vop_need_inactive_debugpost(void *ap, int rc)
5955 {
5956 struct vop_need_inactive_args *a = ap;
5957
5958 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
5959 }
5960 #endif
5961
5962 void
vop_create_pre(void * ap)5963 vop_create_pre(void *ap)
5964 {
5965 struct vop_create_args *a;
5966 struct vnode *dvp;
5967
5968 a = ap;
5969 dvp = a->a_dvp;
5970 vn_seqc_write_begin(dvp);
5971 }
5972
5973 void
vop_create_post(void * ap,int rc)5974 vop_create_post(void *ap, int rc)
5975 {
5976 struct vop_create_args *a;
5977 struct vnode *dvp;
5978
5979 a = ap;
5980 dvp = a->a_dvp;
5981 vn_seqc_write_end(dvp);
5982 if (!rc)
5983 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
5984 }
5985
5986 void
vop_whiteout_pre(void * ap)5987 vop_whiteout_pre(void *ap)
5988 {
5989 struct vop_whiteout_args *a;
5990 struct vnode *dvp;
5991
5992 a = ap;
5993 dvp = a->a_dvp;
5994 vn_seqc_write_begin(dvp);
5995 }
5996
5997 void
vop_whiteout_post(void * ap,int rc)5998 vop_whiteout_post(void *ap, int rc)
5999 {
6000 struct vop_whiteout_args *a;
6001 struct vnode *dvp;
6002
6003 a = ap;
6004 dvp = a->a_dvp;
6005 vn_seqc_write_end(dvp);
6006 }
6007
6008 void
vop_deleteextattr_pre(void * ap)6009 vop_deleteextattr_pre(void *ap)
6010 {
6011 struct vop_deleteextattr_args *a;
6012 struct vnode *vp;
6013
6014 a = ap;
6015 vp = a->a_vp;
6016 vn_seqc_write_begin(vp);
6017 }
6018
6019 void
vop_deleteextattr_post(void * ap,int rc)6020 vop_deleteextattr_post(void *ap, int rc)
6021 {
6022 struct vop_deleteextattr_args *a;
6023 struct vnode *vp;
6024
6025 a = ap;
6026 vp = a->a_vp;
6027 vn_seqc_write_end(vp);
6028 if (!rc)
6029 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
6030 }
6031
6032 void
vop_link_pre(void * ap)6033 vop_link_pre(void *ap)
6034 {
6035 struct vop_link_args *a;
6036 struct vnode *vp, *tdvp;
6037
6038 a = ap;
6039 vp = a->a_vp;
6040 tdvp = a->a_tdvp;
6041 vn_seqc_write_begin(vp);
6042 vn_seqc_write_begin(tdvp);
6043 }
6044
6045 void
vop_link_post(void * ap,int rc)6046 vop_link_post(void *ap, int rc)
6047 {
6048 struct vop_link_args *a;
6049 struct vnode *vp, *tdvp;
6050
6051 a = ap;
6052 vp = a->a_vp;
6053 tdvp = a->a_tdvp;
6054 vn_seqc_write_end(vp);
6055 vn_seqc_write_end(tdvp);
6056 if (!rc) {
6057 VFS_KNOTE_LOCKED(vp, NOTE_LINK);
6058 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE);
6059 }
6060 }
6061
6062 void
vop_mkdir_pre(void * ap)6063 vop_mkdir_pre(void *ap)
6064 {
6065 struct vop_mkdir_args *a;
6066 struct vnode *dvp;
6067
6068 a = ap;
6069 dvp = a->a_dvp;
6070 vn_seqc_write_begin(dvp);
6071 }
6072
6073 void
vop_mkdir_post(void * ap,int rc)6074 vop_mkdir_post(void *ap, int rc)
6075 {
6076 struct vop_mkdir_args *a;
6077 struct vnode *dvp;
6078
6079 a = ap;
6080 dvp = a->a_dvp;
6081 vn_seqc_write_end(dvp);
6082 if (!rc)
6083 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6084 }
6085
6086 #ifdef DEBUG_VFS_LOCKS
6087 void
vop_mkdir_debugpost(void * ap,int rc)6088 vop_mkdir_debugpost(void *ap, int rc)
6089 {
6090 struct vop_mkdir_args *a;
6091
6092 a = ap;
6093 if (!rc)
6094 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp);
6095 }
6096 #endif
6097
6098 void
vop_mknod_pre(void * ap)6099 vop_mknod_pre(void *ap)
6100 {
6101 struct vop_mknod_args *a;
6102 struct vnode *dvp;
6103
6104 a = ap;
6105 dvp = a->a_dvp;
6106 vn_seqc_write_begin(dvp);
6107 }
6108
6109 void
vop_mknod_post(void * ap,int rc)6110 vop_mknod_post(void *ap, int rc)
6111 {
6112 struct vop_mknod_args *a;
6113 struct vnode *dvp;
6114
6115 a = ap;
6116 dvp = a->a_dvp;
6117 vn_seqc_write_end(dvp);
6118 if (!rc)
6119 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6120 }
6121
6122 void
vop_reclaim_post(void * ap,int rc)6123 vop_reclaim_post(void *ap, int rc)
6124 {
6125 struct vop_reclaim_args *a;
6126 struct vnode *vp;
6127
6128 a = ap;
6129 vp = a->a_vp;
6130 ASSERT_VOP_IN_SEQC(vp);
6131 if (!rc)
6132 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE);
6133 }
6134
6135 void
vop_remove_pre(void * ap)6136 vop_remove_pre(void *ap)
6137 {
6138 struct vop_remove_args *a;
6139 struct vnode *dvp, *vp;
6140
6141 a = ap;
6142 dvp = a->a_dvp;
6143 vp = a->a_vp;
6144 vn_seqc_write_begin(dvp);
6145 vn_seqc_write_begin(vp);
6146 }
6147
6148 void
vop_remove_post(void * ap,int rc)6149 vop_remove_post(void *ap, int rc)
6150 {
6151 struct vop_remove_args *a;
6152 struct vnode *dvp, *vp;
6153
6154 a = ap;
6155 dvp = a->a_dvp;
6156 vp = a->a_vp;
6157 vn_seqc_write_end(dvp);
6158 vn_seqc_write_end(vp);
6159 if (!rc) {
6160 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6161 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6162 }
6163 }
6164
6165 void
vop_rename_post(void * ap,int rc)6166 vop_rename_post(void *ap, int rc)
6167 {
6168 struct vop_rename_args *a = ap;
6169 long hint;
6170
6171 if (!rc) {
6172 hint = NOTE_WRITE;
6173 if (a->a_fdvp == a->a_tdvp) {
6174 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
6175 hint |= NOTE_LINK;
6176 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6177 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6178 } else {
6179 hint |= NOTE_EXTEND;
6180 if (a->a_fvp->v_type == VDIR)
6181 hint |= NOTE_LINK;
6182 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6183
6184 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
6185 a->a_tvp->v_type == VDIR)
6186 hint &= ~NOTE_LINK;
6187 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6188 }
6189
6190 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
6191 if (a->a_tvp)
6192 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
6193 }
6194 if (a->a_tdvp != a->a_fdvp)
6195 vdrop(a->a_fdvp);
6196 if (a->a_tvp != a->a_fvp)
6197 vdrop(a->a_fvp);
6198 vdrop(a->a_tdvp);
6199 if (a->a_tvp)
6200 vdrop(a->a_tvp);
6201 }
6202
6203 void
vop_rmdir_pre(void * ap)6204 vop_rmdir_pre(void *ap)
6205 {
6206 struct vop_rmdir_args *a;
6207 struct vnode *dvp, *vp;
6208
6209 a = ap;
6210 dvp = a->a_dvp;
6211 vp = a->a_vp;
6212 vn_seqc_write_begin(dvp);
6213 vn_seqc_write_begin(vp);
6214 }
6215
6216 void
vop_rmdir_post(void * ap,int rc)6217 vop_rmdir_post(void *ap, int rc)
6218 {
6219 struct vop_rmdir_args *a;
6220 struct vnode *dvp, *vp;
6221
6222 a = ap;
6223 dvp = a->a_dvp;
6224 vp = a->a_vp;
6225 vn_seqc_write_end(dvp);
6226 vn_seqc_write_end(vp);
6227 if (!rc) {
6228 vp->v_vflag |= VV_UNLINKED;
6229 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6230 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6231 }
6232 }
6233
6234 void
vop_setattr_pre(void * ap)6235 vop_setattr_pre(void *ap)
6236 {
6237 struct vop_setattr_args *a;
6238 struct vnode *vp;
6239
6240 a = ap;
6241 vp = a->a_vp;
6242 vn_seqc_write_begin(vp);
6243 }
6244
6245 void
vop_setattr_post(void * ap,int rc)6246 vop_setattr_post(void *ap, int rc)
6247 {
6248 struct vop_setattr_args *a;
6249 struct vnode *vp;
6250
6251 a = ap;
6252 vp = a->a_vp;
6253 vn_seqc_write_end(vp);
6254 if (!rc)
6255 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6256 }
6257
6258 void
vop_setacl_pre(void * ap)6259 vop_setacl_pre(void *ap)
6260 {
6261 struct vop_setacl_args *a;
6262 struct vnode *vp;
6263
6264 a = ap;
6265 vp = a->a_vp;
6266 vn_seqc_write_begin(vp);
6267 }
6268
6269 void
vop_setacl_post(void * ap,int rc __unused)6270 vop_setacl_post(void *ap, int rc __unused)
6271 {
6272 struct vop_setacl_args *a;
6273 struct vnode *vp;
6274
6275 a = ap;
6276 vp = a->a_vp;
6277 vn_seqc_write_end(vp);
6278 }
6279
6280 void
vop_setextattr_pre(void * ap)6281 vop_setextattr_pre(void *ap)
6282 {
6283 struct vop_setextattr_args *a;
6284 struct vnode *vp;
6285
6286 a = ap;
6287 vp = a->a_vp;
6288 vn_seqc_write_begin(vp);
6289 }
6290
6291 void
vop_setextattr_post(void * ap,int rc)6292 vop_setextattr_post(void *ap, int rc)
6293 {
6294 struct vop_setextattr_args *a;
6295 struct vnode *vp;
6296
6297 a = ap;
6298 vp = a->a_vp;
6299 vn_seqc_write_end(vp);
6300 if (!rc)
6301 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6302 }
6303
6304 void
vop_symlink_pre(void * ap)6305 vop_symlink_pre(void *ap)
6306 {
6307 struct vop_symlink_args *a;
6308 struct vnode *dvp;
6309
6310 a = ap;
6311 dvp = a->a_dvp;
6312 vn_seqc_write_begin(dvp);
6313 }
6314
6315 void
vop_symlink_post(void * ap,int rc)6316 vop_symlink_post(void *ap, int rc)
6317 {
6318 struct vop_symlink_args *a;
6319 struct vnode *dvp;
6320
6321 a = ap;
6322 dvp = a->a_dvp;
6323 vn_seqc_write_end(dvp);
6324 if (!rc)
6325 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6326 }
6327
6328 void
vop_open_post(void * ap,int rc)6329 vop_open_post(void *ap, int rc)
6330 {
6331 struct vop_open_args *a = ap;
6332
6333 if (!rc)
6334 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
6335 }
6336
6337 void
vop_close_post(void * ap,int rc)6338 vop_close_post(void *ap, int rc)
6339 {
6340 struct vop_close_args *a = ap;
6341
6342 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
6343 !VN_IS_DOOMED(a->a_vp))) {
6344 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
6345 NOTE_CLOSE_WRITE : NOTE_CLOSE);
6346 }
6347 }
6348
6349 void
vop_read_post(void * ap,int rc)6350 vop_read_post(void *ap, int rc)
6351 {
6352 struct vop_read_args *a = ap;
6353
6354 if (!rc)
6355 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6356 }
6357
6358 void
vop_read_pgcache_post(void * ap,int rc)6359 vop_read_pgcache_post(void *ap, int rc)
6360 {
6361 struct vop_read_pgcache_args *a = ap;
6362
6363 if (!rc)
6364 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ);
6365 }
6366
6367 void
vop_readdir_post(void * ap,int rc)6368 vop_readdir_post(void *ap, int rc)
6369 {
6370 struct vop_readdir_args *a = ap;
6371
6372 if (!rc)
6373 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6374 }
6375
6376 static struct knlist fs_knlist;
6377
6378 static void
vfs_event_init(void * arg)6379 vfs_event_init(void *arg)
6380 {
6381 knlist_init_mtx(&fs_knlist, NULL);
6382 }
6383 /* XXX - correct order? */
6384 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
6385
6386 void
vfs_event_signal(fsid_t * fsid,uint32_t event,intptr_t data __unused)6387 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
6388 {
6389
6390 KNOTE_UNLOCKED(&fs_knlist, event);
6391 }
6392
6393 static int filt_fsattach(struct knote *kn);
6394 static void filt_fsdetach(struct knote *kn);
6395 static int filt_fsevent(struct knote *kn, long hint);
6396
6397 struct filterops fs_filtops = {
6398 .f_isfd = 0,
6399 .f_attach = filt_fsattach,
6400 .f_detach = filt_fsdetach,
6401 .f_event = filt_fsevent
6402 };
6403
6404 static int
filt_fsattach(struct knote * kn)6405 filt_fsattach(struct knote *kn)
6406 {
6407
6408 kn->kn_flags |= EV_CLEAR;
6409 knlist_add(&fs_knlist, kn, 0);
6410 return (0);
6411 }
6412
6413 static void
filt_fsdetach(struct knote * kn)6414 filt_fsdetach(struct knote *kn)
6415 {
6416
6417 knlist_remove(&fs_knlist, kn, 0);
6418 }
6419
6420 static int
filt_fsevent(struct knote * kn,long hint)6421 filt_fsevent(struct knote *kn, long hint)
6422 {
6423
6424 kn->kn_fflags |= kn->kn_sfflags & hint;
6425
6426 return (kn->kn_fflags != 0);
6427 }
6428
6429 static int
sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)6430 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
6431 {
6432 struct vfsidctl vc;
6433 int error;
6434 struct mount *mp;
6435
6436 error = SYSCTL_IN(req, &vc, sizeof(vc));
6437 if (error)
6438 return (error);
6439 if (vc.vc_vers != VFS_CTL_VERS1)
6440 return (EINVAL);
6441 mp = vfs_getvfs(&vc.vc_fsid);
6442 if (mp == NULL)
6443 return (ENOENT);
6444 /* ensure that a specific sysctl goes to the right filesystem. */
6445 if (strcmp(vc.vc_fstypename, "*") != 0 &&
6446 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
6447 vfs_rel(mp);
6448 return (EINVAL);
6449 }
6450 VCTLTOREQ(&vc, req);
6451 error = VFS_SYSCTL(mp, vc.vc_op, req);
6452 vfs_rel(mp);
6453 return (error);
6454 }
6455
6456 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR,
6457 NULL, 0, sysctl_vfs_ctl, "",
6458 "Sysctl by fsid");
6459
6460 /*
6461 * Function to initialize a va_filerev field sensibly.
6462 * XXX: Wouldn't a random number make a lot more sense ??
6463 */
6464 u_quad_t
init_va_filerev(void)6465 init_va_filerev(void)
6466 {
6467 struct bintime bt;
6468
6469 getbinuptime(&bt);
6470 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
6471 }
6472
6473 static int filt_vfsread(struct knote *kn, long hint);
6474 static int filt_vfswrite(struct knote *kn, long hint);
6475 static int filt_vfsvnode(struct knote *kn, long hint);
6476 static void filt_vfsdetach(struct knote *kn);
6477 static struct filterops vfsread_filtops = {
6478 .f_isfd = 1,
6479 .f_detach = filt_vfsdetach,
6480 .f_event = filt_vfsread
6481 };
6482 static struct filterops vfswrite_filtops = {
6483 .f_isfd = 1,
6484 .f_detach = filt_vfsdetach,
6485 .f_event = filt_vfswrite
6486 };
6487 static struct filterops vfsvnode_filtops = {
6488 .f_isfd = 1,
6489 .f_detach = filt_vfsdetach,
6490 .f_event = filt_vfsvnode
6491 };
6492
6493 static void
vfs_knllock(void * arg)6494 vfs_knllock(void *arg)
6495 {
6496 struct vnode *vp = arg;
6497
6498 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
6499 }
6500
6501 static void
vfs_knlunlock(void * arg)6502 vfs_knlunlock(void *arg)
6503 {
6504 struct vnode *vp = arg;
6505
6506 VOP_UNLOCK(vp);
6507 }
6508
6509 static void
vfs_knl_assert_lock(void * arg,int what)6510 vfs_knl_assert_lock(void *arg, int what)
6511 {
6512 #ifdef DEBUG_VFS_LOCKS
6513 struct vnode *vp = arg;
6514
6515 if (what == LA_LOCKED)
6516 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
6517 else
6518 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
6519 #endif
6520 }
6521
6522 int
vfs_kqfilter(struct vop_kqfilter_args * ap)6523 vfs_kqfilter(struct vop_kqfilter_args *ap)
6524 {
6525 struct vnode *vp = ap->a_vp;
6526 struct knote *kn = ap->a_kn;
6527 struct knlist *knl;
6528
6529 KASSERT(vp->v_type != VFIFO || (kn->kn_filter != EVFILT_READ &&
6530 kn->kn_filter != EVFILT_WRITE),
6531 ("READ/WRITE filter on a FIFO leaked through"));
6532 switch (kn->kn_filter) {
6533 case EVFILT_READ:
6534 kn->kn_fop = &vfsread_filtops;
6535 break;
6536 case EVFILT_WRITE:
6537 kn->kn_fop = &vfswrite_filtops;
6538 break;
6539 case EVFILT_VNODE:
6540 kn->kn_fop = &vfsvnode_filtops;
6541 break;
6542 default:
6543 return (EINVAL);
6544 }
6545
6546 kn->kn_hook = (caddr_t)vp;
6547
6548 v_addpollinfo(vp);
6549 if (vp->v_pollinfo == NULL)
6550 return (ENOMEM);
6551 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
6552 vhold(vp);
6553 knlist_add(knl, kn, 0);
6554
6555 return (0);
6556 }
6557
6558 /*
6559 * Detach knote from vnode
6560 */
6561 static void
filt_vfsdetach(struct knote * kn)6562 filt_vfsdetach(struct knote *kn)
6563 {
6564 struct vnode *vp = (struct vnode *)kn->kn_hook;
6565
6566 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
6567 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
6568 vdrop(vp);
6569 }
6570
6571 /*ARGSUSED*/
6572 static int
filt_vfsread(struct knote * kn,long hint)6573 filt_vfsread(struct knote *kn, long hint)
6574 {
6575 struct vnode *vp = (struct vnode *)kn->kn_hook;
6576 off_t size;
6577 int res;
6578
6579 /*
6580 * filesystem is gone, so set the EOF flag and schedule
6581 * the knote for deletion.
6582 */
6583 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6584 VI_LOCK(vp);
6585 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6586 VI_UNLOCK(vp);
6587 return (1);
6588 }
6589
6590 if (vn_getsize_locked(vp, &size, curthread->td_ucred) != 0)
6591 return (0);
6592
6593 VI_LOCK(vp);
6594 kn->kn_data = size - kn->kn_fp->f_offset;
6595 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
6596 VI_UNLOCK(vp);
6597 return (res);
6598 }
6599
6600 /*ARGSUSED*/
6601 static int
filt_vfswrite(struct knote * kn,long hint)6602 filt_vfswrite(struct knote *kn, long hint)
6603 {
6604 struct vnode *vp = (struct vnode *)kn->kn_hook;
6605
6606 VI_LOCK(vp);
6607
6608 /*
6609 * filesystem is gone, so set the EOF flag and schedule
6610 * the knote for deletion.
6611 */
6612 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
6613 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6614
6615 kn->kn_data = 0;
6616 VI_UNLOCK(vp);
6617 return (1);
6618 }
6619
6620 static int
filt_vfsvnode(struct knote * kn,long hint)6621 filt_vfsvnode(struct knote *kn, long hint)
6622 {
6623 struct vnode *vp = (struct vnode *)kn->kn_hook;
6624 int res;
6625
6626 VI_LOCK(vp);
6627 if (kn->kn_sfflags & hint)
6628 kn->kn_fflags |= hint;
6629 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6630 kn->kn_flags |= EV_EOF;
6631 VI_UNLOCK(vp);
6632 return (1);
6633 }
6634 res = (kn->kn_fflags != 0);
6635 VI_UNLOCK(vp);
6636 return (res);
6637 }
6638
6639 int
vfs_read_dirent(struct vop_readdir_args * ap,struct dirent * dp,off_t off)6640 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
6641 {
6642 int error;
6643
6644 if (dp->d_reclen > ap->a_uio->uio_resid)
6645 return (ENAMETOOLONG);
6646 error = uiomove(dp, dp->d_reclen, ap->a_uio);
6647 if (error) {
6648 if (ap->a_ncookies != NULL) {
6649 if (ap->a_cookies != NULL)
6650 free(ap->a_cookies, M_TEMP);
6651 ap->a_cookies = NULL;
6652 *ap->a_ncookies = 0;
6653 }
6654 return (error);
6655 }
6656 if (ap->a_ncookies == NULL)
6657 return (0);
6658
6659 KASSERT(ap->a_cookies,
6660 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
6661
6662 *ap->a_cookies = realloc(*ap->a_cookies,
6663 (*ap->a_ncookies + 1) * sizeof(uint64_t), M_TEMP, M_WAITOK | M_ZERO);
6664 (*ap->a_cookies)[*ap->a_ncookies] = off;
6665 *ap->a_ncookies += 1;
6666 return (0);
6667 }
6668
6669 /*
6670 * The purpose of this routine is to remove granularity from accmode_t,
6671 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
6672 * VADMIN and VAPPEND.
6673 *
6674 * If it returns 0, the caller is supposed to continue with the usual
6675 * access checks using 'accmode' as modified by this routine. If it
6676 * returns nonzero value, the caller is supposed to return that value
6677 * as errno.
6678 *
6679 * Note that after this routine runs, accmode may be zero.
6680 */
6681 int
vfs_unixify_accmode(accmode_t * accmode)6682 vfs_unixify_accmode(accmode_t *accmode)
6683 {
6684 /*
6685 * There is no way to specify explicit "deny" rule using
6686 * file mode or POSIX.1e ACLs.
6687 */
6688 if (*accmode & VEXPLICIT_DENY) {
6689 *accmode = 0;
6690 return (0);
6691 }
6692
6693 /*
6694 * None of these can be translated into usual access bits.
6695 * Also, the common case for NFSv4 ACLs is to not contain
6696 * either of these bits. Caller should check for VWRITE
6697 * on the containing directory instead.
6698 */
6699 if (*accmode & (VDELETE_CHILD | VDELETE))
6700 return (EPERM);
6701
6702 if (*accmode & VADMIN_PERMS) {
6703 *accmode &= ~VADMIN_PERMS;
6704 *accmode |= VADMIN;
6705 }
6706
6707 /*
6708 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
6709 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
6710 */
6711 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
6712
6713 return (0);
6714 }
6715
6716 /*
6717 * Clear out a doomed vnode (if any) and replace it with a new one as long
6718 * as the fs is not being unmounted. Return the root vnode to the caller.
6719 */
6720 static int __noinline
vfs_cache_root_fallback(struct mount * mp,int flags,struct vnode ** vpp)6721 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp)
6722 {
6723 struct vnode *vp;
6724 int error;
6725
6726 restart:
6727 if (mp->mnt_rootvnode != NULL) {
6728 MNT_ILOCK(mp);
6729 vp = mp->mnt_rootvnode;
6730 if (vp != NULL) {
6731 if (!VN_IS_DOOMED(vp)) {
6732 vrefact(vp);
6733 MNT_IUNLOCK(mp);
6734 error = vn_lock(vp, flags);
6735 if (error == 0) {
6736 *vpp = vp;
6737 return (0);
6738 }
6739 vrele(vp);
6740 goto restart;
6741 }
6742 /*
6743 * Clear the old one.
6744 */
6745 mp->mnt_rootvnode = NULL;
6746 }
6747 MNT_IUNLOCK(mp);
6748 if (vp != NULL) {
6749 vfs_op_barrier_wait(mp);
6750 vrele(vp);
6751 }
6752 }
6753 error = VFS_CACHEDROOT(mp, flags, vpp);
6754 if (error != 0)
6755 return (error);
6756 if (mp->mnt_vfs_ops == 0) {
6757 MNT_ILOCK(mp);
6758 if (mp->mnt_vfs_ops != 0) {
6759 MNT_IUNLOCK(mp);
6760 return (0);
6761 }
6762 if (mp->mnt_rootvnode == NULL) {
6763 vrefact(*vpp);
6764 mp->mnt_rootvnode = *vpp;
6765 } else {
6766 if (mp->mnt_rootvnode != *vpp) {
6767 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) {
6768 panic("%s: mismatch between vnode returned "
6769 " by VFS_CACHEDROOT and the one cached "
6770 " (%p != %p)",
6771 __func__, *vpp, mp->mnt_rootvnode);
6772 }
6773 }
6774 }
6775 MNT_IUNLOCK(mp);
6776 }
6777 return (0);
6778 }
6779
6780 int
vfs_cache_root(struct mount * mp,int flags,struct vnode ** vpp)6781 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp)
6782 {
6783 struct mount_pcpu *mpcpu;
6784 struct vnode *vp;
6785 int error;
6786
6787 if (!vfs_op_thread_enter(mp, mpcpu))
6788 return (vfs_cache_root_fallback(mp, flags, vpp));
6789 vp = atomic_load_ptr(&mp->mnt_rootvnode);
6790 if (vp == NULL || VN_IS_DOOMED(vp)) {
6791 vfs_op_thread_exit(mp, mpcpu);
6792 return (vfs_cache_root_fallback(mp, flags, vpp));
6793 }
6794 vrefact(vp);
6795 vfs_op_thread_exit(mp, mpcpu);
6796 error = vn_lock(vp, flags);
6797 if (error != 0) {
6798 vrele(vp);
6799 return (vfs_cache_root_fallback(mp, flags, vpp));
6800 }
6801 *vpp = vp;
6802 return (0);
6803 }
6804
6805 struct vnode *
vfs_cache_root_clear(struct mount * mp)6806 vfs_cache_root_clear(struct mount *mp)
6807 {
6808 struct vnode *vp;
6809
6810 /*
6811 * ops > 0 guarantees there is nobody who can see this vnode
6812 */
6813 MPASS(mp->mnt_vfs_ops > 0);
6814 vp = mp->mnt_rootvnode;
6815 if (vp != NULL)
6816 vn_seqc_write_begin(vp);
6817 mp->mnt_rootvnode = NULL;
6818 return (vp);
6819 }
6820
6821 void
vfs_cache_root_set(struct mount * mp,struct vnode * vp)6822 vfs_cache_root_set(struct mount *mp, struct vnode *vp)
6823 {
6824
6825 MPASS(mp->mnt_vfs_ops > 0);
6826 vrefact(vp);
6827 mp->mnt_rootvnode = vp;
6828 }
6829
6830 /*
6831 * These are helper functions for filesystems to traverse all
6832 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
6833 *
6834 * This interface replaces MNT_VNODE_FOREACH.
6835 */
6836
6837 struct vnode *
__mnt_vnode_next_all(struct vnode ** mvp,struct mount * mp)6838 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
6839 {
6840 struct vnode *vp;
6841
6842 maybe_yield();
6843 MNT_ILOCK(mp);
6844 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6845 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL;
6846 vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
6847 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
6848 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
6849 continue;
6850 VI_LOCK(vp);
6851 if (VN_IS_DOOMED(vp)) {
6852 VI_UNLOCK(vp);
6853 continue;
6854 }
6855 break;
6856 }
6857 if (vp == NULL) {
6858 __mnt_vnode_markerfree_all(mvp, mp);
6859 /* MNT_IUNLOCK(mp); -- done in above function */
6860 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
6861 return (NULL);
6862 }
6863 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
6864 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
6865 MNT_IUNLOCK(mp);
6866 return (vp);
6867 }
6868
6869 struct vnode *
__mnt_vnode_first_all(struct vnode ** mvp,struct mount * mp)6870 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
6871 {
6872 struct vnode *vp;
6873
6874 *mvp = vn_alloc_marker(mp);
6875 MNT_ILOCK(mp);
6876 MNT_REF(mp);
6877
6878 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
6879 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
6880 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
6881 continue;
6882 VI_LOCK(vp);
6883 if (VN_IS_DOOMED(vp)) {
6884 VI_UNLOCK(vp);
6885 continue;
6886 }
6887 break;
6888 }
6889 if (vp == NULL) {
6890 MNT_REL(mp);
6891 MNT_IUNLOCK(mp);
6892 vn_free_marker(*mvp);
6893 *mvp = NULL;
6894 return (NULL);
6895 }
6896 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
6897 MNT_IUNLOCK(mp);
6898 return (vp);
6899 }
6900
6901 void
__mnt_vnode_markerfree_all(struct vnode ** mvp,struct mount * mp)6902 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
6903 {
6904
6905 if (*mvp == NULL) {
6906 MNT_IUNLOCK(mp);
6907 return;
6908 }
6909
6910 mtx_assert(MNT_MTX(mp), MA_OWNED);
6911
6912 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6913 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
6914 MNT_REL(mp);
6915 MNT_IUNLOCK(mp);
6916 vn_free_marker(*mvp);
6917 *mvp = NULL;
6918 }
6919
6920 /*
6921 * These are helper functions for filesystems to traverse their
6922 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h
6923 */
6924 static void
mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)6925 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
6926 {
6927
6928 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6929
6930 MNT_ILOCK(mp);
6931 MNT_REL(mp);
6932 MNT_IUNLOCK(mp);
6933 vn_free_marker(*mvp);
6934 *mvp = NULL;
6935 }
6936
6937 /*
6938 * Relock the mp mount vnode list lock with the vp vnode interlock in the
6939 * conventional lock order during mnt_vnode_next_lazy iteration.
6940 *
6941 * On entry, the mount vnode list lock is held and the vnode interlock is not.
6942 * The list lock is dropped and reacquired. On success, both locks are held.
6943 * On failure, the mount vnode list lock is held but the vnode interlock is
6944 * not, and the procedure may have yielded.
6945 */
6946 static bool
mnt_vnode_next_lazy_relock(struct vnode * mvp,struct mount * mp,struct vnode * vp)6947 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp,
6948 struct vnode *vp)
6949 {
6950
6951 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER &&
6952 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp,
6953 ("%s: bad marker", __func__));
6954 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp,
6955 ("%s: inappropriate vnode", __func__));
6956 ASSERT_VI_UNLOCKED(vp, __func__);
6957 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
6958
6959 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist);
6960 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist);
6961
6962 /*
6963 * Note we may be racing against vdrop which transitioned the hold
6964 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine,
6965 * if we are the only user after we get the interlock we will just
6966 * vdrop.
6967 */
6968 vhold(vp);
6969 mtx_unlock(&mp->mnt_listmtx);
6970 VI_LOCK(vp);
6971 if (VN_IS_DOOMED(vp)) {
6972 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
6973 goto out_lost;
6974 }
6975 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
6976 /*
6977 * There is nothing to do if we are the last user.
6978 */
6979 if (!refcount_release_if_not_last(&vp->v_holdcnt))
6980 goto out_lost;
6981 mtx_lock(&mp->mnt_listmtx);
6982 return (true);
6983 out_lost:
6984 vdropl(vp);
6985 maybe_yield();
6986 mtx_lock(&mp->mnt_listmtx);
6987 return (false);
6988 }
6989
6990 static struct vnode *
mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)6991 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
6992 void *cbarg)
6993 {
6994 struct vnode *vp;
6995
6996 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
6997 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6998 restart:
6999 vp = TAILQ_NEXT(*mvp, v_lazylist);
7000 while (vp != NULL) {
7001 if (vp->v_type == VMARKER) {
7002 vp = TAILQ_NEXT(vp, v_lazylist);
7003 continue;
7004 }
7005 /*
7006 * See if we want to process the vnode. Note we may encounter a
7007 * long string of vnodes we don't care about and hog the list
7008 * as a result. Check for it and requeue the marker.
7009 */
7010 VNPASS(!VN_IS_DOOMED(vp), vp);
7011 if (!cb(vp, cbarg)) {
7012 if (!should_yield()) {
7013 vp = TAILQ_NEXT(vp, v_lazylist);
7014 continue;
7015 }
7016 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp,
7017 v_lazylist);
7018 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp,
7019 v_lazylist);
7020 mtx_unlock(&mp->mnt_listmtx);
7021 kern_yield(PRI_USER);
7022 mtx_lock(&mp->mnt_listmtx);
7023 goto restart;
7024 }
7025 /*
7026 * Try-lock because this is the wrong lock order.
7027 */
7028 if (!VI_TRYLOCK(vp) &&
7029 !mnt_vnode_next_lazy_relock(*mvp, mp, vp))
7030 goto restart;
7031 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
7032 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
7033 ("alien vnode on the lazy list %p %p", vp, mp));
7034 VNPASS(vp->v_mount == mp, vp);
7035 VNPASS(!VN_IS_DOOMED(vp), vp);
7036 break;
7037 }
7038 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7039
7040 /* Check if we are done */
7041 if (vp == NULL) {
7042 mtx_unlock(&mp->mnt_listmtx);
7043 mnt_vnode_markerfree_lazy(mvp, mp);
7044 return (NULL);
7045 }
7046 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist);
7047 mtx_unlock(&mp->mnt_listmtx);
7048 ASSERT_VI_LOCKED(vp, "lazy iter");
7049 return (vp);
7050 }
7051
7052 struct vnode *
__mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7053 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7054 void *cbarg)
7055 {
7056
7057 maybe_yield();
7058 mtx_lock(&mp->mnt_listmtx);
7059 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7060 }
7061
7062 struct vnode *
__mnt_vnode_first_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7063 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7064 void *cbarg)
7065 {
7066 struct vnode *vp;
7067
7068 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist))
7069 return (NULL);
7070
7071 *mvp = vn_alloc_marker(mp);
7072 MNT_ILOCK(mp);
7073 MNT_REF(mp);
7074 MNT_IUNLOCK(mp);
7075
7076 mtx_lock(&mp->mnt_listmtx);
7077 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist);
7078 if (vp == NULL) {
7079 mtx_unlock(&mp->mnt_listmtx);
7080 mnt_vnode_markerfree_lazy(mvp, mp);
7081 return (NULL);
7082 }
7083 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist);
7084 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7085 }
7086
7087 void
__mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)7088 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
7089 {
7090
7091 if (*mvp == NULL)
7092 return;
7093
7094 mtx_lock(&mp->mnt_listmtx);
7095 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7096 mtx_unlock(&mp->mnt_listmtx);
7097 mnt_vnode_markerfree_lazy(mvp, mp);
7098 }
7099
7100 int
vn_dir_check_exec(struct vnode * vp,struct componentname * cnp)7101 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp)
7102 {
7103
7104 if ((cnp->cn_flags & NOEXECCHECK) != 0) {
7105 cnp->cn_flags &= ~NOEXECCHECK;
7106 return (0);
7107 }
7108
7109 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, curthread));
7110 }
7111
7112 /*
7113 * Do not use this variant unless you have means other than the hold count
7114 * to prevent the vnode from getting freed.
7115 */
7116 void
vn_seqc_write_begin_locked(struct vnode * vp)7117 vn_seqc_write_begin_locked(struct vnode *vp)
7118 {
7119
7120 ASSERT_VI_LOCKED(vp, __func__);
7121 VNPASS(vp->v_holdcnt > 0, vp);
7122 VNPASS(vp->v_seqc_users >= 0, vp);
7123 vp->v_seqc_users++;
7124 if (vp->v_seqc_users == 1)
7125 seqc_sleepable_write_begin(&vp->v_seqc);
7126 }
7127
7128 void
vn_seqc_write_begin(struct vnode * vp)7129 vn_seqc_write_begin(struct vnode *vp)
7130 {
7131
7132 VI_LOCK(vp);
7133 vn_seqc_write_begin_locked(vp);
7134 VI_UNLOCK(vp);
7135 }
7136
7137 void
vn_seqc_write_end_locked(struct vnode * vp)7138 vn_seqc_write_end_locked(struct vnode *vp)
7139 {
7140
7141 ASSERT_VI_LOCKED(vp, __func__);
7142 VNPASS(vp->v_seqc_users > 0, vp);
7143 vp->v_seqc_users--;
7144 if (vp->v_seqc_users == 0)
7145 seqc_sleepable_write_end(&vp->v_seqc);
7146 }
7147
7148 void
vn_seqc_write_end(struct vnode * vp)7149 vn_seqc_write_end(struct vnode *vp)
7150 {
7151
7152 VI_LOCK(vp);
7153 vn_seqc_write_end_locked(vp);
7154 VI_UNLOCK(vp);
7155 }
7156
7157 /*
7158 * Special case handling for allocating and freeing vnodes.
7159 *
7160 * The counter remains unchanged on free so that a doomed vnode will
7161 * keep testing as in modify as long as it is accessible with SMR.
7162 */
7163 static void
vn_seqc_init(struct vnode * vp)7164 vn_seqc_init(struct vnode *vp)
7165 {
7166
7167 vp->v_seqc = 0;
7168 vp->v_seqc_users = 0;
7169 }
7170
7171 static void
vn_seqc_write_end_free(struct vnode * vp)7172 vn_seqc_write_end_free(struct vnode *vp)
7173 {
7174
7175 VNPASS(seqc_in_modify(vp->v_seqc), vp);
7176 VNPASS(vp->v_seqc_users == 1, vp);
7177 }
7178
7179 void
vn_irflag_set_locked(struct vnode * vp,short toset)7180 vn_irflag_set_locked(struct vnode *vp, short toset)
7181 {
7182 short flags;
7183
7184 ASSERT_VI_LOCKED(vp, __func__);
7185 flags = vn_irflag_read(vp);
7186 VNASSERT((flags & toset) == 0, vp,
7187 ("%s: some of the passed flags already set (have %d, passed %d)\n",
7188 __func__, flags, toset));
7189 atomic_store_short(&vp->v_irflag, flags | toset);
7190 }
7191
7192 void
vn_irflag_set(struct vnode * vp,short toset)7193 vn_irflag_set(struct vnode *vp, short toset)
7194 {
7195
7196 VI_LOCK(vp);
7197 vn_irflag_set_locked(vp, toset);
7198 VI_UNLOCK(vp);
7199 }
7200
7201 void
vn_irflag_set_cond_locked(struct vnode * vp,short toset)7202 vn_irflag_set_cond_locked(struct vnode *vp, short toset)
7203 {
7204 short flags;
7205
7206 ASSERT_VI_LOCKED(vp, __func__);
7207 flags = vn_irflag_read(vp);
7208 atomic_store_short(&vp->v_irflag, flags | toset);
7209 }
7210
7211 void
vn_irflag_set_cond(struct vnode * vp,short toset)7212 vn_irflag_set_cond(struct vnode *vp, short toset)
7213 {
7214
7215 VI_LOCK(vp);
7216 vn_irflag_set_cond_locked(vp, toset);
7217 VI_UNLOCK(vp);
7218 }
7219
7220 void
vn_irflag_unset_locked(struct vnode * vp,short tounset)7221 vn_irflag_unset_locked(struct vnode *vp, short tounset)
7222 {
7223 short flags;
7224
7225 ASSERT_VI_LOCKED(vp, __func__);
7226 flags = vn_irflag_read(vp);
7227 VNASSERT((flags & tounset) == tounset, vp,
7228 ("%s: some of the passed flags not set (have %d, passed %d)\n",
7229 __func__, flags, tounset));
7230 atomic_store_short(&vp->v_irflag, flags & ~tounset);
7231 }
7232
7233 void
vn_irflag_unset(struct vnode * vp,short tounset)7234 vn_irflag_unset(struct vnode *vp, short tounset)
7235 {
7236
7237 VI_LOCK(vp);
7238 vn_irflag_unset_locked(vp, tounset);
7239 VI_UNLOCK(vp);
7240 }
7241
7242 int
vn_getsize_locked(struct vnode * vp,off_t * size,struct ucred * cred)7243 vn_getsize_locked(struct vnode *vp, off_t *size, struct ucred *cred)
7244 {
7245 struct vattr vattr;
7246 int error;
7247
7248 ASSERT_VOP_LOCKED(vp, __func__);
7249 error = VOP_GETATTR(vp, &vattr, cred);
7250 if (__predict_true(error == 0)) {
7251 if (vattr.va_size <= OFF_MAX)
7252 *size = vattr.va_size;
7253 else
7254 error = EFBIG;
7255 }
7256 return (error);
7257 }
7258
7259 int
vn_getsize(struct vnode * vp,off_t * size,struct ucred * cred)7260 vn_getsize(struct vnode *vp, off_t *size, struct ucred *cred)
7261 {
7262 int error;
7263
7264 VOP_LOCK(vp, LK_SHARED);
7265 error = vn_getsize_locked(vp, size, cred);
7266 VOP_UNLOCK(vp);
7267 return (error);
7268 }
7269
7270 #ifdef INVARIANTS
7271 void
vn_set_state_validate(struct vnode * vp,__enum_uint8 (vstate)state)7272 vn_set_state_validate(struct vnode *vp, __enum_uint8(vstate) state)
7273 {
7274
7275 switch (vp->v_state) {
7276 case VSTATE_UNINITIALIZED:
7277 switch (state) {
7278 case VSTATE_CONSTRUCTED:
7279 case VSTATE_DESTROYING:
7280 return;
7281 default:
7282 break;
7283 }
7284 break;
7285 case VSTATE_CONSTRUCTED:
7286 ASSERT_VOP_ELOCKED(vp, __func__);
7287 switch (state) {
7288 case VSTATE_DESTROYING:
7289 return;
7290 default:
7291 break;
7292 }
7293 break;
7294 case VSTATE_DESTROYING:
7295 ASSERT_VOP_ELOCKED(vp, __func__);
7296 switch (state) {
7297 case VSTATE_DEAD:
7298 return;
7299 default:
7300 break;
7301 }
7302 break;
7303 case VSTATE_DEAD:
7304 switch (state) {
7305 case VSTATE_UNINITIALIZED:
7306 return;
7307 default:
7308 break;
7309 }
7310 break;
7311 }
7312
7313 vn_printf(vp, "invalid state transition %d -> %d\n", vp->v_state, state);
7314 panic("invalid state transition %d -> %d\n", vp->v_state, state);
7315 }
7316 #endif
7317