FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_subr.c
1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
35 */
36
37 /*
38 * External virtual filesystem routines
39 */
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: releng/11.0/sys/kern/vfs_subr.c 303290 2016-07-25 13:28:59Z kib $");
43
44 #include "opt_compat.h"
45 #include "opt_ddb.h"
46 #include "opt_watchdog.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/bio.h>
51 #include <sys/buf.h>
52 #include <sys/condvar.h>
53 #include <sys/conf.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/lockf.h>
65 #include <sys/malloc.h>
66 #include <sys/mount.h>
67 #include <sys/namei.h>
68 #include <sys/pctrie.h>
69 #include <sys/priv.h>
70 #include <sys/reboot.h>
71 #include <sys/refcount.h>
72 #include <sys/rwlock.h>
73 #include <sys/sched.h>
74 #include <sys/sleepqueue.h>
75 #include <sys/smp.h>
76 #include <sys/stat.h>
77 #include <sys/sysctl.h>
78 #include <sys/syslog.h>
79 #include <sys/vmmeter.h>
80 #include <sys/vnode.h>
81 #include <sys/watchdog.h>
82
83 #include <machine/stdarg.h>
84
85 #include <security/mac/mac_framework.h>
86
87 #include <vm/vm.h>
88 #include <vm/vm_object.h>
89 #include <vm/vm_extern.h>
90 #include <vm/pmap.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_kern.h>
94 #include <vm/uma.h>
95
96 #ifdef DDB
97 #include <ddb/ddb.h>
98 #endif
99
100 static void delmntque(struct vnode *vp);
101 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
102 int slpflag, int slptimeo);
103 static void syncer_shutdown(void *arg, int howto);
104 static int vtryrecycle(struct vnode *vp);
105 static void v_init_counters(struct vnode *);
106 static void v_incr_usecount(struct vnode *);
107 static void v_incr_usecount_locked(struct vnode *);
108 static void v_incr_devcount(struct vnode *);
109 static void v_decr_devcount(struct vnode *);
110 static void vgonel(struct vnode *);
111 static void vfs_knllock(void *arg);
112 static void vfs_knlunlock(void *arg);
113 static void vfs_knl_assert_locked(void *arg);
114 static void vfs_knl_assert_unlocked(void *arg);
115 static void destroy_vpollinfo(struct vpollinfo *vi);
116
117 /*
118 * Number of vnodes in existence. Increased whenever getnewvnode()
119 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
120 */
121 static unsigned long numvnodes;
122
123 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
124 "Number of vnodes in existence");
125
126 static u_long vnodes_created;
127 SYSCTL_ULONG(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
128 0, "Number of vnodes created by getnewvnode");
129
130 /*
131 * Conversion tables for conversion from vnode types to inode formats
132 * and back.
133 */
134 enum vtype iftovt_tab[16] = {
135 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
136 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
137 };
138 int vttoif_tab[10] = {
139 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
140 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
141 };
142
143 /*
144 * List of vnodes that are ready for recycling.
145 */
146 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
147
148 /*
149 * "Free" vnode target. Free vnodes are rarely completely free, but are
150 * just ones that are cheap to recycle. Usually they are for files which
151 * have been stat'd but not read; these usually have inode and namecache
152 * data attached to them. This target is the preferred minimum size of a
153 * sub-cache consisting mostly of such files. The system balances the size
154 * of this sub-cache with its complement to try to prevent either from
155 * thrashing while the other is relatively inactive. The targets express
156 * a preference for the best balance.
157 *
158 * "Above" this target there are 2 further targets (watermarks) related
159 * to recyling of free vnodes. In the best-operating case, the cache is
160 * exactly full, the free list has size between vlowat and vhiwat above the
161 * free target, and recycling from it and normal use maintains this state.
162 * Sometimes the free list is below vlowat or even empty, but this state
163 * is even better for immediate use provided the cache is not full.
164 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
165 * ones) to reach one of these states. The watermarks are currently hard-
166 * coded as 4% and 9% of the available space higher. These and the default
167 * of 25% for wantfreevnodes are too large if the memory size is large.
168 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
169 * whenever vnlru_proc() becomes active.
170 */
171 static u_long wantfreevnodes;
172 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW,
173 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes");
174 static u_long freevnodes;
175 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD,
176 &freevnodes, 0, "Number of \"free\" vnodes");
177
178 static u_long recycles_count;
179 SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 0,
180 "Number of vnodes recycled to meet vnode cache targets");
181
182 /*
183 * Various variables used for debugging the new implementation of
184 * reassignbuf().
185 * XXX these are probably of (very) limited utility now.
186 */
187 static int reassignbufcalls;
188 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
189 "Number of calls to reassignbuf");
190
191 static u_long free_owe_inact;
192 SYSCTL_ULONG(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 0,
193 "Number of times free vnodes kept on active list due to VFS "
194 "owing inactivation");
195
196 /* To keep more than one thread at a time from running vfs_getnewfsid */
197 static struct mtx mntid_mtx;
198
199 /*
200 * Lock for any access to the following:
201 * vnode_free_list
202 * numvnodes
203 * freevnodes
204 */
205 static struct mtx vnode_free_list_mtx;
206
207 /* Publicly exported FS */
208 struct nfs_public nfs_pub;
209
210 static uma_zone_t buf_trie_zone;
211
212 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
213 static uma_zone_t vnode_zone;
214 static uma_zone_t vnodepoll_zone;
215
216 /*
217 * The workitem queue.
218 *
219 * It is useful to delay writes of file data and filesystem metadata
220 * for tens of seconds so that quickly created and deleted files need
221 * not waste disk bandwidth being created and removed. To realize this,
222 * we append vnodes to a "workitem" queue. When running with a soft
223 * updates implementation, most pending metadata dependencies should
224 * not wait for more than a few seconds. Thus, mounted on block devices
225 * are delayed only about a half the time that file data is delayed.
226 * Similarly, directory updates are more critical, so are only delayed
227 * about a third the time that file data is delayed. Thus, there are
228 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
229 * one each second (driven off the filesystem syncer process). The
230 * syncer_delayno variable indicates the next queue that is to be processed.
231 * Items that need to be processed soon are placed in this queue:
232 *
233 * syncer_workitem_pending[syncer_delayno]
234 *
235 * A delay of fifteen seconds is done by placing the request fifteen
236 * entries later in the queue:
237 *
238 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
239 *
240 */
241 static int syncer_delayno;
242 static long syncer_mask;
243 LIST_HEAD(synclist, bufobj);
244 static struct synclist *syncer_workitem_pending;
245 /*
246 * The sync_mtx protects:
247 * bo->bo_synclist
248 * sync_vnode_count
249 * syncer_delayno
250 * syncer_state
251 * syncer_workitem_pending
252 * syncer_worklist_len
253 * rushjob
254 */
255 static struct mtx sync_mtx;
256 static struct cv sync_wakeup;
257
258 #define SYNCER_MAXDELAY 32
259 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
260 static int syncdelay = 30; /* max time to delay syncing data */
261 static int filedelay = 30; /* time to delay syncing files */
262 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
263 "Time to delay syncing files (in seconds)");
264 static int dirdelay = 29; /* time to delay syncing directories */
265 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
266 "Time to delay syncing directories (in seconds)");
267 static int metadelay = 28; /* time to delay syncing metadata */
268 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
269 "Time to delay syncing metadata (in seconds)");
270 static int rushjob; /* number of slots to run ASAP */
271 static int stat_rush_requests; /* number of times I/O speeded up */
272 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
273 "Number of times I/O speeded up (rush requests)");
274
275 /*
276 * When shutting down the syncer, run it at four times normal speed.
277 */
278 #define SYNCER_SHUTDOWN_SPEEDUP 4
279 static int sync_vnode_count;
280 static int syncer_worklist_len;
281 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
282 syncer_state;
283
284 /* Target for maximum number of vnodes. */
285 int desiredvnodes;
286 static int gapvnodes; /* gap between wanted and desired */
287 static int vhiwat; /* enough extras after expansion */
288 static int vlowat; /* minimal extras before expansion */
289 static int vstir; /* nonzero to stir non-free vnodes */
290 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
291
292 static int
293 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS)
294 {
295 int error, old_desiredvnodes;
296
297 old_desiredvnodes = desiredvnodes;
298 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0)
299 return (error);
300 if (old_desiredvnodes != desiredvnodes) {
301 wantfreevnodes = desiredvnodes / 4;
302 /* XXX locking seems to be incomplete. */
303 vfs_hash_changesize(desiredvnodes);
304 cache_changesize(desiredvnodes);
305 }
306 return (0);
307 }
308
309 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
310 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0,
311 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes");
312 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
313 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)");
314 static int vnlru_nowhere;
315 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
316 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
317
318 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
319 static int vnsz2log;
320
321 /*
322 * Support for the bufobj clean & dirty pctrie.
323 */
324 static void *
325 buf_trie_alloc(struct pctrie *ptree)
326 {
327
328 return uma_zalloc(buf_trie_zone, M_NOWAIT);
329 }
330
331 static void
332 buf_trie_free(struct pctrie *ptree, void *node)
333 {
334
335 uma_zfree(buf_trie_zone, node);
336 }
337 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
338
339 /*
340 * Initialize the vnode management data structures.
341 *
342 * Reevaluate the following cap on the number of vnodes after the physical
343 * memory size exceeds 512GB. In the limit, as the physical memory size
344 * grows, the ratio of the memory size in KB to to vnodes approaches 64:1.
345 */
346 #ifndef MAXVNODES_MAX
347 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */
348 #endif
349
350 /*
351 * Initialize a vnode as it first enters the zone.
352 */
353 static int
354 vnode_init(void *mem, int size, int flags)
355 {
356 struct vnode *vp;
357 struct bufobj *bo;
358
359 vp = mem;
360 bzero(vp, size);
361 /*
362 * Setup locks.
363 */
364 vp->v_vnlock = &vp->v_lock;
365 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
366 /*
367 * By default, don't allow shared locks unless filesystems opt-in.
368 */
369 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
370 LK_NOSHARE | LK_IS_VNODE);
371 /*
372 * Initialize bufobj.
373 */
374 bo = &vp->v_bufobj;
375 bo->__bo_vnode = vp;
376 rw_init(BO_LOCKPTR(bo), "bufobj interlock");
377 bo->bo_private = vp;
378 TAILQ_INIT(&bo->bo_clean.bv_hd);
379 TAILQ_INIT(&bo->bo_dirty.bv_hd);
380 /*
381 * Initialize namecache.
382 */
383 LIST_INIT(&vp->v_cache_src);
384 TAILQ_INIT(&vp->v_cache_dst);
385 /*
386 * Initialize rangelocks.
387 */
388 rangelock_init(&vp->v_rl);
389 return (0);
390 }
391
392 /*
393 * Free a vnode when it is cleared from the zone.
394 */
395 static void
396 vnode_fini(void *mem, int size)
397 {
398 struct vnode *vp;
399 struct bufobj *bo;
400
401 vp = mem;
402 rangelock_destroy(&vp->v_rl);
403 lockdestroy(vp->v_vnlock);
404 mtx_destroy(&vp->v_interlock);
405 bo = &vp->v_bufobj;
406 rw_destroy(BO_LOCKPTR(bo));
407 }
408
409 /*
410 * Provide the size of NFS nclnode and NFS fh for calculation of the
411 * vnode memory consumption. The size is specified directly to
412 * eliminate dependency on NFS-private header.
413 *
414 * Other filesystems may use bigger or smaller (like UFS and ZFS)
415 * private inode data, but the NFS-based estimation is ample enough.
416 * Still, we care about differences in the size between 64- and 32-bit
417 * platforms.
418 *
419 * Namecache structure size is heuristically
420 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
421 */
422 #ifdef _LP64
423 #define NFS_NCLNODE_SZ (528 + 64)
424 #define NC_SZ 148
425 #else
426 #define NFS_NCLNODE_SZ (360 + 32)
427 #define NC_SZ 92
428 #endif
429
430 static void
431 vntblinit(void *dummy __unused)
432 {
433 u_int i;
434 int physvnodes, virtvnodes;
435
436 /*
437 * Desiredvnodes is a function of the physical memory size and the
438 * kernel's heap size. Generally speaking, it scales with the
439 * physical memory size. The ratio of desiredvnodes to the physical
440 * memory size is 1:16 until desiredvnodes exceeds 98,304.
441 * Thereafter, the
442 * marginal ratio of desiredvnodes to the physical memory size is
443 * 1:64. However, desiredvnodes is limited by the kernel's heap
444 * size. The memory required by desiredvnodes vnodes and vm objects
445 * must not exceed 1/10th of the kernel's heap size.
446 */
447 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
448 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
449 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
450 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
451 desiredvnodes = min(physvnodes, virtvnodes);
452 if (desiredvnodes > MAXVNODES_MAX) {
453 if (bootverbose)
454 printf("Reducing kern.maxvnodes %d -> %d\n",
455 desiredvnodes, MAXVNODES_MAX);
456 desiredvnodes = MAXVNODES_MAX;
457 }
458 wantfreevnodes = desiredvnodes / 4;
459 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
460 TAILQ_INIT(&vnode_free_list);
461 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
462 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
463 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0);
464 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
465 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
466 /*
467 * Preallocate enough nodes to support one-per buf so that
468 * we can not fail an insert. reassignbuf() callers can not
469 * tolerate the insertion failure.
470 */
471 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
472 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
473 UMA_ZONE_NOFREE | UMA_ZONE_VM);
474 uma_prealloc(buf_trie_zone, nbuf);
475 /*
476 * Initialize the filesystem syncer.
477 */
478 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
479 &syncer_mask);
480 syncer_maxdelay = syncer_mask + 1;
481 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
482 cv_init(&sync_wakeup, "syncer");
483 for (i = 1; i <= sizeof(struct vnode); i <<= 1)
484 vnsz2log++;
485 vnsz2log--;
486 }
487 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
488
489
490 /*
491 * Mark a mount point as busy. Used to synchronize access and to delay
492 * unmounting. Eventually, mountlist_mtx is not released on failure.
493 *
494 * vfs_busy() is a custom lock, it can block the caller.
495 * vfs_busy() only sleeps if the unmount is active on the mount point.
496 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
497 * vnode belonging to mp.
498 *
499 * Lookup uses vfs_busy() to traverse mount points.
500 * root fs var fs
501 * / vnode lock A / vnode lock (/var) D
502 * /var vnode lock B /log vnode lock(/var/log) E
503 * vfs_busy lock C vfs_busy lock F
504 *
505 * Within each file system, the lock order is C->A->B and F->D->E.
506 *
507 * When traversing across mounts, the system follows that lock order:
508 *
509 * C->A->B
510 * |
511 * +->F->D->E
512 *
513 * The lookup() process for namei("/var") illustrates the process:
514 * VOP_LOOKUP() obtains B while A is held
515 * vfs_busy() obtains a shared lock on F while A and B are held
516 * vput() releases lock on B
517 * vput() releases lock on A
518 * VFS_ROOT() obtains lock on D while shared lock on F is held
519 * vfs_unbusy() releases shared lock on F
520 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
521 * Attempt to lock A (instead of vp_crossmp) while D is held would
522 * violate the global order, causing deadlocks.
523 *
524 * dounmount() locks B while F is drained.
525 */
526 int
527 vfs_busy(struct mount *mp, int flags)
528 {
529
530 MPASS((flags & ~MBF_MASK) == 0);
531 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
532
533 MNT_ILOCK(mp);
534 MNT_REF(mp);
535 /*
536 * If mount point is currently being unmounted, sleep until the
537 * mount point fate is decided. If thread doing the unmounting fails,
538 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
539 * that this mount point has survived the unmount attempt and vfs_busy
540 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
541 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
542 * about to be really destroyed. vfs_busy needs to release its
543 * reference on the mount point in this case and return with ENOENT,
544 * telling the caller that mount mount it tried to busy is no longer
545 * valid.
546 */
547 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
548 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
549 MNT_REL(mp);
550 MNT_IUNLOCK(mp);
551 CTR1(KTR_VFS, "%s: failed busying before sleeping",
552 __func__);
553 return (ENOENT);
554 }
555 if (flags & MBF_MNTLSTLOCK)
556 mtx_unlock(&mountlist_mtx);
557 mp->mnt_kern_flag |= MNTK_MWAIT;
558 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
559 if (flags & MBF_MNTLSTLOCK)
560 mtx_lock(&mountlist_mtx);
561 MNT_ILOCK(mp);
562 }
563 if (flags & MBF_MNTLSTLOCK)
564 mtx_unlock(&mountlist_mtx);
565 mp->mnt_lockref++;
566 MNT_IUNLOCK(mp);
567 return (0);
568 }
569
570 /*
571 * Free a busy filesystem.
572 */
573 void
574 vfs_unbusy(struct mount *mp)
575 {
576
577 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
578 MNT_ILOCK(mp);
579 MNT_REL(mp);
580 KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
581 mp->mnt_lockref--;
582 if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
583 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
584 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
585 mp->mnt_kern_flag &= ~MNTK_DRAINING;
586 wakeup(&mp->mnt_lockref);
587 }
588 MNT_IUNLOCK(mp);
589 }
590
591 /*
592 * Lookup a mount point by filesystem identifier.
593 */
594 struct mount *
595 vfs_getvfs(fsid_t *fsid)
596 {
597 struct mount *mp;
598
599 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
600 mtx_lock(&mountlist_mtx);
601 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
602 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
603 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
604 vfs_ref(mp);
605 mtx_unlock(&mountlist_mtx);
606 return (mp);
607 }
608 }
609 mtx_unlock(&mountlist_mtx);
610 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
611 return ((struct mount *) 0);
612 }
613
614 /*
615 * Lookup a mount point by filesystem identifier, busying it before
616 * returning.
617 *
618 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
619 * cache for popular filesystem identifiers. The cache is lockess, using
620 * the fact that struct mount's are never freed. In worst case we may
621 * get pointer to unmounted or even different filesystem, so we have to
622 * check what we got, and go slow way if so.
623 */
624 struct mount *
625 vfs_busyfs(fsid_t *fsid)
626 {
627 #define FSID_CACHE_SIZE 256
628 typedef struct mount * volatile vmp_t;
629 static vmp_t cache[FSID_CACHE_SIZE];
630 struct mount *mp;
631 int error;
632 uint32_t hash;
633
634 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
635 hash = fsid->val[0] ^ fsid->val[1];
636 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
637 mp = cache[hash];
638 if (mp == NULL ||
639 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] ||
640 mp->mnt_stat.f_fsid.val[1] != fsid->val[1])
641 goto slow;
642 if (vfs_busy(mp, 0) != 0) {
643 cache[hash] = NULL;
644 goto slow;
645 }
646 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
647 mp->mnt_stat.f_fsid.val[1] == fsid->val[1])
648 return (mp);
649 else
650 vfs_unbusy(mp);
651
652 slow:
653 mtx_lock(&mountlist_mtx);
654 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
655 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
656 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
657 error = vfs_busy(mp, MBF_MNTLSTLOCK);
658 if (error) {
659 cache[hash] = NULL;
660 mtx_unlock(&mountlist_mtx);
661 return (NULL);
662 }
663 cache[hash] = mp;
664 return (mp);
665 }
666 }
667 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
668 mtx_unlock(&mountlist_mtx);
669 return ((struct mount *) 0);
670 }
671
672 /*
673 * Check if a user can access privileged mount options.
674 */
675 int
676 vfs_suser(struct mount *mp, struct thread *td)
677 {
678 int error;
679
680 /*
681 * If the thread is jailed, but this is not a jail-friendly file
682 * system, deny immediately.
683 */
684 if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
685 return (EPERM);
686
687 /*
688 * If the file system was mounted outside the jail of the calling
689 * thread, deny immediately.
690 */
691 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
692 return (EPERM);
693
694 /*
695 * If file system supports delegated administration, we don't check
696 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
697 * by the file system itself.
698 * If this is not the user that did original mount, we check for
699 * the PRIV_VFS_MOUNT_OWNER privilege.
700 */
701 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
702 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
703 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
704 return (error);
705 }
706 return (0);
707 }
708
709 /*
710 * Get a new unique fsid. Try to make its val[0] unique, since this value
711 * will be used to create fake device numbers for stat(). Also try (but
712 * not so hard) make its val[0] unique mod 2^16, since some emulators only
713 * support 16-bit device numbers. We end up with unique val[0]'s for the
714 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
715 *
716 * Keep in mind that several mounts may be running in parallel. Starting
717 * the search one past where the previous search terminated is both a
718 * micro-optimization and a defense against returning the same fsid to
719 * different mounts.
720 */
721 void
722 vfs_getnewfsid(struct mount *mp)
723 {
724 static uint16_t mntid_base;
725 struct mount *nmp;
726 fsid_t tfsid;
727 int mtype;
728
729 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
730 mtx_lock(&mntid_mtx);
731 mtype = mp->mnt_vfc->vfc_typenum;
732 tfsid.val[1] = mtype;
733 mtype = (mtype & 0xFF) << 24;
734 for (;;) {
735 tfsid.val[0] = makedev(255,
736 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
737 mntid_base++;
738 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
739 break;
740 vfs_rel(nmp);
741 }
742 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
743 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
744 mtx_unlock(&mntid_mtx);
745 }
746
747 /*
748 * Knob to control the precision of file timestamps:
749 *
750 * 0 = seconds only; nanoseconds zeroed.
751 * 1 = seconds and nanoseconds, accurate within 1/HZ.
752 * 2 = seconds and nanoseconds, truncated to microseconds.
753 * >=3 = seconds and nanoseconds, maximum precision.
754 */
755 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
756
757 static int timestamp_precision = TSP_USEC;
758 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
759 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
760 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, "
761 "3+: sec + ns (max. precision))");
762
763 /*
764 * Get a current timestamp.
765 */
766 void
767 vfs_timestamp(struct timespec *tsp)
768 {
769 struct timeval tv;
770
771 switch (timestamp_precision) {
772 case TSP_SEC:
773 tsp->tv_sec = time_second;
774 tsp->tv_nsec = 0;
775 break;
776 case TSP_HZ:
777 getnanotime(tsp);
778 break;
779 case TSP_USEC:
780 microtime(&tv);
781 TIMEVAL_TO_TIMESPEC(&tv, tsp);
782 break;
783 case TSP_NSEC:
784 default:
785 nanotime(tsp);
786 break;
787 }
788 }
789
790 /*
791 * Set vnode attributes to VNOVAL
792 */
793 void
794 vattr_null(struct vattr *vap)
795 {
796
797 vap->va_type = VNON;
798 vap->va_size = VNOVAL;
799 vap->va_bytes = VNOVAL;
800 vap->va_mode = VNOVAL;
801 vap->va_nlink = VNOVAL;
802 vap->va_uid = VNOVAL;
803 vap->va_gid = VNOVAL;
804 vap->va_fsid = VNOVAL;
805 vap->va_fileid = VNOVAL;
806 vap->va_blocksize = VNOVAL;
807 vap->va_rdev = VNOVAL;
808 vap->va_atime.tv_sec = VNOVAL;
809 vap->va_atime.tv_nsec = VNOVAL;
810 vap->va_mtime.tv_sec = VNOVAL;
811 vap->va_mtime.tv_nsec = VNOVAL;
812 vap->va_ctime.tv_sec = VNOVAL;
813 vap->va_ctime.tv_nsec = VNOVAL;
814 vap->va_birthtime.tv_sec = VNOVAL;
815 vap->va_birthtime.tv_nsec = VNOVAL;
816 vap->va_flags = VNOVAL;
817 vap->va_gen = VNOVAL;
818 vap->va_vaflags = 0;
819 }
820
821 /*
822 * This routine is called when we have too many vnodes. It attempts
823 * to free <count> vnodes and will potentially free vnodes that still
824 * have VM backing store (VM backing store is typically the cause
825 * of a vnode blowout so we want to do this). Therefore, this operation
826 * is not considered cheap.
827 *
828 * A number of conditions may prevent a vnode from being reclaimed.
829 * the buffer cache may have references on the vnode, a directory
830 * vnode may still have references due to the namei cache representing
831 * underlying files, or the vnode may be in active use. It is not
832 * desirable to reuse such vnodes. These conditions may cause the
833 * number of vnodes to reach some minimum value regardless of what
834 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
835 */
836 static int
837 vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger)
838 {
839 struct vnode *vp;
840 int count, done, target;
841
842 done = 0;
843 vn_start_write(NULL, &mp, V_WAIT);
844 MNT_ILOCK(mp);
845 count = mp->mnt_nvnodelistsize;
846 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1);
847 target = target / 10 + 1;
848 while (count != 0 && done < target) {
849 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
850 while (vp != NULL && vp->v_type == VMARKER)
851 vp = TAILQ_NEXT(vp, v_nmntvnodes);
852 if (vp == NULL)
853 break;
854 /*
855 * XXX LRU is completely broken for non-free vnodes. First
856 * by calling here in mountpoint order, then by moving
857 * unselected vnodes to the end here, and most grossly by
858 * removing the vlruvp() function that was supposed to
859 * maintain the order. (This function was born broken
860 * since syncer problems prevented it doing anything.) The
861 * order is closer to LRC (C = Created).
862 *
863 * LRU reclaiming of vnodes seems to have last worked in
864 * FreeBSD-3 where LRU wasn't mentioned under any spelling.
865 * Then there was no hold count, and inactive vnodes were
866 * simply put on the free list in LRU order. The separate
867 * lists also break LRU. We prefer to reclaim from the
868 * free list for technical reasons. This tends to thrash
869 * the free list to keep very unrecently used held vnodes.
870 * The problem is mitigated by keeping the free list large.
871 */
872 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
873 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
874 --count;
875 if (!VI_TRYLOCK(vp))
876 goto next_iter;
877 /*
878 * If it's been deconstructed already, it's still
879 * referenced, or it exceeds the trigger, skip it.
880 * Also skip free vnodes. We are trying to make space
881 * to expand the free list, not reduce it.
882 */
883 if (vp->v_usecount ||
884 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
885 ((vp->v_iflag & VI_FREE) != 0) ||
886 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
887 vp->v_object->resident_page_count > trigger)) {
888 VI_UNLOCK(vp);
889 goto next_iter;
890 }
891 MNT_IUNLOCK(mp);
892 vholdl(vp);
893 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
894 vdrop(vp);
895 goto next_iter_mntunlocked;
896 }
897 VI_LOCK(vp);
898 /*
899 * v_usecount may have been bumped after VOP_LOCK() dropped
900 * the vnode interlock and before it was locked again.
901 *
902 * It is not necessary to recheck VI_DOOMED because it can
903 * only be set by another thread that holds both the vnode
904 * lock and vnode interlock. If another thread has the
905 * vnode lock before we get to VOP_LOCK() and obtains the
906 * vnode interlock after VOP_LOCK() drops the vnode
907 * interlock, the other thread will be unable to drop the
908 * vnode lock before our VOP_LOCK() call fails.
909 */
910 if (vp->v_usecount ||
911 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
912 (vp->v_iflag & VI_FREE) != 0 ||
913 (vp->v_object != NULL &&
914 vp->v_object->resident_page_count > trigger)) {
915 VOP_UNLOCK(vp, LK_INTERLOCK);
916 vdrop(vp);
917 goto next_iter_mntunlocked;
918 }
919 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
920 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
921 atomic_add_long(&recycles_count, 1);
922 vgonel(vp);
923 VOP_UNLOCK(vp, 0);
924 vdropl(vp);
925 done++;
926 next_iter_mntunlocked:
927 if (!should_yield())
928 goto relock_mnt;
929 goto yield;
930 next_iter:
931 if (!should_yield())
932 continue;
933 MNT_IUNLOCK(mp);
934 yield:
935 kern_yield(PRI_USER);
936 relock_mnt:
937 MNT_ILOCK(mp);
938 }
939 MNT_IUNLOCK(mp);
940 vn_finished_write(mp);
941 return done;
942 }
943
944 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */
945 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free,
946 0,
947 "limit on vnode free requests per call to the vnlru_free routine");
948
949 /*
950 * Attempt to reduce the free list by the requested amount.
951 */
952 static void
953 vnlru_free_locked(int count, struct vfsops *mnt_op)
954 {
955 struct vnode *vp;
956 struct mount *mp;
957
958 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
959 if (count > max_vnlru_free)
960 count = max_vnlru_free;
961 for (; count > 0; count--) {
962 vp = TAILQ_FIRST(&vnode_free_list);
963 /*
964 * The list can be modified while the free_list_mtx
965 * has been dropped and vp could be NULL here.
966 */
967 if (!vp)
968 break;
969 VNASSERT(vp->v_op != NULL, vp,
970 ("vnlru_free: vnode already reclaimed."));
971 KASSERT((vp->v_iflag & VI_FREE) != 0,
972 ("Removing vnode not on freelist"));
973 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
974 ("Mangling active vnode"));
975 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
976
977 /*
978 * Don't recycle if our vnode is from different type
979 * of mount point. Note that mp is type-safe, the
980 * check does not reach unmapped address even if
981 * vnode is reclaimed.
982 * Don't recycle if we can't get the interlock without
983 * blocking.
984 */
985 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL &&
986 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) {
987 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
988 continue;
989 }
990 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0,
991 vp, ("vp inconsistent on freelist"));
992
993 /*
994 * The clear of VI_FREE prevents activation of the
995 * vnode. There is no sense in putting the vnode on
996 * the mount point active list, only to remove it
997 * later during recycling. Inline the relevant part
998 * of vholdl(), to avoid triggering assertions or
999 * activating.
1000 */
1001 freevnodes--;
1002 vp->v_iflag &= ~VI_FREE;
1003 refcount_acquire(&vp->v_holdcnt);
1004
1005 mtx_unlock(&vnode_free_list_mtx);
1006 VI_UNLOCK(vp);
1007 vtryrecycle(vp);
1008 /*
1009 * If the recycled succeeded this vdrop will actually free
1010 * the vnode. If not it will simply place it back on
1011 * the free list.
1012 */
1013 vdrop(vp);
1014 mtx_lock(&vnode_free_list_mtx);
1015 }
1016 }
1017
1018 void
1019 vnlru_free(int count, struct vfsops *mnt_op)
1020 {
1021
1022 mtx_lock(&vnode_free_list_mtx);
1023 vnlru_free_locked(count, mnt_op);
1024 mtx_unlock(&vnode_free_list_mtx);
1025 }
1026
1027
1028 /* XXX some names and initialization are bad for limits and watermarks. */
1029 static int
1030 vspace(void)
1031 {
1032 int space;
1033
1034 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1035 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1036 vlowat = vhiwat / 2;
1037 if (numvnodes > desiredvnodes)
1038 return (0);
1039 space = desiredvnodes - numvnodes;
1040 if (freevnodes > wantfreevnodes)
1041 space += freevnodes - wantfreevnodes;
1042 return (space);
1043 }
1044
1045 /*
1046 * Attempt to recycle vnodes in a context that is always safe to block.
1047 * Calling vlrurecycle() from the bowels of filesystem code has some
1048 * interesting deadlock problems.
1049 */
1050 static struct proc *vnlruproc;
1051 static int vnlruproc_sig;
1052
1053 static void
1054 vnlru_proc(void)
1055 {
1056 struct mount *mp, *nmp;
1057 unsigned long ofreevnodes, onumvnodes;
1058 int done, force, reclaim_nc_src, trigger, usevnodes;
1059
1060 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1061 SHUTDOWN_PRI_FIRST);
1062
1063 force = 0;
1064 for (;;) {
1065 kproc_suspend_check(vnlruproc);
1066 mtx_lock(&vnode_free_list_mtx);
1067 /*
1068 * If numvnodes is too large (due to desiredvnodes being
1069 * adjusted using its sysctl, or emergency growth), first
1070 * try to reduce it by discarding from the free list.
1071 */
1072 if (numvnodes > desiredvnodes && freevnodes > 0)
1073 vnlru_free_locked(ulmin(numvnodes - desiredvnodes,
1074 freevnodes), NULL);
1075 /*
1076 * Sleep if the vnode cache is in a good state. This is
1077 * when it is not over-full and has space for about a 4%
1078 * or 9% expansion (by growing its size or inexcessively
1079 * reducing its free list). Otherwise, try to reclaim
1080 * space for a 10% expansion.
1081 */
1082 if (vstir && force == 0) {
1083 force = 1;
1084 vstir = 0;
1085 }
1086 if (vspace() >= vlowat && force == 0) {
1087 vnlruproc_sig = 0;
1088 wakeup(&vnlruproc_sig);
1089 msleep(vnlruproc, &vnode_free_list_mtx,
1090 PVFS|PDROP, "vlruwt", hz);
1091 continue;
1092 }
1093 mtx_unlock(&vnode_free_list_mtx);
1094 done = 0;
1095 ofreevnodes = freevnodes;
1096 onumvnodes = numvnodes;
1097 /*
1098 * Calculate parameters for recycling. These are the same
1099 * throughout the loop to give some semblance of fairness.
1100 * The trigger point is to avoid recycling vnodes with lots
1101 * of resident pages. We aren't trying to free memory; we
1102 * are trying to recycle or at least free vnodes.
1103 */
1104 if (numvnodes <= desiredvnodes)
1105 usevnodes = numvnodes - freevnodes;
1106 else
1107 usevnodes = numvnodes;
1108 if (usevnodes <= 0)
1109 usevnodes = 1;
1110 /*
1111 * The trigger value is is chosen to give a conservatively
1112 * large value to ensure that it alone doesn't prevent
1113 * making progress. The value can easily be so large that
1114 * it is effectively infinite in some congested and
1115 * misconfigured cases, and this is necessary. Normally
1116 * it is about 8 to 100 (pages), which is quite large.
1117 */
1118 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1119 if (force < 2)
1120 trigger = vsmalltrigger;
1121 reclaim_nc_src = force >= 3;
1122 mtx_lock(&mountlist_mtx);
1123 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1124 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
1125 nmp = TAILQ_NEXT(mp, mnt_list);
1126 continue;
1127 }
1128 done += vlrureclaim(mp, reclaim_nc_src, trigger);
1129 mtx_lock(&mountlist_mtx);
1130 nmp = TAILQ_NEXT(mp, mnt_list);
1131 vfs_unbusy(mp);
1132 }
1133 mtx_unlock(&mountlist_mtx);
1134 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes)
1135 uma_reclaim();
1136 if (done == 0) {
1137 if (force == 0 || force == 1) {
1138 force = 2;
1139 continue;
1140 }
1141 if (force == 2) {
1142 force = 3;
1143 continue;
1144 }
1145 force = 0;
1146 vnlru_nowhere++;
1147 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1148 } else
1149 kern_yield(PRI_USER);
1150 /*
1151 * After becoming active to expand above low water, keep
1152 * active until above high water.
1153 */
1154 force = vspace() < vhiwat;
1155 }
1156 }
1157
1158 static struct kproc_desc vnlru_kp = {
1159 "vnlru",
1160 vnlru_proc,
1161 &vnlruproc
1162 };
1163 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1164 &vnlru_kp);
1165
1166 /*
1167 * Routines having to do with the management of the vnode table.
1168 */
1169
1170 /*
1171 * Try to recycle a freed vnode. We abort if anyone picks up a reference
1172 * before we actually vgone(). This function must be called with the vnode
1173 * held to prevent the vnode from being returned to the free list midway
1174 * through vgone().
1175 */
1176 static int
1177 vtryrecycle(struct vnode *vp)
1178 {
1179 struct mount *vnmp;
1180
1181 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1182 VNASSERT(vp->v_holdcnt, vp,
1183 ("vtryrecycle: Recycling vp %p without a reference.", vp));
1184 /*
1185 * This vnode may found and locked via some other list, if so we
1186 * can't recycle it yet.
1187 */
1188 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1189 CTR2(KTR_VFS,
1190 "%s: impossible to recycle, vp %p lock is already held",
1191 __func__, vp);
1192 return (EWOULDBLOCK);
1193 }
1194 /*
1195 * Don't recycle if its filesystem is being suspended.
1196 */
1197 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1198 VOP_UNLOCK(vp, 0);
1199 CTR2(KTR_VFS,
1200 "%s: impossible to recycle, cannot start the write for %p",
1201 __func__, vp);
1202 return (EBUSY);
1203 }
1204 /*
1205 * If we got this far, we need to acquire the interlock and see if
1206 * anyone picked up this vnode from another list. If not, we will
1207 * mark it with DOOMED via vgonel() so that anyone who does find it
1208 * will skip over it.
1209 */
1210 VI_LOCK(vp);
1211 if (vp->v_usecount) {
1212 VOP_UNLOCK(vp, LK_INTERLOCK);
1213 vn_finished_write(vnmp);
1214 CTR2(KTR_VFS,
1215 "%s: impossible to recycle, %p is already referenced",
1216 __func__, vp);
1217 return (EBUSY);
1218 }
1219 if ((vp->v_iflag & VI_DOOMED) == 0) {
1220 atomic_add_long(&recycles_count, 1);
1221 vgonel(vp);
1222 }
1223 VOP_UNLOCK(vp, LK_INTERLOCK);
1224 vn_finished_write(vnmp);
1225 return (0);
1226 }
1227
1228 static void
1229 vcheckspace(void)
1230 {
1231
1232 if (vspace() < vlowat && vnlruproc_sig == 0) {
1233 vnlruproc_sig = 1;
1234 wakeup(vnlruproc);
1235 }
1236 }
1237
1238 /*
1239 * Wait if necessary for space for a new vnode.
1240 */
1241 static int
1242 getnewvnode_wait(int suspended)
1243 {
1244
1245 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
1246 if (numvnodes >= desiredvnodes) {
1247 if (suspended) {
1248 /*
1249 * The file system is being suspended. We cannot
1250 * risk a deadlock here, so allow allocation of
1251 * another vnode even if this would give too many.
1252 */
1253 return (0);
1254 }
1255 if (vnlruproc_sig == 0) {
1256 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
1257 wakeup(vnlruproc);
1258 }
1259 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
1260 "vlruwk", hz);
1261 }
1262 /* Post-adjust like the pre-adjust in getnewvnode(). */
1263 if (numvnodes + 1 > desiredvnodes && freevnodes > 1)
1264 vnlru_free_locked(1, NULL);
1265 return (numvnodes >= desiredvnodes ? ENFILE : 0);
1266 }
1267
1268 /*
1269 * This hack is fragile, and probably not needed any more now that the
1270 * watermark handling works.
1271 */
1272 void
1273 getnewvnode_reserve(u_int count)
1274 {
1275 struct thread *td;
1276
1277 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */
1278 /* XXX no longer so quick, but this part is not racy. */
1279 mtx_lock(&vnode_free_list_mtx);
1280 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes)
1281 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes,
1282 freevnodes - wantfreevnodes), NULL);
1283 mtx_unlock(&vnode_free_list_mtx);
1284
1285 td = curthread;
1286 /* First try to be quick and racy. */
1287 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) {
1288 td->td_vp_reserv += count;
1289 vcheckspace(); /* XXX no longer so quick, but more racy */
1290 return;
1291 } else
1292 atomic_subtract_long(&numvnodes, count);
1293
1294 mtx_lock(&vnode_free_list_mtx);
1295 while (count > 0) {
1296 if (getnewvnode_wait(0) == 0) {
1297 count--;
1298 td->td_vp_reserv++;
1299 atomic_add_long(&numvnodes, 1);
1300 }
1301 }
1302 vcheckspace();
1303 mtx_unlock(&vnode_free_list_mtx);
1304 }
1305
1306 /*
1307 * This hack is fragile, especially if desiredvnodes or wantvnodes are
1308 * misconfgured or changed significantly. Reducing desiredvnodes below
1309 * the reserved amount should cause bizarre behaviour like reducing it
1310 * below the number of active vnodes -- the system will try to reduce
1311 * numvnodes to match, but should fail, so the subtraction below should
1312 * not overflow.
1313 */
1314 void
1315 getnewvnode_drop_reserve(void)
1316 {
1317 struct thread *td;
1318
1319 td = curthread;
1320 atomic_subtract_long(&numvnodes, td->td_vp_reserv);
1321 td->td_vp_reserv = 0;
1322 }
1323
1324 /*
1325 * Return the next vnode from the free list.
1326 */
1327 int
1328 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
1329 struct vnode **vpp)
1330 {
1331 struct vnode *vp;
1332 struct thread *td;
1333 struct lock_object *lo;
1334 static int cyclecount;
1335 int error;
1336
1337 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
1338 vp = NULL;
1339 td = curthread;
1340 if (td->td_vp_reserv > 0) {
1341 td->td_vp_reserv -= 1;
1342 goto alloc;
1343 }
1344 mtx_lock(&vnode_free_list_mtx);
1345 if (numvnodes < desiredvnodes)
1346 cyclecount = 0;
1347 else if (cyclecount++ >= freevnodes) {
1348 cyclecount = 0;
1349 vstir = 1;
1350 }
1351 /*
1352 * Grow the vnode cache if it will not be above its target max
1353 * after growing. Otherwise, if the free list is nonempty, try
1354 * to reclaim 1 item from it before growing the cache (possibly
1355 * above its target max if the reclamation failed or is delayed).
1356 * Otherwise, wait for some space. In all cases, schedule
1357 * vnlru_proc() if we are getting short of space. The watermarks
1358 * should be chosen so that we never wait or even reclaim from
1359 * the free list to below its target minimum.
1360 */
1361 if (numvnodes + 1 <= desiredvnodes)
1362 ;
1363 else if (freevnodes > 0)
1364 vnlru_free_locked(1, NULL);
1365 else {
1366 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag &
1367 MNTK_SUSPEND));
1368 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
1369 if (error != 0) {
1370 mtx_unlock(&vnode_free_list_mtx);
1371 return (error);
1372 }
1373 #endif
1374 }
1375 vcheckspace();
1376 atomic_add_long(&numvnodes, 1);
1377 mtx_unlock(&vnode_free_list_mtx);
1378 alloc:
1379 atomic_add_long(&vnodes_created, 1);
1380 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK);
1381 /*
1382 * Locks are given the generic name "vnode" when created.
1383 * Follow the historic practice of using the filesystem
1384 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
1385 *
1386 * Locks live in a witness group keyed on their name. Thus,
1387 * when a lock is renamed, it must also move from the witness
1388 * group of its old name to the witness group of its new name.
1389 *
1390 * The change only needs to be made when the vnode moves
1391 * from one filesystem type to another. We ensure that each
1392 * filesystem use a single static name pointer for its tag so
1393 * that we can compare pointers rather than doing a strcmp().
1394 */
1395 lo = &vp->v_vnlock->lock_object;
1396 if (lo->lo_name != tag) {
1397 lo->lo_name = tag;
1398 WITNESS_DESTROY(lo);
1399 WITNESS_INIT(lo, tag);
1400 }
1401 /*
1402 * By default, don't allow shared locks unless filesystems opt-in.
1403 */
1404 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
1405 /*
1406 * Finalize various vnode identity bits.
1407 */
1408 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
1409 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
1410 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
1411 vp->v_type = VNON;
1412 vp->v_tag = tag;
1413 vp->v_op = vops;
1414 v_init_counters(vp);
1415 vp->v_bufobj.bo_ops = &buf_ops_bio;
1416 #ifdef MAC
1417 mac_vnode_init(vp);
1418 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1419 mac_vnode_associate_singlelabel(mp, vp);
1420 else if (mp == NULL && vops != &dead_vnodeops)
1421 printf("NULL mp in getnewvnode()\n");
1422 #endif
1423 if (mp != NULL) {
1424 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
1425 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1426 vp->v_vflag |= VV_NOKNOTE;
1427 }
1428
1429 /*
1430 * For the filesystems which do not use vfs_hash_insert(),
1431 * still initialize v_hash to have vfs_hash_index() useful.
1432 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
1433 * its own hashing.
1434 */
1435 vp->v_hash = (uintptr_t)vp >> vnsz2log;
1436
1437 *vpp = vp;
1438 return (0);
1439 }
1440
1441 /*
1442 * Delete from old mount point vnode list, if on one.
1443 */
1444 static void
1445 delmntque(struct vnode *vp)
1446 {
1447 struct mount *mp;
1448 int active;
1449
1450 mp = vp->v_mount;
1451 if (mp == NULL)
1452 return;
1453 MNT_ILOCK(mp);
1454 VI_LOCK(vp);
1455 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
1456 ("Active vnode list size %d > Vnode list size %d",
1457 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
1458 active = vp->v_iflag & VI_ACTIVE;
1459 vp->v_iflag &= ~VI_ACTIVE;
1460 if (active) {
1461 mtx_lock(&vnode_free_list_mtx);
1462 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
1463 mp->mnt_activevnodelistsize--;
1464 mtx_unlock(&vnode_free_list_mtx);
1465 }
1466 vp->v_mount = NULL;
1467 VI_UNLOCK(vp);
1468 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1469 ("bad mount point vnode list size"));
1470 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1471 mp->mnt_nvnodelistsize--;
1472 MNT_REL(mp);
1473 MNT_IUNLOCK(mp);
1474 }
1475
1476 static void
1477 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1478 {
1479
1480 vp->v_data = NULL;
1481 vp->v_op = &dead_vnodeops;
1482 vgone(vp);
1483 vput(vp);
1484 }
1485
1486 /*
1487 * Insert into list of vnodes for the new mount point, if available.
1488 */
1489 int
1490 insmntque1(struct vnode *vp, struct mount *mp,
1491 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1492 {
1493
1494 KASSERT(vp->v_mount == NULL,
1495 ("insmntque: vnode already on per mount vnode list"));
1496 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1497 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
1498
1499 /*
1500 * We acquire the vnode interlock early to ensure that the
1501 * vnode cannot be recycled by another process releasing a
1502 * holdcnt on it before we get it on both the vnode list
1503 * and the active vnode list. The mount mutex protects only
1504 * manipulation of the vnode list and the vnode freelist
1505 * mutex protects only manipulation of the active vnode list.
1506 * Hence the need to hold the vnode interlock throughout.
1507 */
1508 MNT_ILOCK(mp);
1509 VI_LOCK(vp);
1510 if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
1511 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1512 mp->mnt_nvnodelistsize == 0)) &&
1513 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
1514 VI_UNLOCK(vp);
1515 MNT_IUNLOCK(mp);
1516 if (dtr != NULL)
1517 dtr(vp, dtr_arg);
1518 return (EBUSY);
1519 }
1520 vp->v_mount = mp;
1521 MNT_REF(mp);
1522 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1523 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1524 ("neg mount point vnode list size"));
1525 mp->mnt_nvnodelistsize++;
1526 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1527 ("Activating already active vnode"));
1528 vp->v_iflag |= VI_ACTIVE;
1529 mtx_lock(&vnode_free_list_mtx);
1530 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
1531 mp->mnt_activevnodelistsize++;
1532 mtx_unlock(&vnode_free_list_mtx);
1533 VI_UNLOCK(vp);
1534 MNT_IUNLOCK(mp);
1535 return (0);
1536 }
1537
1538 int
1539 insmntque(struct vnode *vp, struct mount *mp)
1540 {
1541
1542 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1543 }
1544
1545 /*
1546 * Flush out and invalidate all buffers associated with a bufobj
1547 * Called with the underlying object locked.
1548 */
1549 int
1550 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1551 {
1552 int error;
1553
1554 BO_LOCK(bo);
1555 if (flags & V_SAVE) {
1556 error = bufobj_wwait(bo, slpflag, slptimeo);
1557 if (error) {
1558 BO_UNLOCK(bo);
1559 return (error);
1560 }
1561 if (bo->bo_dirty.bv_cnt > 0) {
1562 BO_UNLOCK(bo);
1563 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1564 return (error);
1565 /*
1566 * XXX We could save a lock/unlock if this was only
1567 * enabled under INVARIANTS
1568 */
1569 BO_LOCK(bo);
1570 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1571 panic("vinvalbuf: dirty bufs");
1572 }
1573 }
1574 /*
1575 * If you alter this loop please notice that interlock is dropped and
1576 * reacquired in flushbuflist. Special care is needed to ensure that
1577 * no race conditions occur from this.
1578 */
1579 do {
1580 error = flushbuflist(&bo->bo_clean,
1581 flags, bo, slpflag, slptimeo);
1582 if (error == 0 && !(flags & V_CLEANONLY))
1583 error = flushbuflist(&bo->bo_dirty,
1584 flags, bo, slpflag, slptimeo);
1585 if (error != 0 && error != EAGAIN) {
1586 BO_UNLOCK(bo);
1587 return (error);
1588 }
1589 } while (error != 0);
1590
1591 /*
1592 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1593 * have write I/O in-progress but if there is a VM object then the
1594 * VM object can also have read-I/O in-progress.
1595 */
1596 do {
1597 bufobj_wwait(bo, 0, 0);
1598 BO_UNLOCK(bo);
1599 if (bo->bo_object != NULL) {
1600 VM_OBJECT_WLOCK(bo->bo_object);
1601 vm_object_pip_wait(bo->bo_object, "bovlbx");
1602 VM_OBJECT_WUNLOCK(bo->bo_object);
1603 }
1604 BO_LOCK(bo);
1605 } while (bo->bo_numoutput > 0);
1606 BO_UNLOCK(bo);
1607
1608 /*
1609 * Destroy the copy in the VM cache, too.
1610 */
1611 if (bo->bo_object != NULL &&
1612 (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
1613 VM_OBJECT_WLOCK(bo->bo_object);
1614 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
1615 OBJPR_CLEANONLY : 0);
1616 VM_OBJECT_WUNLOCK(bo->bo_object);
1617 }
1618
1619 #ifdef INVARIANTS
1620 BO_LOCK(bo);
1621 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
1622 (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
1623 panic("vinvalbuf: flush failed");
1624 BO_UNLOCK(bo);
1625 #endif
1626 return (0);
1627 }
1628
1629 /*
1630 * Flush out and invalidate all buffers associated with a vnode.
1631 * Called with the underlying object locked.
1632 */
1633 int
1634 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1635 {
1636
1637 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1638 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1639 if (vp->v_object != NULL && vp->v_object->handle != vp)
1640 return (0);
1641 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1642 }
1643
1644 /*
1645 * Flush out buffers on the specified list.
1646 *
1647 */
1648 static int
1649 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1650 int slptimeo)
1651 {
1652 struct buf *bp, *nbp;
1653 int retval, error;
1654 daddr_t lblkno;
1655 b_xflags_t xflags;
1656
1657 ASSERT_BO_WLOCKED(bo);
1658
1659 retval = 0;
1660 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1661 if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
1662 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
1663 continue;
1664 }
1665 lblkno = 0;
1666 xflags = 0;
1667 if (nbp != NULL) {
1668 lblkno = nbp->b_lblkno;
1669 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
1670 }
1671 retval = EAGAIN;
1672 error = BUF_TIMELOCK(bp,
1673 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
1674 "flushbuf", slpflag, slptimeo);
1675 if (error) {
1676 BO_LOCK(bo);
1677 return (error != ENOLCK ? error : EAGAIN);
1678 }
1679 KASSERT(bp->b_bufobj == bo,
1680 ("bp %p wrong b_bufobj %p should be %p",
1681 bp, bp->b_bufobj, bo));
1682 /*
1683 * XXX Since there are no node locks for NFS, I
1684 * believe there is a slight chance that a delayed
1685 * write will occur while sleeping just above, so
1686 * check for it.
1687 */
1688 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1689 (flags & V_SAVE)) {
1690 bremfree(bp);
1691 bp->b_flags |= B_ASYNC;
1692 bwrite(bp);
1693 BO_LOCK(bo);
1694 return (EAGAIN); /* XXX: why not loop ? */
1695 }
1696 bremfree(bp);
1697 bp->b_flags |= (B_INVAL | B_RELBUF);
1698 bp->b_flags &= ~B_ASYNC;
1699 brelse(bp);
1700 BO_LOCK(bo);
1701 nbp = gbincore(bo, lblkno);
1702 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1703 != xflags)
1704 break; /* nbp invalid */
1705 }
1706 return (retval);
1707 }
1708
1709 int
1710 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
1711 {
1712 struct buf *bp;
1713 int error;
1714 daddr_t lblkno;
1715
1716 ASSERT_BO_LOCKED(bo);
1717
1718 for (lblkno = startn;;) {
1719 again:
1720 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
1721 if (bp == NULL || bp->b_lblkno >= endn ||
1722 bp->b_lblkno < startn)
1723 break;
1724 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
1725 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
1726 if (error != 0) {
1727 BO_RLOCK(bo);
1728 if (error == ENOLCK)
1729 goto again;
1730 return (error);
1731 }
1732 KASSERT(bp->b_bufobj == bo,
1733 ("bp %p wrong b_bufobj %p should be %p",
1734 bp, bp->b_bufobj, bo));
1735 lblkno = bp->b_lblkno + 1;
1736 if ((bp->b_flags & B_MANAGED) == 0)
1737 bremfree(bp);
1738 bp->b_flags |= B_RELBUF;
1739 /*
1740 * In the VMIO case, use the B_NOREUSE flag to hint that the
1741 * pages backing each buffer in the range are unlikely to be
1742 * reused. Dirty buffers will have the hint applied once
1743 * they've been written.
1744 */
1745 if (bp->b_vp->v_object != NULL)
1746 bp->b_flags |= B_NOREUSE;
1747 brelse(bp);
1748 BO_RLOCK(bo);
1749 }
1750 return (0);
1751 }
1752
1753 /*
1754 * Truncate a file's buffer and pages to a specified length. This
1755 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1756 * sync activity.
1757 */
1758 int
1759 vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize)
1760 {
1761 struct buf *bp, *nbp;
1762 int anyfreed;
1763 int trunclbn;
1764 struct bufobj *bo;
1765
1766 CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__,
1767 vp, cred, blksize, (uintmax_t)length);
1768
1769 /*
1770 * Round up to the *next* lbn.
1771 */
1772 trunclbn = howmany(length, blksize);
1773
1774 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
1775 restart:
1776 bo = &vp->v_bufobj;
1777 BO_LOCK(bo);
1778 anyfreed = 1;
1779 for (;anyfreed;) {
1780 anyfreed = 0;
1781 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
1782 if (bp->b_lblkno < trunclbn)
1783 continue;
1784 if (BUF_LOCK(bp,
1785 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1786 BO_LOCKPTR(bo)) == ENOLCK)
1787 goto restart;
1788
1789 bremfree(bp);
1790 bp->b_flags |= (B_INVAL | B_RELBUF);
1791 bp->b_flags &= ~B_ASYNC;
1792 brelse(bp);
1793 anyfreed = 1;
1794
1795 BO_LOCK(bo);
1796 if (nbp != NULL &&
1797 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
1798 (nbp->b_vp != vp) ||
1799 (nbp->b_flags & B_DELWRI))) {
1800 BO_UNLOCK(bo);
1801 goto restart;
1802 }
1803 }
1804
1805 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1806 if (bp->b_lblkno < trunclbn)
1807 continue;
1808 if (BUF_LOCK(bp,
1809 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1810 BO_LOCKPTR(bo)) == ENOLCK)
1811 goto restart;
1812 bremfree(bp);
1813 bp->b_flags |= (B_INVAL | B_RELBUF);
1814 bp->b_flags &= ~B_ASYNC;
1815 brelse(bp);
1816 anyfreed = 1;
1817
1818 BO_LOCK(bo);
1819 if (nbp != NULL &&
1820 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
1821 (nbp->b_vp != vp) ||
1822 (nbp->b_flags & B_DELWRI) == 0)) {
1823 BO_UNLOCK(bo);
1824 goto restart;
1825 }
1826 }
1827 }
1828
1829 if (length > 0) {
1830 restartsync:
1831 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
1832 if (bp->b_lblkno > 0)
1833 continue;
1834 /*
1835 * Since we hold the vnode lock this should only
1836 * fail if we're racing with the buf daemon.
1837 */
1838 if (BUF_LOCK(bp,
1839 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
1840 BO_LOCKPTR(bo)) == ENOLCK) {
1841 goto restart;
1842 }
1843 VNASSERT((bp->b_flags & B_DELWRI), vp,
1844 ("buf(%p) on dirty queue without DELWRI", bp));
1845
1846 bremfree(bp);
1847 bawrite(bp);
1848 BO_LOCK(bo);
1849 goto restartsync;
1850 }
1851 }
1852
1853 bufobj_wwait(bo, 0, 0);
1854 BO_UNLOCK(bo);
1855 vnode_pager_setsize(vp, length);
1856
1857 return (0);
1858 }
1859
1860 static void
1861 buf_vlist_remove(struct buf *bp)
1862 {
1863 struct bufv *bv;
1864
1865 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
1866 ASSERT_BO_WLOCKED(bp->b_bufobj);
1867 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
1868 (BX_VNDIRTY|BX_VNCLEAN),
1869 ("buf_vlist_remove: Buf %p is on two lists", bp));
1870 if (bp->b_xflags & BX_VNDIRTY)
1871 bv = &bp->b_bufobj->bo_dirty;
1872 else
1873 bv = &bp->b_bufobj->bo_clean;
1874 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
1875 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
1876 bv->bv_cnt--;
1877 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1878 }
1879
1880 /*
1881 * Add the buffer to the sorted clean or dirty block list.
1882 *
1883 * NOTE: xflags is passed as a constant, optimizing this inline function!
1884 */
1885 static void
1886 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
1887 {
1888 struct bufv *bv;
1889 struct buf *n;
1890 int error;
1891
1892 ASSERT_BO_WLOCKED(bo);
1893 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
1894 ("dead bo %p", bo));
1895 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
1896 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
1897 bp->b_xflags |= xflags;
1898 if (xflags & BX_VNDIRTY)
1899 bv = &bo->bo_dirty;
1900 else
1901 bv = &bo->bo_clean;
1902
1903 /*
1904 * Keep the list ordered. Optimize empty list insertion. Assume
1905 * we tend to grow at the tail so lookup_le should usually be cheaper
1906 * than _ge.
1907 */
1908 if (bv->bv_cnt == 0 ||
1909 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
1910 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
1911 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
1912 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
1913 else
1914 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
1915 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
1916 if (error)
1917 panic("buf_vlist_add: Preallocated nodes insufficient.");
1918 bv->bv_cnt++;
1919 }
1920
1921 /*
1922 * Look up a buffer using the buffer tries.
1923 */
1924 struct buf *
1925 gbincore(struct bufobj *bo, daddr_t lblkno)
1926 {
1927 struct buf *bp;
1928
1929 ASSERT_BO_LOCKED(bo);
1930 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
1931 if (bp != NULL)
1932 return (bp);
1933 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
1934 }
1935
1936 /*
1937 * Associate a buffer with a vnode.
1938 */
1939 void
1940 bgetvp(struct vnode *vp, struct buf *bp)
1941 {
1942 struct bufobj *bo;
1943
1944 bo = &vp->v_bufobj;
1945 ASSERT_BO_WLOCKED(bo);
1946 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
1947
1948 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
1949 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
1950 ("bgetvp: bp already attached! %p", bp));
1951
1952 vhold(vp);
1953 bp->b_vp = vp;
1954 bp->b_bufobj = bo;
1955 /*
1956 * Insert onto list for new vnode.
1957 */
1958 buf_vlist_add(bp, bo, BX_VNCLEAN);
1959 }
1960
1961 /*
1962 * Disassociate a buffer from a vnode.
1963 */
1964 void
1965 brelvp(struct buf *bp)
1966 {
1967 struct bufobj *bo;
1968 struct vnode *vp;
1969
1970 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
1971 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1972
1973 /*
1974 * Delete from old vnode list, if on one.
1975 */
1976 vp = bp->b_vp; /* XXX */
1977 bo = bp->b_bufobj;
1978 BO_LOCK(bo);
1979 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1980 buf_vlist_remove(bp);
1981 else
1982 panic("brelvp: Buffer %p not on queue.", bp);
1983 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
1984 bo->bo_flag &= ~BO_ONWORKLST;
1985 mtx_lock(&sync_mtx);
1986 LIST_REMOVE(bo, bo_synclist);
1987 syncer_worklist_len--;
1988 mtx_unlock(&sync_mtx);
1989 }
1990 bp->b_vp = NULL;
1991 bp->b_bufobj = NULL;
1992 BO_UNLOCK(bo);
1993 vdrop(vp);
1994 }
1995
1996 /*
1997 * Add an item to the syncer work queue.
1998 */
1999 static void
2000 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2001 {
2002 int slot;
2003
2004 ASSERT_BO_WLOCKED(bo);
2005
2006 mtx_lock(&sync_mtx);
2007 if (bo->bo_flag & BO_ONWORKLST)
2008 LIST_REMOVE(bo, bo_synclist);
2009 else {
2010 bo->bo_flag |= BO_ONWORKLST;
2011 syncer_worklist_len++;
2012 }
2013
2014 if (delay > syncer_maxdelay - 2)
2015 delay = syncer_maxdelay - 2;
2016 slot = (syncer_delayno + delay) & syncer_mask;
2017
2018 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2019 mtx_unlock(&sync_mtx);
2020 }
2021
2022 static int
2023 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2024 {
2025 int error, len;
2026
2027 mtx_lock(&sync_mtx);
2028 len = syncer_worklist_len - sync_vnode_count;
2029 mtx_unlock(&sync_mtx);
2030 error = SYSCTL_OUT(req, &len, sizeof(len));
2031 return (error);
2032 }
2033
2034 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
2035 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2036
2037 static struct proc *updateproc;
2038 static void sched_sync(void);
2039 static struct kproc_desc up_kp = {
2040 "syncer",
2041 sched_sync,
2042 &updateproc
2043 };
2044 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2045
2046 static int
2047 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2048 {
2049 struct vnode *vp;
2050 struct mount *mp;
2051
2052 *bo = LIST_FIRST(slp);
2053 if (*bo == NULL)
2054 return (0);
2055 vp = (*bo)->__bo_vnode; /* XXX */
2056 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2057 return (1);
2058 /*
2059 * We use vhold in case the vnode does not
2060 * successfully sync. vhold prevents the vnode from
2061 * going away when we unlock the sync_mtx so that
2062 * we can acquire the vnode interlock.
2063 */
2064 vholdl(vp);
2065 mtx_unlock(&sync_mtx);
2066 VI_UNLOCK(vp);
2067 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2068 vdrop(vp);
2069 mtx_lock(&sync_mtx);
2070 return (*bo == LIST_FIRST(slp));
2071 }
2072 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2073 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2074 VOP_UNLOCK(vp, 0);
2075 vn_finished_write(mp);
2076 BO_LOCK(*bo);
2077 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2078 /*
2079 * Put us back on the worklist. The worklist
2080 * routine will remove us from our current
2081 * position and then add us back in at a later
2082 * position.
2083 */
2084 vn_syncer_add_to_worklist(*bo, syncdelay);
2085 }
2086 BO_UNLOCK(*bo);
2087 vdrop(vp);
2088 mtx_lock(&sync_mtx);
2089 return (0);
2090 }
2091
2092 static int first_printf = 1;
2093
2094 /*
2095 * System filesystem synchronizer daemon.
2096 */
2097 static void
2098 sched_sync(void)
2099 {
2100 struct synclist *next, *slp;
2101 struct bufobj *bo;
2102 long starttime;
2103 struct thread *td = curthread;
2104 int last_work_seen;
2105 int net_worklist_len;
2106 int syncer_final_iter;
2107 int error;
2108
2109 last_work_seen = 0;
2110 syncer_final_iter = 0;
2111 syncer_state = SYNCER_RUNNING;
2112 starttime = time_uptime;
2113 td->td_pflags |= TDP_NORUNNINGBUF;
2114
2115 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
2116 SHUTDOWN_PRI_LAST);
2117
2118 mtx_lock(&sync_mtx);
2119 for (;;) {
2120 if (syncer_state == SYNCER_FINAL_DELAY &&
2121 syncer_final_iter == 0) {
2122 mtx_unlock(&sync_mtx);
2123 kproc_suspend_check(td->td_proc);
2124 mtx_lock(&sync_mtx);
2125 }
2126 net_worklist_len = syncer_worklist_len - sync_vnode_count;
2127 if (syncer_state != SYNCER_RUNNING &&
2128 starttime != time_uptime) {
2129 if (first_printf) {
2130 printf("\nSyncing disks, vnodes remaining... ");
2131 first_printf = 0;
2132 }
2133 printf("%d ", net_worklist_len);
2134 }
2135 starttime = time_uptime;
2136
2137 /*
2138 * Push files whose dirty time has expired. Be careful
2139 * of interrupt race on slp queue.
2140 *
2141 * Skip over empty worklist slots when shutting down.
2142 */
2143 do {
2144 slp = &syncer_workitem_pending[syncer_delayno];
2145 syncer_delayno += 1;
2146 if (syncer_delayno == syncer_maxdelay)
2147 syncer_delayno = 0;
2148 next = &syncer_workitem_pending[syncer_delayno];
2149 /*
2150 * If the worklist has wrapped since the
2151 * it was emptied of all but syncer vnodes,
2152 * switch to the FINAL_DELAY state and run
2153 * for one more second.
2154 */
2155 if (syncer_state == SYNCER_SHUTTING_DOWN &&
2156 net_worklist_len == 0 &&
2157 last_work_seen == syncer_delayno) {
2158 syncer_state = SYNCER_FINAL_DELAY;
2159 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
2160 }
2161 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
2162 syncer_worklist_len > 0);
2163
2164 /*
2165 * Keep track of the last time there was anything
2166 * on the worklist other than syncer vnodes.
2167 * Return to the SHUTTING_DOWN state if any
2168 * new work appears.
2169 */
2170 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
2171 last_work_seen = syncer_delayno;
2172 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
2173 syncer_state = SYNCER_SHUTTING_DOWN;
2174 while (!LIST_EMPTY(slp)) {
2175 error = sync_vnode(slp, &bo, td);
2176 if (error == 1) {
2177 LIST_REMOVE(bo, bo_synclist);
2178 LIST_INSERT_HEAD(next, bo, bo_synclist);
2179 continue;
2180 }
2181
2182 if (first_printf == 0) {
2183 /*
2184 * Drop the sync mutex, because some watchdog
2185 * drivers need to sleep while patting
2186 */
2187 mtx_unlock(&sync_mtx);
2188 wdog_kern_pat(WD_LASTVAL);
2189 mtx_lock(&sync_mtx);
2190 }
2191
2192 }
2193 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
2194 syncer_final_iter--;
2195 /*
2196 * The variable rushjob allows the kernel to speed up the
2197 * processing of the filesystem syncer process. A rushjob
2198 * value of N tells the filesystem syncer to process the next
2199 * N seconds worth of work on its queue ASAP. Currently rushjob
2200 * is used by the soft update code to speed up the filesystem
2201 * syncer process when the incore state is getting so far
2202 * ahead of the disk that the kernel memory pool is being
2203 * threatened with exhaustion.
2204 */
2205 if (rushjob > 0) {
2206 rushjob -= 1;
2207 continue;
2208 }
2209 /*
2210 * Just sleep for a short period of time between
2211 * iterations when shutting down to allow some I/O
2212 * to happen.
2213 *
2214 * If it has taken us less than a second to process the
2215 * current work, then wait. Otherwise start right over
2216 * again. We can still lose time if any single round
2217 * takes more than two seconds, but it does not really
2218 * matter as we are just trying to generally pace the
2219 * filesystem activity.
2220 */
2221 if (syncer_state != SYNCER_RUNNING ||
2222 time_uptime == starttime) {
2223 thread_lock(td);
2224 sched_prio(td, PPAUSE);
2225 thread_unlock(td);
2226 }
2227 if (syncer_state != SYNCER_RUNNING)
2228 cv_timedwait(&sync_wakeup, &sync_mtx,
2229 hz / SYNCER_SHUTDOWN_SPEEDUP);
2230 else if (time_uptime == starttime)
2231 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
2232 }
2233 }
2234
2235 /*
2236 * Request the syncer daemon to speed up its work.
2237 * We never push it to speed up more than half of its
2238 * normal turn time, otherwise it could take over the cpu.
2239 */
2240 int
2241 speedup_syncer(void)
2242 {
2243 int ret = 0;
2244
2245 mtx_lock(&sync_mtx);
2246 if (rushjob < syncdelay / 2) {
2247 rushjob += 1;
2248 stat_rush_requests += 1;
2249 ret = 1;
2250 }
2251 mtx_unlock(&sync_mtx);
2252 cv_broadcast(&sync_wakeup);
2253 return (ret);
2254 }
2255
2256 /*
2257 * Tell the syncer to speed up its work and run though its work
2258 * list several times, then tell it to shut down.
2259 */
2260 static void
2261 syncer_shutdown(void *arg, int howto)
2262 {
2263
2264 if (howto & RB_NOSYNC)
2265 return;
2266 mtx_lock(&sync_mtx);
2267 syncer_state = SYNCER_SHUTTING_DOWN;
2268 rushjob = 0;
2269 mtx_unlock(&sync_mtx);
2270 cv_broadcast(&sync_wakeup);
2271 kproc_shutdown(arg, howto);
2272 }
2273
2274 void
2275 syncer_suspend(void)
2276 {
2277
2278 syncer_shutdown(updateproc, 0);
2279 }
2280
2281 void
2282 syncer_resume(void)
2283 {
2284
2285 mtx_lock(&sync_mtx);
2286 first_printf = 1;
2287 syncer_state = SYNCER_RUNNING;
2288 mtx_unlock(&sync_mtx);
2289 cv_broadcast(&sync_wakeup);
2290 kproc_resume(updateproc);
2291 }
2292
2293 /*
2294 * Reassign a buffer from one vnode to another.
2295 * Used to assign file specific control information
2296 * (indirect blocks) to the vnode to which they belong.
2297 */
2298 void
2299 reassignbuf(struct buf *bp)
2300 {
2301 struct vnode *vp;
2302 struct bufobj *bo;
2303 int delay;
2304 #ifdef INVARIANTS
2305 struct bufv *bv;
2306 #endif
2307
2308 vp = bp->b_vp;
2309 bo = bp->b_bufobj;
2310 ++reassignbufcalls;
2311
2312 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
2313 bp, bp->b_vp, bp->b_flags);
2314 /*
2315 * B_PAGING flagged buffers cannot be reassigned because their vp
2316 * is not fully linked in.
2317 */
2318 if (bp->b_flags & B_PAGING)
2319 panic("cannot reassign paging buffer");
2320
2321 /*
2322 * Delete from old vnode list, if on one.
2323 */
2324 BO_LOCK(bo);
2325 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2326 buf_vlist_remove(bp);
2327 else
2328 panic("reassignbuf: Buffer %p not on queue.", bp);
2329 /*
2330 * If dirty, put on list of dirty buffers; otherwise insert onto list
2331 * of clean buffers.
2332 */
2333 if (bp->b_flags & B_DELWRI) {
2334 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
2335 switch (vp->v_type) {
2336 case VDIR:
2337 delay = dirdelay;
2338 break;
2339 case VCHR:
2340 delay = metadelay;
2341 break;
2342 default:
2343 delay = filedelay;
2344 }
2345 vn_syncer_add_to_worklist(bo, delay);
2346 }
2347 buf_vlist_add(bp, bo, BX_VNDIRTY);
2348 } else {
2349 buf_vlist_add(bp, bo, BX_VNCLEAN);
2350
2351 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2352 mtx_lock(&sync_mtx);
2353 LIST_REMOVE(bo, bo_synclist);
2354 syncer_worklist_len--;
2355 mtx_unlock(&sync_mtx);
2356 bo->bo_flag &= ~BO_ONWORKLST;
2357 }
2358 }
2359 #ifdef INVARIANTS
2360 bv = &bo->bo_clean;
2361 bp = TAILQ_FIRST(&bv->bv_hd);
2362 KASSERT(bp == NULL || bp->b_bufobj == bo,
2363 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2364 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2365 KASSERT(bp == NULL || bp->b_bufobj == bo,
2366 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2367 bv = &bo->bo_dirty;
2368 bp = TAILQ_FIRST(&bv->bv_hd);
2369 KASSERT(bp == NULL || bp->b_bufobj == bo,
2370 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2371 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2372 KASSERT(bp == NULL || bp->b_bufobj == bo,
2373 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2374 #endif
2375 BO_UNLOCK(bo);
2376 }
2377
2378 /*
2379 * A temporary hack until refcount_* APIs are sorted out.
2380 */
2381 static __inline int
2382 vfs_refcount_acquire_if_not_zero(volatile u_int *count)
2383 {
2384 u_int old;
2385
2386 for (;;) {
2387 old = *count;
2388 if (old == 0)
2389 return (0);
2390 if (atomic_cmpset_int(count, old, old + 1))
2391 return (1);
2392 }
2393 }
2394
2395 static __inline int
2396 vfs_refcount_release_if_not_last(volatile u_int *count)
2397 {
2398 u_int old;
2399
2400 for (;;) {
2401 old = *count;
2402 if (old == 1)
2403 return (0);
2404 if (atomic_cmpset_int(count, old, old - 1))
2405 return (1);
2406 }
2407 }
2408
2409 static void
2410 v_init_counters(struct vnode *vp)
2411 {
2412
2413 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
2414 vp, ("%s called for an initialized vnode", __FUNCTION__));
2415 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
2416
2417 refcount_init(&vp->v_holdcnt, 1);
2418 refcount_init(&vp->v_usecount, 1);
2419 }
2420
2421 static void
2422 v_incr_usecount_locked(struct vnode *vp)
2423 {
2424
2425 ASSERT_VI_LOCKED(vp, __func__);
2426 if ((vp->v_iflag & VI_OWEINACT) != 0) {
2427 VNASSERT(vp->v_usecount == 0, vp,
2428 ("vnode with usecount and VI_OWEINACT set"));
2429 vp->v_iflag &= ~VI_OWEINACT;
2430 }
2431 refcount_acquire(&vp->v_usecount);
2432 v_incr_devcount(vp);
2433 }
2434
2435 /*
2436 * Increment the use and hold counts on the vnode, taking care to reference
2437 * the driver's usecount if this is a chardev. The _vhold() will remove
2438 * the vnode from the free list if it is presently free.
2439 */
2440 static void
2441 v_incr_usecount(struct vnode *vp)
2442 {
2443
2444 ASSERT_VI_UNLOCKED(vp, __func__);
2445 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2446
2447 if (vp->v_type != VCHR &&
2448 vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) {
2449 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2450 ("vnode with usecount and VI_OWEINACT set"));
2451 } else {
2452 VI_LOCK(vp);
2453 v_incr_usecount_locked(vp);
2454 VI_UNLOCK(vp);
2455 }
2456 }
2457
2458 /*
2459 * Increment si_usecount of the associated device, if any.
2460 */
2461 static void
2462 v_incr_devcount(struct vnode *vp)
2463 {
2464
2465 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2466 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2467 dev_lock();
2468 vp->v_rdev->si_usecount++;
2469 dev_unlock();
2470 }
2471 }
2472
2473 /*
2474 * Decrement si_usecount of the associated device, if any.
2475 */
2476 static void
2477 v_decr_devcount(struct vnode *vp)
2478 {
2479
2480 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2481 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2482 dev_lock();
2483 vp->v_rdev->si_usecount--;
2484 dev_unlock();
2485 }
2486 }
2487
2488 /*
2489 * Grab a particular vnode from the free list, increment its
2490 * reference count and lock it. VI_DOOMED is set if the vnode
2491 * is being destroyed. Only callers who specify LK_RETRY will
2492 * see doomed vnodes. If inactive processing was delayed in
2493 * vput try to do it here.
2494 *
2495 * Notes on lockless counter manipulation:
2496 * _vhold, vputx and other routines make various decisions based
2497 * on either holdcnt or usecount being 0. As long as either counter
2498 * is not transitioning 0->1 nor 1->0, the manipulation can be done
2499 * with atomic operations. Otherwise the interlock is taken covering
2500 * both the atomic and additional actions.
2501 */
2502 int
2503 vget(struct vnode *vp, int flags, struct thread *td)
2504 {
2505 int error, oweinact;
2506
2507 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2508 ("vget: invalid lock operation"));
2509
2510 if ((flags & LK_INTERLOCK) != 0)
2511 ASSERT_VI_LOCKED(vp, __func__);
2512 else
2513 ASSERT_VI_UNLOCKED(vp, __func__);
2514 if ((flags & LK_VNHELD) != 0)
2515 VNASSERT((vp->v_holdcnt > 0), vp,
2516 ("vget: LK_VNHELD passed but vnode not held"));
2517
2518 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
2519
2520 if ((flags & LK_VNHELD) == 0)
2521 _vhold(vp, (flags & LK_INTERLOCK) != 0);
2522
2523 if ((error = vn_lock(vp, flags)) != 0) {
2524 vdrop(vp);
2525 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2526 vp);
2527 return (error);
2528 }
2529 if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
2530 panic("vget: vn_lock failed to return ENOENT\n");
2531 /*
2532 * We don't guarantee that any particular close will
2533 * trigger inactive processing so just make a best effort
2534 * here at preventing a reference to a removed file. If
2535 * we don't succeed no harm is done.
2536 *
2537 * Upgrade our holdcnt to a usecount.
2538 */
2539 if (vp->v_type == VCHR ||
2540 !vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) {
2541 VI_LOCK(vp);
2542 if ((vp->v_iflag & VI_OWEINACT) == 0) {
2543 oweinact = 0;
2544 } else {
2545 oweinact = 1;
2546 vp->v_iflag &= ~VI_OWEINACT;
2547 }
2548 refcount_acquire(&vp->v_usecount);
2549 v_incr_devcount(vp);
2550 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2551 (flags & LK_NOWAIT) == 0)
2552 vinactive(vp, td);
2553 VI_UNLOCK(vp);
2554 }
2555 return (0);
2556 }
2557
2558 /*
2559 * Increase the reference count of a vnode.
2560 */
2561 void
2562 vref(struct vnode *vp)
2563 {
2564
2565 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2566 _vhold(vp, false);
2567 v_incr_usecount(vp);
2568 }
2569
2570 void
2571 vrefl(struct vnode *vp)
2572 {
2573
2574 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2575 _vhold(vp, true);
2576 v_incr_usecount_locked(vp);
2577 }
2578
2579 /*
2580 * Return reference count of a vnode.
2581 *
2582 * The results of this call are only guaranteed when some mechanism is used to
2583 * stop other processes from gaining references to the vnode. This may be the
2584 * case if the caller holds the only reference. This is also useful when stale
2585 * data is acceptable as race conditions may be accounted for by some other
2586 * means.
2587 */
2588 int
2589 vrefcnt(struct vnode *vp)
2590 {
2591
2592 return (vp->v_usecount);
2593 }
2594
2595 #define VPUTX_VRELE 1
2596 #define VPUTX_VPUT 2
2597 #define VPUTX_VUNREF 3
2598
2599 /*
2600 * Decrement the use and hold counts for a vnode.
2601 *
2602 * See an explanation near vget() as to why atomic operation is safe.
2603 */
2604 static void
2605 vputx(struct vnode *vp, int func)
2606 {
2607 int error;
2608
2609 KASSERT(vp != NULL, ("vputx: null vp"));
2610 if (func == VPUTX_VUNREF)
2611 ASSERT_VOP_LOCKED(vp, "vunref");
2612 else if (func == VPUTX_VPUT)
2613 ASSERT_VOP_LOCKED(vp, "vput");
2614 else
2615 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2616 ASSERT_VI_UNLOCKED(vp, __func__);
2617 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2618
2619 if (vp->v_type != VCHR &&
2620 vfs_refcount_release_if_not_last(&vp->v_usecount)) {
2621 if (func == VPUTX_VPUT)
2622 VOP_UNLOCK(vp, 0);
2623 vdrop(vp);
2624 return;
2625 }
2626
2627 VI_LOCK(vp);
2628
2629 /*
2630 * We want to hold the vnode until the inactive finishes to
2631 * prevent vgone() races. We drop the use count here and the
2632 * hold count below when we're done.
2633 */
2634 if (!refcount_release(&vp->v_usecount) ||
2635 (vp->v_iflag & VI_DOINGINACT)) {
2636 if (func == VPUTX_VPUT)
2637 VOP_UNLOCK(vp, 0);
2638 v_decr_devcount(vp);
2639 vdropl(vp);
2640 return;
2641 }
2642
2643 v_decr_devcount(vp);
2644
2645 error = 0;
2646
2647 if (vp->v_usecount != 0) {
2648 vprint("vputx: usecount not zero", vp);
2649 panic("vputx: usecount not zero");
2650 }
2651
2652 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
2653
2654 /*
2655 * We must call VOP_INACTIVE with the node locked. Mark
2656 * as VI_DOINGINACT to avoid recursion.
2657 */
2658 vp->v_iflag |= VI_OWEINACT;
2659 switch (func) {
2660 case VPUTX_VRELE:
2661 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
2662 VI_LOCK(vp);
2663 break;
2664 case VPUTX_VPUT:
2665 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2666 error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
2667 LK_NOWAIT);
2668 VI_LOCK(vp);
2669 }
2670 break;
2671 case VPUTX_VUNREF:
2672 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
2673 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
2674 VI_LOCK(vp);
2675 }
2676 break;
2677 }
2678 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp,
2679 ("vnode with usecount and VI_OWEINACT set"));
2680 if (error == 0) {
2681 if (vp->v_iflag & VI_OWEINACT)
2682 vinactive(vp, curthread);
2683 if (func != VPUTX_VUNREF)
2684 VOP_UNLOCK(vp, 0);
2685 }
2686 vdropl(vp);
2687 }
2688
2689 /*
2690 * Vnode put/release.
2691 * If count drops to zero, call inactive routine and return to freelist.
2692 */
2693 void
2694 vrele(struct vnode *vp)
2695 {
2696
2697 vputx(vp, VPUTX_VRELE);
2698 }
2699
2700 /*
2701 * Release an already locked vnode. This give the same effects as
2702 * unlock+vrele(), but takes less time and avoids releasing and
2703 * re-aquiring the lock (as vrele() acquires the lock internally.)
2704 */
2705 void
2706 vput(struct vnode *vp)
2707 {
2708
2709 vputx(vp, VPUTX_VPUT);
2710 }
2711
2712 /*
2713 * Release an exclusively locked vnode. Do not unlock the vnode lock.
2714 */
2715 void
2716 vunref(struct vnode *vp)
2717 {
2718
2719 vputx(vp, VPUTX_VUNREF);
2720 }
2721
2722 /*
2723 * Increase the hold count and activate if this is the first reference.
2724 */
2725 void
2726 _vhold(struct vnode *vp, bool locked)
2727 {
2728 struct mount *mp;
2729
2730 if (locked)
2731 ASSERT_VI_LOCKED(vp, __func__);
2732 else
2733 ASSERT_VI_UNLOCKED(vp, __func__);
2734 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2735 if (!locked && vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) {
2736 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2737 ("_vhold: vnode with holdcnt is free"));
2738 return;
2739 }
2740
2741 if (!locked)
2742 VI_LOCK(vp);
2743 if ((vp->v_iflag & VI_FREE) == 0) {
2744 refcount_acquire(&vp->v_holdcnt);
2745 if (!locked)
2746 VI_UNLOCK(vp);
2747 return;
2748 }
2749 VNASSERT(vp->v_holdcnt == 0, vp,
2750 ("%s: wrong hold count", __func__));
2751 VNASSERT(vp->v_op != NULL, vp,
2752 ("%s: vnode already reclaimed.", __func__));
2753 /*
2754 * Remove a vnode from the free list, mark it as in use,
2755 * and put it on the active list.
2756 */
2757 mtx_lock(&vnode_free_list_mtx);
2758 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
2759 freevnodes--;
2760 vp->v_iflag &= ~VI_FREE;
2761 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
2762 ("Activating already active vnode"));
2763 vp->v_iflag |= VI_ACTIVE;
2764 mp = vp->v_mount;
2765 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
2766 mp->mnt_activevnodelistsize++;
2767 mtx_unlock(&vnode_free_list_mtx);
2768 refcount_acquire(&vp->v_holdcnt);
2769 if (!locked)
2770 VI_UNLOCK(vp);
2771 }
2772
2773 /*
2774 * Drop the hold count of the vnode. If this is the last reference to
2775 * the vnode we place it on the free list unless it has been vgone'd
2776 * (marked VI_DOOMED) in which case we will free it.
2777 *
2778 * Because the vnode vm object keeps a hold reference on the vnode if
2779 * there is at least one resident non-cached page, the vnode cannot
2780 * leave the active list without the page cleanup done.
2781 */
2782 void
2783 _vdrop(struct vnode *vp, bool locked)
2784 {
2785 struct bufobj *bo;
2786 struct mount *mp;
2787 int active;
2788
2789 if (locked)
2790 ASSERT_VI_LOCKED(vp, __func__);
2791 else
2792 ASSERT_VI_UNLOCKED(vp, __func__);
2793 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2794 if ((int)vp->v_holdcnt <= 0)
2795 panic("vdrop: holdcnt %d", vp->v_holdcnt);
2796 if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) {
2797 if (locked)
2798 VI_UNLOCK(vp);
2799 return;
2800 }
2801
2802 if (!locked)
2803 VI_LOCK(vp);
2804 if (refcount_release(&vp->v_holdcnt) == 0) {
2805 VI_UNLOCK(vp);
2806 return;
2807 }
2808 if ((vp->v_iflag & VI_DOOMED) == 0) {
2809 /*
2810 * Mark a vnode as free: remove it from its active list
2811 * and put it up for recycling on the freelist.
2812 */
2813 VNASSERT(vp->v_op != NULL, vp,
2814 ("vdropl: vnode already reclaimed."));
2815 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2816 ("vnode already free"));
2817 VNASSERT(vp->v_holdcnt == 0, vp,
2818 ("vdropl: freeing when we shouldn't"));
2819 active = vp->v_iflag & VI_ACTIVE;
2820 if ((vp->v_iflag & VI_OWEINACT) == 0) {
2821 vp->v_iflag &= ~VI_ACTIVE;
2822 mp = vp->v_mount;
2823 mtx_lock(&vnode_free_list_mtx);
2824 if (active) {
2825 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp,
2826 v_actfreelist);
2827 mp->mnt_activevnodelistsize--;
2828 }
2829 TAILQ_INSERT_TAIL(&vnode_free_list, vp,
2830 v_actfreelist);
2831 freevnodes++;
2832 vp->v_iflag |= VI_FREE;
2833 mtx_unlock(&vnode_free_list_mtx);
2834 } else {
2835 atomic_add_long(&free_owe_inact, 1);
2836 }
2837 VI_UNLOCK(vp);
2838 return;
2839 }
2840 /*
2841 * The vnode has been marked for destruction, so free it.
2842 *
2843 * The vnode will be returned to the zone where it will
2844 * normally remain until it is needed for another vnode. We
2845 * need to cleanup (or verify that the cleanup has already
2846 * been done) any residual data left from its current use
2847 * so as not to contaminate the freshly allocated vnode.
2848 */
2849 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
2850 atomic_subtract_long(&numvnodes, 1);
2851 bo = &vp->v_bufobj;
2852 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
2853 ("cleaned vnode still on the free list."));
2854 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
2855 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
2856 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
2857 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
2858 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
2859 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
2860 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
2861 ("clean blk trie not empty"));
2862 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
2863 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
2864 ("dirty blk trie not empty"));
2865 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
2866 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
2867 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
2868 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp,
2869 ("Dangling rangelock waiters"));
2870 VI_UNLOCK(vp);
2871 #ifdef MAC
2872 mac_vnode_destroy(vp);
2873 #endif
2874 if (vp->v_pollinfo != NULL) {
2875 destroy_vpollinfo(vp->v_pollinfo);
2876 vp->v_pollinfo = NULL;
2877 }
2878 #ifdef INVARIANTS
2879 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
2880 vp->v_op = NULL;
2881 #endif
2882 bzero(&vp->v_un, sizeof(vp->v_un));
2883 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
2884 vp->v_iflag = 0;
2885 vp->v_vflag = 0;
2886 bo->bo_flag = 0;
2887 uma_zfree(vnode_zone, vp);
2888 }
2889
2890 /*
2891 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
2892 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
2893 * OWEINACT tracks whether a vnode missed a call to inactive due to a
2894 * failed lock upgrade.
2895 */
2896 void
2897 vinactive(struct vnode *vp, struct thread *td)
2898 {
2899 struct vm_object *obj;
2900
2901 ASSERT_VOP_ELOCKED(vp, "vinactive");
2902 ASSERT_VI_LOCKED(vp, "vinactive");
2903 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
2904 ("vinactive: recursed on VI_DOINGINACT"));
2905 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2906 vp->v_iflag |= VI_DOINGINACT;
2907 vp->v_iflag &= ~VI_OWEINACT;
2908 VI_UNLOCK(vp);
2909 /*
2910 * Before moving off the active list, we must be sure that any
2911 * modified pages are converted into the vnode's dirty
2912 * buffers, since these will no longer be checked once the
2913 * vnode is on the inactive list.
2914 *
2915 * The write-out of the dirty pages is asynchronous. At the
2916 * point that VOP_INACTIVE() is called, there could still be
2917 * pending I/O and dirty pages in the object.
2918 */
2919 obj = vp->v_object;
2920 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
2921 VM_OBJECT_WLOCK(obj);
2922 vm_object_page_clean(obj, 0, 0, OBJPC_NOSYNC);
2923 VM_OBJECT_WUNLOCK(obj);
2924 }
2925 VOP_INACTIVE(vp, td);
2926 VI_LOCK(vp);
2927 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
2928 ("vinactive: lost VI_DOINGINACT"));
2929 vp->v_iflag &= ~VI_DOINGINACT;
2930 }
2931
2932 /*
2933 * Remove any vnodes in the vnode table belonging to mount point mp.
2934 *
2935 * If FORCECLOSE is not specified, there should not be any active ones,
2936 * return error if any are found (nb: this is a user error, not a
2937 * system error). If FORCECLOSE is specified, detach any active vnodes
2938 * that are found.
2939 *
2940 * If WRITECLOSE is set, only flush out regular file vnodes open for
2941 * writing.
2942 *
2943 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
2944 *
2945 * `rootrefs' specifies the base reference count for the root vnode
2946 * of this filesystem. The root vnode is considered busy if its
2947 * v_usecount exceeds this value. On a successful return, vflush(, td)
2948 * will call vrele() on the root vnode exactly rootrefs times.
2949 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
2950 * be zero.
2951 */
2952 #ifdef DIAGNOSTIC
2953 static int busyprt = 0; /* print out busy vnodes */
2954 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
2955 #endif
2956
2957 int
2958 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
2959 {
2960 struct vnode *vp, *mvp, *rootvp = NULL;
2961 struct vattr vattr;
2962 int busy = 0, error;
2963
2964 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
2965 rootrefs, flags);
2966 if (rootrefs > 0) {
2967 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
2968 ("vflush: bad args"));
2969 /*
2970 * Get the filesystem root vnode. We can vput() it
2971 * immediately, since with rootrefs > 0, it won't go away.
2972 */
2973 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
2974 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
2975 __func__, error);
2976 return (error);
2977 }
2978 vput(rootvp);
2979 }
2980 loop:
2981 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
2982 vholdl(vp);
2983 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
2984 if (error) {
2985 vdrop(vp);
2986 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
2987 goto loop;
2988 }
2989 /*
2990 * Skip over a vnodes marked VV_SYSTEM.
2991 */
2992 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
2993 VOP_UNLOCK(vp, 0);
2994 vdrop(vp);
2995 continue;
2996 }
2997 /*
2998 * If WRITECLOSE is set, flush out unlinked but still open
2999 * files (even if open only for reading) and regular file
3000 * vnodes open for writing.
3001 */
3002 if (flags & WRITECLOSE) {
3003 if (vp->v_object != NULL) {
3004 VM_OBJECT_WLOCK(vp->v_object);
3005 vm_object_page_clean(vp->v_object, 0, 0, 0);
3006 VM_OBJECT_WUNLOCK(vp->v_object);
3007 }
3008 error = VOP_FSYNC(vp, MNT_WAIT, td);
3009 if (error != 0) {
3010 VOP_UNLOCK(vp, 0);
3011 vdrop(vp);
3012 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
3013 return (error);
3014 }
3015 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
3016 VI_LOCK(vp);
3017
3018 if ((vp->v_type == VNON ||
3019 (error == 0 && vattr.va_nlink > 0)) &&
3020 (vp->v_writecount == 0 || vp->v_type != VREG)) {
3021 VOP_UNLOCK(vp, 0);
3022 vdropl(vp);
3023 continue;
3024 }
3025 } else
3026 VI_LOCK(vp);
3027 /*
3028 * With v_usecount == 0, all we need to do is clear out the
3029 * vnode data structures and we are done.
3030 *
3031 * If FORCECLOSE is set, forcibly close the vnode.
3032 */
3033 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
3034 vgonel(vp);
3035 } else {
3036 busy++;
3037 #ifdef DIAGNOSTIC
3038 if (busyprt)
3039 vprint("vflush: busy vnode", vp);
3040 #endif
3041 }
3042 VOP_UNLOCK(vp, 0);
3043 vdropl(vp);
3044 }
3045 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
3046 /*
3047 * If just the root vnode is busy, and if its refcount
3048 * is equal to `rootrefs', then go ahead and kill it.
3049 */
3050 VI_LOCK(rootvp);
3051 KASSERT(busy > 0, ("vflush: not busy"));
3052 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
3053 ("vflush: usecount %d < rootrefs %d",
3054 rootvp->v_usecount, rootrefs));
3055 if (busy == 1 && rootvp->v_usecount == rootrefs) {
3056 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
3057 vgone(rootvp);
3058 VOP_UNLOCK(rootvp, 0);
3059 busy = 0;
3060 } else
3061 VI_UNLOCK(rootvp);
3062 }
3063 if (busy) {
3064 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
3065 busy);
3066 return (EBUSY);
3067 }
3068 for (; rootrefs > 0; rootrefs--)
3069 vrele(rootvp);
3070 return (0);
3071 }
3072
3073 /*
3074 * Recycle an unused vnode to the front of the free list.
3075 */
3076 int
3077 vrecycle(struct vnode *vp)
3078 {
3079 int recycled;
3080
3081 ASSERT_VOP_ELOCKED(vp, "vrecycle");
3082 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3083 recycled = 0;
3084 VI_LOCK(vp);
3085 if (vp->v_usecount == 0) {
3086 recycled = 1;
3087 vgonel(vp);
3088 }
3089 VI_UNLOCK(vp);
3090 return (recycled);
3091 }
3092
3093 /*
3094 * Eliminate all activity associated with a vnode
3095 * in preparation for reuse.
3096 */
3097 void
3098 vgone(struct vnode *vp)
3099 {
3100 VI_LOCK(vp);
3101 vgonel(vp);
3102 VI_UNLOCK(vp);
3103 }
3104
3105 static void
3106 notify_lowervp_vfs_dummy(struct mount *mp __unused,
3107 struct vnode *lowervp __unused)
3108 {
3109 }
3110
3111 /*
3112 * Notify upper mounts about reclaimed or unlinked vnode.
3113 */
3114 void
3115 vfs_notify_upper(struct vnode *vp, int event)
3116 {
3117 static struct vfsops vgonel_vfsops = {
3118 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy,
3119 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy,
3120 };
3121 struct mount *mp, *ump, *mmp;
3122
3123 mp = vp->v_mount;
3124 if (mp == NULL)
3125 return;
3126
3127 MNT_ILOCK(mp);
3128 if (TAILQ_EMPTY(&mp->mnt_uppers))
3129 goto unlock;
3130 MNT_IUNLOCK(mp);
3131 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO);
3132 mmp->mnt_op = &vgonel_vfsops;
3133 mmp->mnt_kern_flag |= MNTK_MARKER;
3134 MNT_ILOCK(mp);
3135 mp->mnt_kern_flag |= MNTK_VGONE_UPPER;
3136 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) {
3137 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) {
3138 ump = TAILQ_NEXT(ump, mnt_upper_link);
3139 continue;
3140 }
3141 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link);
3142 MNT_IUNLOCK(mp);
3143 switch (event) {
3144 case VFS_NOTIFY_UPPER_RECLAIM:
3145 VFS_RECLAIM_LOWERVP(ump, vp);
3146 break;
3147 case VFS_NOTIFY_UPPER_UNLINK:
3148 VFS_UNLINK_LOWERVP(ump, vp);
3149 break;
3150 default:
3151 KASSERT(0, ("invalid event %d", event));
3152 break;
3153 }
3154 MNT_ILOCK(mp);
3155 ump = TAILQ_NEXT(mmp, mnt_upper_link);
3156 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link);
3157 }
3158 free(mmp, M_TEMP);
3159 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER;
3160 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) {
3161 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER;
3162 wakeup(&mp->mnt_uppers);
3163 }
3164 unlock:
3165 MNT_IUNLOCK(mp);
3166 }
3167
3168 /*
3169 * vgone, with the vp interlock held.
3170 */
3171 static void
3172 vgonel(struct vnode *vp)
3173 {
3174 struct thread *td;
3175 int oweinact;
3176 int active;
3177 struct mount *mp;
3178
3179 ASSERT_VOP_ELOCKED(vp, "vgonel");
3180 ASSERT_VI_LOCKED(vp, "vgonel");
3181 VNASSERT(vp->v_holdcnt, vp,
3182 ("vgonel: vp %p has no reference.", vp));
3183 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3184 td = curthread;
3185
3186 /*
3187 * Don't vgonel if we're already doomed.
3188 */
3189 if (vp->v_iflag & VI_DOOMED)
3190 return;
3191 vp->v_iflag |= VI_DOOMED;
3192
3193 /*
3194 * Check to see if the vnode is in use. If so, we have to call
3195 * VOP_CLOSE() and VOP_INACTIVE().
3196 */
3197 active = vp->v_usecount;
3198 oweinact = (vp->v_iflag & VI_OWEINACT);
3199 VI_UNLOCK(vp);
3200 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
3201
3202 /*
3203 * If purging an active vnode, it must be closed and
3204 * deactivated before being reclaimed.
3205 */
3206 if (active)
3207 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
3208 if (oweinact || active) {
3209 VI_LOCK(vp);
3210 if ((vp->v_iflag & VI_DOINGINACT) == 0)
3211 vinactive(vp, td);
3212 VI_UNLOCK(vp);
3213 }
3214 if (vp->v_type == VSOCK)
3215 vfs_unp_reclaim(vp);
3216
3217 /*
3218 * Clean out any buffers associated with the vnode.
3219 * If the flush fails, just toss the buffers.
3220 */
3221 mp = NULL;
3222 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
3223 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
3224 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
3225 while (vinvalbuf(vp, 0, 0, 0) != 0)
3226 ;
3227 }
3228
3229 BO_LOCK(&vp->v_bufobj);
3230 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
3231 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
3232 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
3233 vp->v_bufobj.bo_clean.bv_cnt == 0,
3234 ("vp %p bufobj not invalidated", vp));
3235
3236 /*
3237 * For VMIO bufobj, BO_DEAD is set in vm_object_terminate()
3238 * after the object's page queue is flushed.
3239 */
3240 if (vp->v_bufobj.bo_object == NULL)
3241 vp->v_bufobj.bo_flag |= BO_DEAD;
3242 BO_UNLOCK(&vp->v_bufobj);
3243
3244 /*
3245 * Reclaim the vnode.
3246 */
3247 if (VOP_RECLAIM(vp, td))
3248 panic("vgone: cannot reclaim");
3249 if (mp != NULL)
3250 vn_finished_secondary_write(mp);
3251 VNASSERT(vp->v_object == NULL, vp,
3252 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
3253 /*
3254 * Clear the advisory locks and wake up waiting threads.
3255 */
3256 (void)VOP_ADVLOCKPURGE(vp);
3257 vp->v_lockf = NULL;
3258 /*
3259 * Delete from old mount point vnode list.
3260 */
3261 delmntque(vp);
3262 cache_purge(vp);
3263 /*
3264 * Done with purge, reset to the standard lock and invalidate
3265 * the vnode.
3266 */
3267 VI_LOCK(vp);
3268 vp->v_vnlock = &vp->v_lock;
3269 vp->v_op = &dead_vnodeops;
3270 vp->v_tag = "none";
3271 vp->v_type = VBAD;
3272 }
3273
3274 /*
3275 * Calculate the total number of references to a special device.
3276 */
3277 int
3278 vcount(struct vnode *vp)
3279 {
3280 int count;
3281
3282 dev_lock();
3283 count = vp->v_rdev->si_usecount;
3284 dev_unlock();
3285 return (count);
3286 }
3287
3288 /*
3289 * Same as above, but using the struct cdev *as argument
3290 */
3291 int
3292 count_dev(struct cdev *dev)
3293 {
3294 int count;
3295
3296 dev_lock();
3297 count = dev->si_usecount;
3298 dev_unlock();
3299 return(count);
3300 }
3301
3302 /*
3303 * Print out a description of a vnode.
3304 */
3305 static char *typename[] =
3306 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
3307 "VMARKER"};
3308
3309 void
3310 vn_printf(struct vnode *vp, const char *fmt, ...)
3311 {
3312 va_list ap;
3313 char buf[256], buf2[16];
3314 u_long flags;
3315
3316 va_start(ap, fmt);
3317 vprintf(fmt, ap);
3318 va_end(ap);
3319 printf("%p: ", (void *)vp);
3320 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
3321 printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
3322 vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
3323 buf[0] = '\0';
3324 buf[1] = '\0';
3325 if (vp->v_vflag & VV_ROOT)
3326 strlcat(buf, "|VV_ROOT", sizeof(buf));
3327 if (vp->v_vflag & VV_ISTTY)
3328 strlcat(buf, "|VV_ISTTY", sizeof(buf));
3329 if (vp->v_vflag & VV_NOSYNC)
3330 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
3331 if (vp->v_vflag & VV_ETERNALDEV)
3332 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
3333 if (vp->v_vflag & VV_CACHEDLABEL)
3334 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
3335 if (vp->v_vflag & VV_TEXT)
3336 strlcat(buf, "|VV_TEXT", sizeof(buf));
3337 if (vp->v_vflag & VV_COPYONWRITE)
3338 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
3339 if (vp->v_vflag & VV_SYSTEM)
3340 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
3341 if (vp->v_vflag & VV_PROCDEP)
3342 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
3343 if (vp->v_vflag & VV_NOKNOTE)
3344 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
3345 if (vp->v_vflag & VV_DELETED)
3346 strlcat(buf, "|VV_DELETED", sizeof(buf));
3347 if (vp->v_vflag & VV_MD)
3348 strlcat(buf, "|VV_MD", sizeof(buf));
3349 if (vp->v_vflag & VV_FORCEINSMQ)
3350 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
3351 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
3352 VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
3353 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ);
3354 if (flags != 0) {
3355 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
3356 strlcat(buf, buf2, sizeof(buf));
3357 }
3358 if (vp->v_iflag & VI_MOUNT)
3359 strlcat(buf, "|VI_MOUNT", sizeof(buf));
3360 if (vp->v_iflag & VI_DOOMED)
3361 strlcat(buf, "|VI_DOOMED", sizeof(buf));
3362 if (vp->v_iflag & VI_FREE)
3363 strlcat(buf, "|VI_FREE", sizeof(buf));
3364 if (vp->v_iflag & VI_ACTIVE)
3365 strlcat(buf, "|VI_ACTIVE", sizeof(buf));
3366 if (vp->v_iflag & VI_DOINGINACT)
3367 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
3368 if (vp->v_iflag & VI_OWEINACT)
3369 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
3370 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE |
3371 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT);
3372 if (flags != 0) {
3373 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
3374 strlcat(buf, buf2, sizeof(buf));
3375 }
3376 printf(" flags (%s)\n", buf + 1);
3377 if (mtx_owned(VI_MTX(vp)))
3378 printf(" VI_LOCKed");
3379 if (vp->v_object != NULL)
3380 printf(" v_object %p ref %d pages %d "
3381 "cleanbuf %d dirtybuf %d\n",
3382 vp->v_object, vp->v_object->ref_count,
3383 vp->v_object->resident_page_count,
3384 vp->v_bufobj.bo_clean.bv_cnt,
3385 vp->v_bufobj.bo_dirty.bv_cnt);
3386 printf(" ");
3387 lockmgr_printinfo(vp->v_vnlock);
3388 if (vp->v_data != NULL)
3389 VOP_PRINT(vp);
3390 }
3391
3392 #ifdef DDB
3393 /*
3394 * List all of the locked vnodes in the system.
3395 * Called when debugging the kernel.
3396 */
3397 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
3398 {
3399 struct mount *mp;
3400 struct vnode *vp;
3401
3402 /*
3403 * Note: because this is DDB, we can't obey the locking semantics
3404 * for these structures, which means we could catch an inconsistent
3405 * state and dereference a nasty pointer. Not much to be done
3406 * about that.
3407 */
3408 db_printf("Locked vnodes\n");
3409 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3410 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3411 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
3412 vprint("", vp);
3413 }
3414 }
3415 }
3416
3417 /*
3418 * Show details about the given vnode.
3419 */
3420 DB_SHOW_COMMAND(vnode, db_show_vnode)
3421 {
3422 struct vnode *vp;
3423
3424 if (!have_addr)
3425 return;
3426 vp = (struct vnode *)addr;
3427 vn_printf(vp, "vnode ");
3428 }
3429
3430 /*
3431 * Show details about the given mount point.
3432 */
3433 DB_SHOW_COMMAND(mount, db_show_mount)
3434 {
3435 struct mount *mp;
3436 struct vfsopt *opt;
3437 struct statfs *sp;
3438 struct vnode *vp;
3439 char buf[512];
3440 uint64_t mflags;
3441 u_int flags;
3442
3443 if (!have_addr) {
3444 /* No address given, print short info about all mount points. */
3445 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3446 db_printf("%p %s on %s (%s)\n", mp,
3447 mp->mnt_stat.f_mntfromname,
3448 mp->mnt_stat.f_mntonname,
3449 mp->mnt_stat.f_fstypename);
3450 if (db_pager_quit)
3451 break;
3452 }
3453 db_printf("\nMore info: show mount <addr>\n");
3454 return;
3455 }
3456
3457 mp = (struct mount *)addr;
3458 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
3459 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
3460
3461 buf[0] = '\0';
3462 mflags = mp->mnt_flag;
3463 #define MNT_FLAG(flag) do { \
3464 if (mflags & (flag)) { \
3465 if (buf[0] != '\0') \
3466 strlcat(buf, ", ", sizeof(buf)); \
3467 strlcat(buf, (#flag) + 4, sizeof(buf)); \
3468 mflags &= ~(flag); \
3469 } \
3470 } while (0)
3471 MNT_FLAG(MNT_RDONLY);
3472 MNT_FLAG(MNT_SYNCHRONOUS);
3473 MNT_FLAG(MNT_NOEXEC);
3474 MNT_FLAG(MNT_NOSUID);
3475 MNT_FLAG(MNT_NFS4ACLS);
3476 MNT_FLAG(MNT_UNION);
3477 MNT_FLAG(MNT_ASYNC);
3478 MNT_FLAG(MNT_SUIDDIR);
3479 MNT_FLAG(MNT_SOFTDEP);
3480 MNT_FLAG(MNT_NOSYMFOLLOW);
3481 MNT_FLAG(MNT_GJOURNAL);
3482 MNT_FLAG(MNT_MULTILABEL);
3483 MNT_FLAG(MNT_ACLS);
3484 MNT_FLAG(MNT_NOATIME);
3485 MNT_FLAG(MNT_NOCLUSTERR);
3486 MNT_FLAG(MNT_NOCLUSTERW);
3487 MNT_FLAG(MNT_SUJ);
3488 MNT_FLAG(MNT_EXRDONLY);
3489 MNT_FLAG(MNT_EXPORTED);
3490 MNT_FLAG(MNT_DEFEXPORTED);
3491 MNT_FLAG(MNT_EXPORTANON);
3492 MNT_FLAG(MNT_EXKERB);
3493 MNT_FLAG(MNT_EXPUBLIC);
3494 MNT_FLAG(MNT_LOCAL);
3495 MNT_FLAG(MNT_QUOTA);
3496 MNT_FLAG(MNT_ROOTFS);
3497 MNT_FLAG(MNT_USER);
3498 MNT_FLAG(MNT_IGNORE);
3499 MNT_FLAG(MNT_UPDATE);
3500 MNT_FLAG(MNT_DELEXPORT);
3501 MNT_FLAG(MNT_RELOAD);
3502 MNT_FLAG(MNT_FORCE);
3503 MNT_FLAG(MNT_SNAPSHOT);
3504 MNT_FLAG(MNT_BYFSID);
3505 #undef MNT_FLAG
3506 if (mflags != 0) {
3507 if (buf[0] != '\0')
3508 strlcat(buf, ", ", sizeof(buf));
3509 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3510 "0x%016jx", mflags);
3511 }
3512 db_printf(" mnt_flag = %s\n", buf);
3513
3514 buf[0] = '\0';
3515 flags = mp->mnt_kern_flag;
3516 #define MNT_KERN_FLAG(flag) do { \
3517 if (flags & (flag)) { \
3518 if (buf[0] != '\0') \
3519 strlcat(buf, ", ", sizeof(buf)); \
3520 strlcat(buf, (#flag) + 5, sizeof(buf)); \
3521 flags &= ~(flag); \
3522 } \
3523 } while (0)
3524 MNT_KERN_FLAG(MNTK_UNMOUNTF);
3525 MNT_KERN_FLAG(MNTK_ASYNC);
3526 MNT_KERN_FLAG(MNTK_SOFTDEP);
3527 MNT_KERN_FLAG(MNTK_NOINSMNTQ);
3528 MNT_KERN_FLAG(MNTK_DRAINING);
3529 MNT_KERN_FLAG(MNTK_REFEXPIRE);
3530 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
3531 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
3532 MNT_KERN_FLAG(MNTK_NO_IOPF);
3533 MNT_KERN_FLAG(MNTK_VGONE_UPPER);
3534 MNT_KERN_FLAG(MNTK_VGONE_WAITER);
3535 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT);
3536 MNT_KERN_FLAG(MNTK_MARKER);
3537 MNT_KERN_FLAG(MNTK_USES_BCACHE);
3538 MNT_KERN_FLAG(MNTK_NOASYNC);
3539 MNT_KERN_FLAG(MNTK_UNMOUNT);
3540 MNT_KERN_FLAG(MNTK_MWAIT);
3541 MNT_KERN_FLAG(MNTK_SUSPEND);
3542 MNT_KERN_FLAG(MNTK_SUSPEND2);
3543 MNT_KERN_FLAG(MNTK_SUSPENDED);
3544 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
3545 MNT_KERN_FLAG(MNTK_NOKNOTE);
3546 #undef MNT_KERN_FLAG
3547 if (flags != 0) {
3548 if (buf[0] != '\0')
3549 strlcat(buf, ", ", sizeof(buf));
3550 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3551 "0x%08x", flags);
3552 }
3553 db_printf(" mnt_kern_flag = %s\n", buf);
3554
3555 db_printf(" mnt_opt = ");
3556 opt = TAILQ_FIRST(mp->mnt_opt);
3557 if (opt != NULL) {
3558 db_printf("%s", opt->name);
3559 opt = TAILQ_NEXT(opt, link);
3560 while (opt != NULL) {
3561 db_printf(", %s", opt->name);
3562 opt = TAILQ_NEXT(opt, link);
3563 }
3564 }
3565 db_printf("\n");
3566
3567 sp = &mp->mnt_stat;
3568 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
3569 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
3570 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
3571 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
3572 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
3573 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
3574 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
3575 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
3576 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
3577 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
3578 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
3579 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
3580
3581 db_printf(" mnt_cred = { uid=%u ruid=%u",
3582 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
3583 if (jailed(mp->mnt_cred))
3584 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
3585 db_printf(" }\n");
3586 db_printf(" mnt_ref = %d\n", mp->mnt_ref);
3587 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
3588 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
3589 db_printf(" mnt_activevnodelistsize = %d\n",
3590 mp->mnt_activevnodelistsize);
3591 db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
3592 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
3593 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
3594 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
3595 db_printf(" mnt_lockref = %d\n", mp->mnt_lockref);
3596 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
3597 db_printf(" mnt_secondary_accwrites = %d\n",
3598 mp->mnt_secondary_accwrites);
3599 db_printf(" mnt_gjprovider = %s\n",
3600 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
3601
3602 db_printf("\n\nList of active vnodes\n");
3603 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
3604 if (vp->v_type != VMARKER) {
3605 vn_printf(vp, "vnode ");
3606 if (db_pager_quit)
3607 break;
3608 }
3609 }
3610 db_printf("\n\nList of inactive vnodes\n");
3611 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3612 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
3613 vn_printf(vp, "vnode ");
3614 if (db_pager_quit)
3615 break;
3616 }
3617 }
3618 }
3619 #endif /* DDB */
3620
3621 /*
3622 * Fill in a struct xvfsconf based on a struct vfsconf.
3623 */
3624 static int
3625 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
3626 {
3627 struct xvfsconf xvfsp;
3628
3629 bzero(&xvfsp, sizeof(xvfsp));
3630 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3631 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3632 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3633 xvfsp.vfc_flags = vfsp->vfc_flags;
3634 /*
3635 * These are unused in userland, we keep them
3636 * to not break binary compatibility.
3637 */
3638 xvfsp.vfc_vfsops = NULL;
3639 xvfsp.vfc_next = NULL;
3640 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3641 }
3642
3643 #ifdef COMPAT_FREEBSD32
3644 struct xvfsconf32 {
3645 uint32_t vfc_vfsops;
3646 char vfc_name[MFSNAMELEN];
3647 int32_t vfc_typenum;
3648 int32_t vfc_refcount;
3649 int32_t vfc_flags;
3650 uint32_t vfc_next;
3651 };
3652
3653 static int
3654 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
3655 {
3656 struct xvfsconf32 xvfsp;
3657
3658 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
3659 xvfsp.vfc_typenum = vfsp->vfc_typenum;
3660 xvfsp.vfc_refcount = vfsp->vfc_refcount;
3661 xvfsp.vfc_flags = vfsp->vfc_flags;
3662 xvfsp.vfc_vfsops = 0;
3663 xvfsp.vfc_next = 0;
3664 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
3665 }
3666 #endif
3667
3668 /*
3669 * Top level filesystem related information gathering.
3670 */
3671 static int
3672 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
3673 {
3674 struct vfsconf *vfsp;
3675 int error;
3676
3677 error = 0;
3678 vfsconf_slock();
3679 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3680 #ifdef COMPAT_FREEBSD32
3681 if (req->flags & SCTL_MASK32)
3682 error = vfsconf2x32(req, vfsp);
3683 else
3684 #endif
3685 error = vfsconf2x(req, vfsp);
3686 if (error)
3687 break;
3688 }
3689 vfsconf_sunlock();
3690 return (error);
3691 }
3692
3693 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
3694 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
3695 "S,xvfsconf", "List of all configured filesystems");
3696
3697 #ifndef BURN_BRIDGES
3698 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
3699
3700 static int
3701 vfs_sysctl(SYSCTL_HANDLER_ARGS)
3702 {
3703 int *name = (int *)arg1 - 1; /* XXX */
3704 u_int namelen = arg2 + 1; /* XXX */
3705 struct vfsconf *vfsp;
3706
3707 log(LOG_WARNING, "userland calling deprecated sysctl, "
3708 "please rebuild world\n");
3709
3710 #if 1 || defined(COMPAT_PRELITE2)
3711 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
3712 if (namelen == 1)
3713 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
3714 #endif
3715
3716 switch (name[1]) {
3717 case VFS_MAXTYPENUM:
3718 if (namelen != 2)
3719 return (ENOTDIR);
3720 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
3721 case VFS_CONF:
3722 if (namelen != 3)
3723 return (ENOTDIR); /* overloaded */
3724 vfsconf_slock();
3725 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3726 if (vfsp->vfc_typenum == name[2])
3727 break;
3728 }
3729 vfsconf_sunlock();
3730 if (vfsp == NULL)
3731 return (EOPNOTSUPP);
3732 #ifdef COMPAT_FREEBSD32
3733 if (req->flags & SCTL_MASK32)
3734 return (vfsconf2x32(req, vfsp));
3735 else
3736 #endif
3737 return (vfsconf2x(req, vfsp));
3738 }
3739 return (EOPNOTSUPP);
3740 }
3741
3742 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
3743 CTLFLAG_MPSAFE, vfs_sysctl,
3744 "Generic filesystem");
3745
3746 #if 1 || defined(COMPAT_PRELITE2)
3747
3748 static int
3749 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
3750 {
3751 int error;
3752 struct vfsconf *vfsp;
3753 struct ovfsconf ovfs;
3754
3755 vfsconf_slock();
3756 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
3757 bzero(&ovfs, sizeof(ovfs));
3758 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
3759 strcpy(ovfs.vfc_name, vfsp->vfc_name);
3760 ovfs.vfc_index = vfsp->vfc_typenum;
3761 ovfs.vfc_refcount = vfsp->vfc_refcount;
3762 ovfs.vfc_flags = vfsp->vfc_flags;
3763 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
3764 if (error != 0) {
3765 vfsconf_sunlock();
3766 return (error);
3767 }
3768 }
3769 vfsconf_sunlock();
3770 return (0);
3771 }
3772
3773 #endif /* 1 || COMPAT_PRELITE2 */
3774 #endif /* !BURN_BRIDGES */
3775
3776 #define KINFO_VNODESLOP 10
3777 #ifdef notyet
3778 /*
3779 * Dump vnode list (via sysctl).
3780 */
3781 /* ARGSUSED */
3782 static int
3783 sysctl_vnode(SYSCTL_HANDLER_ARGS)
3784 {
3785 struct xvnode *xvn;
3786 struct mount *mp;
3787 struct vnode *vp;
3788 int error, len, n;
3789
3790 /*
3791 * Stale numvnodes access is not fatal here.
3792 */
3793 req->lock = 0;
3794 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
3795 if (!req->oldptr)
3796 /* Make an estimate */
3797 return (SYSCTL_OUT(req, 0, len));
3798
3799 error = sysctl_wire_old_buffer(req, 0);
3800 if (error != 0)
3801 return (error);
3802 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
3803 n = 0;
3804 mtx_lock(&mountlist_mtx);
3805 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3806 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
3807 continue;
3808 MNT_ILOCK(mp);
3809 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3810 if (n == len)
3811 break;
3812 vref(vp);
3813 xvn[n].xv_size = sizeof *xvn;
3814 xvn[n].xv_vnode = vp;
3815 xvn[n].xv_id = 0; /* XXX compat */
3816 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
3817 XV_COPY(usecount);
3818 XV_COPY(writecount);
3819 XV_COPY(holdcnt);
3820 XV_COPY(mount);
3821 XV_COPY(numoutput);
3822 XV_COPY(type);
3823 #undef XV_COPY
3824 xvn[n].xv_flag = vp->v_vflag;
3825
3826 switch (vp->v_type) {
3827 case VREG:
3828 case VDIR:
3829 case VLNK:
3830 break;
3831 case VBLK:
3832 case VCHR:
3833 if (vp->v_rdev == NULL) {
3834 vrele(vp);
3835 continue;
3836 }
3837 xvn[n].xv_dev = dev2udev(vp->v_rdev);
3838 break;
3839 case VSOCK:
3840 xvn[n].xv_socket = vp->v_socket;
3841 break;
3842 case VFIFO:
3843 xvn[n].xv_fifo = vp->v_fifoinfo;
3844 break;
3845 case VNON:
3846 case VBAD:
3847 default:
3848 /* shouldn't happen? */
3849 vrele(vp);
3850 continue;
3851 }
3852 vrele(vp);
3853 ++n;
3854 }
3855 MNT_IUNLOCK(mp);
3856 mtx_lock(&mountlist_mtx);
3857 vfs_unbusy(mp);
3858 if (n == len)
3859 break;
3860 }
3861 mtx_unlock(&mountlist_mtx);
3862
3863 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
3864 free(xvn, M_TEMP);
3865 return (error);
3866 }
3867
3868 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD |
3869 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode",
3870 "");
3871 #endif
3872
3873 static void
3874 unmount_or_warn(struct mount *mp)
3875 {
3876 int error;
3877
3878 error = dounmount(mp, MNT_FORCE, curthread);
3879 if (error != 0) {
3880 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
3881 if (error == EBUSY)
3882 printf("BUSY)\n");
3883 else
3884 printf("%d)\n", error);
3885 }
3886 }
3887
3888 /*
3889 * Unmount all filesystems. The list is traversed in reverse order
3890 * of mounting to avoid dependencies.
3891 */
3892 void
3893 vfs_unmountall(void)
3894 {
3895 struct mount *mp, *tmp;
3896
3897 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
3898
3899 /*
3900 * Since this only runs when rebooting, it is not interlocked.
3901 */
3902 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
3903 vfs_ref(mp);
3904
3905 /*
3906 * Forcibly unmounting "/dev" before "/" would prevent clean
3907 * unmount of the latter.
3908 */
3909 if (mp == rootdevmp)
3910 continue;
3911
3912 unmount_or_warn(mp);
3913 }
3914
3915 if (rootdevmp != NULL)
3916 unmount_or_warn(rootdevmp);
3917 }
3918
3919 /*
3920 * perform msync on all vnodes under a mount point
3921 * the mount point must be locked.
3922 */
3923 void
3924 vfs_msync(struct mount *mp, int flags)
3925 {
3926 struct vnode *vp, *mvp;
3927 struct vm_object *obj;
3928
3929 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
3930 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
3931 obj = vp->v_object;
3932 if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
3933 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
3934 if (!vget(vp,
3935 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
3936 curthread)) {
3937 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
3938 vput(vp);
3939 continue;
3940 }
3941
3942 obj = vp->v_object;
3943 if (obj != NULL) {
3944 VM_OBJECT_WLOCK(obj);
3945 vm_object_page_clean(obj, 0, 0,
3946 flags == MNT_WAIT ?
3947 OBJPC_SYNC : OBJPC_NOSYNC);
3948 VM_OBJECT_WUNLOCK(obj);
3949 }
3950 vput(vp);
3951 }
3952 } else
3953 VI_UNLOCK(vp);
3954 }
3955 }
3956
3957 static void
3958 destroy_vpollinfo_free(struct vpollinfo *vi)
3959 {
3960
3961 knlist_destroy(&vi->vpi_selinfo.si_note);
3962 mtx_destroy(&vi->vpi_lock);
3963 uma_zfree(vnodepoll_zone, vi);
3964 }
3965
3966 static void
3967 destroy_vpollinfo(struct vpollinfo *vi)
3968 {
3969
3970 knlist_clear(&vi->vpi_selinfo.si_note, 1);
3971 seldrain(&vi->vpi_selinfo);
3972 destroy_vpollinfo_free(vi);
3973 }
3974
3975 /*
3976 * Initialize per-vnode helper structure to hold poll-related state.
3977 */
3978 void
3979 v_addpollinfo(struct vnode *vp)
3980 {
3981 struct vpollinfo *vi;
3982
3983 if (vp->v_pollinfo != NULL)
3984 return;
3985 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO);
3986 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
3987 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
3988 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
3989 VI_LOCK(vp);
3990 if (vp->v_pollinfo != NULL) {
3991 VI_UNLOCK(vp);
3992 destroy_vpollinfo_free(vi);
3993 return;
3994 }
3995 vp->v_pollinfo = vi;
3996 VI_UNLOCK(vp);
3997 }
3998
3999 /*
4000 * Record a process's interest in events which might happen to
4001 * a vnode. Because poll uses the historic select-style interface
4002 * internally, this routine serves as both the ``check for any
4003 * pending events'' and the ``record my interest in future events''
4004 * functions. (These are done together, while the lock is held,
4005 * to avoid race conditions.)
4006 */
4007 int
4008 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
4009 {
4010
4011 v_addpollinfo(vp);
4012 mtx_lock(&vp->v_pollinfo->vpi_lock);
4013 if (vp->v_pollinfo->vpi_revents & events) {
4014 /*
4015 * This leaves events we are not interested
4016 * in available for the other process which
4017 * which presumably had requested them
4018 * (otherwise they would never have been
4019 * recorded).
4020 */
4021 events &= vp->v_pollinfo->vpi_revents;
4022 vp->v_pollinfo->vpi_revents &= ~events;
4023
4024 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4025 return (events);
4026 }
4027 vp->v_pollinfo->vpi_events |= events;
4028 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
4029 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4030 return (0);
4031 }
4032
4033 /*
4034 * Routine to create and manage a filesystem syncer vnode.
4035 */
4036 #define sync_close ((int (*)(struct vop_close_args *))nullop)
4037 static int sync_fsync(struct vop_fsync_args *);
4038 static int sync_inactive(struct vop_inactive_args *);
4039 static int sync_reclaim(struct vop_reclaim_args *);
4040
4041 static struct vop_vector sync_vnodeops = {
4042 .vop_bypass = VOP_EOPNOTSUPP,
4043 .vop_close = sync_close, /* close */
4044 .vop_fsync = sync_fsync, /* fsync */
4045 .vop_inactive = sync_inactive, /* inactive */
4046 .vop_reclaim = sync_reclaim, /* reclaim */
4047 .vop_lock1 = vop_stdlock, /* lock */
4048 .vop_unlock = vop_stdunlock, /* unlock */
4049 .vop_islocked = vop_stdislocked, /* islocked */
4050 };
4051
4052 /*
4053 * Create a new filesystem syncer vnode for the specified mount point.
4054 */
4055 void
4056 vfs_allocate_syncvnode(struct mount *mp)
4057 {
4058 struct vnode *vp;
4059 struct bufobj *bo;
4060 static long start, incr, next;
4061 int error;
4062
4063 /* Allocate a new vnode */
4064 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
4065 if (error != 0)
4066 panic("vfs_allocate_syncvnode: getnewvnode() failed");
4067 vp->v_type = VNON;
4068 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4069 vp->v_vflag |= VV_FORCEINSMQ;
4070 error = insmntque(vp, mp);
4071 if (error != 0)
4072 panic("vfs_allocate_syncvnode: insmntque() failed");
4073 vp->v_vflag &= ~VV_FORCEINSMQ;
4074 VOP_UNLOCK(vp, 0);
4075 /*
4076 * Place the vnode onto the syncer worklist. We attempt to
4077 * scatter them about on the list so that they will go off
4078 * at evenly distributed times even if all the filesystems
4079 * are mounted at once.
4080 */
4081 next += incr;
4082 if (next == 0 || next > syncer_maxdelay) {
4083 start /= 2;
4084 incr /= 2;
4085 if (start == 0) {
4086 start = syncer_maxdelay / 2;
4087 incr = syncer_maxdelay;
4088 }
4089 next = start;
4090 }
4091 bo = &vp->v_bufobj;
4092 BO_LOCK(bo);
4093 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
4094 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
4095 mtx_lock(&sync_mtx);
4096 sync_vnode_count++;
4097 if (mp->mnt_syncer == NULL) {
4098 mp->mnt_syncer = vp;
4099 vp = NULL;
4100 }
4101 mtx_unlock(&sync_mtx);
4102 BO_UNLOCK(bo);
4103 if (vp != NULL) {
4104 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4105 vgone(vp);
4106 vput(vp);
4107 }
4108 }
4109
4110 void
4111 vfs_deallocate_syncvnode(struct mount *mp)
4112 {
4113 struct vnode *vp;
4114
4115 mtx_lock(&sync_mtx);
4116 vp = mp->mnt_syncer;
4117 if (vp != NULL)
4118 mp->mnt_syncer = NULL;
4119 mtx_unlock(&sync_mtx);
4120 if (vp != NULL)
4121 vrele(vp);
4122 }
4123
4124 /*
4125 * Do a lazy sync of the filesystem.
4126 */
4127 static int
4128 sync_fsync(struct vop_fsync_args *ap)
4129 {
4130 struct vnode *syncvp = ap->a_vp;
4131 struct mount *mp = syncvp->v_mount;
4132 int error, save;
4133 struct bufobj *bo;
4134
4135 /*
4136 * We only need to do something if this is a lazy evaluation.
4137 */
4138 if (ap->a_waitfor != MNT_LAZY)
4139 return (0);
4140
4141 /*
4142 * Move ourselves to the back of the sync list.
4143 */
4144 bo = &syncvp->v_bufobj;
4145 BO_LOCK(bo);
4146 vn_syncer_add_to_worklist(bo, syncdelay);
4147 BO_UNLOCK(bo);
4148
4149 /*
4150 * Walk the list of vnodes pushing all that are dirty and
4151 * not already on the sync list.
4152 */
4153 if (vfs_busy(mp, MBF_NOWAIT) != 0)
4154 return (0);
4155 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
4156 vfs_unbusy(mp);
4157 return (0);
4158 }
4159 save = curthread_pflags_set(TDP_SYNCIO);
4160 vfs_msync(mp, MNT_NOWAIT);
4161 error = VFS_SYNC(mp, MNT_LAZY);
4162 curthread_pflags_restore(save);
4163 vn_finished_write(mp);
4164 vfs_unbusy(mp);
4165 return (error);
4166 }
4167
4168 /*
4169 * The syncer vnode is no referenced.
4170 */
4171 static int
4172 sync_inactive(struct vop_inactive_args *ap)
4173 {
4174
4175 vgone(ap->a_vp);
4176 return (0);
4177 }
4178
4179 /*
4180 * The syncer vnode is no longer needed and is being decommissioned.
4181 *
4182 * Modifications to the worklist must be protected by sync_mtx.
4183 */
4184 static int
4185 sync_reclaim(struct vop_reclaim_args *ap)
4186 {
4187 struct vnode *vp = ap->a_vp;
4188 struct bufobj *bo;
4189
4190 bo = &vp->v_bufobj;
4191 BO_LOCK(bo);
4192 mtx_lock(&sync_mtx);
4193 if (vp->v_mount->mnt_syncer == vp)
4194 vp->v_mount->mnt_syncer = NULL;
4195 if (bo->bo_flag & BO_ONWORKLST) {
4196 LIST_REMOVE(bo, bo_synclist);
4197 syncer_worklist_len--;
4198 sync_vnode_count--;
4199 bo->bo_flag &= ~BO_ONWORKLST;
4200 }
4201 mtx_unlock(&sync_mtx);
4202 BO_UNLOCK(bo);
4203
4204 return (0);
4205 }
4206
4207 /*
4208 * Check if vnode represents a disk device
4209 */
4210 int
4211 vn_isdisk(struct vnode *vp, int *errp)
4212 {
4213 int error;
4214
4215 if (vp->v_type != VCHR) {
4216 error = ENOTBLK;
4217 goto out;
4218 }
4219 error = 0;
4220 dev_lock();
4221 if (vp->v_rdev == NULL)
4222 error = ENXIO;
4223 else if (vp->v_rdev->si_devsw == NULL)
4224 error = ENXIO;
4225 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
4226 error = ENOTBLK;
4227 dev_unlock();
4228 out:
4229 if (errp != NULL)
4230 *errp = error;
4231 return (error == 0);
4232 }
4233
4234 /*
4235 * Common filesystem object access control check routine. Accepts a
4236 * vnode's type, "mode", uid and gid, requested access mode, credentials,
4237 * and optional call-by-reference privused argument allowing vaccess()
4238 * to indicate to the caller whether privilege was used to satisfy the
4239 * request (obsoleted). Returns 0 on success, or an errno on failure.
4240 */
4241 int
4242 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
4243 accmode_t accmode, struct ucred *cred, int *privused)
4244 {
4245 accmode_t dac_granted;
4246 accmode_t priv_granted;
4247
4248 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
4249 ("invalid bit in accmode"));
4250 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
4251 ("VAPPEND without VWRITE"));
4252
4253 /*
4254 * Look for a normal, non-privileged way to access the file/directory
4255 * as requested. If it exists, go with that.
4256 */
4257
4258 if (privused != NULL)
4259 *privused = 0;
4260
4261 dac_granted = 0;
4262
4263 /* Check the owner. */
4264 if (cred->cr_uid == file_uid) {
4265 dac_granted |= VADMIN;
4266 if (file_mode & S_IXUSR)
4267 dac_granted |= VEXEC;
4268 if (file_mode & S_IRUSR)
4269 dac_granted |= VREAD;
4270 if (file_mode & S_IWUSR)
4271 dac_granted |= (VWRITE | VAPPEND);
4272
4273 if ((accmode & dac_granted) == accmode)
4274 return (0);
4275
4276 goto privcheck;
4277 }
4278
4279 /* Otherwise, check the groups (first match) */
4280 if (groupmember(file_gid, cred)) {
4281 if (file_mode & S_IXGRP)
4282 dac_granted |= VEXEC;
4283 if (file_mode & S_IRGRP)
4284 dac_granted |= VREAD;
4285 if (file_mode & S_IWGRP)
4286 dac_granted |= (VWRITE | VAPPEND);
4287
4288 if ((accmode & dac_granted) == accmode)
4289 return (0);
4290
4291 goto privcheck;
4292 }
4293
4294 /* Otherwise, check everyone else. */
4295 if (file_mode & S_IXOTH)
4296 dac_granted |= VEXEC;
4297 if (file_mode & S_IROTH)
4298 dac_granted |= VREAD;
4299 if (file_mode & S_IWOTH)
4300 dac_granted |= (VWRITE | VAPPEND);
4301 if ((accmode & dac_granted) == accmode)
4302 return (0);
4303
4304 privcheck:
4305 /*
4306 * Build a privilege mask to determine if the set of privileges
4307 * satisfies the requirements when combined with the granted mask
4308 * from above. For each privilege, if the privilege is required,
4309 * bitwise or the request type onto the priv_granted mask.
4310 */
4311 priv_granted = 0;
4312
4313 if (type == VDIR) {
4314 /*
4315 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
4316 * requests, instead of PRIV_VFS_EXEC.
4317 */
4318 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4319 !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
4320 priv_granted |= VEXEC;
4321 } else {
4322 /*
4323 * Ensure that at least one execute bit is on. Otherwise,
4324 * a privileged user will always succeed, and we don't want
4325 * this to happen unless the file really is executable.
4326 */
4327 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4328 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
4329 !priv_check_cred(cred, PRIV_VFS_EXEC, 0))
4330 priv_granted |= VEXEC;
4331 }
4332
4333 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
4334 !priv_check_cred(cred, PRIV_VFS_READ, 0))
4335 priv_granted |= VREAD;
4336
4337 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
4338 !priv_check_cred(cred, PRIV_VFS_WRITE, 0))
4339 priv_granted |= (VWRITE | VAPPEND);
4340
4341 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
4342 !priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
4343 priv_granted |= VADMIN;
4344
4345 if ((accmode & (priv_granted | dac_granted)) == accmode) {
4346 /* XXX audit: privilege used */
4347 if (privused != NULL)
4348 *privused = 1;
4349 return (0);
4350 }
4351
4352 return ((accmode & VADMIN) ? EPERM : EACCES);
4353 }
4354
4355 /*
4356 * Credential check based on process requesting service, and per-attribute
4357 * permissions.
4358 */
4359 int
4360 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
4361 struct thread *td, accmode_t accmode)
4362 {
4363
4364 /*
4365 * Kernel-invoked always succeeds.
4366 */
4367 if (cred == NOCRED)
4368 return (0);
4369
4370 /*
4371 * Do not allow privileged processes in jail to directly manipulate
4372 * system attributes.
4373 */
4374 switch (attrnamespace) {
4375 case EXTATTR_NAMESPACE_SYSTEM:
4376 /* Potentially should be: return (EPERM); */
4377 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
4378 case EXTATTR_NAMESPACE_USER:
4379 return (VOP_ACCESS(vp, accmode, cred, td));
4380 default:
4381 return (EPERM);
4382 }
4383 }
4384
4385 #ifdef DEBUG_VFS_LOCKS
4386 /*
4387 * This only exists to suppress warnings from unlocked specfs accesses. It is
4388 * no longer ok to have an unlocked VFS.
4389 */
4390 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
4391 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
4392
4393 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
4394 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
4395 "Drop into debugger on lock violation");
4396
4397 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
4398 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
4399 0, "Check for interlock across VOPs");
4400
4401 int vfs_badlock_print = 1; /* Print lock violations. */
4402 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
4403 0, "Print lock violations");
4404
4405 #ifdef KDB
4406 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
4407 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
4408 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
4409 #endif
4410
4411 static void
4412 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
4413 {
4414
4415 #ifdef KDB
4416 if (vfs_badlock_backtrace)
4417 kdb_backtrace();
4418 #endif
4419 if (vfs_badlock_print)
4420 printf("%s: %p %s\n", str, (void *)vp, msg);
4421 if (vfs_badlock_ddb)
4422 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4423 }
4424
4425 void
4426 assert_vi_locked(struct vnode *vp, const char *str)
4427 {
4428
4429 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
4430 vfs_badlock("interlock is not locked but should be", str, vp);
4431 }
4432
4433 void
4434 assert_vi_unlocked(struct vnode *vp, const char *str)
4435 {
4436
4437 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
4438 vfs_badlock("interlock is locked but should not be", str, vp);
4439 }
4440
4441 void
4442 assert_vop_locked(struct vnode *vp, const char *str)
4443 {
4444 int locked;
4445
4446 if (!IGNORE_LOCK(vp)) {
4447 locked = VOP_ISLOCKED(vp);
4448 if (locked == 0 || locked == LK_EXCLOTHER)
4449 vfs_badlock("is not locked but should be", str, vp);
4450 }
4451 }
4452
4453 void
4454 assert_vop_unlocked(struct vnode *vp, const char *str)
4455 {
4456
4457 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
4458 vfs_badlock("is locked but should not be", str, vp);
4459 }
4460
4461 void
4462 assert_vop_elocked(struct vnode *vp, const char *str)
4463 {
4464
4465 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
4466 vfs_badlock("is not exclusive locked but should be", str, vp);
4467 }
4468
4469 #if 0
4470 void
4471 assert_vop_elocked_other(struct vnode *vp, const char *str)
4472 {
4473
4474 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLOTHER)
4475 vfs_badlock("is not exclusive locked by another thread",
4476 str, vp);
4477 }
4478
4479 void
4480 assert_vop_slocked(struct vnode *vp, const char *str)
4481 {
4482
4483 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_SHARED)
4484 vfs_badlock("is not locked shared but should be", str, vp);
4485 }
4486 #endif /* 0 */
4487 #endif /* DEBUG_VFS_LOCKS */
4488
4489 void
4490 vop_rename_fail(struct vop_rename_args *ap)
4491 {
4492
4493 if (ap->a_tvp != NULL)
4494 vput(ap->a_tvp);
4495 if (ap->a_tdvp == ap->a_tvp)
4496 vrele(ap->a_tdvp);
4497 else
4498 vput(ap->a_tdvp);
4499 vrele(ap->a_fdvp);
4500 vrele(ap->a_fvp);
4501 }
4502
4503 void
4504 vop_rename_pre(void *ap)
4505 {
4506 struct vop_rename_args *a = ap;
4507
4508 #ifdef DEBUG_VFS_LOCKS
4509 if (a->a_tvp)
4510 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
4511 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
4512 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
4513 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
4514
4515 /* Check the source (from). */
4516 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
4517 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
4518 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
4519 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
4520 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
4521
4522 /* Check the target. */
4523 if (a->a_tvp)
4524 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
4525 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
4526 #endif
4527 if (a->a_tdvp != a->a_fdvp)
4528 vhold(a->a_fdvp);
4529 if (a->a_tvp != a->a_fvp)
4530 vhold(a->a_fvp);
4531 vhold(a->a_tdvp);
4532 if (a->a_tvp)
4533 vhold(a->a_tvp);
4534 }
4535
4536 #ifdef DEBUG_VFS_LOCKS
4537 void
4538 vop_strategy_pre(void *ap)
4539 {
4540 struct vop_strategy_args *a;
4541 struct buf *bp;
4542
4543 a = ap;
4544 bp = a->a_bp;
4545
4546 /*
4547 * Cluster ops lock their component buffers but not the IO container.
4548 */
4549 if ((bp->b_flags & B_CLUSTER) != 0)
4550 return;
4551
4552 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
4553 if (vfs_badlock_print)
4554 printf(
4555 "VOP_STRATEGY: bp is not locked but should be\n");
4556 if (vfs_badlock_ddb)
4557 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4558 }
4559 }
4560
4561 void
4562 vop_lock_pre(void *ap)
4563 {
4564 struct vop_lock1_args *a = ap;
4565
4566 if ((a->a_flags & LK_INTERLOCK) == 0)
4567 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4568 else
4569 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
4570 }
4571
4572 void
4573 vop_lock_post(void *ap, int rc)
4574 {
4575 struct vop_lock1_args *a = ap;
4576
4577 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
4578 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
4579 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
4580 }
4581
4582 void
4583 vop_unlock_pre(void *ap)
4584 {
4585 struct vop_unlock_args *a = ap;
4586
4587 if (a->a_flags & LK_INTERLOCK)
4588 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
4589 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
4590 }
4591
4592 void
4593 vop_unlock_post(void *ap, int rc)
4594 {
4595 struct vop_unlock_args *a = ap;
4596
4597 if (a->a_flags & LK_INTERLOCK)
4598 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
4599 }
4600 #endif
4601
4602 void
4603 vop_create_post(void *ap, int rc)
4604 {
4605 struct vop_create_args *a = ap;
4606
4607 if (!rc)
4608 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4609 }
4610
4611 void
4612 vop_deleteextattr_post(void *ap, int rc)
4613 {
4614 struct vop_deleteextattr_args *a = ap;
4615
4616 if (!rc)
4617 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4618 }
4619
4620 void
4621 vop_link_post(void *ap, int rc)
4622 {
4623 struct vop_link_args *a = ap;
4624
4625 if (!rc) {
4626 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
4627 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
4628 }
4629 }
4630
4631 void
4632 vop_mkdir_post(void *ap, int rc)
4633 {
4634 struct vop_mkdir_args *a = ap;
4635
4636 if (!rc)
4637 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4638 }
4639
4640 void
4641 vop_mknod_post(void *ap, int rc)
4642 {
4643 struct vop_mknod_args *a = ap;
4644
4645 if (!rc)
4646 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4647 }
4648
4649 void
4650 vop_reclaim_post(void *ap, int rc)
4651 {
4652 struct vop_reclaim_args *a = ap;
4653
4654 if (!rc)
4655 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE);
4656 }
4657
4658 void
4659 vop_remove_post(void *ap, int rc)
4660 {
4661 struct vop_remove_args *a = ap;
4662
4663 if (!rc) {
4664 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4665 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4666 }
4667 }
4668
4669 void
4670 vop_rename_post(void *ap, int rc)
4671 {
4672 struct vop_rename_args *a = ap;
4673 long hint;
4674
4675 if (!rc) {
4676 hint = NOTE_WRITE;
4677 if (a->a_fdvp == a->a_tdvp) {
4678 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
4679 hint |= NOTE_LINK;
4680 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
4681 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
4682 } else {
4683 hint |= NOTE_EXTEND;
4684 if (a->a_fvp->v_type == VDIR)
4685 hint |= NOTE_LINK;
4686 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
4687
4688 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
4689 a->a_tvp->v_type == VDIR)
4690 hint &= ~NOTE_LINK;
4691 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
4692 }
4693
4694 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
4695 if (a->a_tvp)
4696 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
4697 }
4698 if (a->a_tdvp != a->a_fdvp)
4699 vdrop(a->a_fdvp);
4700 if (a->a_tvp != a->a_fvp)
4701 vdrop(a->a_fvp);
4702 vdrop(a->a_tdvp);
4703 if (a->a_tvp)
4704 vdrop(a->a_tvp);
4705 }
4706
4707 void
4708 vop_rmdir_post(void *ap, int rc)
4709 {
4710 struct vop_rmdir_args *a = ap;
4711
4712 if (!rc) {
4713 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
4714 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
4715 }
4716 }
4717
4718 void
4719 vop_setattr_post(void *ap, int rc)
4720 {
4721 struct vop_setattr_args *a = ap;
4722
4723 if (!rc)
4724 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4725 }
4726
4727 void
4728 vop_setextattr_post(void *ap, int rc)
4729 {
4730 struct vop_setextattr_args *a = ap;
4731
4732 if (!rc)
4733 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
4734 }
4735
4736 void
4737 vop_symlink_post(void *ap, int rc)
4738 {
4739 struct vop_symlink_args *a = ap;
4740
4741 if (!rc)
4742 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
4743 }
4744
4745 void
4746 vop_open_post(void *ap, int rc)
4747 {
4748 struct vop_open_args *a = ap;
4749
4750 if (!rc)
4751 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
4752 }
4753
4754 void
4755 vop_close_post(void *ap, int rc)
4756 {
4757 struct vop_close_args *a = ap;
4758
4759 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
4760 (a->a_vp->v_iflag & VI_DOOMED) == 0)) {
4761 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
4762 NOTE_CLOSE_WRITE : NOTE_CLOSE);
4763 }
4764 }
4765
4766 void
4767 vop_read_post(void *ap, int rc)
4768 {
4769 struct vop_read_args *a = ap;
4770
4771 if (!rc)
4772 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
4773 }
4774
4775 void
4776 vop_readdir_post(void *ap, int rc)
4777 {
4778 struct vop_readdir_args *a = ap;
4779
4780 if (!rc)
4781 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
4782 }
4783
4784 static struct knlist fs_knlist;
4785
4786 static void
4787 vfs_event_init(void *arg)
4788 {
4789 knlist_init_mtx(&fs_knlist, NULL);
4790 }
4791 /* XXX - correct order? */
4792 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
4793
4794 void
4795 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
4796 {
4797
4798 KNOTE_UNLOCKED(&fs_knlist, event);
4799 }
4800
4801 static int filt_fsattach(struct knote *kn);
4802 static void filt_fsdetach(struct knote *kn);
4803 static int filt_fsevent(struct knote *kn, long hint);
4804
4805 struct filterops fs_filtops = {
4806 .f_isfd = 0,
4807 .f_attach = filt_fsattach,
4808 .f_detach = filt_fsdetach,
4809 .f_event = filt_fsevent
4810 };
4811
4812 static int
4813 filt_fsattach(struct knote *kn)
4814 {
4815
4816 kn->kn_flags |= EV_CLEAR;
4817 knlist_add(&fs_knlist, kn, 0);
4818 return (0);
4819 }
4820
4821 static void
4822 filt_fsdetach(struct knote *kn)
4823 {
4824
4825 knlist_remove(&fs_knlist, kn, 0);
4826 }
4827
4828 static int
4829 filt_fsevent(struct knote *kn, long hint)
4830 {
4831
4832 kn->kn_fflags |= hint;
4833 return (kn->kn_fflags != 0);
4834 }
4835
4836 static int
4837 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
4838 {
4839 struct vfsidctl vc;
4840 int error;
4841 struct mount *mp;
4842
4843 error = SYSCTL_IN(req, &vc, sizeof(vc));
4844 if (error)
4845 return (error);
4846 if (vc.vc_vers != VFS_CTL_VERS1)
4847 return (EINVAL);
4848 mp = vfs_getvfs(&vc.vc_fsid);
4849 if (mp == NULL)
4850 return (ENOENT);
4851 /* ensure that a specific sysctl goes to the right filesystem. */
4852 if (strcmp(vc.vc_fstypename, "*") != 0 &&
4853 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
4854 vfs_rel(mp);
4855 return (EINVAL);
4856 }
4857 VCTLTOREQ(&vc, req);
4858 error = VFS_SYSCTL(mp, vc.vc_op, req);
4859 vfs_rel(mp);
4860 return (error);
4861 }
4862
4863 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
4864 NULL, 0, sysctl_vfs_ctl, "",
4865 "Sysctl by fsid");
4866
4867 /*
4868 * Function to initialize a va_filerev field sensibly.
4869 * XXX: Wouldn't a random number make a lot more sense ??
4870 */
4871 u_quad_t
4872 init_va_filerev(void)
4873 {
4874 struct bintime bt;
4875
4876 getbinuptime(&bt);
4877 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
4878 }
4879
4880 static int filt_vfsread(struct knote *kn, long hint);
4881 static int filt_vfswrite(struct knote *kn, long hint);
4882 static int filt_vfsvnode(struct knote *kn, long hint);
4883 static void filt_vfsdetach(struct knote *kn);
4884 static struct filterops vfsread_filtops = {
4885 .f_isfd = 1,
4886 .f_detach = filt_vfsdetach,
4887 .f_event = filt_vfsread
4888 };
4889 static struct filterops vfswrite_filtops = {
4890 .f_isfd = 1,
4891 .f_detach = filt_vfsdetach,
4892 .f_event = filt_vfswrite
4893 };
4894 static struct filterops vfsvnode_filtops = {
4895 .f_isfd = 1,
4896 .f_detach = filt_vfsdetach,
4897 .f_event = filt_vfsvnode
4898 };
4899
4900 static void
4901 vfs_knllock(void *arg)
4902 {
4903 struct vnode *vp = arg;
4904
4905 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4906 }
4907
4908 static void
4909 vfs_knlunlock(void *arg)
4910 {
4911 struct vnode *vp = arg;
4912
4913 VOP_UNLOCK(vp, 0);
4914 }
4915
4916 static void
4917 vfs_knl_assert_locked(void *arg)
4918 {
4919 #ifdef DEBUG_VFS_LOCKS
4920 struct vnode *vp = arg;
4921
4922 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
4923 #endif
4924 }
4925
4926 static void
4927 vfs_knl_assert_unlocked(void *arg)
4928 {
4929 #ifdef DEBUG_VFS_LOCKS
4930 struct vnode *vp = arg;
4931
4932 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
4933 #endif
4934 }
4935
4936 int
4937 vfs_kqfilter(struct vop_kqfilter_args *ap)
4938 {
4939 struct vnode *vp = ap->a_vp;
4940 struct knote *kn = ap->a_kn;
4941 struct knlist *knl;
4942
4943 switch (kn->kn_filter) {
4944 case EVFILT_READ:
4945 kn->kn_fop = &vfsread_filtops;
4946 break;
4947 case EVFILT_WRITE:
4948 kn->kn_fop = &vfswrite_filtops;
4949 break;
4950 case EVFILT_VNODE:
4951 kn->kn_fop = &vfsvnode_filtops;
4952 break;
4953 default:
4954 return (EINVAL);
4955 }
4956
4957 kn->kn_hook = (caddr_t)vp;
4958
4959 v_addpollinfo(vp);
4960 if (vp->v_pollinfo == NULL)
4961 return (ENOMEM);
4962 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
4963 vhold(vp);
4964 knlist_add(knl, kn, 0);
4965
4966 return (0);
4967 }
4968
4969 /*
4970 * Detach knote from vnode
4971 */
4972 static void
4973 filt_vfsdetach(struct knote *kn)
4974 {
4975 struct vnode *vp = (struct vnode *)kn->kn_hook;
4976
4977 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
4978 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
4979 vdrop(vp);
4980 }
4981
4982 /*ARGSUSED*/
4983 static int
4984 filt_vfsread(struct knote *kn, long hint)
4985 {
4986 struct vnode *vp = (struct vnode *)kn->kn_hook;
4987 struct vattr va;
4988 int res;
4989
4990 /*
4991 * filesystem is gone, so set the EOF flag and schedule
4992 * the knote for deletion.
4993 */
4994 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
4995 VI_LOCK(vp);
4996 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
4997 VI_UNLOCK(vp);
4998 return (1);
4999 }
5000
5001 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
5002 return (0);
5003
5004 VI_LOCK(vp);
5005 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
5006 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
5007 VI_UNLOCK(vp);
5008 return (res);
5009 }
5010
5011 /*ARGSUSED*/
5012 static int
5013 filt_vfswrite(struct knote *kn, long hint)
5014 {
5015 struct vnode *vp = (struct vnode *)kn->kn_hook;
5016
5017 VI_LOCK(vp);
5018
5019 /*
5020 * filesystem is gone, so set the EOF flag and schedule
5021 * the knote for deletion.
5022 */
5023 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
5024 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
5025
5026 kn->kn_data = 0;
5027 VI_UNLOCK(vp);
5028 return (1);
5029 }
5030
5031 static int
5032 filt_vfsvnode(struct knote *kn, long hint)
5033 {
5034 struct vnode *vp = (struct vnode *)kn->kn_hook;
5035 int res;
5036
5037 VI_LOCK(vp);
5038 if (kn->kn_sfflags & hint)
5039 kn->kn_fflags |= hint;
5040 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
5041 kn->kn_flags |= EV_EOF;
5042 VI_UNLOCK(vp);
5043 return (1);
5044 }
5045 res = (kn->kn_fflags != 0);
5046 VI_UNLOCK(vp);
5047 return (res);
5048 }
5049
5050 int
5051 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
5052 {
5053 int error;
5054
5055 if (dp->d_reclen > ap->a_uio->uio_resid)
5056 return (ENAMETOOLONG);
5057 error = uiomove(dp, dp->d_reclen, ap->a_uio);
5058 if (error) {
5059 if (ap->a_ncookies != NULL) {
5060 if (ap->a_cookies != NULL)
5061 free(ap->a_cookies, M_TEMP);
5062 ap->a_cookies = NULL;
5063 *ap->a_ncookies = 0;
5064 }
5065 return (error);
5066 }
5067 if (ap->a_ncookies == NULL)
5068 return (0);
5069
5070 KASSERT(ap->a_cookies,
5071 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
5072
5073 *ap->a_cookies = realloc(*ap->a_cookies,
5074 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
5075 (*ap->a_cookies)[*ap->a_ncookies] = off;
5076 *ap->a_ncookies += 1;
5077 return (0);
5078 }
5079
5080 /*
5081 * Mark for update the access time of the file if the filesystem
5082 * supports VOP_MARKATIME. This functionality is used by execve and
5083 * mmap, so we want to avoid the I/O implied by directly setting
5084 * va_atime for the sake of efficiency.
5085 */
5086 void
5087 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
5088 {
5089 struct mount *mp;
5090
5091 mp = vp->v_mount;
5092 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
5093 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
5094 (void)VOP_MARKATIME(vp);
5095 }
5096
5097 /*
5098 * The purpose of this routine is to remove granularity from accmode_t,
5099 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
5100 * VADMIN and VAPPEND.
5101 *
5102 * If it returns 0, the caller is supposed to continue with the usual
5103 * access checks using 'accmode' as modified by this routine. If it
5104 * returns nonzero value, the caller is supposed to return that value
5105 * as errno.
5106 *
5107 * Note that after this routine runs, accmode may be zero.
5108 */
5109 int
5110 vfs_unixify_accmode(accmode_t *accmode)
5111 {
5112 /*
5113 * There is no way to specify explicit "deny" rule using
5114 * file mode or POSIX.1e ACLs.
5115 */
5116 if (*accmode & VEXPLICIT_DENY) {
5117 *accmode = 0;
5118 return (0);
5119 }
5120
5121 /*
5122 * None of these can be translated into usual access bits.
5123 * Also, the common case for NFSv4 ACLs is to not contain
5124 * either of these bits. Caller should check for VWRITE
5125 * on the containing directory instead.
5126 */
5127 if (*accmode & (VDELETE_CHILD | VDELETE))
5128 return (EPERM);
5129
5130 if (*accmode & VADMIN_PERMS) {
5131 *accmode &= ~VADMIN_PERMS;
5132 *accmode |= VADMIN;
5133 }
5134
5135 /*
5136 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
5137 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
5138 */
5139 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
5140
5141 return (0);
5142 }
5143
5144 /*
5145 * These are helper functions for filesystems to traverse all
5146 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
5147 *
5148 * This interface replaces MNT_VNODE_FOREACH.
5149 */
5150
5151 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
5152
5153 struct vnode *
5154 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
5155 {
5156 struct vnode *vp;
5157
5158 if (should_yield())
5159 kern_yield(PRI_USER);
5160 MNT_ILOCK(mp);
5161 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5162 vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
5163 while (vp != NULL && (vp->v_type == VMARKER ||
5164 (vp->v_iflag & VI_DOOMED) != 0))
5165 vp = TAILQ_NEXT(vp, v_nmntvnodes);
5166
5167 /* Check if we are done */
5168 if (vp == NULL) {
5169 __mnt_vnode_markerfree_all(mvp, mp);
5170 /* MNT_IUNLOCK(mp); -- done in above function */
5171 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
5172 return (NULL);
5173 }
5174 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5175 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5176 VI_LOCK(vp);
5177 MNT_IUNLOCK(mp);
5178 return (vp);
5179 }
5180
5181 struct vnode *
5182 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
5183 {
5184 struct vnode *vp;
5185
5186 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
5187 MNT_ILOCK(mp);
5188 MNT_REF(mp);
5189 (*mvp)->v_type = VMARKER;
5190
5191 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
5192 while (vp != NULL && (vp->v_type == VMARKER ||
5193 (vp->v_iflag & VI_DOOMED) != 0))
5194 vp = TAILQ_NEXT(vp, v_nmntvnodes);
5195
5196 /* Check if we are done */
5197 if (vp == NULL) {
5198 MNT_REL(mp);
5199 MNT_IUNLOCK(mp);
5200 free(*mvp, M_VNODE_MARKER);
5201 *mvp = NULL;
5202 return (NULL);
5203 }
5204 (*mvp)->v_mount = mp;
5205 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5206 VI_LOCK(vp);
5207 MNT_IUNLOCK(mp);
5208 return (vp);
5209 }
5210
5211
5212 void
5213 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
5214 {
5215
5216 if (*mvp == NULL) {
5217 MNT_IUNLOCK(mp);
5218 return;
5219 }
5220
5221 mtx_assert(MNT_MTX(mp), MA_OWNED);
5222
5223 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5224 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5225 MNT_REL(mp);
5226 MNT_IUNLOCK(mp);
5227 free(*mvp, M_VNODE_MARKER);
5228 *mvp = NULL;
5229 }
5230
5231 /*
5232 * These are helper functions for filesystems to traverse their
5233 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
5234 */
5235 static void
5236 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
5237 {
5238
5239 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5240
5241 MNT_ILOCK(mp);
5242 MNT_REL(mp);
5243 MNT_IUNLOCK(mp);
5244 free(*mvp, M_VNODE_MARKER);
5245 *mvp = NULL;
5246 }
5247
5248 static struct vnode *
5249 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
5250 {
5251 struct vnode *vp, *nvp;
5252
5253 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
5254 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5255 restart:
5256 vp = TAILQ_NEXT(*mvp, v_actfreelist);
5257 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
5258 while (vp != NULL) {
5259 if (vp->v_type == VMARKER) {
5260 vp = TAILQ_NEXT(vp, v_actfreelist);
5261 continue;
5262 }
5263 if (!VI_TRYLOCK(vp)) {
5264 if (mp_ncpus == 1 || should_yield()) {
5265 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
5266 mtx_unlock(&vnode_free_list_mtx);
5267 pause("vnacti", 1);
5268 mtx_lock(&vnode_free_list_mtx);
5269 goto restart;
5270 }
5271 continue;
5272 }
5273 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
5274 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
5275 ("alien vnode on the active list %p %p", vp, mp));
5276 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0)
5277 break;
5278 nvp = TAILQ_NEXT(vp, v_actfreelist);
5279 VI_UNLOCK(vp);
5280 vp = nvp;
5281 }
5282
5283 /* Check if we are done */
5284 if (vp == NULL) {
5285 mtx_unlock(&vnode_free_list_mtx);
5286 mnt_vnode_markerfree_active(mvp, mp);
5287 return (NULL);
5288 }
5289 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
5290 mtx_unlock(&vnode_free_list_mtx);
5291 ASSERT_VI_LOCKED(vp, "active iter");
5292 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp));
5293 return (vp);
5294 }
5295
5296 struct vnode *
5297 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
5298 {
5299
5300 if (should_yield())
5301 kern_yield(PRI_USER);
5302 mtx_lock(&vnode_free_list_mtx);
5303 return (mnt_vnode_next_active(mvp, mp));
5304 }
5305
5306 struct vnode *
5307 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
5308 {
5309 struct vnode *vp;
5310
5311 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
5312 MNT_ILOCK(mp);
5313 MNT_REF(mp);
5314 MNT_IUNLOCK(mp);
5315 (*mvp)->v_type = VMARKER;
5316 (*mvp)->v_mount = mp;
5317
5318 mtx_lock(&vnode_free_list_mtx);
5319 vp = TAILQ_FIRST(&mp->mnt_activevnodelist);
5320 if (vp == NULL) {
5321 mtx_unlock(&vnode_free_list_mtx);
5322 mnt_vnode_markerfree_active(mvp, mp);
5323 return (NULL);
5324 }
5325 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
5326 return (mnt_vnode_next_active(mvp, mp));
5327 }
5328
5329 void
5330 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
5331 {
5332
5333 if (*mvp == NULL)
5334 return;
5335
5336 mtx_lock(&vnode_free_list_mtx);
5337 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
5338 mtx_unlock(&vnode_free_list_mtx);
5339 mnt_vnode_markerfree_active(mvp, mp);
5340 }
Cache object: a2d4142d6330e4d58769489b90b3e044
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