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 __read_mostly bool vnode_can_skip_requeue;
226 SYSCTL_BOOL(_vfs_vnode_param, OID_AUTO, can_skip_requeue, CTLFLAG_RW,
227 &vnode_can_skip_requeue, 0, "Is LRU requeue skippable");
228
229 static u_long deferred_inact;
230 SYSCTL_ULONG(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD,
231 &deferred_inact, 0, "Number of times inactive processing was deferred");
232
233 /* To keep more than one thread at a time from running vfs_getnewfsid */
234 static struct mtx mntid_mtx;
235
236 /*
237 * Lock for any access to the following:
238 * vnode_list
239 * numvnodes
240 * freevnodes
241 */
242 static struct mtx __exclusive_cache_line vnode_list_mtx;
243
244 /* Publicly exported FS */
245 struct nfs_public nfs_pub;
246
247 static uma_zone_t buf_trie_zone;
248 static smr_t buf_trie_smr;
249
250 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
251 static uma_zone_t vnode_zone;
252 MALLOC_DEFINE(M_VNODEPOLL, "VN POLL", "vnode poll");
253
254 __read_frequently smr_t vfs_smr;
255
256 /*
257 * The workitem queue.
258 *
259 * It is useful to delay writes of file data and filesystem metadata
260 * for tens of seconds so that quickly created and deleted files need
261 * not waste disk bandwidth being created and removed. To realize this,
262 * we append vnodes to a "workitem" queue. When running with a soft
263 * updates implementation, most pending metadata dependencies should
264 * not wait for more than a few seconds. Thus, mounted on block devices
265 * are delayed only about a half the time that file data is delayed.
266 * Similarly, directory updates are more critical, so are only delayed
267 * about a third the time that file data is delayed. Thus, there are
268 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
269 * one each second (driven off the filesystem syncer process). The
270 * syncer_delayno variable indicates the next queue that is to be processed.
271 * Items that need to be processed soon are placed in this queue:
272 *
273 * syncer_workitem_pending[syncer_delayno]
274 *
275 * A delay of fifteen seconds is done by placing the request fifteen
276 * entries later in the queue:
277 *
278 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
279 *
280 */
281 static int syncer_delayno;
282 static long syncer_mask;
283 LIST_HEAD(synclist, bufobj);
284 static struct synclist *syncer_workitem_pending;
285 /*
286 * The sync_mtx protects:
287 * bo->bo_synclist
288 * sync_vnode_count
289 * syncer_delayno
290 * syncer_state
291 * syncer_workitem_pending
292 * syncer_worklist_len
293 * rushjob
294 */
295 static struct mtx sync_mtx;
296 static struct cv sync_wakeup;
297
298 #define SYNCER_MAXDELAY 32
299 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
300 static int syncdelay = 30; /* max time to delay syncing data */
301 static int filedelay = 30; /* time to delay syncing files */
302 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
303 "Time to delay syncing files (in seconds)");
304 static int dirdelay = 29; /* time to delay syncing directories */
305 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
306 "Time to delay syncing directories (in seconds)");
307 static int metadelay = 28; /* time to delay syncing metadata */
308 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
309 "Time to delay syncing metadata (in seconds)");
310 static int rushjob; /* number of slots to run ASAP */
311 static int stat_rush_requests; /* number of times I/O speeded up */
312 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
313 "Number of times I/O speeded up (rush requests)");
314
315 #define VDBATCH_SIZE 8
316 struct vdbatch {
317 u_int index;
318 struct mtx lock;
319 struct vnode *tab[VDBATCH_SIZE];
320 };
321 DPCPU_DEFINE_STATIC(struct vdbatch, vd);
322
323 static void vdbatch_dequeue(struct vnode *vp);
324
325 /*
326 * When shutting down the syncer, run it at four times normal speed.
327 */
328 #define SYNCER_SHUTDOWN_SPEEDUP 4
329 static int sync_vnode_count;
330 static int syncer_worklist_len;
331 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
332 syncer_state;
333
334 /* Target for maximum number of vnodes. */
335 u_long desiredvnodes;
336 static u_long gapvnodes; /* gap between wanted and desired */
337 static u_long vhiwat; /* enough extras after expansion */
338 static u_long vlowat; /* minimal extras before expansion */
339 static bool vstir; /* nonzero to stir non-free vnodes */
340 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
341
342 static u_long vnlru_read_freevnodes(void);
343
344 /*
345 * Note that no attempt is made to sanitize these parameters.
346 */
347 static int
sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)348 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)
349 {
350 u_long val;
351 int error;
352
353 val = desiredvnodes;
354 error = sysctl_handle_long(oidp, &val, 0, req);
355 if (error != 0 || req->newptr == NULL)
356 return (error);
357
358 if (val == desiredvnodes)
359 return (0);
360 mtx_lock(&vnode_list_mtx);
361 desiredvnodes = val;
362 wantfreevnodes = desiredvnodes / 4;
363 vnlru_recalc();
364 mtx_unlock(&vnode_list_mtx);
365 /*
366 * XXX There is no protection against multiple threads changing
367 * desiredvnodes at the same time. Locking above only helps vnlru and
368 * getnewvnode.
369 */
370 vfs_hash_changesize(desiredvnodes);
371 cache_changesize(desiredvnodes);
372 return (0);
373 }
374
375 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
376 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
377 "LU", "Target for maximum number of vnodes (legacy)");
378 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, limit,
379 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
380 "LU", "Target for maximum number of vnodes");
381
382 static int
sysctl_freevnodes(SYSCTL_HANDLER_ARGS)383 sysctl_freevnodes(SYSCTL_HANDLER_ARGS)
384 {
385 u_long rfreevnodes;
386
387 rfreevnodes = vnlru_read_freevnodes();
388 return (sysctl_handle_long(oidp, &rfreevnodes, 0, req));
389 }
390
391 SYSCTL_PROC(_vfs, OID_AUTO, freevnodes,
392 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
393 "LU", "Number of \"free\" vnodes (legacy)");
394 SYSCTL_PROC(_vfs_vnode_stats, OID_AUTO, free,
395 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
396 "LU", "Number of \"free\" vnodes");
397
398 static int
sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)399 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)
400 {
401 u_long val;
402 int error;
403
404 val = wantfreevnodes;
405 error = sysctl_handle_long(oidp, &val, 0, req);
406 if (error != 0 || req->newptr == NULL)
407 return (error);
408
409 if (val == wantfreevnodes)
410 return (0);
411 mtx_lock(&vnode_list_mtx);
412 wantfreevnodes = val;
413 vnlru_recalc();
414 mtx_unlock(&vnode_list_mtx);
415 return (0);
416 }
417
418 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes,
419 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
420 "LU", "Target for minimum number of \"free\" vnodes (legacy)");
421 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, wantfree,
422 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
423 "LU", "Target for minimum number of \"free\" vnodes");
424
425 static int vnlru_nowhere;
426 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, failed_runs, CTLFLAG_RD | CTLFLAG_STATS,
427 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
428
429 static int
sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)430 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
431 {
432 struct vnode *vp;
433 struct nameidata nd;
434 char *buf;
435 unsigned long ndflags;
436 int error;
437
438 if (req->newptr == NULL)
439 return (EINVAL);
440 if (req->newlen >= PATH_MAX)
441 return (E2BIG);
442
443 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK);
444 error = SYSCTL_IN(req, buf, req->newlen);
445 if (error != 0)
446 goto out;
447
448 buf[req->newlen] = '\0';
449
450 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1;
451 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf);
452 if ((error = namei(&nd)) != 0)
453 goto out;
454 vp = nd.ni_vp;
455
456 if (VN_IS_DOOMED(vp)) {
457 /*
458 * This vnode is being recycled. Return != 0 to let the caller
459 * know that the sysctl had no effect. Return EAGAIN because a
460 * subsequent call will likely succeed (since namei will create
461 * a new vnode if necessary)
462 */
463 error = EAGAIN;
464 goto putvnode;
465 }
466
467 vgone(vp);
468 putvnode:
469 vput(vp);
470 NDFREE_PNBUF(&nd);
471 out:
472 free(buf, M_TEMP);
473 return (error);
474 }
475
476 static int
sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)477 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)
478 {
479 struct thread *td = curthread;
480 struct vnode *vp;
481 struct file *fp;
482 int error;
483 int fd;
484
485 if (req->newptr == NULL)
486 return (EBADF);
487
488 error = sysctl_handle_int(oidp, &fd, 0, req);
489 if (error != 0)
490 return (error);
491 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp);
492 if (error != 0)
493 return (error);
494 vp = fp->f_vnode;
495
496 error = vn_lock(vp, LK_EXCLUSIVE);
497 if (error != 0)
498 goto drop;
499
500 vgone(vp);
501 VOP_UNLOCK(vp);
502 drop:
503 fdrop(fp, td);
504 return (error);
505 }
506
507 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
508 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
509 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
510 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode,
511 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
512 sysctl_ftry_reclaim_vnode, "I",
513 "Try to reclaim a vnode by its file descriptor");
514
515 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
516 #define vnsz2log 8
517 #ifndef DEBUG_LOCKS
518 _Static_assert(sizeof(struct vnode) >= 1UL << vnsz2log &&
519 sizeof(struct vnode) < 1UL << (vnsz2log + 1),
520 "vnsz2log needs to be updated");
521 #endif
522
523 /*
524 * Support for the bufobj clean & dirty pctrie.
525 */
526 static void *
buf_trie_alloc(struct pctrie * ptree)527 buf_trie_alloc(struct pctrie *ptree)
528 {
529 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT));
530 }
531
532 static void
buf_trie_free(struct pctrie * ptree,void * node)533 buf_trie_free(struct pctrie *ptree, void *node)
534 {
535 uma_zfree_smr(buf_trie_zone, node);
536 }
537 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free,
538 buf_trie_smr);
539
540 /*
541 * Lookup the next element greater than or equal to lblkno, accounting for the
542 * fact that, for pctries, negative values are greater than nonnegative ones.
543 */
544 static struct buf *
buf_lookup_ge(struct bufv * bv,daddr_t lblkno)545 buf_lookup_ge(struct bufv *bv, daddr_t lblkno)
546 {
547 struct buf *bp;
548
549 bp = BUF_PCTRIE_LOOKUP_GE(&bv->bv_root, lblkno);
550 if (bp == NULL && lblkno < 0)
551 bp = BUF_PCTRIE_LOOKUP_GE(&bv->bv_root, 0);
552 if (bp != NULL && bp->b_lblkno < lblkno)
553 bp = NULL;
554 return (bp);
555 }
556
557 /*
558 * Insert bp, and find the next element smaller than bp, accounting for the fact
559 * that, for pctries, negative values are greater than nonnegative ones.
560 */
561 static int
buf_insert_lookup_le(struct bufv * bv,struct buf * bp,struct buf ** n)562 buf_insert_lookup_le(struct bufv *bv, struct buf *bp, struct buf **n)
563 {
564 int error;
565
566 error = BUF_PCTRIE_INSERT_LOOKUP_LE(&bv->bv_root, bp, n);
567 if (error != EEXIST) {
568 if (*n == NULL && bp->b_lblkno >= 0)
569 *n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, ~0L);
570 if (*n != NULL && (*n)->b_lblkno >= bp->b_lblkno)
571 *n = NULL;
572 }
573 return (error);
574 }
575
576 /*
577 * Initialize the vnode management data structures.
578 *
579 * Reevaluate the following cap on the number of vnodes after the physical
580 * memory size exceeds 512GB. In the limit, as the physical memory size
581 * grows, the ratio of the memory size in KB to vnodes approaches 64:1.
582 */
583 #ifndef MAXVNODES_MAX
584 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */
585 #endif
586
587 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
588
589 static struct vnode *
vn_alloc_marker(struct mount * mp)590 vn_alloc_marker(struct mount *mp)
591 {
592 struct vnode *vp;
593
594 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
595 vp->v_type = VMARKER;
596 vp->v_mount = mp;
597
598 return (vp);
599 }
600
601 static void
vn_free_marker(struct vnode * vp)602 vn_free_marker(struct vnode *vp)
603 {
604
605 MPASS(vp->v_type == VMARKER);
606 free(vp, M_VNODE_MARKER);
607 }
608
609 #ifdef KASAN
610 static int
vnode_ctor(void * mem,int size,void * arg __unused,int flags __unused)611 vnode_ctor(void *mem, int size, void *arg __unused, int flags __unused)
612 {
613 kasan_mark(mem, size, roundup2(size, UMA_ALIGN_PTR + 1), 0);
614 return (0);
615 }
616
617 static void
vnode_dtor(void * mem,int size,void * arg __unused)618 vnode_dtor(void *mem, int size, void *arg __unused)
619 {
620 size_t end1, end2, off1, off2;
621
622 _Static_assert(offsetof(struct vnode, v_vnodelist) <
623 offsetof(struct vnode, v_dbatchcpu),
624 "KASAN marks require updating");
625
626 off1 = offsetof(struct vnode, v_vnodelist);
627 off2 = offsetof(struct vnode, v_dbatchcpu);
628 end1 = off1 + sizeof(((struct vnode *)NULL)->v_vnodelist);
629 end2 = off2 + sizeof(((struct vnode *)NULL)->v_dbatchcpu);
630
631 /*
632 * Access to the v_vnodelist and v_dbatchcpu fields are permitted even
633 * after the vnode has been freed. Try to get some KASAN coverage by
634 * marking everything except those two fields as invalid. Because
635 * KASAN's tracking is not byte-granular, any preceding fields sharing
636 * the same 8-byte aligned word must also be marked valid.
637 */
638
639 /* Handle the area from the start until v_vnodelist... */
640 off1 = rounddown2(off1, KASAN_SHADOW_SCALE);
641 kasan_mark(mem, off1, off1, KASAN_UMA_FREED);
642
643 /* ... then the area between v_vnodelist and v_dbatchcpu ... */
644 off1 = roundup2(end1, KASAN_SHADOW_SCALE);
645 off2 = rounddown2(off2, KASAN_SHADOW_SCALE);
646 if (off2 > off1)
647 kasan_mark((void *)((char *)mem + off1), off2 - off1,
648 off2 - off1, KASAN_UMA_FREED);
649
650 /* ... and finally the area from v_dbatchcpu to the end. */
651 off2 = roundup2(end2, KASAN_SHADOW_SCALE);
652 kasan_mark((void *)((char *)mem + off2), size - off2, size - off2,
653 KASAN_UMA_FREED);
654 }
655 #endif /* KASAN */
656
657 /*
658 * Initialize a vnode as it first enters the zone.
659 */
660 static int
vnode_init(void * mem,int size,int flags)661 vnode_init(void *mem, int size, int flags)
662 {
663 struct vnode *vp;
664
665 vp = mem;
666 bzero(vp, size);
667 /*
668 * Setup locks.
669 */
670 vp->v_vnlock = &vp->v_lock;
671 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
672 /*
673 * By default, don't allow shared locks unless filesystems opt-in.
674 */
675 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
676 LK_NOSHARE | LK_IS_VNODE);
677 /*
678 * Initialize bufobj.
679 */
680 bufobj_init(&vp->v_bufobj, vp);
681 /*
682 * Initialize namecache.
683 */
684 cache_vnode_init(vp);
685 /*
686 * Initialize rangelocks.
687 */
688 rangelock_init(&vp->v_rl);
689
690 vp->v_dbatchcpu = NOCPU;
691
692 vp->v_state = VSTATE_DEAD;
693
694 /*
695 * Check vhold_recycle_free for an explanation.
696 */
697 vp->v_holdcnt = VHOLD_NO_SMR;
698 vp->v_type = VNON;
699 mtx_lock(&vnode_list_mtx);
700 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist);
701 mtx_unlock(&vnode_list_mtx);
702 return (0);
703 }
704
705 /*
706 * Free a vnode when it is cleared from the zone.
707 */
708 static void
vnode_fini(void * mem,int size)709 vnode_fini(void *mem, int size)
710 {
711 struct vnode *vp;
712 struct bufobj *bo;
713
714 vp = mem;
715 vdbatch_dequeue(vp);
716 mtx_lock(&vnode_list_mtx);
717 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
718 mtx_unlock(&vnode_list_mtx);
719 rangelock_destroy(&vp->v_rl);
720 lockdestroy(vp->v_vnlock);
721 mtx_destroy(&vp->v_interlock);
722 bo = &vp->v_bufobj;
723 rw_destroy(BO_LOCKPTR(bo));
724
725 kasan_mark(mem, size, size, 0);
726 }
727
728 /*
729 * Provide the size of NFS nclnode and NFS fh for calculation of the
730 * vnode memory consumption. The size is specified directly to
731 * eliminate dependency on NFS-private header.
732 *
733 * Other filesystems may use bigger or smaller (like UFS and ZFS)
734 * private inode data, but the NFS-based estimation is ample enough.
735 * Still, we care about differences in the size between 64- and 32-bit
736 * platforms.
737 *
738 * Namecache structure size is heuristically
739 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
740 */
741 #ifdef _LP64
742 #define NFS_NCLNODE_SZ (528 + 64)
743 #define NC_SZ 148
744 #else
745 #define NFS_NCLNODE_SZ (360 + 32)
746 #define NC_SZ 92
747 #endif
748
749 static void
vntblinit(void * dummy __unused)750 vntblinit(void *dummy __unused)
751 {
752 struct vdbatch *vd;
753 uma_ctor ctor;
754 uma_dtor dtor;
755 int cpu, physvnodes, virtvnodes;
756
757 /*
758 * Desiredvnodes is a function of the physical memory size and the
759 * kernel's heap size. Generally speaking, it scales with the
760 * physical memory size. The ratio of desiredvnodes to the physical
761 * memory size is 1:16 until desiredvnodes exceeds 98,304.
762 * Thereafter, the
763 * marginal ratio of desiredvnodes to the physical memory size is
764 * 1:64. However, desiredvnodes is limited by the kernel's heap
765 * size. The memory required by desiredvnodes vnodes and vm objects
766 * must not exceed 1/10th of the kernel's heap size.
767 */
768 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
769 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
770 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
771 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
772 desiredvnodes = min(physvnodes, virtvnodes);
773 if (desiredvnodes > MAXVNODES_MAX) {
774 if (bootverbose)
775 printf("Reducing kern.maxvnodes %lu -> %lu\n",
776 desiredvnodes, MAXVNODES_MAX);
777 desiredvnodes = MAXVNODES_MAX;
778 }
779 wantfreevnodes = desiredvnodes / 4;
780 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
781 TAILQ_INIT(&vnode_list);
782 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF);
783 /*
784 * The lock is taken to appease WITNESS.
785 */
786 mtx_lock(&vnode_list_mtx);
787 vnlru_recalc();
788 mtx_unlock(&vnode_list_mtx);
789 vnode_list_free_marker = vn_alloc_marker(NULL);
790 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist);
791 vnode_list_reclaim_marker = vn_alloc_marker(NULL);
792 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist);
793
794 #ifdef KASAN
795 ctor = vnode_ctor;
796 dtor = vnode_dtor;
797 #else
798 ctor = NULL;
799 dtor = NULL;
800 #endif
801 vnode_zone = uma_zcreate("VNODE", sizeof(struct vnode), ctor, dtor,
802 vnode_init, vnode_fini, UMA_ALIGN_PTR, UMA_ZONE_NOKASAN);
803 uma_zone_set_smr(vnode_zone, vfs_smr);
804
805 /*
806 * Preallocate enough nodes to support one-per buf so that
807 * we can not fail an insert. reassignbuf() callers can not
808 * tolerate the insertion failure.
809 */
810 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
811 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
812 UMA_ZONE_NOFREE | UMA_ZONE_SMR);
813 buf_trie_smr = uma_zone_get_smr(buf_trie_zone);
814 uma_prealloc(buf_trie_zone, nbuf);
815
816 vnodes_created = counter_u64_alloc(M_WAITOK);
817 direct_recycles_free_count = counter_u64_alloc(M_WAITOK);
818 vnode_skipped_requeues = counter_u64_alloc(M_WAITOK);
819
820 /*
821 * Initialize the filesystem syncer.
822 */
823 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
824 &syncer_mask);
825 syncer_maxdelay = syncer_mask + 1;
826 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
827 cv_init(&sync_wakeup, "syncer");
828
829 CPU_FOREACH(cpu) {
830 vd = DPCPU_ID_PTR((cpu), vd);
831 bzero(vd, sizeof(*vd));
832 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF);
833 }
834 }
835 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
836
837 /*
838 * Mark a mount point as busy. Used to synchronize access and to delay
839 * unmounting. Eventually, mountlist_mtx is not released on failure.
840 *
841 * vfs_busy() is a custom lock, it can block the caller.
842 * vfs_busy() only sleeps if the unmount is active on the mount point.
843 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
844 * vnode belonging to mp.
845 *
846 * Lookup uses vfs_busy() to traverse mount points.
847 * root fs var fs
848 * / vnode lock A / vnode lock (/var) D
849 * /var vnode lock B /log vnode lock(/var/log) E
850 * vfs_busy lock C vfs_busy lock F
851 *
852 * Within each file system, the lock order is C->A->B and F->D->E.
853 *
854 * When traversing across mounts, the system follows that lock order:
855 *
856 * C->A->B
857 * |
858 * +->F->D->E
859 *
860 * The lookup() process for namei("/var") illustrates the process:
861 * 1. VOP_LOOKUP() obtains B while A is held
862 * 2. vfs_busy() obtains a shared lock on F while A and B are held
863 * 3. vput() releases lock on B
864 * 4. vput() releases lock on A
865 * 5. VFS_ROOT() obtains lock on D while shared lock on F is held
866 * 6. vfs_unbusy() releases shared lock on F
867 * 7. vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
868 * Attempt to lock A (instead of vp_crossmp) while D is held would
869 * violate the global order, causing deadlocks.
870 *
871 * dounmount() locks B while F is drained. Note that for stacked
872 * filesystems, D and B in the example above may be the same lock,
873 * which introdues potential lock order reversal deadlock between
874 * dounmount() and step 5 above. These filesystems may avoid the LOR
875 * by setting VV_CROSSLOCK on the covered vnode so that lock B will
876 * remain held until after step 5.
877 */
878 int
vfs_busy(struct mount * mp,int flags)879 vfs_busy(struct mount *mp, int flags)
880 {
881 struct mount_pcpu *mpcpu;
882
883 MPASS((flags & ~MBF_MASK) == 0);
884 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
885
886 if (vfs_op_thread_enter(mp, mpcpu)) {
887 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
888 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0);
889 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0);
890 vfs_mp_count_add_pcpu(mpcpu, ref, 1);
891 vfs_mp_count_add_pcpu(mpcpu, lockref, 1);
892 vfs_op_thread_exit(mp, mpcpu);
893 if (flags & MBF_MNTLSTLOCK)
894 mtx_unlock(&mountlist_mtx);
895 return (0);
896 }
897
898 MNT_ILOCK(mp);
899 vfs_assert_mount_counters(mp);
900 MNT_REF(mp);
901 /*
902 * If mount point is currently being unmounted, sleep until the
903 * mount point fate is decided. If thread doing the unmounting fails,
904 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
905 * that this mount point has survived the unmount attempt and vfs_busy
906 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
907 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
908 * about to be really destroyed. vfs_busy needs to release its
909 * reference on the mount point in this case and return with ENOENT,
910 * telling the caller the mount it tried to busy is no longer valid.
911 */
912 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
913 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers),
914 ("%s: non-empty upper mount list with pending unmount",
915 __func__));
916 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
917 MNT_REL(mp);
918 MNT_IUNLOCK(mp);
919 CTR1(KTR_VFS, "%s: failed busying before sleeping",
920 __func__);
921 return (ENOENT);
922 }
923 if (flags & MBF_MNTLSTLOCK)
924 mtx_unlock(&mountlist_mtx);
925 mp->mnt_kern_flag |= MNTK_MWAIT;
926 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
927 if (flags & MBF_MNTLSTLOCK)
928 mtx_lock(&mountlist_mtx);
929 MNT_ILOCK(mp);
930 }
931 if (flags & MBF_MNTLSTLOCK)
932 mtx_unlock(&mountlist_mtx);
933 mp->mnt_lockref++;
934 MNT_IUNLOCK(mp);
935 return (0);
936 }
937
938 /*
939 * Free a busy filesystem.
940 */
941 void
vfs_unbusy(struct mount * mp)942 vfs_unbusy(struct mount *mp)
943 {
944 struct mount_pcpu *mpcpu;
945 int c;
946
947 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
948
949 if (vfs_op_thread_enter(mp, mpcpu)) {
950 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
951 vfs_mp_count_sub_pcpu(mpcpu, lockref, 1);
952 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
953 vfs_op_thread_exit(mp, mpcpu);
954 return;
955 }
956
957 MNT_ILOCK(mp);
958 vfs_assert_mount_counters(mp);
959 MNT_REL(mp);
960 c = --mp->mnt_lockref;
961 if (mp->mnt_vfs_ops == 0) {
962 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
963 MNT_IUNLOCK(mp);
964 return;
965 }
966 if (c < 0)
967 vfs_dump_mount_counters(mp);
968 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
969 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
970 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
971 mp->mnt_kern_flag &= ~MNTK_DRAINING;
972 wakeup(&mp->mnt_lockref);
973 }
974 MNT_IUNLOCK(mp);
975 }
976
977 /*
978 * Lookup a mount point by filesystem identifier.
979 */
980 struct mount *
vfs_getvfs(fsid_t * fsid)981 vfs_getvfs(fsid_t *fsid)
982 {
983 struct mount *mp;
984
985 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
986 mtx_lock(&mountlist_mtx);
987 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
988 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
989 vfs_ref(mp);
990 mtx_unlock(&mountlist_mtx);
991 return (mp);
992 }
993 }
994 mtx_unlock(&mountlist_mtx);
995 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
996 return ((struct mount *) 0);
997 }
998
999 /*
1000 * Lookup a mount point by filesystem identifier, busying it before
1001 * returning.
1002 *
1003 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
1004 * cache for popular filesystem identifiers. The cache is lockess, using
1005 * the fact that struct mount's are never freed. In worst case we may
1006 * get pointer to unmounted or even different filesystem, so we have to
1007 * check what we got, and go slow way if so.
1008 */
1009 struct mount *
vfs_busyfs(fsid_t * fsid)1010 vfs_busyfs(fsid_t *fsid)
1011 {
1012 #define FSID_CACHE_SIZE 256
1013 typedef struct mount * volatile vmp_t;
1014 static vmp_t cache[FSID_CACHE_SIZE];
1015 struct mount *mp;
1016 int error;
1017 uint32_t hash;
1018
1019 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
1020 hash = fsid->val[0] ^ fsid->val[1];
1021 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
1022 mp = cache[hash];
1023 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0)
1024 goto slow;
1025 if (vfs_busy(mp, 0) != 0) {
1026 cache[hash] = NULL;
1027 goto slow;
1028 }
1029 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0)
1030 return (mp);
1031 else
1032 vfs_unbusy(mp);
1033
1034 slow:
1035 mtx_lock(&mountlist_mtx);
1036 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
1037 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
1038 error = vfs_busy(mp, MBF_MNTLSTLOCK);
1039 if (error) {
1040 cache[hash] = NULL;
1041 mtx_unlock(&mountlist_mtx);
1042 return (NULL);
1043 }
1044 cache[hash] = mp;
1045 return (mp);
1046 }
1047 }
1048 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
1049 mtx_unlock(&mountlist_mtx);
1050 return ((struct mount *) 0);
1051 }
1052
1053 /*
1054 * Check if a user can access privileged mount options.
1055 */
1056 int
vfs_suser(struct mount * mp,struct thread * td)1057 vfs_suser(struct mount *mp, struct thread *td)
1058 {
1059 int error;
1060
1061 if (jailed(td->td_ucred)) {
1062 /*
1063 * If the jail of the calling thread lacks permission for
1064 * this type of file system, deny immediately.
1065 */
1066 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag))
1067 return (EPERM);
1068
1069 /*
1070 * If the file system was mounted outside the jail of the
1071 * calling thread, deny immediately.
1072 */
1073 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
1074 return (EPERM);
1075 }
1076
1077 /*
1078 * If file system supports delegated administration, we don't check
1079 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
1080 * by the file system itself.
1081 * If this is not the user that did original mount, we check for
1082 * the PRIV_VFS_MOUNT_OWNER privilege.
1083 */
1084 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
1085 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
1086 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
1087 return (error);
1088 }
1089 return (0);
1090 }
1091
1092 /*
1093 * Get a new unique fsid. Try to make its val[0] unique, since this value
1094 * will be used to create fake device numbers for stat(). Also try (but
1095 * not so hard) make its val[0] unique mod 2^16, since some emulators only
1096 * support 16-bit device numbers. We end up with unique val[0]'s for the
1097 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
1098 *
1099 * Keep in mind that several mounts may be running in parallel. Starting
1100 * the search one past where the previous search terminated is both a
1101 * micro-optimization and a defense against returning the same fsid to
1102 * different mounts.
1103 */
1104 void
vfs_getnewfsid(struct mount * mp)1105 vfs_getnewfsid(struct mount *mp)
1106 {
1107 static uint16_t mntid_base;
1108 struct mount *nmp;
1109 fsid_t tfsid;
1110 int mtype;
1111
1112 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
1113 mtx_lock(&mntid_mtx);
1114 mtype = mp->mnt_vfc->vfc_typenum;
1115 tfsid.val[1] = mtype;
1116 mtype = (mtype & 0xFF) << 24;
1117 for (;;) {
1118 tfsid.val[0] = makedev(255,
1119 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
1120 mntid_base++;
1121 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
1122 break;
1123 vfs_rel(nmp);
1124 }
1125 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
1126 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
1127 mtx_unlock(&mntid_mtx);
1128 }
1129
1130 /*
1131 * Knob to control the precision of file timestamps:
1132 *
1133 * 0 = seconds only; nanoseconds zeroed.
1134 * 1 = seconds and nanoseconds, accurate within 1/HZ.
1135 * 2 = seconds and nanoseconds, truncated to microseconds.
1136 * >=3 = seconds and nanoseconds, maximum precision.
1137 */
1138 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
1139
1140 static int timestamp_precision = TSP_USEC;
1141 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
1142 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
1143 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, "
1144 "3+: sec + ns (max. precision))");
1145
1146 /*
1147 * Get a current timestamp.
1148 */
1149 void
vfs_timestamp(struct timespec * tsp)1150 vfs_timestamp(struct timespec *tsp)
1151 {
1152 struct timeval tv;
1153
1154 switch (timestamp_precision) {
1155 case TSP_SEC:
1156 tsp->tv_sec = time_second;
1157 tsp->tv_nsec = 0;
1158 break;
1159 case TSP_HZ:
1160 getnanotime(tsp);
1161 break;
1162 case TSP_USEC:
1163 microtime(&tv);
1164 TIMEVAL_TO_TIMESPEC(&tv, tsp);
1165 break;
1166 case TSP_NSEC:
1167 default:
1168 nanotime(tsp);
1169 break;
1170 }
1171 }
1172
1173 /*
1174 * Set vnode attributes to VNOVAL
1175 */
1176 void
vattr_null(struct vattr * vap)1177 vattr_null(struct vattr *vap)
1178 {
1179
1180 vap->va_type = VNON;
1181 vap->va_size = VNOVAL;
1182 vap->va_bytes = VNOVAL;
1183 vap->va_mode = VNOVAL;
1184 vap->va_nlink = VNOVAL;
1185 vap->va_uid = VNOVAL;
1186 vap->va_gid = VNOVAL;
1187 vap->va_fsid = VNOVAL;
1188 vap->va_fileid = VNOVAL;
1189 vap->va_blocksize = VNOVAL;
1190 vap->va_rdev = VNOVAL;
1191 vap->va_atime.tv_sec = VNOVAL;
1192 vap->va_atime.tv_nsec = VNOVAL;
1193 vap->va_mtime.tv_sec = VNOVAL;
1194 vap->va_mtime.tv_nsec = VNOVAL;
1195 vap->va_ctime.tv_sec = VNOVAL;
1196 vap->va_ctime.tv_nsec = VNOVAL;
1197 vap->va_birthtime.tv_sec = VNOVAL;
1198 vap->va_birthtime.tv_nsec = VNOVAL;
1199 vap->va_flags = VNOVAL;
1200 vap->va_gen = VNOVAL;
1201 vap->va_vaflags = 0;
1202 }
1203
1204 /*
1205 * Try to reduce the total number of vnodes.
1206 *
1207 * This routine (and its user) are buggy in at least the following ways:
1208 * - all parameters were picked years ago when RAM sizes were significantly
1209 * smaller
1210 * - it can pick vnodes based on pages used by the vm object, but filesystems
1211 * like ZFS don't use it making the pick broken
1212 * - since ZFS has its own aging policy it gets partially combated by this one
1213 * - a dedicated method should be provided for filesystems to let them decide
1214 * whether the vnode should be recycled
1215 *
1216 * This routine is called when we have too many vnodes. It attempts
1217 * to free <count> vnodes and will potentially free vnodes that still
1218 * have VM backing store (VM backing store is typically the cause
1219 * of a vnode blowout so we want to do this). Therefore, this operation
1220 * is not considered cheap.
1221 *
1222 * A number of conditions may prevent a vnode from being reclaimed.
1223 * the buffer cache may have references on the vnode, a directory
1224 * vnode may still have references due to the namei cache representing
1225 * underlying files, or the vnode may be in active use. It is not
1226 * desirable to reuse such vnodes. These conditions may cause the
1227 * number of vnodes to reach some minimum value regardless of what
1228 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
1229 *
1230 * @param reclaim_nc_src Only reclaim directories with outgoing namecache
1231 * entries if this argument is strue
1232 * @param trigger Only reclaim vnodes with fewer than this many resident
1233 * pages.
1234 * @param target How many vnodes to reclaim.
1235 * @return The number of vnodes that were reclaimed.
1236 */
1237 static int
vlrureclaim(bool reclaim_nc_src,int trigger,u_long target)1238 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target)
1239 {
1240 struct vnode *vp, *mvp;
1241 struct mount *mp;
1242 struct vm_object *object;
1243 u_long done;
1244 bool retried;
1245
1246 mtx_assert(&vnode_list_mtx, MA_OWNED);
1247
1248 retried = false;
1249 done = 0;
1250
1251 mvp = vnode_list_reclaim_marker;
1252 restart:
1253 vp = mvp;
1254 while (done < target) {
1255 vp = TAILQ_NEXT(vp, v_vnodelist);
1256 if (__predict_false(vp == NULL))
1257 break;
1258
1259 if (__predict_false(vp->v_type == VMARKER))
1260 continue;
1261
1262 /*
1263 * If it's been deconstructed already, it's still
1264 * referenced, or it exceeds the trigger, skip it.
1265 * Also skip free vnodes. We are trying to make space
1266 * for more free vnodes, not reduce their count.
1267 */
1268 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 ||
1269 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)))
1270 goto next_iter;
1271
1272 if (vp->v_type == VBAD || vp->v_type == VNON)
1273 goto next_iter;
1274
1275 object = atomic_load_ptr(&vp->v_object);
1276 if (object == NULL || object->resident_page_count > trigger) {
1277 goto next_iter;
1278 }
1279
1280 /*
1281 * Handle races against vnode allocation. Filesystems lock the
1282 * vnode some time after it gets returned from getnewvnode,
1283 * despite type and hold count being manipulated earlier.
1284 * Resorting to checking v_mount restores guarantees present
1285 * before the global list was reworked to contain all vnodes.
1286 */
1287 if (!VI_TRYLOCK(vp))
1288 goto next_iter;
1289 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1290 VI_UNLOCK(vp);
1291 goto next_iter;
1292 }
1293 if (vp->v_mount == NULL) {
1294 VI_UNLOCK(vp);
1295 goto next_iter;
1296 }
1297 vholdl(vp);
1298 VI_UNLOCK(vp);
1299 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1300 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1301 mtx_unlock(&vnode_list_mtx);
1302
1303 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1304 vdrop_recycle(vp);
1305 goto next_iter_unlocked;
1306 }
1307 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) {
1308 vdrop_recycle(vp);
1309 vn_finished_write(mp);
1310 goto next_iter_unlocked;
1311 }
1312
1313 VI_LOCK(vp);
1314 if (vp->v_usecount > 0 ||
1315 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1316 (vp->v_object != NULL && vp->v_object->handle == vp &&
1317 vp->v_object->resident_page_count > trigger)) {
1318 VOP_UNLOCK(vp);
1319 vdropl_recycle(vp);
1320 vn_finished_write(mp);
1321 goto next_iter_unlocked;
1322 }
1323 recycles_count++;
1324 vgonel(vp);
1325 VOP_UNLOCK(vp);
1326 vdropl_recycle(vp);
1327 vn_finished_write(mp);
1328 done++;
1329 next_iter_unlocked:
1330 maybe_yield();
1331 mtx_lock(&vnode_list_mtx);
1332 goto restart;
1333 next_iter:
1334 MPASS(vp->v_type != VMARKER);
1335 if (!should_yield())
1336 continue;
1337 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1338 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1339 mtx_unlock(&vnode_list_mtx);
1340 kern_yield(PRI_USER);
1341 mtx_lock(&vnode_list_mtx);
1342 goto restart;
1343 }
1344 if (done == 0 && !retried) {
1345 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1346 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1347 retried = true;
1348 goto restart;
1349 }
1350 return (done);
1351 }
1352
1353 static int max_free_per_call = 10000;
1354 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_free_per_call, 0,
1355 "limit on vnode free requests per call to the vnlru_free routine (legacy)");
1356 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, max_free_per_call, CTLFLAG_RW,
1357 &max_free_per_call, 0,
1358 "limit on vnode free requests per call to the vnlru_free routine");
1359
1360 /*
1361 * Attempt to recycle requested amount of free vnodes.
1362 */
1363 static int
vnlru_free_impl(int count,struct vfsops * mnt_op,struct vnode * mvp,bool isvnlru)1364 vnlru_free_impl(int count, struct vfsops *mnt_op, struct vnode *mvp, bool isvnlru)
1365 {
1366 struct vnode *vp;
1367 struct mount *mp;
1368 int ocount;
1369 bool retried;
1370
1371 mtx_assert(&vnode_list_mtx, MA_OWNED);
1372 if (count > max_free_per_call)
1373 count = max_free_per_call;
1374 if (count == 0) {
1375 mtx_unlock(&vnode_list_mtx);
1376 return (0);
1377 }
1378 ocount = count;
1379 retried = false;
1380 vp = mvp;
1381 for (;;) {
1382 vp = TAILQ_NEXT(vp, v_vnodelist);
1383 if (__predict_false(vp == NULL)) {
1384 /*
1385 * The free vnode marker can be past eligible vnodes:
1386 * 1. if vdbatch_process trylock failed
1387 * 2. if vtryrecycle failed
1388 *
1389 * If so, start the scan from scratch.
1390 */
1391 if (!retried && vnlru_read_freevnodes() > 0) {
1392 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1393 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1394 vp = mvp;
1395 retried = true;
1396 continue;
1397 }
1398
1399 /*
1400 * Give up
1401 */
1402 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1403 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist);
1404 mtx_unlock(&vnode_list_mtx);
1405 break;
1406 }
1407 if (__predict_false(vp->v_type == VMARKER))
1408 continue;
1409 if (vp->v_holdcnt > 0)
1410 continue;
1411 /*
1412 * Don't recycle if our vnode is from different type
1413 * of mount point. Note that mp is type-safe, the
1414 * check does not reach unmapped address even if
1415 * vnode is reclaimed.
1416 */
1417 if (mnt_op != NULL && (mp = vp->v_mount) != NULL &&
1418 mp->mnt_op != mnt_op) {
1419 continue;
1420 }
1421 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1422 continue;
1423 }
1424 if (!vhold_recycle_free(vp))
1425 continue;
1426 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1427 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1428 mtx_unlock(&vnode_list_mtx);
1429 /*
1430 * FIXME: ignores the return value, meaning it may be nothing
1431 * got recycled but it claims otherwise to the caller.
1432 *
1433 * Originally the value started being ignored in 2005 with
1434 * 114a1006a8204aa156e1f9ad6476cdff89cada7f .
1435 *
1436 * Respecting the value can run into significant stalls if most
1437 * vnodes belong to one file system and it has writes
1438 * suspended. In presence of many threads and millions of
1439 * vnodes they keep contending on the vnode_list_mtx lock only
1440 * to find vnodes they can't recycle.
1441 *
1442 * The solution would be to pre-check if the vnode is likely to
1443 * be recycle-able, but it needs to happen with the
1444 * vnode_list_mtx lock held. This runs into a problem where
1445 * VOP_GETWRITEMOUNT (currently needed to find out about if
1446 * writes are frozen) can take locks which LOR against it.
1447 *
1448 * Check nullfs for one example (null_getwritemount).
1449 */
1450 vtryrecycle(vp, isvnlru);
1451 count--;
1452 if (count == 0) {
1453 break;
1454 }
1455 mtx_lock(&vnode_list_mtx);
1456 vp = mvp;
1457 }
1458 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1459 return (ocount - count);
1460 }
1461
1462 /*
1463 * XXX: returns without vnode_list_mtx locked!
1464 */
1465 static int
vnlru_free_locked_direct(int count)1466 vnlru_free_locked_direct(int count)
1467 {
1468 int ret;
1469
1470 mtx_assert(&vnode_list_mtx, MA_OWNED);
1471 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, false);
1472 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1473 return (ret);
1474 }
1475
1476 static int
vnlru_free_locked_vnlru(int count)1477 vnlru_free_locked_vnlru(int count)
1478 {
1479 int ret;
1480
1481 mtx_assert(&vnode_list_mtx, MA_OWNED);
1482 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, true);
1483 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1484 return (ret);
1485 }
1486
1487 static int
vnlru_free_vnlru(int count)1488 vnlru_free_vnlru(int count)
1489 {
1490
1491 mtx_lock(&vnode_list_mtx);
1492 return (vnlru_free_locked_vnlru(count));
1493 }
1494
1495 void
vnlru_free_vfsops(int count,struct vfsops * mnt_op,struct vnode * mvp)1496 vnlru_free_vfsops(int count, struct vfsops *mnt_op, struct vnode *mvp)
1497 {
1498
1499 MPASS(mnt_op != NULL);
1500 MPASS(mvp != NULL);
1501 VNPASS(mvp->v_type == VMARKER, mvp);
1502 mtx_lock(&vnode_list_mtx);
1503 vnlru_free_impl(count, mnt_op, mvp, true);
1504 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1505 }
1506
1507 struct vnode *
vnlru_alloc_marker(void)1508 vnlru_alloc_marker(void)
1509 {
1510 struct vnode *mvp;
1511
1512 mvp = vn_alloc_marker(NULL);
1513 mtx_lock(&vnode_list_mtx);
1514 TAILQ_INSERT_BEFORE(vnode_list_free_marker, mvp, v_vnodelist);
1515 mtx_unlock(&vnode_list_mtx);
1516 return (mvp);
1517 }
1518
1519 void
vnlru_free_marker(struct vnode * mvp)1520 vnlru_free_marker(struct vnode *mvp)
1521 {
1522 mtx_lock(&vnode_list_mtx);
1523 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1524 mtx_unlock(&vnode_list_mtx);
1525 vn_free_marker(mvp);
1526 }
1527
1528 static void
vnlru_recalc(void)1529 vnlru_recalc(void)
1530 {
1531
1532 mtx_assert(&vnode_list_mtx, MA_OWNED);
1533 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1534 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1535 vlowat = vhiwat / 2;
1536 }
1537
1538 /*
1539 * Attempt to recycle vnodes in a context that is always safe to block.
1540 * Calling vlrurecycle() from the bowels of filesystem code has some
1541 * interesting deadlock problems.
1542 */
1543 static struct proc *vnlruproc;
1544 static int vnlruproc_sig;
1545 static u_long vnlruproc_kicks;
1546
1547 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, kicks, CTLFLAG_RD, &vnlruproc_kicks, 0,
1548 "Number of times vnlru awakened due to vnode shortage");
1549
1550 #define VNLRU_COUNT_SLOP 100
1551
1552 /*
1553 * The main freevnodes counter is only updated when a counter local to CPU
1554 * diverges from 0 by more than VNLRU_FREEVNODES_SLOP. CPUs are conditionally
1555 * walked to compute a more accurate total.
1556 *
1557 * Note: the actual value at any given moment can still exceed slop, but it
1558 * should not be by significant margin in practice.
1559 */
1560 #define VNLRU_FREEVNODES_SLOP 126
1561
1562 static void __noinline
vfs_freevnodes_rollup(int8_t * lfreevnodes)1563 vfs_freevnodes_rollup(int8_t *lfreevnodes)
1564 {
1565
1566 atomic_add_long(&freevnodes, *lfreevnodes);
1567 *lfreevnodes = 0;
1568 critical_exit();
1569 }
1570
1571 static __inline void
vfs_freevnodes_inc(void)1572 vfs_freevnodes_inc(void)
1573 {
1574 int8_t *lfreevnodes;
1575
1576 critical_enter();
1577 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1578 (*lfreevnodes)++;
1579 if (__predict_false(*lfreevnodes == VNLRU_FREEVNODES_SLOP))
1580 vfs_freevnodes_rollup(lfreevnodes);
1581 else
1582 critical_exit();
1583 }
1584
1585 static __inline void
vfs_freevnodes_dec(void)1586 vfs_freevnodes_dec(void)
1587 {
1588 int8_t *lfreevnodes;
1589
1590 critical_enter();
1591 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1592 (*lfreevnodes)--;
1593 if (__predict_false(*lfreevnodes == -VNLRU_FREEVNODES_SLOP))
1594 vfs_freevnodes_rollup(lfreevnodes);
1595 else
1596 critical_exit();
1597 }
1598
1599 static u_long
vnlru_read_freevnodes(void)1600 vnlru_read_freevnodes(void)
1601 {
1602 long slop, rfreevnodes, rfreevnodes_old;
1603 int cpu;
1604
1605 rfreevnodes = atomic_load_long(&freevnodes);
1606 rfreevnodes_old = atomic_load_long(&freevnodes_old);
1607
1608 if (rfreevnodes > rfreevnodes_old)
1609 slop = rfreevnodes - rfreevnodes_old;
1610 else
1611 slop = rfreevnodes_old - rfreevnodes;
1612 if (slop < VNLRU_FREEVNODES_SLOP)
1613 return (rfreevnodes >= 0 ? rfreevnodes : 0);
1614 CPU_FOREACH(cpu) {
1615 rfreevnodes += cpuid_to_pcpu[cpu]->pc_vfs_freevnodes;
1616 }
1617 atomic_store_long(&freevnodes_old, rfreevnodes);
1618 return (freevnodes_old >= 0 ? freevnodes_old : 0);
1619 }
1620
1621 static bool
vnlru_under(u_long rnumvnodes,u_long limit)1622 vnlru_under(u_long rnumvnodes, u_long limit)
1623 {
1624 u_long rfreevnodes, space;
1625
1626 if (__predict_false(rnumvnodes > desiredvnodes))
1627 return (true);
1628
1629 space = desiredvnodes - rnumvnodes;
1630 if (space < limit) {
1631 rfreevnodes = vnlru_read_freevnodes();
1632 if (rfreevnodes > wantfreevnodes)
1633 space += rfreevnodes - wantfreevnodes;
1634 }
1635 return (space < limit);
1636 }
1637
1638 static void
vnlru_kick_locked(void)1639 vnlru_kick_locked(void)
1640 {
1641
1642 mtx_assert(&vnode_list_mtx, MA_OWNED);
1643 if (vnlruproc_sig == 0) {
1644 vnlruproc_sig = 1;
1645 vnlruproc_kicks++;
1646 wakeup(vnlruproc);
1647 }
1648 }
1649
1650 static void
vnlru_kick_cond(void)1651 vnlru_kick_cond(void)
1652 {
1653
1654 if (vnlru_read_freevnodes() > wantfreevnodes)
1655 return;
1656
1657 if (vnlruproc_sig)
1658 return;
1659 mtx_lock(&vnode_list_mtx);
1660 vnlru_kick_locked();
1661 mtx_unlock(&vnode_list_mtx);
1662 }
1663
1664 static void
vnlru_proc_sleep(void)1665 vnlru_proc_sleep(void)
1666 {
1667
1668 if (vnlruproc_sig) {
1669 vnlruproc_sig = 0;
1670 wakeup(&vnlruproc_sig);
1671 }
1672 msleep(vnlruproc, &vnode_list_mtx, PVFS|PDROP, "vlruwt", hz);
1673 }
1674
1675 /*
1676 * A lighter version of the machinery below.
1677 *
1678 * Tries to reach goals only by recycling free vnodes and does not invoke
1679 * uma_reclaim(UMA_RECLAIM_DRAIN).
1680 *
1681 * This works around pathological behavior in vnlru in presence of tons of free
1682 * vnodes, but without having to rewrite the machinery at this time. Said
1683 * behavior boils down to continuously trying to reclaim all kinds of vnodes
1684 * (cycling through all levels of "force") when the count is transiently above
1685 * limit. This happens a lot when all vnodes are used up and vn_alloc
1686 * speculatively increments the counter.
1687 *
1688 * Sample testcase: vnode limit 8388608, 20 separate directory trees each with
1689 * 1 million files in total and 20 find(1) processes stating them in parallel
1690 * (one per each tree).
1691 *
1692 * On a kernel with only stock machinery this needs anywhere between 60 and 120
1693 * seconds to execute (time varies *wildly* between runs). With the workaround
1694 * it consistently stays around 20 seconds [it got further down with later
1695 * changes].
1696 *
1697 * That is to say the entire thing needs a fundamental redesign (most notably
1698 * to accommodate faster recycling), the above only tries to get it ouf the way.
1699 *
1700 * Return values are:
1701 * -1 -- fallback to regular vnlru loop
1702 * 0 -- do nothing, go to sleep
1703 * >0 -- recycle this many vnodes
1704 */
1705 static long
vnlru_proc_light_pick(void)1706 vnlru_proc_light_pick(void)
1707 {
1708 u_long rnumvnodes, rfreevnodes;
1709
1710 if (vstir || vnlruproc_sig == 1)
1711 return (-1);
1712
1713 rnumvnodes = atomic_load_long(&numvnodes);
1714 rfreevnodes = vnlru_read_freevnodes();
1715
1716 /*
1717 * vnode limit might have changed and now we may be at a significant
1718 * excess. Bail if we can't sort it out with free vnodes.
1719 *
1720 * Due to atomic updates the count can legitimately go above
1721 * the limit for a short period, don't bother doing anything in
1722 * that case.
1723 */
1724 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP + 10) {
1725 if (rnumvnodes - rfreevnodes >= desiredvnodes ||
1726 rfreevnodes <= wantfreevnodes) {
1727 return (-1);
1728 }
1729
1730 return (rnumvnodes - desiredvnodes);
1731 }
1732
1733 /*
1734 * Don't try to reach wantfreevnodes target if there are too few vnodes
1735 * to begin with.
1736 */
1737 if (rnumvnodes < wantfreevnodes) {
1738 return (0);
1739 }
1740
1741 if (rfreevnodes < wantfreevnodes) {
1742 return (-1);
1743 }
1744
1745 return (0);
1746 }
1747
1748 static bool
vnlru_proc_light(void)1749 vnlru_proc_light(void)
1750 {
1751 long freecount;
1752
1753 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1754
1755 freecount = vnlru_proc_light_pick();
1756 if (freecount == -1)
1757 return (false);
1758
1759 if (freecount != 0) {
1760 vnlru_free_vnlru(freecount);
1761 }
1762
1763 mtx_lock(&vnode_list_mtx);
1764 vnlru_proc_sleep();
1765 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1766 return (true);
1767 }
1768
1769 static u_long uma_reclaim_calls;
1770 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, uma_reclaim_calls, CTLFLAG_RD | CTLFLAG_STATS,
1771 &uma_reclaim_calls, 0, "Number of calls to uma_reclaim");
1772
1773 static void
vnlru_proc(void)1774 vnlru_proc(void)
1775 {
1776 u_long rnumvnodes, rfreevnodes, target;
1777 unsigned long onumvnodes;
1778 int done, force, trigger, usevnodes;
1779 bool reclaim_nc_src, want_reread;
1780
1781 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1782 SHUTDOWN_PRI_FIRST);
1783
1784 force = 0;
1785 want_reread = false;
1786 for (;;) {
1787 kproc_suspend_check(vnlruproc);
1788
1789 if (force == 0 && vnlru_proc_light())
1790 continue;
1791
1792 mtx_lock(&vnode_list_mtx);
1793 rnumvnodes = atomic_load_long(&numvnodes);
1794
1795 if (want_reread) {
1796 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0;
1797 want_reread = false;
1798 }
1799
1800 /*
1801 * If numvnodes is too large (due to desiredvnodes being
1802 * adjusted using its sysctl, or emergency growth), first
1803 * try to reduce it by discarding free vnodes.
1804 */
1805 if (rnumvnodes > desiredvnodes + 10) {
1806 vnlru_free_locked_vnlru(rnumvnodes - desiredvnodes);
1807 mtx_lock(&vnode_list_mtx);
1808 rnumvnodes = atomic_load_long(&numvnodes);
1809 }
1810 /*
1811 * Sleep if the vnode cache is in a good state. This is
1812 * when it is not over-full and has space for about a 4%
1813 * or 9% expansion (by growing its size or inexcessively
1814 * reducing free vnode count). Otherwise, try to reclaim
1815 * space for a 10% expansion.
1816 */
1817 if (vstir && force == 0) {
1818 force = 1;
1819 vstir = false;
1820 }
1821 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) {
1822 vnlru_proc_sleep();
1823 continue;
1824 }
1825 rfreevnodes = vnlru_read_freevnodes();
1826
1827 onumvnodes = rnumvnodes;
1828 /*
1829 * Calculate parameters for recycling. These are the same
1830 * throughout the loop to give some semblance of fairness.
1831 * The trigger point is to avoid recycling vnodes with lots
1832 * of resident pages. We aren't trying to free memory; we
1833 * are trying to recycle or at least free vnodes.
1834 */
1835 if (rnumvnodes <= desiredvnodes)
1836 usevnodes = rnumvnodes - rfreevnodes;
1837 else
1838 usevnodes = rnumvnodes;
1839 if (usevnodes <= 0)
1840 usevnodes = 1;
1841 /*
1842 * The trigger value is chosen to give a conservatively
1843 * large value to ensure that it alone doesn't prevent
1844 * making progress. The value can easily be so large that
1845 * it is effectively infinite in some congested and
1846 * misconfigured cases, and this is necessary. Normally
1847 * it is about 8 to 100 (pages), which is quite large.
1848 */
1849 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1850 if (force < 2)
1851 trigger = vsmalltrigger;
1852 reclaim_nc_src = force >= 3;
1853 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1);
1854 target = target / 10 + 1;
1855 done = vlrureclaim(reclaim_nc_src, trigger, target);
1856 mtx_unlock(&vnode_list_mtx);
1857 /*
1858 * Total number of vnodes can transiently go slightly above the
1859 * limit (see vn_alloc_hard), no need to call uma_reclaim if
1860 * this happens.
1861 */
1862 if (onumvnodes + VNLRU_COUNT_SLOP + 1000 > desiredvnodes &&
1863 numvnodes <= desiredvnodes) {
1864 uma_reclaim_calls++;
1865 uma_reclaim(UMA_RECLAIM_DRAIN);
1866 }
1867 if (done == 0) {
1868 if (force == 0 || force == 1) {
1869 force = 2;
1870 continue;
1871 }
1872 if (force == 2) {
1873 force = 3;
1874 continue;
1875 }
1876 want_reread = true;
1877 force = 0;
1878 vnlru_nowhere++;
1879 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1880 } else {
1881 want_reread = true;
1882 kern_yield(PRI_USER);
1883 }
1884 }
1885 }
1886
1887 static struct kproc_desc vnlru_kp = {
1888 "vnlru",
1889 vnlru_proc,
1890 &vnlruproc
1891 };
1892 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1893 &vnlru_kp);
1894
1895 /*
1896 * Routines having to do with the management of the vnode table.
1897 */
1898
1899 /*
1900 * Try to recycle a freed vnode.
1901 */
1902 static int
vtryrecycle(struct vnode * vp,bool isvnlru)1903 vtryrecycle(struct vnode *vp, bool isvnlru)
1904 {
1905 struct mount *vnmp;
1906
1907 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1908 VNPASS(vp->v_holdcnt > 0, vp);
1909 /*
1910 * This vnode may found and locked via some other list, if so we
1911 * can't recycle it yet.
1912 */
1913 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1914 CTR2(KTR_VFS,
1915 "%s: impossible to recycle, vp %p lock is already held",
1916 __func__, vp);
1917 vdrop_recycle(vp);
1918 return (EWOULDBLOCK);
1919 }
1920 /*
1921 * Don't recycle if its filesystem is being suspended.
1922 */
1923 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1924 VOP_UNLOCK(vp);
1925 CTR2(KTR_VFS,
1926 "%s: impossible to recycle, cannot start the write for %p",
1927 __func__, vp);
1928 vdrop_recycle(vp);
1929 return (EBUSY);
1930 }
1931 /*
1932 * If we got this far, we need to acquire the interlock and see if
1933 * anyone picked up this vnode from another list. If not, we will
1934 * mark it with DOOMED via vgonel() so that anyone who does find it
1935 * will skip over it.
1936 */
1937 VI_LOCK(vp);
1938 if (vp->v_usecount) {
1939 VOP_UNLOCK(vp);
1940 vdropl_recycle(vp);
1941 vn_finished_write(vnmp);
1942 CTR2(KTR_VFS,
1943 "%s: impossible to recycle, %p is already referenced",
1944 __func__, vp);
1945 return (EBUSY);
1946 }
1947 if (!VN_IS_DOOMED(vp)) {
1948 if (isvnlru)
1949 recycles_free_count++;
1950 else
1951 counter_u64_add(direct_recycles_free_count, 1);
1952 vgonel(vp);
1953 }
1954 VOP_UNLOCK(vp);
1955 vdropl_recycle(vp);
1956 vn_finished_write(vnmp);
1957 return (0);
1958 }
1959
1960 /*
1961 * Allocate a new vnode.
1962 *
1963 * The operation never returns an error. Returning an error was disabled
1964 * in r145385 (dated 2005) with the following comment:
1965 *
1966 * XXX Not all VFS_VGET/ffs_vget callers check returns.
1967 *
1968 * Given the age of this commit (almost 15 years at the time of writing this
1969 * comment) restoring the ability to fail requires a significant audit of
1970 * all codepaths.
1971 *
1972 * The routine can try to free a vnode or stall for up to 1 second waiting for
1973 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation.
1974 */
1975 static u_long vn_alloc_cyclecount;
1976 static u_long vn_alloc_sleeps;
1977
1978 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, alloc_sleeps, CTLFLAG_RD, &vn_alloc_sleeps, 0,
1979 "Number of times vnode allocation blocked waiting on vnlru");
1980
1981 static struct vnode * __noinline
vn_alloc_hard(struct mount * mp,u_long rnumvnodes,bool bumped)1982 vn_alloc_hard(struct mount *mp, u_long rnumvnodes, bool bumped)
1983 {
1984 u_long rfreevnodes;
1985
1986 if (bumped) {
1987 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP) {
1988 atomic_subtract_long(&numvnodes, 1);
1989 bumped = false;
1990 }
1991 }
1992
1993 mtx_lock(&vnode_list_mtx);
1994
1995 rfreevnodes = vnlru_read_freevnodes();
1996 if (vn_alloc_cyclecount++ >= rfreevnodes) {
1997 vn_alloc_cyclecount = 0;
1998 vstir = true;
1999 }
2000 /*
2001 * Grow the vnode cache if it will not be above its target max after
2002 * growing. Otherwise, if there is at least one free vnode, try to
2003 * reclaim 1 item from it before growing the cache (possibly above its
2004 * target max if the reclamation failed or is delayed).
2005 */
2006 if (vnlru_free_locked_direct(1) > 0)
2007 goto alloc;
2008 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
2009 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) {
2010 /*
2011 * Wait for space for a new vnode.
2012 */
2013 if (bumped) {
2014 atomic_subtract_long(&numvnodes, 1);
2015 bumped = false;
2016 }
2017 mtx_lock(&vnode_list_mtx);
2018 vnlru_kick_locked();
2019 vn_alloc_sleeps++;
2020 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz);
2021 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes &&
2022 vnlru_read_freevnodes() > 1)
2023 vnlru_free_locked_direct(1);
2024 else
2025 mtx_unlock(&vnode_list_mtx);
2026 }
2027 alloc:
2028 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
2029 if (!bumped)
2030 atomic_add_long(&numvnodes, 1);
2031 vnlru_kick_cond();
2032 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2033 }
2034
2035 static struct vnode *
vn_alloc(struct mount * mp)2036 vn_alloc(struct mount *mp)
2037 {
2038 u_long rnumvnodes;
2039
2040 if (__predict_false(vn_alloc_cyclecount != 0))
2041 return (vn_alloc_hard(mp, 0, false));
2042 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1;
2043 if (__predict_false(vnlru_under(rnumvnodes, vlowat))) {
2044 return (vn_alloc_hard(mp, rnumvnodes, true));
2045 }
2046
2047 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2048 }
2049
2050 static void
vn_free(struct vnode * vp)2051 vn_free(struct vnode *vp)
2052 {
2053
2054 atomic_subtract_long(&numvnodes, 1);
2055 uma_zfree_smr(vnode_zone, vp);
2056 }
2057
2058 /*
2059 * Allocate a new vnode.
2060 */
2061 int
getnewvnode(const char * tag,struct mount * mp,struct vop_vector * vops,struct vnode ** vpp)2062 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
2063 struct vnode **vpp)
2064 {
2065 struct vnode *vp;
2066 struct thread *td;
2067 struct lock_object *lo;
2068
2069 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
2070
2071 KASSERT(vops->registered,
2072 ("%s: not registered vector op %p\n", __func__, vops));
2073 cache_validate_vop_vector(mp, vops);
2074
2075 td = curthread;
2076 if (td->td_vp_reserved != NULL) {
2077 vp = td->td_vp_reserved;
2078 td->td_vp_reserved = NULL;
2079 } else {
2080 vp = vn_alloc(mp);
2081 }
2082 counter_u64_add(vnodes_created, 1);
2083
2084 vn_set_state(vp, VSTATE_UNINITIALIZED);
2085
2086 /*
2087 * Locks are given the generic name "vnode" when created.
2088 * Follow the historic practice of using the filesystem
2089 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
2090 *
2091 * Locks live in a witness group keyed on their name. Thus,
2092 * when a lock is renamed, it must also move from the witness
2093 * group of its old name to the witness group of its new name.
2094 *
2095 * The change only needs to be made when the vnode moves
2096 * from one filesystem type to another. We ensure that each
2097 * filesystem use a single static name pointer for its tag so
2098 * that we can compare pointers rather than doing a strcmp().
2099 */
2100 lo = &vp->v_vnlock->lock_object;
2101 #ifdef WITNESS
2102 if (lo->lo_name != tag) {
2103 #endif
2104 lo->lo_name = tag;
2105 #ifdef WITNESS
2106 WITNESS_DESTROY(lo);
2107 WITNESS_INIT(lo, tag);
2108 }
2109 #endif
2110 /*
2111 * By default, don't allow shared locks unless filesystems opt-in.
2112 */
2113 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
2114 /*
2115 * Finalize various vnode identity bits.
2116 */
2117 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
2118 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
2119 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
2120 vp->v_type = VNON;
2121 vp->v_op = vops;
2122 vp->v_irflag = 0;
2123 v_init_counters(vp);
2124 vn_seqc_init(vp);
2125 vp->v_bufobj.bo_ops = &buf_ops_bio;
2126 #ifdef DIAGNOSTIC
2127 if (mp == NULL && vops != &dead_vnodeops)
2128 printf("NULL mp in getnewvnode(9), tag %s\n", tag);
2129 #endif
2130 #ifdef MAC
2131 mac_vnode_init(vp);
2132 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
2133 mac_vnode_associate_singlelabel(mp, vp);
2134 #endif
2135 if (mp != NULL) {
2136 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
2137 }
2138
2139 /*
2140 * For the filesystems which do not use vfs_hash_insert(),
2141 * still initialize v_hash to have vfs_hash_index() useful.
2142 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
2143 * its own hashing.
2144 */
2145 vp->v_hash = (uintptr_t)vp >> vnsz2log;
2146
2147 *vpp = vp;
2148 return (0);
2149 }
2150
2151 void
getnewvnode_reserve(void)2152 getnewvnode_reserve(void)
2153 {
2154 struct thread *td;
2155
2156 td = curthread;
2157 MPASS(td->td_vp_reserved == NULL);
2158 td->td_vp_reserved = vn_alloc(NULL);
2159 }
2160
2161 void
getnewvnode_drop_reserve(void)2162 getnewvnode_drop_reserve(void)
2163 {
2164 struct thread *td;
2165
2166 td = curthread;
2167 if (td->td_vp_reserved != NULL) {
2168 vn_free(td->td_vp_reserved);
2169 td->td_vp_reserved = NULL;
2170 }
2171 }
2172
2173 static void __noinline
freevnode(struct vnode * vp)2174 freevnode(struct vnode *vp)
2175 {
2176 struct bufobj *bo;
2177
2178 /*
2179 * The vnode has been marked for destruction, so free it.
2180 *
2181 * The vnode will be returned to the zone where it will
2182 * normally remain until it is needed for another vnode. We
2183 * need to cleanup (or verify that the cleanup has already
2184 * been done) any residual data left from its current use
2185 * so as not to contaminate the freshly allocated vnode.
2186 */
2187 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2188 /*
2189 * Paired with vgone.
2190 */
2191 vn_seqc_write_end_free(vp);
2192
2193 bo = &vp->v_bufobj;
2194 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2195 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp);
2196 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2197 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2198 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2199 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2200 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2201 ("clean blk trie not empty"));
2202 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2203 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2204 ("dirty blk trie not empty"));
2205 VNASSERT((vp->v_iflag & (VI_DOINGINACT | VI_OWEINACT)) == 0, vp,
2206 ("Leaked inactivation"));
2207 VI_UNLOCK(vp);
2208 cache_assert_no_entries(vp);
2209
2210 #ifdef MAC
2211 mac_vnode_destroy(vp);
2212 #endif
2213 if (vp->v_pollinfo != NULL) {
2214 /*
2215 * Use LK_NOWAIT to shut up witness about the lock. We may get
2216 * here while having another vnode locked when trying to
2217 * satisfy a lookup and needing to recycle.
2218 */
2219 VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT);
2220 destroy_vpollinfo(vp->v_pollinfo);
2221 VOP_UNLOCK(vp);
2222 vp->v_pollinfo = NULL;
2223 }
2224 vp->v_mountedhere = NULL;
2225 vp->v_unpcb = NULL;
2226 vp->v_rdev = NULL;
2227 vp->v_fifoinfo = NULL;
2228 vp->v_iflag = 0;
2229 vp->v_vflag = 0;
2230 bo->bo_flag = 0;
2231 vn_free(vp);
2232 }
2233
2234 /*
2235 * Delete from old mount point vnode list, if on one.
2236 */
2237 static void
delmntque(struct vnode * vp)2238 delmntque(struct vnode *vp)
2239 {
2240 struct mount *mp;
2241
2242 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
2243
2244 mp = vp->v_mount;
2245 MNT_ILOCK(mp);
2246 VI_LOCK(vp);
2247 vp->v_mount = NULL;
2248 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
2249 ("bad mount point vnode list size"));
2250 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2251 mp->mnt_nvnodelistsize--;
2252 MNT_REL(mp);
2253 MNT_IUNLOCK(mp);
2254 /*
2255 * The caller expects the interlock to be still held.
2256 */
2257 ASSERT_VI_LOCKED(vp, __func__);
2258 }
2259
2260 static int
insmntque1_int(struct vnode * vp,struct mount * mp,bool dtr)2261 insmntque1_int(struct vnode *vp, struct mount *mp, bool dtr)
2262 {
2263
2264 KASSERT(vp->v_mount == NULL,
2265 ("insmntque: vnode already on per mount vnode list"));
2266 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
2267 if ((mp->mnt_kern_flag & MNTK_UNLOCKED_INSMNTQUE) == 0) {
2268 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
2269 } else {
2270 KASSERT(!dtr,
2271 ("%s: can't have MNTK_UNLOCKED_INSMNTQUE and cleanup",
2272 __func__));
2273 }
2274
2275 /*
2276 * We acquire the vnode interlock early to ensure that the
2277 * vnode cannot be recycled by another process releasing a
2278 * holdcnt on it before we get it on both the vnode list
2279 * and the active vnode list. The mount mutex protects only
2280 * manipulation of the vnode list and the vnode freelist
2281 * mutex protects only manipulation of the active vnode list.
2282 * Hence the need to hold the vnode interlock throughout.
2283 */
2284 MNT_ILOCK(mp);
2285 VI_LOCK(vp);
2286 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
2287 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
2288 mp->mnt_nvnodelistsize == 0)) &&
2289 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
2290 VI_UNLOCK(vp);
2291 MNT_IUNLOCK(mp);
2292 if (dtr) {
2293 vp->v_data = NULL;
2294 vp->v_op = &dead_vnodeops;
2295 vgone(vp);
2296 vput(vp);
2297 }
2298 return (EBUSY);
2299 }
2300 vp->v_mount = mp;
2301 MNT_REF(mp);
2302 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2303 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
2304 ("neg mount point vnode list size"));
2305 mp->mnt_nvnodelistsize++;
2306 VI_UNLOCK(vp);
2307 MNT_IUNLOCK(mp);
2308 return (0);
2309 }
2310
2311 /*
2312 * Insert into list of vnodes for the new mount point, if available.
2313 * insmntque() reclaims the vnode on insertion failure, insmntque1()
2314 * leaves handling of the vnode to the caller.
2315 */
2316 int
insmntque(struct vnode * vp,struct mount * mp)2317 insmntque(struct vnode *vp, struct mount *mp)
2318 {
2319 return (insmntque1_int(vp, mp, true));
2320 }
2321
2322 int
insmntque1(struct vnode * vp,struct mount * mp)2323 insmntque1(struct vnode *vp, struct mount *mp)
2324 {
2325 return (insmntque1_int(vp, mp, false));
2326 }
2327
2328 /*
2329 * Flush out and invalidate all buffers associated with a bufobj
2330 * Called with the underlying object locked.
2331 */
2332 int
bufobj_invalbuf(struct bufobj * bo,int flags,int slpflag,int slptimeo)2333 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
2334 {
2335 int error;
2336
2337 BO_LOCK(bo);
2338 if (flags & V_SAVE) {
2339 error = bufobj_wwait(bo, slpflag, slptimeo);
2340 if (error) {
2341 BO_UNLOCK(bo);
2342 return (error);
2343 }
2344 if (bo->bo_dirty.bv_cnt > 0) {
2345 BO_UNLOCK(bo);
2346 do {
2347 error = BO_SYNC(bo, MNT_WAIT);
2348 } while (error == ERELOOKUP);
2349 if (error != 0)
2350 return (error);
2351 BO_LOCK(bo);
2352 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) {
2353 BO_UNLOCK(bo);
2354 return (EBUSY);
2355 }
2356 }
2357 }
2358 /*
2359 * If you alter this loop please notice that interlock is dropped and
2360 * reacquired in flushbuflist. Special care is needed to ensure that
2361 * no race conditions occur from this.
2362 */
2363 do {
2364 error = flushbuflist(&bo->bo_clean,
2365 flags, bo, slpflag, slptimeo);
2366 if (error == 0 && !(flags & V_CLEANONLY))
2367 error = flushbuflist(&bo->bo_dirty,
2368 flags, bo, slpflag, slptimeo);
2369 if (error != 0 && error != EAGAIN) {
2370 BO_UNLOCK(bo);
2371 return (error);
2372 }
2373 } while (error != 0);
2374
2375 /*
2376 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
2377 * have write I/O in-progress but if there is a VM object then the
2378 * VM object can also have read-I/O in-progress.
2379 */
2380 do {
2381 bufobj_wwait(bo, 0, 0);
2382 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) {
2383 BO_UNLOCK(bo);
2384 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx");
2385 BO_LOCK(bo);
2386 }
2387 } while (bo->bo_numoutput > 0);
2388 BO_UNLOCK(bo);
2389
2390 /*
2391 * Destroy the copy in the VM cache, too.
2392 */
2393 if (bo->bo_object != NULL &&
2394 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
2395 VM_OBJECT_WLOCK(bo->bo_object);
2396 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
2397 OBJPR_CLEANONLY : 0);
2398 VM_OBJECT_WUNLOCK(bo->bo_object);
2399 }
2400
2401 #ifdef INVARIANTS
2402 BO_LOCK(bo);
2403 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO |
2404 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 ||
2405 bo->bo_clean.bv_cnt > 0))
2406 panic("vinvalbuf: flush failed");
2407 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
2408 bo->bo_dirty.bv_cnt > 0)
2409 panic("vinvalbuf: flush dirty failed");
2410 BO_UNLOCK(bo);
2411 #endif
2412 return (0);
2413 }
2414
2415 /*
2416 * Flush out and invalidate all buffers associated with a vnode.
2417 * Called with the underlying object locked.
2418 */
2419 int
vinvalbuf(struct vnode * vp,int flags,int slpflag,int slptimeo)2420 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
2421 {
2422
2423 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2424 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
2425 if (vp->v_object != NULL && vp->v_object->handle != vp)
2426 return (0);
2427 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
2428 }
2429
2430 /*
2431 * Flush out buffers on the specified list.
2432 *
2433 */
2434 static int
flushbuflist(struct bufv * bufv,int flags,struct bufobj * bo,int slpflag,int slptimeo)2435 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
2436 int slptimeo)
2437 {
2438 struct buf *bp, *nbp;
2439 int retval, error;
2440 daddr_t lblkno;
2441 b_xflags_t xflags;
2442
2443 ASSERT_BO_WLOCKED(bo);
2444
2445 retval = 0;
2446 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
2447 /*
2448 * If we are flushing both V_NORMAL and V_ALT buffers then
2449 * do not skip any buffers. If we are flushing only V_NORMAL
2450 * buffers then skip buffers marked as BX_ALTDATA. If we are
2451 * flushing only V_ALT buffers then skip buffers not marked
2452 * as BX_ALTDATA.
2453 */
2454 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) &&
2455 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) ||
2456 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) {
2457 continue;
2458 }
2459 if (nbp != NULL) {
2460 lblkno = nbp->b_lblkno;
2461 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
2462 }
2463 retval = EAGAIN;
2464 error = BUF_TIMELOCK(bp,
2465 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
2466 "flushbuf", slpflag, slptimeo);
2467 if (error) {
2468 BO_LOCK(bo);
2469 return (error != ENOLCK ? error : EAGAIN);
2470 }
2471 KASSERT(bp->b_bufobj == bo,
2472 ("bp %p wrong b_bufobj %p should be %p",
2473 bp, bp->b_bufobj, bo));
2474 /*
2475 * XXX Since there are no node locks for NFS, I
2476 * believe there is a slight chance that a delayed
2477 * write will occur while sleeping just above, so
2478 * check for it.
2479 */
2480 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
2481 (flags & V_SAVE)) {
2482 bremfree(bp);
2483 bp->b_flags |= B_ASYNC;
2484 bwrite(bp);
2485 BO_LOCK(bo);
2486 return (EAGAIN); /* XXX: why not loop ? */
2487 }
2488 bremfree(bp);
2489 bp->b_flags |= (B_INVAL | B_RELBUF);
2490 bp->b_flags &= ~B_ASYNC;
2491 brelse(bp);
2492 BO_LOCK(bo);
2493 if (nbp == NULL)
2494 break;
2495 nbp = gbincore(bo, lblkno);
2496 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2497 != xflags)
2498 break; /* nbp invalid */
2499 }
2500 return (retval);
2501 }
2502
2503 int
bnoreuselist(struct bufv * bufv,struct bufobj * bo,daddr_t startn,daddr_t endn)2504 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
2505 {
2506 struct buf *bp;
2507 int error;
2508 daddr_t lblkno;
2509
2510 ASSERT_BO_LOCKED(bo);
2511
2512 for (lblkno = startn;;) {
2513 again:
2514 bp = buf_lookup_ge(bufv, lblkno);
2515 if (bp == NULL || bp->b_lblkno >= endn)
2516 break;
2517 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
2518 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
2519 if (error != 0) {
2520 BO_RLOCK(bo);
2521 if (error == ENOLCK)
2522 goto again;
2523 return (error);
2524 }
2525 KASSERT(bp->b_bufobj == bo,
2526 ("bp %p wrong b_bufobj %p should be %p",
2527 bp, bp->b_bufobj, bo));
2528 lblkno = bp->b_lblkno + 1;
2529 if ((bp->b_flags & B_MANAGED) == 0)
2530 bremfree(bp);
2531 bp->b_flags |= B_RELBUF;
2532 /*
2533 * In the VMIO case, use the B_NOREUSE flag to hint that the
2534 * pages backing each buffer in the range are unlikely to be
2535 * reused. Dirty buffers will have the hint applied once
2536 * they've been written.
2537 */
2538 if ((bp->b_flags & B_VMIO) != 0)
2539 bp->b_flags |= B_NOREUSE;
2540 brelse(bp);
2541 BO_RLOCK(bo);
2542 }
2543 return (0);
2544 }
2545
2546 /*
2547 * Truncate a file's buffer and pages to a specified length. This
2548 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
2549 * sync activity.
2550 */
2551 int
vtruncbuf(struct vnode * vp,off_t length,int blksize)2552 vtruncbuf(struct vnode *vp, off_t length, int blksize)
2553 {
2554 struct buf *bp, *nbp;
2555 struct bufobj *bo;
2556 daddr_t startlbn;
2557
2558 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__,
2559 vp, blksize, (uintmax_t)length);
2560
2561 /*
2562 * Round up to the *next* lbn.
2563 */
2564 startlbn = howmany(length, blksize);
2565
2566 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
2567
2568 bo = &vp->v_bufobj;
2569 restart_unlocked:
2570 BO_LOCK(bo);
2571
2572 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN)
2573 ;
2574
2575 if (length > 0) {
2576 /*
2577 * Write out vnode metadata, e.g. indirect blocks.
2578 */
2579 restartsync:
2580 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2581 if (bp->b_lblkno >= 0)
2582 continue;
2583 /*
2584 * Since we hold the vnode lock this should only
2585 * fail if we're racing with the buf daemon.
2586 */
2587 if (BUF_LOCK(bp,
2588 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2589 BO_LOCKPTR(bo)) == ENOLCK)
2590 goto restart_unlocked;
2591
2592 VNASSERT((bp->b_flags & B_DELWRI), vp,
2593 ("buf(%p) on dirty queue without DELWRI", bp));
2594
2595 bremfree(bp);
2596 bawrite(bp);
2597 BO_LOCK(bo);
2598 goto restartsync;
2599 }
2600 }
2601
2602 bufobj_wwait(bo, 0, 0);
2603 BO_UNLOCK(bo);
2604 vnode_pager_setsize(vp, length);
2605
2606 return (0);
2607 }
2608
2609 /*
2610 * Invalidate the cached pages of a file's buffer within the range of block
2611 * numbers [startlbn, endlbn).
2612 */
2613 void
v_inval_buf_range(struct vnode * vp,daddr_t startlbn,daddr_t endlbn,int blksize)2614 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn,
2615 int blksize)
2616 {
2617 struct bufobj *bo;
2618 off_t start, end;
2619
2620 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range");
2621
2622 start = blksize * startlbn;
2623 end = blksize * endlbn;
2624
2625 bo = &vp->v_bufobj;
2626 BO_LOCK(bo);
2627 MPASS(blksize == bo->bo_bsize);
2628
2629 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN)
2630 ;
2631
2632 BO_UNLOCK(bo);
2633 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1));
2634 }
2635
2636 static int
v_inval_buf_range_locked(struct vnode * vp,struct bufobj * bo,daddr_t startlbn,daddr_t endlbn)2637 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
2638 daddr_t startlbn, daddr_t endlbn)
2639 {
2640 struct bufv *bv;
2641 struct buf *bp, *nbp;
2642 uint8_t anyfreed;
2643 bool clean;
2644
2645 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked");
2646 ASSERT_BO_LOCKED(bo);
2647
2648 anyfreed = 1;
2649 clean = true;
2650 do {
2651 bv = clean ? &bo->bo_clean : &bo->bo_dirty;
2652 bp = buf_lookup_ge(bv, startlbn);
2653 if (bp == NULL)
2654 continue;
2655 TAILQ_FOREACH_FROM_SAFE(bp, &bv->bv_hd, b_bobufs, nbp) {
2656 if (bp->b_lblkno >= endlbn)
2657 break;
2658 if (BUF_LOCK(bp,
2659 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2660 BO_LOCKPTR(bo)) == ENOLCK) {
2661 BO_LOCK(bo);
2662 return (EAGAIN);
2663 }
2664
2665 bremfree(bp);
2666 bp->b_flags |= B_INVAL | B_RELBUF;
2667 bp->b_flags &= ~B_ASYNC;
2668 brelse(bp);
2669 anyfreed = 2;
2670
2671 BO_LOCK(bo);
2672 if (nbp != NULL &&
2673 (((nbp->b_xflags &
2674 (clean ? BX_VNCLEAN : BX_VNDIRTY)) == 0) ||
2675 nbp->b_vp != vp ||
2676 (nbp->b_flags & B_DELWRI) == (clean? B_DELWRI: 0)))
2677 return (EAGAIN);
2678 }
2679 } while (clean = !clean, anyfreed-- > 0);
2680 return (0);
2681 }
2682
2683 static void
buf_vlist_remove(struct buf * bp)2684 buf_vlist_remove(struct buf *bp)
2685 {
2686 struct bufv *bv;
2687 b_xflags_t flags;
2688
2689 flags = bp->b_xflags;
2690
2691 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
2692 ASSERT_BO_WLOCKED(bp->b_bufobj);
2693 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 &&
2694 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN),
2695 ("%s: buffer %p has invalid queue state", __func__, bp));
2696
2697 if ((flags & BX_VNDIRTY) != 0)
2698 bv = &bp->b_bufobj->bo_dirty;
2699 else
2700 bv = &bp->b_bufobj->bo_clean;
2701 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
2702 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
2703 bv->bv_cnt--;
2704 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
2705 }
2706
2707 /*
2708 * Add the buffer to the sorted clean or dirty block list. Return zero on
2709 * success, EEXIST if a buffer with this identity already exists, or another
2710 * error on allocation failure.
2711 */
2712 static inline int
buf_vlist_find_or_add(struct buf * bp,struct bufobj * bo,b_xflags_t xflags)2713 buf_vlist_find_or_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2714 {
2715 struct bufv *bv;
2716 struct buf *n;
2717 int error;
2718
2719 ASSERT_BO_WLOCKED(bo);
2720 KASSERT((bo->bo_flag & BO_NOBUFS) == 0,
2721 ("buf_vlist_add: bo %p does not allow bufs", bo));
2722 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
2723 ("dead bo %p", bo));
2724 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == xflags,
2725 ("buf_vlist_add: b_xflags %#x not set on bp %p", xflags, bp));
2726
2727 if (xflags & BX_VNDIRTY)
2728 bv = &bo->bo_dirty;
2729 else
2730 bv = &bo->bo_clean;
2731
2732 error = buf_insert_lookup_le(bv, bp, &n);
2733 if (n == NULL) {
2734 KASSERT(error != EEXIST,
2735 ("buf_vlist_add: EEXIST but no existing buf found: bp %p",
2736 bp));
2737 } else {
2738 KASSERT(n->b_lblkno <= bp->b_lblkno,
2739 ("buf_vlist_add: out of order insert/lookup: bp %p n %p",
2740 bp, n));
2741 KASSERT((n->b_lblkno == bp->b_lblkno) == (error == EEXIST),
2742 ("buf_vlist_add: inconsistent result for existing buf: "
2743 "error %d bp %p n %p", error, bp, n));
2744 }
2745 if (error != 0)
2746 return (error);
2747
2748 /* Keep the list ordered. */
2749 if (n == NULL) {
2750 KASSERT(TAILQ_EMPTY(&bv->bv_hd) ||
2751 bp->b_lblkno < TAILQ_FIRST(&bv->bv_hd)->b_lblkno,
2752 ("buf_vlist_add: queue order: "
2753 "%p should be before first %p",
2754 bp, TAILQ_FIRST(&bv->bv_hd)));
2755 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
2756 } else {
2757 KASSERT(TAILQ_NEXT(n, b_bobufs) == NULL ||
2758 bp->b_lblkno < TAILQ_NEXT(n, b_bobufs)->b_lblkno,
2759 ("buf_vlist_add: queue order: "
2760 "%p should be before next %p",
2761 bp, TAILQ_NEXT(n, b_bobufs)));
2762 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
2763 }
2764
2765 bv->bv_cnt++;
2766 return (0);
2767 }
2768
2769 /*
2770 * Add the buffer to the sorted clean or dirty block list.
2771 *
2772 * NOTE: xflags is passed as a constant, optimizing this inline function!
2773 */
2774 static void
buf_vlist_add(struct buf * bp,struct bufobj * bo,b_xflags_t xflags)2775 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2776 {
2777 int error;
2778
2779 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
2780 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
2781 bp->b_xflags |= xflags;
2782 error = buf_vlist_find_or_add(bp, bo, xflags);
2783 if (error)
2784 panic("buf_vlist_add: error=%d", error);
2785 }
2786
2787 /*
2788 * Look up a buffer using the buffer tries.
2789 */
2790 struct buf *
gbincore(struct bufobj * bo,daddr_t lblkno)2791 gbincore(struct bufobj *bo, daddr_t lblkno)
2792 {
2793 struct buf *bp;
2794
2795 ASSERT_BO_LOCKED(bo);
2796 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
2797 if (bp != NULL)
2798 return (bp);
2799 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno));
2800 }
2801
2802 /*
2803 * Look up a buf using the buffer tries, without the bufobj lock. This relies
2804 * on SMR for safe lookup, and bufs being in a no-free zone to provide type
2805 * stability of the result. Like other lockless lookups, the found buf may
2806 * already be invalid by the time this function returns.
2807 */
2808 struct buf *
gbincore_unlocked(struct bufobj * bo,daddr_t lblkno)2809 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno)
2810 {
2811 struct buf *bp;
2812
2813 ASSERT_BO_UNLOCKED(bo);
2814 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno);
2815 if (bp != NULL)
2816 return (bp);
2817 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno));
2818 }
2819
2820 /*
2821 * Associate a buffer with a vnode.
2822 */
2823 int
bgetvp(struct vnode * vp,struct buf * bp)2824 bgetvp(struct vnode *vp, struct buf *bp)
2825 {
2826 struct bufobj *bo;
2827 int error;
2828
2829 bo = &vp->v_bufobj;
2830 ASSERT_BO_UNLOCKED(bo);
2831 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
2832
2833 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
2834 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
2835 ("bgetvp: bp already attached! %p", bp));
2836
2837 /*
2838 * Add the buf to the vnode's clean list unless we lost a race and find
2839 * an existing buf in either dirty or clean.
2840 */
2841 bp->b_vp = vp;
2842 bp->b_bufobj = bo;
2843 bp->b_xflags |= BX_VNCLEAN;
2844 error = EEXIST;
2845 BO_LOCK(bo);
2846 if (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, bp->b_lblkno) == NULL)
2847 error = buf_vlist_find_or_add(bp, bo, BX_VNCLEAN);
2848 BO_UNLOCK(bo);
2849 if (__predict_true(error == 0)) {
2850 vhold(vp);
2851 return (0);
2852 }
2853 if (error != EEXIST)
2854 panic("bgetvp: buf_vlist_add error: %d", error);
2855 bp->b_vp = NULL;
2856 bp->b_bufobj = NULL;
2857 bp->b_xflags &= ~BX_VNCLEAN;
2858 return (error);
2859 }
2860
2861 /*
2862 * Disassociate a buffer from a vnode.
2863 */
2864 void
brelvp(struct buf * bp)2865 brelvp(struct buf *bp)
2866 {
2867 struct bufobj *bo;
2868 struct vnode *vp;
2869
2870 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
2871 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
2872
2873 /*
2874 * Delete from old vnode list, if on one.
2875 */
2876 vp = bp->b_vp; /* XXX */
2877 bo = bp->b_bufobj;
2878 BO_LOCK(bo);
2879 buf_vlist_remove(bp);
2880 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2881 bo->bo_flag &= ~BO_ONWORKLST;
2882 mtx_lock(&sync_mtx);
2883 LIST_REMOVE(bo, bo_synclist);
2884 syncer_worklist_len--;
2885 mtx_unlock(&sync_mtx);
2886 }
2887 bp->b_vp = NULL;
2888 bp->b_bufobj = NULL;
2889 BO_UNLOCK(bo);
2890 vdrop(vp);
2891 }
2892
2893 /*
2894 * Add an item to the syncer work queue.
2895 */
2896 static void
vn_syncer_add_to_worklist(struct bufobj * bo,int delay)2897 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2898 {
2899 int slot;
2900
2901 ASSERT_BO_WLOCKED(bo);
2902
2903 mtx_lock(&sync_mtx);
2904 if (bo->bo_flag & BO_ONWORKLST)
2905 LIST_REMOVE(bo, bo_synclist);
2906 else {
2907 bo->bo_flag |= BO_ONWORKLST;
2908 syncer_worklist_len++;
2909 }
2910
2911 if (delay > syncer_maxdelay - 2)
2912 delay = syncer_maxdelay - 2;
2913 slot = (syncer_delayno + delay) & syncer_mask;
2914
2915 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2916 mtx_unlock(&sync_mtx);
2917 }
2918
2919 static int
sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)2920 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2921 {
2922 int error, len;
2923
2924 mtx_lock(&sync_mtx);
2925 len = syncer_worklist_len - sync_vnode_count;
2926 mtx_unlock(&sync_mtx);
2927 error = SYSCTL_OUT(req, &len, sizeof(len));
2928 return (error);
2929 }
2930
2931 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len,
2932 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0,
2933 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2934
2935 static struct proc *updateproc;
2936 static void sched_sync(void);
2937 static struct kproc_desc up_kp = {
2938 "syncer",
2939 sched_sync,
2940 &updateproc
2941 };
2942 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2943
2944 static int
sync_vnode(struct synclist * slp,struct bufobj ** bo,struct thread * td)2945 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2946 {
2947 struct vnode *vp;
2948 struct mount *mp;
2949
2950 *bo = LIST_FIRST(slp);
2951 if (*bo == NULL)
2952 return (0);
2953 vp = bo2vnode(*bo);
2954 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2955 return (1);
2956 /*
2957 * We use vhold in case the vnode does not
2958 * successfully sync. vhold prevents the vnode from
2959 * going away when we unlock the sync_mtx so that
2960 * we can acquire the vnode interlock.
2961 */
2962 vholdl(vp);
2963 mtx_unlock(&sync_mtx);
2964 VI_UNLOCK(vp);
2965 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2966 vdrop(vp);
2967 mtx_lock(&sync_mtx);
2968 return (*bo == LIST_FIRST(slp));
2969 }
2970 MPASSERT(mp == NULL || (curthread->td_pflags & TDP_IGNSUSP) != 0 ||
2971 (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0, mp,
2972 ("suspended mp syncing vp %p", vp));
2973 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2974 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2975 VOP_UNLOCK(vp);
2976 vn_finished_write(mp);
2977 BO_LOCK(*bo);
2978 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2979 /*
2980 * Put us back on the worklist. The worklist
2981 * routine will remove us from our current
2982 * position and then add us back in at a later
2983 * position.
2984 */
2985 vn_syncer_add_to_worklist(*bo, syncdelay);
2986 }
2987 BO_UNLOCK(*bo);
2988 vdrop(vp);
2989 mtx_lock(&sync_mtx);
2990 return (0);
2991 }
2992
2993 static int first_printf = 1;
2994
2995 /*
2996 * System filesystem synchronizer daemon.
2997 */
2998 static void
sched_sync(void)2999 sched_sync(void)
3000 {
3001 struct synclist *next, *slp;
3002 struct bufobj *bo;
3003 long starttime;
3004 struct thread *td = curthread;
3005 int last_work_seen;
3006 int net_worklist_len;
3007 int syncer_final_iter;
3008 int error;
3009
3010 last_work_seen = 0;
3011 syncer_final_iter = 0;
3012 syncer_state = SYNCER_RUNNING;
3013 starttime = time_uptime;
3014 td->td_pflags |= TDP_NORUNNINGBUF;
3015
3016 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
3017 SHUTDOWN_PRI_LAST);
3018
3019 mtx_lock(&sync_mtx);
3020 for (;;) {
3021 if (syncer_state == SYNCER_FINAL_DELAY &&
3022 syncer_final_iter == 0) {
3023 mtx_unlock(&sync_mtx);
3024 kproc_suspend_check(td->td_proc);
3025 mtx_lock(&sync_mtx);
3026 }
3027 net_worklist_len = syncer_worklist_len - sync_vnode_count;
3028 if (syncer_state != SYNCER_RUNNING &&
3029 starttime != time_uptime) {
3030 if (first_printf) {
3031 printf("\nSyncing disks, vnodes remaining... ");
3032 first_printf = 0;
3033 }
3034 printf("%d ", net_worklist_len);
3035 }
3036 starttime = time_uptime;
3037
3038 /*
3039 * Push files whose dirty time has expired. Be careful
3040 * of interrupt race on slp queue.
3041 *
3042 * Skip over empty worklist slots when shutting down.
3043 */
3044 do {
3045 slp = &syncer_workitem_pending[syncer_delayno];
3046 syncer_delayno += 1;
3047 if (syncer_delayno == syncer_maxdelay)
3048 syncer_delayno = 0;
3049 next = &syncer_workitem_pending[syncer_delayno];
3050 /*
3051 * If the worklist has wrapped since the
3052 * it was emptied of all but syncer vnodes,
3053 * switch to the FINAL_DELAY state and run
3054 * for one more second.
3055 */
3056 if (syncer_state == SYNCER_SHUTTING_DOWN &&
3057 net_worklist_len == 0 &&
3058 last_work_seen == syncer_delayno) {
3059 syncer_state = SYNCER_FINAL_DELAY;
3060 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
3061 }
3062 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
3063 syncer_worklist_len > 0);
3064
3065 /*
3066 * Keep track of the last time there was anything
3067 * on the worklist other than syncer vnodes.
3068 * Return to the SHUTTING_DOWN state if any
3069 * new work appears.
3070 */
3071 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
3072 last_work_seen = syncer_delayno;
3073 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
3074 syncer_state = SYNCER_SHUTTING_DOWN;
3075 while (!LIST_EMPTY(slp)) {
3076 error = sync_vnode(slp, &bo, td);
3077 if (error == 1) {
3078 LIST_REMOVE(bo, bo_synclist);
3079 LIST_INSERT_HEAD(next, bo, bo_synclist);
3080 continue;
3081 }
3082
3083 if (first_printf == 0) {
3084 /*
3085 * Drop the sync mutex, because some watchdog
3086 * drivers need to sleep while patting
3087 */
3088 mtx_unlock(&sync_mtx);
3089 wdog_kern_pat(WD_LASTVAL);
3090 mtx_lock(&sync_mtx);
3091 }
3092 }
3093 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
3094 syncer_final_iter--;
3095 /*
3096 * The variable rushjob allows the kernel to speed up the
3097 * processing of the filesystem syncer process. A rushjob
3098 * value of N tells the filesystem syncer to process the next
3099 * N seconds worth of work on its queue ASAP. Currently rushjob
3100 * is used by the soft update code to speed up the filesystem
3101 * syncer process when the incore state is getting so far
3102 * ahead of the disk that the kernel memory pool is being
3103 * threatened with exhaustion.
3104 */
3105 if (rushjob > 0) {
3106 rushjob -= 1;
3107 continue;
3108 }
3109 /*
3110 * Just sleep for a short period of time between
3111 * iterations when shutting down to allow some I/O
3112 * to happen.
3113 *
3114 * If it has taken us less than a second to process the
3115 * current work, then wait. Otherwise start right over
3116 * again. We can still lose time if any single round
3117 * takes more than two seconds, but it does not really
3118 * matter as we are just trying to generally pace the
3119 * filesystem activity.
3120 */
3121 if (syncer_state != SYNCER_RUNNING ||
3122 time_uptime == starttime) {
3123 thread_lock(td);
3124 sched_prio(td, PPAUSE);
3125 thread_unlock(td);
3126 }
3127 if (syncer_state != SYNCER_RUNNING)
3128 cv_timedwait(&sync_wakeup, &sync_mtx,
3129 hz / SYNCER_SHUTDOWN_SPEEDUP);
3130 else if (time_uptime == starttime)
3131 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
3132 }
3133 }
3134
3135 /*
3136 * Request the syncer daemon to speed up its work.
3137 * We never push it to speed up more than half of its
3138 * normal turn time, otherwise it could take over the cpu.
3139 */
3140 int
speedup_syncer(void)3141 speedup_syncer(void)
3142 {
3143 int ret = 0;
3144
3145 mtx_lock(&sync_mtx);
3146 if (rushjob < syncdelay / 2) {
3147 rushjob += 1;
3148 stat_rush_requests += 1;
3149 ret = 1;
3150 }
3151 mtx_unlock(&sync_mtx);
3152 cv_broadcast(&sync_wakeup);
3153 return (ret);
3154 }
3155
3156 /*
3157 * Tell the syncer to speed up its work and run though its work
3158 * list several times, then tell it to shut down.
3159 */
3160 static void
syncer_shutdown(void * arg,int howto)3161 syncer_shutdown(void *arg, int howto)
3162 {
3163
3164 if (howto & RB_NOSYNC)
3165 return;
3166 mtx_lock(&sync_mtx);
3167 syncer_state = SYNCER_SHUTTING_DOWN;
3168 rushjob = 0;
3169 mtx_unlock(&sync_mtx);
3170 cv_broadcast(&sync_wakeup);
3171 kproc_shutdown(arg, howto);
3172 }
3173
3174 void
syncer_suspend(void)3175 syncer_suspend(void)
3176 {
3177
3178 syncer_shutdown(updateproc, 0);
3179 }
3180
3181 void
syncer_resume(void)3182 syncer_resume(void)
3183 {
3184
3185 mtx_lock(&sync_mtx);
3186 first_printf = 1;
3187 syncer_state = SYNCER_RUNNING;
3188 mtx_unlock(&sync_mtx);
3189 cv_broadcast(&sync_wakeup);
3190 kproc_resume(updateproc);
3191 }
3192
3193 /*
3194 * Move the buffer between the clean and dirty lists of its vnode.
3195 */
3196 void
reassignbuf(struct buf * bp)3197 reassignbuf(struct buf *bp)
3198 {
3199 struct vnode *vp;
3200 struct bufobj *bo;
3201 int delay;
3202 #ifdef INVARIANTS
3203 struct bufv *bv;
3204 #endif
3205
3206 vp = bp->b_vp;
3207 bo = bp->b_bufobj;
3208
3209 KASSERT((bp->b_flags & B_PAGING) == 0,
3210 ("%s: cannot reassign paging buffer %p", __func__, bp));
3211
3212 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
3213 bp, bp->b_vp, bp->b_flags);
3214
3215 BO_LOCK(bo);
3216 if ((bo->bo_flag & BO_NONSTERILE) == 0) {
3217 /*
3218 * Coordinate with getblk's unlocked lookup. Make
3219 * BO_NONSTERILE visible before the first reassignbuf produces
3220 * any side effect. This could be outside the bo lock if we
3221 * used a separate atomic flag field.
3222 */
3223 bo->bo_flag |= BO_NONSTERILE;
3224 atomic_thread_fence_rel();
3225 }
3226 buf_vlist_remove(bp);
3227
3228 /*
3229 * If dirty, put on list of dirty buffers; otherwise insert onto list
3230 * of clean buffers.
3231 */
3232 if (bp->b_flags & B_DELWRI) {
3233 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
3234 switch (vp->v_type) {
3235 case VDIR:
3236 delay = dirdelay;
3237 break;
3238 case VCHR:
3239 delay = metadelay;
3240 break;
3241 default:
3242 delay = filedelay;
3243 }
3244 vn_syncer_add_to_worklist(bo, delay);
3245 }
3246 buf_vlist_add(bp, bo, BX_VNDIRTY);
3247 } else {
3248 buf_vlist_add(bp, bo, BX_VNCLEAN);
3249
3250 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
3251 mtx_lock(&sync_mtx);
3252 LIST_REMOVE(bo, bo_synclist);
3253 syncer_worklist_len--;
3254 mtx_unlock(&sync_mtx);
3255 bo->bo_flag &= ~BO_ONWORKLST;
3256 }
3257 }
3258 #ifdef INVARIANTS
3259 bv = &bo->bo_clean;
3260 bp = TAILQ_FIRST(&bv->bv_hd);
3261 KASSERT(bp == NULL || bp->b_bufobj == bo,
3262 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3263 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3264 KASSERT(bp == NULL || bp->b_bufobj == bo,
3265 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3266 bv = &bo->bo_dirty;
3267 bp = TAILQ_FIRST(&bv->bv_hd);
3268 KASSERT(bp == NULL || bp->b_bufobj == bo,
3269 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3270 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3271 KASSERT(bp == NULL || bp->b_bufobj == bo,
3272 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3273 #endif
3274 BO_UNLOCK(bo);
3275 }
3276
3277 static void
v_init_counters(struct vnode * vp)3278 v_init_counters(struct vnode *vp)
3279 {
3280
3281 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
3282 vp, ("%s called for an initialized vnode", __FUNCTION__));
3283 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
3284
3285 refcount_init(&vp->v_holdcnt, 1);
3286 refcount_init(&vp->v_usecount, 1);
3287 }
3288
3289 /*
3290 * Get a usecount on a vnode.
3291 *
3292 * vget and vget_finish may fail to lock the vnode if they lose a race against
3293 * it being doomed. LK_RETRY can be passed in flags to lock it anyway.
3294 *
3295 * Consumers which don't guarantee liveness of the vnode can use SMR to
3296 * try to get a reference. Note this operation can fail since the vnode
3297 * may be awaiting getting freed by the time they get to it.
3298 */
3299 enum vgetstate
vget_prep_smr(struct vnode * vp)3300 vget_prep_smr(struct vnode *vp)
3301 {
3302 enum vgetstate vs;
3303
3304 VFS_SMR_ASSERT_ENTERED();
3305
3306 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3307 vs = VGET_USECOUNT;
3308 } else {
3309 if (vhold_smr(vp))
3310 vs = VGET_HOLDCNT;
3311 else
3312 vs = VGET_NONE;
3313 }
3314 return (vs);
3315 }
3316
3317 enum vgetstate
vget_prep(struct vnode * vp)3318 vget_prep(struct vnode *vp)
3319 {
3320 enum vgetstate vs;
3321
3322 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3323 vs = VGET_USECOUNT;
3324 } else {
3325 vhold(vp);
3326 vs = VGET_HOLDCNT;
3327 }
3328 return (vs);
3329 }
3330
3331 void
vget_abort(struct vnode * vp,enum vgetstate vs)3332 vget_abort(struct vnode *vp, enum vgetstate vs)
3333 {
3334
3335 switch (vs) {
3336 case VGET_USECOUNT:
3337 vrele(vp);
3338 break;
3339 case VGET_HOLDCNT:
3340 vdrop(vp);
3341 break;
3342 default:
3343 __assert_unreachable();
3344 }
3345 }
3346
3347 int
vget(struct vnode * vp,int flags)3348 vget(struct vnode *vp, int flags)
3349 {
3350 enum vgetstate vs;
3351
3352 vs = vget_prep(vp);
3353 return (vget_finish(vp, flags, vs));
3354 }
3355
3356 int
vget_finish(struct vnode * vp,int flags,enum vgetstate vs)3357 vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
3358 {
3359 int error;
3360
3361 if ((flags & LK_INTERLOCK) != 0)
3362 ASSERT_VI_LOCKED(vp, __func__);
3363 else
3364 ASSERT_VI_UNLOCKED(vp, __func__);
3365 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3366 VNPASS(vp->v_holdcnt > 0, vp);
3367 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3368
3369 error = vn_lock(vp, flags);
3370 if (__predict_false(error != 0)) {
3371 vget_abort(vp, vs);
3372 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
3373 vp);
3374 return (error);
3375 }
3376
3377 vget_finish_ref(vp, vs);
3378 return (0);
3379 }
3380
3381 void
vget_finish_ref(struct vnode * vp,enum vgetstate vs)3382 vget_finish_ref(struct vnode *vp, enum vgetstate vs)
3383 {
3384 int old;
3385
3386 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3387 VNPASS(vp->v_holdcnt > 0, vp);
3388 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3389
3390 if (vs == VGET_USECOUNT)
3391 return;
3392
3393 /*
3394 * We hold the vnode. If the usecount is 0 it will be utilized to keep
3395 * the vnode around. Otherwise someone else lended their hold count and
3396 * we have to drop ours.
3397 */
3398 old = atomic_fetchadd_int(&vp->v_usecount, 1);
3399 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old));
3400 if (old != 0) {
3401 #ifdef INVARIANTS
3402 old = atomic_fetchadd_int(&vp->v_holdcnt, -1);
3403 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old));
3404 #else
3405 refcount_release(&vp->v_holdcnt);
3406 #endif
3407 }
3408 }
3409
3410 void
vref(struct vnode * vp)3411 vref(struct vnode *vp)
3412 {
3413 enum vgetstate vs;
3414
3415 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3416 vs = vget_prep(vp);
3417 vget_finish_ref(vp, vs);
3418 }
3419
3420 void
vrefact(struct vnode * vp)3421 vrefact(struct vnode *vp)
3422 {
3423 int old __diagused;
3424
3425 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3426 old = refcount_acquire(&vp->v_usecount);
3427 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old));
3428 }
3429
3430 void
vlazy(struct vnode * vp)3431 vlazy(struct vnode *vp)
3432 {
3433 struct mount *mp;
3434
3435 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__));
3436
3437 if ((vp->v_mflag & VMP_LAZYLIST) != 0)
3438 return;
3439 /*
3440 * We may get here for inactive routines after the vnode got doomed.
3441 */
3442 if (VN_IS_DOOMED(vp))
3443 return;
3444 mp = vp->v_mount;
3445 mtx_lock(&mp->mnt_listmtx);
3446 if ((vp->v_mflag & VMP_LAZYLIST) == 0) {
3447 vp->v_mflag |= VMP_LAZYLIST;
3448 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3449 mp->mnt_lazyvnodelistsize++;
3450 }
3451 mtx_unlock(&mp->mnt_listmtx);
3452 }
3453
3454 static void
vunlazy(struct vnode * vp)3455 vunlazy(struct vnode *vp)
3456 {
3457 struct mount *mp;
3458
3459 ASSERT_VI_LOCKED(vp, __func__);
3460 VNPASS(!VN_IS_DOOMED(vp), vp);
3461
3462 mp = vp->v_mount;
3463 mtx_lock(&mp->mnt_listmtx);
3464 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3465 /*
3466 * Don't remove the vnode from the lazy list if another thread
3467 * has increased the hold count. It may have re-enqueued the
3468 * vnode to the lazy list and is now responsible for its
3469 * removal.
3470 */
3471 if (vp->v_holdcnt == 0) {
3472 vp->v_mflag &= ~VMP_LAZYLIST;
3473 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3474 mp->mnt_lazyvnodelistsize--;
3475 }
3476 mtx_unlock(&mp->mnt_listmtx);
3477 }
3478
3479 /*
3480 * This routine is only meant to be called from vgonel prior to dooming
3481 * the vnode.
3482 */
3483 static void
vunlazy_gone(struct vnode * vp)3484 vunlazy_gone(struct vnode *vp)
3485 {
3486 struct mount *mp;
3487
3488 ASSERT_VOP_ELOCKED(vp, __func__);
3489 ASSERT_VI_LOCKED(vp, __func__);
3490 VNPASS(!VN_IS_DOOMED(vp), vp);
3491
3492 if (vp->v_mflag & VMP_LAZYLIST) {
3493 mp = vp->v_mount;
3494 mtx_lock(&mp->mnt_listmtx);
3495 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3496 vp->v_mflag &= ~VMP_LAZYLIST;
3497 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3498 mp->mnt_lazyvnodelistsize--;
3499 mtx_unlock(&mp->mnt_listmtx);
3500 }
3501 }
3502
3503 static void
vdefer_inactive(struct vnode * vp)3504 vdefer_inactive(struct vnode *vp)
3505 {
3506
3507 ASSERT_VI_LOCKED(vp, __func__);
3508 VNPASS(vp->v_holdcnt > 0, vp);
3509 if (VN_IS_DOOMED(vp)) {
3510 vdropl(vp);
3511 return;
3512 }
3513 if (vp->v_iflag & VI_DEFINACT) {
3514 VNPASS(vp->v_holdcnt > 1, vp);
3515 vdropl(vp);
3516 return;
3517 }
3518 if (vp->v_usecount > 0) {
3519 vp->v_iflag &= ~VI_OWEINACT;
3520 vdropl(vp);
3521 return;
3522 }
3523 vlazy(vp);
3524 vp->v_iflag |= VI_DEFINACT;
3525 VI_UNLOCK(vp);
3526 atomic_add_long(&deferred_inact, 1);
3527 }
3528
3529 static void
vdefer_inactive_unlocked(struct vnode * vp)3530 vdefer_inactive_unlocked(struct vnode *vp)
3531 {
3532
3533 VI_LOCK(vp);
3534 if ((vp->v_iflag & VI_OWEINACT) == 0) {
3535 vdropl(vp);
3536 return;
3537 }
3538 vdefer_inactive(vp);
3539 }
3540
3541 enum vput_op { VRELE, VPUT, VUNREF };
3542
3543 /*
3544 * Handle ->v_usecount transitioning to 0.
3545 *
3546 * By releasing the last usecount we take ownership of the hold count which
3547 * provides liveness of the vnode, meaning we have to vdrop.
3548 *
3549 * For all vnodes we may need to perform inactive processing. It requires an
3550 * exclusive lock on the vnode, while it is legal to call here with only a
3551 * shared lock (or no locks). If locking the vnode in an expected manner fails,
3552 * inactive processing gets deferred to the syncer.
3553 *
3554 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend
3555 * on the lock being held all the way until VOP_INACTIVE. This in particular
3556 * happens with UFS which adds half-constructed vnodes to the hash, where they
3557 * can be found by other code.
3558 */
3559 static void
vput_final(struct vnode * vp,enum vput_op func)3560 vput_final(struct vnode *vp, enum vput_op func)
3561 {
3562 int error;
3563 bool want_unlock;
3564
3565 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3566 VNPASS(vp->v_holdcnt > 0, vp);
3567
3568 VI_LOCK(vp);
3569
3570 /*
3571 * By the time we got here someone else might have transitioned
3572 * the count back to > 0.
3573 */
3574 if (vp->v_usecount > 0)
3575 goto out;
3576
3577 /*
3578 * If the vnode is doomed vgone already performed inactive processing
3579 * (if needed).
3580 */
3581 if (VN_IS_DOOMED(vp))
3582 goto out;
3583
3584 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0))
3585 goto out;
3586
3587 if (vp->v_iflag & VI_DOINGINACT)
3588 goto out;
3589
3590 /*
3591 * Locking operations here will drop the interlock and possibly the
3592 * vnode lock, opening a window where the vnode can get doomed all the
3593 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to
3594 * perform inactive.
3595 */
3596 vp->v_iflag |= VI_OWEINACT;
3597 want_unlock = false;
3598 error = 0;
3599 switch (func) {
3600 case VRELE:
3601 switch (VOP_ISLOCKED(vp)) {
3602 case LK_EXCLUSIVE:
3603 break;
3604 case LK_EXCLOTHER:
3605 case 0:
3606 want_unlock = true;
3607 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
3608 VI_LOCK(vp);
3609 break;
3610 default:
3611 /*
3612 * The lock has at least one sharer, but we have no way
3613 * to conclude whether this is us. Play it safe and
3614 * defer processing.
3615 */
3616 error = EAGAIN;
3617 break;
3618 }
3619 break;
3620 case VPUT:
3621 want_unlock = true;
3622 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3623 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
3624 LK_NOWAIT);
3625 VI_LOCK(vp);
3626 }
3627 break;
3628 case VUNREF:
3629 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3630 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
3631 VI_LOCK(vp);
3632 }
3633 break;
3634 }
3635 if (error == 0) {
3636 if (func == VUNREF) {
3637 VNASSERT((vp->v_vflag & VV_UNREF) == 0, vp,
3638 ("recursive vunref"));
3639 vp->v_vflag |= VV_UNREF;
3640 }
3641 for (;;) {
3642 error = vinactive(vp);
3643 if (want_unlock)
3644 VOP_UNLOCK(vp);
3645 if (error != ERELOOKUP || !want_unlock)
3646 break;
3647 VOP_LOCK(vp, LK_EXCLUSIVE);
3648 }
3649 if (func == VUNREF)
3650 vp->v_vflag &= ~VV_UNREF;
3651 vdropl(vp);
3652 } else {
3653 vdefer_inactive(vp);
3654 }
3655 return;
3656 out:
3657 if (func == VPUT)
3658 VOP_UNLOCK(vp);
3659 vdropl(vp);
3660 }
3661
3662 /*
3663 * Decrement ->v_usecount for a vnode.
3664 *
3665 * Releasing the last use count requires additional processing, see vput_final
3666 * above for details.
3667 *
3668 * Comment above each variant denotes lock state on entry and exit.
3669 */
3670
3671 /*
3672 * in: any
3673 * out: same as passed in
3674 */
3675 void
vrele(struct vnode * vp)3676 vrele(struct vnode *vp)
3677 {
3678
3679 ASSERT_VI_UNLOCKED(vp, __func__);
3680 if (!refcount_release(&vp->v_usecount))
3681 return;
3682 vput_final(vp, VRELE);
3683 }
3684
3685 /*
3686 * in: locked
3687 * out: unlocked
3688 */
3689 void
vput(struct vnode * vp)3690 vput(struct vnode *vp)
3691 {
3692
3693 ASSERT_VOP_LOCKED(vp, __func__);
3694 ASSERT_VI_UNLOCKED(vp, __func__);
3695 if (!refcount_release(&vp->v_usecount)) {
3696 VOP_UNLOCK(vp);
3697 return;
3698 }
3699 vput_final(vp, VPUT);
3700 }
3701
3702 /*
3703 * in: locked
3704 * out: locked
3705 */
3706 void
vunref(struct vnode * vp)3707 vunref(struct vnode *vp)
3708 {
3709
3710 ASSERT_VOP_LOCKED(vp, __func__);
3711 ASSERT_VI_UNLOCKED(vp, __func__);
3712 if (!refcount_release(&vp->v_usecount))
3713 return;
3714 vput_final(vp, VUNREF);
3715 }
3716
3717 void
vhold(struct vnode * vp)3718 vhold(struct vnode *vp)
3719 {
3720 int old;
3721
3722 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3723 old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3724 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3725 ("%s: wrong hold count %d", __func__, old));
3726 if (old == 0)
3727 vfs_freevnodes_dec();
3728 }
3729
3730 void
vholdnz(struct vnode * vp)3731 vholdnz(struct vnode *vp)
3732 {
3733
3734 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3735 #ifdef INVARIANTS
3736 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3737 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3738 ("%s: wrong hold count %d", __func__, old));
3739 #else
3740 atomic_add_int(&vp->v_holdcnt, 1);
3741 #endif
3742 }
3743
3744 /*
3745 * Grab a hold count unless the vnode is freed.
3746 *
3747 * Only use this routine if vfs smr is the only protection you have against
3748 * freeing the vnode.
3749 *
3750 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag
3751 * is not set. After the flag is set the vnode becomes immutable to anyone but
3752 * the thread which managed to set the flag.
3753 *
3754 * It may be tempting to replace the loop with:
3755 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3756 * if (count & VHOLD_NO_SMR) {
3757 * backpedal and error out;
3758 * }
3759 *
3760 * However, while this is more performant, it hinders debugging by eliminating
3761 * the previously mentioned invariant.
3762 */
3763 bool
vhold_smr(struct vnode * vp)3764 vhold_smr(struct vnode *vp)
3765 {
3766 int count;
3767
3768 VFS_SMR_ASSERT_ENTERED();
3769
3770 count = atomic_load_int(&vp->v_holdcnt);
3771 for (;;) {
3772 if (count & VHOLD_NO_SMR) {
3773 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3774 ("non-zero hold count with flags %d\n", count));
3775 return (false);
3776 }
3777 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3778 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3779 if (count == 0)
3780 vfs_freevnodes_dec();
3781 return (true);
3782 }
3783 }
3784 }
3785
3786 /*
3787 * Hold a free vnode for recycling.
3788 *
3789 * Note: vnode_init references this comment.
3790 *
3791 * Attempts to recycle only need the global vnode list lock and have no use for
3792 * SMR.
3793 *
3794 * However, vnodes get inserted into the global list before they get fully
3795 * initialized and stay there until UMA decides to free the memory. This in
3796 * particular means the target can be found before it becomes usable and after
3797 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to
3798 * VHOLD_NO_SMR.
3799 *
3800 * Note: the vnode may gain more references after we transition the count 0->1.
3801 */
3802 static bool
vhold_recycle_free(struct vnode * vp)3803 vhold_recycle_free(struct vnode *vp)
3804 {
3805 int count;
3806
3807 mtx_assert(&vnode_list_mtx, MA_OWNED);
3808
3809 count = atomic_load_int(&vp->v_holdcnt);
3810 for (;;) {
3811 if (count & VHOLD_NO_SMR) {
3812 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3813 ("non-zero hold count with flags %d\n", count));
3814 return (false);
3815 }
3816 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3817 if (count > 0) {
3818 return (false);
3819 }
3820 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3821 vfs_freevnodes_dec();
3822 return (true);
3823 }
3824 }
3825 }
3826
3827 static void __noinline
vdbatch_process(struct vdbatch * vd)3828 vdbatch_process(struct vdbatch *vd)
3829 {
3830 struct vnode *vp;
3831 int i;
3832
3833 mtx_assert(&vd->lock, MA_OWNED);
3834 MPASS(curthread->td_pinned > 0);
3835 MPASS(vd->index == VDBATCH_SIZE);
3836
3837 /*
3838 * Attempt to requeue the passed batch, but give up easily.
3839 *
3840 * Despite batching the mechanism is prone to transient *significant*
3841 * lock contention, where vnode_list_mtx becomes the primary bottleneck
3842 * if multiple CPUs get here (one real-world example is highly parallel
3843 * do-nothing make , which will stat *tons* of vnodes). Since it is
3844 * quasi-LRU (read: not that great even if fully honoured) provide an
3845 * option to just dodge the problem. Parties which don't like it are
3846 * welcome to implement something better.
3847 */
3848 if (vnode_can_skip_requeue) {
3849 if (!mtx_trylock(&vnode_list_mtx)) {
3850 counter_u64_add(vnode_skipped_requeues, 1);
3851 critical_enter();
3852 for (i = 0; i < VDBATCH_SIZE; i++) {
3853 vp = vd->tab[i];
3854 vd->tab[i] = NULL;
3855 MPASS(vp->v_dbatchcpu != NOCPU);
3856 vp->v_dbatchcpu = NOCPU;
3857 }
3858 vd->index = 0;
3859 critical_exit();
3860 return;
3861
3862 }
3863 /* fallthrough to locked processing */
3864 } else {
3865 mtx_lock(&vnode_list_mtx);
3866 }
3867
3868 mtx_assert(&vnode_list_mtx, MA_OWNED);
3869 critical_enter();
3870 for (i = 0; i < VDBATCH_SIZE; i++) {
3871 vp = vd->tab[i];
3872 vd->tab[i] = NULL;
3873 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
3874 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist);
3875 MPASS(vp->v_dbatchcpu != NOCPU);
3876 vp->v_dbatchcpu = NOCPU;
3877 }
3878 mtx_unlock(&vnode_list_mtx);
3879 vd->index = 0;
3880 critical_exit();
3881 }
3882
3883 static void
vdbatch_enqueue(struct vnode * vp)3884 vdbatch_enqueue(struct vnode *vp)
3885 {
3886 struct vdbatch *vd;
3887
3888 ASSERT_VI_LOCKED(vp, __func__);
3889 VNPASS(!VN_IS_DOOMED(vp), vp);
3890
3891 if (vp->v_dbatchcpu != NOCPU) {
3892 VI_UNLOCK(vp);
3893 return;
3894 }
3895
3896 sched_pin();
3897 vd = DPCPU_PTR(vd);
3898 mtx_lock(&vd->lock);
3899 MPASS(vd->index < VDBATCH_SIZE);
3900 MPASS(vd->tab[vd->index] == NULL);
3901 /*
3902 * A hack: we depend on being pinned so that we know what to put in
3903 * ->v_dbatchcpu.
3904 */
3905 vp->v_dbatchcpu = curcpu;
3906 vd->tab[vd->index] = vp;
3907 vd->index++;
3908 VI_UNLOCK(vp);
3909 if (vd->index == VDBATCH_SIZE)
3910 vdbatch_process(vd);
3911 mtx_unlock(&vd->lock);
3912 sched_unpin();
3913 }
3914
3915 /*
3916 * This routine must only be called for vnodes which are about to be
3917 * deallocated. Supporting dequeue for arbitrary vndoes would require
3918 * validating that the locked batch matches.
3919 */
3920 static void
vdbatch_dequeue(struct vnode * vp)3921 vdbatch_dequeue(struct vnode *vp)
3922 {
3923 struct vdbatch *vd;
3924 int i;
3925 short cpu;
3926
3927 VNPASS(vp->v_type == VBAD || vp->v_type == VNON, vp);
3928
3929 cpu = vp->v_dbatchcpu;
3930 if (cpu == NOCPU)
3931 return;
3932
3933 vd = DPCPU_ID_PTR(cpu, vd);
3934 mtx_lock(&vd->lock);
3935 for (i = 0; i < vd->index; i++) {
3936 if (vd->tab[i] != vp)
3937 continue;
3938 vp->v_dbatchcpu = NOCPU;
3939 vd->index--;
3940 vd->tab[i] = vd->tab[vd->index];
3941 vd->tab[vd->index] = NULL;
3942 break;
3943 }
3944 mtx_unlock(&vd->lock);
3945 /*
3946 * Either we dequeued the vnode above or the target CPU beat us to it.
3947 */
3948 MPASS(vp->v_dbatchcpu == NOCPU);
3949 }
3950
3951 /*
3952 * Drop the hold count of the vnode.
3953 *
3954 * It will only get freed if this is the last hold *and* it has been vgone'd.
3955 *
3956 * Because the vnode vm object keeps a hold reference on the vnode if
3957 * there is at least one resident non-cached page, the vnode cannot
3958 * leave the active list without the page cleanup done.
3959 */
3960 static void __noinline
vdropl_final(struct vnode * vp)3961 vdropl_final(struct vnode *vp)
3962 {
3963
3964 ASSERT_VI_LOCKED(vp, __func__);
3965 VNPASS(VN_IS_DOOMED(vp), vp);
3966 /*
3967 * Set the VHOLD_NO_SMR flag.
3968 *
3969 * We may be racing against vhold_smr. If they win we can just pretend
3970 * we never got this far, they will vdrop later.
3971 */
3972 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) {
3973 vfs_freevnodes_inc();
3974 VI_UNLOCK(vp);
3975 /*
3976 * We lost the aforementioned race. Any subsequent access is
3977 * invalid as they might have managed to vdropl on their own.
3978 */
3979 return;
3980 }
3981 /*
3982 * Don't bump freevnodes as this one is going away.
3983 */
3984 freevnode(vp);
3985 }
3986
3987 void
vdrop(struct vnode * vp)3988 vdrop(struct vnode *vp)
3989 {
3990
3991 ASSERT_VI_UNLOCKED(vp, __func__);
3992 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3993 if (refcount_release_if_not_last(&vp->v_holdcnt))
3994 return;
3995 VI_LOCK(vp);
3996 vdropl(vp);
3997 }
3998
3999 static __always_inline void
vdropl_impl(struct vnode * vp,bool enqueue)4000 vdropl_impl(struct vnode *vp, bool enqueue)
4001 {
4002
4003 ASSERT_VI_LOCKED(vp, __func__);
4004 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4005 if (!refcount_release(&vp->v_holdcnt)) {
4006 VI_UNLOCK(vp);
4007 return;
4008 }
4009 VNPASS((vp->v_iflag & VI_OWEINACT) == 0, vp);
4010 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
4011 if (VN_IS_DOOMED(vp)) {
4012 vdropl_final(vp);
4013 return;
4014 }
4015
4016 vfs_freevnodes_inc();
4017 if (vp->v_mflag & VMP_LAZYLIST) {
4018 vunlazy(vp);
4019 }
4020
4021 if (!enqueue) {
4022 VI_UNLOCK(vp);
4023 return;
4024 }
4025
4026 /*
4027 * Also unlocks the interlock. We can't assert on it as we
4028 * released our hold and by now the vnode might have been
4029 * freed.
4030 */
4031 vdbatch_enqueue(vp);
4032 }
4033
4034 void
vdropl(struct vnode * vp)4035 vdropl(struct vnode *vp)
4036 {
4037
4038 vdropl_impl(vp, true);
4039 }
4040
4041 /*
4042 * vdrop a vnode when recycling
4043 *
4044 * This is a special case routine only to be used when recycling, differs from
4045 * regular vdrop by not requeieing the vnode on LRU.
4046 *
4047 * Consider a case where vtryrecycle continuously fails with all vnodes (due to
4048 * e.g., frozen writes on the filesystem), filling the batch and causing it to
4049 * be requeued. Then vnlru will end up revisiting the same vnodes. This is a
4050 * loop which can last for as long as writes are frozen.
4051 */
4052 static void
vdropl_recycle(struct vnode * vp)4053 vdropl_recycle(struct vnode *vp)
4054 {
4055
4056 vdropl_impl(vp, false);
4057 }
4058
4059 static void
vdrop_recycle(struct vnode * vp)4060 vdrop_recycle(struct vnode *vp)
4061 {
4062
4063 VI_LOCK(vp);
4064 vdropl_recycle(vp);
4065 }
4066
4067 /*
4068 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
4069 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
4070 */
4071 static int
vinactivef(struct vnode * vp)4072 vinactivef(struct vnode *vp)
4073 {
4074 int error;
4075
4076 ASSERT_VOP_ELOCKED(vp, "vinactive");
4077 ASSERT_VI_LOCKED(vp, "vinactive");
4078 VNPASS((vp->v_iflag & VI_DOINGINACT) == 0, vp);
4079 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4080 vp->v_iflag |= VI_DOINGINACT;
4081 vp->v_iflag &= ~VI_OWEINACT;
4082 VI_UNLOCK(vp);
4083
4084 /*
4085 * Before moving off the active list, we must be sure that any
4086 * modified pages are converted into the vnode's dirty
4087 * buffers, since these will no longer be checked once the
4088 * vnode is on the inactive list.
4089 *
4090 * The write-out of the dirty pages is asynchronous. At the
4091 * point that VOP_INACTIVE() is called, there could still be
4092 * pending I/O and dirty pages in the object.
4093 */
4094 if ((vp->v_vflag & VV_NOSYNC) == 0)
4095 vnode_pager_clean_async(vp);
4096
4097 error = VOP_INACTIVE(vp);
4098 VI_LOCK(vp);
4099 VNPASS(vp->v_iflag & VI_DOINGINACT, vp);
4100 vp->v_iflag &= ~VI_DOINGINACT;
4101 return (error);
4102 }
4103
4104 int
vinactive(struct vnode * vp)4105 vinactive(struct vnode *vp)
4106 {
4107
4108 ASSERT_VOP_ELOCKED(vp, "vinactive");
4109 ASSERT_VI_LOCKED(vp, "vinactive");
4110 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4111
4112 if ((vp->v_iflag & VI_OWEINACT) == 0)
4113 return (0);
4114 if (vp->v_iflag & VI_DOINGINACT)
4115 return (0);
4116 if (vp->v_usecount > 0) {
4117 vp->v_iflag &= ~VI_OWEINACT;
4118 return (0);
4119 }
4120 return (vinactivef(vp));
4121 }
4122
4123 /*
4124 * Remove any vnodes in the vnode table belonging to mount point mp.
4125 *
4126 * If FORCECLOSE is not specified, there should not be any active ones,
4127 * return error if any are found (nb: this is a user error, not a
4128 * system error). If FORCECLOSE is specified, detach any active vnodes
4129 * that are found.
4130 *
4131 * If WRITECLOSE is set, only flush out regular file vnodes open for
4132 * writing.
4133 *
4134 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
4135 *
4136 * `rootrefs' specifies the base reference count for the root vnode
4137 * of this filesystem. The root vnode is considered busy if its
4138 * v_usecount exceeds this value. On a successful return, vflush(, td)
4139 * will call vrele() on the root vnode exactly rootrefs times.
4140 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
4141 * be zero.
4142 */
4143 #ifdef DIAGNOSTIC
4144 static int busyprt = 0; /* print out busy vnodes */
4145 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
4146 #endif
4147
4148 int
vflush(struct mount * mp,int rootrefs,int flags,struct thread * td)4149 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
4150 {
4151 struct vnode *vp, *mvp, *rootvp = NULL;
4152 struct vattr vattr;
4153 int busy = 0, error;
4154
4155 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
4156 rootrefs, flags);
4157 if (rootrefs > 0) {
4158 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
4159 ("vflush: bad args"));
4160 /*
4161 * Get the filesystem root vnode. We can vput() it
4162 * immediately, since with rootrefs > 0, it won't go away.
4163 */
4164 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
4165 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
4166 __func__, error);
4167 return (error);
4168 }
4169 vput(rootvp);
4170 }
4171 loop:
4172 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
4173 vholdl(vp);
4174 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
4175 if (error) {
4176 vdrop(vp);
4177 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4178 goto loop;
4179 }
4180 /*
4181 * Skip over a vnodes marked VV_SYSTEM.
4182 */
4183 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
4184 VOP_UNLOCK(vp);
4185 vdrop(vp);
4186 continue;
4187 }
4188 /*
4189 * If WRITECLOSE is set, flush out unlinked but still open
4190 * files (even if open only for reading) and regular file
4191 * vnodes open for writing.
4192 */
4193 if (flags & WRITECLOSE) {
4194 vnode_pager_clean_async(vp);
4195 do {
4196 error = VOP_FSYNC(vp, MNT_WAIT, td);
4197 } while (error == ERELOOKUP);
4198 if (error != 0) {
4199 VOP_UNLOCK(vp);
4200 vdrop(vp);
4201 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4202 return (error);
4203 }
4204 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4205 VI_LOCK(vp);
4206
4207 if ((vp->v_type == VNON ||
4208 (error == 0 && vattr.va_nlink > 0)) &&
4209 (vp->v_writecount <= 0 || vp->v_type != VREG)) {
4210 VOP_UNLOCK(vp);
4211 vdropl(vp);
4212 continue;
4213 }
4214 } else
4215 VI_LOCK(vp);
4216 /*
4217 * With v_usecount == 0, all we need to do is clear out the
4218 * vnode data structures and we are done.
4219 *
4220 * If FORCECLOSE is set, forcibly close the vnode.
4221 */
4222 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
4223 vgonel(vp);
4224 } else {
4225 busy++;
4226 #ifdef DIAGNOSTIC
4227 if (busyprt)
4228 vn_printf(vp, "vflush: busy vnode ");
4229 #endif
4230 }
4231 VOP_UNLOCK(vp);
4232 vdropl(vp);
4233 }
4234 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
4235 /*
4236 * If just the root vnode is busy, and if its refcount
4237 * is equal to `rootrefs', then go ahead and kill it.
4238 */
4239 VI_LOCK(rootvp);
4240 KASSERT(busy > 0, ("vflush: not busy"));
4241 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
4242 ("vflush: usecount %d < rootrefs %d",
4243 rootvp->v_usecount, rootrefs));
4244 if (busy == 1 && rootvp->v_usecount == rootrefs) {
4245 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
4246 vgone(rootvp);
4247 VOP_UNLOCK(rootvp);
4248 busy = 0;
4249 } else
4250 VI_UNLOCK(rootvp);
4251 }
4252 if (busy) {
4253 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
4254 busy);
4255 return (EBUSY);
4256 }
4257 for (; rootrefs > 0; rootrefs--)
4258 vrele(rootvp);
4259 return (0);
4260 }
4261
4262 /*
4263 * Recycle an unused vnode.
4264 */
4265 int
vrecycle(struct vnode * vp)4266 vrecycle(struct vnode *vp)
4267 {
4268 int recycled;
4269
4270 VI_LOCK(vp);
4271 recycled = vrecyclel(vp);
4272 VI_UNLOCK(vp);
4273 return (recycled);
4274 }
4275
4276 /*
4277 * vrecycle, with the vp interlock held.
4278 */
4279 int
vrecyclel(struct vnode * vp)4280 vrecyclel(struct vnode *vp)
4281 {
4282 int recycled;
4283
4284 ASSERT_VOP_ELOCKED(vp, __func__);
4285 ASSERT_VI_LOCKED(vp, __func__);
4286 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4287 recycled = 0;
4288 if (vp->v_usecount == 0) {
4289 recycled = 1;
4290 vgonel(vp);
4291 }
4292 return (recycled);
4293 }
4294
4295 /*
4296 * Eliminate all activity associated with a vnode
4297 * in preparation for reuse.
4298 */
4299 void
vgone(struct vnode * vp)4300 vgone(struct vnode *vp)
4301 {
4302 VI_LOCK(vp);
4303 vgonel(vp);
4304 VI_UNLOCK(vp);
4305 }
4306
4307 /*
4308 * Notify upper mounts about reclaimed or unlinked vnode.
4309 */
4310 void
vfs_notify_upper(struct vnode * vp,enum vfs_notify_upper_type event)4311 vfs_notify_upper(struct vnode *vp, enum vfs_notify_upper_type event)
4312 {
4313 struct mount *mp;
4314 struct mount_upper_node *ump;
4315
4316 mp = atomic_load_ptr(&vp->v_mount);
4317 if (mp == NULL)
4318 return;
4319 if (TAILQ_EMPTY(&mp->mnt_notify))
4320 return;
4321
4322 MNT_ILOCK(mp);
4323 mp->mnt_upper_pending++;
4324 KASSERT(mp->mnt_upper_pending > 0,
4325 ("%s: mnt_upper_pending %d", __func__, mp->mnt_upper_pending));
4326 TAILQ_FOREACH(ump, &mp->mnt_notify, mnt_upper_link) {
4327 MNT_IUNLOCK(mp);
4328 switch (event) {
4329 case VFS_NOTIFY_UPPER_RECLAIM:
4330 VFS_RECLAIM_LOWERVP(ump->mp, vp);
4331 break;
4332 case VFS_NOTIFY_UPPER_UNLINK:
4333 VFS_UNLINK_LOWERVP(ump->mp, vp);
4334 break;
4335 }
4336 MNT_ILOCK(mp);
4337 }
4338 mp->mnt_upper_pending--;
4339 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 &&
4340 mp->mnt_upper_pending == 0) {
4341 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER;
4342 wakeup(&mp->mnt_uppers);
4343 }
4344 MNT_IUNLOCK(mp);
4345 }
4346
4347 /*
4348 * vgone, with the vp interlock held.
4349 */
4350 static void
vgonel(struct vnode * vp)4351 vgonel(struct vnode *vp)
4352 {
4353 struct thread *td;
4354 struct mount *mp;
4355 vm_object_t object;
4356 bool active, doinginact, oweinact;
4357
4358 ASSERT_VOP_ELOCKED(vp, "vgonel");
4359 ASSERT_VI_LOCKED(vp, "vgonel");
4360 VNASSERT(vp->v_holdcnt, vp,
4361 ("vgonel: vp %p has no reference.", vp));
4362 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4363 td = curthread;
4364
4365 /*
4366 * Don't vgonel if we're already doomed.
4367 */
4368 if (VN_IS_DOOMED(vp)) {
4369 VNPASS(vn_get_state(vp) == VSTATE_DESTROYING || \
4370 vn_get_state(vp) == VSTATE_DEAD, vp);
4371 return;
4372 }
4373 /*
4374 * Paired with freevnode.
4375 */
4376 vn_seqc_write_begin_locked(vp);
4377 vunlazy_gone(vp);
4378 vn_irflag_set_locked(vp, VIRF_DOOMED);
4379 vn_set_state(vp, VSTATE_DESTROYING);
4380
4381 /*
4382 * Check to see if the vnode is in use. If so, we have to
4383 * call VOP_CLOSE() and VOP_INACTIVE().
4384 *
4385 * It could be that VOP_INACTIVE() requested reclamation, in
4386 * which case we should avoid recursion, so check
4387 * VI_DOINGINACT. This is not precise but good enough.
4388 */
4389 active = vp->v_usecount > 0;
4390 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4391 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0;
4392
4393 /*
4394 * If we need to do inactive VI_OWEINACT will be set.
4395 */
4396 if (vp->v_iflag & VI_DEFINACT) {
4397 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count"));
4398 vp->v_iflag &= ~VI_DEFINACT;
4399 vdropl(vp);
4400 } else {
4401 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count"));
4402 VI_UNLOCK(vp);
4403 }
4404 cache_purge_vgone(vp);
4405 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
4406
4407 /*
4408 * If purging an active vnode, it must be closed and
4409 * deactivated before being reclaimed.
4410 */
4411 if (active)
4412 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
4413 if (!doinginact) {
4414 do {
4415 if (oweinact || active) {
4416 VI_LOCK(vp);
4417 vinactivef(vp);
4418 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4419 VI_UNLOCK(vp);
4420 }
4421 } while (oweinact);
4422 }
4423 if (vp->v_type == VSOCK)
4424 vfs_unp_reclaim(vp);
4425
4426 /*
4427 * Clean out any buffers associated with the vnode.
4428 * If the flush fails, just toss the buffers.
4429 */
4430 mp = NULL;
4431 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
4432 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
4433 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
4434 while (vinvalbuf(vp, 0, 0, 0) != 0)
4435 ;
4436 }
4437
4438 BO_LOCK(&vp->v_bufobj);
4439 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
4440 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
4441 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
4442 vp->v_bufobj.bo_clean.bv_cnt == 0,
4443 ("vp %p bufobj not invalidated", vp));
4444
4445 /*
4446 * For VMIO bufobj, BO_DEAD is set later, or in
4447 * vm_object_terminate() after the object's page queue is
4448 * flushed.
4449 */
4450 object = vp->v_bufobj.bo_object;
4451 if (object == NULL)
4452 vp->v_bufobj.bo_flag |= BO_DEAD;
4453 BO_UNLOCK(&vp->v_bufobj);
4454
4455 /*
4456 * Handle the VM part. Tmpfs handles v_object on its own (the
4457 * OBJT_VNODE check). Nullfs or other bypassing filesystems
4458 * should not touch the object borrowed from the lower vnode
4459 * (the handle check).
4460 */
4461 if (object != NULL && object->type == OBJT_VNODE &&
4462 object->handle == vp)
4463 vnode_destroy_vobject(vp);
4464
4465 /*
4466 * Reclaim the vnode.
4467 */
4468 if (VOP_RECLAIM(vp))
4469 panic("vgone: cannot reclaim");
4470 if (mp != NULL)
4471 vn_finished_secondary_write(mp);
4472 VNASSERT(vp->v_object == NULL, vp,
4473 ("vop_reclaim left v_object vp=%p", vp));
4474 /*
4475 * Clear the advisory locks and wake up waiting threads.
4476 */
4477 if (vp->v_lockf != NULL) {
4478 (void)VOP_ADVLOCKPURGE(vp);
4479 vp->v_lockf = NULL;
4480 }
4481 /*
4482 * Delete from old mount point vnode list.
4483 */
4484 if (vp->v_mount == NULL) {
4485 VI_LOCK(vp);
4486 } else {
4487 delmntque(vp);
4488 ASSERT_VI_LOCKED(vp, "vgonel 2");
4489 }
4490 /*
4491 * Done with purge, reset to the standard lock and invalidate
4492 * the vnode.
4493 */
4494 vp->v_vnlock = &vp->v_lock;
4495 vp->v_op = &dead_vnodeops;
4496 vp->v_type = VBAD;
4497 vn_set_state(vp, VSTATE_DEAD);
4498 }
4499
4500 /*
4501 * Print out a description of a vnode.
4502 */
4503 static const char *const vtypename[] = {
4504 [VNON] = "VNON",
4505 [VREG] = "VREG",
4506 [VDIR] = "VDIR",
4507 [VBLK] = "VBLK",
4508 [VCHR] = "VCHR",
4509 [VLNK] = "VLNK",
4510 [VSOCK] = "VSOCK",
4511 [VFIFO] = "VFIFO",
4512 [VBAD] = "VBAD",
4513 [VMARKER] = "VMARKER",
4514 };
4515 _Static_assert(nitems(vtypename) == VLASTTYPE + 1,
4516 "vnode type name not added to vtypename");
4517
4518 static const char *const vstatename[] = {
4519 [VSTATE_UNINITIALIZED] = "VSTATE_UNINITIALIZED",
4520 [VSTATE_CONSTRUCTED] = "VSTATE_CONSTRUCTED",
4521 [VSTATE_DESTROYING] = "VSTATE_DESTROYING",
4522 [VSTATE_DEAD] = "VSTATE_DEAD",
4523 };
4524 _Static_assert(nitems(vstatename) == VLASTSTATE + 1,
4525 "vnode state name not added to vstatename");
4526
4527 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0,
4528 "new hold count flag not added to vn_printf");
4529
4530 void
vn_printf(struct vnode * vp,const char * fmt,...)4531 vn_printf(struct vnode *vp, const char *fmt, ...)
4532 {
4533 va_list ap;
4534 char buf[256], buf2[16];
4535 u_long flags;
4536 u_int holdcnt;
4537 short irflag;
4538
4539 va_start(ap, fmt);
4540 vprintf(fmt, ap);
4541 va_end(ap);
4542 printf("%p: ", (void *)vp);
4543 printf("type %s state %s op %p\n", vtypename[vp->v_type],
4544 vstatename[vp->v_state], vp->v_op);
4545 holdcnt = atomic_load_int(&vp->v_holdcnt);
4546 printf(" usecount %d, writecount %d, refcount %d seqc users %d",
4547 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS,
4548 vp->v_seqc_users);
4549 switch (vp->v_type) {
4550 case VDIR:
4551 printf(" mountedhere %p\n", vp->v_mountedhere);
4552 break;
4553 case VCHR:
4554 printf(" rdev %p\n", vp->v_rdev);
4555 break;
4556 case VSOCK:
4557 printf(" socket %p\n", vp->v_unpcb);
4558 break;
4559 case VFIFO:
4560 printf(" fifoinfo %p\n", vp->v_fifoinfo);
4561 break;
4562 default:
4563 printf("\n");
4564 break;
4565 }
4566 buf[0] = '\0';
4567 buf[1] = '\0';
4568 if (holdcnt & VHOLD_NO_SMR)
4569 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf));
4570 printf(" hold count flags (%s)\n", buf + 1);
4571
4572 buf[0] = '\0';
4573 buf[1] = '\0';
4574 irflag = vn_irflag_read(vp);
4575 if (irflag & VIRF_DOOMED)
4576 strlcat(buf, "|VIRF_DOOMED", sizeof(buf));
4577 if (irflag & VIRF_PGREAD)
4578 strlcat(buf, "|VIRF_PGREAD", sizeof(buf));
4579 if (irflag & VIRF_MOUNTPOINT)
4580 strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf));
4581 if (irflag & VIRF_TEXT_REF)
4582 strlcat(buf, "|VIRF_TEXT_REF", sizeof(buf));
4583 flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT | VIRF_TEXT_REF);
4584 if (flags != 0) {
4585 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags);
4586 strlcat(buf, buf2, sizeof(buf));
4587 }
4588 if (vp->v_vflag & VV_ROOT)
4589 strlcat(buf, "|VV_ROOT", sizeof(buf));
4590 if (vp->v_vflag & VV_ISTTY)
4591 strlcat(buf, "|VV_ISTTY", sizeof(buf));
4592 if (vp->v_vflag & VV_NOSYNC)
4593 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
4594 if (vp->v_vflag & VV_ETERNALDEV)
4595 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
4596 if (vp->v_vflag & VV_CACHEDLABEL)
4597 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
4598 if (vp->v_vflag & VV_VMSIZEVNLOCK)
4599 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf));
4600 if (vp->v_vflag & VV_COPYONWRITE)
4601 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
4602 if (vp->v_vflag & VV_SYSTEM)
4603 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
4604 if (vp->v_vflag & VV_PROCDEP)
4605 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
4606 if (vp->v_vflag & VV_DELETED)
4607 strlcat(buf, "|VV_DELETED", sizeof(buf));
4608 if (vp->v_vflag & VV_MD)
4609 strlcat(buf, "|VV_MD", sizeof(buf));
4610 if (vp->v_vflag & VV_FORCEINSMQ)
4611 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
4612 if (vp->v_vflag & VV_READLINK)
4613 strlcat(buf, "|VV_READLINK", sizeof(buf));
4614 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
4615 VV_CACHEDLABEL | VV_VMSIZEVNLOCK | VV_COPYONWRITE | VV_SYSTEM |
4616 VV_PROCDEP | VV_DELETED | VV_MD | VV_FORCEINSMQ | VV_READLINK);
4617 if (flags != 0) {
4618 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
4619 strlcat(buf, buf2, sizeof(buf));
4620 }
4621 if (vp->v_iflag & VI_MOUNT)
4622 strlcat(buf, "|VI_MOUNT", sizeof(buf));
4623 if (vp->v_iflag & VI_DOINGINACT)
4624 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
4625 if (vp->v_iflag & VI_OWEINACT)
4626 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
4627 if (vp->v_iflag & VI_DEFINACT)
4628 strlcat(buf, "|VI_DEFINACT", sizeof(buf));
4629 if (vp->v_iflag & VI_FOPENING)
4630 strlcat(buf, "|VI_FOPENING", sizeof(buf));
4631 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOINGINACT |
4632 VI_OWEINACT | VI_DEFINACT | VI_FOPENING);
4633 if (flags != 0) {
4634 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
4635 strlcat(buf, buf2, sizeof(buf));
4636 }
4637 if (vp->v_mflag & VMP_LAZYLIST)
4638 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf));
4639 flags = vp->v_mflag & ~(VMP_LAZYLIST);
4640 if (flags != 0) {
4641 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags);
4642 strlcat(buf, buf2, sizeof(buf));
4643 }
4644 printf(" flags (%s)", buf + 1);
4645 if (mtx_owned(VI_MTX(vp)))
4646 printf(" VI_LOCKed");
4647 printf("\n");
4648 if (vp->v_object != NULL)
4649 printf(" v_object %p ref %d pages %d "
4650 "cleanbuf %d dirtybuf %d\n",
4651 vp->v_object, vp->v_object->ref_count,
4652 vp->v_object->resident_page_count,
4653 vp->v_bufobj.bo_clean.bv_cnt,
4654 vp->v_bufobj.bo_dirty.bv_cnt);
4655 printf(" ");
4656 lockmgr_printinfo(vp->v_vnlock);
4657 if (vp->v_data != NULL)
4658 VOP_PRINT(vp);
4659 }
4660
4661 #ifdef DDB
4662 /*
4663 * List all of the locked vnodes in the system.
4664 * Called when debugging the kernel.
4665 */
DB_SHOW_COMMAND_FLAGS(lockedvnods,lockedvnodes,DB_CMD_MEMSAFE)4666 DB_SHOW_COMMAND_FLAGS(lockedvnods, lockedvnodes, DB_CMD_MEMSAFE)
4667 {
4668 struct mount *mp;
4669 struct vnode *vp;
4670
4671 /*
4672 * Note: because this is DDB, we can't obey the locking semantics
4673 * for these structures, which means we could catch an inconsistent
4674 * state and dereference a nasty pointer. Not much to be done
4675 * about that.
4676 */
4677 db_printf("Locked vnodes\n");
4678 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4679 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4680 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
4681 vn_printf(vp, "vnode ");
4682 }
4683 }
4684 }
4685
4686 /*
4687 * Show details about the given vnode.
4688 */
DB_SHOW_COMMAND(vnode,db_show_vnode)4689 DB_SHOW_COMMAND(vnode, db_show_vnode)
4690 {
4691 struct vnode *vp;
4692
4693 if (!have_addr)
4694 return;
4695 vp = (struct vnode *)addr;
4696 vn_printf(vp, "vnode ");
4697 }
4698
4699 /*
4700 * Show details about the given mount point.
4701 */
DB_SHOW_COMMAND(mount,db_show_mount)4702 DB_SHOW_COMMAND(mount, db_show_mount)
4703 {
4704 struct mount *mp;
4705 struct vfsopt *opt;
4706 struct statfs *sp;
4707 struct vnode *vp;
4708 char buf[512];
4709 uint64_t mflags;
4710 u_int flags;
4711
4712 if (!have_addr) {
4713 /* No address given, print short info about all mount points. */
4714 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4715 db_printf("%p %s on %s (%s)\n", mp,
4716 mp->mnt_stat.f_mntfromname,
4717 mp->mnt_stat.f_mntonname,
4718 mp->mnt_stat.f_fstypename);
4719 if (db_pager_quit)
4720 break;
4721 }
4722 db_printf("\nMore info: show mount <addr>\n");
4723 return;
4724 }
4725
4726 mp = (struct mount *)addr;
4727 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
4728 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
4729
4730 buf[0] = '\0';
4731 mflags = mp->mnt_flag;
4732 #define MNT_FLAG(flag) do { \
4733 if (mflags & (flag)) { \
4734 if (buf[0] != '\0') \
4735 strlcat(buf, ", ", sizeof(buf)); \
4736 strlcat(buf, (#flag) + 4, sizeof(buf)); \
4737 mflags &= ~(flag); \
4738 } \
4739 } while (0)
4740 MNT_FLAG(MNT_RDONLY);
4741 MNT_FLAG(MNT_SYNCHRONOUS);
4742 MNT_FLAG(MNT_NOEXEC);
4743 MNT_FLAG(MNT_NOSUID);
4744 MNT_FLAG(MNT_NFS4ACLS);
4745 MNT_FLAG(MNT_UNION);
4746 MNT_FLAG(MNT_ASYNC);
4747 MNT_FLAG(MNT_SUIDDIR);
4748 MNT_FLAG(MNT_SOFTDEP);
4749 MNT_FLAG(MNT_NOSYMFOLLOW);
4750 MNT_FLAG(MNT_GJOURNAL);
4751 MNT_FLAG(MNT_MULTILABEL);
4752 MNT_FLAG(MNT_ACLS);
4753 MNT_FLAG(MNT_NOATIME);
4754 MNT_FLAG(MNT_NOCLUSTERR);
4755 MNT_FLAG(MNT_NOCLUSTERW);
4756 MNT_FLAG(MNT_SUJ);
4757 MNT_FLAG(MNT_EXRDONLY);
4758 MNT_FLAG(MNT_EXPORTED);
4759 MNT_FLAG(MNT_DEFEXPORTED);
4760 MNT_FLAG(MNT_EXPORTANON);
4761 MNT_FLAG(MNT_EXKERB);
4762 MNT_FLAG(MNT_EXPUBLIC);
4763 MNT_FLAG(MNT_LOCAL);
4764 MNT_FLAG(MNT_QUOTA);
4765 MNT_FLAG(MNT_ROOTFS);
4766 MNT_FLAG(MNT_USER);
4767 MNT_FLAG(MNT_IGNORE);
4768 MNT_FLAG(MNT_UPDATE);
4769 MNT_FLAG(MNT_DELEXPORT);
4770 MNT_FLAG(MNT_RELOAD);
4771 MNT_FLAG(MNT_FORCE);
4772 MNT_FLAG(MNT_SNAPSHOT);
4773 MNT_FLAG(MNT_BYFSID);
4774 #undef MNT_FLAG
4775 if (mflags != 0) {
4776 if (buf[0] != '\0')
4777 strlcat(buf, ", ", sizeof(buf));
4778 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4779 "0x%016jx", mflags);
4780 }
4781 db_printf(" mnt_flag = %s\n", buf);
4782
4783 buf[0] = '\0';
4784 flags = mp->mnt_kern_flag;
4785 #define MNT_KERN_FLAG(flag) do { \
4786 if (flags & (flag)) { \
4787 if (buf[0] != '\0') \
4788 strlcat(buf, ", ", sizeof(buf)); \
4789 strlcat(buf, (#flag) + 5, sizeof(buf)); \
4790 flags &= ~(flag); \
4791 } \
4792 } while (0)
4793 MNT_KERN_FLAG(MNTK_UNMOUNTF);
4794 MNT_KERN_FLAG(MNTK_ASYNC);
4795 MNT_KERN_FLAG(MNTK_SOFTDEP);
4796 MNT_KERN_FLAG(MNTK_NOMSYNC);
4797 MNT_KERN_FLAG(MNTK_DRAINING);
4798 MNT_KERN_FLAG(MNTK_REFEXPIRE);
4799 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
4800 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
4801 MNT_KERN_FLAG(MNTK_NO_IOPF);
4802 MNT_KERN_FLAG(MNTK_RECURSE);
4803 MNT_KERN_FLAG(MNTK_UPPER_WAITER);
4804 MNT_KERN_FLAG(MNTK_UNLOCKED_INSMNTQUE);
4805 MNT_KERN_FLAG(MNTK_USES_BCACHE);
4806 MNT_KERN_FLAG(MNTK_VMSETSIZE_BUG);
4807 MNT_KERN_FLAG(MNTK_FPLOOKUP);
4808 MNT_KERN_FLAG(MNTK_TASKQUEUE_WAITER);
4809 MNT_KERN_FLAG(MNTK_NOASYNC);
4810 MNT_KERN_FLAG(MNTK_UNMOUNT);
4811 MNT_KERN_FLAG(MNTK_MWAIT);
4812 MNT_KERN_FLAG(MNTK_SUSPEND);
4813 MNT_KERN_FLAG(MNTK_SUSPEND2);
4814 MNT_KERN_FLAG(MNTK_SUSPENDED);
4815 MNT_KERN_FLAG(MNTK_NULL_NOCACHE);
4816 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
4817 #undef MNT_KERN_FLAG
4818 if (flags != 0) {
4819 if (buf[0] != '\0')
4820 strlcat(buf, ", ", sizeof(buf));
4821 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4822 "0x%08x", flags);
4823 }
4824 db_printf(" mnt_kern_flag = %s\n", buf);
4825
4826 db_printf(" mnt_opt = ");
4827 opt = TAILQ_FIRST(mp->mnt_opt);
4828 if (opt != NULL) {
4829 db_printf("%s", opt->name);
4830 opt = TAILQ_NEXT(opt, link);
4831 while (opt != NULL) {
4832 db_printf(", %s", opt->name);
4833 opt = TAILQ_NEXT(opt, link);
4834 }
4835 }
4836 db_printf("\n");
4837
4838 sp = &mp->mnt_stat;
4839 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
4840 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
4841 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
4842 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
4843 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
4844 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
4845 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
4846 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
4847 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
4848 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
4849 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
4850 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
4851
4852 db_printf(" mnt_cred = { uid=%u ruid=%u",
4853 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
4854 if (jailed(mp->mnt_cred))
4855 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
4856 db_printf(" }\n");
4857 db_printf(" mnt_ref = %d (with %d in the struct)\n",
4858 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref);
4859 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
4860 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
4861 db_printf(" mnt_lazyvnodelistsize = %d\n",
4862 mp->mnt_lazyvnodelistsize);
4863 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n",
4864 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount);
4865 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
4866 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
4867 db_printf(" mnt_lockref = %d (with %d in the struct)\n",
4868 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref);
4869 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
4870 db_printf(" mnt_secondary_accwrites = %d\n",
4871 mp->mnt_secondary_accwrites);
4872 db_printf(" mnt_gjprovider = %s\n",
4873 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
4874 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops);
4875
4876 db_printf("\n\nList of active vnodes\n");
4877 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4878 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) {
4879 vn_printf(vp, "vnode ");
4880 if (db_pager_quit)
4881 break;
4882 }
4883 }
4884 db_printf("\n\nList of inactive vnodes\n");
4885 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4886 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) {
4887 vn_printf(vp, "vnode ");
4888 if (db_pager_quit)
4889 break;
4890 }
4891 }
4892 }
4893 #endif /* DDB */
4894
4895 /*
4896 * Fill in a struct xvfsconf based on a struct vfsconf.
4897 */
4898 static int
vfsconf2x(struct sysctl_req * req,struct vfsconf * vfsp)4899 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
4900 {
4901 struct xvfsconf xvfsp;
4902
4903 bzero(&xvfsp, sizeof(xvfsp));
4904 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4905 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4906 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4907 xvfsp.vfc_flags = vfsp->vfc_flags;
4908 /*
4909 * These are unused in userland, we keep them
4910 * to not break binary compatibility.
4911 */
4912 xvfsp.vfc_vfsops = NULL;
4913 xvfsp.vfc_next = NULL;
4914 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4915 }
4916
4917 #ifdef COMPAT_FREEBSD32
4918 struct xvfsconf32 {
4919 uint32_t vfc_vfsops;
4920 char vfc_name[MFSNAMELEN];
4921 int32_t vfc_typenum;
4922 int32_t vfc_refcount;
4923 int32_t vfc_flags;
4924 uint32_t vfc_next;
4925 };
4926
4927 static int
vfsconf2x32(struct sysctl_req * req,struct vfsconf * vfsp)4928 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
4929 {
4930 struct xvfsconf32 xvfsp;
4931
4932 bzero(&xvfsp, sizeof(xvfsp));
4933 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4934 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4935 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4936 xvfsp.vfc_flags = vfsp->vfc_flags;
4937 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4938 }
4939 #endif
4940
4941 /*
4942 * Top level filesystem related information gathering.
4943 */
4944 static int
sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)4945 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
4946 {
4947 struct vfsconf *vfsp;
4948 int error;
4949
4950 error = 0;
4951 vfsconf_slock();
4952 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4953 #ifdef COMPAT_FREEBSD32
4954 if (req->flags & SCTL_MASK32)
4955 error = vfsconf2x32(req, vfsp);
4956 else
4957 #endif
4958 error = vfsconf2x(req, vfsp);
4959 if (error)
4960 break;
4961 }
4962 vfsconf_sunlock();
4963 return (error);
4964 }
4965
4966 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
4967 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
4968 "S,xvfsconf", "List of all configured filesystems");
4969
4970 #ifndef BURN_BRIDGES
4971 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
4972
4973 static int
vfs_sysctl(SYSCTL_HANDLER_ARGS)4974 vfs_sysctl(SYSCTL_HANDLER_ARGS)
4975 {
4976 int *name = (int *)arg1 - 1; /* XXX */
4977 u_int namelen = arg2 + 1; /* XXX */
4978 struct vfsconf *vfsp;
4979
4980 log(LOG_WARNING, "userland calling deprecated sysctl, "
4981 "please rebuild world\n");
4982
4983 #if 1 || defined(COMPAT_PRELITE2)
4984 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
4985 if (namelen == 1)
4986 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
4987 #endif
4988
4989 switch (name[1]) {
4990 case VFS_MAXTYPENUM:
4991 if (namelen != 2)
4992 return (ENOTDIR);
4993 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
4994 case VFS_CONF:
4995 if (namelen != 3)
4996 return (ENOTDIR); /* overloaded */
4997 vfsconf_slock();
4998 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4999 if (vfsp->vfc_typenum == name[2])
5000 break;
5001 }
5002 vfsconf_sunlock();
5003 if (vfsp == NULL)
5004 return (EOPNOTSUPP);
5005 #ifdef COMPAT_FREEBSD32
5006 if (req->flags & SCTL_MASK32)
5007 return (vfsconf2x32(req, vfsp));
5008 else
5009 #endif
5010 return (vfsconf2x(req, vfsp));
5011 }
5012 return (EOPNOTSUPP);
5013 }
5014
5015 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
5016 CTLFLAG_MPSAFE, vfs_sysctl,
5017 "Generic filesystem");
5018
5019 #if 1 || defined(COMPAT_PRELITE2)
5020
5021 static int
sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)5022 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
5023 {
5024 int error;
5025 struct vfsconf *vfsp;
5026 struct ovfsconf ovfs;
5027
5028 vfsconf_slock();
5029 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
5030 bzero(&ovfs, sizeof(ovfs));
5031 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
5032 strcpy(ovfs.vfc_name, vfsp->vfc_name);
5033 ovfs.vfc_index = vfsp->vfc_typenum;
5034 ovfs.vfc_refcount = vfsp->vfc_refcount;
5035 ovfs.vfc_flags = vfsp->vfc_flags;
5036 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
5037 if (error != 0) {
5038 vfsconf_sunlock();
5039 return (error);
5040 }
5041 }
5042 vfsconf_sunlock();
5043 return (0);
5044 }
5045
5046 #endif /* 1 || COMPAT_PRELITE2 */
5047 #endif /* !BURN_BRIDGES */
5048
5049 static void
unmount_or_warn(struct mount * mp)5050 unmount_or_warn(struct mount *mp)
5051 {
5052 int error;
5053
5054 error = dounmount(mp, MNT_FORCE, curthread);
5055 if (error != 0) {
5056 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
5057 if (error == EBUSY)
5058 printf("BUSY)\n");
5059 else
5060 printf("%d)\n", error);
5061 }
5062 }
5063
5064 /*
5065 * Unmount all filesystems. The list is traversed in reverse order
5066 * of mounting to avoid dependencies.
5067 */
5068 void
vfs_unmountall(void)5069 vfs_unmountall(void)
5070 {
5071 struct mount *mp, *tmp;
5072
5073 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
5074
5075 /*
5076 * Since this only runs when rebooting, it is not interlocked.
5077 */
5078 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
5079 vfs_ref(mp);
5080
5081 /*
5082 * Forcibly unmounting "/dev" before "/" would prevent clean
5083 * unmount of the latter.
5084 */
5085 if (mp == rootdevmp)
5086 continue;
5087
5088 unmount_or_warn(mp);
5089 }
5090
5091 if (rootdevmp != NULL)
5092 unmount_or_warn(rootdevmp);
5093 }
5094
5095 static void
vfs_deferred_inactive(struct vnode * vp,int lkflags)5096 vfs_deferred_inactive(struct vnode *vp, int lkflags)
5097 {
5098
5099 ASSERT_VI_LOCKED(vp, __func__);
5100 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
5101 if ((vp->v_iflag & VI_OWEINACT) == 0) {
5102 vdropl(vp);
5103 return;
5104 }
5105 if (vn_lock(vp, lkflags) == 0) {
5106 VI_LOCK(vp);
5107 vinactive(vp);
5108 VOP_UNLOCK(vp);
5109 vdropl(vp);
5110 return;
5111 }
5112 vdefer_inactive_unlocked(vp);
5113 }
5114
5115 static int
vfs_periodic_inactive_filter(struct vnode * vp,void * arg)5116 vfs_periodic_inactive_filter(struct vnode *vp, void *arg)
5117 {
5118
5119 return (vp->v_iflag & VI_DEFINACT);
5120 }
5121
5122 static void __noinline
vfs_periodic_inactive(struct mount * mp,int flags)5123 vfs_periodic_inactive(struct mount *mp, int flags)
5124 {
5125 struct vnode *vp, *mvp;
5126 int lkflags;
5127
5128 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5129 if (flags != MNT_WAIT)
5130 lkflags |= LK_NOWAIT;
5131
5132 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) {
5133 if ((vp->v_iflag & VI_DEFINACT) == 0) {
5134 VI_UNLOCK(vp);
5135 continue;
5136 }
5137 vp->v_iflag &= ~VI_DEFINACT;
5138 vfs_deferred_inactive(vp, lkflags);
5139 }
5140 }
5141
5142 static inline bool
vfs_want_msync(struct vnode * vp)5143 vfs_want_msync(struct vnode *vp)
5144 {
5145 struct vm_object *obj;
5146
5147 /*
5148 * This test may be performed without any locks held.
5149 * We rely on vm_object's type stability.
5150 */
5151 if (vp->v_vflag & VV_NOSYNC)
5152 return (false);
5153 obj = vp->v_object;
5154 return (obj != NULL && vm_object_mightbedirty(obj));
5155 }
5156
5157 static int
vfs_periodic_msync_inactive_filter(struct vnode * vp,void * arg __unused)5158 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused)
5159 {
5160
5161 if (vp->v_vflag & VV_NOSYNC)
5162 return (false);
5163 if (vp->v_iflag & VI_DEFINACT)
5164 return (true);
5165 return (vfs_want_msync(vp));
5166 }
5167
5168 static void __noinline
vfs_periodic_msync_inactive(struct mount * mp,int flags)5169 vfs_periodic_msync_inactive(struct mount *mp, int flags)
5170 {
5171 struct vnode *vp, *mvp;
5172 int lkflags;
5173 bool seen_defer;
5174
5175 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5176 if (flags != MNT_WAIT)
5177 lkflags |= LK_NOWAIT;
5178
5179 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) {
5180 seen_defer = false;
5181 if (vp->v_iflag & VI_DEFINACT) {
5182 vp->v_iflag &= ~VI_DEFINACT;
5183 seen_defer = true;
5184 }
5185 if (!vfs_want_msync(vp)) {
5186 if (seen_defer)
5187 vfs_deferred_inactive(vp, lkflags);
5188 else
5189 VI_UNLOCK(vp);
5190 continue;
5191 }
5192 if (vget(vp, lkflags) == 0) {
5193 if ((vp->v_vflag & VV_NOSYNC) == 0) {
5194 if (flags == MNT_WAIT)
5195 vnode_pager_clean_sync(vp);
5196 else
5197 vnode_pager_clean_async(vp);
5198 }
5199 vput(vp);
5200 if (seen_defer)
5201 vdrop(vp);
5202 } else {
5203 if (seen_defer)
5204 vdefer_inactive_unlocked(vp);
5205 }
5206 }
5207 }
5208
5209 void
vfs_periodic(struct mount * mp,int flags)5210 vfs_periodic(struct mount *mp, int flags)
5211 {
5212
5213 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
5214
5215 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0)
5216 vfs_periodic_inactive(mp, flags);
5217 else
5218 vfs_periodic_msync_inactive(mp, flags);
5219 }
5220
5221 static void
destroy_vpollinfo_free(struct vpollinfo * vi)5222 destroy_vpollinfo_free(struct vpollinfo *vi)
5223 {
5224
5225 knlist_destroy(&vi->vpi_selinfo.si_note);
5226 mtx_destroy(&vi->vpi_lock);
5227 free(vi, M_VNODEPOLL);
5228 }
5229
5230 static void
destroy_vpollinfo(struct vpollinfo * vi)5231 destroy_vpollinfo(struct vpollinfo *vi)
5232 {
5233
5234 knlist_clear(&vi->vpi_selinfo.si_note, 1);
5235 seldrain(&vi->vpi_selinfo);
5236 destroy_vpollinfo_free(vi);
5237 }
5238
5239 /*
5240 * Initialize per-vnode helper structure to hold poll-related state.
5241 */
5242 void
v_addpollinfo(struct vnode * vp)5243 v_addpollinfo(struct vnode *vp)
5244 {
5245 struct vpollinfo *vi;
5246
5247 if (vp->v_pollinfo != NULL)
5248 return;
5249 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO);
5250 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
5251 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
5252 vfs_knlunlock, vfs_knl_assert_lock);
5253 VI_LOCK(vp);
5254 if (vp->v_pollinfo != NULL) {
5255 VI_UNLOCK(vp);
5256 destroy_vpollinfo_free(vi);
5257 return;
5258 }
5259 vp->v_pollinfo = vi;
5260 VI_UNLOCK(vp);
5261 }
5262
5263 /*
5264 * Record a process's interest in events which might happen to
5265 * a vnode. Because poll uses the historic select-style interface
5266 * internally, this routine serves as both the ``check for any
5267 * pending events'' and the ``record my interest in future events''
5268 * functions. (These are done together, while the lock is held,
5269 * to avoid race conditions.)
5270 */
5271 int
vn_pollrecord(struct vnode * vp,struct thread * td,int events)5272 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
5273 {
5274
5275 v_addpollinfo(vp);
5276 mtx_lock(&vp->v_pollinfo->vpi_lock);
5277 if (vp->v_pollinfo->vpi_revents & events) {
5278 /*
5279 * This leaves events we are not interested
5280 * in available for the other process which
5281 * which presumably had requested them
5282 * (otherwise they would never have been
5283 * recorded).
5284 */
5285 events &= vp->v_pollinfo->vpi_revents;
5286 vp->v_pollinfo->vpi_revents &= ~events;
5287
5288 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5289 return (events);
5290 }
5291 vp->v_pollinfo->vpi_events |= events;
5292 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
5293 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5294 return (0);
5295 }
5296
5297 /*
5298 * Routine to create and manage a filesystem syncer vnode.
5299 */
5300 #define sync_close ((int (*)(struct vop_close_args *))nullop)
5301 static int sync_fsync(struct vop_fsync_args *);
5302 static int sync_inactive(struct vop_inactive_args *);
5303 static int sync_reclaim(struct vop_reclaim_args *);
5304
5305 static struct vop_vector sync_vnodeops = {
5306 .vop_bypass = VOP_EOPNOTSUPP,
5307 .vop_close = sync_close,
5308 .vop_fsync = sync_fsync,
5309 .vop_getwritemount = vop_stdgetwritemount,
5310 .vop_inactive = sync_inactive,
5311 .vop_need_inactive = vop_stdneed_inactive,
5312 .vop_reclaim = sync_reclaim,
5313 .vop_lock1 = vop_stdlock,
5314 .vop_unlock = vop_stdunlock,
5315 .vop_islocked = vop_stdislocked,
5316 .vop_fplookup_vexec = VOP_EAGAIN,
5317 .vop_fplookup_symlink = VOP_EAGAIN,
5318 };
5319 VFS_VOP_VECTOR_REGISTER(sync_vnodeops);
5320
5321 /*
5322 * Create a new filesystem syncer vnode for the specified mount point.
5323 */
5324 void
vfs_allocate_syncvnode(struct mount * mp)5325 vfs_allocate_syncvnode(struct mount *mp)
5326 {
5327 struct vnode *vp;
5328 struct bufobj *bo;
5329 static long start, incr, next;
5330 int error;
5331
5332 /* Allocate a new vnode */
5333 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
5334 if (error != 0)
5335 panic("vfs_allocate_syncvnode: getnewvnode() failed");
5336 vp->v_type = VNON;
5337 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5338 vp->v_vflag |= VV_FORCEINSMQ;
5339 error = insmntque1(vp, mp);
5340 if (error != 0)
5341 panic("vfs_allocate_syncvnode: insmntque() failed");
5342 vp->v_vflag &= ~VV_FORCEINSMQ;
5343 vn_set_state(vp, VSTATE_CONSTRUCTED);
5344 VOP_UNLOCK(vp);
5345 /*
5346 * Place the vnode onto the syncer worklist. We attempt to
5347 * scatter them about on the list so that they will go off
5348 * at evenly distributed times even if all the filesystems
5349 * are mounted at once.
5350 */
5351 next += incr;
5352 if (next == 0 || next > syncer_maxdelay) {
5353 start /= 2;
5354 incr /= 2;
5355 if (start == 0) {
5356 start = syncer_maxdelay / 2;
5357 incr = syncer_maxdelay;
5358 }
5359 next = start;
5360 }
5361 bo = &vp->v_bufobj;
5362 BO_LOCK(bo);
5363 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
5364 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
5365 mtx_lock(&sync_mtx);
5366 sync_vnode_count++;
5367 if (mp->mnt_syncer == NULL) {
5368 mp->mnt_syncer = vp;
5369 vp = NULL;
5370 }
5371 mtx_unlock(&sync_mtx);
5372 BO_UNLOCK(bo);
5373 if (vp != NULL) {
5374 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5375 vgone(vp);
5376 vput(vp);
5377 }
5378 }
5379
5380 void
vfs_deallocate_syncvnode(struct mount * mp)5381 vfs_deallocate_syncvnode(struct mount *mp)
5382 {
5383 struct vnode *vp;
5384
5385 mtx_lock(&sync_mtx);
5386 vp = mp->mnt_syncer;
5387 if (vp != NULL)
5388 mp->mnt_syncer = NULL;
5389 mtx_unlock(&sync_mtx);
5390 if (vp != NULL)
5391 vrele(vp);
5392 }
5393
5394 /*
5395 * Do a lazy sync of the filesystem.
5396 */
5397 static int
sync_fsync(struct vop_fsync_args * ap)5398 sync_fsync(struct vop_fsync_args *ap)
5399 {
5400 struct vnode *syncvp = ap->a_vp;
5401 struct mount *mp = syncvp->v_mount;
5402 int error, save;
5403 struct bufobj *bo;
5404
5405 /*
5406 * We only need to do something if this is a lazy evaluation.
5407 */
5408 if (ap->a_waitfor != MNT_LAZY)
5409 return (0);
5410
5411 /*
5412 * Move ourselves to the back of the sync list.
5413 */
5414 bo = &syncvp->v_bufobj;
5415 BO_LOCK(bo);
5416 vn_syncer_add_to_worklist(bo, syncdelay);
5417 BO_UNLOCK(bo);
5418
5419 /*
5420 * Walk the list of vnodes pushing all that are dirty and
5421 * not already on the sync list.
5422 */
5423 if (vfs_busy(mp, MBF_NOWAIT) != 0)
5424 return (0);
5425 VOP_UNLOCK(syncvp);
5426 save = curthread_pflags_set(TDP_SYNCIO);
5427 /*
5428 * The filesystem at hand may be idle with free vnodes stored in the
5429 * batch. Return them instead of letting them stay there indefinitely.
5430 */
5431 vfs_periodic(mp, MNT_NOWAIT);
5432 error = VFS_SYNC(mp, MNT_LAZY);
5433 curthread_pflags_restore(save);
5434 vn_lock(syncvp, LK_EXCLUSIVE | LK_RETRY);
5435 vfs_unbusy(mp);
5436 return (error);
5437 }
5438
5439 /*
5440 * The syncer vnode is no referenced.
5441 */
5442 static int
sync_inactive(struct vop_inactive_args * ap)5443 sync_inactive(struct vop_inactive_args *ap)
5444 {
5445
5446 vgone(ap->a_vp);
5447 return (0);
5448 }
5449
5450 /*
5451 * The syncer vnode is no longer needed and is being decommissioned.
5452 *
5453 * Modifications to the worklist must be protected by sync_mtx.
5454 */
5455 static int
sync_reclaim(struct vop_reclaim_args * ap)5456 sync_reclaim(struct vop_reclaim_args *ap)
5457 {
5458 struct vnode *vp = ap->a_vp;
5459 struct bufobj *bo;
5460
5461 bo = &vp->v_bufobj;
5462 BO_LOCK(bo);
5463 mtx_lock(&sync_mtx);
5464 if (vp->v_mount->mnt_syncer == vp)
5465 vp->v_mount->mnt_syncer = NULL;
5466 if (bo->bo_flag & BO_ONWORKLST) {
5467 LIST_REMOVE(bo, bo_synclist);
5468 syncer_worklist_len--;
5469 sync_vnode_count--;
5470 bo->bo_flag &= ~BO_ONWORKLST;
5471 }
5472 mtx_unlock(&sync_mtx);
5473 BO_UNLOCK(bo);
5474
5475 return (0);
5476 }
5477
5478 int
vn_need_pageq_flush(struct vnode * vp)5479 vn_need_pageq_flush(struct vnode *vp)
5480 {
5481 struct vm_object *obj;
5482
5483 obj = vp->v_object;
5484 return (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
5485 vm_object_mightbedirty(obj));
5486 }
5487
5488 /*
5489 * Check if vnode represents a disk device
5490 */
5491 bool
vn_isdisk_error(struct vnode * vp,int * errp)5492 vn_isdisk_error(struct vnode *vp, int *errp)
5493 {
5494 int error;
5495
5496 if (vp->v_type != VCHR) {
5497 error = ENOTBLK;
5498 goto out;
5499 }
5500 error = 0;
5501 dev_lock();
5502 if (vp->v_rdev == NULL)
5503 error = ENXIO;
5504 else if (vp->v_rdev->si_devsw == NULL)
5505 error = ENXIO;
5506 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
5507 error = ENOTBLK;
5508 dev_unlock();
5509 out:
5510 *errp = error;
5511 return (error == 0);
5512 }
5513
5514 bool
vn_isdisk(struct vnode * vp)5515 vn_isdisk(struct vnode *vp)
5516 {
5517 int error;
5518
5519 return (vn_isdisk_error(vp, &error));
5520 }
5521
5522 /*
5523 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see
5524 * the comment above cache_fplookup for details.
5525 */
5526 int
vaccess_vexec_smr(mode_t file_mode,uid_t file_uid,gid_t file_gid,struct ucred * cred)5527 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred)
5528 {
5529 int error;
5530
5531 VFS_SMR_ASSERT_ENTERED();
5532
5533 /* Check the owner. */
5534 if (cred->cr_uid == file_uid) {
5535 if (file_mode & S_IXUSR)
5536 return (0);
5537 goto out_error;
5538 }
5539
5540 /* Otherwise, check the groups (first match) */
5541 if (groupmember(file_gid, cred)) {
5542 if (file_mode & S_IXGRP)
5543 return (0);
5544 goto out_error;
5545 }
5546
5547 /* Otherwise, check everyone else. */
5548 if (file_mode & S_IXOTH)
5549 return (0);
5550 out_error:
5551 /*
5552 * Permission check failed, but it is possible denial will get overwritten
5553 * (e.g., when root is traversing through a 700 directory owned by someone
5554 * else).
5555 *
5556 * vaccess() calls priv_check_cred which in turn can descent into MAC
5557 * modules overriding this result. It's quite unclear what semantics
5558 * are allowed for them to operate, thus for safety we don't call them
5559 * from within the SMR section. This also means if any such modules
5560 * are present, we have to let the regular lookup decide.
5561 */
5562 error = priv_check_cred_vfs_lookup_nomac(cred);
5563 switch (error) {
5564 case 0:
5565 return (0);
5566 case EAGAIN:
5567 /*
5568 * MAC modules present.
5569 */
5570 return (EAGAIN);
5571 case EPERM:
5572 return (EACCES);
5573 default:
5574 return (error);
5575 }
5576 }
5577
5578 /*
5579 * Common filesystem object access control check routine. Accepts a
5580 * vnode's type, "mode", uid and gid, requested access mode, and credentials.
5581 * Returns 0 on success, or an errno on failure.
5582 */
5583 int
vaccess(__enum_uint8 (vtype)type,mode_t file_mode,uid_t file_uid,gid_t file_gid,accmode_t accmode,struct ucred * cred)5584 vaccess(__enum_uint8(vtype) type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
5585 accmode_t accmode, struct ucred *cred)
5586 {
5587 accmode_t dac_granted;
5588 accmode_t priv_granted;
5589
5590 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
5591 ("invalid bit in accmode"));
5592 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
5593 ("VAPPEND without VWRITE"));
5594
5595 /*
5596 * Look for a normal, non-privileged way to access the file/directory
5597 * as requested. If it exists, go with that.
5598 */
5599
5600 dac_granted = 0;
5601
5602 /* Check the owner. */
5603 if (cred->cr_uid == file_uid) {
5604 dac_granted |= VADMIN;
5605 if (file_mode & S_IXUSR)
5606 dac_granted |= VEXEC;
5607 if (file_mode & S_IRUSR)
5608 dac_granted |= VREAD;
5609 if (file_mode & S_IWUSR)
5610 dac_granted |= (VWRITE | VAPPEND);
5611
5612 if ((accmode & dac_granted) == accmode)
5613 return (0);
5614
5615 goto privcheck;
5616 }
5617
5618 /* Otherwise, check the groups (first match) */
5619 if (groupmember(file_gid, cred)) {
5620 if (file_mode & S_IXGRP)
5621 dac_granted |= VEXEC;
5622 if (file_mode & S_IRGRP)
5623 dac_granted |= VREAD;
5624 if (file_mode & S_IWGRP)
5625 dac_granted |= (VWRITE | VAPPEND);
5626
5627 if ((accmode & dac_granted) == accmode)
5628 return (0);
5629
5630 goto privcheck;
5631 }
5632
5633 /* Otherwise, check everyone else. */
5634 if (file_mode & S_IXOTH)
5635 dac_granted |= VEXEC;
5636 if (file_mode & S_IROTH)
5637 dac_granted |= VREAD;
5638 if (file_mode & S_IWOTH)
5639 dac_granted |= (VWRITE | VAPPEND);
5640 if ((accmode & dac_granted) == accmode)
5641 return (0);
5642
5643 privcheck:
5644 /*
5645 * Build a privilege mask to determine if the set of privileges
5646 * satisfies the requirements when combined with the granted mask
5647 * from above. For each privilege, if the privilege is required,
5648 * bitwise or the request type onto the priv_granted mask.
5649 */
5650 priv_granted = 0;
5651
5652 if (type == VDIR) {
5653 /*
5654 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
5655 * requests, instead of PRIV_VFS_EXEC.
5656 */
5657 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5658 !priv_check_cred(cred, PRIV_VFS_LOOKUP))
5659 priv_granted |= VEXEC;
5660 } else {
5661 /*
5662 * Ensure that at least one execute bit is on. Otherwise,
5663 * a privileged user will always succeed, and we don't want
5664 * this to happen unless the file really is executable.
5665 */
5666 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5667 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
5668 !priv_check_cred(cred, PRIV_VFS_EXEC))
5669 priv_granted |= VEXEC;
5670 }
5671
5672 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
5673 !priv_check_cred(cred, PRIV_VFS_READ))
5674 priv_granted |= VREAD;
5675
5676 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
5677 !priv_check_cred(cred, PRIV_VFS_WRITE))
5678 priv_granted |= (VWRITE | VAPPEND);
5679
5680 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
5681 !priv_check_cred(cred, PRIV_VFS_ADMIN))
5682 priv_granted |= VADMIN;
5683
5684 if ((accmode & (priv_granted | dac_granted)) == accmode) {
5685 return (0);
5686 }
5687
5688 return ((accmode & VADMIN) ? EPERM : EACCES);
5689 }
5690
5691 /*
5692 * Credential check based on process requesting service, and per-attribute
5693 * permissions.
5694 */
5695 int
extattr_check_cred(struct vnode * vp,int attrnamespace,struct ucred * cred,struct thread * td,accmode_t accmode)5696 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
5697 struct thread *td, accmode_t accmode)
5698 {
5699
5700 /*
5701 * Kernel-invoked always succeeds.
5702 */
5703 if (cred == NOCRED)
5704 return (0);
5705
5706 /*
5707 * Do not allow privileged processes in jail to directly manipulate
5708 * system attributes.
5709 */
5710 switch (attrnamespace) {
5711 case EXTATTR_NAMESPACE_SYSTEM:
5712 /* Potentially should be: return (EPERM); */
5713 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM));
5714 case EXTATTR_NAMESPACE_USER:
5715 return (VOP_ACCESS(vp, accmode, cred, td));
5716 default:
5717 return (EPERM);
5718 }
5719 }
5720
5721 #ifdef DEBUG_VFS_LOCKS
5722 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
5723 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
5724 "Drop into debugger on lock violation");
5725
5726 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
5727 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
5728 0, "Check for interlock across VOPs");
5729
5730 int vfs_badlock_print = 1; /* Print lock violations. */
5731 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
5732 0, "Print lock violations");
5733
5734 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
5735 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
5736 0, "Print vnode details on lock violations");
5737
5738 #ifdef KDB
5739 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
5740 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
5741 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
5742 #endif
5743
5744 static void
vfs_badlock(const char * msg,const char * str,struct vnode * vp)5745 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
5746 {
5747
5748 #ifdef KDB
5749 if (vfs_badlock_backtrace)
5750 kdb_backtrace();
5751 #endif
5752 if (vfs_badlock_vnode)
5753 vn_printf(vp, "vnode ");
5754 if (vfs_badlock_print)
5755 printf("%s: %p %s\n", str, (void *)vp, msg);
5756 if (vfs_badlock_ddb)
5757 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5758 }
5759
5760 void
assert_vi_locked(struct vnode * vp,const char * str)5761 assert_vi_locked(struct vnode *vp, const char *str)
5762 {
5763
5764 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
5765 vfs_badlock("interlock is not locked but should be", str, vp);
5766 }
5767
5768 void
assert_vi_unlocked(struct vnode * vp,const char * str)5769 assert_vi_unlocked(struct vnode *vp, const char *str)
5770 {
5771
5772 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
5773 vfs_badlock("interlock is locked but should not be", str, vp);
5774 }
5775
5776 void
assert_vop_locked(struct vnode * vp,const char * str)5777 assert_vop_locked(struct vnode *vp, const char *str)
5778 {
5779 if (KERNEL_PANICKED() || vp == NULL)
5780 return;
5781
5782 #ifdef WITNESS
5783 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5784 witness_is_owned(&vp->v_vnlock->lock_object) == -1)
5785 #else
5786 int locked = VOP_ISLOCKED(vp);
5787 if (locked == 0 || locked == LK_EXCLOTHER)
5788 #endif
5789 vfs_badlock("is not locked but should be", str, vp);
5790 }
5791
5792 void
assert_vop_unlocked(struct vnode * vp,const char * str)5793 assert_vop_unlocked(struct vnode *vp, const char *str)
5794 {
5795 if (KERNEL_PANICKED() || vp == NULL)
5796 return;
5797
5798 #ifdef WITNESS
5799 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5800 witness_is_owned(&vp->v_vnlock->lock_object) == 1)
5801 #else
5802 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
5803 #endif
5804 vfs_badlock("is locked but should not be", str, vp);
5805 }
5806
5807 void
assert_vop_elocked(struct vnode * vp,const char * str)5808 assert_vop_elocked(struct vnode *vp, const char *str)
5809 {
5810 if (KERNEL_PANICKED() || vp == NULL)
5811 return;
5812
5813 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
5814 vfs_badlock("is not exclusive locked but should be", str, vp);
5815 }
5816 #endif /* DEBUG_VFS_LOCKS */
5817
5818 void
vop_rename_fail(struct vop_rename_args * ap)5819 vop_rename_fail(struct vop_rename_args *ap)
5820 {
5821
5822 if (ap->a_tvp != NULL)
5823 vput(ap->a_tvp);
5824 if (ap->a_tdvp == ap->a_tvp)
5825 vrele(ap->a_tdvp);
5826 else
5827 vput(ap->a_tdvp);
5828 vrele(ap->a_fdvp);
5829 vrele(ap->a_fvp);
5830 }
5831
5832 void
vop_rename_pre(void * ap)5833 vop_rename_pre(void *ap)
5834 {
5835 struct vop_rename_args *a = ap;
5836
5837 #ifdef DEBUG_VFS_LOCKS
5838 if (a->a_tvp)
5839 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
5840 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
5841 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
5842 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
5843
5844 /* Check the source (from). */
5845 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
5846 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
5847 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
5848 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
5849 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
5850
5851 /* Check the target. */
5852 if (a->a_tvp)
5853 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
5854 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
5855 #endif
5856 /*
5857 * It may be tempting to add vn_seqc_write_begin/end calls here and
5858 * in vop_rename_post but that's not going to work out since some
5859 * filesystems relookup vnodes mid-rename. This is probably a bug.
5860 *
5861 * For now filesystems are expected to do the relevant calls after they
5862 * decide what vnodes to operate on.
5863 */
5864 if (a->a_tdvp != a->a_fdvp)
5865 vhold(a->a_fdvp);
5866 if (a->a_tvp != a->a_fvp)
5867 vhold(a->a_fvp);
5868 vhold(a->a_tdvp);
5869 if (a->a_tvp)
5870 vhold(a->a_tvp);
5871 }
5872
5873 #ifdef DEBUG_VFS_LOCKS
5874 void
vop_fplookup_vexec_debugpre(void * ap __unused)5875 vop_fplookup_vexec_debugpre(void *ap __unused)
5876 {
5877
5878 VFS_SMR_ASSERT_ENTERED();
5879 }
5880
5881 void
vop_fplookup_vexec_debugpost(void * ap,int rc)5882 vop_fplookup_vexec_debugpost(void *ap, int rc)
5883 {
5884 struct vop_fplookup_vexec_args *a;
5885 struct vnode *vp;
5886
5887 a = ap;
5888 vp = a->a_vp;
5889
5890 VFS_SMR_ASSERT_ENTERED();
5891 if (rc == EOPNOTSUPP)
5892 VNPASS(VN_IS_DOOMED(vp), vp);
5893 }
5894
5895 void
vop_fplookup_symlink_debugpre(void * ap __unused)5896 vop_fplookup_symlink_debugpre(void *ap __unused)
5897 {
5898
5899 VFS_SMR_ASSERT_ENTERED();
5900 }
5901
5902 void
vop_fplookup_symlink_debugpost(void * ap __unused,int rc __unused)5903 vop_fplookup_symlink_debugpost(void *ap __unused, int rc __unused)
5904 {
5905
5906 VFS_SMR_ASSERT_ENTERED();
5907 }
5908
5909 static void
vop_fsync_debugprepost(struct vnode * vp,const char * name)5910 vop_fsync_debugprepost(struct vnode *vp, const char *name)
5911 {
5912 if (vp->v_type == VCHR)
5913 ;
5914 /*
5915 * The shared vs. exclusive locking policy for fsync()
5916 * is actually determined by vp's write mount as indicated
5917 * by VOP_GETWRITEMOUNT(), which for stacked filesystems
5918 * may not be the same as vp->v_mount. However, if the
5919 * underlying filesystem which really handles the fsync()
5920 * supports shared locking, the stacked filesystem must also
5921 * be prepared for its VOP_FSYNC() operation to be called
5922 * with only a shared lock. On the other hand, if the
5923 * stacked filesystem claims support for shared write
5924 * locking but the underlying filesystem does not, and the
5925 * caller incorrectly uses a shared lock, this condition
5926 * should still be caught when the stacked filesystem
5927 * invokes VOP_FSYNC() on the underlying filesystem.
5928 */
5929 else if (MNT_SHARED_WRITES(vp->v_mount))
5930 ASSERT_VOP_LOCKED(vp, name);
5931 else
5932 ASSERT_VOP_ELOCKED(vp, name);
5933 }
5934
5935 void
vop_fsync_debugpre(void * a)5936 vop_fsync_debugpre(void *a)
5937 {
5938 struct vop_fsync_args *ap;
5939
5940 ap = a;
5941 vop_fsync_debugprepost(ap->a_vp, "fsync");
5942 }
5943
5944 void
vop_fsync_debugpost(void * a,int rc __unused)5945 vop_fsync_debugpost(void *a, int rc __unused)
5946 {
5947 struct vop_fsync_args *ap;
5948
5949 ap = a;
5950 vop_fsync_debugprepost(ap->a_vp, "fsync");
5951 }
5952
5953 void
vop_fdatasync_debugpre(void * a)5954 vop_fdatasync_debugpre(void *a)
5955 {
5956 struct vop_fdatasync_args *ap;
5957
5958 ap = a;
5959 vop_fsync_debugprepost(ap->a_vp, "fsync");
5960 }
5961
5962 void
vop_fdatasync_debugpost(void * a,int rc __unused)5963 vop_fdatasync_debugpost(void *a, int rc __unused)
5964 {
5965 struct vop_fdatasync_args *ap;
5966
5967 ap = a;
5968 vop_fsync_debugprepost(ap->a_vp, "fsync");
5969 }
5970
5971 void
vop_strategy_debugpre(void * ap)5972 vop_strategy_debugpre(void *ap)
5973 {
5974 struct vop_strategy_args *a;
5975 struct buf *bp;
5976
5977 a = ap;
5978 bp = a->a_bp;
5979
5980 /*
5981 * Cluster ops lock their component buffers but not the IO container.
5982 */
5983 if ((bp->b_flags & B_CLUSTER) != 0)
5984 return;
5985
5986 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) {
5987 if (vfs_badlock_print)
5988 printf(
5989 "VOP_STRATEGY: bp is not locked but should be\n");
5990 if (vfs_badlock_ddb)
5991 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5992 }
5993 }
5994
5995 void
vop_lock_debugpre(void * ap)5996 vop_lock_debugpre(void *ap)
5997 {
5998 struct vop_lock1_args *a = ap;
5999
6000 if ((a->a_flags & LK_INTERLOCK) == 0)
6001 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
6002 else
6003 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
6004 }
6005
6006 void
vop_lock_debugpost(void * ap,int rc)6007 vop_lock_debugpost(void *ap, int rc)
6008 {
6009 struct vop_lock1_args *a = ap;
6010
6011 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
6012 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
6013 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
6014 }
6015
6016 void
vop_unlock_debugpre(void * ap)6017 vop_unlock_debugpre(void *ap)
6018 {
6019 struct vop_unlock_args *a = ap;
6020 struct vnode *vp = a->a_vp;
6021
6022 VNPASS(vn_get_state(vp) != VSTATE_UNINITIALIZED, vp);
6023 ASSERT_VOP_LOCKED(vp, "VOP_UNLOCK");
6024 }
6025
6026 void
vop_need_inactive_debugpre(void * ap)6027 vop_need_inactive_debugpre(void *ap)
6028 {
6029 struct vop_need_inactive_args *a = ap;
6030
6031 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
6032 }
6033
6034 void
vop_need_inactive_debugpost(void * ap,int rc)6035 vop_need_inactive_debugpost(void *ap, int rc)
6036 {
6037 struct vop_need_inactive_args *a = ap;
6038
6039 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
6040 }
6041 #endif
6042
6043 void
vop_create_pre(void * ap)6044 vop_create_pre(void *ap)
6045 {
6046 struct vop_create_args *a;
6047 struct vnode *dvp;
6048
6049 a = ap;
6050 dvp = a->a_dvp;
6051 vn_seqc_write_begin(dvp);
6052 }
6053
6054 void
vop_create_post(void * ap,int rc)6055 vop_create_post(void *ap, int rc)
6056 {
6057 struct vop_create_args *a;
6058 struct vnode *dvp;
6059
6060 a = ap;
6061 dvp = a->a_dvp;
6062 vn_seqc_write_end(dvp);
6063 if (!rc)
6064 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6065 }
6066
6067 void
vop_whiteout_pre(void * ap)6068 vop_whiteout_pre(void *ap)
6069 {
6070 struct vop_whiteout_args *a;
6071 struct vnode *dvp;
6072
6073 a = ap;
6074 dvp = a->a_dvp;
6075 vn_seqc_write_begin(dvp);
6076 }
6077
6078 void
vop_whiteout_post(void * ap,int rc)6079 vop_whiteout_post(void *ap, int rc)
6080 {
6081 struct vop_whiteout_args *a;
6082 struct vnode *dvp;
6083
6084 a = ap;
6085 dvp = a->a_dvp;
6086 vn_seqc_write_end(dvp);
6087 }
6088
6089 void
vop_deleteextattr_pre(void * ap)6090 vop_deleteextattr_pre(void *ap)
6091 {
6092 struct vop_deleteextattr_args *a;
6093 struct vnode *vp;
6094
6095 a = ap;
6096 vp = a->a_vp;
6097 vn_seqc_write_begin(vp);
6098 }
6099
6100 void
vop_deleteextattr_post(void * ap,int rc)6101 vop_deleteextattr_post(void *ap, int rc)
6102 {
6103 struct vop_deleteextattr_args *a;
6104 struct vnode *vp;
6105
6106 a = ap;
6107 vp = a->a_vp;
6108 vn_seqc_write_end(vp);
6109 if (!rc)
6110 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
6111 }
6112
6113 void
vop_link_pre(void * ap)6114 vop_link_pre(void *ap)
6115 {
6116 struct vop_link_args *a;
6117 struct vnode *vp, *tdvp;
6118
6119 a = ap;
6120 vp = a->a_vp;
6121 tdvp = a->a_tdvp;
6122 vn_seqc_write_begin(vp);
6123 vn_seqc_write_begin(tdvp);
6124 }
6125
6126 void
vop_link_post(void * ap,int rc)6127 vop_link_post(void *ap, int rc)
6128 {
6129 struct vop_link_args *a;
6130 struct vnode *vp, *tdvp;
6131
6132 a = ap;
6133 vp = a->a_vp;
6134 tdvp = a->a_tdvp;
6135 vn_seqc_write_end(vp);
6136 vn_seqc_write_end(tdvp);
6137 if (!rc) {
6138 VFS_KNOTE_LOCKED(vp, NOTE_LINK);
6139 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE);
6140 }
6141 }
6142
6143 void
vop_mkdir_pre(void * ap)6144 vop_mkdir_pre(void *ap)
6145 {
6146 struct vop_mkdir_args *a;
6147 struct vnode *dvp;
6148
6149 a = ap;
6150 dvp = a->a_dvp;
6151 vn_seqc_write_begin(dvp);
6152 }
6153
6154 void
vop_mkdir_post(void * ap,int rc)6155 vop_mkdir_post(void *ap, int rc)
6156 {
6157 struct vop_mkdir_args *a;
6158 struct vnode *dvp;
6159
6160 a = ap;
6161 dvp = a->a_dvp;
6162 vn_seqc_write_end(dvp);
6163 if (!rc)
6164 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6165 }
6166
6167 #ifdef DEBUG_VFS_LOCKS
6168 void
vop_mkdir_debugpost(void * ap,int rc)6169 vop_mkdir_debugpost(void *ap, int rc)
6170 {
6171 struct vop_mkdir_args *a;
6172
6173 a = ap;
6174 if (!rc)
6175 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp);
6176 }
6177 #endif
6178
6179 void
vop_mknod_pre(void * ap)6180 vop_mknod_pre(void *ap)
6181 {
6182 struct vop_mknod_args *a;
6183 struct vnode *dvp;
6184
6185 a = ap;
6186 dvp = a->a_dvp;
6187 vn_seqc_write_begin(dvp);
6188 }
6189
6190 void
vop_mknod_post(void * ap,int rc)6191 vop_mknod_post(void *ap, int rc)
6192 {
6193 struct vop_mknod_args *a;
6194 struct vnode *dvp;
6195
6196 a = ap;
6197 dvp = a->a_dvp;
6198 vn_seqc_write_end(dvp);
6199 if (!rc)
6200 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6201 }
6202
6203 void
vop_reclaim_post(void * ap,int rc)6204 vop_reclaim_post(void *ap, int rc)
6205 {
6206 struct vop_reclaim_args *a;
6207 struct vnode *vp;
6208
6209 a = ap;
6210 vp = a->a_vp;
6211 ASSERT_VOP_IN_SEQC(vp);
6212 if (!rc)
6213 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE);
6214 }
6215
6216 void
vop_remove_pre(void * ap)6217 vop_remove_pre(void *ap)
6218 {
6219 struct vop_remove_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_begin(dvp);
6226 vn_seqc_write_begin(vp);
6227 }
6228
6229 void
vop_remove_post(void * ap,int rc)6230 vop_remove_post(void *ap, int rc)
6231 {
6232 struct vop_remove_args *a;
6233 struct vnode *dvp, *vp;
6234
6235 a = ap;
6236 dvp = a->a_dvp;
6237 vp = a->a_vp;
6238 vn_seqc_write_end(dvp);
6239 vn_seqc_write_end(vp);
6240 if (!rc) {
6241 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6242 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6243 }
6244 }
6245
6246 void
vop_rename_post(void * ap,int rc)6247 vop_rename_post(void *ap, int rc)
6248 {
6249 struct vop_rename_args *a = ap;
6250 long hint;
6251
6252 if (!rc) {
6253 hint = NOTE_WRITE;
6254 if (a->a_fdvp == a->a_tdvp) {
6255 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
6256 hint |= NOTE_LINK;
6257 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6258 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6259 } else {
6260 hint |= NOTE_EXTEND;
6261 if (a->a_fvp->v_type == VDIR)
6262 hint |= NOTE_LINK;
6263 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6264
6265 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
6266 a->a_tvp->v_type == VDIR)
6267 hint &= ~NOTE_LINK;
6268 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6269 }
6270
6271 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
6272 if (a->a_tvp)
6273 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
6274 }
6275 if (a->a_tdvp != a->a_fdvp)
6276 vdrop(a->a_fdvp);
6277 if (a->a_tvp != a->a_fvp)
6278 vdrop(a->a_fvp);
6279 vdrop(a->a_tdvp);
6280 if (a->a_tvp)
6281 vdrop(a->a_tvp);
6282 }
6283
6284 void
vop_rmdir_pre(void * ap)6285 vop_rmdir_pre(void *ap)
6286 {
6287 struct vop_rmdir_args *a;
6288 struct vnode *dvp, *vp;
6289
6290 a = ap;
6291 dvp = a->a_dvp;
6292 vp = a->a_vp;
6293 vn_seqc_write_begin(dvp);
6294 vn_seqc_write_begin(vp);
6295 }
6296
6297 void
vop_rmdir_post(void * ap,int rc)6298 vop_rmdir_post(void *ap, int rc)
6299 {
6300 struct vop_rmdir_args *a;
6301 struct vnode *dvp, *vp;
6302
6303 a = ap;
6304 dvp = a->a_dvp;
6305 vp = a->a_vp;
6306 vn_seqc_write_end(dvp);
6307 vn_seqc_write_end(vp);
6308 if (!rc) {
6309 vp->v_vflag |= VV_UNLINKED;
6310 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6311 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6312 }
6313 }
6314
6315 void
vop_setattr_pre(void * ap)6316 vop_setattr_pre(void *ap)
6317 {
6318 struct vop_setattr_args *a;
6319 struct vnode *vp;
6320
6321 a = ap;
6322 vp = a->a_vp;
6323 vn_seqc_write_begin(vp);
6324 }
6325
6326 void
vop_setattr_post(void * ap,int rc)6327 vop_setattr_post(void *ap, int rc)
6328 {
6329 struct vop_setattr_args *a;
6330 struct vnode *vp;
6331
6332 a = ap;
6333 vp = a->a_vp;
6334 vn_seqc_write_end(vp);
6335 if (!rc)
6336 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6337 }
6338
6339 void
vop_setacl_pre(void * ap)6340 vop_setacl_pre(void *ap)
6341 {
6342 struct vop_setacl_args *a;
6343 struct vnode *vp;
6344
6345 a = ap;
6346 vp = a->a_vp;
6347 vn_seqc_write_begin(vp);
6348 }
6349
6350 void
vop_setacl_post(void * ap,int rc __unused)6351 vop_setacl_post(void *ap, int rc __unused)
6352 {
6353 struct vop_setacl_args *a;
6354 struct vnode *vp;
6355
6356 a = ap;
6357 vp = a->a_vp;
6358 vn_seqc_write_end(vp);
6359 }
6360
6361 void
vop_setextattr_pre(void * ap)6362 vop_setextattr_pre(void *ap)
6363 {
6364 struct vop_setextattr_args *a;
6365 struct vnode *vp;
6366
6367 a = ap;
6368 vp = a->a_vp;
6369 vn_seqc_write_begin(vp);
6370 }
6371
6372 void
vop_setextattr_post(void * ap,int rc)6373 vop_setextattr_post(void *ap, int rc)
6374 {
6375 struct vop_setextattr_args *a;
6376 struct vnode *vp;
6377
6378 a = ap;
6379 vp = a->a_vp;
6380 vn_seqc_write_end(vp);
6381 if (!rc)
6382 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6383 }
6384
6385 void
vop_symlink_pre(void * ap)6386 vop_symlink_pre(void *ap)
6387 {
6388 struct vop_symlink_args *a;
6389 struct vnode *dvp;
6390
6391 a = ap;
6392 dvp = a->a_dvp;
6393 vn_seqc_write_begin(dvp);
6394 }
6395
6396 void
vop_symlink_post(void * ap,int rc)6397 vop_symlink_post(void *ap, int rc)
6398 {
6399 struct vop_symlink_args *a;
6400 struct vnode *dvp;
6401
6402 a = ap;
6403 dvp = a->a_dvp;
6404 vn_seqc_write_end(dvp);
6405 if (!rc)
6406 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6407 }
6408
6409 void
vop_open_post(void * ap,int rc)6410 vop_open_post(void *ap, int rc)
6411 {
6412 struct vop_open_args *a = ap;
6413
6414 if (!rc)
6415 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
6416 }
6417
6418 void
vop_close_post(void * ap,int rc)6419 vop_close_post(void *ap, int rc)
6420 {
6421 struct vop_close_args *a = ap;
6422
6423 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
6424 !VN_IS_DOOMED(a->a_vp))) {
6425 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
6426 NOTE_CLOSE_WRITE : NOTE_CLOSE);
6427 }
6428 }
6429
6430 void
vop_read_post(void * ap,int rc)6431 vop_read_post(void *ap, int rc)
6432 {
6433 struct vop_read_args *a = ap;
6434
6435 if (!rc)
6436 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6437 }
6438
6439 void
vop_read_pgcache_post(void * ap,int rc)6440 vop_read_pgcache_post(void *ap, int rc)
6441 {
6442 struct vop_read_pgcache_args *a = ap;
6443
6444 if (!rc)
6445 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ);
6446 }
6447
6448 void
vop_readdir_post(void * ap,int rc)6449 vop_readdir_post(void *ap, int rc)
6450 {
6451 struct vop_readdir_args *a = ap;
6452
6453 if (!rc)
6454 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6455 }
6456
6457 static struct knlist fs_knlist;
6458
6459 static void
vfs_event_init(void * arg)6460 vfs_event_init(void *arg)
6461 {
6462 knlist_init_mtx(&fs_knlist, NULL);
6463 }
6464 /* XXX - correct order? */
6465 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
6466
6467 void
vfs_event_signal(fsid_t * fsid,uint32_t event,intptr_t data __unused)6468 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
6469 {
6470
6471 KNOTE_UNLOCKED(&fs_knlist, event);
6472 }
6473
6474 static int filt_fsattach(struct knote *kn);
6475 static void filt_fsdetach(struct knote *kn);
6476 static int filt_fsevent(struct knote *kn, long hint);
6477
6478 struct filterops fs_filtops = {
6479 .f_isfd = 0,
6480 .f_attach = filt_fsattach,
6481 .f_detach = filt_fsdetach,
6482 .f_event = filt_fsevent
6483 };
6484
6485 static int
filt_fsattach(struct knote * kn)6486 filt_fsattach(struct knote *kn)
6487 {
6488
6489 kn->kn_flags |= EV_CLEAR;
6490 knlist_add(&fs_knlist, kn, 0);
6491 return (0);
6492 }
6493
6494 static void
filt_fsdetach(struct knote * kn)6495 filt_fsdetach(struct knote *kn)
6496 {
6497
6498 knlist_remove(&fs_knlist, kn, 0);
6499 }
6500
6501 static int
filt_fsevent(struct knote * kn,long hint)6502 filt_fsevent(struct knote *kn, long hint)
6503 {
6504
6505 kn->kn_fflags |= kn->kn_sfflags & hint;
6506
6507 return (kn->kn_fflags != 0);
6508 }
6509
6510 static int
sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)6511 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
6512 {
6513 struct vfsidctl vc;
6514 int error;
6515 struct mount *mp;
6516
6517 error = SYSCTL_IN(req, &vc, sizeof(vc));
6518 if (error)
6519 return (error);
6520 if (vc.vc_vers != VFS_CTL_VERS1)
6521 return (EINVAL);
6522 mp = vfs_getvfs(&vc.vc_fsid);
6523 if (mp == NULL)
6524 return (ENOENT);
6525 /* ensure that a specific sysctl goes to the right filesystem. */
6526 if (strcmp(vc.vc_fstypename, "*") != 0 &&
6527 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
6528 vfs_rel(mp);
6529 return (EINVAL);
6530 }
6531 VCTLTOREQ(&vc, req);
6532 error = VFS_SYSCTL(mp, vc.vc_op, req);
6533 vfs_rel(mp);
6534 return (error);
6535 }
6536
6537 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR,
6538 NULL, 0, sysctl_vfs_ctl, "",
6539 "Sysctl by fsid");
6540
6541 /*
6542 * Function to initialize a va_filerev field sensibly.
6543 * XXX: Wouldn't a random number make a lot more sense ??
6544 */
6545 u_quad_t
init_va_filerev(void)6546 init_va_filerev(void)
6547 {
6548 struct bintime bt;
6549
6550 getbinuptime(&bt);
6551 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
6552 }
6553
6554 static int filt_vfsread(struct knote *kn, long hint);
6555 static int filt_vfswrite(struct knote *kn, long hint);
6556 static int filt_vfsvnode(struct knote *kn, long hint);
6557 static void filt_vfsdetach(struct knote *kn);
6558 static struct filterops vfsread_filtops = {
6559 .f_isfd = 1,
6560 .f_detach = filt_vfsdetach,
6561 .f_event = filt_vfsread
6562 };
6563 static struct filterops vfswrite_filtops = {
6564 .f_isfd = 1,
6565 .f_detach = filt_vfsdetach,
6566 .f_event = filt_vfswrite
6567 };
6568 static struct filterops vfsvnode_filtops = {
6569 .f_isfd = 1,
6570 .f_detach = filt_vfsdetach,
6571 .f_event = filt_vfsvnode
6572 };
6573
6574 static void
vfs_knllock(void * arg)6575 vfs_knllock(void *arg)
6576 {
6577 struct vnode *vp = arg;
6578
6579 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
6580 }
6581
6582 static void
vfs_knlunlock(void * arg)6583 vfs_knlunlock(void *arg)
6584 {
6585 struct vnode *vp = arg;
6586
6587 VOP_UNLOCK(vp);
6588 }
6589
6590 static void
vfs_knl_assert_lock(void * arg,int what)6591 vfs_knl_assert_lock(void *arg, int what)
6592 {
6593 #ifdef DEBUG_VFS_LOCKS
6594 struct vnode *vp = arg;
6595
6596 if (what == LA_LOCKED)
6597 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
6598 else
6599 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
6600 #endif
6601 }
6602
6603 int
vfs_kqfilter(struct vop_kqfilter_args * ap)6604 vfs_kqfilter(struct vop_kqfilter_args *ap)
6605 {
6606 struct vnode *vp = ap->a_vp;
6607 struct knote *kn = ap->a_kn;
6608 struct knlist *knl;
6609
6610 KASSERT(vp->v_type != VFIFO || (kn->kn_filter != EVFILT_READ &&
6611 kn->kn_filter != EVFILT_WRITE),
6612 ("READ/WRITE filter on a FIFO leaked through"));
6613 switch (kn->kn_filter) {
6614 case EVFILT_READ:
6615 kn->kn_fop = &vfsread_filtops;
6616 break;
6617 case EVFILT_WRITE:
6618 kn->kn_fop = &vfswrite_filtops;
6619 break;
6620 case EVFILT_VNODE:
6621 kn->kn_fop = &vfsvnode_filtops;
6622 break;
6623 default:
6624 return (EINVAL);
6625 }
6626
6627 kn->kn_hook = (caddr_t)vp;
6628
6629 v_addpollinfo(vp);
6630 if (vp->v_pollinfo == NULL)
6631 return (ENOMEM);
6632 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
6633 vhold(vp);
6634 knlist_add(knl, kn, 0);
6635
6636 return (0);
6637 }
6638
6639 /*
6640 * Detach knote from vnode
6641 */
6642 static void
filt_vfsdetach(struct knote * kn)6643 filt_vfsdetach(struct knote *kn)
6644 {
6645 struct vnode *vp = (struct vnode *)kn->kn_hook;
6646
6647 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
6648 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
6649 vdrop(vp);
6650 }
6651
6652 /*ARGSUSED*/
6653 static int
filt_vfsread(struct knote * kn,long hint)6654 filt_vfsread(struct knote *kn, long hint)
6655 {
6656 struct vnode *vp = (struct vnode *)kn->kn_hook;
6657 off_t size;
6658 int res;
6659
6660 /*
6661 * filesystem is gone, so set the EOF flag and schedule
6662 * the knote for deletion.
6663 */
6664 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6665 VI_LOCK(vp);
6666 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6667 VI_UNLOCK(vp);
6668 return (1);
6669 }
6670
6671 if (vn_getsize_locked(vp, &size, curthread->td_ucred) != 0)
6672 return (0);
6673
6674 VI_LOCK(vp);
6675 kn->kn_data = size - kn->kn_fp->f_offset;
6676 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
6677 VI_UNLOCK(vp);
6678 return (res);
6679 }
6680
6681 /*ARGSUSED*/
6682 static int
filt_vfswrite(struct knote * kn,long hint)6683 filt_vfswrite(struct knote *kn, long hint)
6684 {
6685 struct vnode *vp = (struct vnode *)kn->kn_hook;
6686
6687 VI_LOCK(vp);
6688
6689 /*
6690 * filesystem is gone, so set the EOF flag and schedule
6691 * the knote for deletion.
6692 */
6693 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
6694 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6695
6696 kn->kn_data = 0;
6697 VI_UNLOCK(vp);
6698 return (1);
6699 }
6700
6701 static int
filt_vfsvnode(struct knote * kn,long hint)6702 filt_vfsvnode(struct knote *kn, long hint)
6703 {
6704 struct vnode *vp = (struct vnode *)kn->kn_hook;
6705 int res;
6706
6707 VI_LOCK(vp);
6708 if (kn->kn_sfflags & hint)
6709 kn->kn_fflags |= hint;
6710 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6711 kn->kn_flags |= EV_EOF;
6712 VI_UNLOCK(vp);
6713 return (1);
6714 }
6715 res = (kn->kn_fflags != 0);
6716 VI_UNLOCK(vp);
6717 return (res);
6718 }
6719
6720 int
vfs_read_dirent(struct vop_readdir_args * ap,struct dirent * dp,off_t off)6721 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
6722 {
6723 int error;
6724
6725 if (dp->d_reclen > ap->a_uio->uio_resid)
6726 return (ENAMETOOLONG);
6727 error = uiomove(dp, dp->d_reclen, ap->a_uio);
6728 if (error) {
6729 if (ap->a_ncookies != NULL) {
6730 if (ap->a_cookies != NULL)
6731 free(ap->a_cookies, M_TEMP);
6732 ap->a_cookies = NULL;
6733 *ap->a_ncookies = 0;
6734 }
6735 return (error);
6736 }
6737 if (ap->a_ncookies == NULL)
6738 return (0);
6739
6740 KASSERT(ap->a_cookies,
6741 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
6742
6743 *ap->a_cookies = realloc(*ap->a_cookies,
6744 (*ap->a_ncookies + 1) * sizeof(uint64_t), M_TEMP, M_WAITOK | M_ZERO);
6745 (*ap->a_cookies)[*ap->a_ncookies] = off;
6746 *ap->a_ncookies += 1;
6747 return (0);
6748 }
6749
6750 /*
6751 * The purpose of this routine is to remove granularity from accmode_t,
6752 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
6753 * VADMIN and VAPPEND.
6754 *
6755 * If it returns 0, the caller is supposed to continue with the usual
6756 * access checks using 'accmode' as modified by this routine. If it
6757 * returns nonzero value, the caller is supposed to return that value
6758 * as errno.
6759 *
6760 * Note that after this routine runs, accmode may be zero.
6761 */
6762 int
vfs_unixify_accmode(accmode_t * accmode)6763 vfs_unixify_accmode(accmode_t *accmode)
6764 {
6765 /*
6766 * There is no way to specify explicit "deny" rule using
6767 * file mode or POSIX.1e ACLs.
6768 */
6769 if (*accmode & VEXPLICIT_DENY) {
6770 *accmode = 0;
6771 return (0);
6772 }
6773
6774 /*
6775 * None of these can be translated into usual access bits.
6776 * Also, the common case for NFSv4 ACLs is to not contain
6777 * either of these bits. Caller should check for VWRITE
6778 * on the containing directory instead.
6779 */
6780 if (*accmode & (VDELETE_CHILD | VDELETE))
6781 return (EPERM);
6782
6783 if (*accmode & VADMIN_PERMS) {
6784 *accmode &= ~VADMIN_PERMS;
6785 *accmode |= VADMIN;
6786 }
6787
6788 /*
6789 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
6790 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
6791 */
6792 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
6793
6794 return (0);
6795 }
6796
6797 /*
6798 * Clear out a doomed vnode (if any) and replace it with a new one as long
6799 * as the fs is not being unmounted. Return the root vnode to the caller.
6800 */
6801 static int __noinline
vfs_cache_root_fallback(struct mount * mp,int flags,struct vnode ** vpp)6802 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp)
6803 {
6804 struct vnode *vp;
6805 int error;
6806
6807 restart:
6808 if (mp->mnt_rootvnode != NULL) {
6809 MNT_ILOCK(mp);
6810 vp = mp->mnt_rootvnode;
6811 if (vp != NULL) {
6812 if (!VN_IS_DOOMED(vp)) {
6813 vrefact(vp);
6814 MNT_IUNLOCK(mp);
6815 error = vn_lock(vp, flags);
6816 if (error == 0) {
6817 *vpp = vp;
6818 return (0);
6819 }
6820 vrele(vp);
6821 goto restart;
6822 }
6823 /*
6824 * Clear the old one.
6825 */
6826 mp->mnt_rootvnode = NULL;
6827 }
6828 MNT_IUNLOCK(mp);
6829 if (vp != NULL) {
6830 vfs_op_barrier_wait(mp);
6831 vrele(vp);
6832 }
6833 }
6834 error = VFS_CACHEDROOT(mp, flags, vpp);
6835 if (error != 0)
6836 return (error);
6837 if (mp->mnt_vfs_ops == 0) {
6838 MNT_ILOCK(mp);
6839 if (mp->mnt_vfs_ops != 0) {
6840 MNT_IUNLOCK(mp);
6841 return (0);
6842 }
6843 if (mp->mnt_rootvnode == NULL) {
6844 vrefact(*vpp);
6845 mp->mnt_rootvnode = *vpp;
6846 } else {
6847 if (mp->mnt_rootvnode != *vpp) {
6848 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) {
6849 panic("%s: mismatch between vnode returned "
6850 " by VFS_CACHEDROOT and the one cached "
6851 " (%p != %p)",
6852 __func__, *vpp, mp->mnt_rootvnode);
6853 }
6854 }
6855 }
6856 MNT_IUNLOCK(mp);
6857 }
6858 return (0);
6859 }
6860
6861 int
vfs_cache_root(struct mount * mp,int flags,struct vnode ** vpp)6862 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp)
6863 {
6864 struct mount_pcpu *mpcpu;
6865 struct vnode *vp;
6866 int error;
6867
6868 if (!vfs_op_thread_enter(mp, mpcpu))
6869 return (vfs_cache_root_fallback(mp, flags, vpp));
6870 vp = atomic_load_ptr(&mp->mnt_rootvnode);
6871 if (vp == NULL || VN_IS_DOOMED(vp)) {
6872 vfs_op_thread_exit(mp, mpcpu);
6873 return (vfs_cache_root_fallback(mp, flags, vpp));
6874 }
6875 vrefact(vp);
6876 vfs_op_thread_exit(mp, mpcpu);
6877 error = vn_lock(vp, flags);
6878 if (error != 0) {
6879 vrele(vp);
6880 return (vfs_cache_root_fallback(mp, flags, vpp));
6881 }
6882 *vpp = vp;
6883 return (0);
6884 }
6885
6886 struct vnode *
vfs_cache_root_clear(struct mount * mp)6887 vfs_cache_root_clear(struct mount *mp)
6888 {
6889 struct vnode *vp;
6890
6891 /*
6892 * ops > 0 guarantees there is nobody who can see this vnode
6893 */
6894 MPASS(mp->mnt_vfs_ops > 0);
6895 vp = mp->mnt_rootvnode;
6896 if (vp != NULL)
6897 vn_seqc_write_begin(vp);
6898 mp->mnt_rootvnode = NULL;
6899 return (vp);
6900 }
6901
6902 void
vfs_cache_root_set(struct mount * mp,struct vnode * vp)6903 vfs_cache_root_set(struct mount *mp, struct vnode *vp)
6904 {
6905
6906 MPASS(mp->mnt_vfs_ops > 0);
6907 vrefact(vp);
6908 mp->mnt_rootvnode = vp;
6909 }
6910
6911 /*
6912 * These are helper functions for filesystems to traverse all
6913 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
6914 *
6915 * This interface replaces MNT_VNODE_FOREACH.
6916 */
6917
6918 struct vnode *
__mnt_vnode_next_all(struct vnode ** mvp,struct mount * mp)6919 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
6920 {
6921 struct vnode *vp;
6922
6923 maybe_yield();
6924 MNT_ILOCK(mp);
6925 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6926 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL;
6927 vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
6928 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
6929 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
6930 continue;
6931 VI_LOCK(vp);
6932 if (VN_IS_DOOMED(vp)) {
6933 VI_UNLOCK(vp);
6934 continue;
6935 }
6936 break;
6937 }
6938 if (vp == NULL) {
6939 __mnt_vnode_markerfree_all(mvp, mp);
6940 /* MNT_IUNLOCK(mp); -- done in above function */
6941 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
6942 return (NULL);
6943 }
6944 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
6945 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
6946 MNT_IUNLOCK(mp);
6947 return (vp);
6948 }
6949
6950 struct vnode *
__mnt_vnode_first_all(struct vnode ** mvp,struct mount * mp)6951 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
6952 {
6953 struct vnode *vp;
6954
6955 *mvp = vn_alloc_marker(mp);
6956 MNT_ILOCK(mp);
6957 MNT_REF(mp);
6958
6959 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
6960 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
6961 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
6962 continue;
6963 VI_LOCK(vp);
6964 if (VN_IS_DOOMED(vp)) {
6965 VI_UNLOCK(vp);
6966 continue;
6967 }
6968 break;
6969 }
6970 if (vp == NULL) {
6971 MNT_REL(mp);
6972 MNT_IUNLOCK(mp);
6973 vn_free_marker(*mvp);
6974 *mvp = NULL;
6975 return (NULL);
6976 }
6977 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
6978 MNT_IUNLOCK(mp);
6979 return (vp);
6980 }
6981
6982 void
__mnt_vnode_markerfree_all(struct vnode ** mvp,struct mount * mp)6983 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
6984 {
6985
6986 if (*mvp == NULL) {
6987 MNT_IUNLOCK(mp);
6988 return;
6989 }
6990
6991 mtx_assert(MNT_MTX(mp), MA_OWNED);
6992
6993 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6994 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
6995 MNT_REL(mp);
6996 MNT_IUNLOCK(mp);
6997 vn_free_marker(*mvp);
6998 *mvp = NULL;
6999 }
7000
7001 /*
7002 * These are helper functions for filesystems to traverse their
7003 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h
7004 */
7005 static void
mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)7006 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
7007 {
7008
7009 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
7010
7011 MNT_ILOCK(mp);
7012 MNT_REL(mp);
7013 MNT_IUNLOCK(mp);
7014 vn_free_marker(*mvp);
7015 *mvp = NULL;
7016 }
7017
7018 /*
7019 * Relock the mp mount vnode list lock with the vp vnode interlock in the
7020 * conventional lock order during mnt_vnode_next_lazy iteration.
7021 *
7022 * On entry, the mount vnode list lock is held and the vnode interlock is not.
7023 * The list lock is dropped and reacquired. On success, both locks are held.
7024 * On failure, the mount vnode list lock is held but the vnode interlock is
7025 * not, and the procedure may have yielded.
7026 */
7027 static bool
mnt_vnode_next_lazy_relock(struct vnode * mvp,struct mount * mp,struct vnode * vp)7028 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp,
7029 struct vnode *vp)
7030 {
7031
7032 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER &&
7033 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp,
7034 ("%s: bad marker", __func__));
7035 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp,
7036 ("%s: inappropriate vnode", __func__));
7037 ASSERT_VI_UNLOCKED(vp, __func__);
7038 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
7039
7040 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist);
7041 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist);
7042
7043 /*
7044 * Note we may be racing against vdrop which transitioned the hold
7045 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine,
7046 * if we are the only user after we get the interlock we will just
7047 * vdrop.
7048 */
7049 vhold(vp);
7050 mtx_unlock(&mp->mnt_listmtx);
7051 VI_LOCK(vp);
7052 if (VN_IS_DOOMED(vp)) {
7053 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
7054 goto out_lost;
7055 }
7056 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
7057 /*
7058 * There is nothing to do if we are the last user.
7059 */
7060 if (!refcount_release_if_not_last(&vp->v_holdcnt))
7061 goto out_lost;
7062 mtx_lock(&mp->mnt_listmtx);
7063 return (true);
7064 out_lost:
7065 vdropl(vp);
7066 maybe_yield();
7067 mtx_lock(&mp->mnt_listmtx);
7068 return (false);
7069 }
7070
7071 static struct vnode *
mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7072 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7073 void *cbarg)
7074 {
7075 struct vnode *vp;
7076
7077 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
7078 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
7079 restart:
7080 vp = TAILQ_NEXT(*mvp, v_lazylist);
7081 while (vp != NULL) {
7082 if (vp->v_type == VMARKER) {
7083 vp = TAILQ_NEXT(vp, v_lazylist);
7084 continue;
7085 }
7086 /*
7087 * See if we want to process the vnode. Note we may encounter a
7088 * long string of vnodes we don't care about and hog the list
7089 * as a result. Check for it and requeue the marker.
7090 */
7091 VNPASS(!VN_IS_DOOMED(vp), vp);
7092 if (!cb(vp, cbarg)) {
7093 if (!should_yield()) {
7094 vp = TAILQ_NEXT(vp, v_lazylist);
7095 continue;
7096 }
7097 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp,
7098 v_lazylist);
7099 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp,
7100 v_lazylist);
7101 mtx_unlock(&mp->mnt_listmtx);
7102 kern_yield(PRI_USER);
7103 mtx_lock(&mp->mnt_listmtx);
7104 goto restart;
7105 }
7106 /*
7107 * Try-lock because this is the wrong lock order.
7108 */
7109 if (!VI_TRYLOCK(vp) &&
7110 !mnt_vnode_next_lazy_relock(*mvp, mp, vp))
7111 goto restart;
7112 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
7113 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
7114 ("alien vnode on the lazy list %p %p", vp, mp));
7115 VNPASS(vp->v_mount == mp, vp);
7116 VNPASS(!VN_IS_DOOMED(vp), vp);
7117 break;
7118 }
7119 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7120
7121 /* Check if we are done */
7122 if (vp == NULL) {
7123 mtx_unlock(&mp->mnt_listmtx);
7124 mnt_vnode_markerfree_lazy(mvp, mp);
7125 return (NULL);
7126 }
7127 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist);
7128 mtx_unlock(&mp->mnt_listmtx);
7129 ASSERT_VI_LOCKED(vp, "lazy iter");
7130 return (vp);
7131 }
7132
7133 struct vnode *
__mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7134 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7135 void *cbarg)
7136 {
7137
7138 maybe_yield();
7139 mtx_lock(&mp->mnt_listmtx);
7140 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7141 }
7142
7143 struct vnode *
__mnt_vnode_first_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7144 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7145 void *cbarg)
7146 {
7147 struct vnode *vp;
7148
7149 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist))
7150 return (NULL);
7151
7152 *mvp = vn_alloc_marker(mp);
7153 MNT_ILOCK(mp);
7154 MNT_REF(mp);
7155 MNT_IUNLOCK(mp);
7156
7157 mtx_lock(&mp->mnt_listmtx);
7158 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist);
7159 if (vp == NULL) {
7160 mtx_unlock(&mp->mnt_listmtx);
7161 mnt_vnode_markerfree_lazy(mvp, mp);
7162 return (NULL);
7163 }
7164 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist);
7165 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7166 }
7167
7168 void
__mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)7169 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
7170 {
7171
7172 if (*mvp == NULL)
7173 return;
7174
7175 mtx_lock(&mp->mnt_listmtx);
7176 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7177 mtx_unlock(&mp->mnt_listmtx);
7178 mnt_vnode_markerfree_lazy(mvp, mp);
7179 }
7180
7181 int
vn_dir_check_exec(struct vnode * vp,struct componentname * cnp)7182 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp)
7183 {
7184
7185 if ((cnp->cn_flags & NOEXECCHECK) != 0) {
7186 cnp->cn_flags &= ~NOEXECCHECK;
7187 return (0);
7188 }
7189
7190 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, curthread));
7191 }
7192
7193 /*
7194 * Do not use this variant unless you have means other than the hold count
7195 * to prevent the vnode from getting freed.
7196 */
7197 void
vn_seqc_write_begin_locked(struct vnode * vp)7198 vn_seqc_write_begin_locked(struct vnode *vp)
7199 {
7200
7201 ASSERT_VI_LOCKED(vp, __func__);
7202 VNPASS(vp->v_holdcnt > 0, vp);
7203 VNPASS(vp->v_seqc_users >= 0, vp);
7204 vp->v_seqc_users++;
7205 if (vp->v_seqc_users == 1)
7206 seqc_sleepable_write_begin(&vp->v_seqc);
7207 }
7208
7209 void
vn_seqc_write_begin(struct vnode * vp)7210 vn_seqc_write_begin(struct vnode *vp)
7211 {
7212
7213 VI_LOCK(vp);
7214 vn_seqc_write_begin_locked(vp);
7215 VI_UNLOCK(vp);
7216 }
7217
7218 void
vn_seqc_write_end_locked(struct vnode * vp)7219 vn_seqc_write_end_locked(struct vnode *vp)
7220 {
7221
7222 ASSERT_VI_LOCKED(vp, __func__);
7223 VNPASS(vp->v_seqc_users > 0, vp);
7224 vp->v_seqc_users--;
7225 if (vp->v_seqc_users == 0)
7226 seqc_sleepable_write_end(&vp->v_seqc);
7227 }
7228
7229 void
vn_seqc_write_end(struct vnode * vp)7230 vn_seqc_write_end(struct vnode *vp)
7231 {
7232
7233 VI_LOCK(vp);
7234 vn_seqc_write_end_locked(vp);
7235 VI_UNLOCK(vp);
7236 }
7237
7238 /*
7239 * Special case handling for allocating and freeing vnodes.
7240 *
7241 * The counter remains unchanged on free so that a doomed vnode will
7242 * keep testing as in modify as long as it is accessible with SMR.
7243 */
7244 static void
vn_seqc_init(struct vnode * vp)7245 vn_seqc_init(struct vnode *vp)
7246 {
7247
7248 vp->v_seqc = 0;
7249 vp->v_seqc_users = 0;
7250 }
7251
7252 static void
vn_seqc_write_end_free(struct vnode * vp)7253 vn_seqc_write_end_free(struct vnode *vp)
7254 {
7255
7256 VNPASS(seqc_in_modify(vp->v_seqc), vp);
7257 VNPASS(vp->v_seqc_users == 1, vp);
7258 }
7259
7260 void
vn_irflag_set_locked(struct vnode * vp,short toset)7261 vn_irflag_set_locked(struct vnode *vp, short toset)
7262 {
7263 short flags;
7264
7265 ASSERT_VI_LOCKED(vp, __func__);
7266 flags = vn_irflag_read(vp);
7267 VNASSERT((flags & toset) == 0, vp,
7268 ("%s: some of the passed flags already set (have %d, passed %d)\n",
7269 __func__, flags, toset));
7270 atomic_store_short(&vp->v_irflag, flags | toset);
7271 }
7272
7273 void
vn_irflag_set(struct vnode * vp,short toset)7274 vn_irflag_set(struct vnode *vp, short toset)
7275 {
7276
7277 VI_LOCK(vp);
7278 vn_irflag_set_locked(vp, toset);
7279 VI_UNLOCK(vp);
7280 }
7281
7282 void
vn_irflag_set_cond_locked(struct vnode * vp,short toset)7283 vn_irflag_set_cond_locked(struct vnode *vp, short toset)
7284 {
7285 short flags;
7286
7287 ASSERT_VI_LOCKED(vp, __func__);
7288 flags = vn_irflag_read(vp);
7289 atomic_store_short(&vp->v_irflag, flags | toset);
7290 }
7291
7292 void
vn_irflag_set_cond(struct vnode * vp,short toset)7293 vn_irflag_set_cond(struct vnode *vp, short toset)
7294 {
7295
7296 VI_LOCK(vp);
7297 vn_irflag_set_cond_locked(vp, toset);
7298 VI_UNLOCK(vp);
7299 }
7300
7301 void
vn_irflag_unset_locked(struct vnode * vp,short tounset)7302 vn_irflag_unset_locked(struct vnode *vp, short tounset)
7303 {
7304 short flags;
7305
7306 ASSERT_VI_LOCKED(vp, __func__);
7307 flags = vn_irflag_read(vp);
7308 VNASSERT((flags & tounset) == tounset, vp,
7309 ("%s: some of the passed flags not set (have %d, passed %d)\n",
7310 __func__, flags, tounset));
7311 atomic_store_short(&vp->v_irflag, flags & ~tounset);
7312 }
7313
7314 void
vn_irflag_unset(struct vnode * vp,short tounset)7315 vn_irflag_unset(struct vnode *vp, short tounset)
7316 {
7317
7318 VI_LOCK(vp);
7319 vn_irflag_unset_locked(vp, tounset);
7320 VI_UNLOCK(vp);
7321 }
7322
7323 int
vn_getsize_locked(struct vnode * vp,off_t * size,struct ucred * cred)7324 vn_getsize_locked(struct vnode *vp, off_t *size, struct ucred *cred)
7325 {
7326 struct vattr vattr;
7327 int error;
7328
7329 ASSERT_VOP_LOCKED(vp, __func__);
7330 error = VOP_GETATTR(vp, &vattr, cred);
7331 if (__predict_true(error == 0)) {
7332 if (vattr.va_size <= OFF_MAX)
7333 *size = vattr.va_size;
7334 else
7335 error = EFBIG;
7336 }
7337 return (error);
7338 }
7339
7340 int
vn_getsize(struct vnode * vp,off_t * size,struct ucred * cred)7341 vn_getsize(struct vnode *vp, off_t *size, struct ucred *cred)
7342 {
7343 int error;
7344
7345 VOP_LOCK(vp, LK_SHARED);
7346 error = vn_getsize_locked(vp, size, cred);
7347 VOP_UNLOCK(vp);
7348 return (error);
7349 }
7350
7351 #ifdef INVARIANTS
7352 void
vn_set_state_validate(struct vnode * vp,__enum_uint8 (vstate)state)7353 vn_set_state_validate(struct vnode *vp, __enum_uint8(vstate) state)
7354 {
7355
7356 switch (vp->v_state) {
7357 case VSTATE_UNINITIALIZED:
7358 switch (state) {
7359 case VSTATE_CONSTRUCTED:
7360 case VSTATE_DESTROYING:
7361 return;
7362 default:
7363 break;
7364 }
7365 break;
7366 case VSTATE_CONSTRUCTED:
7367 ASSERT_VOP_ELOCKED(vp, __func__);
7368 switch (state) {
7369 case VSTATE_DESTROYING:
7370 return;
7371 default:
7372 break;
7373 }
7374 break;
7375 case VSTATE_DESTROYING:
7376 ASSERT_VOP_ELOCKED(vp, __func__);
7377 switch (state) {
7378 case VSTATE_DEAD:
7379 return;
7380 default:
7381 break;
7382 }
7383 break;
7384 case VSTATE_DEAD:
7385 switch (state) {
7386 case VSTATE_UNINITIALIZED:
7387 return;
7388 default:
7389 break;
7390 }
7391 break;
7392 }
7393
7394 vn_printf(vp, "invalid state transition %d -> %d\n", vp->v_state, state);
7395 panic("invalid state transition %d -> %d\n", vp->v_state, state);
7396 }
7397 #endif
7398