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/user.h>
83 #include <sys/vmmeter.h>
84 #include <sys/vnode.h>
85 #include <sys/watchdog.h>
86
87 #include <machine/stdarg.h>
88
89 #include <security/mac/mac_framework.h>
90
91 #include <vm/vm.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_extern.h>
94 #include <vm/pmap.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_page.h>
97 #include <vm/vm_kern.h>
98 #include <vm/vnode_pager.h>
99 #include <vm/uma.h>
100
101 #if defined(DEBUG_VFS_LOCKS) && (!defined(INVARIANTS) || !defined(WITNESS))
102 #error DEBUG_VFS_LOCKS requires INVARIANTS and WITNESS
103 #endif
104
105 #ifdef DDB
106 #include <ddb/ddb.h>
107 #endif
108
109 static void delmntque(struct vnode *vp);
110 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
111 int slpflag, int slptimeo);
112 static void syncer_shutdown(void *arg, int howto);
113 static int vtryrecycle(struct vnode *vp, bool isvnlru);
114 static void v_init_counters(struct vnode *);
115 static void vn_seqc_init(struct vnode *);
116 static void vn_seqc_write_end_free(struct vnode *vp);
117 static void vgonel(struct vnode *);
118 static bool vhold_recycle_free(struct vnode *);
119 static void vdropl_recycle(struct vnode *vp);
120 static void vdrop_recycle(struct vnode *vp);
121 static void vfs_knllock(void *arg);
122 static void vfs_knlunlock(void *arg);
123 static void vfs_knl_assert_lock(void *arg, int what);
124 static void destroy_vpollinfo(struct vpollinfo *vi);
125 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
126 daddr_t startlbn, daddr_t endlbn);
127 static void vnlru_recalc(void);
128
129 static SYSCTL_NODE(_vfs, OID_AUTO, vnode, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
130 "vnode configuration and statistics");
131 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, param, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
132 "vnode configuration");
133 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, stats, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
134 "vnode statistics");
135 static SYSCTL_NODE(_vfs_vnode, OID_AUTO, vnlru, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
136 "vnode recycling");
137
138 /*
139 * Number of vnodes in existence. Increased whenever getnewvnode()
140 * allocates a new vnode, decreased in vdropl() for VIRF_DOOMED vnode.
141 */
142 static u_long __exclusive_cache_line numvnodes;
143
144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
145 "Number of vnodes in existence (legacy)");
146 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, count, CTLFLAG_RD, &numvnodes, 0,
147 "Number of vnodes in existence");
148
149 static counter_u64_t vnodes_created;
150 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
151 "Number of vnodes created by getnewvnode (legacy)");
152 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, created, CTLFLAG_RD, &vnodes_created,
153 "Number of vnodes created by getnewvnode");
154
155 /*
156 * Conversion tables for conversion from vnode types to inode formats
157 * and back.
158 */
159 __enum_uint8(vtype) iftovt_tab[16] = {
160 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
161 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
162 };
163 int vttoif_tab[10] = {
164 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
165 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
166 };
167
168 /*
169 * List of allocates vnodes in the system.
170 */
171 static TAILQ_HEAD(freelst, vnode) vnode_list;
172 static struct vnode *vnode_list_free_marker;
173 static struct vnode *vnode_list_reclaim_marker;
174
175 /*
176 * "Free" vnode target. Free vnodes are rarely completely free, but are
177 * just ones that are cheap to recycle. Usually they are for files which
178 * have been stat'd but not read; these usually have inode and namecache
179 * data attached to them. This target is the preferred minimum size of a
180 * sub-cache consisting mostly of such files. The system balances the size
181 * of this sub-cache with its complement to try to prevent either from
182 * thrashing while the other is relatively inactive. The targets express
183 * a preference for the best balance.
184 *
185 * "Above" this target there are 2 further targets (watermarks) related
186 * to recyling of free vnodes. In the best-operating case, the cache is
187 * exactly full, the free list has size between vlowat and vhiwat above the
188 * free target, and recycling from it and normal use maintains this state.
189 * Sometimes the free list is below vlowat or even empty, but this state
190 * is even better for immediate use provided the cache is not full.
191 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
192 * ones) to reach one of these states. The watermarks are currently hard-
193 * coded as 4% and 9% of the available space higher. These and the default
194 * of 25% for wantfreevnodes are too large if the memory size is large.
195 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
196 * whenever vnlru_proc() becomes active.
197 */
198 static long wantfreevnodes;
199 static long __exclusive_cache_line freevnodes;
200 static long freevnodes_old;
201
202 static u_long recycles_count;
203 SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS, &recycles_count, 0,
204 "Number of vnodes recycled to meet vnode cache targets (legacy)");
205 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles, CTLFLAG_RD | CTLFLAG_STATS,
206 &recycles_count, 0,
207 "Number of vnodes recycled to meet vnode cache targets");
208
209 static u_long recycles_free_count;
210 SYSCTL_ULONG(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS,
211 &recycles_free_count, 0,
212 "Number of free vnodes recycled to meet vnode cache targets (legacy)");
213 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, recycles_free, CTLFLAG_RD | CTLFLAG_STATS,
214 &recycles_free_count, 0,
215 "Number of free vnodes recycled to meet vnode cache targets");
216
217 static counter_u64_t direct_recycles_free_count;
218 SYSCTL_COUNTER_U64(_vfs_vnode_vnlru, OID_AUTO, direct_recycles_free, CTLFLAG_RD,
219 &direct_recycles_free_count,
220 "Number of free vnodes recycled by vn_alloc callers to meet vnode cache targets");
221
222 static counter_u64_t vnode_skipped_requeues;
223 SYSCTL_COUNTER_U64(_vfs_vnode_stats, OID_AUTO, skipped_requeues, CTLFLAG_RD, &vnode_skipped_requeues,
224 "Number of times LRU requeue was skipped due to lock contention");
225
226 static __read_mostly bool vnode_can_skip_requeue;
227 SYSCTL_BOOL(_vfs_vnode_param, OID_AUTO, can_skip_requeue, CTLFLAG_RW,
228 &vnode_can_skip_requeue, 0, "Is LRU requeue skippable");
229
230 static u_long deferred_inact;
231 SYSCTL_ULONG(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD,
232 &deferred_inact, 0, "Number of times inactive processing was deferred");
233
234 /* To keep more than one thread at a time from running vfs_getnewfsid */
235 static struct mtx mntid_mtx;
236
237 /*
238 * Lock for any access to the following:
239 * vnode_list
240 * numvnodes
241 * freevnodes
242 */
243 static struct mtx __exclusive_cache_line vnode_list_mtx;
244
245 /* Publicly exported FS */
246 struct nfs_public nfs_pub;
247
248 static uma_zone_t buf_trie_zone;
249 static smr_t buf_trie_smr;
250
251 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
252 static uma_zone_t vnode_zone;
253 MALLOC_DEFINE(M_VNODEPOLL, "VN POLL", "vnode poll");
254
255 __read_frequently smr_t vfs_smr;
256
257 /*
258 * The workitem queue.
259 *
260 * It is useful to delay writes of file data and filesystem metadata
261 * for tens of seconds so that quickly created and deleted files need
262 * not waste disk bandwidth being created and removed. To realize this,
263 * we append vnodes to a "workitem" queue. When running with a soft
264 * updates implementation, most pending metadata dependencies should
265 * not wait for more than a few seconds. Thus, mounted on block devices
266 * are delayed only about a half the time that file data is delayed.
267 * Similarly, directory updates are more critical, so are only delayed
268 * about a third the time that file data is delayed. Thus, there are
269 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
270 * one each second (driven off the filesystem syncer process). The
271 * syncer_delayno variable indicates the next queue that is to be processed.
272 * Items that need to be processed soon are placed in this queue:
273 *
274 * syncer_workitem_pending[syncer_delayno]
275 *
276 * A delay of fifteen seconds is done by placing the request fifteen
277 * entries later in the queue:
278 *
279 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
280 *
281 */
282 static int syncer_delayno;
283 static long syncer_mask;
284 LIST_HEAD(synclist, bufobj);
285 static struct synclist *syncer_workitem_pending;
286 /*
287 * The sync_mtx protects:
288 * bo->bo_synclist
289 * sync_vnode_count
290 * syncer_delayno
291 * syncer_state
292 * syncer_workitem_pending
293 * syncer_worklist_len
294 * rushjob
295 */
296 static struct mtx sync_mtx;
297 static struct cv sync_wakeup;
298
299 #define SYNCER_MAXDELAY 32
300 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
301 static int syncdelay = 30; /* max time to delay syncing data */
302 static int filedelay = 30; /* time to delay syncing files */
303 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
304 "Time to delay syncing files (in seconds)");
305 static int dirdelay = 29; /* time to delay syncing directories */
306 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
307 "Time to delay syncing directories (in seconds)");
308 static int metadelay = 28; /* time to delay syncing metadata */
309 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
310 "Time to delay syncing metadata (in seconds)");
311 static int rushjob; /* number of slots to run ASAP */
312 static int stat_rush_requests; /* number of times I/O speeded up */
313 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
314 "Number of times I/O speeded up (rush requests)");
315
316 #define VDBATCH_SIZE 8
317 struct vdbatch {
318 u_int index;
319 struct mtx lock;
320 struct vnode *tab[VDBATCH_SIZE];
321 };
322 DPCPU_DEFINE_STATIC(struct vdbatch, vd);
323
324 static void vdbatch_dequeue(struct vnode *vp);
325
326 /*
327 * The syncer will require at least SYNCER_MAXDELAY iterations to shutdown;
328 * we probably don't want to pause for the whole second each time.
329 */
330 #define SYNCER_SHUTDOWN_SPEEDUP 32
331 static int sync_vnode_count;
332 static int syncer_worklist_len;
333 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
334 syncer_state;
335
336 /* Target for maximum number of vnodes. */
337 u_long desiredvnodes;
338 static u_long gapvnodes; /* gap between wanted and desired */
339 static u_long vhiwat; /* enough extras after expansion */
340 static u_long vlowat; /* minimal extras before expansion */
341 static bool vstir; /* nonzero to stir non-free vnodes */
342 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
343
344 static u_long vnlru_read_freevnodes(void);
345
346 /*
347 * Note that no attempt is made to sanitize these parameters.
348 */
349 static int
sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)350 sysctl_maxvnodes(SYSCTL_HANDLER_ARGS)
351 {
352 u_long val;
353 int error;
354
355 val = desiredvnodes;
356 error = sysctl_handle_long(oidp, &val, 0, req);
357 if (error != 0 || req->newptr == NULL)
358 return (error);
359
360 if (val == desiredvnodes)
361 return (0);
362 mtx_lock(&vnode_list_mtx);
363 desiredvnodes = val;
364 wantfreevnodes = desiredvnodes / 4;
365 vnlru_recalc();
366 mtx_unlock(&vnode_list_mtx);
367 /*
368 * XXX There is no protection against multiple threads changing
369 * desiredvnodes at the same time. Locking above only helps vnlru and
370 * getnewvnode.
371 */
372 vfs_hash_changesize(desiredvnodes);
373 cache_changesize(desiredvnodes);
374 return (0);
375 }
376
377 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
378 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
379 "LU", "Target for maximum number of vnodes (legacy)");
380 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, limit,
381 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_maxvnodes,
382 "LU", "Target for maximum number of vnodes");
383
384 static int
sysctl_freevnodes(SYSCTL_HANDLER_ARGS)385 sysctl_freevnodes(SYSCTL_HANDLER_ARGS)
386 {
387 u_long rfreevnodes;
388
389 rfreevnodes = vnlru_read_freevnodes();
390 return (sysctl_handle_long(oidp, &rfreevnodes, 0, req));
391 }
392
393 SYSCTL_PROC(_vfs, OID_AUTO, freevnodes,
394 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
395 "LU", "Number of \"free\" vnodes (legacy)");
396 SYSCTL_PROC(_vfs_vnode_stats, OID_AUTO, free,
397 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RD, NULL, 0, sysctl_freevnodes,
398 "LU", "Number of \"free\" vnodes");
399
400 static int
sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)401 sysctl_wantfreevnodes(SYSCTL_HANDLER_ARGS)
402 {
403 u_long val;
404 int error;
405
406 val = wantfreevnodes;
407 error = sysctl_handle_long(oidp, &val, 0, req);
408 if (error != 0 || req->newptr == NULL)
409 return (error);
410
411 if (val == wantfreevnodes)
412 return (0);
413 mtx_lock(&vnode_list_mtx);
414 wantfreevnodes = val;
415 vnlru_recalc();
416 mtx_unlock(&vnode_list_mtx);
417 return (0);
418 }
419
420 SYSCTL_PROC(_vfs, OID_AUTO, wantfreevnodes,
421 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
422 "LU", "Target for minimum number of \"free\" vnodes (legacy)");
423 SYSCTL_PROC(_vfs_vnode_param, OID_AUTO, wantfree,
424 CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0, sysctl_wantfreevnodes,
425 "LU", "Target for minimum number of \"free\" vnodes");
426
427 static int vnlru_nowhere;
428 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, failed_runs, CTLFLAG_RD | CTLFLAG_STATS,
429 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
430
431 static int
sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)432 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
433 {
434 struct vnode *vp;
435 struct nameidata nd;
436 char *buf;
437 unsigned long ndflags;
438 int error;
439
440 if (req->newptr == NULL)
441 return (EINVAL);
442 if (req->newlen >= PATH_MAX)
443 return (E2BIG);
444
445 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK);
446 error = SYSCTL_IN(req, buf, req->newlen);
447 if (error != 0)
448 goto out;
449
450 buf[req->newlen] = '\0';
451
452 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1;
453 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf);
454 if ((error = namei(&nd)) != 0)
455 goto out;
456 vp = nd.ni_vp;
457
458 if (VN_IS_DOOMED(vp)) {
459 /*
460 * This vnode is being recycled. Return != 0 to let the caller
461 * know that the sysctl had no effect. Return EAGAIN because a
462 * subsequent call will likely succeed (since namei will create
463 * a new vnode if necessary)
464 */
465 error = EAGAIN;
466 goto putvnode;
467 }
468
469 vgone(vp);
470 putvnode:
471 vput(vp);
472 NDFREE_PNBUF(&nd);
473 out:
474 free(buf, M_TEMP);
475 return (error);
476 }
477
478 static int
sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)479 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)
480 {
481 struct thread *td = curthread;
482 struct vnode *vp;
483 struct file *fp;
484 int error;
485 int fd;
486
487 if (req->newptr == NULL)
488 return (EBADF);
489
490 error = sysctl_handle_int(oidp, &fd, 0, req);
491 if (error != 0)
492 return (error);
493 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp);
494 if (error != 0)
495 return (error);
496 vp = fp->f_vnode;
497
498 error = vn_lock(vp, LK_EXCLUSIVE);
499 if (error != 0)
500 goto drop;
501
502 vgone(vp);
503 VOP_UNLOCK(vp);
504 drop:
505 fdrop(fp, td);
506 return (error);
507 }
508
509 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
510 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
511 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
512 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode,
513 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
514 sysctl_ftry_reclaim_vnode, "I",
515 "Try to reclaim a vnode by its file descriptor");
516
517 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
518 #define vnsz2log 8
519 #ifndef DEBUG_LOCKS
520 _Static_assert(sizeof(struct vnode) >= 1UL << vnsz2log &&
521 sizeof(struct vnode) < 1UL << (vnsz2log + 1),
522 "vnsz2log needs to be updated");
523 #endif
524
525 /*
526 * Support for the bufobj clean & dirty pctrie.
527 */
528 static void *
buf_trie_alloc(struct pctrie * ptree)529 buf_trie_alloc(struct pctrie *ptree)
530 {
531 return (uma_zalloc_smr(buf_trie_zone, M_NOWAIT));
532 }
533
534 static void
buf_trie_free(struct pctrie * ptree,void * node)535 buf_trie_free(struct pctrie *ptree, void *node)
536 {
537 uma_zfree_smr(buf_trie_zone, node);
538 }
539 PCTRIE_DEFINE_SMR(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free,
540 buf_trie_smr);
541
542 /*
543 * Lookup the next element greater than or equal to lblkno, accounting for the
544 * fact that, for pctries, negative values are greater than nonnegative ones.
545 */
546 static struct buf *
buf_lookup_ge(struct bufv * bv,daddr_t lblkno)547 buf_lookup_ge(struct bufv *bv, daddr_t lblkno)
548 {
549 struct buf *bp;
550
551 bp = BUF_PCTRIE_LOOKUP_GE(&bv->bv_root, lblkno);
552 if (bp == NULL && lblkno < 0)
553 bp = BUF_PCTRIE_LOOKUP_GE(&bv->bv_root, 0);
554 if (bp != NULL && bp->b_lblkno < lblkno)
555 bp = NULL;
556 return (bp);
557 }
558
559 /*
560 * Insert bp, and find the next element smaller than bp, accounting for the fact
561 * that, for pctries, negative values are greater than nonnegative ones.
562 */
563 static int
buf_insert_lookup_le(struct bufv * bv,struct buf * bp,struct buf ** n)564 buf_insert_lookup_le(struct bufv *bv, struct buf *bp, struct buf **n)
565 {
566 int error;
567
568 error = BUF_PCTRIE_INSERT_LOOKUP_LE(&bv->bv_root, bp, n);
569 if (error != EEXIST) {
570 if (*n == NULL && bp->b_lblkno >= 0)
571 *n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, ~0L);
572 if (*n != NULL && (*n)->b_lblkno >= bp->b_lblkno)
573 *n = NULL;
574 }
575 return (error);
576 }
577
578 /*
579 * Initialize the vnode management data structures.
580 *
581 * Reevaluate the following cap on the number of vnodes after the physical
582 * memory size exceeds 512GB. In the limit, as the physical memory size
583 * grows, the ratio of the memory size in KB to vnodes approaches 64:1.
584 */
585 #ifndef MAXVNODES_MAX
586 #define MAXVNODES_MAX (512UL * 1024 * 1024 / 64) /* 8M */
587 #endif
588
589 static MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
590
591 static struct vnode *
vn_alloc_marker(struct mount * mp)592 vn_alloc_marker(struct mount *mp)
593 {
594 struct vnode *vp;
595
596 vp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
597 vp->v_type = VMARKER;
598 vp->v_mount = mp;
599
600 return (vp);
601 }
602
603 static void
vn_free_marker(struct vnode * vp)604 vn_free_marker(struct vnode *vp)
605 {
606
607 MPASS(vp->v_type == VMARKER);
608 free(vp, M_VNODE_MARKER);
609 }
610
611 #ifdef KASAN
612 static int
vnode_ctor(void * mem,int size,void * arg __unused,int flags __unused)613 vnode_ctor(void *mem, int size, void *arg __unused, int flags __unused)
614 {
615 kasan_mark(mem, size, roundup2(size, UMA_ALIGN_PTR + 1), 0);
616 return (0);
617 }
618
619 static void
vnode_dtor(void * mem,int size,void * arg __unused)620 vnode_dtor(void *mem, int size, void *arg __unused)
621 {
622 size_t end1, end2, off1, off2;
623
624 _Static_assert(offsetof(struct vnode, v_vnodelist) <
625 offsetof(struct vnode, v_dbatchcpu),
626 "KASAN marks require updating");
627
628 off1 = offsetof(struct vnode, v_vnodelist);
629 off2 = offsetof(struct vnode, v_dbatchcpu);
630 end1 = off1 + sizeof(((struct vnode *)NULL)->v_vnodelist);
631 end2 = off2 + sizeof(((struct vnode *)NULL)->v_dbatchcpu);
632
633 /*
634 * Access to the v_vnodelist and v_dbatchcpu fields are permitted even
635 * after the vnode has been freed. Try to get some KASAN coverage by
636 * marking everything except those two fields as invalid. Because
637 * KASAN's tracking is not byte-granular, any preceding fields sharing
638 * the same 8-byte aligned word must also be marked valid.
639 */
640
641 /* Handle the area from the start until v_vnodelist... */
642 off1 = rounddown2(off1, KASAN_SHADOW_SCALE);
643 kasan_mark(mem, off1, off1, KASAN_UMA_FREED);
644
645 /* ... then the area between v_vnodelist and v_dbatchcpu ... */
646 off1 = roundup2(end1, KASAN_SHADOW_SCALE);
647 off2 = rounddown2(off2, KASAN_SHADOW_SCALE);
648 if (off2 > off1)
649 kasan_mark((void *)((char *)mem + off1), off2 - off1,
650 off2 - off1, KASAN_UMA_FREED);
651
652 /* ... and finally the area from v_dbatchcpu to the end. */
653 off2 = roundup2(end2, KASAN_SHADOW_SCALE);
654 kasan_mark((void *)((char *)mem + off2), size - off2, size - off2,
655 KASAN_UMA_FREED);
656 }
657 #endif /* KASAN */
658
659 /*
660 * Initialize a vnode as it first enters the zone.
661 */
662 static int
vnode_init(void * mem,int size,int flags)663 vnode_init(void *mem, int size, int flags)
664 {
665 struct vnode *vp;
666
667 vp = mem;
668 bzero(vp, size);
669 /*
670 * Setup locks.
671 */
672 vp->v_vnlock = &vp->v_lock;
673 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
674 /*
675 * By default, don't allow shared locks unless filesystems opt-in.
676 */
677 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
678 LK_NOSHARE | LK_IS_VNODE);
679 /*
680 * Initialize bufobj.
681 */
682 bufobj_init(&vp->v_bufobj, vp);
683 /*
684 * Initialize namecache.
685 */
686 cache_vnode_init(vp);
687 /*
688 * Initialize rangelocks.
689 */
690 rangelock_init(&vp->v_rl);
691
692 vp->v_dbatchcpu = NOCPU;
693
694 vp->v_state = VSTATE_DEAD;
695
696 /*
697 * Check vhold_recycle_free for an explanation.
698 */
699 vp->v_holdcnt = VHOLD_NO_SMR;
700 vp->v_type = VNON;
701 mtx_lock(&vnode_list_mtx);
702 TAILQ_INSERT_BEFORE(vnode_list_free_marker, vp, v_vnodelist);
703 mtx_unlock(&vnode_list_mtx);
704 return (0);
705 }
706
707 /*
708 * Free a vnode when it is cleared from the zone.
709 */
710 static void
vnode_fini(void * mem,int size)711 vnode_fini(void *mem, int size)
712 {
713 struct vnode *vp;
714 struct bufobj *bo;
715
716 vp = mem;
717 vdbatch_dequeue(vp);
718 mtx_lock(&vnode_list_mtx);
719 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
720 mtx_unlock(&vnode_list_mtx);
721 rangelock_destroy(&vp->v_rl);
722 lockdestroy(vp->v_vnlock);
723 mtx_destroy(&vp->v_interlock);
724 bo = &vp->v_bufobj;
725 rw_destroy(BO_LOCKPTR(bo));
726
727 kasan_mark(mem, size, size, 0);
728 }
729
730 /*
731 * Provide the size of NFS nclnode and NFS fh for calculation of the
732 * vnode memory consumption. The size is specified directly to
733 * eliminate dependency on NFS-private header.
734 *
735 * Other filesystems may use bigger or smaller (like UFS and ZFS)
736 * private inode data, but the NFS-based estimation is ample enough.
737 * Still, we care about differences in the size between 64- and 32-bit
738 * platforms.
739 *
740 * Namecache structure size is heuristically
741 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
742 */
743 #ifdef _LP64
744 #define NFS_NCLNODE_SZ (528 + 64)
745 #define NC_SZ 148
746 #else
747 #define NFS_NCLNODE_SZ (360 + 32)
748 #define NC_SZ 92
749 #endif
750
751 static void
vntblinit(void * dummy __unused)752 vntblinit(void *dummy __unused)
753 {
754 struct vdbatch *vd;
755 uma_ctor ctor;
756 uma_dtor dtor;
757 int cpu, physvnodes, virtvnodes;
758
759 /*
760 * Desiredvnodes is a function of the physical memory size and the
761 * kernel's heap size. Generally speaking, it scales with the
762 * physical memory size. The ratio of desiredvnodes to the physical
763 * memory size is 1:16 until desiredvnodes exceeds 98,304.
764 * Thereafter, the
765 * marginal ratio of desiredvnodes to the physical memory size is
766 * 1:64. However, desiredvnodes is limited by the kernel's heap
767 * size. The memory required by desiredvnodes vnodes and vm objects
768 * must not exceed 1/10th of the kernel's heap size.
769 */
770 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
771 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
772 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
773 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
774 desiredvnodes = min(physvnodes, virtvnodes);
775 if (desiredvnodes > MAXVNODES_MAX) {
776 if (bootverbose)
777 printf("Reducing kern.maxvnodes %lu -> %lu\n",
778 desiredvnodes, MAXVNODES_MAX);
779 desiredvnodes = MAXVNODES_MAX;
780 }
781 wantfreevnodes = desiredvnodes / 4;
782 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
783 TAILQ_INIT(&vnode_list);
784 mtx_init(&vnode_list_mtx, "vnode_list", NULL, MTX_DEF);
785 /*
786 * The lock is taken to appease WITNESS.
787 */
788 mtx_lock(&vnode_list_mtx);
789 vnlru_recalc();
790 mtx_unlock(&vnode_list_mtx);
791 vnode_list_free_marker = vn_alloc_marker(NULL);
792 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_free_marker, v_vnodelist);
793 vnode_list_reclaim_marker = vn_alloc_marker(NULL);
794 TAILQ_INSERT_HEAD(&vnode_list, vnode_list_reclaim_marker, v_vnodelist);
795
796 #ifdef KASAN
797 ctor = vnode_ctor;
798 dtor = vnode_dtor;
799 #else
800 ctor = NULL;
801 dtor = NULL;
802 #endif
803 vnode_zone = uma_zcreate("VNODE", sizeof(struct vnode), ctor, dtor,
804 vnode_init, vnode_fini, UMA_ALIGN_PTR, UMA_ZONE_NOKASAN);
805 uma_zone_set_smr(vnode_zone, vfs_smr);
806
807 /*
808 * Preallocate enough nodes to support one-per buf so that
809 * we can not fail an insert. reassignbuf() callers can not
810 * tolerate the insertion failure.
811 */
812 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
813 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
814 UMA_ZONE_NOFREE | UMA_ZONE_SMR);
815 buf_trie_smr = uma_zone_get_smr(buf_trie_zone);
816 uma_prealloc(buf_trie_zone, nbuf);
817
818 vnodes_created = counter_u64_alloc(M_WAITOK);
819 direct_recycles_free_count = counter_u64_alloc(M_WAITOK);
820 vnode_skipped_requeues = counter_u64_alloc(M_WAITOK);
821
822 /*
823 * Initialize the filesystem syncer.
824 */
825 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
826 &syncer_mask);
827 syncer_maxdelay = syncer_mask + 1;
828 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
829 cv_init(&sync_wakeup, "syncer");
830
831 CPU_FOREACH(cpu) {
832 vd = DPCPU_ID_PTR((cpu), vd);
833 bzero(vd, sizeof(*vd));
834 mtx_init(&vd->lock, "vdbatch", NULL, MTX_DEF);
835 }
836 }
837 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
838
839 /*
840 * Mark a mount point as busy. Used to synchronize access and to delay
841 * unmounting. Eventually, mountlist_mtx is not released on failure.
842 *
843 * vfs_busy() is a custom lock, it can block the caller.
844 * vfs_busy() only sleeps if the unmount is active on the mount point.
845 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
846 * vnode belonging to mp.
847 *
848 * Lookup uses vfs_busy() to traverse mount points.
849 * root fs var fs
850 * / vnode lock A / vnode lock (/var) D
851 * /var vnode lock B /log vnode lock(/var/log) E
852 * vfs_busy lock C vfs_busy lock F
853 *
854 * Within each file system, the lock order is C->A->B and F->D->E.
855 *
856 * When traversing across mounts, the system follows that lock order:
857 *
858 * C->A->B
859 * |
860 * +->F->D->E
861 *
862 * The lookup() process for namei("/var") illustrates the process:
863 * 1. VOP_LOOKUP() obtains B while A is held
864 * 2. vfs_busy() obtains a shared lock on F while A and B are held
865 * 3. vput() releases lock on B
866 * 4. vput() releases lock on A
867 * 5. VFS_ROOT() obtains lock on D while shared lock on F is held
868 * 6. vfs_unbusy() releases shared lock on F
869 * 7. vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
870 * Attempt to lock A (instead of vp_crossmp) while D is held would
871 * violate the global order, causing deadlocks.
872 *
873 * dounmount() locks B while F is drained. Note that for stacked
874 * filesystems, D and B in the example above may be the same lock,
875 * which introdues potential lock order reversal deadlock between
876 * dounmount() and step 5 above. These filesystems may avoid the LOR
877 * by setting VV_CROSSLOCK on the covered vnode so that lock B will
878 * remain held until after step 5.
879 */
880 int
vfs_busy(struct mount * mp,int flags)881 vfs_busy(struct mount *mp, int flags)
882 {
883 struct mount_pcpu *mpcpu;
884
885 MPASS((flags & ~MBF_MASK) == 0);
886 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
887
888 if (vfs_op_thread_enter(mp, mpcpu)) {
889 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
890 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0);
891 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0);
892 vfs_mp_count_add_pcpu(mpcpu, ref, 1);
893 vfs_mp_count_add_pcpu(mpcpu, lockref, 1);
894 vfs_op_thread_exit(mp, mpcpu);
895 if (flags & MBF_MNTLSTLOCK)
896 mtx_unlock(&mountlist_mtx);
897 return (0);
898 }
899
900 MNT_ILOCK(mp);
901 vfs_assert_mount_counters(mp);
902 MNT_REF(mp);
903 /*
904 * If mount point is currently being unmounted, sleep until the
905 * mount point fate is decided. If thread doing the unmounting fails,
906 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
907 * that this mount point has survived the unmount attempt and vfs_busy
908 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
909 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
910 * about to be really destroyed. vfs_busy needs to release its
911 * reference on the mount point in this case and return with ENOENT,
912 * telling the caller the mount it tried to busy is no longer valid.
913 */
914 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
915 KASSERT(TAILQ_EMPTY(&mp->mnt_uppers),
916 ("%s: non-empty upper mount list with pending unmount",
917 __func__));
918 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
919 MNT_REL(mp);
920 MNT_IUNLOCK(mp);
921 CTR1(KTR_VFS, "%s: failed busying before sleeping",
922 __func__);
923 return (ENOENT);
924 }
925 if (flags & MBF_MNTLSTLOCK)
926 mtx_unlock(&mountlist_mtx);
927 mp->mnt_kern_flag |= MNTK_MWAIT;
928 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
929 if (flags & MBF_MNTLSTLOCK)
930 mtx_lock(&mountlist_mtx);
931 MNT_ILOCK(mp);
932 }
933 if (flags & MBF_MNTLSTLOCK)
934 mtx_unlock(&mountlist_mtx);
935 mp->mnt_lockref++;
936 MNT_IUNLOCK(mp);
937 return (0);
938 }
939
940 /*
941 * Free a busy filesystem.
942 */
943 void
vfs_unbusy(struct mount * mp)944 vfs_unbusy(struct mount *mp)
945 {
946 struct mount_pcpu *mpcpu;
947 int c;
948
949 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
950
951 if (vfs_op_thread_enter(mp, mpcpu)) {
952 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
953 vfs_mp_count_sub_pcpu(mpcpu, lockref, 1);
954 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
955 vfs_op_thread_exit(mp, mpcpu);
956 return;
957 }
958
959 MNT_ILOCK(mp);
960 vfs_assert_mount_counters(mp);
961 MNT_REL(mp);
962 c = --mp->mnt_lockref;
963 if (mp->mnt_vfs_ops == 0) {
964 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
965 MNT_IUNLOCK(mp);
966 return;
967 }
968 if (c < 0)
969 vfs_dump_mount_counters(mp);
970 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
971 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
972 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
973 mp->mnt_kern_flag &= ~MNTK_DRAINING;
974 wakeup(&mp->mnt_lockref);
975 }
976 MNT_IUNLOCK(mp);
977 }
978
979 /*
980 * Lookup a mount point by filesystem identifier.
981 */
982 struct mount *
vfs_getvfs(fsid_t * fsid)983 vfs_getvfs(fsid_t *fsid)
984 {
985 struct mount *mp;
986
987 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
988 mtx_lock(&mountlist_mtx);
989 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
990 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
991 vfs_ref(mp);
992 mtx_unlock(&mountlist_mtx);
993 return (mp);
994 }
995 }
996 mtx_unlock(&mountlist_mtx);
997 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
998 return ((struct mount *) 0);
999 }
1000
1001 /*
1002 * Lookup a mount point by filesystem identifier, busying it before
1003 * returning.
1004 *
1005 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
1006 * cache for popular filesystem identifiers. The cache is lockess, using
1007 * the fact that struct mount's are never freed. In worst case we may
1008 * get pointer to unmounted or even different filesystem, so we have to
1009 * check what we got, and go slow way if so.
1010 */
1011 struct mount *
vfs_busyfs(fsid_t * fsid)1012 vfs_busyfs(fsid_t *fsid)
1013 {
1014 #define FSID_CACHE_SIZE 256
1015 typedef struct mount * volatile vmp_t;
1016 static vmp_t cache[FSID_CACHE_SIZE];
1017 struct mount *mp;
1018 int error;
1019 uint32_t hash;
1020
1021 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
1022 hash = fsid->val[0] ^ fsid->val[1];
1023 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
1024 mp = cache[hash];
1025 if (mp == NULL || fsidcmp(&mp->mnt_stat.f_fsid, fsid) != 0)
1026 goto slow;
1027 if (vfs_busy(mp, 0) != 0) {
1028 cache[hash] = NULL;
1029 goto slow;
1030 }
1031 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0)
1032 return (mp);
1033 else
1034 vfs_unbusy(mp);
1035
1036 slow:
1037 mtx_lock(&mountlist_mtx);
1038 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
1039 if (fsidcmp(&mp->mnt_stat.f_fsid, fsid) == 0) {
1040 error = vfs_busy(mp, MBF_MNTLSTLOCK);
1041 if (error) {
1042 cache[hash] = NULL;
1043 mtx_unlock(&mountlist_mtx);
1044 return (NULL);
1045 }
1046 cache[hash] = mp;
1047 return (mp);
1048 }
1049 }
1050 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
1051 mtx_unlock(&mountlist_mtx);
1052 return ((struct mount *) 0);
1053 }
1054
1055 /*
1056 * Check if a user can access privileged mount options.
1057 */
1058 int
vfs_suser(struct mount * mp,struct thread * td)1059 vfs_suser(struct mount *mp, struct thread *td)
1060 {
1061 int error;
1062
1063 if (jailed(td->td_ucred)) {
1064 /*
1065 * If the jail of the calling thread lacks permission for
1066 * this type of file system, deny immediately.
1067 */
1068 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag))
1069 return (EPERM);
1070
1071 /*
1072 * If the file system was mounted outside the jail of the
1073 * calling thread, deny immediately.
1074 */
1075 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
1076 return (EPERM);
1077 }
1078
1079 /*
1080 * If file system supports delegated administration, we don't check
1081 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
1082 * by the file system itself.
1083 * If this is not the user that did original mount, we check for
1084 * the PRIV_VFS_MOUNT_OWNER privilege.
1085 */
1086 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
1087 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
1088 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
1089 return (error);
1090 }
1091 return (0);
1092 }
1093
1094 /*
1095 * Get a new unique fsid. Try to make its val[0] unique, since this value
1096 * will be used to create fake device numbers for stat(). Also try (but
1097 * not so hard) make its val[0] unique mod 2^16, since some emulators only
1098 * support 16-bit device numbers. We end up with unique val[0]'s for the
1099 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
1100 *
1101 * Keep in mind that several mounts may be running in parallel. Starting
1102 * the search one past where the previous search terminated is both a
1103 * micro-optimization and a defense against returning the same fsid to
1104 * different mounts.
1105 */
1106 void
vfs_getnewfsid(struct mount * mp)1107 vfs_getnewfsid(struct mount *mp)
1108 {
1109 static uint16_t mntid_base;
1110 struct mount *nmp;
1111 fsid_t tfsid;
1112 int mtype;
1113
1114 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
1115 mtx_lock(&mntid_mtx);
1116 mtype = mp->mnt_vfc->vfc_typenum;
1117 tfsid.val[1] = mtype;
1118 mtype = (mtype & 0xFF) << 24;
1119 for (;;) {
1120 tfsid.val[0] = makedev(255,
1121 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
1122 mntid_base++;
1123 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
1124 break;
1125 vfs_rel(nmp);
1126 }
1127 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
1128 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
1129 mtx_unlock(&mntid_mtx);
1130 }
1131
1132 /*
1133 * Knob to control the precision of file timestamps:
1134 *
1135 * 0 = seconds only; nanoseconds zeroed.
1136 * 1 = seconds and nanoseconds, accurate within 1/HZ.
1137 * 2 = seconds and nanoseconds, truncated to microseconds.
1138 * >=3 = seconds and nanoseconds, maximum precision.
1139 */
1140 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
1141
1142 static int timestamp_precision = TSP_USEC;
1143 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
1144 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
1145 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, "
1146 "3+: sec + ns (max. precision))");
1147
1148 /*
1149 * Get a current timestamp.
1150 */
1151 void
vfs_timestamp(struct timespec * tsp)1152 vfs_timestamp(struct timespec *tsp)
1153 {
1154 struct timeval tv;
1155
1156 switch (timestamp_precision) {
1157 case TSP_SEC:
1158 tsp->tv_sec = time_second;
1159 tsp->tv_nsec = 0;
1160 break;
1161 case TSP_HZ:
1162 getnanotime(tsp);
1163 break;
1164 case TSP_USEC:
1165 microtime(&tv);
1166 TIMEVAL_TO_TIMESPEC(&tv, tsp);
1167 break;
1168 case TSP_NSEC:
1169 default:
1170 nanotime(tsp);
1171 break;
1172 }
1173 }
1174
1175 /*
1176 * Set vnode attributes to VNOVAL
1177 */
1178 void
vattr_null(struct vattr * vap)1179 vattr_null(struct vattr *vap)
1180 {
1181
1182 vap->va_type = VNON;
1183 vap->va_size = VNOVAL;
1184 vap->va_bytes = VNOVAL;
1185 vap->va_mode = VNOVAL;
1186 vap->va_nlink = VNOVAL;
1187 vap->va_uid = VNOVAL;
1188 vap->va_gid = VNOVAL;
1189 vap->va_fsid = VNOVAL;
1190 vap->va_fileid = VNOVAL;
1191 vap->va_blocksize = VNOVAL;
1192 vap->va_rdev = VNOVAL;
1193 vap->va_atime.tv_sec = VNOVAL;
1194 vap->va_atime.tv_nsec = VNOVAL;
1195 vap->va_mtime.tv_sec = VNOVAL;
1196 vap->va_mtime.tv_nsec = VNOVAL;
1197 vap->va_ctime.tv_sec = VNOVAL;
1198 vap->va_ctime.tv_nsec = VNOVAL;
1199 vap->va_birthtime.tv_sec = VNOVAL;
1200 vap->va_birthtime.tv_nsec = VNOVAL;
1201 vap->va_flags = VNOVAL;
1202 vap->va_gen = VNOVAL;
1203 vap->va_vaflags = 0;
1204 vap->va_filerev = VNOVAL;
1205 }
1206
1207 /*
1208 * Try to reduce the total number of vnodes.
1209 *
1210 * This routine (and its user) are buggy in at least the following ways:
1211 * - all parameters were picked years ago when RAM sizes were significantly
1212 * smaller
1213 * - it can pick vnodes based on pages used by the vm object, but filesystems
1214 * like ZFS don't use it making the pick broken
1215 * - since ZFS has its own aging policy it gets partially combated by this one
1216 * - a dedicated method should be provided for filesystems to let them decide
1217 * whether the vnode should be recycled
1218 *
1219 * This routine is called when we have too many vnodes. It attempts
1220 * to free <count> vnodes and will potentially free vnodes that still
1221 * have VM backing store (VM backing store is typically the cause
1222 * of a vnode blowout so we want to do this). Therefore, this operation
1223 * is not considered cheap.
1224 *
1225 * A number of conditions may prevent a vnode from being reclaimed.
1226 * the buffer cache may have references on the vnode, a directory
1227 * vnode may still have references due to the namei cache representing
1228 * underlying files, or the vnode may be in active use. It is not
1229 * desirable to reuse such vnodes. These conditions may cause the
1230 * number of vnodes to reach some minimum value regardless of what
1231 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
1232 *
1233 * @param reclaim_nc_src Only reclaim directories with outgoing namecache
1234 * entries if this argument is strue
1235 * @param trigger Only reclaim vnodes with fewer than this many resident
1236 * pages.
1237 * @param target How many vnodes to reclaim.
1238 * @return The number of vnodes that were reclaimed.
1239 */
1240 static int
vlrureclaim(bool reclaim_nc_src,int trigger,u_long target)1241 vlrureclaim(bool reclaim_nc_src, int trigger, u_long target)
1242 {
1243 struct vnode *vp, *mvp;
1244 struct mount *mp;
1245 struct vm_object *object;
1246 u_long done;
1247 bool retried;
1248
1249 mtx_assert(&vnode_list_mtx, MA_OWNED);
1250
1251 retried = false;
1252 done = 0;
1253
1254 mvp = vnode_list_reclaim_marker;
1255 restart:
1256 vp = mvp;
1257 while (done < target) {
1258 vp = TAILQ_NEXT(vp, v_vnodelist);
1259 if (__predict_false(vp == NULL))
1260 break;
1261
1262 if (__predict_false(vp->v_type == VMARKER))
1263 continue;
1264
1265 /*
1266 * If it's been deconstructed already, it's still
1267 * referenced, or it exceeds the trigger, skip it.
1268 * Also skip free vnodes. We are trying to make space
1269 * for more free vnodes, not reduce their count.
1270 */
1271 if (vp->v_usecount > 0 || vp->v_holdcnt == 0 ||
1272 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)))
1273 goto next_iter;
1274
1275 if (vp->v_type == VBAD || vp->v_type == VNON)
1276 goto next_iter;
1277
1278 object = atomic_load_ptr(&vp->v_object);
1279 if (object == NULL || object->resident_page_count > trigger) {
1280 goto next_iter;
1281 }
1282
1283 /*
1284 * Handle races against vnode allocation. Filesystems lock the
1285 * vnode some time after it gets returned from getnewvnode,
1286 * despite type and hold count being manipulated earlier.
1287 * Resorting to checking v_mount restores guarantees present
1288 * before the global list was reworked to contain all vnodes.
1289 */
1290 if (!VI_TRYLOCK(vp))
1291 goto next_iter;
1292 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1293 VI_UNLOCK(vp);
1294 goto next_iter;
1295 }
1296 if (vp->v_mount == NULL) {
1297 VI_UNLOCK(vp);
1298 goto next_iter;
1299 }
1300 vholdl(vp);
1301 VI_UNLOCK(vp);
1302 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1303 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1304 mtx_unlock(&vnode_list_mtx);
1305
1306 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
1307 vdrop_recycle(vp);
1308 goto next_iter_unlocked;
1309 }
1310 if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) {
1311 vdrop_recycle(vp);
1312 vn_finished_write(mp);
1313 goto next_iter_unlocked;
1314 }
1315
1316 VI_LOCK(vp);
1317 if (vp->v_usecount > 0 ||
1318 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1319 (vp->v_object != NULL && vp->v_object->handle == vp &&
1320 vp->v_object->resident_page_count > trigger)) {
1321 VOP_UNLOCK(vp);
1322 vdropl_recycle(vp);
1323 vn_finished_write(mp);
1324 goto next_iter_unlocked;
1325 }
1326 recycles_count++;
1327 vgonel(vp);
1328 VOP_UNLOCK(vp);
1329 vdropl_recycle(vp);
1330 vn_finished_write(mp);
1331 done++;
1332 next_iter_unlocked:
1333 maybe_yield();
1334 mtx_lock(&vnode_list_mtx);
1335 goto restart;
1336 next_iter:
1337 MPASS(vp->v_type != VMARKER);
1338 if (!should_yield())
1339 continue;
1340 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1341 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1342 mtx_unlock(&vnode_list_mtx);
1343 kern_yield(PRI_USER);
1344 mtx_lock(&vnode_list_mtx);
1345 goto restart;
1346 }
1347 if (done == 0 && !retried) {
1348 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1349 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1350 retried = true;
1351 goto restart;
1352 }
1353 return (done);
1354 }
1355
1356 static int max_free_per_call = 10000;
1357 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_free_per_call, 0,
1358 "limit on vnode free requests per call to the vnlru_free routine (legacy)");
1359 SYSCTL_INT(_vfs_vnode_vnlru, OID_AUTO, max_free_per_call, CTLFLAG_RW,
1360 &max_free_per_call, 0,
1361 "limit on vnode free requests per call to the vnlru_free routine");
1362
1363 /*
1364 * Attempt to recycle requested amount of free vnodes.
1365 */
1366 static int
vnlru_free_impl(int count,struct vfsops * mnt_op,struct vnode * mvp,bool isvnlru)1367 vnlru_free_impl(int count, struct vfsops *mnt_op, struct vnode *mvp, bool isvnlru)
1368 {
1369 struct vnode *vp;
1370 struct mount *mp;
1371 int ocount;
1372 bool retried;
1373
1374 mtx_assert(&vnode_list_mtx, MA_OWNED);
1375 if (count > max_free_per_call)
1376 count = max_free_per_call;
1377 if (count == 0) {
1378 mtx_unlock(&vnode_list_mtx);
1379 return (0);
1380 }
1381 ocount = count;
1382 retried = false;
1383 vp = mvp;
1384 for (;;) {
1385 vp = TAILQ_NEXT(vp, v_vnodelist);
1386 if (__predict_false(vp == NULL)) {
1387 /*
1388 * The free vnode marker can be past eligible vnodes:
1389 * 1. if vdbatch_process trylock failed
1390 * 2. if vtryrecycle failed
1391 *
1392 * If so, start the scan from scratch.
1393 */
1394 if (!retried && vnlru_read_freevnodes() > 0) {
1395 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1396 TAILQ_INSERT_HEAD(&vnode_list, mvp, v_vnodelist);
1397 vp = mvp;
1398 retried = true;
1399 continue;
1400 }
1401
1402 /*
1403 * Give up
1404 */
1405 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1406 TAILQ_INSERT_TAIL(&vnode_list, mvp, v_vnodelist);
1407 mtx_unlock(&vnode_list_mtx);
1408 break;
1409 }
1410 if (__predict_false(vp->v_type == VMARKER))
1411 continue;
1412 if (vp->v_holdcnt > 0)
1413 continue;
1414 /*
1415 * Don't recycle if our vnode is from different type
1416 * of mount point. Note that mp is type-safe, the
1417 * check does not reach unmapped address even if
1418 * vnode is reclaimed.
1419 */
1420 if (mnt_op != NULL && (mp = vp->v_mount) != NULL &&
1421 mp->mnt_op != mnt_op) {
1422 continue;
1423 }
1424 if (__predict_false(vp->v_type == VBAD || vp->v_type == VNON)) {
1425 continue;
1426 }
1427 if (!vhold_recycle_free(vp))
1428 continue;
1429 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1430 TAILQ_INSERT_AFTER(&vnode_list, vp, mvp, v_vnodelist);
1431 mtx_unlock(&vnode_list_mtx);
1432 /*
1433 * FIXME: ignores the return value, meaning it may be nothing
1434 * got recycled but it claims otherwise to the caller.
1435 *
1436 * Originally the value started being ignored in 2005 with
1437 * 114a1006a8204aa156e1f9ad6476cdff89cada7f .
1438 *
1439 * Respecting the value can run into significant stalls if most
1440 * vnodes belong to one file system and it has writes
1441 * suspended. In presence of many threads and millions of
1442 * vnodes they keep contending on the vnode_list_mtx lock only
1443 * to find vnodes they can't recycle.
1444 *
1445 * The solution would be to pre-check if the vnode is likely to
1446 * be recycle-able, but it needs to happen with the
1447 * vnode_list_mtx lock held. This runs into a problem where
1448 * VOP_GETWRITEMOUNT (currently needed to find out about if
1449 * writes are frozen) can take locks which LOR against it.
1450 *
1451 * Check nullfs for one example (null_getwritemount).
1452 */
1453 vtryrecycle(vp, isvnlru);
1454 count--;
1455 if (count == 0) {
1456 break;
1457 }
1458 mtx_lock(&vnode_list_mtx);
1459 vp = mvp;
1460 }
1461 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1462 return (ocount - count);
1463 }
1464
1465 /*
1466 * XXX: returns without vnode_list_mtx locked!
1467 */
1468 static int
vnlru_free_locked_direct(int count)1469 vnlru_free_locked_direct(int count)
1470 {
1471 int ret;
1472
1473 mtx_assert(&vnode_list_mtx, MA_OWNED);
1474 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, false);
1475 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1476 return (ret);
1477 }
1478
1479 static int
vnlru_free_locked_vnlru(int count)1480 vnlru_free_locked_vnlru(int count)
1481 {
1482 int ret;
1483
1484 mtx_assert(&vnode_list_mtx, MA_OWNED);
1485 ret = vnlru_free_impl(count, NULL, vnode_list_free_marker, true);
1486 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1487 return (ret);
1488 }
1489
1490 static int
vnlru_free_vnlru(int count)1491 vnlru_free_vnlru(int count)
1492 {
1493
1494 mtx_lock(&vnode_list_mtx);
1495 return (vnlru_free_locked_vnlru(count));
1496 }
1497
1498 void
vnlru_free_vfsops(int count,struct vfsops * mnt_op,struct vnode * mvp)1499 vnlru_free_vfsops(int count, struct vfsops *mnt_op, struct vnode *mvp)
1500 {
1501
1502 MPASS(mnt_op != NULL);
1503 MPASS(mvp != NULL);
1504 VNPASS(mvp->v_type == VMARKER, mvp);
1505 mtx_lock(&vnode_list_mtx);
1506 vnlru_free_impl(count, mnt_op, mvp, true);
1507 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1508 }
1509
1510 struct vnode *
vnlru_alloc_marker(void)1511 vnlru_alloc_marker(void)
1512 {
1513 struct vnode *mvp;
1514
1515 mvp = vn_alloc_marker(NULL);
1516 mtx_lock(&vnode_list_mtx);
1517 TAILQ_INSERT_BEFORE(vnode_list_free_marker, mvp, v_vnodelist);
1518 mtx_unlock(&vnode_list_mtx);
1519 return (mvp);
1520 }
1521
1522 void
vnlru_free_marker(struct vnode * mvp)1523 vnlru_free_marker(struct vnode *mvp)
1524 {
1525 mtx_lock(&vnode_list_mtx);
1526 TAILQ_REMOVE(&vnode_list, mvp, v_vnodelist);
1527 mtx_unlock(&vnode_list_mtx);
1528 vn_free_marker(mvp);
1529 }
1530
1531 static void
vnlru_recalc(void)1532 vnlru_recalc(void)
1533 {
1534
1535 mtx_assert(&vnode_list_mtx, MA_OWNED);
1536 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1537 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1538 vlowat = vhiwat / 2;
1539 }
1540
1541 /*
1542 * Attempt to recycle vnodes in a context that is always safe to block.
1543 * Calling vlrurecycle() from the bowels of filesystem code has some
1544 * interesting deadlock problems.
1545 */
1546 static struct proc *vnlruproc;
1547 static int vnlruproc_sig;
1548 static u_long vnlruproc_kicks;
1549
1550 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, kicks, CTLFLAG_RD, &vnlruproc_kicks, 0,
1551 "Number of times vnlru awakened due to vnode shortage");
1552
1553 #define VNLRU_COUNT_SLOP 100
1554
1555 /*
1556 * The main freevnodes counter is only updated when a counter local to CPU
1557 * diverges from 0 by more than VNLRU_FREEVNODES_SLOP. CPUs are conditionally
1558 * walked to compute a more accurate total.
1559 *
1560 * Note: the actual value at any given moment can still exceed slop, but it
1561 * should not be by significant margin in practice.
1562 */
1563 #define VNLRU_FREEVNODES_SLOP 126
1564
1565 static void __noinline
vfs_freevnodes_rollup(int8_t * lfreevnodes)1566 vfs_freevnodes_rollup(int8_t *lfreevnodes)
1567 {
1568
1569 atomic_add_long(&freevnodes, *lfreevnodes);
1570 *lfreevnodes = 0;
1571 critical_exit();
1572 }
1573
1574 static __inline void
vfs_freevnodes_inc(void)1575 vfs_freevnodes_inc(void)
1576 {
1577 int8_t *lfreevnodes;
1578
1579 critical_enter();
1580 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1581 (*lfreevnodes)++;
1582 if (__predict_false(*lfreevnodes == VNLRU_FREEVNODES_SLOP))
1583 vfs_freevnodes_rollup(lfreevnodes);
1584 else
1585 critical_exit();
1586 }
1587
1588 static __inline void
vfs_freevnodes_dec(void)1589 vfs_freevnodes_dec(void)
1590 {
1591 int8_t *lfreevnodes;
1592
1593 critical_enter();
1594 lfreevnodes = PCPU_PTR(vfs_freevnodes);
1595 (*lfreevnodes)--;
1596 if (__predict_false(*lfreevnodes == -VNLRU_FREEVNODES_SLOP))
1597 vfs_freevnodes_rollup(lfreevnodes);
1598 else
1599 critical_exit();
1600 }
1601
1602 static u_long
vnlru_read_freevnodes(void)1603 vnlru_read_freevnodes(void)
1604 {
1605 long slop, rfreevnodes, rfreevnodes_old;
1606 int cpu;
1607
1608 rfreevnodes = atomic_load_long(&freevnodes);
1609 rfreevnodes_old = atomic_load_long(&freevnodes_old);
1610
1611 if (rfreevnodes > rfreevnodes_old)
1612 slop = rfreevnodes - rfreevnodes_old;
1613 else
1614 slop = rfreevnodes_old - rfreevnodes;
1615 if (slop < VNLRU_FREEVNODES_SLOP)
1616 return (rfreevnodes >= 0 ? rfreevnodes : 0);
1617 CPU_FOREACH(cpu) {
1618 rfreevnodes += cpuid_to_pcpu[cpu]->pc_vfs_freevnodes;
1619 }
1620 atomic_store_long(&freevnodes_old, rfreevnodes);
1621 return (freevnodes_old >= 0 ? freevnodes_old : 0);
1622 }
1623
1624 static bool
vnlru_under(u_long rnumvnodes,u_long limit)1625 vnlru_under(u_long rnumvnodes, u_long limit)
1626 {
1627 u_long rfreevnodes, space;
1628
1629 if (__predict_false(rnumvnodes > desiredvnodes))
1630 return (true);
1631
1632 space = desiredvnodes - rnumvnodes;
1633 if (space < limit) {
1634 rfreevnodes = vnlru_read_freevnodes();
1635 if (rfreevnodes > wantfreevnodes)
1636 space += rfreevnodes - wantfreevnodes;
1637 }
1638 return (space < limit);
1639 }
1640
1641 static void
vnlru_kick_locked(void)1642 vnlru_kick_locked(void)
1643 {
1644
1645 mtx_assert(&vnode_list_mtx, MA_OWNED);
1646 if (vnlruproc_sig == 0) {
1647 vnlruproc_sig = 1;
1648 vnlruproc_kicks++;
1649 wakeup(vnlruproc);
1650 }
1651 }
1652
1653 static void
vnlru_kick_cond(void)1654 vnlru_kick_cond(void)
1655 {
1656
1657 if (vnlru_read_freevnodes() > wantfreevnodes)
1658 return;
1659
1660 if (vnlruproc_sig)
1661 return;
1662 mtx_lock(&vnode_list_mtx);
1663 vnlru_kick_locked();
1664 mtx_unlock(&vnode_list_mtx);
1665 }
1666
1667 static void
vnlru_proc_sleep(void)1668 vnlru_proc_sleep(void)
1669 {
1670
1671 if (vnlruproc_sig) {
1672 vnlruproc_sig = 0;
1673 wakeup(&vnlruproc_sig);
1674 }
1675 msleep(vnlruproc, &vnode_list_mtx, PVFS|PDROP, "vlruwt", hz);
1676 }
1677
1678 /*
1679 * A lighter version of the machinery below.
1680 *
1681 * Tries to reach goals only by recycling free vnodes and does not invoke
1682 * uma_reclaim(UMA_RECLAIM_DRAIN).
1683 *
1684 * This works around pathological behavior in vnlru in presence of tons of free
1685 * vnodes, but without having to rewrite the machinery at this time. Said
1686 * behavior boils down to continuously trying to reclaim all kinds of vnodes
1687 * (cycling through all levels of "force") when the count is transiently above
1688 * limit. This happens a lot when all vnodes are used up and vn_alloc
1689 * speculatively increments the counter.
1690 *
1691 * Sample testcase: vnode limit 8388608, 20 separate directory trees each with
1692 * 1 million files in total and 20 find(1) processes stating them in parallel
1693 * (one per each tree).
1694 *
1695 * On a kernel with only stock machinery this needs anywhere between 60 and 120
1696 * seconds to execute (time varies *wildly* between runs). With the workaround
1697 * it consistently stays around 20 seconds [it got further down with later
1698 * changes].
1699 *
1700 * That is to say the entire thing needs a fundamental redesign (most notably
1701 * to accommodate faster recycling), the above only tries to get it ouf the way.
1702 *
1703 * Return values are:
1704 * -1 -- fallback to regular vnlru loop
1705 * 0 -- do nothing, go to sleep
1706 * >0 -- recycle this many vnodes
1707 */
1708 static long
vnlru_proc_light_pick(void)1709 vnlru_proc_light_pick(void)
1710 {
1711 u_long rnumvnodes, rfreevnodes;
1712
1713 if (vstir || vnlruproc_sig == 1)
1714 return (-1);
1715
1716 rnumvnodes = atomic_load_long(&numvnodes);
1717 rfreevnodes = vnlru_read_freevnodes();
1718
1719 /*
1720 * vnode limit might have changed and now we may be at a significant
1721 * excess. Bail if we can't sort it out with free vnodes.
1722 *
1723 * Due to atomic updates the count can legitimately go above
1724 * the limit for a short period, don't bother doing anything in
1725 * that case.
1726 */
1727 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP + 10) {
1728 if (rnumvnodes - rfreevnodes >= desiredvnodes ||
1729 rfreevnodes <= wantfreevnodes) {
1730 return (-1);
1731 }
1732
1733 return (rnumvnodes - desiredvnodes);
1734 }
1735
1736 /*
1737 * Don't try to reach wantfreevnodes target if there are too few vnodes
1738 * to begin with.
1739 */
1740 if (rnumvnodes < wantfreevnodes) {
1741 return (0);
1742 }
1743
1744 if (rfreevnodes < wantfreevnodes) {
1745 return (-1);
1746 }
1747
1748 return (0);
1749 }
1750
1751 static bool
vnlru_proc_light(void)1752 vnlru_proc_light(void)
1753 {
1754 long freecount;
1755
1756 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1757
1758 freecount = vnlru_proc_light_pick();
1759 if (freecount == -1)
1760 return (false);
1761
1762 if (freecount != 0) {
1763 vnlru_free_vnlru(freecount);
1764 }
1765
1766 mtx_lock(&vnode_list_mtx);
1767 vnlru_proc_sleep();
1768 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
1769 return (true);
1770 }
1771
1772 static u_long uma_reclaim_calls;
1773 SYSCTL_ULONG(_vfs_vnode_vnlru, OID_AUTO, uma_reclaim_calls, CTLFLAG_RD | CTLFLAG_STATS,
1774 &uma_reclaim_calls, 0, "Number of calls to uma_reclaim");
1775
1776 static void
vnlru_proc(void)1777 vnlru_proc(void)
1778 {
1779 u_long rnumvnodes, rfreevnodes, target;
1780 unsigned long onumvnodes;
1781 int done, force, trigger, usevnodes;
1782 bool reclaim_nc_src, want_reread;
1783
1784 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1785 SHUTDOWN_PRI_FIRST);
1786
1787 force = 0;
1788 want_reread = false;
1789 for (;;) {
1790 kproc_suspend_check(vnlruproc);
1791
1792 if (force == 0 && vnlru_proc_light())
1793 continue;
1794
1795 mtx_lock(&vnode_list_mtx);
1796 rnumvnodes = atomic_load_long(&numvnodes);
1797
1798 if (want_reread) {
1799 force = vnlru_under(numvnodes, vhiwat) ? 1 : 0;
1800 want_reread = false;
1801 }
1802
1803 /*
1804 * If numvnodes is too large (due to desiredvnodes being
1805 * adjusted using its sysctl, or emergency growth), first
1806 * try to reduce it by discarding free vnodes.
1807 */
1808 if (rnumvnodes > desiredvnodes + 10) {
1809 vnlru_free_locked_vnlru(rnumvnodes - desiredvnodes);
1810 mtx_lock(&vnode_list_mtx);
1811 rnumvnodes = atomic_load_long(&numvnodes);
1812 }
1813 /*
1814 * Sleep if the vnode cache is in a good state. This is
1815 * when it is not over-full and has space for about a 4%
1816 * or 9% expansion (by growing its size or inexcessively
1817 * reducing free vnode count). Otherwise, try to reclaim
1818 * space for a 10% expansion.
1819 */
1820 if (vstir && force == 0) {
1821 force = 1;
1822 vstir = false;
1823 }
1824 if (force == 0 && !vnlru_under(rnumvnodes, vlowat)) {
1825 vnlru_proc_sleep();
1826 continue;
1827 }
1828 rfreevnodes = vnlru_read_freevnodes();
1829
1830 onumvnodes = rnumvnodes;
1831 /*
1832 * Calculate parameters for recycling. These are the same
1833 * throughout the loop to give some semblance of fairness.
1834 * The trigger point is to avoid recycling vnodes with lots
1835 * of resident pages. We aren't trying to free memory; we
1836 * are trying to recycle or at least free vnodes.
1837 */
1838 if (rnumvnodes <= desiredvnodes)
1839 usevnodes = rnumvnodes - rfreevnodes;
1840 else
1841 usevnodes = rnumvnodes;
1842 if (usevnodes <= 0)
1843 usevnodes = 1;
1844 /*
1845 * The trigger value is chosen to give a conservatively
1846 * large value to ensure that it alone doesn't prevent
1847 * making progress. The value can easily be so large that
1848 * it is effectively infinite in some congested and
1849 * misconfigured cases, and this is necessary. Normally
1850 * it is about 8 to 100 (pages), which is quite large.
1851 */
1852 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1853 if (force < 2)
1854 trigger = vsmalltrigger;
1855 reclaim_nc_src = force >= 3;
1856 target = rnumvnodes * (int64_t)gapvnodes / imax(desiredvnodes, 1);
1857 target = target / 10 + 1;
1858 done = vlrureclaim(reclaim_nc_src, trigger, target);
1859 mtx_unlock(&vnode_list_mtx);
1860 /*
1861 * Total number of vnodes can transiently go slightly above the
1862 * limit (see vn_alloc_hard), no need to call uma_reclaim if
1863 * this happens.
1864 */
1865 if (onumvnodes + VNLRU_COUNT_SLOP + 1000 > desiredvnodes &&
1866 numvnodes <= desiredvnodes) {
1867 uma_reclaim_calls++;
1868 uma_reclaim(UMA_RECLAIM_DRAIN);
1869 }
1870 if (done == 0) {
1871 if (force == 0 || force == 1) {
1872 force = 2;
1873 continue;
1874 }
1875 if (force == 2) {
1876 force = 3;
1877 continue;
1878 }
1879 want_reread = true;
1880 force = 0;
1881 vnlru_nowhere++;
1882 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1883 } else {
1884 want_reread = true;
1885 kern_yield(PRI_USER);
1886 }
1887 }
1888 }
1889
1890 static struct kproc_desc vnlru_kp = {
1891 "vnlru",
1892 vnlru_proc,
1893 &vnlruproc
1894 };
1895 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1896 &vnlru_kp);
1897
1898 /*
1899 * Routines having to do with the management of the vnode table.
1900 */
1901
1902 /*
1903 * Try to recycle a freed vnode.
1904 */
1905 static int
vtryrecycle(struct vnode * vp,bool isvnlru)1906 vtryrecycle(struct vnode *vp, bool isvnlru)
1907 {
1908 struct mount *vnmp;
1909
1910 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1911 VNPASS(vp->v_holdcnt > 0, vp);
1912 /*
1913 * This vnode may found and locked via some other list, if so we
1914 * can't recycle it yet.
1915 */
1916 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1917 CTR2(KTR_VFS,
1918 "%s: impossible to recycle, vp %p lock is already held",
1919 __func__, vp);
1920 vdrop_recycle(vp);
1921 return (EWOULDBLOCK);
1922 }
1923 /*
1924 * Don't recycle if its filesystem is being suspended.
1925 */
1926 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1927 VOP_UNLOCK(vp);
1928 CTR2(KTR_VFS,
1929 "%s: impossible to recycle, cannot start the write for %p",
1930 __func__, vp);
1931 vdrop_recycle(vp);
1932 return (EBUSY);
1933 }
1934 /*
1935 * If we got this far, we need to acquire the interlock and see if
1936 * anyone picked up this vnode from another list. If not, we will
1937 * mark it with DOOMED via vgonel() so that anyone who does find it
1938 * will skip over it.
1939 */
1940 VI_LOCK(vp);
1941 if (vp->v_usecount) {
1942 VOP_UNLOCK(vp);
1943 vdropl_recycle(vp);
1944 vn_finished_write(vnmp);
1945 CTR2(KTR_VFS,
1946 "%s: impossible to recycle, %p is already referenced",
1947 __func__, vp);
1948 return (EBUSY);
1949 }
1950 if (!VN_IS_DOOMED(vp)) {
1951 if (isvnlru)
1952 recycles_free_count++;
1953 else
1954 counter_u64_add(direct_recycles_free_count, 1);
1955 vgonel(vp);
1956 }
1957 VOP_UNLOCK(vp);
1958 vdropl_recycle(vp);
1959 vn_finished_write(vnmp);
1960 return (0);
1961 }
1962
1963 /*
1964 * Allocate a new vnode.
1965 *
1966 * The operation never returns an error. Returning an error was disabled
1967 * in r145385 (dated 2005) with the following comment:
1968 *
1969 * XXX Not all VFS_VGET/ffs_vget callers check returns.
1970 *
1971 * Given the age of this commit (almost 15 years at the time of writing this
1972 * comment) restoring the ability to fail requires a significant audit of
1973 * all codepaths.
1974 *
1975 * The routine can try to free a vnode or stall for up to 1 second waiting for
1976 * vnlru to clear things up, but ultimately always performs a M_WAITOK allocation.
1977 */
1978 static u_long vn_alloc_cyclecount;
1979 static u_long vn_alloc_sleeps;
1980
1981 SYSCTL_ULONG(_vfs_vnode_stats, OID_AUTO, alloc_sleeps, CTLFLAG_RD, &vn_alloc_sleeps, 0,
1982 "Number of times vnode allocation blocked waiting on vnlru");
1983
1984 static struct vnode * __noinline
vn_alloc_hard(struct mount * mp,u_long rnumvnodes,bool bumped)1985 vn_alloc_hard(struct mount *mp, u_long rnumvnodes, bool bumped)
1986 {
1987 u_long rfreevnodes;
1988
1989 if (bumped) {
1990 if (rnumvnodes > desiredvnodes + VNLRU_COUNT_SLOP) {
1991 atomic_subtract_long(&numvnodes, 1);
1992 bumped = false;
1993 }
1994 }
1995
1996 mtx_lock(&vnode_list_mtx);
1997
1998 rfreevnodes = vnlru_read_freevnodes();
1999 if (vn_alloc_cyclecount++ >= rfreevnodes) {
2000 vn_alloc_cyclecount = 0;
2001 vstir = true;
2002 }
2003 /*
2004 * Grow the vnode cache if it will not be above its target max after
2005 * growing. Otherwise, if there is at least one free vnode, try to
2006 * reclaim 1 item from it before growing the cache (possibly above its
2007 * target max if the reclamation failed or is delayed).
2008 */
2009 if (vnlru_free_locked_direct(1) > 0)
2010 goto alloc;
2011 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
2012 if (mp == NULL || (mp->mnt_kern_flag & MNTK_SUSPEND) == 0) {
2013 /*
2014 * Wait for space for a new vnode.
2015 */
2016 if (bumped) {
2017 atomic_subtract_long(&numvnodes, 1);
2018 bumped = false;
2019 }
2020 mtx_lock(&vnode_list_mtx);
2021 vnlru_kick_locked();
2022 vn_alloc_sleeps++;
2023 msleep(&vnlruproc_sig, &vnode_list_mtx, PVFS, "vlruwk", hz);
2024 if (atomic_load_long(&numvnodes) + 1 > desiredvnodes &&
2025 vnlru_read_freevnodes() > 1)
2026 vnlru_free_locked_direct(1);
2027 else
2028 mtx_unlock(&vnode_list_mtx);
2029 }
2030 alloc:
2031 mtx_assert(&vnode_list_mtx, MA_NOTOWNED);
2032 if (!bumped)
2033 atomic_add_long(&numvnodes, 1);
2034 vnlru_kick_cond();
2035 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2036 }
2037
2038 static struct vnode *
vn_alloc(struct mount * mp)2039 vn_alloc(struct mount *mp)
2040 {
2041 u_long rnumvnodes;
2042
2043 if (__predict_false(vn_alloc_cyclecount != 0))
2044 return (vn_alloc_hard(mp, 0, false));
2045 rnumvnodes = atomic_fetchadd_long(&numvnodes, 1) + 1;
2046 if (__predict_false(vnlru_under(rnumvnodes, vlowat))) {
2047 return (vn_alloc_hard(mp, rnumvnodes, true));
2048 }
2049
2050 return (uma_zalloc_smr(vnode_zone, M_WAITOK));
2051 }
2052
2053 static void
vn_free(struct vnode * vp)2054 vn_free(struct vnode *vp)
2055 {
2056
2057 atomic_subtract_long(&numvnodes, 1);
2058 uma_zfree_smr(vnode_zone, vp);
2059 }
2060
2061 /*
2062 * Allocate a new vnode.
2063 */
2064 int
getnewvnode(const char * tag,struct mount * mp,struct vop_vector * vops,struct vnode ** vpp)2065 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
2066 struct vnode **vpp)
2067 {
2068 struct vnode *vp;
2069 struct thread *td;
2070 struct lock_object *lo;
2071
2072 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
2073
2074 KASSERT(vops->registered,
2075 ("%s: not registered vector op %p\n", __func__, vops));
2076 cache_validate_vop_vector(mp, vops);
2077
2078 td = curthread;
2079 if (td->td_vp_reserved != NULL) {
2080 vp = td->td_vp_reserved;
2081 td->td_vp_reserved = NULL;
2082 } else {
2083 vp = vn_alloc(mp);
2084 }
2085 counter_u64_add(vnodes_created, 1);
2086
2087 vn_set_state(vp, VSTATE_UNINITIALIZED);
2088
2089 /*
2090 * Locks are given the generic name "vnode" when created.
2091 * Follow the historic practice of using the filesystem
2092 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
2093 *
2094 * Locks live in a witness group keyed on their name. Thus,
2095 * when a lock is renamed, it must also move from the witness
2096 * group of its old name to the witness group of its new name.
2097 *
2098 * The change only needs to be made when the vnode moves
2099 * from one filesystem type to another. We ensure that each
2100 * filesystem use a single static name pointer for its tag so
2101 * that we can compare pointers rather than doing a strcmp().
2102 */
2103 lo = &vp->v_vnlock->lock_object;
2104 #ifdef WITNESS
2105 if (lo->lo_name != tag) {
2106 #endif
2107 lo->lo_name = tag;
2108 #ifdef WITNESS
2109 WITNESS_DESTROY(lo);
2110 WITNESS_INIT(lo, tag);
2111 }
2112 #endif
2113 /*
2114 * By default, don't allow shared locks unless filesystems opt-in.
2115 */
2116 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
2117 /*
2118 * Finalize various vnode identity bits.
2119 */
2120 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
2121 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
2122 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
2123 vp->v_type = VNON;
2124 vp->v_op = vops;
2125 vp->v_irflag = 0;
2126 v_init_counters(vp);
2127 vn_seqc_init(vp);
2128 vp->v_bufobj.bo_ops = &buf_ops_bio;
2129 #ifdef DIAGNOSTIC
2130 if (mp == NULL && vops != &dead_vnodeops)
2131 printf("NULL mp in getnewvnode(9), tag %s\n", tag);
2132 #endif
2133 #ifdef MAC
2134 mac_vnode_init(vp);
2135 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
2136 mac_vnode_associate_singlelabel(mp, vp);
2137 #endif
2138 if (mp != NULL) {
2139 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
2140 }
2141
2142 /*
2143 * For the filesystems which do not use vfs_hash_insert(),
2144 * still initialize v_hash to have vfs_hash_index() useful.
2145 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
2146 * its own hashing.
2147 */
2148 vp->v_hash = (uintptr_t)vp >> vnsz2log;
2149
2150 *vpp = vp;
2151 return (0);
2152 }
2153
2154 void
getnewvnode_reserve(void)2155 getnewvnode_reserve(void)
2156 {
2157 struct thread *td;
2158
2159 td = curthread;
2160 MPASS(td->td_vp_reserved == NULL);
2161 td->td_vp_reserved = vn_alloc(NULL);
2162 }
2163
2164 void
getnewvnode_drop_reserve(void)2165 getnewvnode_drop_reserve(void)
2166 {
2167 struct thread *td;
2168
2169 td = curthread;
2170 if (td->td_vp_reserved != NULL) {
2171 vn_free(td->td_vp_reserved);
2172 td->td_vp_reserved = NULL;
2173 }
2174 }
2175
2176 static void __noinline
freevnode(struct vnode * vp)2177 freevnode(struct vnode *vp)
2178 {
2179 struct bufobj *bo;
2180
2181 /*
2182 * The vnode has been marked for destruction, so free it.
2183 *
2184 * The vnode will be returned to the zone where it will
2185 * normally remain until it is needed for another vnode. We
2186 * need to cleanup (or verify that the cleanup has already
2187 * been done) any residual data left from its current use
2188 * so as not to contaminate the freshly allocated vnode.
2189 */
2190 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2191 /*
2192 * Paired with vgone.
2193 */
2194 vn_seqc_write_end_free(vp);
2195
2196 bo = &vp->v_bufobj;
2197 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2198 VNPASS(vp->v_holdcnt == VHOLD_NO_SMR, vp);
2199 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2200 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2201 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2202 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2203 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2204 ("clean blk trie not empty"));
2205 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2206 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2207 ("dirty blk trie not empty"));
2208 VNASSERT((vp->v_iflag & (VI_DOINGINACT | VI_OWEINACT)) == 0, vp,
2209 ("Leaked inactivation"));
2210 VI_UNLOCK(vp);
2211 cache_assert_no_entries(vp);
2212
2213 #ifdef MAC
2214 mac_vnode_destroy(vp);
2215 #endif
2216 if (vp->v_pollinfo != NULL) {
2217 /*
2218 * Use LK_NOWAIT to shut up witness about the lock. We may get
2219 * here while having another vnode locked when trying to
2220 * satisfy a lookup and needing to recycle.
2221 */
2222 VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT);
2223 destroy_vpollinfo(vp->v_pollinfo);
2224 VOP_UNLOCK(vp);
2225 vp->v_pollinfo = NULL;
2226 }
2227 vp->v_mountedhere = NULL;
2228 vp->v_unpcb = NULL;
2229 vp->v_rdev = NULL;
2230 vp->v_fifoinfo = NULL;
2231 vp->v_iflag = 0;
2232 vp->v_vflag = 0;
2233 bo->bo_flag = 0;
2234 vn_free(vp);
2235 }
2236
2237 /*
2238 * Delete from old mount point vnode list, if on one.
2239 */
2240 static void
delmntque(struct vnode * vp)2241 delmntque(struct vnode *vp)
2242 {
2243 struct mount *mp;
2244
2245 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
2246
2247 mp = vp->v_mount;
2248 MNT_ILOCK(mp);
2249 VI_LOCK(vp);
2250 vp->v_mount = NULL;
2251 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
2252 ("bad mount point vnode list size"));
2253 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2254 mp->mnt_nvnodelistsize--;
2255 MNT_REL(mp);
2256 MNT_IUNLOCK(mp);
2257 /*
2258 * The caller expects the interlock to be still held.
2259 */
2260 ASSERT_VI_LOCKED(vp, __func__);
2261 }
2262
2263 static int
insmntque1_int(struct vnode * vp,struct mount * mp,bool dtr)2264 insmntque1_int(struct vnode *vp, struct mount *mp, bool dtr)
2265 {
2266
2267 KASSERT(vp->v_mount == NULL,
2268 ("insmntque: vnode already on per mount vnode list"));
2269 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
2270 if ((mp->mnt_kern_flag & MNTK_UNLOCKED_INSMNTQUE) == 0) {
2271 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
2272 } else {
2273 KASSERT(!dtr,
2274 ("%s: can't have MNTK_UNLOCKED_INSMNTQUE and cleanup",
2275 __func__));
2276 }
2277
2278 /*
2279 * We acquire the vnode interlock early to ensure that the
2280 * vnode cannot be recycled by another process releasing a
2281 * holdcnt on it before we get it on both the vnode list
2282 * and the active vnode list. The mount mutex protects only
2283 * manipulation of the vnode list and the vnode freelist
2284 * mutex protects only manipulation of the active vnode list.
2285 * Hence the need to hold the vnode interlock throughout.
2286 */
2287 MNT_ILOCK(mp);
2288 VI_LOCK(vp);
2289 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
2290 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
2291 mp->mnt_nvnodelistsize == 0)) &&
2292 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
2293 VI_UNLOCK(vp);
2294 MNT_IUNLOCK(mp);
2295 if (dtr) {
2296 vp->v_data = NULL;
2297 vp->v_op = &dead_vnodeops;
2298 vgone(vp);
2299 vput(vp);
2300 }
2301 return (EBUSY);
2302 }
2303 vp->v_mount = mp;
2304 MNT_REF(mp);
2305 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
2306 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
2307 ("neg mount point vnode list size"));
2308 mp->mnt_nvnodelistsize++;
2309 VI_UNLOCK(vp);
2310 MNT_IUNLOCK(mp);
2311 return (0);
2312 }
2313
2314 /*
2315 * Insert into list of vnodes for the new mount point, if available.
2316 * insmntque() reclaims the vnode on insertion failure, insmntque1()
2317 * leaves handling of the vnode to the caller.
2318 */
2319 int
insmntque(struct vnode * vp,struct mount * mp)2320 insmntque(struct vnode *vp, struct mount *mp)
2321 {
2322 return (insmntque1_int(vp, mp, true));
2323 }
2324
2325 int
insmntque1(struct vnode * vp,struct mount * mp)2326 insmntque1(struct vnode *vp, struct mount *mp)
2327 {
2328 return (insmntque1_int(vp, mp, false));
2329 }
2330
2331 /*
2332 * Flush out and invalidate all buffers associated with a bufobj
2333 * Called with the underlying object locked.
2334 */
2335 int
bufobj_invalbuf(struct bufobj * bo,int flags,int slpflag,int slptimeo)2336 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
2337 {
2338 int error;
2339
2340 BO_LOCK(bo);
2341 if (flags & V_SAVE) {
2342 error = bufobj_wwait(bo, slpflag, slptimeo);
2343 if (error) {
2344 BO_UNLOCK(bo);
2345 return (error);
2346 }
2347 if (bo->bo_dirty.bv_cnt > 0) {
2348 BO_UNLOCK(bo);
2349 do {
2350 error = BO_SYNC(bo, MNT_WAIT);
2351 } while (error == ERELOOKUP);
2352 if (error != 0)
2353 return (error);
2354 BO_LOCK(bo);
2355 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) {
2356 BO_UNLOCK(bo);
2357 return (EBUSY);
2358 }
2359 }
2360 }
2361 /*
2362 * If you alter this loop please notice that interlock is dropped and
2363 * reacquired in flushbuflist. Special care is needed to ensure that
2364 * no race conditions occur from this.
2365 */
2366 do {
2367 error = flushbuflist(&bo->bo_clean,
2368 flags, bo, slpflag, slptimeo);
2369 if (error == 0 && !(flags & V_CLEANONLY))
2370 error = flushbuflist(&bo->bo_dirty,
2371 flags, bo, slpflag, slptimeo);
2372 if (error != 0 && error != EAGAIN) {
2373 BO_UNLOCK(bo);
2374 return (error);
2375 }
2376 } while (error != 0);
2377
2378 /*
2379 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
2380 * have write I/O in-progress but if there is a VM object then the
2381 * VM object can also have read-I/O in-progress.
2382 */
2383 do {
2384 bufobj_wwait(bo, 0, 0);
2385 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) {
2386 BO_UNLOCK(bo);
2387 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx");
2388 BO_LOCK(bo);
2389 }
2390 } while (bo->bo_numoutput > 0);
2391 BO_UNLOCK(bo);
2392
2393 /*
2394 * Destroy the copy in the VM cache, too.
2395 */
2396 if (bo->bo_object != NULL &&
2397 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
2398 VM_OBJECT_WLOCK(bo->bo_object);
2399 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
2400 OBJPR_CLEANONLY : 0);
2401 VM_OBJECT_WUNLOCK(bo->bo_object);
2402 }
2403
2404 #ifdef INVARIANTS
2405 BO_LOCK(bo);
2406 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO |
2407 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 ||
2408 bo->bo_clean.bv_cnt > 0))
2409 panic("vinvalbuf: flush failed");
2410 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
2411 bo->bo_dirty.bv_cnt > 0)
2412 panic("vinvalbuf: flush dirty failed");
2413 BO_UNLOCK(bo);
2414 #endif
2415 return (0);
2416 }
2417
2418 /*
2419 * Flush out and invalidate all buffers associated with a vnode.
2420 * Called with the underlying object locked.
2421 */
2422 int
vinvalbuf(struct vnode * vp,int flags,int slpflag,int slptimeo)2423 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
2424 {
2425
2426 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2427 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
2428 if (vp->v_object != NULL && vp->v_object->handle != vp)
2429 return (0);
2430 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
2431 }
2432
2433 /*
2434 * Flush out buffers on the specified list.
2435 *
2436 */
2437 static int
flushbuflist(struct bufv * bufv,int flags,struct bufobj * bo,int slpflag,int slptimeo)2438 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
2439 int slptimeo)
2440 {
2441 struct buf *bp, *nbp;
2442 int retval, error;
2443 daddr_t lblkno;
2444 b_xflags_t xflags;
2445
2446 ASSERT_BO_WLOCKED(bo);
2447
2448 retval = 0;
2449 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
2450 /*
2451 * If we are flushing both V_NORMAL and V_ALT buffers then
2452 * do not skip any buffers. If we are flushing only V_NORMAL
2453 * buffers then skip buffers marked as BX_ALTDATA. If we are
2454 * flushing only V_ALT buffers then skip buffers not marked
2455 * as BX_ALTDATA.
2456 */
2457 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) &&
2458 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) ||
2459 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) {
2460 continue;
2461 }
2462 if (nbp != NULL) {
2463 lblkno = nbp->b_lblkno;
2464 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
2465 }
2466 retval = EAGAIN;
2467 error = BUF_TIMELOCK(bp,
2468 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
2469 "flushbuf", slpflag, slptimeo);
2470 if (error) {
2471 BO_LOCK(bo);
2472 return (error != ENOLCK ? error : EAGAIN);
2473 }
2474 KASSERT(bp->b_bufobj == bo,
2475 ("bp %p wrong b_bufobj %p should be %p",
2476 bp, bp->b_bufobj, bo));
2477 /*
2478 * XXX Since there are no node locks for NFS, I
2479 * believe there is a slight chance that a delayed
2480 * write will occur while sleeping just above, so
2481 * check for it.
2482 */
2483 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
2484 (flags & V_SAVE)) {
2485 bremfree(bp);
2486 bp->b_flags |= B_ASYNC;
2487 bwrite(bp);
2488 BO_LOCK(bo);
2489 return (EAGAIN); /* XXX: why not loop ? */
2490 }
2491 bremfree(bp);
2492 bp->b_flags |= (B_INVAL | B_RELBUF);
2493 bp->b_flags &= ~B_ASYNC;
2494 brelse(bp);
2495 BO_LOCK(bo);
2496 if (nbp == NULL)
2497 break;
2498 nbp = gbincore(bo, lblkno);
2499 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2500 != xflags)
2501 break; /* nbp invalid */
2502 }
2503 return (retval);
2504 }
2505
2506 int
bnoreuselist(struct bufv * bufv,struct bufobj * bo,daddr_t startn,daddr_t endn)2507 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
2508 {
2509 struct buf *bp;
2510 int error;
2511 daddr_t lblkno;
2512
2513 ASSERT_BO_LOCKED(bo);
2514
2515 for (lblkno = startn;;) {
2516 again:
2517 bp = buf_lookup_ge(bufv, lblkno);
2518 if (bp == NULL || bp->b_lblkno >= endn)
2519 break;
2520 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
2521 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
2522 if (error != 0) {
2523 BO_RLOCK(bo);
2524 if (error == ENOLCK)
2525 goto again;
2526 return (error);
2527 }
2528 KASSERT(bp->b_bufobj == bo,
2529 ("bp %p wrong b_bufobj %p should be %p",
2530 bp, bp->b_bufobj, bo));
2531 lblkno = bp->b_lblkno + 1;
2532 if ((bp->b_flags & B_MANAGED) == 0)
2533 bremfree(bp);
2534 bp->b_flags |= B_RELBUF;
2535 /*
2536 * In the VMIO case, use the B_NOREUSE flag to hint that the
2537 * pages backing each buffer in the range are unlikely to be
2538 * reused. Dirty buffers will have the hint applied once
2539 * they've been written.
2540 */
2541 if ((bp->b_flags & B_VMIO) != 0)
2542 bp->b_flags |= B_NOREUSE;
2543 brelse(bp);
2544 BO_RLOCK(bo);
2545 }
2546 return (0);
2547 }
2548
2549 /*
2550 * Truncate a file's buffer and pages to a specified length. This
2551 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
2552 * sync activity.
2553 */
2554 int
vtruncbuf(struct vnode * vp,off_t length,int blksize)2555 vtruncbuf(struct vnode *vp, off_t length, int blksize)
2556 {
2557 struct buf *bp, *nbp;
2558 struct bufobj *bo;
2559 daddr_t startlbn;
2560
2561 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__,
2562 vp, blksize, (uintmax_t)length);
2563
2564 /*
2565 * Round up to the *next* lbn.
2566 */
2567 startlbn = howmany(length, blksize);
2568
2569 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
2570
2571 bo = &vp->v_bufobj;
2572 restart_unlocked:
2573 BO_LOCK(bo);
2574
2575 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN)
2576 ;
2577
2578 if (length > 0) {
2579 /*
2580 * Write out vnode metadata, e.g. indirect blocks.
2581 */
2582 restartsync:
2583 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2584 if (bp->b_lblkno >= 0)
2585 continue;
2586 /*
2587 * Since we hold the vnode lock this should only
2588 * fail if we're racing with the buf daemon.
2589 */
2590 if (BUF_LOCK(bp,
2591 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2592 BO_LOCKPTR(bo)) == ENOLCK)
2593 goto restart_unlocked;
2594
2595 VNASSERT((bp->b_flags & B_DELWRI), vp,
2596 ("buf(%p) on dirty queue without DELWRI", bp));
2597
2598 bremfree(bp);
2599 bawrite(bp);
2600 BO_LOCK(bo);
2601 goto restartsync;
2602 }
2603 }
2604
2605 bufobj_wwait(bo, 0, 0);
2606 BO_UNLOCK(bo);
2607 vnode_pager_setsize(vp, length);
2608
2609 return (0);
2610 }
2611
2612 /*
2613 * Invalidate the cached pages of a file's buffer within the range of block
2614 * numbers [startlbn, endlbn).
2615 */
2616 void
v_inval_buf_range(struct vnode * vp,daddr_t startlbn,daddr_t endlbn,int blksize)2617 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn,
2618 int blksize)
2619 {
2620 struct bufobj *bo;
2621 off_t start, end;
2622
2623 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range");
2624
2625 start = blksize * startlbn;
2626 end = blksize * endlbn;
2627
2628 bo = &vp->v_bufobj;
2629 BO_LOCK(bo);
2630 MPASS(blksize == bo->bo_bsize);
2631
2632 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN)
2633 ;
2634
2635 BO_UNLOCK(bo);
2636 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1));
2637 }
2638
2639 static int
v_inval_buf_range_locked(struct vnode * vp,struct bufobj * bo,daddr_t startlbn,daddr_t endlbn)2640 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
2641 daddr_t startlbn, daddr_t endlbn)
2642 {
2643 struct bufv *bv;
2644 struct buf *bp, *nbp;
2645 uint8_t anyfreed;
2646 bool clean;
2647
2648 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked");
2649 ASSERT_BO_LOCKED(bo);
2650
2651 anyfreed = 1;
2652 clean = true;
2653 do {
2654 bv = clean ? &bo->bo_clean : &bo->bo_dirty;
2655 bp = buf_lookup_ge(bv, startlbn);
2656 if (bp == NULL)
2657 continue;
2658 TAILQ_FOREACH_FROM_SAFE(bp, &bv->bv_hd, b_bobufs, nbp) {
2659 if (bp->b_lblkno >= endlbn)
2660 break;
2661 if (BUF_LOCK(bp,
2662 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2663 BO_LOCKPTR(bo)) == ENOLCK) {
2664 BO_LOCK(bo);
2665 return (EAGAIN);
2666 }
2667
2668 bremfree(bp);
2669 bp->b_flags |= B_INVAL | B_RELBUF;
2670 bp->b_flags &= ~B_ASYNC;
2671 brelse(bp);
2672 anyfreed = 2;
2673
2674 BO_LOCK(bo);
2675 if (nbp != NULL &&
2676 (((nbp->b_xflags &
2677 (clean ? BX_VNCLEAN : BX_VNDIRTY)) == 0) ||
2678 nbp->b_vp != vp ||
2679 (nbp->b_flags & B_DELWRI) == (clean? B_DELWRI: 0)))
2680 return (EAGAIN);
2681 }
2682 } while (clean = !clean, anyfreed-- > 0);
2683 return (0);
2684 }
2685
2686 static void
buf_vlist_remove(struct buf * bp)2687 buf_vlist_remove(struct buf *bp)
2688 {
2689 struct bufv *bv;
2690 b_xflags_t flags;
2691
2692 flags = bp->b_xflags;
2693
2694 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
2695 ASSERT_BO_WLOCKED(bp->b_bufobj);
2696 KASSERT((flags & (BX_VNDIRTY | BX_VNCLEAN)) != 0 &&
2697 (flags & (BX_VNDIRTY | BX_VNCLEAN)) != (BX_VNDIRTY | BX_VNCLEAN),
2698 ("%s: buffer %p has invalid queue state", __func__, bp));
2699
2700 if ((flags & BX_VNDIRTY) != 0)
2701 bv = &bp->b_bufobj->bo_dirty;
2702 else
2703 bv = &bp->b_bufobj->bo_clean;
2704 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
2705 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
2706 bv->bv_cnt--;
2707 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
2708 }
2709
2710 /*
2711 * Add the buffer to the sorted clean or dirty block list. Return zero on
2712 * success, EEXIST if a buffer with this identity already exists, or another
2713 * error on allocation failure.
2714 */
2715 static inline int
buf_vlist_find_or_add(struct buf * bp,struct bufobj * bo,b_xflags_t xflags)2716 buf_vlist_find_or_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2717 {
2718 struct bufv *bv;
2719 struct buf *n;
2720 int error;
2721
2722 ASSERT_BO_WLOCKED(bo);
2723 KASSERT((bo->bo_flag & BO_NOBUFS) == 0,
2724 ("buf_vlist_add: bo %p does not allow bufs", bo));
2725 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
2726 ("dead bo %p", bo));
2727 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == xflags,
2728 ("buf_vlist_add: b_xflags %#x not set on bp %p", xflags, bp));
2729
2730 if (xflags & BX_VNDIRTY)
2731 bv = &bo->bo_dirty;
2732 else
2733 bv = &bo->bo_clean;
2734
2735 error = buf_insert_lookup_le(bv, bp, &n);
2736 if (n == NULL) {
2737 KASSERT(error != EEXIST,
2738 ("buf_vlist_add: EEXIST but no existing buf found: bp %p",
2739 bp));
2740 } else {
2741 KASSERT(n->b_lblkno <= bp->b_lblkno,
2742 ("buf_vlist_add: out of order insert/lookup: bp %p n %p",
2743 bp, n));
2744 KASSERT((n->b_lblkno == bp->b_lblkno) == (error == EEXIST),
2745 ("buf_vlist_add: inconsistent result for existing buf: "
2746 "error %d bp %p n %p", error, bp, n));
2747 }
2748 if (error != 0)
2749 return (error);
2750
2751 /* Keep the list ordered. */
2752 if (n == NULL) {
2753 KASSERT(TAILQ_EMPTY(&bv->bv_hd) ||
2754 bp->b_lblkno < TAILQ_FIRST(&bv->bv_hd)->b_lblkno,
2755 ("buf_vlist_add: queue order: "
2756 "%p should be before first %p",
2757 bp, TAILQ_FIRST(&bv->bv_hd)));
2758 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
2759 } else {
2760 KASSERT(TAILQ_NEXT(n, b_bobufs) == NULL ||
2761 bp->b_lblkno < TAILQ_NEXT(n, b_bobufs)->b_lblkno,
2762 ("buf_vlist_add: queue order: "
2763 "%p should be before next %p",
2764 bp, TAILQ_NEXT(n, b_bobufs)));
2765 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
2766 }
2767
2768 bv->bv_cnt++;
2769 return (0);
2770 }
2771
2772 /*
2773 * Add the buffer to the sorted clean or dirty block list.
2774 *
2775 * NOTE: xflags is passed as a constant, optimizing this inline function!
2776 */
2777 static void
buf_vlist_add(struct buf * bp,struct bufobj * bo,b_xflags_t xflags)2778 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2779 {
2780 int error;
2781
2782 KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
2783 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
2784 bp->b_xflags |= xflags;
2785 error = buf_vlist_find_or_add(bp, bo, xflags);
2786 if (error)
2787 panic("buf_vlist_add: error=%d", error);
2788 }
2789
2790 /*
2791 * Look up a buffer using the buffer tries.
2792 */
2793 struct buf *
gbincore(struct bufobj * bo,daddr_t lblkno)2794 gbincore(struct bufobj *bo, daddr_t lblkno)
2795 {
2796 struct buf *bp;
2797
2798 ASSERT_BO_LOCKED(bo);
2799 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
2800 if (bp != NULL)
2801 return (bp);
2802 return (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno));
2803 }
2804
2805 /*
2806 * Look up a buf using the buffer tries, without the bufobj lock. This relies
2807 * on SMR for safe lookup, and bufs being in a no-free zone to provide type
2808 * stability of the result. Like other lockless lookups, the found buf may
2809 * already be invalid by the time this function returns.
2810 */
2811 struct buf *
gbincore_unlocked(struct bufobj * bo,daddr_t lblkno)2812 gbincore_unlocked(struct bufobj *bo, daddr_t lblkno)
2813 {
2814 struct buf *bp;
2815
2816 ASSERT_BO_UNLOCKED(bo);
2817 bp = BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_clean.bv_root, lblkno);
2818 if (bp != NULL)
2819 return (bp);
2820 return (BUF_PCTRIE_LOOKUP_UNLOCKED(&bo->bo_dirty.bv_root, lblkno));
2821 }
2822
2823 /*
2824 * Associate a buffer with a vnode.
2825 */
2826 int
bgetvp(struct vnode * vp,struct buf * bp)2827 bgetvp(struct vnode *vp, struct buf *bp)
2828 {
2829 struct bufobj *bo;
2830 int error;
2831
2832 bo = &vp->v_bufobj;
2833 ASSERT_BO_UNLOCKED(bo);
2834 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
2835
2836 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
2837 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
2838 ("bgetvp: bp already attached! %p", bp));
2839
2840 /*
2841 * Add the buf to the vnode's clean list unless we lost a race and find
2842 * an existing buf in either dirty or clean.
2843 */
2844 bp->b_vp = vp;
2845 bp->b_bufobj = bo;
2846 bp->b_xflags |= BX_VNCLEAN;
2847 error = EEXIST;
2848 BO_LOCK(bo);
2849 if (BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, bp->b_lblkno) == NULL)
2850 error = buf_vlist_find_or_add(bp, bo, BX_VNCLEAN);
2851 BO_UNLOCK(bo);
2852 if (__predict_true(error == 0)) {
2853 vhold(vp);
2854 return (0);
2855 }
2856 if (error != EEXIST)
2857 panic("bgetvp: buf_vlist_add error: %d", error);
2858 bp->b_vp = NULL;
2859 bp->b_bufobj = NULL;
2860 bp->b_xflags &= ~BX_VNCLEAN;
2861 return (error);
2862 }
2863
2864 /*
2865 * Disassociate a buffer from a vnode.
2866 */
2867 void
brelvp(struct buf * bp)2868 brelvp(struct buf *bp)
2869 {
2870 struct bufobj *bo;
2871 struct vnode *vp;
2872
2873 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
2874 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
2875
2876 /*
2877 * Delete from old vnode list, if on one.
2878 */
2879 vp = bp->b_vp; /* XXX */
2880 bo = bp->b_bufobj;
2881 BO_LOCK(bo);
2882 buf_vlist_remove(bp);
2883 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2884 bo->bo_flag &= ~BO_ONWORKLST;
2885 mtx_lock(&sync_mtx);
2886 LIST_REMOVE(bo, bo_synclist);
2887 syncer_worklist_len--;
2888 mtx_unlock(&sync_mtx);
2889 }
2890 bp->b_vp = NULL;
2891 bp->b_bufobj = NULL;
2892 BO_UNLOCK(bo);
2893 vdrop(vp);
2894 }
2895
2896 /*
2897 * Add an item to the syncer work queue.
2898 */
2899 static void
vn_syncer_add_to_worklist(struct bufobj * bo,int delay)2900 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2901 {
2902 int slot;
2903
2904 ASSERT_BO_WLOCKED(bo);
2905
2906 mtx_lock(&sync_mtx);
2907 if (bo->bo_flag & BO_ONWORKLST)
2908 LIST_REMOVE(bo, bo_synclist);
2909 else {
2910 bo->bo_flag |= BO_ONWORKLST;
2911 syncer_worklist_len++;
2912 }
2913
2914 if (delay > syncer_maxdelay - 2)
2915 delay = syncer_maxdelay - 2;
2916 slot = (syncer_delayno + delay) & syncer_mask;
2917
2918 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2919 mtx_unlock(&sync_mtx);
2920 }
2921
2922 static int
sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)2923 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2924 {
2925 int error, len;
2926
2927 mtx_lock(&sync_mtx);
2928 len = syncer_worklist_len - sync_vnode_count;
2929 mtx_unlock(&sync_mtx);
2930 error = SYSCTL_OUT(req, &len, sizeof(len));
2931 return (error);
2932 }
2933
2934 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len,
2935 CTLTYPE_INT | CTLFLAG_MPSAFE| CTLFLAG_RD, NULL, 0,
2936 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2937
2938 static struct proc *updateproc;
2939 static void sched_sync(void);
2940 static struct kproc_desc up_kp = {
2941 "syncer",
2942 sched_sync,
2943 &updateproc
2944 };
2945 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2946
2947 static int
sync_vnode(struct synclist * slp,struct bufobj ** bo,struct thread * td)2948 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2949 {
2950 struct vnode *vp;
2951 struct mount *mp;
2952
2953 *bo = LIST_FIRST(slp);
2954 if (*bo == NULL)
2955 return (0);
2956 vp = bo2vnode(*bo);
2957 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2958 return (1);
2959 /*
2960 * We use vhold in case the vnode does not
2961 * successfully sync. vhold prevents the vnode from
2962 * going away when we unlock the sync_mtx so that
2963 * we can acquire the vnode interlock.
2964 */
2965 vholdl(vp);
2966 mtx_unlock(&sync_mtx);
2967 VI_UNLOCK(vp);
2968 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2969 vdrop(vp);
2970 mtx_lock(&sync_mtx);
2971 return (*bo == LIST_FIRST(slp));
2972 }
2973 MPASSERT(mp == NULL || (curthread->td_pflags & TDP_IGNSUSP) != 0 ||
2974 (mp->mnt_kern_flag & MNTK_SUSPENDED) == 0, mp,
2975 ("suspended mp syncing vp %p", vp));
2976 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2977 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2978 VOP_UNLOCK(vp);
2979 vn_finished_write(mp);
2980 BO_LOCK(*bo);
2981 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2982 /*
2983 * Put us back on the worklist. The worklist
2984 * routine will remove us from our current
2985 * position and then add us back in at a later
2986 * position.
2987 */
2988 vn_syncer_add_to_worklist(*bo, syncdelay);
2989 }
2990 BO_UNLOCK(*bo);
2991 vdrop(vp);
2992 mtx_lock(&sync_mtx);
2993 return (0);
2994 }
2995
2996 static int first_printf = 1;
2997
2998 /*
2999 * System filesystem synchronizer daemon.
3000 */
3001 static void
sched_sync(void)3002 sched_sync(void)
3003 {
3004 struct synclist *next, *slp;
3005 struct bufobj *bo;
3006 long starttime;
3007 struct thread *td = curthread;
3008 int last_work_seen;
3009 int net_worklist_len;
3010 int syncer_final_iter;
3011 int error;
3012
3013 last_work_seen = 0;
3014 syncer_final_iter = 0;
3015 syncer_state = SYNCER_RUNNING;
3016 starttime = time_uptime;
3017 td->td_pflags |= TDP_NORUNNINGBUF;
3018
3019 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
3020 SHUTDOWN_PRI_LAST);
3021
3022 mtx_lock(&sync_mtx);
3023 for (;;) {
3024 if (syncer_state == SYNCER_FINAL_DELAY &&
3025 syncer_final_iter == 0) {
3026 mtx_unlock(&sync_mtx);
3027 kproc_suspend_check(td->td_proc);
3028 mtx_lock(&sync_mtx);
3029 }
3030 net_worklist_len = syncer_worklist_len - sync_vnode_count;
3031 if (syncer_state != SYNCER_RUNNING &&
3032 starttime != time_uptime) {
3033 if (first_printf) {
3034 printf("\nSyncing disks, vnodes remaining... ");
3035 first_printf = 0;
3036 }
3037 printf("%d ", net_worklist_len);
3038 }
3039 starttime = time_uptime;
3040
3041 /*
3042 * Push files whose dirty time has expired. Be careful
3043 * of interrupt race on slp queue.
3044 *
3045 * Skip over empty worklist slots when shutting down.
3046 */
3047 do {
3048 slp = &syncer_workitem_pending[syncer_delayno];
3049 syncer_delayno += 1;
3050 if (syncer_delayno == syncer_maxdelay)
3051 syncer_delayno = 0;
3052 next = &syncer_workitem_pending[syncer_delayno];
3053 /*
3054 * If the worklist has wrapped since the
3055 * it was emptied of all but syncer vnodes,
3056 * switch to the FINAL_DELAY state and run
3057 * for one more second.
3058 */
3059 if (syncer_state == SYNCER_SHUTTING_DOWN &&
3060 net_worklist_len == 0 &&
3061 last_work_seen == syncer_delayno) {
3062 syncer_state = SYNCER_FINAL_DELAY;
3063 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
3064 }
3065 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
3066 syncer_worklist_len > 0);
3067
3068 /*
3069 * Keep track of the last time there was anything
3070 * on the worklist other than syncer vnodes.
3071 * Return to the SHUTTING_DOWN state if any
3072 * new work appears.
3073 */
3074 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
3075 last_work_seen = syncer_delayno;
3076 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
3077 syncer_state = SYNCER_SHUTTING_DOWN;
3078 while (!LIST_EMPTY(slp)) {
3079 error = sync_vnode(slp, &bo, td);
3080 if (error == 1) {
3081 LIST_REMOVE(bo, bo_synclist);
3082 LIST_INSERT_HEAD(next, bo, bo_synclist);
3083 continue;
3084 }
3085
3086 if (first_printf == 0) {
3087 /*
3088 * Drop the sync mutex, because some watchdog
3089 * drivers need to sleep while patting
3090 */
3091 mtx_unlock(&sync_mtx);
3092 wdog_kern_pat(WD_LASTVAL);
3093 mtx_lock(&sync_mtx);
3094 }
3095 }
3096 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
3097 syncer_final_iter--;
3098 /*
3099 * The variable rushjob allows the kernel to speed up the
3100 * processing of the filesystem syncer process. A rushjob
3101 * value of N tells the filesystem syncer to process the next
3102 * N seconds worth of work on its queue ASAP. Currently rushjob
3103 * is used by the soft update code to speed up the filesystem
3104 * syncer process when the incore state is getting so far
3105 * ahead of the disk that the kernel memory pool is being
3106 * threatened with exhaustion.
3107 */
3108 if (rushjob > 0) {
3109 rushjob -= 1;
3110 continue;
3111 }
3112 /*
3113 * Just sleep for a short period of time between
3114 * iterations when shutting down to allow some I/O
3115 * to happen.
3116 *
3117 * If it has taken us less than a second to process the
3118 * current work, then wait. Otherwise start right over
3119 * again. We can still lose time if any single round
3120 * takes more than two seconds, but it does not really
3121 * matter as we are just trying to generally pace the
3122 * filesystem activity.
3123 */
3124 if (syncer_state != SYNCER_RUNNING ||
3125 time_uptime == starttime) {
3126 thread_lock(td);
3127 sched_prio(td, PPAUSE);
3128 thread_unlock(td);
3129 }
3130 if (syncer_state != SYNCER_RUNNING)
3131 cv_timedwait(&sync_wakeup, &sync_mtx,
3132 hz / SYNCER_SHUTDOWN_SPEEDUP);
3133 else if (time_uptime == starttime)
3134 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
3135 }
3136 }
3137
3138 /*
3139 * Request the syncer daemon to speed up its work.
3140 * We never push it to speed up more than half of its
3141 * normal turn time, otherwise it could take over the cpu.
3142 */
3143 int
speedup_syncer(void)3144 speedup_syncer(void)
3145 {
3146 int ret = 0;
3147
3148 mtx_lock(&sync_mtx);
3149 if (rushjob < syncdelay / 2) {
3150 rushjob += 1;
3151 stat_rush_requests += 1;
3152 ret = 1;
3153 }
3154 mtx_unlock(&sync_mtx);
3155 cv_broadcast(&sync_wakeup);
3156 return (ret);
3157 }
3158
3159 /*
3160 * Tell the syncer to speed up its work and run though its work
3161 * list several times, then tell it to shut down.
3162 */
3163 static void
syncer_shutdown(void * arg,int howto)3164 syncer_shutdown(void *arg, int howto)
3165 {
3166
3167 if (howto & RB_NOSYNC)
3168 return;
3169 mtx_lock(&sync_mtx);
3170 syncer_state = SYNCER_SHUTTING_DOWN;
3171 rushjob = 0;
3172 mtx_unlock(&sync_mtx);
3173 cv_broadcast(&sync_wakeup);
3174 kproc_shutdown(arg, howto);
3175 }
3176
3177 void
syncer_suspend(void)3178 syncer_suspend(void)
3179 {
3180
3181 syncer_shutdown(updateproc, 0);
3182 }
3183
3184 void
syncer_resume(void)3185 syncer_resume(void)
3186 {
3187
3188 mtx_lock(&sync_mtx);
3189 first_printf = 1;
3190 syncer_state = SYNCER_RUNNING;
3191 mtx_unlock(&sync_mtx);
3192 cv_broadcast(&sync_wakeup);
3193 kproc_resume(updateproc);
3194 }
3195
3196 /*
3197 * Move the buffer between the clean and dirty lists of its vnode.
3198 */
3199 void
reassignbuf(struct buf * bp)3200 reassignbuf(struct buf *bp)
3201 {
3202 struct vnode *vp;
3203 struct bufobj *bo;
3204 int delay;
3205 #ifdef INVARIANTS
3206 struct bufv *bv;
3207 #endif
3208
3209 vp = bp->b_vp;
3210 bo = bp->b_bufobj;
3211
3212 KASSERT((bp->b_flags & B_PAGING) == 0,
3213 ("%s: cannot reassign paging buffer %p", __func__, bp));
3214
3215 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
3216 bp, bp->b_vp, bp->b_flags);
3217
3218 BO_LOCK(bo);
3219 if ((bo->bo_flag & BO_NONSTERILE) == 0) {
3220 /*
3221 * Coordinate with getblk's unlocked lookup. Make
3222 * BO_NONSTERILE visible before the first reassignbuf produces
3223 * any side effect. This could be outside the bo lock if we
3224 * used a separate atomic flag field.
3225 */
3226 bo->bo_flag |= BO_NONSTERILE;
3227 atomic_thread_fence_rel();
3228 }
3229 buf_vlist_remove(bp);
3230
3231 /*
3232 * If dirty, put on list of dirty buffers; otherwise insert onto list
3233 * of clean buffers.
3234 */
3235 if (bp->b_flags & B_DELWRI) {
3236 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
3237 switch (vp->v_type) {
3238 case VDIR:
3239 delay = dirdelay;
3240 break;
3241 case VCHR:
3242 delay = metadelay;
3243 break;
3244 default:
3245 delay = filedelay;
3246 }
3247 vn_syncer_add_to_worklist(bo, delay);
3248 }
3249 buf_vlist_add(bp, bo, BX_VNDIRTY);
3250 } else {
3251 buf_vlist_add(bp, bo, BX_VNCLEAN);
3252
3253 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
3254 mtx_lock(&sync_mtx);
3255 LIST_REMOVE(bo, bo_synclist);
3256 syncer_worklist_len--;
3257 mtx_unlock(&sync_mtx);
3258 bo->bo_flag &= ~BO_ONWORKLST;
3259 }
3260 }
3261 #ifdef INVARIANTS
3262 bv = &bo->bo_clean;
3263 bp = TAILQ_FIRST(&bv->bv_hd);
3264 KASSERT(bp == NULL || bp->b_bufobj == bo,
3265 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3266 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3267 KASSERT(bp == NULL || bp->b_bufobj == bo,
3268 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3269 bv = &bo->bo_dirty;
3270 bp = TAILQ_FIRST(&bv->bv_hd);
3271 KASSERT(bp == NULL || bp->b_bufobj == bo,
3272 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3273 bp = TAILQ_LAST(&bv->bv_hd, buflists);
3274 KASSERT(bp == NULL || bp->b_bufobj == bo,
3275 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
3276 #endif
3277 BO_UNLOCK(bo);
3278 }
3279
3280 static void
v_init_counters(struct vnode * vp)3281 v_init_counters(struct vnode *vp)
3282 {
3283
3284 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
3285 vp, ("%s called for an initialized vnode", __FUNCTION__));
3286 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
3287
3288 refcount_init(&vp->v_holdcnt, 1);
3289 refcount_init(&vp->v_usecount, 1);
3290 }
3291
3292 /*
3293 * Get a usecount on a vnode.
3294 *
3295 * vget and vget_finish may fail to lock the vnode if they lose a race against
3296 * it being doomed. LK_RETRY can be passed in flags to lock it anyway.
3297 *
3298 * Consumers which don't guarantee liveness of the vnode can use SMR to
3299 * try to get a reference. Note this operation can fail since the vnode
3300 * may be awaiting getting freed by the time they get to it.
3301 */
3302 enum vgetstate
vget_prep_smr(struct vnode * vp)3303 vget_prep_smr(struct vnode *vp)
3304 {
3305 enum vgetstate vs;
3306
3307 VFS_SMR_ASSERT_ENTERED();
3308
3309 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3310 vs = VGET_USECOUNT;
3311 } else {
3312 if (vhold_smr(vp))
3313 vs = VGET_HOLDCNT;
3314 else
3315 vs = VGET_NONE;
3316 }
3317 return (vs);
3318 }
3319
3320 enum vgetstate
vget_prep(struct vnode * vp)3321 vget_prep(struct vnode *vp)
3322 {
3323 enum vgetstate vs;
3324
3325 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
3326 vs = VGET_USECOUNT;
3327 } else {
3328 vhold(vp);
3329 vs = VGET_HOLDCNT;
3330 }
3331 return (vs);
3332 }
3333
3334 void
vget_abort(struct vnode * vp,enum vgetstate vs)3335 vget_abort(struct vnode *vp, enum vgetstate vs)
3336 {
3337
3338 switch (vs) {
3339 case VGET_USECOUNT:
3340 vrele(vp);
3341 break;
3342 case VGET_HOLDCNT:
3343 vdrop(vp);
3344 break;
3345 default:
3346 __assert_unreachable();
3347 }
3348 }
3349
3350 int
vget(struct vnode * vp,int flags)3351 vget(struct vnode *vp, int flags)
3352 {
3353 enum vgetstate vs;
3354
3355 vs = vget_prep(vp);
3356 return (vget_finish(vp, flags, vs));
3357 }
3358
3359 int
vget_finish(struct vnode * vp,int flags,enum vgetstate vs)3360 vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
3361 {
3362 int error;
3363
3364 if ((flags & LK_INTERLOCK) != 0)
3365 ASSERT_VI_LOCKED(vp, __func__);
3366 else
3367 ASSERT_VI_UNLOCKED(vp, __func__);
3368 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3369 VNPASS(vp->v_holdcnt > 0, vp);
3370 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3371
3372 error = vn_lock(vp, flags);
3373 if (__predict_false(error != 0)) {
3374 vget_abort(vp, vs);
3375 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
3376 vp);
3377 return (error);
3378 }
3379
3380 vget_finish_ref(vp, vs);
3381 return (0);
3382 }
3383
3384 void
vget_finish_ref(struct vnode * vp,enum vgetstate vs)3385 vget_finish_ref(struct vnode *vp, enum vgetstate vs)
3386 {
3387 int old;
3388
3389 VNPASS(vs == VGET_HOLDCNT || vs == VGET_USECOUNT, vp);
3390 VNPASS(vp->v_holdcnt > 0, vp);
3391 VNPASS(vs == VGET_HOLDCNT || vp->v_usecount > 0, vp);
3392
3393 if (vs == VGET_USECOUNT)
3394 return;
3395
3396 /*
3397 * We hold the vnode. If the usecount is 0 it will be utilized to keep
3398 * the vnode around. Otherwise someone else lended their hold count and
3399 * we have to drop ours.
3400 */
3401 old = atomic_fetchadd_int(&vp->v_usecount, 1);
3402 VNASSERT(old >= 0, vp, ("%s: wrong use count %d", __func__, old));
3403 if (old != 0) {
3404 #ifdef INVARIANTS
3405 old = atomic_fetchadd_int(&vp->v_holdcnt, -1);
3406 VNASSERT(old > 1, vp, ("%s: wrong hold count %d", __func__, old));
3407 #else
3408 refcount_release(&vp->v_holdcnt);
3409 #endif
3410 }
3411 }
3412
3413 void
vref(struct vnode * vp)3414 vref(struct vnode *vp)
3415 {
3416 enum vgetstate vs;
3417
3418 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3419 vs = vget_prep(vp);
3420 vget_finish_ref(vp, vs);
3421 }
3422
3423 void
vrefact(struct vnode * vp)3424 vrefact(struct vnode *vp)
3425 {
3426 int old __diagused;
3427
3428 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3429 old = refcount_acquire(&vp->v_usecount);
3430 VNASSERT(old > 0, vp, ("%s: wrong use count %d", __func__, old));
3431 }
3432
3433 void
vlazy(struct vnode * vp)3434 vlazy(struct vnode *vp)
3435 {
3436 struct mount *mp;
3437
3438 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__));
3439
3440 if ((vp->v_mflag & VMP_LAZYLIST) != 0)
3441 return;
3442 /*
3443 * We may get here for inactive routines after the vnode got doomed.
3444 */
3445 if (VN_IS_DOOMED(vp))
3446 return;
3447 mp = vp->v_mount;
3448 mtx_lock(&mp->mnt_listmtx);
3449 if ((vp->v_mflag & VMP_LAZYLIST) == 0) {
3450 vp->v_mflag |= VMP_LAZYLIST;
3451 TAILQ_INSERT_TAIL(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3452 mp->mnt_lazyvnodelistsize++;
3453 }
3454 mtx_unlock(&mp->mnt_listmtx);
3455 }
3456
3457 static void
vunlazy(struct vnode * vp)3458 vunlazy(struct vnode *vp)
3459 {
3460 struct mount *mp;
3461
3462 ASSERT_VI_LOCKED(vp, __func__);
3463 VNPASS(!VN_IS_DOOMED(vp), vp);
3464
3465 mp = vp->v_mount;
3466 mtx_lock(&mp->mnt_listmtx);
3467 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3468 /*
3469 * Don't remove the vnode from the lazy list if another thread
3470 * has increased the hold count. It may have re-enqueued the
3471 * vnode to the lazy list and is now responsible for its
3472 * removal.
3473 */
3474 if (vp->v_holdcnt == 0) {
3475 vp->v_mflag &= ~VMP_LAZYLIST;
3476 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3477 mp->mnt_lazyvnodelistsize--;
3478 }
3479 mtx_unlock(&mp->mnt_listmtx);
3480 }
3481
3482 /*
3483 * This routine is only meant to be called from vgonel prior to dooming
3484 * the vnode.
3485 */
3486 static void
vunlazy_gone(struct vnode * vp)3487 vunlazy_gone(struct vnode *vp)
3488 {
3489 struct mount *mp;
3490
3491 ASSERT_VOP_ELOCKED(vp, __func__);
3492 ASSERT_VI_LOCKED(vp, __func__);
3493 VNPASS(!VN_IS_DOOMED(vp), vp);
3494
3495 if (vp->v_mflag & VMP_LAZYLIST) {
3496 mp = vp->v_mount;
3497 mtx_lock(&mp->mnt_listmtx);
3498 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
3499 vp->v_mflag &= ~VMP_LAZYLIST;
3500 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, vp, v_lazylist);
3501 mp->mnt_lazyvnodelistsize--;
3502 mtx_unlock(&mp->mnt_listmtx);
3503 }
3504 }
3505
3506 static void
vdefer_inactive(struct vnode * vp)3507 vdefer_inactive(struct vnode *vp)
3508 {
3509
3510 ASSERT_VI_LOCKED(vp, __func__);
3511 VNPASS(vp->v_holdcnt > 0, vp);
3512 if (VN_IS_DOOMED(vp)) {
3513 vdropl(vp);
3514 return;
3515 }
3516 if (vp->v_iflag & VI_DEFINACT) {
3517 VNPASS(vp->v_holdcnt > 1, vp);
3518 vdropl(vp);
3519 return;
3520 }
3521 if (vp->v_usecount > 0) {
3522 vp->v_iflag &= ~VI_OWEINACT;
3523 vdropl(vp);
3524 return;
3525 }
3526 vlazy(vp);
3527 vp->v_iflag |= VI_DEFINACT;
3528 VI_UNLOCK(vp);
3529 atomic_add_long(&deferred_inact, 1);
3530 }
3531
3532 static void
vdefer_inactive_unlocked(struct vnode * vp)3533 vdefer_inactive_unlocked(struct vnode *vp)
3534 {
3535
3536 VI_LOCK(vp);
3537 if ((vp->v_iflag & VI_OWEINACT) == 0) {
3538 vdropl(vp);
3539 return;
3540 }
3541 vdefer_inactive(vp);
3542 }
3543
3544 enum vput_op { VRELE, VPUT, VUNREF };
3545
3546 /*
3547 * Handle ->v_usecount transitioning to 0.
3548 *
3549 * By releasing the last usecount we take ownership of the hold count which
3550 * provides liveness of the vnode, meaning we have to vdrop.
3551 *
3552 * For all vnodes we may need to perform inactive processing. It requires an
3553 * exclusive lock on the vnode, while it is legal to call here with only a
3554 * shared lock (or no locks). If locking the vnode in an expected manner fails,
3555 * inactive processing gets deferred to the syncer.
3556 *
3557 * XXX Some filesystems pass in an exclusively locked vnode and strongly depend
3558 * on the lock being held all the way until VOP_INACTIVE. This in particular
3559 * happens with UFS which adds half-constructed vnodes to the hash, where they
3560 * can be found by other code.
3561 */
3562 static void
vput_final(struct vnode * vp,enum vput_op func)3563 vput_final(struct vnode *vp, enum vput_op func)
3564 {
3565 int error;
3566 bool want_unlock;
3567
3568 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3569 VNPASS(vp->v_holdcnt > 0, vp);
3570
3571 VI_LOCK(vp);
3572
3573 /*
3574 * By the time we got here someone else might have transitioned
3575 * the count back to > 0.
3576 */
3577 if (vp->v_usecount > 0)
3578 goto out;
3579
3580 /*
3581 * If the vnode is doomed vgone already performed inactive processing
3582 * (if needed).
3583 */
3584 if (VN_IS_DOOMED(vp))
3585 goto out;
3586
3587 if (__predict_true(VOP_NEED_INACTIVE(vp) == 0))
3588 goto out;
3589
3590 if (vp->v_iflag & VI_DOINGINACT)
3591 goto out;
3592
3593 /*
3594 * Locking operations here will drop the interlock and possibly the
3595 * vnode lock, opening a window where the vnode can get doomed all the
3596 * while ->v_usecount is 0. Set VI_OWEINACT to let vgone know to
3597 * perform inactive.
3598 */
3599 vp->v_iflag |= VI_OWEINACT;
3600 want_unlock = false;
3601 error = 0;
3602 switch (func) {
3603 case VRELE:
3604 switch (VOP_ISLOCKED(vp)) {
3605 case LK_EXCLUSIVE:
3606 break;
3607 case LK_EXCLOTHER:
3608 case 0:
3609 want_unlock = true;
3610 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
3611 VI_LOCK(vp);
3612 break;
3613 default:
3614 /*
3615 * The lock has at least one sharer, but we have no way
3616 * to conclude whether this is us. Play it safe and
3617 * defer processing.
3618 */
3619 error = EAGAIN;
3620 break;
3621 }
3622 break;
3623 case VPUT:
3624 want_unlock = true;
3625 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3626 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
3627 LK_NOWAIT);
3628 VI_LOCK(vp);
3629 }
3630 break;
3631 case VUNREF:
3632 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3633 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
3634 VI_LOCK(vp);
3635 }
3636 break;
3637 }
3638 if (error == 0) {
3639 if (func == VUNREF) {
3640 VNASSERT((vp->v_vflag & VV_UNREF) == 0, vp,
3641 ("recursive vunref"));
3642 vp->v_vflag |= VV_UNREF;
3643 }
3644 for (;;) {
3645 error = vinactive(vp);
3646 if (want_unlock)
3647 VOP_UNLOCK(vp);
3648 if (error != ERELOOKUP || !want_unlock)
3649 break;
3650 VOP_LOCK(vp, LK_EXCLUSIVE);
3651 }
3652 if (func == VUNREF)
3653 vp->v_vflag &= ~VV_UNREF;
3654 vdropl(vp);
3655 } else {
3656 vdefer_inactive(vp);
3657 }
3658 return;
3659 out:
3660 if (func == VPUT)
3661 VOP_UNLOCK(vp);
3662 vdropl(vp);
3663 }
3664
3665 /*
3666 * Decrement ->v_usecount for a vnode.
3667 *
3668 * Releasing the last use count requires additional processing, see vput_final
3669 * above for details.
3670 *
3671 * Comment above each variant denotes lock state on entry and exit.
3672 */
3673
3674 /*
3675 * in: any
3676 * out: same as passed in
3677 */
3678 void
vrele(struct vnode * vp)3679 vrele(struct vnode *vp)
3680 {
3681
3682 ASSERT_VI_UNLOCKED(vp, __func__);
3683 if (!refcount_release(&vp->v_usecount))
3684 return;
3685 vput_final(vp, VRELE);
3686 }
3687
3688 /*
3689 * in: locked
3690 * out: unlocked
3691 */
3692 void
vput(struct vnode * vp)3693 vput(struct vnode *vp)
3694 {
3695
3696 ASSERT_VOP_LOCKED(vp, __func__);
3697 ASSERT_VI_UNLOCKED(vp, __func__);
3698 if (!refcount_release(&vp->v_usecount)) {
3699 VOP_UNLOCK(vp);
3700 return;
3701 }
3702 vput_final(vp, VPUT);
3703 }
3704
3705 /*
3706 * in: locked
3707 * out: locked
3708 */
3709 void
vunref(struct vnode * vp)3710 vunref(struct vnode *vp)
3711 {
3712
3713 ASSERT_VOP_LOCKED(vp, __func__);
3714 ASSERT_VI_UNLOCKED(vp, __func__);
3715 if (!refcount_release(&vp->v_usecount))
3716 return;
3717 vput_final(vp, VUNREF);
3718 }
3719
3720 void
vhold(struct vnode * vp)3721 vhold(struct vnode *vp)
3722 {
3723 int old;
3724
3725 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3726 old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3727 VNASSERT(old >= 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3728 ("%s: wrong hold count %d", __func__, old));
3729 if (old == 0)
3730 vfs_freevnodes_dec();
3731 }
3732
3733 void
vholdnz(struct vnode * vp)3734 vholdnz(struct vnode *vp)
3735 {
3736
3737 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3738 #ifdef INVARIANTS
3739 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3740 VNASSERT(old > 0 && (old & VHOLD_ALL_FLAGS) == 0, vp,
3741 ("%s: wrong hold count %d", __func__, old));
3742 #else
3743 atomic_add_int(&vp->v_holdcnt, 1);
3744 #endif
3745 }
3746
3747 /*
3748 * Grab a hold count unless the vnode is freed.
3749 *
3750 * Only use this routine if vfs smr is the only protection you have against
3751 * freeing the vnode.
3752 *
3753 * The code loops trying to add a hold count as long as the VHOLD_NO_SMR flag
3754 * is not set. After the flag is set the vnode becomes immutable to anyone but
3755 * the thread which managed to set the flag.
3756 *
3757 * It may be tempting to replace the loop with:
3758 * count = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3759 * if (count & VHOLD_NO_SMR) {
3760 * backpedal and error out;
3761 * }
3762 *
3763 * However, while this is more performant, it hinders debugging by eliminating
3764 * the previously mentioned invariant.
3765 */
3766 bool
vhold_smr(struct vnode * vp)3767 vhold_smr(struct vnode *vp)
3768 {
3769 int count;
3770
3771 VFS_SMR_ASSERT_ENTERED();
3772
3773 count = atomic_load_int(&vp->v_holdcnt);
3774 for (;;) {
3775 if (count & VHOLD_NO_SMR) {
3776 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3777 ("non-zero hold count with flags %d\n", count));
3778 return (false);
3779 }
3780 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3781 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3782 if (count == 0)
3783 vfs_freevnodes_dec();
3784 return (true);
3785 }
3786 }
3787 }
3788
3789 /*
3790 * Hold a free vnode for recycling.
3791 *
3792 * Note: vnode_init references this comment.
3793 *
3794 * Attempts to recycle only need the global vnode list lock and have no use for
3795 * SMR.
3796 *
3797 * However, vnodes get inserted into the global list before they get fully
3798 * initialized and stay there until UMA decides to free the memory. This in
3799 * particular means the target can be found before it becomes usable and after
3800 * it becomes recycled. Picking up such vnodes is guarded with v_holdcnt set to
3801 * VHOLD_NO_SMR.
3802 *
3803 * Note: the vnode may gain more references after we transition the count 0->1.
3804 */
3805 static bool
vhold_recycle_free(struct vnode * vp)3806 vhold_recycle_free(struct vnode *vp)
3807 {
3808 int count;
3809
3810 mtx_assert(&vnode_list_mtx, MA_OWNED);
3811
3812 count = atomic_load_int(&vp->v_holdcnt);
3813 for (;;) {
3814 if (count & VHOLD_NO_SMR) {
3815 VNASSERT((count & ~VHOLD_NO_SMR) == 0, vp,
3816 ("non-zero hold count with flags %d\n", count));
3817 return (false);
3818 }
3819 VNASSERT(count >= 0, vp, ("invalid hold count %d\n", count));
3820 if (count > 0) {
3821 return (false);
3822 }
3823 if (atomic_fcmpset_int(&vp->v_holdcnt, &count, count + 1)) {
3824 vfs_freevnodes_dec();
3825 return (true);
3826 }
3827 }
3828 }
3829
3830 static void __noinline
vdbatch_process(struct vdbatch * vd)3831 vdbatch_process(struct vdbatch *vd)
3832 {
3833 struct vnode *vp;
3834 int i;
3835
3836 mtx_assert(&vd->lock, MA_OWNED);
3837 MPASS(curthread->td_pinned > 0);
3838 MPASS(vd->index == VDBATCH_SIZE);
3839
3840 /*
3841 * Attempt to requeue the passed batch, but give up easily.
3842 *
3843 * Despite batching the mechanism is prone to transient *significant*
3844 * lock contention, where vnode_list_mtx becomes the primary bottleneck
3845 * if multiple CPUs get here (one real-world example is highly parallel
3846 * do-nothing make , which will stat *tons* of vnodes). Since it is
3847 * quasi-LRU (read: not that great even if fully honoured) provide an
3848 * option to just dodge the problem. Parties which don't like it are
3849 * welcome to implement something better.
3850 */
3851 if (vnode_can_skip_requeue) {
3852 if (!mtx_trylock(&vnode_list_mtx)) {
3853 counter_u64_add(vnode_skipped_requeues, 1);
3854 critical_enter();
3855 for (i = 0; i < VDBATCH_SIZE; i++) {
3856 vp = vd->tab[i];
3857 vd->tab[i] = NULL;
3858 MPASS(vp->v_dbatchcpu != NOCPU);
3859 vp->v_dbatchcpu = NOCPU;
3860 }
3861 vd->index = 0;
3862 critical_exit();
3863 return;
3864
3865 }
3866 /* fallthrough to locked processing */
3867 } else {
3868 mtx_lock(&vnode_list_mtx);
3869 }
3870
3871 mtx_assert(&vnode_list_mtx, MA_OWNED);
3872 critical_enter();
3873 for (i = 0; i < VDBATCH_SIZE; i++) {
3874 vp = vd->tab[i];
3875 vd->tab[i] = NULL;
3876 TAILQ_REMOVE(&vnode_list, vp, v_vnodelist);
3877 TAILQ_INSERT_TAIL(&vnode_list, vp, v_vnodelist);
3878 MPASS(vp->v_dbatchcpu != NOCPU);
3879 vp->v_dbatchcpu = NOCPU;
3880 }
3881 mtx_unlock(&vnode_list_mtx);
3882 vd->index = 0;
3883 critical_exit();
3884 }
3885
3886 static void
vdbatch_enqueue(struct vnode * vp)3887 vdbatch_enqueue(struct vnode *vp)
3888 {
3889 struct vdbatch *vd;
3890
3891 ASSERT_VI_LOCKED(vp, __func__);
3892 VNPASS(!VN_IS_DOOMED(vp), vp);
3893
3894 if (vp->v_dbatchcpu != NOCPU) {
3895 VI_UNLOCK(vp);
3896 return;
3897 }
3898
3899 sched_pin();
3900 vd = DPCPU_PTR(vd);
3901 mtx_lock(&vd->lock);
3902 MPASS(vd->index < VDBATCH_SIZE);
3903 MPASS(vd->tab[vd->index] == NULL);
3904 /*
3905 * A hack: we depend on being pinned so that we know what to put in
3906 * ->v_dbatchcpu.
3907 */
3908 vp->v_dbatchcpu = curcpu;
3909 vd->tab[vd->index] = vp;
3910 vd->index++;
3911 VI_UNLOCK(vp);
3912 if (vd->index == VDBATCH_SIZE)
3913 vdbatch_process(vd);
3914 mtx_unlock(&vd->lock);
3915 sched_unpin();
3916 }
3917
3918 /*
3919 * This routine must only be called for vnodes which are about to be
3920 * deallocated. Supporting dequeue for arbitrary vndoes would require
3921 * validating that the locked batch matches.
3922 */
3923 static void
vdbatch_dequeue(struct vnode * vp)3924 vdbatch_dequeue(struct vnode *vp)
3925 {
3926 struct vdbatch *vd;
3927 int i;
3928 short cpu;
3929
3930 VNPASS(vp->v_type == VBAD || vp->v_type == VNON, vp);
3931
3932 cpu = vp->v_dbatchcpu;
3933 if (cpu == NOCPU)
3934 return;
3935
3936 vd = DPCPU_ID_PTR(cpu, vd);
3937 mtx_lock(&vd->lock);
3938 for (i = 0; i < vd->index; i++) {
3939 if (vd->tab[i] != vp)
3940 continue;
3941 vp->v_dbatchcpu = NOCPU;
3942 vd->index--;
3943 vd->tab[i] = vd->tab[vd->index];
3944 vd->tab[vd->index] = NULL;
3945 break;
3946 }
3947 mtx_unlock(&vd->lock);
3948 /*
3949 * Either we dequeued the vnode above or the target CPU beat us to it.
3950 */
3951 MPASS(vp->v_dbatchcpu == NOCPU);
3952 }
3953
3954 /*
3955 * Drop the hold count of the vnode.
3956 *
3957 * It will only get freed if this is the last hold *and* it has been vgone'd.
3958 *
3959 * Because the vnode vm object keeps a hold reference on the vnode if
3960 * there is at least one resident non-cached page, the vnode cannot
3961 * leave the active list without the page cleanup done.
3962 */
3963 static void __noinline
vdropl_final(struct vnode * vp)3964 vdropl_final(struct vnode *vp)
3965 {
3966
3967 ASSERT_VI_LOCKED(vp, __func__);
3968 VNPASS(VN_IS_DOOMED(vp), vp);
3969 /*
3970 * Set the VHOLD_NO_SMR flag.
3971 *
3972 * We may be racing against vhold_smr. If they win we can just pretend
3973 * we never got this far, they will vdrop later.
3974 */
3975 if (__predict_false(!atomic_cmpset_int(&vp->v_holdcnt, 0, VHOLD_NO_SMR))) {
3976 vfs_freevnodes_inc();
3977 VI_UNLOCK(vp);
3978 /*
3979 * We lost the aforementioned race. Any subsequent access is
3980 * invalid as they might have managed to vdropl on their own.
3981 */
3982 return;
3983 }
3984 /*
3985 * Don't bump freevnodes as this one is going away.
3986 */
3987 freevnode(vp);
3988 }
3989
3990 void
vdrop(struct vnode * vp)3991 vdrop(struct vnode *vp)
3992 {
3993
3994 ASSERT_VI_UNLOCKED(vp, __func__);
3995 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3996 if (refcount_release_if_not_last(&vp->v_holdcnt))
3997 return;
3998 VI_LOCK(vp);
3999 vdropl(vp);
4000 }
4001
4002 static __always_inline void
vdropl_impl(struct vnode * vp,bool enqueue)4003 vdropl_impl(struct vnode *vp, bool enqueue)
4004 {
4005
4006 ASSERT_VI_LOCKED(vp, __func__);
4007 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4008 if (!refcount_release(&vp->v_holdcnt)) {
4009 VI_UNLOCK(vp);
4010 return;
4011 }
4012 VNPASS((vp->v_iflag & VI_OWEINACT) == 0, vp);
4013 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
4014 if (VN_IS_DOOMED(vp)) {
4015 vdropl_final(vp);
4016 return;
4017 }
4018
4019 vfs_freevnodes_inc();
4020 if (vp->v_mflag & VMP_LAZYLIST) {
4021 vunlazy(vp);
4022 }
4023
4024 if (!enqueue) {
4025 VI_UNLOCK(vp);
4026 return;
4027 }
4028
4029 /*
4030 * Also unlocks the interlock. We can't assert on it as we
4031 * released our hold and by now the vnode might have been
4032 * freed.
4033 */
4034 vdbatch_enqueue(vp);
4035 }
4036
4037 void
vdropl(struct vnode * vp)4038 vdropl(struct vnode *vp)
4039 {
4040
4041 vdropl_impl(vp, true);
4042 }
4043
4044 /*
4045 * vdrop a vnode when recycling
4046 *
4047 * This is a special case routine only to be used when recycling, differs from
4048 * regular vdrop by not requeieing the vnode on LRU.
4049 *
4050 * Consider a case where vtryrecycle continuously fails with all vnodes (due to
4051 * e.g., frozen writes on the filesystem), filling the batch and causing it to
4052 * be requeued. Then vnlru will end up revisiting the same vnodes. This is a
4053 * loop which can last for as long as writes are frozen.
4054 */
4055 static void
vdropl_recycle(struct vnode * vp)4056 vdropl_recycle(struct vnode *vp)
4057 {
4058
4059 vdropl_impl(vp, false);
4060 }
4061
4062 static void
vdrop_recycle(struct vnode * vp)4063 vdrop_recycle(struct vnode *vp)
4064 {
4065
4066 VI_LOCK(vp);
4067 vdropl_recycle(vp);
4068 }
4069
4070 /*
4071 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
4072 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
4073 */
4074 static int
vinactivef(struct vnode * vp)4075 vinactivef(struct vnode *vp)
4076 {
4077 int error;
4078
4079 ASSERT_VOP_ELOCKED(vp, "vinactive");
4080 ASSERT_VI_LOCKED(vp, "vinactive");
4081 VNPASS((vp->v_iflag & VI_DOINGINACT) == 0, vp);
4082 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4083 vp->v_iflag |= VI_DOINGINACT;
4084 vp->v_iflag &= ~VI_OWEINACT;
4085 VI_UNLOCK(vp);
4086
4087 /*
4088 * Before moving off the active list, we must be sure that any
4089 * modified pages are converted into the vnode's dirty
4090 * buffers, since these will no longer be checked once the
4091 * vnode is on the inactive list.
4092 *
4093 * The write-out of the dirty pages is asynchronous. At the
4094 * point that VOP_INACTIVE() is called, there could still be
4095 * pending I/O and dirty pages in the object.
4096 */
4097 if ((vp->v_vflag & VV_NOSYNC) == 0)
4098 vnode_pager_clean_async(vp);
4099
4100 error = VOP_INACTIVE(vp);
4101 VI_LOCK(vp);
4102 VNPASS(vp->v_iflag & VI_DOINGINACT, vp);
4103 vp->v_iflag &= ~VI_DOINGINACT;
4104 return (error);
4105 }
4106
4107 int
vinactive(struct vnode * vp)4108 vinactive(struct vnode *vp)
4109 {
4110
4111 ASSERT_VOP_ELOCKED(vp, "vinactive");
4112 ASSERT_VI_LOCKED(vp, "vinactive");
4113 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4114
4115 if ((vp->v_iflag & VI_OWEINACT) == 0)
4116 return (0);
4117 if (vp->v_iflag & VI_DOINGINACT)
4118 return (0);
4119 if (vp->v_usecount > 0) {
4120 vp->v_iflag &= ~VI_OWEINACT;
4121 return (0);
4122 }
4123 return (vinactivef(vp));
4124 }
4125
4126 /*
4127 * Remove any vnodes in the vnode table belonging to mount point mp.
4128 *
4129 * If FORCECLOSE is not specified, there should not be any active ones,
4130 * return error if any are found (nb: this is a user error, not a
4131 * system error). If FORCECLOSE is specified, detach any active vnodes
4132 * that are found.
4133 *
4134 * If WRITECLOSE is set, only flush out regular file vnodes open for
4135 * writing.
4136 *
4137 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
4138 *
4139 * `rootrefs' specifies the base reference count for the root vnode
4140 * of this filesystem. The root vnode is considered busy if its
4141 * v_usecount exceeds this value. On a successful return, vflush(, td)
4142 * will call vrele() on the root vnode exactly rootrefs times.
4143 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
4144 * be zero.
4145 */
4146 #ifdef DIAGNOSTIC
4147 static int busyprt = 0; /* print out busy vnodes */
4148 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
4149 #endif
4150
4151 int
vflush(struct mount * mp,int rootrefs,int flags,struct thread * td)4152 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
4153 {
4154 struct vnode *vp, *mvp, *rootvp = NULL;
4155 struct vattr vattr;
4156 int busy = 0, error;
4157
4158 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
4159 rootrefs, flags);
4160 if (rootrefs > 0) {
4161 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
4162 ("vflush: bad args"));
4163 /*
4164 * Get the filesystem root vnode. We can vput() it
4165 * immediately, since with rootrefs > 0, it won't go away.
4166 */
4167 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
4168 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
4169 __func__, error);
4170 return (error);
4171 }
4172 vput(rootvp);
4173 }
4174 loop:
4175 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
4176 vholdl(vp);
4177 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
4178 if (error) {
4179 vdrop(vp);
4180 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4181 goto loop;
4182 }
4183 /*
4184 * Skip over a vnodes marked VV_SYSTEM.
4185 */
4186 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
4187 VOP_UNLOCK(vp);
4188 vdrop(vp);
4189 continue;
4190 }
4191 /*
4192 * If WRITECLOSE is set, flush out unlinked but still open
4193 * files (even if open only for reading) and regular file
4194 * vnodes open for writing.
4195 */
4196 if (flags & WRITECLOSE) {
4197 vnode_pager_clean_async(vp);
4198 do {
4199 error = VOP_FSYNC(vp, MNT_WAIT, td);
4200 } while (error == ERELOOKUP);
4201 if (error != 0) {
4202 VOP_UNLOCK(vp);
4203 vdrop(vp);
4204 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
4205 return (error);
4206 }
4207 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4208 VI_LOCK(vp);
4209
4210 if ((vp->v_type == VNON ||
4211 (error == 0 && vattr.va_nlink > 0)) &&
4212 (vp->v_writecount <= 0 || vp->v_type != VREG)) {
4213 VOP_UNLOCK(vp);
4214 vdropl(vp);
4215 continue;
4216 }
4217 } else
4218 VI_LOCK(vp);
4219 /*
4220 * With v_usecount == 0, all we need to do is clear out the
4221 * vnode data structures and we are done.
4222 *
4223 * If FORCECLOSE is set, forcibly close the vnode.
4224 */
4225 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
4226 vgonel(vp);
4227 } else {
4228 busy++;
4229 #ifdef DIAGNOSTIC
4230 if (busyprt)
4231 vn_printf(vp, "vflush: busy vnode ");
4232 #endif
4233 }
4234 VOP_UNLOCK(vp);
4235 vdropl(vp);
4236 }
4237 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
4238 /*
4239 * If just the root vnode is busy, and if its refcount
4240 * is equal to `rootrefs', then go ahead and kill it.
4241 */
4242 VI_LOCK(rootvp);
4243 KASSERT(busy > 0, ("vflush: not busy"));
4244 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
4245 ("vflush: usecount %d < rootrefs %d",
4246 rootvp->v_usecount, rootrefs));
4247 if (busy == 1 && rootvp->v_usecount == rootrefs) {
4248 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
4249 vgone(rootvp);
4250 VOP_UNLOCK(rootvp);
4251 busy = 0;
4252 } else
4253 VI_UNLOCK(rootvp);
4254 }
4255 if (busy) {
4256 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
4257 busy);
4258 return (EBUSY);
4259 }
4260 for (; rootrefs > 0; rootrefs--)
4261 vrele(rootvp);
4262 return (0);
4263 }
4264
4265 /*
4266 * Recycle an unused vnode.
4267 */
4268 int
vrecycle(struct vnode * vp)4269 vrecycle(struct vnode *vp)
4270 {
4271 int recycled;
4272
4273 VI_LOCK(vp);
4274 recycled = vrecyclel(vp);
4275 VI_UNLOCK(vp);
4276 return (recycled);
4277 }
4278
4279 /*
4280 * vrecycle, with the vp interlock held.
4281 */
4282 int
vrecyclel(struct vnode * vp)4283 vrecyclel(struct vnode *vp)
4284 {
4285 int recycled;
4286
4287 ASSERT_VOP_ELOCKED(vp, __func__);
4288 ASSERT_VI_LOCKED(vp, __func__);
4289 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4290 recycled = 0;
4291 if (vp->v_usecount == 0) {
4292 recycled = 1;
4293 vgonel(vp);
4294 }
4295 return (recycled);
4296 }
4297
4298 /*
4299 * Eliminate all activity associated with a vnode
4300 * in preparation for reuse.
4301 */
4302 void
vgone(struct vnode * vp)4303 vgone(struct vnode *vp)
4304 {
4305 VI_LOCK(vp);
4306 vgonel(vp);
4307 VI_UNLOCK(vp);
4308 }
4309
4310 /*
4311 * Notify upper mounts about reclaimed or unlinked vnode.
4312 */
4313 void
vfs_notify_upper(struct vnode * vp,enum vfs_notify_upper_type event)4314 vfs_notify_upper(struct vnode *vp, enum vfs_notify_upper_type event)
4315 {
4316 struct mount *mp;
4317 struct mount_upper_node *ump;
4318
4319 mp = atomic_load_ptr(&vp->v_mount);
4320 if (mp == NULL)
4321 return;
4322 if (TAILQ_EMPTY(&mp->mnt_notify))
4323 return;
4324
4325 MNT_ILOCK(mp);
4326 mp->mnt_upper_pending++;
4327 KASSERT(mp->mnt_upper_pending > 0,
4328 ("%s: mnt_upper_pending %d", __func__, mp->mnt_upper_pending));
4329 TAILQ_FOREACH(ump, &mp->mnt_notify, mnt_upper_link) {
4330 MNT_IUNLOCK(mp);
4331 switch (event) {
4332 case VFS_NOTIFY_UPPER_RECLAIM:
4333 VFS_RECLAIM_LOWERVP(ump->mp, vp);
4334 break;
4335 case VFS_NOTIFY_UPPER_UNLINK:
4336 VFS_UNLINK_LOWERVP(ump->mp, vp);
4337 break;
4338 }
4339 MNT_ILOCK(mp);
4340 }
4341 mp->mnt_upper_pending--;
4342 if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 &&
4343 mp->mnt_upper_pending == 0) {
4344 mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER;
4345 wakeup(&mp->mnt_uppers);
4346 }
4347 MNT_IUNLOCK(mp);
4348 }
4349
4350 /*
4351 * vgone, with the vp interlock held.
4352 */
4353 static void
vgonel(struct vnode * vp)4354 vgonel(struct vnode *vp)
4355 {
4356 struct thread *td;
4357 struct mount *mp;
4358 vm_object_t object;
4359 bool active, doinginact, oweinact;
4360
4361 ASSERT_VOP_ELOCKED(vp, "vgonel");
4362 ASSERT_VI_LOCKED(vp, "vgonel");
4363 VNASSERT(vp->v_holdcnt, vp,
4364 ("vgonel: vp %p has no reference.", vp));
4365 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
4366 td = curthread;
4367
4368 /*
4369 * Don't vgonel if we're already doomed.
4370 */
4371 if (VN_IS_DOOMED(vp)) {
4372 VNPASS(vn_get_state(vp) == VSTATE_DESTROYING || \
4373 vn_get_state(vp) == VSTATE_DEAD, vp);
4374 return;
4375 }
4376 /*
4377 * Paired with freevnode.
4378 */
4379 vn_seqc_write_begin_locked(vp);
4380 vunlazy_gone(vp);
4381 vn_irflag_set_locked(vp, VIRF_DOOMED);
4382 vn_set_state(vp, VSTATE_DESTROYING);
4383
4384 /*
4385 * Check to see if the vnode is in use. If so, we have to
4386 * call VOP_CLOSE() and VOP_INACTIVE().
4387 *
4388 * It could be that VOP_INACTIVE() requested reclamation, in
4389 * which case we should avoid recursion, so check
4390 * VI_DOINGINACT. This is not precise but good enough.
4391 */
4392 active = vp->v_usecount > 0;
4393 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4394 doinginact = (vp->v_iflag & VI_DOINGINACT) != 0;
4395
4396 /*
4397 * If we need to do inactive VI_OWEINACT will be set.
4398 */
4399 if (vp->v_iflag & VI_DEFINACT) {
4400 VNASSERT(vp->v_holdcnt > 1, vp, ("lost hold count"));
4401 vp->v_iflag &= ~VI_DEFINACT;
4402 vdropl(vp);
4403 } else {
4404 VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count"));
4405 VI_UNLOCK(vp);
4406 }
4407 cache_purge_vgone(vp);
4408 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
4409
4410 /*
4411 * If purging an active vnode, it must be closed and
4412 * deactivated before being reclaimed.
4413 */
4414 if (active)
4415 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
4416 if (!doinginact) {
4417 do {
4418 if (oweinact || active) {
4419 VI_LOCK(vp);
4420 vinactivef(vp);
4421 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
4422 VI_UNLOCK(vp);
4423 }
4424 } while (oweinact);
4425 }
4426 if (vp->v_type == VSOCK)
4427 vfs_unp_reclaim(vp);
4428
4429 /*
4430 * Clean out any buffers associated with the vnode.
4431 * If the flush fails, just toss the buffers.
4432 */
4433 mp = NULL;
4434 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
4435 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
4436 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
4437 while (vinvalbuf(vp, 0, 0, 0) != 0)
4438 ;
4439 }
4440
4441 BO_LOCK(&vp->v_bufobj);
4442 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
4443 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
4444 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
4445 vp->v_bufobj.bo_clean.bv_cnt == 0,
4446 ("vp %p bufobj not invalidated", vp));
4447
4448 /*
4449 * For VMIO bufobj, BO_DEAD is set later, or in
4450 * vm_object_terminate() after the object's page queue is
4451 * flushed.
4452 */
4453 object = vp->v_bufobj.bo_object;
4454 if (object == NULL)
4455 vp->v_bufobj.bo_flag |= BO_DEAD;
4456 BO_UNLOCK(&vp->v_bufobj);
4457
4458 /*
4459 * Handle the VM part. Tmpfs handles v_object on its own (the
4460 * OBJT_VNODE check). Nullfs or other bypassing filesystems
4461 * should not touch the object borrowed from the lower vnode
4462 * (the handle check).
4463 */
4464 if (object != NULL && object->type == OBJT_VNODE &&
4465 object->handle == vp)
4466 vnode_destroy_vobject(vp);
4467
4468 /*
4469 * Reclaim the vnode.
4470 */
4471 if (VOP_RECLAIM(vp))
4472 panic("vgone: cannot reclaim");
4473 if (mp != NULL)
4474 vn_finished_secondary_write(mp);
4475 VNASSERT(vp->v_object == NULL, vp,
4476 ("vop_reclaim left v_object vp=%p", vp));
4477 /*
4478 * Clear the advisory locks and wake up waiting threads.
4479 */
4480 if (vp->v_lockf != NULL) {
4481 (void)VOP_ADVLOCKPURGE(vp);
4482 vp->v_lockf = NULL;
4483 }
4484 /*
4485 * Delete from old mount point vnode list.
4486 */
4487 if (vp->v_mount == NULL) {
4488 VI_LOCK(vp);
4489 } else {
4490 delmntque(vp);
4491 ASSERT_VI_LOCKED(vp, "vgonel 2");
4492 }
4493 /*
4494 * Done with purge, reset to the standard lock and invalidate
4495 * the vnode.
4496 */
4497 vp->v_vnlock = &vp->v_lock;
4498 vp->v_op = &dead_vnodeops;
4499 vp->v_type = VBAD;
4500 vn_set_state(vp, VSTATE_DEAD);
4501 }
4502
4503 /*
4504 * Print out a description of a vnode.
4505 */
4506 static const char *const vtypename[] = {
4507 [VNON] = "VNON",
4508 [VREG] = "VREG",
4509 [VDIR] = "VDIR",
4510 [VBLK] = "VBLK",
4511 [VCHR] = "VCHR",
4512 [VLNK] = "VLNK",
4513 [VSOCK] = "VSOCK",
4514 [VFIFO] = "VFIFO",
4515 [VBAD] = "VBAD",
4516 [VMARKER] = "VMARKER",
4517 };
4518 _Static_assert(nitems(vtypename) == VLASTTYPE + 1,
4519 "vnode type name not added to vtypename");
4520
4521 static const char *const vstatename[] = {
4522 [VSTATE_UNINITIALIZED] = "VSTATE_UNINITIALIZED",
4523 [VSTATE_CONSTRUCTED] = "VSTATE_CONSTRUCTED",
4524 [VSTATE_DESTROYING] = "VSTATE_DESTROYING",
4525 [VSTATE_DEAD] = "VSTATE_DEAD",
4526 };
4527 _Static_assert(nitems(vstatename) == VLASTSTATE + 1,
4528 "vnode state name not added to vstatename");
4529
4530 _Static_assert((VHOLD_ALL_FLAGS & ~VHOLD_NO_SMR) == 0,
4531 "new hold count flag not added to vn_printf");
4532
4533 void
vn_printf(struct vnode * vp,const char * fmt,...)4534 vn_printf(struct vnode *vp, const char *fmt, ...)
4535 {
4536 va_list ap;
4537 char buf[256], buf2[16];
4538 u_long flags;
4539 u_int holdcnt;
4540 short irflag;
4541
4542 va_start(ap, fmt);
4543 vprintf(fmt, ap);
4544 va_end(ap);
4545 printf("%p: ", (void *)vp);
4546 printf("type %s state %s op %p\n", vtypename[vp->v_type],
4547 vstatename[vp->v_state], vp->v_op);
4548 holdcnt = atomic_load_int(&vp->v_holdcnt);
4549 printf(" usecount %d, writecount %d, refcount %d seqc users %d",
4550 vp->v_usecount, vp->v_writecount, holdcnt & ~VHOLD_ALL_FLAGS,
4551 vp->v_seqc_users);
4552 switch (vp->v_type) {
4553 case VDIR:
4554 printf(" mountedhere %p\n", vp->v_mountedhere);
4555 break;
4556 case VCHR:
4557 printf(" rdev %p\n", vp->v_rdev);
4558 break;
4559 case VSOCK:
4560 printf(" socket %p\n", vp->v_unpcb);
4561 break;
4562 case VFIFO:
4563 printf(" fifoinfo %p\n", vp->v_fifoinfo);
4564 break;
4565 default:
4566 printf("\n");
4567 break;
4568 }
4569 buf[0] = '\0';
4570 buf[1] = '\0';
4571 if (holdcnt & VHOLD_NO_SMR)
4572 strlcat(buf, "|VHOLD_NO_SMR", sizeof(buf));
4573 printf(" hold count flags (%s)\n", buf + 1);
4574
4575 buf[0] = '\0';
4576 buf[1] = '\0';
4577 irflag = vn_irflag_read(vp);
4578 if (irflag & VIRF_DOOMED)
4579 strlcat(buf, "|VIRF_DOOMED", sizeof(buf));
4580 if (irflag & VIRF_PGREAD)
4581 strlcat(buf, "|VIRF_PGREAD", sizeof(buf));
4582 if (irflag & VIRF_MOUNTPOINT)
4583 strlcat(buf, "|VIRF_MOUNTPOINT", sizeof(buf));
4584 if (irflag & VIRF_TEXT_REF)
4585 strlcat(buf, "|VIRF_TEXT_REF", sizeof(buf));
4586 flags = irflag & ~(VIRF_DOOMED | VIRF_PGREAD | VIRF_MOUNTPOINT | VIRF_TEXT_REF);
4587 if (flags != 0) {
4588 snprintf(buf2, sizeof(buf2), "|VIRF(0x%lx)", flags);
4589 strlcat(buf, buf2, sizeof(buf));
4590 }
4591 if (vp->v_vflag & VV_ROOT)
4592 strlcat(buf, "|VV_ROOT", sizeof(buf));
4593 if (vp->v_vflag & VV_ISTTY)
4594 strlcat(buf, "|VV_ISTTY", sizeof(buf));
4595 if (vp->v_vflag & VV_NOSYNC)
4596 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
4597 if (vp->v_vflag & VV_ETERNALDEV)
4598 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
4599 if (vp->v_vflag & VV_CACHEDLABEL)
4600 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
4601 if (vp->v_vflag & VV_VMSIZEVNLOCK)
4602 strlcat(buf, "|VV_VMSIZEVNLOCK", sizeof(buf));
4603 if (vp->v_vflag & VV_COPYONWRITE)
4604 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
4605 if (vp->v_vflag & VV_SYSTEM)
4606 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
4607 if (vp->v_vflag & VV_PROCDEP)
4608 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
4609 if (vp->v_vflag & VV_DELETED)
4610 strlcat(buf, "|VV_DELETED", sizeof(buf));
4611 if (vp->v_vflag & VV_MD)
4612 strlcat(buf, "|VV_MD", sizeof(buf));
4613 if (vp->v_vflag & VV_FORCEINSMQ)
4614 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
4615 if (vp->v_vflag & VV_READLINK)
4616 strlcat(buf, "|VV_READLINK", sizeof(buf));
4617 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
4618 VV_CACHEDLABEL | VV_VMSIZEVNLOCK | VV_COPYONWRITE | VV_SYSTEM |
4619 VV_PROCDEP | VV_DELETED | VV_MD | VV_FORCEINSMQ | VV_READLINK);
4620 if (flags != 0) {
4621 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
4622 strlcat(buf, buf2, sizeof(buf));
4623 }
4624 if (vp->v_iflag & VI_MOUNT)
4625 strlcat(buf, "|VI_MOUNT", sizeof(buf));
4626 if (vp->v_iflag & VI_DOINGINACT)
4627 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
4628 if (vp->v_iflag & VI_OWEINACT)
4629 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
4630 if (vp->v_iflag & VI_DEFINACT)
4631 strlcat(buf, "|VI_DEFINACT", sizeof(buf));
4632 if (vp->v_iflag & VI_FOPENING)
4633 strlcat(buf, "|VI_FOPENING", sizeof(buf));
4634 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOINGINACT |
4635 VI_OWEINACT | VI_DEFINACT | VI_FOPENING);
4636 if (flags != 0) {
4637 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
4638 strlcat(buf, buf2, sizeof(buf));
4639 }
4640 if (vp->v_mflag & VMP_LAZYLIST)
4641 strlcat(buf, "|VMP_LAZYLIST", sizeof(buf));
4642 flags = vp->v_mflag & ~(VMP_LAZYLIST);
4643 if (flags != 0) {
4644 snprintf(buf2, sizeof(buf2), "|VMP(0x%lx)", flags);
4645 strlcat(buf, buf2, sizeof(buf));
4646 }
4647 printf(" flags (%s)", buf + 1);
4648 if (mtx_owned(VI_MTX(vp)))
4649 printf(" VI_LOCKed");
4650 printf("\n");
4651 if (vp->v_object != NULL)
4652 printf(" v_object %p ref %d pages %d "
4653 "cleanbuf %d dirtybuf %d\n",
4654 vp->v_object, vp->v_object->ref_count,
4655 vp->v_object->resident_page_count,
4656 vp->v_bufobj.bo_clean.bv_cnt,
4657 vp->v_bufobj.bo_dirty.bv_cnt);
4658 printf(" ");
4659 lockmgr_printinfo(vp->v_vnlock);
4660 if (vp->v_data != NULL)
4661 VOP_PRINT(vp);
4662 }
4663
4664 #ifdef DDB
4665 /*
4666 * List all of the locked vnodes in the system.
4667 * Called when debugging the kernel.
4668 */
DB_SHOW_COMMAND_FLAGS(lockedvnods,lockedvnodes,DB_CMD_MEMSAFE)4669 DB_SHOW_COMMAND_FLAGS(lockedvnods, lockedvnodes, DB_CMD_MEMSAFE)
4670 {
4671 struct mount *mp;
4672 struct vnode *vp;
4673
4674 /*
4675 * Note: because this is DDB, we can't obey the locking semantics
4676 * for these structures, which means we could catch an inconsistent
4677 * state and dereference a nasty pointer. Not much to be done
4678 * about that.
4679 */
4680 db_printf("Locked vnodes\n");
4681 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4682 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4683 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
4684 vn_printf(vp, "vnode ");
4685 }
4686 }
4687 }
4688
4689 /*
4690 * Show details about the given vnode.
4691 */
DB_SHOW_COMMAND(vnode,db_show_vnode)4692 DB_SHOW_COMMAND(vnode, db_show_vnode)
4693 {
4694 struct vnode *vp;
4695
4696 if (!have_addr)
4697 return;
4698 vp = (struct vnode *)addr;
4699 vn_printf(vp, "vnode ");
4700 }
4701
4702 /*
4703 * Show details about the given mount point.
4704 */
DB_SHOW_COMMAND(mount,db_show_mount)4705 DB_SHOW_COMMAND(mount, db_show_mount)
4706 {
4707 struct mount *mp;
4708 struct vfsopt *opt;
4709 struct statfs *sp;
4710 struct vnode *vp;
4711 char buf[512];
4712 uint64_t mflags;
4713 u_int flags;
4714
4715 if (!have_addr) {
4716 /* No address given, print short info about all mount points. */
4717 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4718 db_printf("%p %s on %s (%s)\n", mp,
4719 mp->mnt_stat.f_mntfromname,
4720 mp->mnt_stat.f_mntonname,
4721 mp->mnt_stat.f_fstypename);
4722 if (db_pager_quit)
4723 break;
4724 }
4725 db_printf("\nMore info: show mount <addr>\n");
4726 return;
4727 }
4728
4729 mp = (struct mount *)addr;
4730 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
4731 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
4732
4733 buf[0] = '\0';
4734 mflags = mp->mnt_flag;
4735 #define MNT_FLAG(flag) do { \
4736 if (mflags & (flag)) { \
4737 if (buf[0] != '\0') \
4738 strlcat(buf, ", ", sizeof(buf)); \
4739 strlcat(buf, (#flag) + 4, sizeof(buf)); \
4740 mflags &= ~(flag); \
4741 } \
4742 } while (0)
4743 MNT_FLAG(MNT_RDONLY);
4744 MNT_FLAG(MNT_SYNCHRONOUS);
4745 MNT_FLAG(MNT_NOEXEC);
4746 MNT_FLAG(MNT_NOSUID);
4747 MNT_FLAG(MNT_NFS4ACLS);
4748 MNT_FLAG(MNT_UNION);
4749 MNT_FLAG(MNT_ASYNC);
4750 MNT_FLAG(MNT_SUIDDIR);
4751 MNT_FLAG(MNT_SOFTDEP);
4752 MNT_FLAG(MNT_NOSYMFOLLOW);
4753 MNT_FLAG(MNT_GJOURNAL);
4754 MNT_FLAG(MNT_MULTILABEL);
4755 MNT_FLAG(MNT_ACLS);
4756 MNT_FLAG(MNT_NOATIME);
4757 MNT_FLAG(MNT_NOCLUSTERR);
4758 MNT_FLAG(MNT_NOCLUSTERW);
4759 MNT_FLAG(MNT_SUJ);
4760 MNT_FLAG(MNT_EXRDONLY);
4761 MNT_FLAG(MNT_EXPORTED);
4762 MNT_FLAG(MNT_DEFEXPORTED);
4763 MNT_FLAG(MNT_EXPORTANON);
4764 MNT_FLAG(MNT_EXKERB);
4765 MNT_FLAG(MNT_EXPUBLIC);
4766 MNT_FLAG(MNT_LOCAL);
4767 MNT_FLAG(MNT_QUOTA);
4768 MNT_FLAG(MNT_ROOTFS);
4769 MNT_FLAG(MNT_USER);
4770 MNT_FLAG(MNT_IGNORE);
4771 MNT_FLAG(MNT_UPDATE);
4772 MNT_FLAG(MNT_DELEXPORT);
4773 MNT_FLAG(MNT_RELOAD);
4774 MNT_FLAG(MNT_FORCE);
4775 MNT_FLAG(MNT_SNAPSHOT);
4776 MNT_FLAG(MNT_BYFSID);
4777 #undef MNT_FLAG
4778 if (mflags != 0) {
4779 if (buf[0] != '\0')
4780 strlcat(buf, ", ", sizeof(buf));
4781 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4782 "0x%016jx", mflags);
4783 }
4784 db_printf(" mnt_flag = %s\n", buf);
4785
4786 buf[0] = '\0';
4787 flags = mp->mnt_kern_flag;
4788 #define MNT_KERN_FLAG(flag) do { \
4789 if (flags & (flag)) { \
4790 if (buf[0] != '\0') \
4791 strlcat(buf, ", ", sizeof(buf)); \
4792 strlcat(buf, (#flag) + 5, sizeof(buf)); \
4793 flags &= ~(flag); \
4794 } \
4795 } while (0)
4796 MNT_KERN_FLAG(MNTK_UNMOUNTF);
4797 MNT_KERN_FLAG(MNTK_ASYNC);
4798 MNT_KERN_FLAG(MNTK_SOFTDEP);
4799 MNT_KERN_FLAG(MNTK_NOMSYNC);
4800 MNT_KERN_FLAG(MNTK_DRAINING);
4801 MNT_KERN_FLAG(MNTK_REFEXPIRE);
4802 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
4803 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
4804 MNT_KERN_FLAG(MNTK_NO_IOPF);
4805 MNT_KERN_FLAG(MNTK_RECURSE);
4806 MNT_KERN_FLAG(MNTK_UPPER_WAITER);
4807 MNT_KERN_FLAG(MNTK_UNLOCKED_INSMNTQUE);
4808 MNT_KERN_FLAG(MNTK_USES_BCACHE);
4809 MNT_KERN_FLAG(MNTK_VMSETSIZE_BUG);
4810 MNT_KERN_FLAG(MNTK_FPLOOKUP);
4811 MNT_KERN_FLAG(MNTK_TASKQUEUE_WAITER);
4812 MNT_KERN_FLAG(MNTK_NOASYNC);
4813 MNT_KERN_FLAG(MNTK_UNMOUNT);
4814 MNT_KERN_FLAG(MNTK_MWAIT);
4815 MNT_KERN_FLAG(MNTK_SUSPEND);
4816 MNT_KERN_FLAG(MNTK_SUSPEND2);
4817 MNT_KERN_FLAG(MNTK_SUSPENDED);
4818 MNT_KERN_FLAG(MNTK_NULL_NOCACHE);
4819 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
4820 #undef MNT_KERN_FLAG
4821 if (flags != 0) {
4822 if (buf[0] != '\0')
4823 strlcat(buf, ", ", sizeof(buf));
4824 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4825 "0x%08x", flags);
4826 }
4827 db_printf(" mnt_kern_flag = %s\n", buf);
4828
4829 db_printf(" mnt_opt = ");
4830 opt = TAILQ_FIRST(mp->mnt_opt);
4831 if (opt != NULL) {
4832 db_printf("%s", opt->name);
4833 opt = TAILQ_NEXT(opt, link);
4834 while (opt != NULL) {
4835 db_printf(", %s", opt->name);
4836 opt = TAILQ_NEXT(opt, link);
4837 }
4838 }
4839 db_printf("\n");
4840
4841 sp = &mp->mnt_stat;
4842 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
4843 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
4844 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
4845 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
4846 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
4847 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
4848 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
4849 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
4850 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
4851 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
4852 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
4853 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
4854
4855 db_printf(" mnt_cred = { uid=%u ruid=%u",
4856 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
4857 if (jailed(mp->mnt_cred))
4858 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
4859 db_printf(" }\n");
4860 db_printf(" mnt_ref = %d (with %d in the struct)\n",
4861 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref);
4862 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
4863 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
4864 db_printf(" mnt_lazyvnodelistsize = %d\n",
4865 mp->mnt_lazyvnodelistsize);
4866 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n",
4867 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount);
4868 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
4869 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
4870 db_printf(" mnt_lockref = %d (with %d in the struct)\n",
4871 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref);
4872 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
4873 db_printf(" mnt_secondary_accwrites = %d\n",
4874 mp->mnt_secondary_accwrites);
4875 db_printf(" mnt_gjprovider = %s\n",
4876 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
4877 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops);
4878
4879 db_printf("\n\nList of active vnodes\n");
4880 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4881 if (vp->v_type != VMARKER && vp->v_holdcnt > 0) {
4882 vn_printf(vp, "vnode ");
4883 if (db_pager_quit)
4884 break;
4885 }
4886 }
4887 db_printf("\n\nList of inactive vnodes\n");
4888 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4889 if (vp->v_type != VMARKER && vp->v_holdcnt == 0) {
4890 vn_printf(vp, "vnode ");
4891 if (db_pager_quit)
4892 break;
4893 }
4894 }
4895 }
4896 #endif /* DDB */
4897
4898 /*
4899 * Fill in a struct xvfsconf based on a struct vfsconf.
4900 */
4901 static int
vfsconf2x(struct sysctl_req * req,struct vfsconf * vfsp)4902 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
4903 {
4904 struct xvfsconf xvfsp;
4905
4906 bzero(&xvfsp, sizeof(xvfsp));
4907 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4908 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4909 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4910 xvfsp.vfc_flags = vfsp->vfc_flags;
4911 /*
4912 * These are unused in userland, we keep them
4913 * to not break binary compatibility.
4914 */
4915 xvfsp.vfc_vfsops = NULL;
4916 xvfsp.vfc_next = NULL;
4917 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4918 }
4919
4920 #ifdef COMPAT_FREEBSD32
4921 struct xvfsconf32 {
4922 uint32_t vfc_vfsops;
4923 char vfc_name[MFSNAMELEN];
4924 int32_t vfc_typenum;
4925 int32_t vfc_refcount;
4926 int32_t vfc_flags;
4927 uint32_t vfc_next;
4928 };
4929
4930 static int
vfsconf2x32(struct sysctl_req * req,struct vfsconf * vfsp)4931 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
4932 {
4933 struct xvfsconf32 xvfsp;
4934
4935 bzero(&xvfsp, sizeof(xvfsp));
4936 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4937 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4938 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4939 xvfsp.vfc_flags = vfsp->vfc_flags;
4940 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4941 }
4942 #endif
4943
4944 /*
4945 * Top level filesystem related information gathering.
4946 */
4947 static int
sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)4948 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
4949 {
4950 struct vfsconf *vfsp;
4951 int error;
4952
4953 error = 0;
4954 vfsconf_slock();
4955 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4956 #ifdef COMPAT_FREEBSD32
4957 if (req->flags & SCTL_MASK32)
4958 error = vfsconf2x32(req, vfsp);
4959 else
4960 #endif
4961 error = vfsconf2x(req, vfsp);
4962 if (error)
4963 break;
4964 }
4965 vfsconf_sunlock();
4966 return (error);
4967 }
4968
4969 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
4970 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
4971 "S,xvfsconf", "List of all configured filesystems");
4972
4973 #ifndef BURN_BRIDGES
4974 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
4975
4976 static int
vfs_sysctl(SYSCTL_HANDLER_ARGS)4977 vfs_sysctl(SYSCTL_HANDLER_ARGS)
4978 {
4979 int *name = (int *)arg1 - 1; /* XXX */
4980 u_int namelen = arg2 + 1; /* XXX */
4981 struct vfsconf *vfsp;
4982
4983 log(LOG_WARNING, "userland calling deprecated sysctl, "
4984 "please rebuild world\n");
4985
4986 #if 1 || defined(COMPAT_PRELITE2)
4987 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
4988 if (namelen == 1)
4989 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
4990 #endif
4991
4992 switch (name[1]) {
4993 case VFS_MAXTYPENUM:
4994 if (namelen != 2)
4995 return (ENOTDIR);
4996 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
4997 case VFS_CONF:
4998 if (namelen != 3)
4999 return (ENOTDIR); /* overloaded */
5000 vfsconf_slock();
5001 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
5002 if (vfsp->vfc_typenum == name[2])
5003 break;
5004 }
5005 vfsconf_sunlock();
5006 if (vfsp == NULL)
5007 return (EOPNOTSUPP);
5008 #ifdef COMPAT_FREEBSD32
5009 if (req->flags & SCTL_MASK32)
5010 return (vfsconf2x32(req, vfsp));
5011 else
5012 #endif
5013 return (vfsconf2x(req, vfsp));
5014 }
5015 return (EOPNOTSUPP);
5016 }
5017
5018 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
5019 CTLFLAG_MPSAFE, vfs_sysctl,
5020 "Generic filesystem");
5021
5022 #if 1 || defined(COMPAT_PRELITE2)
5023
5024 static int
sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)5025 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
5026 {
5027 int error;
5028 struct vfsconf *vfsp;
5029 struct ovfsconf ovfs;
5030
5031 vfsconf_slock();
5032 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
5033 bzero(&ovfs, sizeof(ovfs));
5034 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
5035 strcpy(ovfs.vfc_name, vfsp->vfc_name);
5036 ovfs.vfc_index = vfsp->vfc_typenum;
5037 ovfs.vfc_refcount = vfsp->vfc_refcount;
5038 ovfs.vfc_flags = vfsp->vfc_flags;
5039 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
5040 if (error != 0) {
5041 vfsconf_sunlock();
5042 return (error);
5043 }
5044 }
5045 vfsconf_sunlock();
5046 return (0);
5047 }
5048
5049 #endif /* 1 || COMPAT_PRELITE2 */
5050 #endif /* !BURN_BRIDGES */
5051
5052 static void
unmount_or_warn(struct mount * mp)5053 unmount_or_warn(struct mount *mp)
5054 {
5055 int error;
5056
5057 error = dounmount(mp, MNT_FORCE, curthread);
5058 if (error != 0) {
5059 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
5060 if (error == EBUSY)
5061 printf("BUSY)\n");
5062 else
5063 printf("%d)\n", error);
5064 }
5065 }
5066
5067 /*
5068 * Unmount all filesystems. The list is traversed in reverse order
5069 * of mounting to avoid dependencies.
5070 */
5071 void
vfs_unmountall(void)5072 vfs_unmountall(void)
5073 {
5074 struct mount *mp, *tmp;
5075
5076 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
5077
5078 /*
5079 * Since this only runs when rebooting, it is not interlocked.
5080 */
5081 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
5082 vfs_ref(mp);
5083
5084 /*
5085 * Forcibly unmounting "/dev" before "/" would prevent clean
5086 * unmount of the latter.
5087 */
5088 if (mp == rootdevmp)
5089 continue;
5090
5091 unmount_or_warn(mp);
5092 }
5093
5094 if (rootdevmp != NULL)
5095 unmount_or_warn(rootdevmp);
5096 }
5097
5098 static void
vfs_deferred_inactive(struct vnode * vp,int lkflags)5099 vfs_deferred_inactive(struct vnode *vp, int lkflags)
5100 {
5101
5102 ASSERT_VI_LOCKED(vp, __func__);
5103 VNPASS((vp->v_iflag & VI_DEFINACT) == 0, vp);
5104 if ((vp->v_iflag & VI_OWEINACT) == 0) {
5105 vdropl(vp);
5106 return;
5107 }
5108 if (vn_lock(vp, lkflags) == 0) {
5109 VI_LOCK(vp);
5110 vinactive(vp);
5111 VOP_UNLOCK(vp);
5112 vdropl(vp);
5113 return;
5114 }
5115 vdefer_inactive_unlocked(vp);
5116 }
5117
5118 static int
vfs_periodic_inactive_filter(struct vnode * vp,void * arg)5119 vfs_periodic_inactive_filter(struct vnode *vp, void *arg)
5120 {
5121
5122 return (vp->v_iflag & VI_DEFINACT);
5123 }
5124
5125 static void __noinline
vfs_periodic_inactive(struct mount * mp,int flags)5126 vfs_periodic_inactive(struct mount *mp, int flags)
5127 {
5128 struct vnode *vp, *mvp;
5129 int lkflags;
5130
5131 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5132 if (flags != MNT_WAIT)
5133 lkflags |= LK_NOWAIT;
5134
5135 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_inactive_filter, NULL) {
5136 if ((vp->v_iflag & VI_DEFINACT) == 0) {
5137 VI_UNLOCK(vp);
5138 continue;
5139 }
5140 vp->v_iflag &= ~VI_DEFINACT;
5141 vfs_deferred_inactive(vp, lkflags);
5142 }
5143 }
5144
5145 static inline bool
vfs_want_msync(struct vnode * vp)5146 vfs_want_msync(struct vnode *vp)
5147 {
5148 struct vm_object *obj;
5149
5150 /*
5151 * This test may be performed without any locks held.
5152 * We rely on vm_object's type stability.
5153 */
5154 if (vp->v_vflag & VV_NOSYNC)
5155 return (false);
5156 obj = vp->v_object;
5157 return (obj != NULL && vm_object_mightbedirty(obj));
5158 }
5159
5160 static int
vfs_periodic_msync_inactive_filter(struct vnode * vp,void * arg __unused)5161 vfs_periodic_msync_inactive_filter(struct vnode *vp, void *arg __unused)
5162 {
5163
5164 if (vp->v_vflag & VV_NOSYNC)
5165 return (false);
5166 if (vp->v_iflag & VI_DEFINACT)
5167 return (true);
5168 return (vfs_want_msync(vp));
5169 }
5170
5171 static void __noinline
vfs_periodic_msync_inactive(struct mount * mp,int flags)5172 vfs_periodic_msync_inactive(struct mount *mp, int flags)
5173 {
5174 struct vnode *vp, *mvp;
5175 int lkflags;
5176 bool seen_defer;
5177
5178 lkflags = LK_EXCLUSIVE | LK_INTERLOCK;
5179 if (flags != MNT_WAIT)
5180 lkflags |= LK_NOWAIT;
5181
5182 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, vfs_periodic_msync_inactive_filter, NULL) {
5183 seen_defer = false;
5184 if (vp->v_iflag & VI_DEFINACT) {
5185 vp->v_iflag &= ~VI_DEFINACT;
5186 seen_defer = true;
5187 }
5188 if (!vfs_want_msync(vp)) {
5189 if (seen_defer)
5190 vfs_deferred_inactive(vp, lkflags);
5191 else
5192 VI_UNLOCK(vp);
5193 continue;
5194 }
5195 if (vget(vp, lkflags) == 0) {
5196 if ((vp->v_vflag & VV_NOSYNC) == 0) {
5197 if (flags == MNT_WAIT)
5198 vnode_pager_clean_sync(vp);
5199 else
5200 vnode_pager_clean_async(vp);
5201 }
5202 vput(vp);
5203 if (seen_defer)
5204 vdrop(vp);
5205 } else {
5206 if (seen_defer)
5207 vdefer_inactive_unlocked(vp);
5208 }
5209 }
5210 }
5211
5212 void
vfs_periodic(struct mount * mp,int flags)5213 vfs_periodic(struct mount *mp, int flags)
5214 {
5215
5216 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
5217
5218 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0)
5219 vfs_periodic_inactive(mp, flags);
5220 else
5221 vfs_periodic_msync_inactive(mp, flags);
5222 }
5223
5224 static void
destroy_vpollinfo_free(struct vpollinfo * vi)5225 destroy_vpollinfo_free(struct vpollinfo *vi)
5226 {
5227
5228 knlist_destroy(&vi->vpi_selinfo.si_note);
5229 mtx_destroy(&vi->vpi_lock);
5230 free(vi, M_VNODEPOLL);
5231 }
5232
5233 static void
destroy_vpollinfo(struct vpollinfo * vi)5234 destroy_vpollinfo(struct vpollinfo *vi)
5235 {
5236
5237 knlist_clear(&vi->vpi_selinfo.si_note, 1);
5238 seldrain(&vi->vpi_selinfo);
5239 destroy_vpollinfo_free(vi);
5240 }
5241
5242 /*
5243 * Initialize per-vnode helper structure to hold poll-related state.
5244 */
5245 void
v_addpollinfo(struct vnode * vp)5246 v_addpollinfo(struct vnode *vp)
5247 {
5248 struct vpollinfo *vi;
5249
5250 if (vp->v_pollinfo != NULL)
5251 return;
5252 vi = malloc(sizeof(*vi), M_VNODEPOLL, M_WAITOK | M_ZERO);
5253 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
5254 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
5255 vfs_knlunlock, vfs_knl_assert_lock);
5256 VI_LOCK(vp);
5257 if (vp->v_pollinfo != NULL) {
5258 VI_UNLOCK(vp);
5259 destroy_vpollinfo_free(vi);
5260 return;
5261 }
5262 vp->v_pollinfo = vi;
5263 VI_UNLOCK(vp);
5264 }
5265
5266 /*
5267 * Record a process's interest in events which might happen to
5268 * a vnode. Because poll uses the historic select-style interface
5269 * internally, this routine serves as both the ``check for any
5270 * pending events'' and the ``record my interest in future events''
5271 * functions. (These are done together, while the lock is held,
5272 * to avoid race conditions.)
5273 */
5274 int
vn_pollrecord(struct vnode * vp,struct thread * td,int events)5275 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
5276 {
5277
5278 v_addpollinfo(vp);
5279 mtx_lock(&vp->v_pollinfo->vpi_lock);
5280 if (vp->v_pollinfo->vpi_revents & events) {
5281 /*
5282 * This leaves events we are not interested
5283 * in available for the other process which
5284 * which presumably had requested them
5285 * (otherwise they would never have been
5286 * recorded).
5287 */
5288 events &= vp->v_pollinfo->vpi_revents;
5289 vp->v_pollinfo->vpi_revents &= ~events;
5290
5291 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5292 return (events);
5293 }
5294 vp->v_pollinfo->vpi_events |= events;
5295 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
5296 mtx_unlock(&vp->v_pollinfo->vpi_lock);
5297 return (0);
5298 }
5299
5300 /*
5301 * Routine to create and manage a filesystem syncer vnode.
5302 */
5303 #define sync_close ((int (*)(struct vop_close_args *))nullop)
5304 static int sync_fsync(struct vop_fsync_args *);
5305 static int sync_inactive(struct vop_inactive_args *);
5306 static int sync_reclaim(struct vop_reclaim_args *);
5307
5308 static struct vop_vector sync_vnodeops = {
5309 .vop_bypass = VOP_EOPNOTSUPP,
5310 .vop_close = sync_close,
5311 .vop_fsync = sync_fsync,
5312 .vop_getwritemount = vop_stdgetwritemount,
5313 .vop_inactive = sync_inactive,
5314 .vop_need_inactive = vop_stdneed_inactive,
5315 .vop_reclaim = sync_reclaim,
5316 .vop_lock1 = vop_stdlock,
5317 .vop_unlock = vop_stdunlock,
5318 .vop_islocked = vop_stdislocked,
5319 .vop_fplookup_vexec = VOP_EAGAIN,
5320 .vop_fplookup_symlink = VOP_EAGAIN,
5321 };
5322 VFS_VOP_VECTOR_REGISTER(sync_vnodeops);
5323
5324 /*
5325 * Create a new filesystem syncer vnode for the specified mount point.
5326 */
5327 void
vfs_allocate_syncvnode(struct mount * mp)5328 vfs_allocate_syncvnode(struct mount *mp)
5329 {
5330 struct vnode *vp;
5331 struct bufobj *bo;
5332 static long start, incr, next;
5333 int error;
5334
5335 /* Allocate a new vnode */
5336 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
5337 if (error != 0)
5338 panic("vfs_allocate_syncvnode: getnewvnode() failed");
5339 vp->v_type = VNON;
5340 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5341 vp->v_vflag |= VV_FORCEINSMQ;
5342 error = insmntque1(vp, mp);
5343 if (error != 0)
5344 panic("vfs_allocate_syncvnode: insmntque() failed");
5345 vp->v_vflag &= ~VV_FORCEINSMQ;
5346 vn_set_state(vp, VSTATE_CONSTRUCTED);
5347 VOP_UNLOCK(vp);
5348 /*
5349 * Place the vnode onto the syncer worklist. We attempt to
5350 * scatter them about on the list so that they will go off
5351 * at evenly distributed times even if all the filesystems
5352 * are mounted at once.
5353 */
5354 next += incr;
5355 if (next == 0 || next > syncer_maxdelay) {
5356 start /= 2;
5357 incr /= 2;
5358 if (start == 0) {
5359 start = syncer_maxdelay / 2;
5360 incr = syncer_maxdelay;
5361 }
5362 next = start;
5363 }
5364 bo = &vp->v_bufobj;
5365 BO_LOCK(bo);
5366 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
5367 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
5368 mtx_lock(&sync_mtx);
5369 sync_vnode_count++;
5370 if (mp->mnt_syncer == NULL) {
5371 mp->mnt_syncer = vp;
5372 vp = NULL;
5373 }
5374 mtx_unlock(&sync_mtx);
5375 BO_UNLOCK(bo);
5376 if (vp != NULL) {
5377 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5378 vgone(vp);
5379 vput(vp);
5380 }
5381 }
5382
5383 void
vfs_deallocate_syncvnode(struct mount * mp)5384 vfs_deallocate_syncvnode(struct mount *mp)
5385 {
5386 struct vnode *vp;
5387
5388 mtx_lock(&sync_mtx);
5389 vp = mp->mnt_syncer;
5390 if (vp != NULL)
5391 mp->mnt_syncer = NULL;
5392 mtx_unlock(&sync_mtx);
5393 if (vp != NULL)
5394 vrele(vp);
5395 }
5396
5397 /*
5398 * Do a lazy sync of the filesystem.
5399 */
5400 static int
sync_fsync(struct vop_fsync_args * ap)5401 sync_fsync(struct vop_fsync_args *ap)
5402 {
5403 struct vnode *syncvp = ap->a_vp;
5404 struct mount *mp = syncvp->v_mount;
5405 int error, save;
5406 struct bufobj *bo;
5407
5408 /*
5409 * We only need to do something if this is a lazy evaluation.
5410 */
5411 if (ap->a_waitfor != MNT_LAZY)
5412 return (0);
5413
5414 /*
5415 * Move ourselves to the back of the sync list.
5416 */
5417 bo = &syncvp->v_bufobj;
5418 BO_LOCK(bo);
5419 vn_syncer_add_to_worklist(bo, syncdelay);
5420 BO_UNLOCK(bo);
5421
5422 /*
5423 * Walk the list of vnodes pushing all that are dirty and
5424 * not already on the sync list.
5425 */
5426 if (vfs_busy(mp, MBF_NOWAIT) != 0)
5427 return (0);
5428 VOP_UNLOCK(syncvp);
5429 save = curthread_pflags_set(TDP_SYNCIO);
5430 /*
5431 * The filesystem at hand may be idle with free vnodes stored in the
5432 * batch. Return them instead of letting them stay there indefinitely.
5433 */
5434 vfs_periodic(mp, MNT_NOWAIT);
5435 error = VFS_SYNC(mp, MNT_LAZY);
5436 curthread_pflags_restore(save);
5437 vn_lock(syncvp, LK_EXCLUSIVE | LK_RETRY);
5438 vfs_unbusy(mp);
5439 return (error);
5440 }
5441
5442 /*
5443 * The syncer vnode is no referenced.
5444 */
5445 static int
sync_inactive(struct vop_inactive_args * ap)5446 sync_inactive(struct vop_inactive_args *ap)
5447 {
5448
5449 vgone(ap->a_vp);
5450 return (0);
5451 }
5452
5453 /*
5454 * The syncer vnode is no longer needed and is being decommissioned.
5455 *
5456 * Modifications to the worklist must be protected by sync_mtx.
5457 */
5458 static int
sync_reclaim(struct vop_reclaim_args * ap)5459 sync_reclaim(struct vop_reclaim_args *ap)
5460 {
5461 struct vnode *vp = ap->a_vp;
5462 struct bufobj *bo;
5463
5464 bo = &vp->v_bufobj;
5465 BO_LOCK(bo);
5466 mtx_lock(&sync_mtx);
5467 if (vp->v_mount->mnt_syncer == vp)
5468 vp->v_mount->mnt_syncer = NULL;
5469 if (bo->bo_flag & BO_ONWORKLST) {
5470 LIST_REMOVE(bo, bo_synclist);
5471 syncer_worklist_len--;
5472 sync_vnode_count--;
5473 bo->bo_flag &= ~BO_ONWORKLST;
5474 }
5475 mtx_unlock(&sync_mtx);
5476 BO_UNLOCK(bo);
5477
5478 return (0);
5479 }
5480
5481 int
vn_need_pageq_flush(struct vnode * vp)5482 vn_need_pageq_flush(struct vnode *vp)
5483 {
5484 struct vm_object *obj;
5485
5486 obj = vp->v_object;
5487 return (obj != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
5488 vm_object_mightbedirty(obj));
5489 }
5490
5491 /*
5492 * Check if vnode represents a disk device
5493 */
5494 bool
vn_isdisk_error(struct vnode * vp,int * errp)5495 vn_isdisk_error(struct vnode *vp, int *errp)
5496 {
5497 int error;
5498
5499 if (vp->v_type != VCHR) {
5500 error = ENOTBLK;
5501 goto out;
5502 }
5503 error = 0;
5504 dev_lock();
5505 if (vp->v_rdev == NULL)
5506 error = ENXIO;
5507 else if (vp->v_rdev->si_devsw == NULL)
5508 error = ENXIO;
5509 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
5510 error = ENOTBLK;
5511 dev_unlock();
5512 out:
5513 *errp = error;
5514 return (error == 0);
5515 }
5516
5517 bool
vn_isdisk(struct vnode * vp)5518 vn_isdisk(struct vnode *vp)
5519 {
5520 int error;
5521
5522 return (vn_isdisk_error(vp, &error));
5523 }
5524
5525 /*
5526 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see
5527 * the comment above cache_fplookup for details.
5528 */
5529 int
vaccess_vexec_smr(mode_t file_mode,uid_t file_uid,gid_t file_gid,struct ucred * cred)5530 vaccess_vexec_smr(mode_t file_mode, uid_t file_uid, gid_t file_gid, struct ucred *cred)
5531 {
5532 int error;
5533
5534 VFS_SMR_ASSERT_ENTERED();
5535
5536 /* Check the owner. */
5537 if (cred->cr_uid == file_uid) {
5538 if (file_mode & S_IXUSR)
5539 return (0);
5540 goto out_error;
5541 }
5542
5543 /* Otherwise, check the groups (first match) */
5544 if (groupmember(file_gid, cred)) {
5545 if (file_mode & S_IXGRP)
5546 return (0);
5547 goto out_error;
5548 }
5549
5550 /* Otherwise, check everyone else. */
5551 if (file_mode & S_IXOTH)
5552 return (0);
5553 out_error:
5554 /*
5555 * Permission check failed, but it is possible denial will get overwritten
5556 * (e.g., when root is traversing through a 700 directory owned by someone
5557 * else).
5558 *
5559 * vaccess() calls priv_check_cred which in turn can descent into MAC
5560 * modules overriding this result. It's quite unclear what semantics
5561 * are allowed for them to operate, thus for safety we don't call them
5562 * from within the SMR section. This also means if any such modules
5563 * are present, we have to let the regular lookup decide.
5564 */
5565 error = priv_check_cred_vfs_lookup_nomac(cred);
5566 switch (error) {
5567 case 0:
5568 return (0);
5569 case EAGAIN:
5570 /*
5571 * MAC modules present.
5572 */
5573 return (EAGAIN);
5574 case EPERM:
5575 return (EACCES);
5576 default:
5577 return (error);
5578 }
5579 }
5580
5581 /*
5582 * Common filesystem object access control check routine. Accepts a
5583 * vnode's type, "mode", uid and gid, requested access mode, and credentials.
5584 * Returns 0 on success, or an errno on failure.
5585 */
5586 int
vaccess(__enum_uint8 (vtype)type,mode_t file_mode,uid_t file_uid,gid_t file_gid,accmode_t accmode,struct ucred * cred)5587 vaccess(__enum_uint8(vtype) type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
5588 accmode_t accmode, struct ucred *cred)
5589 {
5590 accmode_t dac_granted;
5591 accmode_t priv_granted;
5592
5593 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
5594 ("invalid bit in accmode"));
5595 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
5596 ("VAPPEND without VWRITE"));
5597
5598 /*
5599 * Look for a normal, non-privileged way to access the file/directory
5600 * as requested. If it exists, go with that.
5601 */
5602
5603 dac_granted = 0;
5604
5605 /* Check the owner. */
5606 if (cred->cr_uid == file_uid) {
5607 dac_granted |= VADMIN;
5608 if (file_mode & S_IXUSR)
5609 dac_granted |= VEXEC;
5610 if (file_mode & S_IRUSR)
5611 dac_granted |= VREAD;
5612 if (file_mode & S_IWUSR)
5613 dac_granted |= (VWRITE | VAPPEND);
5614
5615 if ((accmode & dac_granted) == accmode)
5616 return (0);
5617
5618 goto privcheck;
5619 }
5620
5621 /* Otherwise, check the groups (first match) */
5622 if (groupmember(file_gid, cred)) {
5623 if (file_mode & S_IXGRP)
5624 dac_granted |= VEXEC;
5625 if (file_mode & S_IRGRP)
5626 dac_granted |= VREAD;
5627 if (file_mode & S_IWGRP)
5628 dac_granted |= (VWRITE | VAPPEND);
5629
5630 if ((accmode & dac_granted) == accmode)
5631 return (0);
5632
5633 goto privcheck;
5634 }
5635
5636 /* Otherwise, check everyone else. */
5637 if (file_mode & S_IXOTH)
5638 dac_granted |= VEXEC;
5639 if (file_mode & S_IROTH)
5640 dac_granted |= VREAD;
5641 if (file_mode & S_IWOTH)
5642 dac_granted |= (VWRITE | VAPPEND);
5643 if ((accmode & dac_granted) == accmode)
5644 return (0);
5645
5646 privcheck:
5647 /*
5648 * Build a privilege mask to determine if the set of privileges
5649 * satisfies the requirements when combined with the granted mask
5650 * from above. For each privilege, if the privilege is required,
5651 * bitwise or the request type onto the priv_granted mask.
5652 */
5653 priv_granted = 0;
5654
5655 if (type == VDIR) {
5656 /*
5657 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
5658 * requests, instead of PRIV_VFS_EXEC.
5659 */
5660 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5661 !priv_check_cred(cred, PRIV_VFS_LOOKUP))
5662 priv_granted |= VEXEC;
5663 } else {
5664 /*
5665 * Ensure that at least one execute bit is on. Otherwise,
5666 * a privileged user will always succeed, and we don't want
5667 * this to happen unless the file really is executable.
5668 */
5669 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
5670 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
5671 !priv_check_cred(cred, PRIV_VFS_EXEC))
5672 priv_granted |= VEXEC;
5673 }
5674
5675 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
5676 !priv_check_cred(cred, PRIV_VFS_READ))
5677 priv_granted |= VREAD;
5678
5679 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
5680 !priv_check_cred(cred, PRIV_VFS_WRITE))
5681 priv_granted |= (VWRITE | VAPPEND);
5682
5683 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
5684 !priv_check_cred(cred, PRIV_VFS_ADMIN))
5685 priv_granted |= VADMIN;
5686
5687 if ((accmode & (priv_granted | dac_granted)) == accmode) {
5688 return (0);
5689 }
5690
5691 return ((accmode & VADMIN) ? EPERM : EACCES);
5692 }
5693
5694 /*
5695 * Credential check based on process requesting service, and per-attribute
5696 * permissions.
5697 */
5698 int
extattr_check_cred(struct vnode * vp,int attrnamespace,struct ucred * cred,struct thread * td,accmode_t accmode)5699 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
5700 struct thread *td, accmode_t accmode)
5701 {
5702
5703 /*
5704 * Kernel-invoked always succeeds.
5705 */
5706 if (cred == NOCRED)
5707 return (0);
5708
5709 /*
5710 * Do not allow privileged processes in jail to directly manipulate
5711 * system attributes.
5712 */
5713 switch (attrnamespace) {
5714 case EXTATTR_NAMESPACE_SYSTEM:
5715 /* Potentially should be: return (EPERM); */
5716 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM));
5717 case EXTATTR_NAMESPACE_USER:
5718 return (VOP_ACCESS(vp, accmode, cred, td));
5719 default:
5720 return (EPERM);
5721 }
5722 }
5723
5724 #ifdef DEBUG_VFS_LOCKS
5725 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
5726 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
5727 "Drop into debugger on lock violation");
5728
5729 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
5730 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
5731 0, "Check for interlock across VOPs");
5732
5733 int vfs_badlock_print = 1; /* Print lock violations. */
5734 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
5735 0, "Print lock violations");
5736
5737 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
5738 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
5739 0, "Print vnode details on lock violations");
5740
5741 #ifdef KDB
5742 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
5743 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
5744 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
5745 #endif
5746
5747 static void
vfs_badlock(const char * msg,const char * str,struct vnode * vp)5748 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
5749 {
5750
5751 #ifdef KDB
5752 if (vfs_badlock_backtrace)
5753 kdb_backtrace();
5754 #endif
5755 if (vfs_badlock_vnode)
5756 vn_printf(vp, "vnode ");
5757 if (vfs_badlock_print)
5758 printf("%s: %p %s\n", str, (void *)vp, msg);
5759 if (vfs_badlock_ddb)
5760 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5761 }
5762
5763 void
assert_vi_locked(struct vnode * vp,const char * str)5764 assert_vi_locked(struct vnode *vp, const char *str)
5765 {
5766
5767 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
5768 vfs_badlock("interlock is not locked but should be", str, vp);
5769 }
5770
5771 void
assert_vi_unlocked(struct vnode * vp,const char * str)5772 assert_vi_unlocked(struct vnode *vp, const char *str)
5773 {
5774
5775 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
5776 vfs_badlock("interlock is locked but should not be", str, vp);
5777 }
5778
5779 void
assert_vop_locked(struct vnode * vp,const char * str)5780 assert_vop_locked(struct vnode *vp, const char *str)
5781 {
5782 if (KERNEL_PANICKED() || vp == NULL)
5783 return;
5784
5785 #ifdef WITNESS
5786 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5787 witness_is_owned(&vp->v_vnlock->lock_object) == -1)
5788 #else
5789 int locked = VOP_ISLOCKED(vp);
5790 if (locked == 0 || locked == LK_EXCLOTHER)
5791 #endif
5792 vfs_badlock("is not locked but should be", str, vp);
5793 }
5794
5795 void
assert_vop_unlocked(struct vnode * vp,const char * str)5796 assert_vop_unlocked(struct vnode *vp, const char *str)
5797 {
5798 if (KERNEL_PANICKED() || vp == NULL)
5799 return;
5800
5801 #ifdef WITNESS
5802 if ((vp->v_irflag & VIRF_CROSSMP) == 0 &&
5803 witness_is_owned(&vp->v_vnlock->lock_object) == 1)
5804 #else
5805 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
5806 #endif
5807 vfs_badlock("is locked but should not be", str, vp);
5808 }
5809
5810 void
assert_vop_elocked(struct vnode * vp,const char * str)5811 assert_vop_elocked(struct vnode *vp, const char *str)
5812 {
5813 if (KERNEL_PANICKED() || vp == NULL)
5814 return;
5815
5816 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
5817 vfs_badlock("is not exclusive locked but should be", str, vp);
5818 }
5819 #endif /* DEBUG_VFS_LOCKS */
5820
5821 void
vop_rename_fail(struct vop_rename_args * ap)5822 vop_rename_fail(struct vop_rename_args *ap)
5823 {
5824
5825 if (ap->a_tvp != NULL)
5826 vput(ap->a_tvp);
5827 if (ap->a_tdvp == ap->a_tvp)
5828 vrele(ap->a_tdvp);
5829 else
5830 vput(ap->a_tdvp);
5831 vrele(ap->a_fdvp);
5832 vrele(ap->a_fvp);
5833 }
5834
5835 void
vop_rename_pre(void * ap)5836 vop_rename_pre(void *ap)
5837 {
5838 struct vop_rename_args *a = ap;
5839
5840 #ifdef DEBUG_VFS_LOCKS
5841 if (a->a_tvp)
5842 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
5843 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
5844 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
5845 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
5846
5847 /* Check the source (from). */
5848 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
5849 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
5850 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
5851 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
5852 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
5853
5854 /* Check the target. */
5855 if (a->a_tvp)
5856 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
5857 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
5858 #endif
5859 /*
5860 * It may be tempting to add vn_seqc_write_begin/end calls here and
5861 * in vop_rename_post but that's not going to work out since some
5862 * filesystems relookup vnodes mid-rename. This is probably a bug.
5863 *
5864 * For now filesystems are expected to do the relevant calls after they
5865 * decide what vnodes to operate on.
5866 */
5867 if (a->a_tdvp != a->a_fdvp)
5868 vhold(a->a_fdvp);
5869 if (a->a_tvp != a->a_fvp)
5870 vhold(a->a_fvp);
5871 vhold(a->a_tdvp);
5872 if (a->a_tvp)
5873 vhold(a->a_tvp);
5874 }
5875
5876 #ifdef DEBUG_VFS_LOCKS
5877 void
vop_fplookup_vexec_debugpre(void * ap __unused)5878 vop_fplookup_vexec_debugpre(void *ap __unused)
5879 {
5880
5881 VFS_SMR_ASSERT_ENTERED();
5882 }
5883
5884 void
vop_fplookup_vexec_debugpost(void * ap,int rc)5885 vop_fplookup_vexec_debugpost(void *ap, int rc)
5886 {
5887 struct vop_fplookup_vexec_args *a;
5888 struct vnode *vp;
5889
5890 a = ap;
5891 vp = a->a_vp;
5892
5893 VFS_SMR_ASSERT_ENTERED();
5894 if (rc == EOPNOTSUPP)
5895 VNPASS(VN_IS_DOOMED(vp), vp);
5896 }
5897
5898 void
vop_fplookup_symlink_debugpre(void * ap __unused)5899 vop_fplookup_symlink_debugpre(void *ap __unused)
5900 {
5901
5902 VFS_SMR_ASSERT_ENTERED();
5903 }
5904
5905 void
vop_fplookup_symlink_debugpost(void * ap __unused,int rc __unused)5906 vop_fplookup_symlink_debugpost(void *ap __unused, int rc __unused)
5907 {
5908
5909 VFS_SMR_ASSERT_ENTERED();
5910 }
5911
5912 static void
vop_fsync_debugprepost(struct vnode * vp,const char * name)5913 vop_fsync_debugprepost(struct vnode *vp, const char *name)
5914 {
5915 if (vp->v_type == VCHR)
5916 ;
5917 /*
5918 * The shared vs. exclusive locking policy for fsync()
5919 * is actually determined by vp's write mount as indicated
5920 * by VOP_GETWRITEMOUNT(), which for stacked filesystems
5921 * may not be the same as vp->v_mount. However, if the
5922 * underlying filesystem which really handles the fsync()
5923 * supports shared locking, the stacked filesystem must also
5924 * be prepared for its VOP_FSYNC() operation to be called
5925 * with only a shared lock. On the other hand, if the
5926 * stacked filesystem claims support for shared write
5927 * locking but the underlying filesystem does not, and the
5928 * caller incorrectly uses a shared lock, this condition
5929 * should still be caught when the stacked filesystem
5930 * invokes VOP_FSYNC() on the underlying filesystem.
5931 */
5932 else if (MNT_SHARED_WRITES(vp->v_mount))
5933 ASSERT_VOP_LOCKED(vp, name);
5934 else
5935 ASSERT_VOP_ELOCKED(vp, name);
5936 }
5937
5938 void
vop_fsync_debugpre(void * a)5939 vop_fsync_debugpre(void *a)
5940 {
5941 struct vop_fsync_args *ap;
5942
5943 ap = a;
5944 vop_fsync_debugprepost(ap->a_vp, "fsync");
5945 }
5946
5947 void
vop_fsync_debugpost(void * a,int rc __unused)5948 vop_fsync_debugpost(void *a, int rc __unused)
5949 {
5950 struct vop_fsync_args *ap;
5951
5952 ap = a;
5953 vop_fsync_debugprepost(ap->a_vp, "fsync");
5954 }
5955
5956 void
vop_fdatasync_debugpre(void * a)5957 vop_fdatasync_debugpre(void *a)
5958 {
5959 struct vop_fdatasync_args *ap;
5960
5961 ap = a;
5962 vop_fsync_debugprepost(ap->a_vp, "fsync");
5963 }
5964
5965 void
vop_fdatasync_debugpost(void * a,int rc __unused)5966 vop_fdatasync_debugpost(void *a, int rc __unused)
5967 {
5968 struct vop_fdatasync_args *ap;
5969
5970 ap = a;
5971 vop_fsync_debugprepost(ap->a_vp, "fsync");
5972 }
5973
5974 void
vop_strategy_debugpre(void * ap)5975 vop_strategy_debugpre(void *ap)
5976 {
5977 struct vop_strategy_args *a;
5978 struct buf *bp;
5979
5980 a = ap;
5981 bp = a->a_bp;
5982
5983 /*
5984 * Cluster ops lock their component buffers but not the IO container.
5985 */
5986 if ((bp->b_flags & B_CLUSTER) != 0)
5987 return;
5988
5989 if (!KERNEL_PANICKED() && !BUF_ISLOCKED(bp)) {
5990 if (vfs_badlock_print)
5991 printf(
5992 "VOP_STRATEGY: bp is not locked but should be\n");
5993 if (vfs_badlock_ddb)
5994 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5995 }
5996 }
5997
5998 void
vop_lock_debugpre(void * ap)5999 vop_lock_debugpre(void *ap)
6000 {
6001 struct vop_lock1_args *a = ap;
6002
6003 if ((a->a_flags & LK_INTERLOCK) == 0)
6004 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
6005 else
6006 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
6007 }
6008
6009 void
vop_lock_debugpost(void * ap,int rc)6010 vop_lock_debugpost(void *ap, int rc)
6011 {
6012 struct vop_lock1_args *a = ap;
6013
6014 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
6015 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
6016 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
6017 }
6018
6019 void
vop_unlock_debugpre(void * ap)6020 vop_unlock_debugpre(void *ap)
6021 {
6022 struct vop_unlock_args *a = ap;
6023 struct vnode *vp = a->a_vp;
6024
6025 VNPASS(vn_get_state(vp) != VSTATE_UNINITIALIZED, vp);
6026 ASSERT_VOP_LOCKED(vp, "VOP_UNLOCK");
6027 }
6028
6029 void
vop_need_inactive_debugpre(void * ap)6030 vop_need_inactive_debugpre(void *ap)
6031 {
6032 struct vop_need_inactive_args *a = ap;
6033
6034 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
6035 }
6036
6037 void
vop_need_inactive_debugpost(void * ap,int rc)6038 vop_need_inactive_debugpost(void *ap, int rc)
6039 {
6040 struct vop_need_inactive_args *a = ap;
6041
6042 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
6043 }
6044 #endif
6045
6046 void
vop_create_pre(void * ap)6047 vop_create_pre(void *ap)
6048 {
6049 struct vop_create_args *a;
6050 struct vnode *dvp;
6051
6052 a = ap;
6053 dvp = a->a_dvp;
6054 vn_seqc_write_begin(dvp);
6055 }
6056
6057 void
vop_create_post(void * ap,int rc)6058 vop_create_post(void *ap, int rc)
6059 {
6060 struct vop_create_args *a;
6061 struct vnode *dvp;
6062
6063 a = ap;
6064 dvp = a->a_dvp;
6065 vn_seqc_write_end(dvp);
6066 if (!rc)
6067 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6068 }
6069
6070 void
vop_whiteout_pre(void * ap)6071 vop_whiteout_pre(void *ap)
6072 {
6073 struct vop_whiteout_args *a;
6074 struct vnode *dvp;
6075
6076 a = ap;
6077 dvp = a->a_dvp;
6078 vn_seqc_write_begin(dvp);
6079 }
6080
6081 void
vop_whiteout_post(void * ap,int rc)6082 vop_whiteout_post(void *ap, int rc)
6083 {
6084 struct vop_whiteout_args *a;
6085 struct vnode *dvp;
6086
6087 a = ap;
6088 dvp = a->a_dvp;
6089 vn_seqc_write_end(dvp);
6090 }
6091
6092 void
vop_deleteextattr_pre(void * ap)6093 vop_deleteextattr_pre(void *ap)
6094 {
6095 struct vop_deleteextattr_args *a;
6096 struct vnode *vp;
6097
6098 a = ap;
6099 vp = a->a_vp;
6100 vn_seqc_write_begin(vp);
6101 }
6102
6103 void
vop_deleteextattr_post(void * ap,int rc)6104 vop_deleteextattr_post(void *ap, int rc)
6105 {
6106 struct vop_deleteextattr_args *a;
6107 struct vnode *vp;
6108
6109 a = ap;
6110 vp = a->a_vp;
6111 vn_seqc_write_end(vp);
6112 if (!rc)
6113 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
6114 }
6115
6116 void
vop_link_pre(void * ap)6117 vop_link_pre(void *ap)
6118 {
6119 struct vop_link_args *a;
6120 struct vnode *vp, *tdvp;
6121
6122 a = ap;
6123 vp = a->a_vp;
6124 tdvp = a->a_tdvp;
6125 vn_seqc_write_begin(vp);
6126 vn_seqc_write_begin(tdvp);
6127 }
6128
6129 void
vop_link_post(void * ap,int rc)6130 vop_link_post(void *ap, int rc)
6131 {
6132 struct vop_link_args *a;
6133 struct vnode *vp, *tdvp;
6134
6135 a = ap;
6136 vp = a->a_vp;
6137 tdvp = a->a_tdvp;
6138 vn_seqc_write_end(vp);
6139 vn_seqc_write_end(tdvp);
6140 if (!rc) {
6141 VFS_KNOTE_LOCKED(vp, NOTE_LINK);
6142 VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE);
6143 }
6144 }
6145
6146 void
vop_mkdir_pre(void * ap)6147 vop_mkdir_pre(void *ap)
6148 {
6149 struct vop_mkdir_args *a;
6150 struct vnode *dvp;
6151
6152 a = ap;
6153 dvp = a->a_dvp;
6154 vn_seqc_write_begin(dvp);
6155 }
6156
6157 void
vop_mkdir_post(void * ap,int rc)6158 vop_mkdir_post(void *ap, int rc)
6159 {
6160 struct vop_mkdir_args *a;
6161 struct vnode *dvp;
6162
6163 a = ap;
6164 dvp = a->a_dvp;
6165 vn_seqc_write_end(dvp);
6166 if (!rc)
6167 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6168 }
6169
6170 #ifdef DEBUG_VFS_LOCKS
6171 void
vop_mkdir_debugpost(void * ap,int rc)6172 vop_mkdir_debugpost(void *ap, int rc)
6173 {
6174 struct vop_mkdir_args *a;
6175
6176 a = ap;
6177 if (!rc)
6178 cache_validate(a->a_dvp, *a->a_vpp, a->a_cnp);
6179 }
6180 #endif
6181
6182 void
vop_mknod_pre(void * ap)6183 vop_mknod_pre(void *ap)
6184 {
6185 struct vop_mknod_args *a;
6186 struct vnode *dvp;
6187
6188 a = ap;
6189 dvp = a->a_dvp;
6190 vn_seqc_write_begin(dvp);
6191 }
6192
6193 void
vop_mknod_post(void * ap,int rc)6194 vop_mknod_post(void *ap, int rc)
6195 {
6196 struct vop_mknod_args *a;
6197 struct vnode *dvp;
6198
6199 a = ap;
6200 dvp = a->a_dvp;
6201 vn_seqc_write_end(dvp);
6202 if (!rc)
6203 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6204 }
6205
6206 void
vop_reclaim_post(void * ap,int rc)6207 vop_reclaim_post(void *ap, int rc)
6208 {
6209 struct vop_reclaim_args *a;
6210 struct vnode *vp;
6211
6212 a = ap;
6213 vp = a->a_vp;
6214 ASSERT_VOP_IN_SEQC(vp);
6215 if (!rc)
6216 VFS_KNOTE_LOCKED(vp, NOTE_REVOKE);
6217 }
6218
6219 void
vop_remove_pre(void * ap)6220 vop_remove_pre(void *ap)
6221 {
6222 struct vop_remove_args *a;
6223 struct vnode *dvp, *vp;
6224
6225 a = ap;
6226 dvp = a->a_dvp;
6227 vp = a->a_vp;
6228 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
6229 vn_seqc_write_begin(dvp);
6230 vn_seqc_write_begin(vp);
6231 }
6232
6233 void
vop_remove_post(void * ap,int rc)6234 vop_remove_post(void *ap, int rc)
6235 {
6236 struct vop_remove_args *a;
6237 struct vnode *dvp, *vp;
6238
6239 a = ap;
6240 dvp = a->a_dvp;
6241 vp = a->a_vp;
6242 vn_seqc_write_end(dvp);
6243 vn_seqc_write_end(vp);
6244 if (!rc) {
6245 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6246 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6247 }
6248 }
6249
6250 void
vop_rename_post(void * ap,int rc)6251 vop_rename_post(void *ap, int rc)
6252 {
6253 struct vop_rename_args *a = ap;
6254 long hint;
6255
6256 if (!rc) {
6257 hint = NOTE_WRITE;
6258 if (a->a_fdvp == a->a_tdvp) {
6259 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
6260 hint |= NOTE_LINK;
6261 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6262 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6263 } else {
6264 hint |= NOTE_EXTEND;
6265 if (a->a_fvp->v_type == VDIR)
6266 hint |= NOTE_LINK;
6267 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
6268
6269 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
6270 a->a_tvp->v_type == VDIR)
6271 hint &= ~NOTE_LINK;
6272 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
6273 }
6274
6275 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
6276 if (a->a_tvp)
6277 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
6278 }
6279 if (a->a_tdvp != a->a_fdvp)
6280 vdrop(a->a_fdvp);
6281 if (a->a_tvp != a->a_fvp)
6282 vdrop(a->a_fvp);
6283 vdrop(a->a_tdvp);
6284 if (a->a_tvp)
6285 vdrop(a->a_tvp);
6286 }
6287
6288 void
vop_rmdir_pre(void * ap)6289 vop_rmdir_pre(void *ap)
6290 {
6291 struct vop_rmdir_args *a;
6292 struct vnode *dvp, *vp;
6293
6294 a = ap;
6295 dvp = a->a_dvp;
6296 vp = a->a_vp;
6297 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
6298 vn_seqc_write_begin(dvp);
6299 vn_seqc_write_begin(vp);
6300 }
6301
6302 void
vop_rmdir_post(void * ap,int rc)6303 vop_rmdir_post(void *ap, int rc)
6304 {
6305 struct vop_rmdir_args *a;
6306 struct vnode *dvp, *vp;
6307
6308 a = ap;
6309 dvp = a->a_dvp;
6310 vp = a->a_vp;
6311 vn_seqc_write_end(dvp);
6312 vn_seqc_write_end(vp);
6313 if (!rc) {
6314 vp->v_vflag |= VV_UNLINKED;
6315 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
6316 VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
6317 }
6318 }
6319
6320 void
vop_setattr_pre(void * ap)6321 vop_setattr_pre(void *ap)
6322 {
6323 struct vop_setattr_args *a;
6324 struct vnode *vp;
6325
6326 a = ap;
6327 vp = a->a_vp;
6328 vn_seqc_write_begin(vp);
6329 }
6330
6331 void
vop_setattr_post(void * ap,int rc)6332 vop_setattr_post(void *ap, int rc)
6333 {
6334 struct vop_setattr_args *a;
6335 struct vnode *vp;
6336
6337 a = ap;
6338 vp = a->a_vp;
6339 vn_seqc_write_end(vp);
6340 if (!rc)
6341 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6342 }
6343
6344 void
vop_setacl_pre(void * ap)6345 vop_setacl_pre(void *ap)
6346 {
6347 struct vop_setacl_args *a;
6348 struct vnode *vp;
6349
6350 a = ap;
6351 vp = a->a_vp;
6352 vn_seqc_write_begin(vp);
6353 }
6354
6355 void
vop_setacl_post(void * ap,int rc __unused)6356 vop_setacl_post(void *ap, int rc __unused)
6357 {
6358 struct vop_setacl_args *a;
6359 struct vnode *vp;
6360
6361 a = ap;
6362 vp = a->a_vp;
6363 vn_seqc_write_end(vp);
6364 }
6365
6366 void
vop_setextattr_pre(void * ap)6367 vop_setextattr_pre(void *ap)
6368 {
6369 struct vop_setextattr_args *a;
6370 struct vnode *vp;
6371
6372 a = ap;
6373 vp = a->a_vp;
6374 vn_seqc_write_begin(vp);
6375 }
6376
6377 void
vop_setextattr_post(void * ap,int rc)6378 vop_setextattr_post(void *ap, int rc)
6379 {
6380 struct vop_setextattr_args *a;
6381 struct vnode *vp;
6382
6383 a = ap;
6384 vp = a->a_vp;
6385 vn_seqc_write_end(vp);
6386 if (!rc)
6387 VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
6388 }
6389
6390 void
vop_symlink_pre(void * ap)6391 vop_symlink_pre(void *ap)
6392 {
6393 struct vop_symlink_args *a;
6394 struct vnode *dvp;
6395
6396 a = ap;
6397 dvp = a->a_dvp;
6398 vn_seqc_write_begin(dvp);
6399 }
6400
6401 void
vop_symlink_post(void * ap,int rc)6402 vop_symlink_post(void *ap, int rc)
6403 {
6404 struct vop_symlink_args *a;
6405 struct vnode *dvp;
6406
6407 a = ap;
6408 dvp = a->a_dvp;
6409 vn_seqc_write_end(dvp);
6410 if (!rc)
6411 VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
6412 }
6413
6414 void
vop_open_post(void * ap,int rc)6415 vop_open_post(void *ap, int rc)
6416 {
6417 struct vop_open_args *a = ap;
6418
6419 if (!rc)
6420 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
6421 }
6422
6423 void
vop_close_post(void * ap,int rc)6424 vop_close_post(void *ap, int rc)
6425 {
6426 struct vop_close_args *a = ap;
6427
6428 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
6429 !VN_IS_DOOMED(a->a_vp))) {
6430 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
6431 NOTE_CLOSE_WRITE : NOTE_CLOSE);
6432 }
6433 }
6434
6435 void
vop_read_post(void * ap,int rc)6436 vop_read_post(void *ap, int rc)
6437 {
6438 struct vop_read_args *a = ap;
6439
6440 if (!rc)
6441 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6442 }
6443
6444 void
vop_read_pgcache_post(void * ap,int rc)6445 vop_read_pgcache_post(void *ap, int rc)
6446 {
6447 struct vop_read_pgcache_args *a = ap;
6448
6449 if (!rc)
6450 VFS_KNOTE_UNLOCKED(a->a_vp, NOTE_READ);
6451 }
6452
6453 void
vop_readdir_post(void * ap,int rc)6454 vop_readdir_post(void *ap, int rc)
6455 {
6456 struct vop_readdir_args *a = ap;
6457
6458 if (!rc)
6459 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
6460 }
6461
6462 static struct knlist fs_knlist;
6463
6464 static void
vfs_event_init(void * arg)6465 vfs_event_init(void *arg)
6466 {
6467 knlist_init_mtx(&fs_knlist, NULL);
6468 }
6469 /* XXX - correct order? */
6470 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
6471
6472 void
vfs_event_signal(fsid_t * fsid,uint32_t event,intptr_t data __unused)6473 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
6474 {
6475
6476 KNOTE_UNLOCKED(&fs_knlist, event);
6477 }
6478
6479 static int filt_fsattach(struct knote *kn);
6480 static void filt_fsdetach(struct knote *kn);
6481 static int filt_fsevent(struct knote *kn, long hint);
6482
6483 const struct filterops fs_filtops = {
6484 .f_isfd = 0,
6485 .f_attach = filt_fsattach,
6486 .f_detach = filt_fsdetach,
6487 .f_event = filt_fsevent,
6488 };
6489
6490 static int
filt_fsattach(struct knote * kn)6491 filt_fsattach(struct knote *kn)
6492 {
6493
6494 kn->kn_flags |= EV_CLEAR;
6495 knlist_add(&fs_knlist, kn, 0);
6496 return (0);
6497 }
6498
6499 static void
filt_fsdetach(struct knote * kn)6500 filt_fsdetach(struct knote *kn)
6501 {
6502
6503 knlist_remove(&fs_knlist, kn, 0);
6504 }
6505
6506 static int
filt_fsevent(struct knote * kn,long hint)6507 filt_fsevent(struct knote *kn, long hint)
6508 {
6509
6510 kn->kn_fflags |= kn->kn_sfflags & hint;
6511
6512 return (kn->kn_fflags != 0);
6513 }
6514
6515 static int
sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)6516 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
6517 {
6518 struct vfsidctl vc;
6519 int error;
6520 struct mount *mp;
6521
6522 error = SYSCTL_IN(req, &vc, sizeof(vc));
6523 if (error)
6524 return (error);
6525 if (vc.vc_vers != VFS_CTL_VERS1)
6526 return (EINVAL);
6527 mp = vfs_getvfs(&vc.vc_fsid);
6528 if (mp == NULL)
6529 return (ENOENT);
6530 /* ensure that a specific sysctl goes to the right filesystem. */
6531 if (strcmp(vc.vc_fstypename, "*") != 0 &&
6532 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
6533 vfs_rel(mp);
6534 return (EINVAL);
6535 }
6536 VCTLTOREQ(&vc, req);
6537 error = VFS_SYSCTL(mp, vc.vc_op, req);
6538 vfs_rel(mp);
6539 return (error);
6540 }
6541
6542 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | CTLFLAG_WR,
6543 NULL, 0, sysctl_vfs_ctl, "",
6544 "Sysctl by fsid");
6545
6546 /*
6547 * Function to initialize a va_filerev field sensibly.
6548 * XXX: Wouldn't a random number make a lot more sense ??
6549 */
6550 u_quad_t
init_va_filerev(void)6551 init_va_filerev(void)
6552 {
6553 struct bintime bt;
6554
6555 getbinuptime(&bt);
6556 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
6557 }
6558
6559 static int filt_vfsread(struct knote *kn, long hint);
6560 static int filt_vfswrite(struct knote *kn, long hint);
6561 static int filt_vfsvnode(struct knote *kn, long hint);
6562 static void filt_vfsdetach(struct knote *kn);
6563 static int filt_vfsdump(struct proc *p, struct knote *kn,
6564 struct kinfo_knote *kin);
6565
6566 static const struct filterops vfsread_filtops = {
6567 .f_isfd = 1,
6568 .f_detach = filt_vfsdetach,
6569 .f_event = filt_vfsread,
6570 .f_userdump = filt_vfsdump,
6571 };
6572 static const struct filterops vfswrite_filtops = {
6573 .f_isfd = 1,
6574 .f_detach = filt_vfsdetach,
6575 .f_event = filt_vfswrite,
6576 .f_userdump = filt_vfsdump,
6577 };
6578 static const struct filterops vfsvnode_filtops = {
6579 .f_isfd = 1,
6580 .f_detach = filt_vfsdetach,
6581 .f_event = filt_vfsvnode,
6582 .f_userdump = filt_vfsdump,
6583 };
6584
6585 static void
vfs_knllock(void * arg)6586 vfs_knllock(void *arg)
6587 {
6588 struct vnode *vp = arg;
6589
6590 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
6591 }
6592
6593 static void
vfs_knlunlock(void * arg)6594 vfs_knlunlock(void *arg)
6595 {
6596 struct vnode *vp = arg;
6597
6598 VOP_UNLOCK(vp);
6599 }
6600
6601 static void
vfs_knl_assert_lock(void * arg,int what)6602 vfs_knl_assert_lock(void *arg, int what)
6603 {
6604 #ifdef DEBUG_VFS_LOCKS
6605 struct vnode *vp = arg;
6606
6607 if (what == LA_LOCKED)
6608 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
6609 else
6610 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
6611 #endif
6612 }
6613
6614 int
vfs_kqfilter(struct vop_kqfilter_args * ap)6615 vfs_kqfilter(struct vop_kqfilter_args *ap)
6616 {
6617 struct vnode *vp = ap->a_vp;
6618 struct knote *kn = ap->a_kn;
6619 struct knlist *knl;
6620
6621 KASSERT(vp->v_type != VFIFO || (kn->kn_filter != EVFILT_READ &&
6622 kn->kn_filter != EVFILT_WRITE),
6623 ("READ/WRITE filter on a FIFO leaked through"));
6624 switch (kn->kn_filter) {
6625 case EVFILT_READ:
6626 kn->kn_fop = &vfsread_filtops;
6627 break;
6628 case EVFILT_WRITE:
6629 kn->kn_fop = &vfswrite_filtops;
6630 break;
6631 case EVFILT_VNODE:
6632 kn->kn_fop = &vfsvnode_filtops;
6633 break;
6634 default:
6635 return (EINVAL);
6636 }
6637
6638 kn->kn_hook = (caddr_t)vp;
6639
6640 v_addpollinfo(vp);
6641 if (vp->v_pollinfo == NULL)
6642 return (ENOMEM);
6643 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
6644 vhold(vp);
6645 knlist_add(knl, kn, 0);
6646
6647 return (0);
6648 }
6649
6650 /*
6651 * Detach knote from vnode
6652 */
6653 static void
filt_vfsdetach(struct knote * kn)6654 filt_vfsdetach(struct knote *kn)
6655 {
6656 struct vnode *vp = (struct vnode *)kn->kn_hook;
6657
6658 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
6659 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
6660 vdrop(vp);
6661 }
6662
6663 /*ARGSUSED*/
6664 static int
filt_vfsread(struct knote * kn,long hint)6665 filt_vfsread(struct knote *kn, long hint)
6666 {
6667 struct vnode *vp = (struct vnode *)kn->kn_hook;
6668 off_t size;
6669 int res;
6670
6671 /*
6672 * filesystem is gone, so set the EOF flag and schedule
6673 * the knote for deletion.
6674 */
6675 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6676 VI_LOCK(vp);
6677 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6678 VI_UNLOCK(vp);
6679 return (1);
6680 }
6681
6682 if (vn_getsize_locked(vp, &size, curthread->td_ucred) != 0)
6683 return (0);
6684
6685 VI_LOCK(vp);
6686 kn->kn_data = size - kn->kn_fp->f_offset;
6687 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
6688 VI_UNLOCK(vp);
6689 return (res);
6690 }
6691
6692 /*ARGSUSED*/
6693 static int
filt_vfswrite(struct knote * kn,long hint)6694 filt_vfswrite(struct knote *kn, long hint)
6695 {
6696 struct vnode *vp = (struct vnode *)kn->kn_hook;
6697
6698 VI_LOCK(vp);
6699
6700 /*
6701 * filesystem is gone, so set the EOF flag and schedule
6702 * the knote for deletion.
6703 */
6704 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
6705 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
6706
6707 kn->kn_data = 0;
6708 VI_UNLOCK(vp);
6709 return (1);
6710 }
6711
6712 static int
filt_vfsvnode(struct knote * kn,long hint)6713 filt_vfsvnode(struct knote *kn, long hint)
6714 {
6715 struct vnode *vp = (struct vnode *)kn->kn_hook;
6716 int res;
6717
6718 VI_LOCK(vp);
6719 if (kn->kn_sfflags & hint)
6720 kn->kn_fflags |= hint;
6721 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
6722 kn->kn_flags |= EV_EOF;
6723 VI_UNLOCK(vp);
6724 return (1);
6725 }
6726 res = (kn->kn_fflags != 0);
6727 VI_UNLOCK(vp);
6728 return (res);
6729 }
6730
6731 static int
filt_vfsdump(struct proc * p,struct knote * kn,struct kinfo_knote * kin)6732 filt_vfsdump(struct proc *p, struct knote *kn, struct kinfo_knote *kin)
6733 {
6734 struct vattr va;
6735 struct vnode *vp;
6736 char *fullpath, *freepath;
6737 int error;
6738
6739 kin->knt_extdata = KNOTE_EXTDATA_VNODE;
6740
6741 vp = kn->kn_fp->f_vnode;
6742 kin->knt_vnode.knt_vnode_type = vntype_to_kinfo(vp->v_type);
6743
6744 va.va_fsid = VNOVAL;
6745 vn_lock(vp, LK_SHARED | LK_RETRY);
6746 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
6747 VOP_UNLOCK(vp);
6748 if (error != 0)
6749 return (error);
6750 kin->knt_vnode.knt_vnode_fsid = va.va_fsid;
6751 kin->knt_vnode.knt_vnode_fileid = va.va_fileid;
6752
6753 freepath = NULL;
6754 fullpath = "-";
6755 error = vn_fullpath(vp, &fullpath, &freepath);
6756 if (error == 0) {
6757 strlcpy(kin->knt_vnode.knt_vnode_fullpath, fullpath,
6758 sizeof(kin->knt_vnode.knt_vnode_fullpath));
6759 }
6760 if (freepath != NULL)
6761 free(freepath, M_TEMP);
6762
6763 return (0);
6764 }
6765
6766 int
vfs_read_dirent(struct vop_readdir_args * ap,struct dirent * dp,off_t off)6767 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
6768 {
6769 int error;
6770
6771 if (dp->d_reclen > ap->a_uio->uio_resid)
6772 return (ENAMETOOLONG);
6773 error = uiomove(dp, dp->d_reclen, ap->a_uio);
6774 if (error) {
6775 if (ap->a_ncookies != NULL) {
6776 if (ap->a_cookies != NULL)
6777 free(ap->a_cookies, M_TEMP);
6778 ap->a_cookies = NULL;
6779 *ap->a_ncookies = 0;
6780 }
6781 return (error);
6782 }
6783 if (ap->a_ncookies == NULL)
6784 return (0);
6785
6786 KASSERT(ap->a_cookies,
6787 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
6788
6789 *ap->a_cookies = realloc(*ap->a_cookies,
6790 (*ap->a_ncookies + 1) * sizeof(uint64_t), M_TEMP, M_WAITOK | M_ZERO);
6791 (*ap->a_cookies)[*ap->a_ncookies] = off;
6792 *ap->a_ncookies += 1;
6793 return (0);
6794 }
6795
6796 /*
6797 * The purpose of this routine is to remove granularity from accmode_t,
6798 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
6799 * VADMIN and VAPPEND.
6800 *
6801 * If it returns 0, the caller is supposed to continue with the usual
6802 * access checks using 'accmode' as modified by this routine. If it
6803 * returns nonzero value, the caller is supposed to return that value
6804 * as errno.
6805 *
6806 * Note that after this routine runs, accmode may be zero.
6807 */
6808 int
vfs_unixify_accmode(accmode_t * accmode)6809 vfs_unixify_accmode(accmode_t *accmode)
6810 {
6811 /*
6812 * There is no way to specify explicit "deny" rule using
6813 * file mode or POSIX.1e ACLs.
6814 */
6815 if (*accmode & VEXPLICIT_DENY) {
6816 *accmode = 0;
6817 return (0);
6818 }
6819
6820 /*
6821 * None of these can be translated into usual access bits.
6822 * Also, the common case for NFSv4 ACLs is to not contain
6823 * either of these bits. Caller should check for VWRITE
6824 * on the containing directory instead.
6825 */
6826 if (*accmode & (VDELETE_CHILD | VDELETE))
6827 return (EPERM);
6828
6829 if (*accmode & VADMIN_PERMS) {
6830 *accmode &= ~VADMIN_PERMS;
6831 *accmode |= VADMIN;
6832 }
6833
6834 /*
6835 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
6836 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
6837 */
6838 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
6839
6840 return (0);
6841 }
6842
6843 /*
6844 * Clear out a doomed vnode (if any) and replace it with a new one as long
6845 * as the fs is not being unmounted. Return the root vnode to the caller.
6846 */
6847 static int __noinline
vfs_cache_root_fallback(struct mount * mp,int flags,struct vnode ** vpp)6848 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp)
6849 {
6850 struct vnode *vp;
6851 int error;
6852
6853 restart:
6854 if (mp->mnt_rootvnode != NULL) {
6855 MNT_ILOCK(mp);
6856 vp = mp->mnt_rootvnode;
6857 if (vp != NULL) {
6858 if (!VN_IS_DOOMED(vp)) {
6859 vrefact(vp);
6860 MNT_IUNLOCK(mp);
6861 error = vn_lock(vp, flags);
6862 if (error == 0) {
6863 *vpp = vp;
6864 return (0);
6865 }
6866 vrele(vp);
6867 goto restart;
6868 }
6869 /*
6870 * Clear the old one.
6871 */
6872 mp->mnt_rootvnode = NULL;
6873 }
6874 MNT_IUNLOCK(mp);
6875 if (vp != NULL) {
6876 vfs_op_barrier_wait(mp);
6877 vrele(vp);
6878 }
6879 }
6880 error = VFS_CACHEDROOT(mp, flags, vpp);
6881 if (error != 0)
6882 return (error);
6883 if (mp->mnt_vfs_ops == 0) {
6884 MNT_ILOCK(mp);
6885 if (mp->mnt_vfs_ops != 0) {
6886 MNT_IUNLOCK(mp);
6887 return (0);
6888 }
6889 if (mp->mnt_rootvnode == NULL) {
6890 vrefact(*vpp);
6891 mp->mnt_rootvnode = *vpp;
6892 } else {
6893 if (mp->mnt_rootvnode != *vpp) {
6894 if (!VN_IS_DOOMED(mp->mnt_rootvnode)) {
6895 panic("%s: mismatch between vnode returned "
6896 " by VFS_CACHEDROOT and the one cached "
6897 " (%p != %p)",
6898 __func__, *vpp, mp->mnt_rootvnode);
6899 }
6900 }
6901 }
6902 MNT_IUNLOCK(mp);
6903 }
6904 return (0);
6905 }
6906
6907 int
vfs_cache_root(struct mount * mp,int flags,struct vnode ** vpp)6908 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp)
6909 {
6910 struct mount_pcpu *mpcpu;
6911 struct vnode *vp;
6912 int error;
6913
6914 if (!vfs_op_thread_enter(mp, mpcpu))
6915 return (vfs_cache_root_fallback(mp, flags, vpp));
6916 vp = atomic_load_ptr(&mp->mnt_rootvnode);
6917 if (vp == NULL || VN_IS_DOOMED(vp)) {
6918 vfs_op_thread_exit(mp, mpcpu);
6919 return (vfs_cache_root_fallback(mp, flags, vpp));
6920 }
6921 vrefact(vp);
6922 vfs_op_thread_exit(mp, mpcpu);
6923 error = vn_lock(vp, flags);
6924 if (error != 0) {
6925 vrele(vp);
6926 return (vfs_cache_root_fallback(mp, flags, vpp));
6927 }
6928 *vpp = vp;
6929 return (0);
6930 }
6931
6932 struct vnode *
vfs_cache_root_clear(struct mount * mp)6933 vfs_cache_root_clear(struct mount *mp)
6934 {
6935 struct vnode *vp;
6936
6937 /*
6938 * ops > 0 guarantees there is nobody who can see this vnode
6939 */
6940 MPASS(mp->mnt_vfs_ops > 0);
6941 vp = mp->mnt_rootvnode;
6942 if (vp != NULL)
6943 vn_seqc_write_begin(vp);
6944 mp->mnt_rootvnode = NULL;
6945 return (vp);
6946 }
6947
6948 void
vfs_cache_root_set(struct mount * mp,struct vnode * vp)6949 vfs_cache_root_set(struct mount *mp, struct vnode *vp)
6950 {
6951
6952 MPASS(mp->mnt_vfs_ops > 0);
6953 vrefact(vp);
6954 mp->mnt_rootvnode = vp;
6955 }
6956
6957 /*
6958 * These are helper functions for filesystems to traverse all
6959 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
6960 *
6961 * This interface replaces MNT_VNODE_FOREACH.
6962 */
6963
6964 struct vnode *
__mnt_vnode_next_all(struct vnode ** mvp,struct mount * mp)6965 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
6966 {
6967 struct vnode *vp;
6968
6969 maybe_yield();
6970 MNT_ILOCK(mp);
6971 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6972 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL;
6973 vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
6974 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
6975 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
6976 continue;
6977 VI_LOCK(vp);
6978 if (VN_IS_DOOMED(vp)) {
6979 VI_UNLOCK(vp);
6980 continue;
6981 }
6982 break;
6983 }
6984 if (vp == NULL) {
6985 __mnt_vnode_markerfree_all(mvp, mp);
6986 /* MNT_IUNLOCK(mp); -- done in above function */
6987 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
6988 return (NULL);
6989 }
6990 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
6991 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
6992 MNT_IUNLOCK(mp);
6993 return (vp);
6994 }
6995
6996 struct vnode *
__mnt_vnode_first_all(struct vnode ** mvp,struct mount * mp)6997 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
6998 {
6999 struct vnode *vp;
7000
7001 *mvp = vn_alloc_marker(mp);
7002 MNT_ILOCK(mp);
7003 MNT_REF(mp);
7004
7005 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
7006 /* Allow a racy peek at VIRF_DOOMED to save a lock acquisition. */
7007 if (vp->v_type == VMARKER || VN_IS_DOOMED(vp))
7008 continue;
7009 VI_LOCK(vp);
7010 if (VN_IS_DOOMED(vp)) {
7011 VI_UNLOCK(vp);
7012 continue;
7013 }
7014 break;
7015 }
7016 if (vp == NULL) {
7017 MNT_REL(mp);
7018 MNT_IUNLOCK(mp);
7019 vn_free_marker(*mvp);
7020 *mvp = NULL;
7021 return (NULL);
7022 }
7023 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
7024 MNT_IUNLOCK(mp);
7025 return (vp);
7026 }
7027
7028 void
__mnt_vnode_markerfree_all(struct vnode ** mvp,struct mount * mp)7029 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
7030 {
7031
7032 if (*mvp == NULL) {
7033 MNT_IUNLOCK(mp);
7034 return;
7035 }
7036
7037 mtx_assert(MNT_MTX(mp), MA_OWNED);
7038
7039 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
7040 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
7041 MNT_REL(mp);
7042 MNT_IUNLOCK(mp);
7043 vn_free_marker(*mvp);
7044 *mvp = NULL;
7045 }
7046
7047 /*
7048 * These are helper functions for filesystems to traverse their
7049 * lazy vnodes. See MNT_VNODE_FOREACH_LAZY() in sys/mount.h
7050 */
7051 static void
mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)7052 mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
7053 {
7054
7055 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
7056
7057 MNT_ILOCK(mp);
7058 MNT_REL(mp);
7059 MNT_IUNLOCK(mp);
7060 vn_free_marker(*mvp);
7061 *mvp = NULL;
7062 }
7063
7064 /*
7065 * Relock the mp mount vnode list lock with the vp vnode interlock in the
7066 * conventional lock order during mnt_vnode_next_lazy iteration.
7067 *
7068 * On entry, the mount vnode list lock is held and the vnode interlock is not.
7069 * The list lock is dropped and reacquired. On success, both locks are held.
7070 * On failure, the mount vnode list lock is held but the vnode interlock is
7071 * not, and the procedure may have yielded.
7072 */
7073 static bool
mnt_vnode_next_lazy_relock(struct vnode * mvp,struct mount * mp,struct vnode * vp)7074 mnt_vnode_next_lazy_relock(struct vnode *mvp, struct mount *mp,
7075 struct vnode *vp)
7076 {
7077
7078 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER &&
7079 TAILQ_NEXT(mvp, v_lazylist) != NULL, mvp,
7080 ("%s: bad marker", __func__));
7081 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp,
7082 ("%s: inappropriate vnode", __func__));
7083 ASSERT_VI_UNLOCKED(vp, __func__);
7084 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
7085
7086 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, mvp, v_lazylist);
7087 TAILQ_INSERT_BEFORE(vp, mvp, v_lazylist);
7088
7089 /*
7090 * Note we may be racing against vdrop which transitioned the hold
7091 * count to 0 and now waits for the ->mnt_listmtx lock. This is fine,
7092 * if we are the only user after we get the interlock we will just
7093 * vdrop.
7094 */
7095 vhold(vp);
7096 mtx_unlock(&mp->mnt_listmtx);
7097 VI_LOCK(vp);
7098 if (VN_IS_DOOMED(vp)) {
7099 VNPASS((vp->v_mflag & VMP_LAZYLIST) == 0, vp);
7100 goto out_lost;
7101 }
7102 VNPASS(vp->v_mflag & VMP_LAZYLIST, vp);
7103 /*
7104 * There is nothing to do if we are the last user.
7105 */
7106 if (!refcount_release_if_not_last(&vp->v_holdcnt))
7107 goto out_lost;
7108 mtx_lock(&mp->mnt_listmtx);
7109 return (true);
7110 out_lost:
7111 vdropl(vp);
7112 maybe_yield();
7113 mtx_lock(&mp->mnt_listmtx);
7114 return (false);
7115 }
7116
7117 static struct vnode *
mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7118 mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7119 void *cbarg)
7120 {
7121 struct vnode *vp;
7122
7123 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
7124 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
7125 restart:
7126 vp = TAILQ_NEXT(*mvp, v_lazylist);
7127 while (vp != NULL) {
7128 if (vp->v_type == VMARKER) {
7129 vp = TAILQ_NEXT(vp, v_lazylist);
7130 continue;
7131 }
7132 /*
7133 * See if we want to process the vnode. Note we may encounter a
7134 * long string of vnodes we don't care about and hog the list
7135 * as a result. Check for it and requeue the marker.
7136 */
7137 VNPASS(!VN_IS_DOOMED(vp), vp);
7138 if (!cb(vp, cbarg)) {
7139 if (!should_yield()) {
7140 vp = TAILQ_NEXT(vp, v_lazylist);
7141 continue;
7142 }
7143 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp,
7144 v_lazylist);
7145 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp,
7146 v_lazylist);
7147 mtx_unlock(&mp->mnt_listmtx);
7148 kern_yield(PRI_USER);
7149 mtx_lock(&mp->mnt_listmtx);
7150 goto restart;
7151 }
7152 /*
7153 * Try-lock because this is the wrong lock order.
7154 */
7155 if (!VI_TRYLOCK(vp) &&
7156 !mnt_vnode_next_lazy_relock(*mvp, mp, vp))
7157 goto restart;
7158 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
7159 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
7160 ("alien vnode on the lazy list %p %p", vp, mp));
7161 VNPASS(vp->v_mount == mp, vp);
7162 VNPASS(!VN_IS_DOOMED(vp), vp);
7163 break;
7164 }
7165 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7166
7167 /* Check if we are done */
7168 if (vp == NULL) {
7169 mtx_unlock(&mp->mnt_listmtx);
7170 mnt_vnode_markerfree_lazy(mvp, mp);
7171 return (NULL);
7172 }
7173 TAILQ_INSERT_AFTER(&mp->mnt_lazyvnodelist, vp, *mvp, v_lazylist);
7174 mtx_unlock(&mp->mnt_listmtx);
7175 ASSERT_VI_LOCKED(vp, "lazy iter");
7176 return (vp);
7177 }
7178
7179 struct vnode *
__mnt_vnode_next_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7180 __mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7181 void *cbarg)
7182 {
7183
7184 maybe_yield();
7185 mtx_lock(&mp->mnt_listmtx);
7186 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7187 }
7188
7189 struct vnode *
__mnt_vnode_first_lazy(struct vnode ** mvp,struct mount * mp,mnt_lazy_cb_t * cb,void * cbarg)7190 __mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp, mnt_lazy_cb_t *cb,
7191 void *cbarg)
7192 {
7193 struct vnode *vp;
7194
7195 if (TAILQ_EMPTY(&mp->mnt_lazyvnodelist))
7196 return (NULL);
7197
7198 *mvp = vn_alloc_marker(mp);
7199 MNT_ILOCK(mp);
7200 MNT_REF(mp);
7201 MNT_IUNLOCK(mp);
7202
7203 mtx_lock(&mp->mnt_listmtx);
7204 vp = TAILQ_FIRST(&mp->mnt_lazyvnodelist);
7205 if (vp == NULL) {
7206 mtx_unlock(&mp->mnt_listmtx);
7207 mnt_vnode_markerfree_lazy(mvp, mp);
7208 return (NULL);
7209 }
7210 TAILQ_INSERT_BEFORE(vp, *mvp, v_lazylist);
7211 return (mnt_vnode_next_lazy(mvp, mp, cb, cbarg));
7212 }
7213
7214 void
__mnt_vnode_markerfree_lazy(struct vnode ** mvp,struct mount * mp)7215 __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp)
7216 {
7217
7218 if (*mvp == NULL)
7219 return;
7220
7221 mtx_lock(&mp->mnt_listmtx);
7222 TAILQ_REMOVE(&mp->mnt_lazyvnodelist, *mvp, v_lazylist);
7223 mtx_unlock(&mp->mnt_listmtx);
7224 mnt_vnode_markerfree_lazy(mvp, mp);
7225 }
7226
7227 int
vn_dir_check_exec(struct vnode * vp,struct componentname * cnp)7228 vn_dir_check_exec(struct vnode *vp, struct componentname *cnp)
7229 {
7230
7231 if ((cnp->cn_flags & NOEXECCHECK) != 0) {
7232 cnp->cn_flags &= ~NOEXECCHECK;
7233 return (0);
7234 }
7235
7236 return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, curthread));
7237 }
7238
7239 /*
7240 * Do not use this variant unless you have means other than the hold count
7241 * to prevent the vnode from getting freed.
7242 */
7243 void
vn_seqc_write_begin_locked(struct vnode * vp)7244 vn_seqc_write_begin_locked(struct vnode *vp)
7245 {
7246
7247 ASSERT_VI_LOCKED(vp, __func__);
7248 VNPASS(vp->v_holdcnt > 0, vp);
7249 VNPASS(vp->v_seqc_users >= 0, vp);
7250 vp->v_seqc_users++;
7251 if (vp->v_seqc_users == 1)
7252 seqc_sleepable_write_begin(&vp->v_seqc);
7253 }
7254
7255 void
vn_seqc_write_begin(struct vnode * vp)7256 vn_seqc_write_begin(struct vnode *vp)
7257 {
7258
7259 VI_LOCK(vp);
7260 vn_seqc_write_begin_locked(vp);
7261 VI_UNLOCK(vp);
7262 }
7263
7264 void
vn_seqc_write_end_locked(struct vnode * vp)7265 vn_seqc_write_end_locked(struct vnode *vp)
7266 {
7267
7268 ASSERT_VI_LOCKED(vp, __func__);
7269 VNPASS(vp->v_seqc_users > 0, vp);
7270 vp->v_seqc_users--;
7271 if (vp->v_seqc_users == 0)
7272 seqc_sleepable_write_end(&vp->v_seqc);
7273 }
7274
7275 void
vn_seqc_write_end(struct vnode * vp)7276 vn_seqc_write_end(struct vnode *vp)
7277 {
7278
7279 VI_LOCK(vp);
7280 vn_seqc_write_end_locked(vp);
7281 VI_UNLOCK(vp);
7282 }
7283
7284 /*
7285 * Special case handling for allocating and freeing vnodes.
7286 *
7287 * The counter remains unchanged on free so that a doomed vnode will
7288 * keep testing as in modify as long as it is accessible with SMR.
7289 */
7290 static void
vn_seqc_init(struct vnode * vp)7291 vn_seqc_init(struct vnode *vp)
7292 {
7293
7294 vp->v_seqc = 0;
7295 vp->v_seqc_users = 0;
7296 }
7297
7298 static void
vn_seqc_write_end_free(struct vnode * vp)7299 vn_seqc_write_end_free(struct vnode *vp)
7300 {
7301
7302 VNPASS(seqc_in_modify(vp->v_seqc), vp);
7303 VNPASS(vp->v_seqc_users == 1, vp);
7304 }
7305
7306 void
vn_irflag_set_locked(struct vnode * vp,short toset)7307 vn_irflag_set_locked(struct vnode *vp, short toset)
7308 {
7309 short flags;
7310
7311 ASSERT_VI_LOCKED(vp, __func__);
7312 flags = vn_irflag_read(vp);
7313 VNASSERT((flags & toset) == 0, vp,
7314 ("%s: some of the passed flags already set (have %d, passed %d)\n",
7315 __func__, flags, toset));
7316 atomic_store_short(&vp->v_irflag, flags | toset);
7317 }
7318
7319 void
vn_irflag_set(struct vnode * vp,short toset)7320 vn_irflag_set(struct vnode *vp, short toset)
7321 {
7322
7323 VI_LOCK(vp);
7324 vn_irflag_set_locked(vp, toset);
7325 VI_UNLOCK(vp);
7326 }
7327
7328 void
vn_irflag_set_cond_locked(struct vnode * vp,short toset)7329 vn_irflag_set_cond_locked(struct vnode *vp, short toset)
7330 {
7331 short flags;
7332
7333 ASSERT_VI_LOCKED(vp, __func__);
7334 flags = vn_irflag_read(vp);
7335 atomic_store_short(&vp->v_irflag, flags | toset);
7336 }
7337
7338 void
vn_irflag_set_cond(struct vnode * vp,short toset)7339 vn_irflag_set_cond(struct vnode *vp, short toset)
7340 {
7341
7342 VI_LOCK(vp);
7343 vn_irflag_set_cond_locked(vp, toset);
7344 VI_UNLOCK(vp);
7345 }
7346
7347 void
vn_irflag_unset_locked(struct vnode * vp,short tounset)7348 vn_irflag_unset_locked(struct vnode *vp, short tounset)
7349 {
7350 short flags;
7351
7352 ASSERT_VI_LOCKED(vp, __func__);
7353 flags = vn_irflag_read(vp);
7354 VNASSERT((flags & tounset) == tounset, vp,
7355 ("%s: some of the passed flags not set (have %d, passed %d)\n",
7356 __func__, flags, tounset));
7357 atomic_store_short(&vp->v_irflag, flags & ~tounset);
7358 }
7359
7360 void
vn_irflag_unset(struct vnode * vp,short tounset)7361 vn_irflag_unset(struct vnode *vp, short tounset)
7362 {
7363
7364 VI_LOCK(vp);
7365 vn_irflag_unset_locked(vp, tounset);
7366 VI_UNLOCK(vp);
7367 }
7368
7369 int
vn_getsize_locked(struct vnode * vp,off_t * size,struct ucred * cred)7370 vn_getsize_locked(struct vnode *vp, off_t *size, struct ucred *cred)
7371 {
7372 struct vattr vattr;
7373 int error;
7374
7375 ASSERT_VOP_LOCKED(vp, __func__);
7376 error = VOP_GETATTR(vp, &vattr, cred);
7377 if (__predict_true(error == 0)) {
7378 if (vattr.va_size <= OFF_MAX)
7379 *size = vattr.va_size;
7380 else
7381 error = EFBIG;
7382 }
7383 return (error);
7384 }
7385
7386 int
vn_getsize(struct vnode * vp,off_t * size,struct ucred * cred)7387 vn_getsize(struct vnode *vp, off_t *size, struct ucred *cred)
7388 {
7389 int error;
7390
7391 VOP_LOCK(vp, LK_SHARED);
7392 error = vn_getsize_locked(vp, size, cred);
7393 VOP_UNLOCK(vp);
7394 return (error);
7395 }
7396
7397 #ifdef INVARIANTS
7398 void
vn_set_state_validate(struct vnode * vp,__enum_uint8 (vstate)state)7399 vn_set_state_validate(struct vnode *vp, __enum_uint8(vstate) state)
7400 {
7401
7402 switch (vp->v_state) {
7403 case VSTATE_UNINITIALIZED:
7404 switch (state) {
7405 case VSTATE_CONSTRUCTED:
7406 case VSTATE_DESTROYING:
7407 return;
7408 default:
7409 break;
7410 }
7411 break;
7412 case VSTATE_CONSTRUCTED:
7413 ASSERT_VOP_ELOCKED(vp, __func__);
7414 switch (state) {
7415 case VSTATE_DESTROYING:
7416 return;
7417 default:
7418 break;
7419 }
7420 break;
7421 case VSTATE_DESTROYING:
7422 ASSERT_VOP_ELOCKED(vp, __func__);
7423 switch (state) {
7424 case VSTATE_DEAD:
7425 return;
7426 default:
7427 break;
7428 }
7429 break;
7430 case VSTATE_DEAD:
7431 switch (state) {
7432 case VSTATE_UNINITIALIZED:
7433 return;
7434 default:
7435 break;
7436 }
7437 break;
7438 }
7439
7440 vn_printf(vp, "invalid state transition %d -> %d\n", vp->v_state, state);
7441 panic("invalid state transition %d -> %d\n", vp->v_state, state);
7442 }
7443 #endif
7444