2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
40 * External virtual filesystem routines
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
47 #include "opt_watchdog.h"
49 #include <sys/param.h>
50 #include <sys/systm.h>
53 #include <sys/capsicum.h>
54 #include <sys/condvar.h>
56 #include <sys/counter.h>
57 #include <sys/dirent.h>
58 #include <sys/event.h>
59 #include <sys/eventhandler.h>
60 #include <sys/extattr.h>
62 #include <sys/fcntl.h>
65 #include <sys/kernel.h>
66 #include <sys/kthread.h>
68 #include <sys/lockf.h>
69 #include <sys/malloc.h>
70 #include <sys/mount.h>
71 #include <sys/namei.h>
72 #include <sys/pctrie.h>
74 #include <sys/reboot.h>
75 #include <sys/refcount.h>
76 #include <sys/rwlock.h>
77 #include <sys/sched.h>
78 #include <sys/sleepqueue.h>
81 #include <sys/sysctl.h>
82 #include <sys/syslog.h>
83 #include <sys/vmmeter.h>
84 #include <sys/vnode.h>
85 #include <sys/watchdog.h>
87 #include <machine/stdarg.h>
89 #include <security/mac/mac_framework.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_extern.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_page.h>
97 #include <vm/vm_kern.h>
104 static void delmntque(struct vnode *vp);
105 static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
106 int slpflag, int slptimeo);
107 static void syncer_shutdown(void *arg, int howto);
108 static int vtryrecycle(struct vnode *vp);
109 static void v_init_counters(struct vnode *);
110 static void v_incr_devcount(struct vnode *);
111 static void v_decr_devcount(struct vnode *);
112 static void vgonel(struct vnode *);
113 static void vfs_knllock(void *arg);
114 static void vfs_knlunlock(void *arg);
115 static void vfs_knl_assert_locked(void *arg);
116 static void vfs_knl_assert_unlocked(void *arg);
117 static void vnlru_return_batches(struct vfsops *mnt_op);
118 static void destroy_vpollinfo(struct vpollinfo *vi);
119 static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
120 daddr_t startlbn, daddr_t endlbn);
123 * These fences are intended for cases where some synchronization is
124 * needed between access of v_iflags and lockless vnode refcount (v_holdcnt
125 * and v_usecount) updates. Access to v_iflags is generally synchronized
126 * by the interlock, but we have some internal assertions that check vnode
127 * flags without acquiring the lock. Thus, these fences are INVARIANTS-only
131 #define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq()
132 #define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel()
134 #define VNODE_REFCOUNT_FENCE_ACQ()
135 #define VNODE_REFCOUNT_FENCE_REL()
139 * Number of vnodes in existence. Increased whenever getnewvnode()
140 * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
142 static unsigned long numvnodes;
144 SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
145 "Number of vnodes in existence");
147 static counter_u64_t vnodes_created;
148 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
149 "Number of vnodes created by getnewvnode");
151 static u_long mnt_free_list_batch = 128;
152 SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW,
153 &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list");
156 * Conversion tables for conversion from vnode types to inode formats
159 enum vtype iftovt_tab[16] = {
160 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
161 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
163 int vttoif_tab[10] = {
164 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
165 S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
169 * List of vnodes that are ready for recycling.
171 static TAILQ_HEAD(freelst, vnode) vnode_free_list;
174 * "Free" vnode target. Free vnodes are rarely completely free, but are
175 * just ones that are cheap to recycle. Usually they are for files which
176 * have been stat'd but not read; these usually have inode and namecache
177 * data attached to them. This target is the preferred minimum size of a
178 * sub-cache consisting mostly of such files. The system balances the size
179 * of this sub-cache with its complement to try to prevent either from
180 * thrashing while the other is relatively inactive. The targets express
181 * a preference for the best balance.
183 * "Above" this target there are 2 further targets (watermarks) related
184 * to recyling of free vnodes. In the best-operating case, the cache is
185 * exactly full, the free list has size between vlowat and vhiwat above the
186 * free target, and recycling from it and normal use maintains this state.
187 * Sometimes the free list is below vlowat or even empty, but this state
188 * is even better for immediate use provided the cache is not full.
189 * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
190 * ones) to reach one of these states. The watermarks are currently hard-
191 * coded as 4% and 9% of the available space higher. These and the default
192 * of 25% for wantfreevnodes are too large if the memory size is large.
193 * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
194 * whenever vnlru_proc() becomes active.
196 static u_long wantfreevnodes;
197 SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW,
198 &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes");
199 static u_long freevnodes;
200 SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD,
201 &freevnodes, 0, "Number of \"free\" vnodes");
203 static counter_u64_t recycles_count;
204 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count,
205 "Number of vnodes recycled to meet vnode cache targets");
208 * Various variables used for debugging the new implementation of
210 * XXX these are probably of (very) limited utility now.
212 static int reassignbufcalls;
213 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW | CTLFLAG_STATS,
214 &reassignbufcalls, 0, "Number of calls to reassignbuf");
216 static counter_u64_t free_owe_inact;
217 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact,
218 "Number of times free vnodes kept on active list due to VFS "
219 "owing inactivation");
221 /* To keep more than one thread at a time from running vfs_getnewfsid */
222 static struct mtx mntid_mtx;
225 * Lock for any access to the following:
230 static struct mtx vnode_free_list_mtx;
232 /* Publicly exported FS */
233 struct nfs_public nfs_pub;
235 static uma_zone_t buf_trie_zone;
237 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
238 static uma_zone_t vnode_zone;
239 static uma_zone_t vnodepoll_zone;
242 * The workitem queue.
244 * It is useful to delay writes of file data and filesystem metadata
245 * for tens of seconds so that quickly created and deleted files need
246 * not waste disk bandwidth being created and removed. To realize this,
247 * we append vnodes to a "workitem" queue. When running with a soft
248 * updates implementation, most pending metadata dependencies should
249 * not wait for more than a few seconds. Thus, mounted on block devices
250 * are delayed only about a half the time that file data is delayed.
251 * Similarly, directory updates are more critical, so are only delayed
252 * about a third the time that file data is delayed. Thus, there are
253 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
254 * one each second (driven off the filesystem syncer process). The
255 * syncer_delayno variable indicates the next queue that is to be processed.
256 * Items that need to be processed soon are placed in this queue:
258 * syncer_workitem_pending[syncer_delayno]
260 * A delay of fifteen seconds is done by placing the request fifteen
261 * entries later in the queue:
263 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
266 static int syncer_delayno;
267 static long syncer_mask;
268 LIST_HEAD(synclist, bufobj);
269 static struct synclist *syncer_workitem_pending;
271 * The sync_mtx protects:
276 * syncer_workitem_pending
277 * syncer_worklist_len
280 static struct mtx sync_mtx;
281 static struct cv sync_wakeup;
283 #define SYNCER_MAXDELAY 32
284 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
285 static int syncdelay = 30; /* max time to delay syncing data */
286 static int filedelay = 30; /* time to delay syncing files */
287 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
288 "Time to delay syncing files (in seconds)");
289 static int dirdelay = 29; /* time to delay syncing directories */
290 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
291 "Time to delay syncing directories (in seconds)");
292 static int metadelay = 28; /* time to delay syncing metadata */
293 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
294 "Time to delay syncing metadata (in seconds)");
295 static int rushjob; /* number of slots to run ASAP */
296 static int stat_rush_requests; /* number of times I/O speeded up */
297 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
298 "Number of times I/O speeded up (rush requests)");
301 * When shutting down the syncer, run it at four times normal speed.
303 #define SYNCER_SHUTDOWN_SPEEDUP 4
304 static int sync_vnode_count;
305 static int syncer_worklist_len;
306 static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
309 /* Target for maximum number of vnodes. */
311 static int gapvnodes; /* gap between wanted and desired */
312 static int vhiwat; /* enough extras after expansion */
313 static int vlowat; /* minimal extras before expansion */
314 static int vstir; /* nonzero to stir non-free vnodes */
315 static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
318 sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS)
320 int error, old_desiredvnodes;
322 old_desiredvnodes = desiredvnodes;
323 if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0)
325 if (old_desiredvnodes != desiredvnodes) {
326 wantfreevnodes = desiredvnodes / 4;
327 /* XXX locking seems to be incomplete. */
328 vfs_hash_changesize(desiredvnodes);
329 cache_changesize(desiredvnodes);
334 SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
335 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0,
336 sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes");
337 SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
338 &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)");
339 static int vnlru_nowhere;
340 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
341 &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
344 sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
349 unsigned long ndflags;
352 if (req->newptr == NULL)
354 if (req->newlen >= PATH_MAX)
357 buf = malloc(PATH_MAX, M_TEMP, M_WAITOK);
358 error = SYSCTL_IN(req, buf, req->newlen);
362 buf[req->newlen] = '\0';
364 ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME;
365 NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread);
366 if ((error = namei(&nd)) != 0)
370 if ((vp->v_iflag & VI_DOOMED) != 0) {
372 * This vnode is being recycled. Return != 0 to let the caller
373 * know that the sysctl had no effect. Return EAGAIN because a
374 * subsequent call will likely succeed (since namei will create
375 * a new vnode if necessary)
381 counter_u64_add(recycles_count, 1);
391 sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS)
393 struct thread *td = curthread;
399 if (req->newptr == NULL)
402 error = sysctl_handle_int(oidp, &fd, 0, req);
405 error = getvnode(curthread, fd, &cap_fcntl_rights, &fp);
410 error = vn_lock(vp, LK_EXCLUSIVE);
414 counter_u64_add(recycles_count, 1);
422 SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
423 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
424 sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
425 SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode,
426 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
427 sysctl_ftry_reclaim_vnode, "I",
428 "Try to reclaim a vnode by its file descriptor");
430 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
434 * Support for the bufobj clean & dirty pctrie.
437 buf_trie_alloc(struct pctrie *ptree)
440 return uma_zalloc(buf_trie_zone, M_NOWAIT);
444 buf_trie_free(struct pctrie *ptree, void *node)
447 uma_zfree(buf_trie_zone, node);
449 PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
452 * Initialize the vnode management data structures.
454 * Reevaluate the following cap on the number of vnodes after the physical
455 * memory size exceeds 512GB. In the limit, as the physical memory size
456 * grows, the ratio of the memory size in KB to vnodes approaches 64:1.
458 #ifndef MAXVNODES_MAX
459 #define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */
463 * Initialize a vnode as it first enters the zone.
466 vnode_init(void *mem, int size, int flags)
475 vp->v_vnlock = &vp->v_lock;
476 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
478 * By default, don't allow shared locks unless filesystems opt-in.
480 lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
481 LK_NOSHARE | LK_IS_VNODE);
485 bufobj_init(&vp->v_bufobj, vp);
487 * Initialize namecache.
489 LIST_INIT(&vp->v_cache_src);
490 TAILQ_INIT(&vp->v_cache_dst);
492 * Initialize rangelocks.
494 rangelock_init(&vp->v_rl);
499 * Free a vnode when it is cleared from the zone.
502 vnode_fini(void *mem, int size)
508 rangelock_destroy(&vp->v_rl);
509 lockdestroy(vp->v_vnlock);
510 mtx_destroy(&vp->v_interlock);
512 rw_destroy(BO_LOCKPTR(bo));
516 * Provide the size of NFS nclnode and NFS fh for calculation of the
517 * vnode memory consumption. The size is specified directly to
518 * eliminate dependency on NFS-private header.
520 * Other filesystems may use bigger or smaller (like UFS and ZFS)
521 * private inode data, but the NFS-based estimation is ample enough.
522 * Still, we care about differences in the size between 64- and 32-bit
525 * Namecache structure size is heuristically
526 * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
529 #define NFS_NCLNODE_SZ (528 + 64)
532 #define NFS_NCLNODE_SZ (360 + 32)
537 vntblinit(void *dummy __unused)
540 int physvnodes, virtvnodes;
543 * Desiredvnodes is a function of the physical memory size and the
544 * kernel's heap size. Generally speaking, it scales with the
545 * physical memory size. The ratio of desiredvnodes to the physical
546 * memory size is 1:16 until desiredvnodes exceeds 98,304.
548 * marginal ratio of desiredvnodes to the physical memory size is
549 * 1:64. However, desiredvnodes is limited by the kernel's heap
550 * size. The memory required by desiredvnodes vnodes and vm objects
551 * must not exceed 1/10th of the kernel's heap size.
553 physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
554 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
555 virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
556 sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
557 desiredvnodes = min(physvnodes, virtvnodes);
558 if (desiredvnodes > MAXVNODES_MAX) {
560 printf("Reducing kern.maxvnodes %d -> %d\n",
561 desiredvnodes, MAXVNODES_MAX);
562 desiredvnodes = MAXVNODES_MAX;
564 wantfreevnodes = desiredvnodes / 4;
565 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
566 TAILQ_INIT(&vnode_free_list);
567 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
568 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
569 vnode_init, vnode_fini, UMA_ALIGN_PTR, 0);
570 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
571 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
573 * Preallocate enough nodes to support one-per buf so that
574 * we can not fail an insert. reassignbuf() callers can not
575 * tolerate the insertion failure.
577 buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
578 NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
579 UMA_ZONE_NOFREE | UMA_ZONE_VM);
580 uma_prealloc(buf_trie_zone, nbuf);
582 vnodes_created = counter_u64_alloc(M_WAITOK);
583 recycles_count = counter_u64_alloc(M_WAITOK);
584 free_owe_inact = counter_u64_alloc(M_WAITOK);
587 * Initialize the filesystem syncer.
589 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
591 syncer_maxdelay = syncer_mask + 1;
592 mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
593 cv_init(&sync_wakeup, "syncer");
594 for (i = 1; i <= sizeof(struct vnode); i <<= 1)
598 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
602 * Mark a mount point as busy. Used to synchronize access and to delay
603 * unmounting. Eventually, mountlist_mtx is not released on failure.
605 * vfs_busy() is a custom lock, it can block the caller.
606 * vfs_busy() only sleeps if the unmount is active on the mount point.
607 * For a mountpoint mp, vfs_busy-enforced lock is before lock of any
608 * vnode belonging to mp.
610 * Lookup uses vfs_busy() to traverse mount points.
612 * / vnode lock A / vnode lock (/var) D
613 * /var vnode lock B /log vnode lock(/var/log) E
614 * vfs_busy lock C vfs_busy lock F
616 * Within each file system, the lock order is C->A->B and F->D->E.
618 * When traversing across mounts, the system follows that lock order:
624 * The lookup() process for namei("/var") illustrates the process:
625 * VOP_LOOKUP() obtains B while A is held
626 * vfs_busy() obtains a shared lock on F while A and B are held
627 * vput() releases lock on B
628 * vput() releases lock on A
629 * VFS_ROOT() obtains lock on D while shared lock on F is held
630 * vfs_unbusy() releases shared lock on F
631 * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
632 * Attempt to lock A (instead of vp_crossmp) while D is held would
633 * violate the global order, causing deadlocks.
635 * dounmount() locks B while F is drained.
638 vfs_busy(struct mount *mp, int flags)
641 MPASS((flags & ~MBF_MASK) == 0);
642 CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
644 if (vfs_op_thread_enter(mp)) {
645 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
646 MPASS((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0);
647 MPASS((mp->mnt_kern_flag & MNTK_REFEXPIRE) == 0);
648 vfs_mp_count_add_pcpu(mp, ref, 1);
649 vfs_mp_count_add_pcpu(mp, lockref, 1);
650 vfs_op_thread_exit(mp);
651 if (flags & MBF_MNTLSTLOCK)
652 mtx_unlock(&mountlist_mtx);
657 vfs_assert_mount_counters(mp);
660 * If mount point is currently being unmounted, sleep until the
661 * mount point fate is decided. If thread doing the unmounting fails,
662 * it will clear MNTK_UNMOUNT flag before waking us up, indicating
663 * that this mount point has survived the unmount attempt and vfs_busy
664 * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
665 * flag in addition to MNTK_UNMOUNT, indicating that mount point is
666 * about to be really destroyed. vfs_busy needs to release its
667 * reference on the mount point in this case and return with ENOENT,
668 * telling the caller that mount mount it tried to busy is no longer
671 while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
672 if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
675 CTR1(KTR_VFS, "%s: failed busying before sleeping",
679 if (flags & MBF_MNTLSTLOCK)
680 mtx_unlock(&mountlist_mtx);
681 mp->mnt_kern_flag |= MNTK_MWAIT;
682 msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
683 if (flags & MBF_MNTLSTLOCK)
684 mtx_lock(&mountlist_mtx);
687 if (flags & MBF_MNTLSTLOCK)
688 mtx_unlock(&mountlist_mtx);
695 * Free a busy filesystem.
698 vfs_unbusy(struct mount *mp)
702 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
704 if (vfs_op_thread_enter(mp)) {
705 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
706 vfs_mp_count_sub_pcpu(mp, lockref, 1);
707 vfs_mp_count_sub_pcpu(mp, ref, 1);
708 vfs_op_thread_exit(mp);
713 vfs_assert_mount_counters(mp);
715 c = --mp->mnt_lockref;
716 if (mp->mnt_vfs_ops == 0) {
717 MPASS((mp->mnt_kern_flag & MNTK_DRAINING) == 0);
722 vfs_dump_mount_counters(mp);
723 if (c == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
724 MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
725 CTR1(KTR_VFS, "%s: waking up waiters", __func__);
726 mp->mnt_kern_flag &= ~MNTK_DRAINING;
727 wakeup(&mp->mnt_lockref);
733 * Lookup a mount point by filesystem identifier.
736 vfs_getvfs(fsid_t *fsid)
740 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
741 mtx_lock(&mountlist_mtx);
742 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
743 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
744 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
746 mtx_unlock(&mountlist_mtx);
750 mtx_unlock(&mountlist_mtx);
751 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
752 return ((struct mount *) 0);
756 * Lookup a mount point by filesystem identifier, busying it before
759 * To avoid congestion on mountlist_mtx, implement simple direct-mapped
760 * cache for popular filesystem identifiers. The cache is lockess, using
761 * the fact that struct mount's are never freed. In worst case we may
762 * get pointer to unmounted or even different filesystem, so we have to
763 * check what we got, and go slow way if so.
766 vfs_busyfs(fsid_t *fsid)
768 #define FSID_CACHE_SIZE 256
769 typedef struct mount * volatile vmp_t;
770 static vmp_t cache[FSID_CACHE_SIZE];
775 CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
776 hash = fsid->val[0] ^ fsid->val[1];
777 hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
780 mp->mnt_stat.f_fsid.val[0] != fsid->val[0] ||
781 mp->mnt_stat.f_fsid.val[1] != fsid->val[1])
783 if (vfs_busy(mp, 0) != 0) {
787 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
788 mp->mnt_stat.f_fsid.val[1] == fsid->val[1])
794 mtx_lock(&mountlist_mtx);
795 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
796 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
797 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
798 error = vfs_busy(mp, MBF_MNTLSTLOCK);
801 mtx_unlock(&mountlist_mtx);
808 CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
809 mtx_unlock(&mountlist_mtx);
810 return ((struct mount *) 0);
814 * Check if a user can access privileged mount options.
817 vfs_suser(struct mount *mp, struct thread *td)
821 if (jailed(td->td_ucred)) {
823 * If the jail of the calling thread lacks permission for
824 * this type of file system, deny immediately.
826 if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag))
830 * If the file system was mounted outside the jail of the
831 * calling thread, deny immediately.
833 if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
838 * If file system supports delegated administration, we don't check
839 * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
840 * by the file system itself.
841 * If this is not the user that did original mount, we check for
842 * the PRIV_VFS_MOUNT_OWNER privilege.
844 if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
845 mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
846 if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
853 * Get a new unique fsid. Try to make its val[0] unique, since this value
854 * will be used to create fake device numbers for stat(). Also try (but
855 * not so hard) make its val[0] unique mod 2^16, since some emulators only
856 * support 16-bit device numbers. We end up with unique val[0]'s for the
857 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
859 * Keep in mind that several mounts may be running in parallel. Starting
860 * the search one past where the previous search terminated is both a
861 * micro-optimization and a defense against returning the same fsid to
865 vfs_getnewfsid(struct mount *mp)
867 static uint16_t mntid_base;
872 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
873 mtx_lock(&mntid_mtx);
874 mtype = mp->mnt_vfc->vfc_typenum;
875 tfsid.val[1] = mtype;
876 mtype = (mtype & 0xFF) << 24;
878 tfsid.val[0] = makedev(255,
879 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
881 if ((nmp = vfs_getvfs(&tfsid)) == NULL)
885 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
886 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
887 mtx_unlock(&mntid_mtx);
891 * Knob to control the precision of file timestamps:
893 * 0 = seconds only; nanoseconds zeroed.
894 * 1 = seconds and nanoseconds, accurate within 1/HZ.
895 * 2 = seconds and nanoseconds, truncated to microseconds.
896 * >=3 = seconds and nanoseconds, maximum precision.
898 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
900 static int timestamp_precision = TSP_USEC;
901 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
902 ×tamp_precision, 0, "File timestamp precision (0: seconds, "
903 "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, "
904 "3+: sec + ns (max. precision))");
907 * Get a current timestamp.
910 vfs_timestamp(struct timespec *tsp)
914 switch (timestamp_precision) {
916 tsp->tv_sec = time_second;
924 TIMEVAL_TO_TIMESPEC(&tv, tsp);
934 * Set vnode attributes to VNOVAL
937 vattr_null(struct vattr *vap)
941 vap->va_size = VNOVAL;
942 vap->va_bytes = VNOVAL;
943 vap->va_mode = VNOVAL;
944 vap->va_nlink = VNOVAL;
945 vap->va_uid = VNOVAL;
946 vap->va_gid = VNOVAL;
947 vap->va_fsid = VNOVAL;
948 vap->va_fileid = VNOVAL;
949 vap->va_blocksize = VNOVAL;
950 vap->va_rdev = VNOVAL;
951 vap->va_atime.tv_sec = VNOVAL;
952 vap->va_atime.tv_nsec = VNOVAL;
953 vap->va_mtime.tv_sec = VNOVAL;
954 vap->va_mtime.tv_nsec = VNOVAL;
955 vap->va_ctime.tv_sec = VNOVAL;
956 vap->va_ctime.tv_nsec = VNOVAL;
957 vap->va_birthtime.tv_sec = VNOVAL;
958 vap->va_birthtime.tv_nsec = VNOVAL;
959 vap->va_flags = VNOVAL;
960 vap->va_gen = VNOVAL;
965 * This routine is called when we have too many vnodes. It attempts
966 * to free <count> vnodes and will potentially free vnodes that still
967 * have VM backing store (VM backing store is typically the cause
968 * of a vnode blowout so we want to do this). Therefore, this operation
969 * is not considered cheap.
971 * A number of conditions may prevent a vnode from being reclaimed.
972 * the buffer cache may have references on the vnode, a directory
973 * vnode may still have references due to the namei cache representing
974 * underlying files, or the vnode may be in active use. It is not
975 * desirable to reuse such vnodes. These conditions may cause the
976 * number of vnodes to reach some minimum value regardless of what
977 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
979 * @param mp Try to reclaim vnodes from this mountpoint
980 * @param reclaim_nc_src Only reclaim directories with outgoing namecache
981 * entries if this argument is strue
982 * @param trigger Only reclaim vnodes with fewer than this many resident
984 * @return The number of vnodes that were reclaimed.
987 vlrureclaim(struct mount *mp, bool reclaim_nc_src, int trigger)
990 int count, done, target;
993 vn_start_write(NULL, &mp, V_WAIT);
995 count = mp->mnt_nvnodelistsize;
996 target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1);
997 target = target / 10 + 1;
998 while (count != 0 && done < target) {
999 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
1000 while (vp != NULL && vp->v_type == VMARKER)
1001 vp = TAILQ_NEXT(vp, v_nmntvnodes);
1005 * XXX LRU is completely broken for non-free vnodes. First
1006 * by calling here in mountpoint order, then by moving
1007 * unselected vnodes to the end here, and most grossly by
1008 * removing the vlruvp() function that was supposed to
1009 * maintain the order. (This function was born broken
1010 * since syncer problems prevented it doing anything.) The
1011 * order is closer to LRC (C = Created).
1013 * LRU reclaiming of vnodes seems to have last worked in
1014 * FreeBSD-3 where LRU wasn't mentioned under any spelling.
1015 * Then there was no hold count, and inactive vnodes were
1016 * simply put on the free list in LRU order. The separate
1017 * lists also break LRU. We prefer to reclaim from the
1018 * free list for technical reasons. This tends to thrash
1019 * the free list to keep very unrecently used held vnodes.
1020 * The problem is mitigated by keeping the free list large.
1022 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1023 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1025 if (!VI_TRYLOCK(vp))
1028 * If it's been deconstructed already, it's still
1029 * referenced, or it exceeds the trigger, skip it.
1030 * Also skip free vnodes. We are trying to make space
1031 * to expand the free list, not reduce it.
1033 if (vp->v_usecount ||
1034 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1035 ((vp->v_iflag & VI_FREE) != 0) ||
1036 (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
1037 vp->v_object->resident_page_count > trigger)) {
1043 if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
1045 goto next_iter_mntunlocked;
1049 * v_usecount may have been bumped after VOP_LOCK() dropped
1050 * the vnode interlock and before it was locked again.
1052 * It is not necessary to recheck VI_DOOMED because it can
1053 * only be set by another thread that holds both the vnode
1054 * lock and vnode interlock. If another thread has the
1055 * vnode lock before we get to VOP_LOCK() and obtains the
1056 * vnode interlock after VOP_LOCK() drops the vnode
1057 * interlock, the other thread will be unable to drop the
1058 * vnode lock before our VOP_LOCK() call fails.
1060 if (vp->v_usecount ||
1061 (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
1062 (vp->v_iflag & VI_FREE) != 0 ||
1063 (vp->v_object != NULL &&
1064 vp->v_object->resident_page_count > trigger)) {
1067 goto next_iter_mntunlocked;
1069 KASSERT((vp->v_iflag & VI_DOOMED) == 0,
1070 ("VI_DOOMED unexpectedly detected in vlrureclaim()"));
1071 counter_u64_add(recycles_count, 1);
1076 next_iter_mntunlocked:
1077 if (!should_yield())
1081 if (!should_yield())
1085 kern_yield(PRI_USER);
1090 vn_finished_write(mp);
1094 static int max_vnlru_free = 10000; /* limit on vnode free requests per call */
1095 SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free,
1097 "limit on vnode free requests per call to the vnlru_free routine");
1100 * Attempt to reduce the free list by the requested amount.
1103 vnlru_free_locked(int count, struct vfsops *mnt_op)
1109 tried_batches = false;
1110 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
1111 if (count > max_vnlru_free)
1112 count = max_vnlru_free;
1113 for (; count > 0; count--) {
1114 vp = TAILQ_FIRST(&vnode_free_list);
1116 * The list can be modified while the free_list_mtx
1117 * has been dropped and vp could be NULL here.
1122 mtx_unlock(&vnode_free_list_mtx);
1123 vnlru_return_batches(mnt_op);
1124 tried_batches = true;
1125 mtx_lock(&vnode_free_list_mtx);
1129 VNASSERT(vp->v_op != NULL, vp,
1130 ("vnlru_free: vnode already reclaimed."));
1131 KASSERT((vp->v_iflag & VI_FREE) != 0,
1132 ("Removing vnode not on freelist"));
1133 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1134 ("Mangling active vnode"));
1135 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
1138 * Don't recycle if our vnode is from different type
1139 * of mount point. Note that mp is type-safe, the
1140 * check does not reach unmapped address even if
1141 * vnode is reclaimed.
1142 * Don't recycle if we can't get the interlock without
1145 if ((mnt_op != NULL && (mp = vp->v_mount) != NULL &&
1146 mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) {
1147 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
1150 VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0,
1151 vp, ("vp inconsistent on freelist"));
1154 * The clear of VI_FREE prevents activation of the
1155 * vnode. There is no sense in putting the vnode on
1156 * the mount point active list, only to remove it
1157 * later during recycling. Inline the relevant part
1158 * of vholdl(), to avoid triggering assertions or
1162 vp->v_iflag &= ~VI_FREE;
1163 VNODE_REFCOUNT_FENCE_REL();
1164 refcount_acquire(&vp->v_holdcnt);
1166 mtx_unlock(&vnode_free_list_mtx);
1170 * If the recycled succeeded this vdrop will actually free
1171 * the vnode. If not it will simply place it back on
1175 mtx_lock(&vnode_free_list_mtx);
1180 vnlru_free(int count, struct vfsops *mnt_op)
1183 mtx_lock(&vnode_free_list_mtx);
1184 vnlru_free_locked(count, mnt_op);
1185 mtx_unlock(&vnode_free_list_mtx);
1189 /* XXX some names and initialization are bad for limits and watermarks. */
1195 gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
1196 vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
1197 vlowat = vhiwat / 2;
1198 if (numvnodes > desiredvnodes)
1200 space = desiredvnodes - numvnodes;
1201 if (freevnodes > wantfreevnodes)
1202 space += freevnodes - wantfreevnodes;
1207 vnlru_return_batch_locked(struct mount *mp)
1211 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
1213 if (mp->mnt_tmpfreevnodelistsize == 0)
1216 TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) {
1217 VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp,
1218 ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist"));
1219 vp->v_mflag &= ~VMP_TMPMNTFREELIST;
1221 mtx_lock(&vnode_free_list_mtx);
1222 TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist);
1223 freevnodes += mp->mnt_tmpfreevnodelistsize;
1224 mtx_unlock(&vnode_free_list_mtx);
1225 mp->mnt_tmpfreevnodelistsize = 0;
1229 vnlru_return_batch(struct mount *mp)
1232 mtx_lock(&mp->mnt_listmtx);
1233 vnlru_return_batch_locked(mp);
1234 mtx_unlock(&mp->mnt_listmtx);
1238 vnlru_return_batches(struct vfsops *mnt_op)
1240 struct mount *mp, *nmp;
1243 mtx_lock(&mountlist_mtx);
1244 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1245 need_unbusy = false;
1246 if (mnt_op != NULL && mp->mnt_op != mnt_op)
1248 if (mp->mnt_tmpfreevnodelistsize == 0)
1250 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) {
1251 vnlru_return_batch(mp);
1253 mtx_lock(&mountlist_mtx);
1256 nmp = TAILQ_NEXT(mp, mnt_list);
1260 mtx_unlock(&mountlist_mtx);
1264 * Attempt to recycle vnodes in a context that is always safe to block.
1265 * Calling vlrurecycle() from the bowels of filesystem code has some
1266 * interesting deadlock problems.
1268 static struct proc *vnlruproc;
1269 static int vnlruproc_sig;
1274 struct mount *mp, *nmp;
1275 unsigned long onumvnodes;
1276 int done, force, trigger, usevnodes, vsp;
1277 bool reclaim_nc_src;
1279 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
1280 SHUTDOWN_PRI_FIRST);
1284 kproc_suspend_check(vnlruproc);
1285 mtx_lock(&vnode_free_list_mtx);
1287 * If numvnodes is too large (due to desiredvnodes being
1288 * adjusted using its sysctl, or emergency growth), first
1289 * try to reduce it by discarding from the free list.
1291 if (numvnodes > desiredvnodes)
1292 vnlru_free_locked(numvnodes - desiredvnodes, NULL);
1294 * Sleep if the vnode cache is in a good state. This is
1295 * when it is not over-full and has space for about a 4%
1296 * or 9% expansion (by growing its size or inexcessively
1297 * reducing its free list). Otherwise, try to reclaim
1298 * space for a 10% expansion.
1300 if (vstir && force == 0) {
1305 if (vsp >= vlowat && force == 0) {
1307 wakeup(&vnlruproc_sig);
1308 msleep(vnlruproc, &vnode_free_list_mtx,
1309 PVFS|PDROP, "vlruwt", hz);
1312 mtx_unlock(&vnode_free_list_mtx);
1314 onumvnodes = numvnodes;
1316 * Calculate parameters for recycling. These are the same
1317 * throughout the loop to give some semblance of fairness.
1318 * The trigger point is to avoid recycling vnodes with lots
1319 * of resident pages. We aren't trying to free memory; we
1320 * are trying to recycle or at least free vnodes.
1322 if (numvnodes <= desiredvnodes)
1323 usevnodes = numvnodes - freevnodes;
1325 usevnodes = numvnodes;
1329 * The trigger value is is chosen to give a conservatively
1330 * large value to ensure that it alone doesn't prevent
1331 * making progress. The value can easily be so large that
1332 * it is effectively infinite in some congested and
1333 * misconfigured cases, and this is necessary. Normally
1334 * it is about 8 to 100 (pages), which is quite large.
1336 trigger = vm_cnt.v_page_count * 2 / usevnodes;
1338 trigger = vsmalltrigger;
1339 reclaim_nc_src = force >= 3;
1340 mtx_lock(&mountlist_mtx);
1341 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1342 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
1343 nmp = TAILQ_NEXT(mp, mnt_list);
1346 done += vlrureclaim(mp, reclaim_nc_src, trigger);
1347 mtx_lock(&mountlist_mtx);
1348 nmp = TAILQ_NEXT(mp, mnt_list);
1351 mtx_unlock(&mountlist_mtx);
1352 if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes)
1353 uma_reclaim(UMA_RECLAIM_DRAIN);
1355 if (force == 0 || force == 1) {
1365 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
1367 kern_yield(PRI_USER);
1369 * After becoming active to expand above low water, keep
1370 * active until above high water.
1373 force = vsp < vhiwat;
1377 static struct kproc_desc vnlru_kp = {
1382 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
1386 * Routines having to do with the management of the vnode table.
1390 * Try to recycle a freed vnode. We abort if anyone picks up a reference
1391 * before we actually vgone(). This function must be called with the vnode
1392 * held to prevent the vnode from being returned to the free list midway
1396 vtryrecycle(struct vnode *vp)
1400 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
1401 VNASSERT(vp->v_holdcnt, vp,
1402 ("vtryrecycle: Recycling vp %p without a reference.", vp));
1404 * This vnode may found and locked via some other list, if so we
1405 * can't recycle it yet.
1407 if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
1409 "%s: impossible to recycle, vp %p lock is already held",
1411 return (EWOULDBLOCK);
1414 * Don't recycle if its filesystem is being suspended.
1416 if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
1419 "%s: impossible to recycle, cannot start the write for %p",
1424 * If we got this far, we need to acquire the interlock and see if
1425 * anyone picked up this vnode from another list. If not, we will
1426 * mark it with DOOMED via vgonel() so that anyone who does find it
1427 * will skip over it.
1430 if (vp->v_usecount) {
1433 vn_finished_write(vnmp);
1435 "%s: impossible to recycle, %p is already referenced",
1439 if ((vp->v_iflag & VI_DOOMED) == 0) {
1440 counter_u64_add(recycles_count, 1);
1445 vn_finished_write(vnmp);
1455 if (vsp < vlowat && vnlruproc_sig == 0) {
1462 * Wait if necessary for space for a new vnode.
1465 getnewvnode_wait(int suspended)
1468 mtx_assert(&vnode_free_list_mtx, MA_OWNED);
1469 if (numvnodes >= desiredvnodes) {
1472 * The file system is being suspended. We cannot
1473 * risk a deadlock here, so allow allocation of
1474 * another vnode even if this would give too many.
1478 if (vnlruproc_sig == 0) {
1479 vnlruproc_sig = 1; /* avoid unnecessary wakeups */
1482 msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
1485 /* Post-adjust like the pre-adjust in getnewvnode(). */
1486 if (numvnodes + 1 > desiredvnodes && freevnodes > 1)
1487 vnlru_free_locked(1, NULL);
1488 return (numvnodes >= desiredvnodes ? ENFILE : 0);
1492 * This hack is fragile, and probably not needed any more now that the
1493 * watermark handling works.
1496 getnewvnode_reserve(u_int count)
1500 /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */
1501 /* XXX no longer so quick, but this part is not racy. */
1502 mtx_lock(&vnode_free_list_mtx);
1503 if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes)
1504 vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes,
1505 freevnodes - wantfreevnodes), NULL);
1506 mtx_unlock(&vnode_free_list_mtx);
1509 /* First try to be quick and racy. */
1510 if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) {
1511 td->td_vp_reserv += count;
1512 vcheckspace(); /* XXX no longer so quick, but more racy */
1515 atomic_subtract_long(&numvnodes, count);
1517 mtx_lock(&vnode_free_list_mtx);
1519 if (getnewvnode_wait(0) == 0) {
1522 atomic_add_long(&numvnodes, 1);
1526 mtx_unlock(&vnode_free_list_mtx);
1530 * This hack is fragile, especially if desiredvnodes or wantvnodes are
1531 * misconfgured or changed significantly. Reducing desiredvnodes below
1532 * the reserved amount should cause bizarre behaviour like reducing it
1533 * below the number of active vnodes -- the system will try to reduce
1534 * numvnodes to match, but should fail, so the subtraction below should
1538 getnewvnode_drop_reserve(void)
1543 atomic_subtract_long(&numvnodes, td->td_vp_reserv);
1544 td->td_vp_reserv = 0;
1548 * Return the next vnode from the free list.
1551 getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
1556 struct lock_object *lo;
1557 static int cyclecount;
1560 CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
1563 if (td->td_vp_reserv > 0) {
1564 td->td_vp_reserv -= 1;
1567 mtx_lock(&vnode_free_list_mtx);
1568 if (numvnodes < desiredvnodes)
1570 else if (cyclecount++ >= freevnodes) {
1575 * Grow the vnode cache if it will not be above its target max
1576 * after growing. Otherwise, if the free list is nonempty, try
1577 * to reclaim 1 item from it before growing the cache (possibly
1578 * above its target max if the reclamation failed or is delayed).
1579 * Otherwise, wait for some space. In all cases, schedule
1580 * vnlru_proc() if we are getting short of space. The watermarks
1581 * should be chosen so that we never wait or even reclaim from
1582 * the free list to below its target minimum.
1584 if (numvnodes + 1 <= desiredvnodes)
1586 else if (freevnodes > 0)
1587 vnlru_free_locked(1, NULL);
1589 error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag &
1591 #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
1593 mtx_unlock(&vnode_free_list_mtx);
1599 atomic_add_long(&numvnodes, 1);
1600 mtx_unlock(&vnode_free_list_mtx);
1602 counter_u64_add(vnodes_created, 1);
1603 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK);
1605 * Locks are given the generic name "vnode" when created.
1606 * Follow the historic practice of using the filesystem
1607 * name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
1609 * Locks live in a witness group keyed on their name. Thus,
1610 * when a lock is renamed, it must also move from the witness
1611 * group of its old name to the witness group of its new name.
1613 * The change only needs to be made when the vnode moves
1614 * from one filesystem type to another. We ensure that each
1615 * filesystem use a single static name pointer for its tag so
1616 * that we can compare pointers rather than doing a strcmp().
1618 lo = &vp->v_vnlock->lock_object;
1619 if (lo->lo_name != tag) {
1621 WITNESS_DESTROY(lo);
1622 WITNESS_INIT(lo, tag);
1625 * By default, don't allow shared locks unless filesystems opt-in.
1627 vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
1629 * Finalize various vnode identity bits.
1631 KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
1632 KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
1633 KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
1637 v_init_counters(vp);
1638 vp->v_bufobj.bo_ops = &buf_ops_bio;
1640 if (mp == NULL && vops != &dead_vnodeops)
1641 printf("NULL mp in getnewvnode(9), tag %s\n", tag);
1645 if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
1646 mac_vnode_associate_singlelabel(mp, vp);
1649 vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
1650 if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
1651 vp->v_vflag |= VV_NOKNOTE;
1655 * For the filesystems which do not use vfs_hash_insert(),
1656 * still initialize v_hash to have vfs_hash_index() useful.
1657 * E.g., nullfs uses vfs_hash_index() on the lower vnode for
1660 vp->v_hash = (uintptr_t)vp >> vnsz2log;
1667 * Delete from old mount point vnode list, if on one.
1670 delmntque(struct vnode *vp)
1680 KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
1681 ("Active vnode list size %d > Vnode list size %d",
1682 mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
1683 active = vp->v_iflag & VI_ACTIVE;
1684 vp->v_iflag &= ~VI_ACTIVE;
1686 mtx_lock(&mp->mnt_listmtx);
1687 TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
1688 mp->mnt_activevnodelistsize--;
1689 mtx_unlock(&mp->mnt_listmtx);
1693 VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
1694 ("bad mount point vnode list size"));
1695 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1696 mp->mnt_nvnodelistsize--;
1702 insmntque_stddtr(struct vnode *vp, void *dtr_arg)
1706 vp->v_op = &dead_vnodeops;
1712 * Insert into list of vnodes for the new mount point, if available.
1715 insmntque1(struct vnode *vp, struct mount *mp,
1716 void (*dtr)(struct vnode *, void *), void *dtr_arg)
1719 KASSERT(vp->v_mount == NULL,
1720 ("insmntque: vnode already on per mount vnode list"));
1721 VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
1722 ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
1725 * We acquire the vnode interlock early to ensure that the
1726 * vnode cannot be recycled by another process releasing a
1727 * holdcnt on it before we get it on both the vnode list
1728 * and the active vnode list. The mount mutex protects only
1729 * manipulation of the vnode list and the vnode freelist
1730 * mutex protects only manipulation of the active vnode list.
1731 * Hence the need to hold the vnode interlock throughout.
1735 if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 &&
1736 ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
1737 mp->mnt_nvnodelistsize == 0)) &&
1738 (vp->v_vflag & VV_FORCEINSMQ) == 0) {
1747 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1748 VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
1749 ("neg mount point vnode list size"));
1750 mp->mnt_nvnodelistsize++;
1751 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
1752 ("Activating already active vnode"));
1753 vp->v_iflag |= VI_ACTIVE;
1754 mtx_lock(&mp->mnt_listmtx);
1755 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
1756 mp->mnt_activevnodelistsize++;
1757 mtx_unlock(&mp->mnt_listmtx);
1764 insmntque(struct vnode *vp, struct mount *mp)
1767 return (insmntque1(vp, mp, insmntque_stddtr, NULL));
1771 * Flush out and invalidate all buffers associated with a bufobj
1772 * Called with the underlying object locked.
1775 bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
1780 if (flags & V_SAVE) {
1781 error = bufobj_wwait(bo, slpflag, slptimeo);
1786 if (bo->bo_dirty.bv_cnt > 0) {
1788 if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
1791 * XXX We could save a lock/unlock if this was only
1792 * enabled under INVARIANTS
1795 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
1796 panic("vinvalbuf: dirty bufs");
1800 * If you alter this loop please notice that interlock is dropped and
1801 * reacquired in flushbuflist. Special care is needed to ensure that
1802 * no race conditions occur from this.
1805 error = flushbuflist(&bo->bo_clean,
1806 flags, bo, slpflag, slptimeo);
1807 if (error == 0 && !(flags & V_CLEANONLY))
1808 error = flushbuflist(&bo->bo_dirty,
1809 flags, bo, slpflag, slptimeo);
1810 if (error != 0 && error != EAGAIN) {
1814 } while (error != 0);
1817 * Wait for I/O to complete. XXX needs cleaning up. The vnode can
1818 * have write I/O in-progress but if there is a VM object then the
1819 * VM object can also have read-I/O in-progress.
1822 bufobj_wwait(bo, 0, 0);
1823 if ((flags & V_VMIO) == 0 && bo->bo_object != NULL) {
1825 vm_object_pip_wait_unlocked(bo->bo_object, "bovlbx");
1828 } while (bo->bo_numoutput > 0);
1832 * Destroy the copy in the VM cache, too.
1834 if (bo->bo_object != NULL &&
1835 (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
1836 VM_OBJECT_WLOCK(bo->bo_object);
1837 vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
1838 OBJPR_CLEANONLY : 0);
1839 VM_OBJECT_WUNLOCK(bo->bo_object);
1844 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO |
1845 V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 ||
1846 bo->bo_clean.bv_cnt > 0))
1847 panic("vinvalbuf: flush failed");
1848 if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
1849 bo->bo_dirty.bv_cnt > 0)
1850 panic("vinvalbuf: flush dirty failed");
1857 * Flush out and invalidate all buffers associated with a vnode.
1858 * Called with the underlying object locked.
1861 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
1864 CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
1865 ASSERT_VOP_LOCKED(vp, "vinvalbuf");
1866 if (vp->v_object != NULL && vp->v_object->handle != vp)
1868 return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
1872 * Flush out buffers on the specified list.
1876 flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
1879 struct buf *bp, *nbp;
1884 ASSERT_BO_WLOCKED(bo);
1887 TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
1889 * If we are flushing both V_NORMAL and V_ALT buffers then
1890 * do not skip any buffers. If we are flushing only V_NORMAL
1891 * buffers then skip buffers marked as BX_ALTDATA. If we are
1892 * flushing only V_ALT buffers then skip buffers not marked
1895 if (((flags & (V_NORMAL | V_ALT)) != (V_NORMAL | V_ALT)) &&
1896 (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA) != 0) ||
1897 ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0))) {
1901 lblkno = nbp->b_lblkno;
1902 xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
1905 error = BUF_TIMELOCK(bp,
1906 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
1907 "flushbuf", slpflag, slptimeo);
1910 return (error != ENOLCK ? error : EAGAIN);
1912 KASSERT(bp->b_bufobj == bo,
1913 ("bp %p wrong b_bufobj %p should be %p",
1914 bp, bp->b_bufobj, bo));
1916 * XXX Since there are no node locks for NFS, I
1917 * believe there is a slight chance that a delayed
1918 * write will occur while sleeping just above, so
1921 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
1924 bp->b_flags |= B_ASYNC;
1927 return (EAGAIN); /* XXX: why not loop ? */
1930 bp->b_flags |= (B_INVAL | B_RELBUF);
1931 bp->b_flags &= ~B_ASYNC;
1936 nbp = gbincore(bo, lblkno);
1937 if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
1939 break; /* nbp invalid */
1945 bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
1951 ASSERT_BO_LOCKED(bo);
1953 for (lblkno = startn;;) {
1955 bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
1956 if (bp == NULL || bp->b_lblkno >= endn ||
1957 bp->b_lblkno < startn)
1959 error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
1960 LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
1963 if (error == ENOLCK)
1967 KASSERT(bp->b_bufobj == bo,
1968 ("bp %p wrong b_bufobj %p should be %p",
1969 bp, bp->b_bufobj, bo));
1970 lblkno = bp->b_lblkno + 1;
1971 if ((bp->b_flags & B_MANAGED) == 0)
1973 bp->b_flags |= B_RELBUF;
1975 * In the VMIO case, use the B_NOREUSE flag to hint that the
1976 * pages backing each buffer in the range are unlikely to be
1977 * reused. Dirty buffers will have the hint applied once
1978 * they've been written.
1980 if ((bp->b_flags & B_VMIO) != 0)
1981 bp->b_flags |= B_NOREUSE;
1989 * Truncate a file's buffer and pages to a specified length. This
1990 * is in lieu of the old vinvalbuf mechanism, which performed unneeded
1994 vtruncbuf(struct vnode *vp, off_t length, int blksize)
1996 struct buf *bp, *nbp;
2000 CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__,
2001 vp, blksize, (uintmax_t)length);
2004 * Round up to the *next* lbn.
2006 startlbn = howmany(length, blksize);
2008 ASSERT_VOP_LOCKED(vp, "vtruncbuf");
2014 while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN)
2019 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2020 if (bp->b_lblkno > 0)
2023 * Since we hold the vnode lock this should only
2024 * fail if we're racing with the buf daemon.
2027 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2028 BO_LOCKPTR(bo)) == ENOLCK)
2029 goto restart_unlocked;
2031 VNASSERT((bp->b_flags & B_DELWRI), vp,
2032 ("buf(%p) on dirty queue without DELWRI", bp));
2041 bufobj_wwait(bo, 0, 0);
2043 vnode_pager_setsize(vp, length);
2049 * Invalidate the cached pages of a file's buffer within the range of block
2050 * numbers [startlbn, endlbn).
2053 v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn,
2059 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range");
2061 start = blksize * startlbn;
2062 end = blksize * endlbn;
2066 MPASS(blksize == bo->bo_bsize);
2068 while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN)
2072 vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1));
2076 v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo,
2077 daddr_t startlbn, daddr_t endlbn)
2079 struct buf *bp, *nbp;
2082 ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked");
2083 ASSERT_BO_LOCKED(bo);
2087 TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
2088 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
2091 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2092 BO_LOCKPTR(bo)) == ENOLCK) {
2098 bp->b_flags |= B_INVAL | B_RELBUF;
2099 bp->b_flags &= ~B_ASYNC;
2105 (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
2107 (nbp->b_flags & B_DELWRI) != 0))
2111 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2112 if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn)
2115 LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
2116 BO_LOCKPTR(bo)) == ENOLCK) {
2121 bp->b_flags |= B_INVAL | B_RELBUF;
2122 bp->b_flags &= ~B_ASYNC;
2128 (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
2129 (nbp->b_vp != vp) ||
2130 (nbp->b_flags & B_DELWRI) == 0))
2138 buf_vlist_remove(struct buf *bp)
2142 KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
2143 ASSERT_BO_WLOCKED(bp->b_bufobj);
2144 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
2145 (BX_VNDIRTY|BX_VNCLEAN),
2146 ("buf_vlist_remove: Buf %p is on two lists", bp));
2147 if (bp->b_xflags & BX_VNDIRTY)
2148 bv = &bp->b_bufobj->bo_dirty;
2150 bv = &bp->b_bufobj->bo_clean;
2151 BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
2152 TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
2154 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
2158 * Add the buffer to the sorted clean or dirty block list.
2160 * NOTE: xflags is passed as a constant, optimizing this inline function!
2163 buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
2169 ASSERT_BO_WLOCKED(bo);
2170 KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
2171 ("dead bo %p", bo));
2172 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
2173 ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
2174 bp->b_xflags |= xflags;
2175 if (xflags & BX_VNDIRTY)
2181 * Keep the list ordered. Optimize empty list insertion. Assume
2182 * we tend to grow at the tail so lookup_le should usually be cheaper
2185 if (bv->bv_cnt == 0 ||
2186 bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
2187 TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
2188 else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
2189 TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
2191 TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
2192 error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
2194 panic("buf_vlist_add: Preallocated nodes insufficient.");
2199 * Look up a buffer using the buffer tries.
2202 gbincore(struct bufobj *bo, daddr_t lblkno)
2206 ASSERT_BO_LOCKED(bo);
2207 bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
2210 return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
2214 * Associate a buffer with a vnode.
2217 bgetvp(struct vnode *vp, struct buf *bp)
2222 ASSERT_BO_WLOCKED(bo);
2223 VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
2225 CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
2226 VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
2227 ("bgetvp: bp already attached! %p", bp));
2233 * Insert onto list for new vnode.
2235 buf_vlist_add(bp, bo, BX_VNCLEAN);
2239 * Disassociate a buffer from a vnode.
2242 brelvp(struct buf *bp)
2247 CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
2248 KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
2251 * Delete from old vnode list, if on one.
2253 vp = bp->b_vp; /* XXX */
2256 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2257 buf_vlist_remove(bp);
2259 panic("brelvp: Buffer %p not on queue.", bp);
2260 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2261 bo->bo_flag &= ~BO_ONWORKLST;
2262 mtx_lock(&sync_mtx);
2263 LIST_REMOVE(bo, bo_synclist);
2264 syncer_worklist_len--;
2265 mtx_unlock(&sync_mtx);
2268 bp->b_bufobj = NULL;
2274 * Add an item to the syncer work queue.
2277 vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
2281 ASSERT_BO_WLOCKED(bo);
2283 mtx_lock(&sync_mtx);
2284 if (bo->bo_flag & BO_ONWORKLST)
2285 LIST_REMOVE(bo, bo_synclist);
2287 bo->bo_flag |= BO_ONWORKLST;
2288 syncer_worklist_len++;
2291 if (delay > syncer_maxdelay - 2)
2292 delay = syncer_maxdelay - 2;
2293 slot = (syncer_delayno + delay) & syncer_mask;
2295 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
2296 mtx_unlock(&sync_mtx);
2300 sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
2304 mtx_lock(&sync_mtx);
2305 len = syncer_worklist_len - sync_vnode_count;
2306 mtx_unlock(&sync_mtx);
2307 error = SYSCTL_OUT(req, &len, sizeof(len));
2311 SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
2312 sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
2314 static struct proc *updateproc;
2315 static void sched_sync(void);
2316 static struct kproc_desc up_kp = {
2321 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
2324 sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
2329 *bo = LIST_FIRST(slp);
2333 if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
2336 * We use vhold in case the vnode does not
2337 * successfully sync. vhold prevents the vnode from
2338 * going away when we unlock the sync_mtx so that
2339 * we can acquire the vnode interlock.
2342 mtx_unlock(&sync_mtx);
2344 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
2346 mtx_lock(&sync_mtx);
2347 return (*bo == LIST_FIRST(slp));
2349 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2350 (void) VOP_FSYNC(vp, MNT_LAZY, td);
2352 vn_finished_write(mp);
2354 if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
2356 * Put us back on the worklist. The worklist
2357 * routine will remove us from our current
2358 * position and then add us back in at a later
2361 vn_syncer_add_to_worklist(*bo, syncdelay);
2365 mtx_lock(&sync_mtx);
2369 static int first_printf = 1;
2372 * System filesystem synchronizer daemon.
2377 struct synclist *next, *slp;
2380 struct thread *td = curthread;
2382 int net_worklist_len;
2383 int syncer_final_iter;
2387 syncer_final_iter = 0;
2388 syncer_state = SYNCER_RUNNING;
2389 starttime = time_uptime;
2390 td->td_pflags |= TDP_NORUNNINGBUF;
2392 EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
2395 mtx_lock(&sync_mtx);
2397 if (syncer_state == SYNCER_FINAL_DELAY &&
2398 syncer_final_iter == 0) {
2399 mtx_unlock(&sync_mtx);
2400 kproc_suspend_check(td->td_proc);
2401 mtx_lock(&sync_mtx);
2403 net_worklist_len = syncer_worklist_len - sync_vnode_count;
2404 if (syncer_state != SYNCER_RUNNING &&
2405 starttime != time_uptime) {
2407 printf("\nSyncing disks, vnodes remaining... ");
2410 printf("%d ", net_worklist_len);
2412 starttime = time_uptime;
2415 * Push files whose dirty time has expired. Be careful
2416 * of interrupt race on slp queue.
2418 * Skip over empty worklist slots when shutting down.
2421 slp = &syncer_workitem_pending[syncer_delayno];
2422 syncer_delayno += 1;
2423 if (syncer_delayno == syncer_maxdelay)
2425 next = &syncer_workitem_pending[syncer_delayno];
2427 * If the worklist has wrapped since the
2428 * it was emptied of all but syncer vnodes,
2429 * switch to the FINAL_DELAY state and run
2430 * for one more second.
2432 if (syncer_state == SYNCER_SHUTTING_DOWN &&
2433 net_worklist_len == 0 &&
2434 last_work_seen == syncer_delayno) {
2435 syncer_state = SYNCER_FINAL_DELAY;
2436 syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
2438 } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
2439 syncer_worklist_len > 0);
2442 * Keep track of the last time there was anything
2443 * on the worklist other than syncer vnodes.
2444 * Return to the SHUTTING_DOWN state if any
2447 if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
2448 last_work_seen = syncer_delayno;
2449 if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
2450 syncer_state = SYNCER_SHUTTING_DOWN;
2451 while (!LIST_EMPTY(slp)) {
2452 error = sync_vnode(slp, &bo, td);
2454 LIST_REMOVE(bo, bo_synclist);
2455 LIST_INSERT_HEAD(next, bo, bo_synclist);
2459 if (first_printf == 0) {
2461 * Drop the sync mutex, because some watchdog
2462 * drivers need to sleep while patting
2464 mtx_unlock(&sync_mtx);
2465 wdog_kern_pat(WD_LASTVAL);
2466 mtx_lock(&sync_mtx);
2470 if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
2471 syncer_final_iter--;
2473 * The variable rushjob allows the kernel to speed up the
2474 * processing of the filesystem syncer process. A rushjob
2475 * value of N tells the filesystem syncer to process the next
2476 * N seconds worth of work on its queue ASAP. Currently rushjob
2477 * is used by the soft update code to speed up the filesystem
2478 * syncer process when the incore state is getting so far
2479 * ahead of the disk that the kernel memory pool is being
2480 * threatened with exhaustion.
2487 * Just sleep for a short period of time between
2488 * iterations when shutting down to allow some I/O
2491 * If it has taken us less than a second to process the
2492 * current work, then wait. Otherwise start right over
2493 * again. We can still lose time if any single round
2494 * takes more than two seconds, but it does not really
2495 * matter as we are just trying to generally pace the
2496 * filesystem activity.
2498 if (syncer_state != SYNCER_RUNNING ||
2499 time_uptime == starttime) {
2501 sched_prio(td, PPAUSE);
2504 if (syncer_state != SYNCER_RUNNING)
2505 cv_timedwait(&sync_wakeup, &sync_mtx,
2506 hz / SYNCER_SHUTDOWN_SPEEDUP);
2507 else if (time_uptime == starttime)
2508 cv_timedwait(&sync_wakeup, &sync_mtx, hz);
2513 * Request the syncer daemon to speed up its work.
2514 * We never push it to speed up more than half of its
2515 * normal turn time, otherwise it could take over the cpu.
2518 speedup_syncer(void)
2522 mtx_lock(&sync_mtx);
2523 if (rushjob < syncdelay / 2) {
2525 stat_rush_requests += 1;
2528 mtx_unlock(&sync_mtx);
2529 cv_broadcast(&sync_wakeup);
2534 * Tell the syncer to speed up its work and run though its work
2535 * list several times, then tell it to shut down.
2538 syncer_shutdown(void *arg, int howto)
2541 if (howto & RB_NOSYNC)
2543 mtx_lock(&sync_mtx);
2544 syncer_state = SYNCER_SHUTTING_DOWN;
2546 mtx_unlock(&sync_mtx);
2547 cv_broadcast(&sync_wakeup);
2548 kproc_shutdown(arg, howto);
2552 syncer_suspend(void)
2555 syncer_shutdown(updateproc, 0);
2562 mtx_lock(&sync_mtx);
2564 syncer_state = SYNCER_RUNNING;
2565 mtx_unlock(&sync_mtx);
2566 cv_broadcast(&sync_wakeup);
2567 kproc_resume(updateproc);
2571 * Reassign a buffer from one vnode to another.
2572 * Used to assign file specific control information
2573 * (indirect blocks) to the vnode to which they belong.
2576 reassignbuf(struct buf *bp)
2589 CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
2590 bp, bp->b_vp, bp->b_flags);
2592 * B_PAGING flagged buffers cannot be reassigned because their vp
2593 * is not fully linked in.
2595 if (bp->b_flags & B_PAGING)
2596 panic("cannot reassign paging buffer");
2599 * Delete from old vnode list, if on one.
2602 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
2603 buf_vlist_remove(bp);
2605 panic("reassignbuf: Buffer %p not on queue.", bp);
2607 * If dirty, put on list of dirty buffers; otherwise insert onto list
2610 if (bp->b_flags & B_DELWRI) {
2611 if ((bo->bo_flag & BO_ONWORKLST) == 0) {
2612 switch (vp->v_type) {
2622 vn_syncer_add_to_worklist(bo, delay);
2624 buf_vlist_add(bp, bo, BX_VNDIRTY);
2626 buf_vlist_add(bp, bo, BX_VNCLEAN);
2628 if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
2629 mtx_lock(&sync_mtx);
2630 LIST_REMOVE(bo, bo_synclist);
2631 syncer_worklist_len--;
2632 mtx_unlock(&sync_mtx);
2633 bo->bo_flag &= ~BO_ONWORKLST;
2638 bp = TAILQ_FIRST(&bv->bv_hd);
2639 KASSERT(bp == NULL || bp->b_bufobj == bo,
2640 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2641 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2642 KASSERT(bp == NULL || bp->b_bufobj == bo,
2643 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2645 bp = TAILQ_FIRST(&bv->bv_hd);
2646 KASSERT(bp == NULL || bp->b_bufobj == bo,
2647 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2648 bp = TAILQ_LAST(&bv->bv_hd, buflists);
2649 KASSERT(bp == NULL || bp->b_bufobj == bo,
2650 ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
2656 v_init_counters(struct vnode *vp)
2659 VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
2660 vp, ("%s called for an initialized vnode", __FUNCTION__));
2661 ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
2663 refcount_init(&vp->v_holdcnt, 1);
2664 refcount_init(&vp->v_usecount, 1);
2668 * Increment si_usecount of the associated device, if any.
2671 v_incr_devcount(struct vnode *vp)
2674 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2675 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2677 vp->v_rdev->si_usecount++;
2683 * Decrement si_usecount of the associated device, if any.
2686 v_decr_devcount(struct vnode *vp)
2689 ASSERT_VI_LOCKED(vp, __FUNCTION__);
2690 if (vp->v_type == VCHR && vp->v_rdev != NULL) {
2692 vp->v_rdev->si_usecount--;
2698 * Grab a particular vnode from the free list, increment its
2699 * reference count and lock it. VI_DOOMED is set if the vnode
2700 * is being destroyed. Only callers who specify LK_RETRY will
2701 * see doomed vnodes. If inactive processing was delayed in
2702 * vput try to do it here.
2704 * Both holdcnt and usecount can be manipulated using atomics without holding
2705 * any locks except in these cases which require the vnode interlock:
2706 * holdcnt: 1->0 and 0->1
2709 * usecount is permitted to transition 1->0 without the interlock because
2710 * vnode is kept live by holdcnt.
2712 static enum vgetstate
2713 _vget_prep(struct vnode *vp, bool interlock)
2717 if (__predict_true(vp->v_type != VCHR)) {
2718 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
2721 _vhold(vp, interlock);
2727 if (vp->v_usecount == 0) {
2731 v_incr_devcount(vp);
2732 refcount_acquire(&vp->v_usecount);
2742 vget_prep(struct vnode *vp)
2745 return (_vget_prep(vp, false));
2749 vget(struct vnode *vp, int flags, struct thread *td)
2753 MPASS(td == curthread);
2755 vs = _vget_prep(vp, (flags & LK_INTERLOCK) != 0);
2756 return (vget_finish(vp, flags, vs));
2760 vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
2762 int error, oweinact;
2764 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
2765 ("%s: invalid lock operation", __func__));
2767 if ((flags & LK_INTERLOCK) != 0)
2768 ASSERT_VI_LOCKED(vp, __func__);
2770 ASSERT_VI_UNLOCKED(vp, __func__);
2771 VNASSERT(vp->v_holdcnt > 0, vp, ("%s: vnode not held", __func__));
2772 if (vs == VGET_USECOUNT) {
2773 VNASSERT(vp->v_usecount > 0, vp,
2774 ("%s: vnode without usecount when VGET_USECOUNT was passed",
2778 if ((error = vn_lock(vp, flags)) != 0) {
2779 if (vs == VGET_USECOUNT)
2783 CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
2788 if (vs == VGET_USECOUNT) {
2789 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2790 ("%s: vnode with usecount and VI_OWEINACT set", __func__));
2795 * We hold the vnode. If the usecount is 0 it will be utilized to keep
2796 * the vnode around. Otherwise someone else lended their hold count and
2797 * we have to drop ours.
2799 if (vp->v_type != VCHR &&
2800 refcount_acquire_if_not_zero(&vp->v_usecount)) {
2802 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1) - 1;
2803 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
2805 refcount_release(&vp->v_holdcnt);
2807 VNODE_REFCOUNT_FENCE_ACQ();
2808 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2809 ("%s: vnode with usecount and VI_OWEINACT set", __func__));
2814 * We don't guarantee that any particular close will
2815 * trigger inactive processing so just make a best effort
2816 * here at preventing a reference to a removed file. If
2817 * we don't succeed no harm is done.
2819 * Upgrade our holdcnt to a usecount.
2823 * See the previous section. By the time we get here we may find
2824 * ourselves in the same spot.
2826 if (vp->v_type != VCHR) {
2827 if (refcount_acquire_if_not_zero(&vp->v_usecount)) {
2829 int old = atomic_fetchadd_int(&vp->v_holdcnt, -1) - 1;
2830 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
2832 refcount_release(&vp->v_holdcnt);
2834 VNODE_REFCOUNT_FENCE_ACQ();
2835 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2836 ("%s: vnode with usecount and VI_OWEINACT set",
2842 if (vp->v_usecount > 0)
2843 refcount_release(&vp->v_holdcnt);
2845 if ((vp->v_iflag & VI_OWEINACT) == 0) {
2849 vp->v_iflag &= ~VI_OWEINACT;
2850 VNODE_REFCOUNT_FENCE_REL();
2852 v_incr_devcount(vp);
2853 refcount_acquire(&vp->v_usecount);
2854 if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
2855 (flags & LK_NOWAIT) == 0)
2856 vinactive(vp, curthread);
2862 * Increase the reference (use) and hold count of a vnode.
2863 * This will also remove the vnode from the free list if it is presently free.
2866 vref(struct vnode *vp)
2869 ASSERT_VI_UNLOCKED(vp, __func__);
2870 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2871 if (vp->v_type != VCHR &&
2872 refcount_acquire_if_not_zero(&vp->v_usecount)) {
2873 VNODE_REFCOUNT_FENCE_ACQ();
2874 VNASSERT(vp->v_holdcnt > 0, vp,
2875 ("%s: active vnode not held", __func__));
2876 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2877 ("%s: vnode with usecount and VI_OWEINACT set", __func__));
2886 vrefl(struct vnode *vp)
2889 ASSERT_VI_LOCKED(vp, __func__);
2890 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2891 if (vp->v_type != VCHR &&
2892 refcount_acquire_if_not_zero(&vp->v_usecount)) {
2893 VNODE_REFCOUNT_FENCE_ACQ();
2894 VNASSERT(vp->v_holdcnt > 0, vp,
2895 ("%s: active vnode not held", __func__));
2896 VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
2897 ("%s: vnode with usecount and VI_OWEINACT set", __func__));
2900 if (vp->v_usecount == 0)
2902 if ((vp->v_iflag & VI_OWEINACT) != 0) {
2903 vp->v_iflag &= ~VI_OWEINACT;
2904 VNODE_REFCOUNT_FENCE_REL();
2906 v_incr_devcount(vp);
2907 refcount_acquire(&vp->v_usecount);
2911 vrefact(struct vnode *vp)
2914 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2915 if (__predict_false(vp->v_type == VCHR)) {
2916 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp,
2917 ("%s: wrong ref counts", __func__));
2922 int old = atomic_fetchadd_int(&vp->v_usecount, 1);
2923 VNASSERT(old > 0, vp, ("%s: wrong use count", __func__));
2925 refcount_acquire(&vp->v_usecount);
2930 * Return reference count of a vnode.
2932 * The results of this call are only guaranteed when some mechanism is used to
2933 * stop other processes from gaining references to the vnode. This may be the
2934 * case if the caller holds the only reference. This is also useful when stale
2935 * data is acceptable as race conditions may be accounted for by some other
2939 vrefcnt(struct vnode *vp)
2942 return (vp->v_usecount);
2945 #define VPUTX_VRELE 1
2946 #define VPUTX_VPUT 2
2947 #define VPUTX_VUNREF 3
2950 * Decrement the use and hold counts for a vnode.
2952 * See an explanation near vget() as to why atomic operation is safe.
2955 vputx(struct vnode *vp, int func)
2959 KASSERT(vp != NULL, ("vputx: null vp"));
2960 if (func == VPUTX_VUNREF)
2961 ASSERT_VOP_LOCKED(vp, "vunref");
2962 else if (func == VPUTX_VPUT)
2963 ASSERT_VOP_LOCKED(vp, "vput");
2965 KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
2966 ASSERT_VI_UNLOCKED(vp, __func__);
2967 VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp,
2968 ("%s: wrong ref counts", __func__));
2970 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
2973 * It is an invariant that all VOP_* calls operate on a held vnode.
2974 * We may be only having an implicit hold stemming from our usecount,
2975 * which we are about to release. If we unlock the vnode afterwards we
2976 * open a time window where someone else dropped the last usecount and
2977 * proceeded to free the vnode before our unlock finished. For this
2978 * reason we unlock the vnode early. This is a little bit wasteful as
2979 * it may be the vnode is exclusively locked and inactive processing is
2980 * needed, in which case we are adding work.
2982 if (func == VPUTX_VPUT)
2986 * We want to hold the vnode until the inactive finishes to
2987 * prevent vgone() races. We drop the use count here and the
2988 * hold count below when we're done.
2990 if (vp->v_type != VCHR) {
2992 * If we release the last usecount we take ownership of the hold
2993 * count which provides liveness of the vnode, in which case we
2996 if (!refcount_release(&vp->v_usecount))
3000 * By the time we got here someone else might have transitioned
3001 * the count back to > 0.
3003 if (vp->v_usecount > 0) {
3009 v_decr_devcount(vp);
3010 if (!refcount_release(&vp->v_usecount)) {
3015 if (vp->v_iflag & VI_DOINGINACT) {
3022 if (vp->v_usecount != 0) {
3023 vn_printf(vp, "vputx: usecount not zero for vnode ");
3024 panic("vputx: usecount not zero");
3027 CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
3030 * Check if the fs wants to perform inactive processing. Note we
3031 * may be only holding the interlock, in which case it is possible
3032 * someone else called vgone on the vnode and ->v_data is now NULL.
3033 * Since vgone performs inactive on its own there is nothing to do
3034 * here but to drop our hold count.
3036 if (__predict_false(vp->v_iflag & VI_DOOMED) ||
3037 VOP_NEED_INACTIVE(vp) == 0) {
3043 * We must call VOP_INACTIVE with the node locked. Mark
3044 * as VI_DOINGINACT to avoid recursion.
3046 vp->v_iflag |= VI_OWEINACT;
3049 error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
3053 error = VOP_LOCK(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_NOWAIT);
3057 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
3058 error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
3063 VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp,
3064 ("vnode with usecount and VI_OWEINACT set"));
3066 if (vp->v_iflag & VI_OWEINACT)
3067 vinactive(vp, curthread);
3068 if (func != VPUTX_VUNREF)
3075 * Vnode put/release.
3076 * If count drops to zero, call inactive routine and return to freelist.
3079 vrele(struct vnode *vp)
3082 vputx(vp, VPUTX_VRELE);
3086 * Release an already locked vnode. This give the same effects as
3087 * unlock+vrele(), but takes less time and avoids releasing and
3088 * re-aquiring the lock (as vrele() acquires the lock internally.)
3091 vput(struct vnode *vp)
3094 vputx(vp, VPUTX_VPUT);
3098 * Release an exclusively locked vnode. Do not unlock the vnode lock.
3101 vunref(struct vnode *vp)
3104 vputx(vp, VPUTX_VUNREF);
3108 * Increase the hold count and activate if this is the first reference.
3111 _vhold(struct vnode *vp, bool locked)
3116 ASSERT_VI_LOCKED(vp, __func__);
3118 ASSERT_VI_UNLOCKED(vp, __func__);
3119 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3121 if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) {
3122 VNODE_REFCOUNT_FENCE_ACQ();
3123 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
3124 ("_vhold: vnode with holdcnt is free"));
3129 if ((vp->v_iflag & VI_FREE) == 0) {
3130 refcount_acquire(&vp->v_holdcnt);
3135 VNASSERT(vp->v_holdcnt == 0, vp,
3136 ("%s: wrong hold count", __func__));
3137 VNASSERT(vp->v_op != NULL, vp,
3138 ("%s: vnode already reclaimed.", __func__));
3140 * Remove a vnode from the free list, mark it as in use,
3141 * and put it on the active list.
3143 VNASSERT(vp->v_mount != NULL, vp,
3144 ("_vhold: vnode not on per mount vnode list"));
3146 mtx_lock(&mp->mnt_listmtx);
3147 if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) {
3148 TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist);
3149 mp->mnt_tmpfreevnodelistsize--;
3150 vp->v_mflag &= ~VMP_TMPMNTFREELIST;
3152 mtx_lock(&vnode_free_list_mtx);
3153 TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
3155 mtx_unlock(&vnode_free_list_mtx);
3157 KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
3158 ("Activating already active vnode"));
3159 vp->v_iflag &= ~VI_FREE;
3160 vp->v_iflag |= VI_ACTIVE;
3161 TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
3162 mp->mnt_activevnodelistsize++;
3163 mtx_unlock(&mp->mnt_listmtx);
3164 refcount_acquire(&vp->v_holdcnt);
3170 vholdnz(struct vnode *vp)
3173 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3175 int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
3176 VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
3178 atomic_add_int(&vp->v_holdcnt, 1);
3183 * Drop the hold count of the vnode. If this is the last reference to
3184 * the vnode we place it on the free list unless it has been vgone'd
3185 * (marked VI_DOOMED) in which case we will free it.
3187 * Because the vnode vm object keeps a hold reference on the vnode if
3188 * there is at least one resident non-cached page, the vnode cannot
3189 * leave the active list without the page cleanup done.
3192 _vdrop(struct vnode *vp, bool locked)
3199 ASSERT_VI_LOCKED(vp, __func__);
3201 ASSERT_VI_UNLOCKED(vp, __func__);
3202 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3203 if (__predict_false((int)vp->v_holdcnt <= 0)) {
3204 vn_printf(vp, "vdrop: holdcnt %d", vp->v_holdcnt);
3205 panic("vdrop: wrong holdcnt");
3208 if (refcount_release_if_not_last(&vp->v_holdcnt))
3212 if (refcount_release(&vp->v_holdcnt) == 0) {
3216 if ((vp->v_iflag & VI_DOOMED) == 0) {
3218 * Mark a vnode as free: remove it from its active list
3219 * and put it up for recycling on the freelist.
3221 VNASSERT(vp->v_op != NULL, vp,
3222 ("vdropl: vnode already reclaimed."));
3223 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
3224 ("vnode already free"));
3225 VNASSERT(vp->v_holdcnt == 0, vp,
3226 ("vdropl: freeing when we shouldn't"));
3227 active = vp->v_iflag & VI_ACTIVE;
3228 if ((vp->v_iflag & VI_OWEINACT) == 0) {
3229 vp->v_iflag &= ~VI_ACTIVE;
3232 mtx_lock(&mp->mnt_listmtx);
3234 TAILQ_REMOVE(&mp->mnt_activevnodelist,
3236 mp->mnt_activevnodelistsize--;
3238 TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist,
3240 mp->mnt_tmpfreevnodelistsize++;
3241 vp->v_iflag |= VI_FREE;
3242 vp->v_mflag |= VMP_TMPMNTFREELIST;
3244 if (mp->mnt_tmpfreevnodelistsize >=
3245 mnt_free_list_batch)
3246 vnlru_return_batch_locked(mp);
3247 mtx_unlock(&mp->mnt_listmtx);
3249 VNASSERT(active == 0, vp,
3250 ("vdropl: active vnode not on per mount "
3252 mtx_lock(&vnode_free_list_mtx);
3253 TAILQ_INSERT_TAIL(&vnode_free_list, vp,
3256 vp->v_iflag |= VI_FREE;
3258 mtx_unlock(&vnode_free_list_mtx);
3262 counter_u64_add(free_owe_inact, 1);
3267 * The vnode has been marked for destruction, so free it.
3269 * The vnode will be returned to the zone where it will
3270 * normally remain until it is needed for another vnode. We
3271 * need to cleanup (or verify that the cleanup has already
3272 * been done) any residual data left from its current use
3273 * so as not to contaminate the freshly allocated vnode.
3275 CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
3276 atomic_subtract_long(&numvnodes, 1);
3278 VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
3279 ("cleaned vnode still on the free list."));
3280 VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
3281 VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
3282 VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
3283 VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
3284 VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
3285 VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
3286 VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
3287 ("clean blk trie not empty"));
3288 VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
3289 VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
3290 ("dirty blk trie not empty"));
3291 VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
3292 VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
3293 VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
3294 VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp,
3295 ("Dangling rangelock waiters"));
3298 mac_vnode_destroy(vp);
3300 if (vp->v_pollinfo != NULL) {
3301 destroy_vpollinfo(vp->v_pollinfo);
3302 vp->v_pollinfo = NULL;
3305 /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
3308 vp->v_mountedhere = NULL;
3311 vp->v_fifoinfo = NULL;
3312 vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
3316 uma_zfree(vnode_zone, vp);
3320 * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
3321 * flags. DOINGINACT prevents us from recursing in calls to vinactive.
3322 * OWEINACT tracks whether a vnode missed a call to inactive due to a
3323 * failed lock upgrade.
3326 vinactive(struct vnode *vp, struct thread *td)
3328 struct vm_object *obj;
3330 ASSERT_VOP_ELOCKED(vp, "vinactive");
3331 ASSERT_VI_LOCKED(vp, "vinactive");
3332 VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
3333 ("vinactive: recursed on VI_DOINGINACT"));
3334 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3335 vp->v_iflag |= VI_DOINGINACT;
3336 vp->v_iflag &= ~VI_OWEINACT;
3339 * Before moving off the active list, we must be sure that any
3340 * modified pages are converted into the vnode's dirty
3341 * buffers, since these will no longer be checked once the
3342 * vnode is on the inactive list.
3344 * The write-out of the dirty pages is asynchronous. At the
3345 * point that VOP_INACTIVE() is called, there could still be
3346 * pending I/O and dirty pages in the object.
3348 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
3349 vm_object_mightbedirty(obj)) {
3350 VM_OBJECT_WLOCK(obj);
3351 vm_object_page_clean(obj, 0, 0, 0);
3352 VM_OBJECT_WUNLOCK(obj);
3354 VOP_INACTIVE(vp, td);
3356 VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
3357 ("vinactive: lost VI_DOINGINACT"));
3358 vp->v_iflag &= ~VI_DOINGINACT;
3362 * Remove any vnodes in the vnode table belonging to mount point mp.
3364 * If FORCECLOSE is not specified, there should not be any active ones,
3365 * return error if any are found (nb: this is a user error, not a
3366 * system error). If FORCECLOSE is specified, detach any active vnodes
3369 * If WRITECLOSE is set, only flush out regular file vnodes open for
3372 * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
3374 * `rootrefs' specifies the base reference count for the root vnode
3375 * of this filesystem. The root vnode is considered busy if its
3376 * v_usecount exceeds this value. On a successful return, vflush(, td)
3377 * will call vrele() on the root vnode exactly rootrefs times.
3378 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
3382 static int busyprt = 0; /* print out busy vnodes */
3383 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
3387 vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
3389 struct vnode *vp, *mvp, *rootvp = NULL;
3391 int busy = 0, error;
3393 CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
3396 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
3397 ("vflush: bad args"));
3399 * Get the filesystem root vnode. We can vput() it
3400 * immediately, since with rootrefs > 0, it won't go away.
3402 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
3403 CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
3410 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
3412 error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
3415 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
3419 * Skip over a vnodes marked VV_SYSTEM.
3421 if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
3427 * If WRITECLOSE is set, flush out unlinked but still open
3428 * files (even if open only for reading) and regular file
3429 * vnodes open for writing.
3431 if (flags & WRITECLOSE) {
3432 if (vp->v_object != NULL) {
3433 VM_OBJECT_WLOCK(vp->v_object);
3434 vm_object_page_clean(vp->v_object, 0, 0, 0);
3435 VM_OBJECT_WUNLOCK(vp->v_object);
3437 error = VOP_FSYNC(vp, MNT_WAIT, td);
3441 MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
3444 error = VOP_GETATTR(vp, &vattr, td->td_ucred);
3447 if ((vp->v_type == VNON ||
3448 (error == 0 && vattr.va_nlink > 0)) &&
3449 (vp->v_writecount <= 0 || vp->v_type != VREG)) {
3457 * With v_usecount == 0, all we need to do is clear out the
3458 * vnode data structures and we are done.
3460 * If FORCECLOSE is set, forcibly close the vnode.
3462 if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
3468 vn_printf(vp, "vflush: busy vnode ");
3474 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
3476 * If just the root vnode is busy, and if its refcount
3477 * is equal to `rootrefs', then go ahead and kill it.
3480 KASSERT(busy > 0, ("vflush: not busy"));
3481 VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
3482 ("vflush: usecount %d < rootrefs %d",
3483 rootvp->v_usecount, rootrefs));
3484 if (busy == 1 && rootvp->v_usecount == rootrefs) {
3485 VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
3487 VOP_UNLOCK(rootvp, 0);
3493 CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
3497 for (; rootrefs > 0; rootrefs--)
3503 * Recycle an unused vnode to the front of the free list.
3506 vrecycle(struct vnode *vp)
3511 recycled = vrecyclel(vp);
3517 * vrecycle, with the vp interlock held.
3520 vrecyclel(struct vnode *vp)
3524 ASSERT_VOP_ELOCKED(vp, __func__);
3525 ASSERT_VI_LOCKED(vp, __func__);
3526 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3528 if (vp->v_usecount == 0) {
3536 * Eliminate all activity associated with a vnode
3537 * in preparation for reuse.
3540 vgone(struct vnode *vp)
3548 notify_lowervp_vfs_dummy(struct mount *mp __unused,
3549 struct vnode *lowervp __unused)
3554 * Notify upper mounts about reclaimed or unlinked vnode.
3557 vfs_notify_upper(struct vnode *vp, int event)
3559 static struct vfsops vgonel_vfsops = {
3560 .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy,
3561 .vfs_unlink_lowervp = notify_lowervp_vfs_dummy,
3563 struct mount *mp, *ump, *mmp;
3570 if (TAILQ_EMPTY(&mp->mnt_uppers))
3573 mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO);
3574 mmp->mnt_op = &vgonel_vfsops;
3575 mmp->mnt_kern_flag |= MNTK_MARKER;
3577 mp->mnt_kern_flag |= MNTK_VGONE_UPPER;
3578 for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) {
3579 if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) {
3580 ump = TAILQ_NEXT(ump, mnt_upper_link);
3583 TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link);
3586 case VFS_NOTIFY_UPPER_RECLAIM:
3587 VFS_RECLAIM_LOWERVP(ump, vp);
3589 case VFS_NOTIFY_UPPER_UNLINK:
3590 VFS_UNLINK_LOWERVP(ump, vp);
3593 KASSERT(0, ("invalid event %d", event));
3597 ump = TAILQ_NEXT(mmp, mnt_upper_link);
3598 TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link);
3601 mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER;
3602 if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) {
3603 mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER;
3604 wakeup(&mp->mnt_uppers);
3611 * vgone, with the vp interlock held.
3614 vgonel(struct vnode *vp)
3619 bool active, oweinact;
3621 ASSERT_VOP_ELOCKED(vp, "vgonel");
3622 ASSERT_VI_LOCKED(vp, "vgonel");
3623 VNASSERT(vp->v_holdcnt, vp,
3624 ("vgonel: vp %p has no reference.", vp));
3625 CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
3629 * Don't vgonel if we're already doomed.
3631 if (vp->v_iflag & VI_DOOMED)
3633 vp->v_iflag |= VI_DOOMED;
3636 * Check to see if the vnode is in use. If so, we have to call
3637 * VOP_CLOSE() and VOP_INACTIVE().
3639 active = vp->v_usecount > 0;
3640 oweinact = (vp->v_iflag & VI_OWEINACT) != 0;
3642 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
3645 * If purging an active vnode, it must be closed and
3646 * deactivated before being reclaimed.
3649 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
3650 if (oweinact || active) {
3652 if ((vp->v_iflag & VI_DOINGINACT) == 0)
3656 if (vp->v_type == VSOCK)
3657 vfs_unp_reclaim(vp);
3660 * Clean out any buffers associated with the vnode.
3661 * If the flush fails, just toss the buffers.
3664 if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
3665 (void) vn_start_secondary_write(vp, &mp, V_WAIT);
3666 if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
3667 while (vinvalbuf(vp, 0, 0, 0) != 0)
3671 BO_LOCK(&vp->v_bufobj);
3672 KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
3673 vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
3674 TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
3675 vp->v_bufobj.bo_clean.bv_cnt == 0,
3676 ("vp %p bufobj not invalidated", vp));
3679 * For VMIO bufobj, BO_DEAD is set later, or in
3680 * vm_object_terminate() after the object's page queue is
3683 object = vp->v_bufobj.bo_object;
3685 vp->v_bufobj.bo_flag |= BO_DEAD;
3686 BO_UNLOCK(&vp->v_bufobj);
3689 * Handle the VM part. Tmpfs handles v_object on its own (the
3690 * OBJT_VNODE check). Nullfs or other bypassing filesystems
3691 * should not touch the object borrowed from the lower vnode
3692 * (the handle check).
3694 if (object != NULL && object->type == OBJT_VNODE &&
3695 object->handle == vp)
3696 vnode_destroy_vobject(vp);
3699 * Reclaim the vnode.
3701 if (VOP_RECLAIM(vp, td))
3702 panic("vgone: cannot reclaim");
3704 vn_finished_secondary_write(mp);
3705 VNASSERT(vp->v_object == NULL, vp,
3706 ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
3708 * Clear the advisory locks and wake up waiting threads.
3710 (void)VOP_ADVLOCKPURGE(vp);
3713 * Delete from old mount point vnode list.
3718 * Done with purge, reset to the standard lock and invalidate
3722 vp->v_vnlock = &vp->v_lock;
3723 vp->v_op = &dead_vnodeops;
3729 * Calculate the total number of references to a special device.
3732 vcount(struct vnode *vp)
3737 count = vp->v_rdev->si_usecount;
3743 * Same as above, but using the struct cdev *as argument
3746 count_dev(struct cdev *dev)
3751 count = dev->si_usecount;
3757 * Print out a description of a vnode.
3759 static char *typename[] =
3760 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
3764 vn_printf(struct vnode *vp, const char *fmt, ...)
3767 char buf[256], buf2[16];
3773 printf("%p: ", (void *)vp);
3774 printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
3775 printf(" usecount %d, writecount %d, refcount %d",
3776 vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
3777 switch (vp->v_type) {
3779 printf(" mountedhere %p\n", vp->v_mountedhere);
3782 printf(" rdev %p\n", vp->v_rdev);
3785 printf(" socket %p\n", vp->v_unpcb);
3788 printf(" fifoinfo %p\n", vp->v_fifoinfo);
3796 if (vp->v_vflag & VV_ROOT)
3797 strlcat(buf, "|VV_ROOT", sizeof(buf));
3798 if (vp->v_vflag & VV_ISTTY)
3799 strlcat(buf, "|VV_ISTTY", sizeof(buf));
3800 if (vp->v_vflag & VV_NOSYNC)
3801 strlcat(buf, "|VV_NOSYNC", sizeof(buf));
3802 if (vp->v_vflag & VV_ETERNALDEV)
3803 strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
3804 if (vp->v_vflag & VV_CACHEDLABEL)
3805 strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
3806 if (vp->v_vflag & VV_COPYONWRITE)
3807 strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
3808 if (vp->v_vflag & VV_SYSTEM)
3809 strlcat(buf, "|VV_SYSTEM", sizeof(buf));
3810 if (vp->v_vflag & VV_PROCDEP)
3811 strlcat(buf, "|VV_PROCDEP", sizeof(buf));
3812 if (vp->v_vflag & VV_NOKNOTE)
3813 strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
3814 if (vp->v_vflag & VV_DELETED)
3815 strlcat(buf, "|VV_DELETED", sizeof(buf));
3816 if (vp->v_vflag & VV_MD)
3817 strlcat(buf, "|VV_MD", sizeof(buf));
3818 if (vp->v_vflag & VV_FORCEINSMQ)
3819 strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
3820 flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
3821 VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
3822 VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ);
3824 snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
3825 strlcat(buf, buf2, sizeof(buf));
3827 if (vp->v_iflag & VI_MOUNT)
3828 strlcat(buf, "|VI_MOUNT", sizeof(buf));
3829 if (vp->v_iflag & VI_DOOMED)
3830 strlcat(buf, "|VI_DOOMED", sizeof(buf));
3831 if (vp->v_iflag & VI_FREE)
3832 strlcat(buf, "|VI_FREE", sizeof(buf));
3833 if (vp->v_iflag & VI_ACTIVE)
3834 strlcat(buf, "|VI_ACTIVE", sizeof(buf));
3835 if (vp->v_iflag & VI_DOINGINACT)
3836 strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
3837 if (vp->v_iflag & VI_OWEINACT)
3838 strlcat(buf, "|VI_OWEINACT", sizeof(buf));
3839 if (vp->v_iflag & VI_TEXT_REF)
3840 strlcat(buf, "|VI_TEXT_REF", sizeof(buf));
3841 flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE |
3842 VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT | VI_TEXT_REF);
3844 snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
3845 strlcat(buf, buf2, sizeof(buf));
3847 printf(" flags (%s)\n", buf + 1);
3848 if (mtx_owned(VI_MTX(vp)))
3849 printf(" VI_LOCKed");
3850 if (vp->v_object != NULL)
3851 printf(" v_object %p ref %d pages %d "
3852 "cleanbuf %d dirtybuf %d\n",
3853 vp->v_object, vp->v_object->ref_count,
3854 vp->v_object->resident_page_count,
3855 vp->v_bufobj.bo_clean.bv_cnt,
3856 vp->v_bufobj.bo_dirty.bv_cnt);
3858 lockmgr_printinfo(vp->v_vnlock);
3859 if (vp->v_data != NULL)
3865 * List all of the locked vnodes in the system.
3866 * Called when debugging the kernel.
3868 DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
3874 * Note: because this is DDB, we can't obey the locking semantics
3875 * for these structures, which means we could catch an inconsistent
3876 * state and dereference a nasty pointer. Not much to be done
3879 db_printf("Locked vnodes\n");
3880 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3881 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
3882 if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
3883 vn_printf(vp, "vnode ");
3889 * Show details about the given vnode.
3891 DB_SHOW_COMMAND(vnode, db_show_vnode)
3897 vp = (struct vnode *)addr;
3898 vn_printf(vp, "vnode ");
3902 * Show details about the given mount point.
3904 DB_SHOW_COMMAND(mount, db_show_mount)
3915 /* No address given, print short info about all mount points. */
3916 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
3917 db_printf("%p %s on %s (%s)\n", mp,
3918 mp->mnt_stat.f_mntfromname,
3919 mp->mnt_stat.f_mntonname,
3920 mp->mnt_stat.f_fstypename);
3924 db_printf("\nMore info: show mount <addr>\n");
3928 mp = (struct mount *)addr;
3929 db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
3930 mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
3933 mflags = mp->mnt_flag;
3934 #define MNT_FLAG(flag) do { \
3935 if (mflags & (flag)) { \
3936 if (buf[0] != '\0') \
3937 strlcat(buf, ", ", sizeof(buf)); \
3938 strlcat(buf, (#flag) + 4, sizeof(buf)); \
3939 mflags &= ~(flag); \
3942 MNT_FLAG(MNT_RDONLY);
3943 MNT_FLAG(MNT_SYNCHRONOUS);
3944 MNT_FLAG(MNT_NOEXEC);
3945 MNT_FLAG(MNT_NOSUID);
3946 MNT_FLAG(MNT_NFS4ACLS);
3947 MNT_FLAG(MNT_UNION);
3948 MNT_FLAG(MNT_ASYNC);
3949 MNT_FLAG(MNT_SUIDDIR);
3950 MNT_FLAG(MNT_SOFTDEP);
3951 MNT_FLAG(MNT_NOSYMFOLLOW);
3952 MNT_FLAG(MNT_GJOURNAL);
3953 MNT_FLAG(MNT_MULTILABEL);
3955 MNT_FLAG(MNT_NOATIME);
3956 MNT_FLAG(MNT_NOCLUSTERR);
3957 MNT_FLAG(MNT_NOCLUSTERW);
3959 MNT_FLAG(MNT_EXRDONLY);
3960 MNT_FLAG(MNT_EXPORTED);
3961 MNT_FLAG(MNT_DEFEXPORTED);
3962 MNT_FLAG(MNT_EXPORTANON);
3963 MNT_FLAG(MNT_EXKERB);
3964 MNT_FLAG(MNT_EXPUBLIC);
3965 MNT_FLAG(MNT_LOCAL);
3966 MNT_FLAG(MNT_QUOTA);
3967 MNT_FLAG(MNT_ROOTFS);
3969 MNT_FLAG(MNT_IGNORE);
3970 MNT_FLAG(MNT_UPDATE);
3971 MNT_FLAG(MNT_DELEXPORT);
3972 MNT_FLAG(MNT_RELOAD);
3973 MNT_FLAG(MNT_FORCE);
3974 MNT_FLAG(MNT_SNAPSHOT);
3975 MNT_FLAG(MNT_BYFSID);
3979 strlcat(buf, ", ", sizeof(buf));
3980 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
3981 "0x%016jx", mflags);
3983 db_printf(" mnt_flag = %s\n", buf);
3986 flags = mp->mnt_kern_flag;
3987 #define MNT_KERN_FLAG(flag) do { \
3988 if (flags & (flag)) { \
3989 if (buf[0] != '\0') \
3990 strlcat(buf, ", ", sizeof(buf)); \
3991 strlcat(buf, (#flag) + 5, sizeof(buf)); \
3995 MNT_KERN_FLAG(MNTK_UNMOUNTF);
3996 MNT_KERN_FLAG(MNTK_ASYNC);
3997 MNT_KERN_FLAG(MNTK_SOFTDEP);
3998 MNT_KERN_FLAG(MNTK_DRAINING);
3999 MNT_KERN_FLAG(MNTK_REFEXPIRE);
4000 MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
4001 MNT_KERN_FLAG(MNTK_SHARED_WRITES);
4002 MNT_KERN_FLAG(MNTK_NO_IOPF);
4003 MNT_KERN_FLAG(MNTK_VGONE_UPPER);
4004 MNT_KERN_FLAG(MNTK_VGONE_WAITER);
4005 MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT);
4006 MNT_KERN_FLAG(MNTK_MARKER);
4007 MNT_KERN_FLAG(MNTK_USES_BCACHE);
4008 MNT_KERN_FLAG(MNTK_NOASYNC);
4009 MNT_KERN_FLAG(MNTK_UNMOUNT);
4010 MNT_KERN_FLAG(MNTK_MWAIT);
4011 MNT_KERN_FLAG(MNTK_SUSPEND);
4012 MNT_KERN_FLAG(MNTK_SUSPEND2);
4013 MNT_KERN_FLAG(MNTK_SUSPENDED);
4014 MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
4015 MNT_KERN_FLAG(MNTK_NOKNOTE);
4016 #undef MNT_KERN_FLAG
4019 strlcat(buf, ", ", sizeof(buf));
4020 snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
4023 db_printf(" mnt_kern_flag = %s\n", buf);
4025 db_printf(" mnt_opt = ");
4026 opt = TAILQ_FIRST(mp->mnt_opt);
4028 db_printf("%s", opt->name);
4029 opt = TAILQ_NEXT(opt, link);
4030 while (opt != NULL) {
4031 db_printf(", %s", opt->name);
4032 opt = TAILQ_NEXT(opt, link);
4038 db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
4039 "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
4040 "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
4041 "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
4042 (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
4043 (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
4044 (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
4045 (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
4046 (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
4047 (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
4048 (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
4049 (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
4051 db_printf(" mnt_cred = { uid=%u ruid=%u",
4052 (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
4053 if (jailed(mp->mnt_cred))
4054 db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
4056 db_printf(" mnt_ref = %d (with %d in the struct)\n",
4057 vfs_mount_fetch_counter(mp, MNT_COUNT_REF), mp->mnt_ref);
4058 db_printf(" mnt_gen = %d\n", mp->mnt_gen);
4059 db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
4060 db_printf(" mnt_activevnodelistsize = %d\n",
4061 mp->mnt_activevnodelistsize);
4062 db_printf(" mnt_writeopcount = %d (with %d in the struct)\n",
4063 vfs_mount_fetch_counter(mp, MNT_COUNT_WRITEOPCOUNT), mp->mnt_writeopcount);
4064 db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
4065 db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
4066 db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
4067 db_printf(" mnt_lockref = %d (with %d in the struct)\n",
4068 vfs_mount_fetch_counter(mp, MNT_COUNT_LOCKREF), mp->mnt_lockref);
4069 db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
4070 db_printf(" mnt_secondary_accwrites = %d\n",
4071 mp->mnt_secondary_accwrites);
4072 db_printf(" mnt_gjprovider = %s\n",
4073 mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
4074 db_printf(" mnt_vfs_ops = %d\n", mp->mnt_vfs_ops);
4076 db_printf("\n\nList of active vnodes\n");
4077 TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
4078 if (vp->v_type != VMARKER) {
4079 vn_printf(vp, "vnode ");
4084 db_printf("\n\nList of inactive vnodes\n");
4085 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4086 if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
4087 vn_printf(vp, "vnode ");
4096 * Fill in a struct xvfsconf based on a struct vfsconf.
4099 vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
4101 struct xvfsconf xvfsp;
4103 bzero(&xvfsp, sizeof(xvfsp));
4104 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4105 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4106 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4107 xvfsp.vfc_flags = vfsp->vfc_flags;
4109 * These are unused in userland, we keep them
4110 * to not break binary compatibility.
4112 xvfsp.vfc_vfsops = NULL;
4113 xvfsp.vfc_next = NULL;
4114 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4117 #ifdef COMPAT_FREEBSD32
4119 uint32_t vfc_vfsops;
4120 char vfc_name[MFSNAMELEN];
4121 int32_t vfc_typenum;
4122 int32_t vfc_refcount;
4128 vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
4130 struct xvfsconf32 xvfsp;
4132 bzero(&xvfsp, sizeof(xvfsp));
4133 strcpy(xvfsp.vfc_name, vfsp->vfc_name);
4134 xvfsp.vfc_typenum = vfsp->vfc_typenum;
4135 xvfsp.vfc_refcount = vfsp->vfc_refcount;
4136 xvfsp.vfc_flags = vfsp->vfc_flags;
4137 return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
4142 * Top level filesystem related information gathering.
4145 sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
4147 struct vfsconf *vfsp;
4152 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4153 #ifdef COMPAT_FREEBSD32
4154 if (req->flags & SCTL_MASK32)
4155 error = vfsconf2x32(req, vfsp);
4158 error = vfsconf2x(req, vfsp);
4166 SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
4167 CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
4168 "S,xvfsconf", "List of all configured filesystems");
4170 #ifndef BURN_BRIDGES
4171 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
4174 vfs_sysctl(SYSCTL_HANDLER_ARGS)
4176 int *name = (int *)arg1 - 1; /* XXX */
4177 u_int namelen = arg2 + 1; /* XXX */
4178 struct vfsconf *vfsp;
4180 log(LOG_WARNING, "userland calling deprecated sysctl, "
4181 "please rebuild world\n");
4183 #if 1 || defined(COMPAT_PRELITE2)
4184 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
4186 return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
4190 case VFS_MAXTYPENUM:
4193 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
4196 return (ENOTDIR); /* overloaded */
4198 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4199 if (vfsp->vfc_typenum == name[2])
4204 return (EOPNOTSUPP);
4205 #ifdef COMPAT_FREEBSD32
4206 if (req->flags & SCTL_MASK32)
4207 return (vfsconf2x32(req, vfsp));
4210 return (vfsconf2x(req, vfsp));
4212 return (EOPNOTSUPP);
4215 static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
4216 CTLFLAG_MPSAFE, vfs_sysctl,
4217 "Generic filesystem");
4219 #if 1 || defined(COMPAT_PRELITE2)
4222 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
4225 struct vfsconf *vfsp;
4226 struct ovfsconf ovfs;
4229 TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
4230 bzero(&ovfs, sizeof(ovfs));
4231 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
4232 strcpy(ovfs.vfc_name, vfsp->vfc_name);
4233 ovfs.vfc_index = vfsp->vfc_typenum;
4234 ovfs.vfc_refcount = vfsp->vfc_refcount;
4235 ovfs.vfc_flags = vfsp->vfc_flags;
4236 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
4246 #endif /* 1 || COMPAT_PRELITE2 */
4247 #endif /* !BURN_BRIDGES */
4249 #define KINFO_VNODESLOP 10
4252 * Dump vnode list (via sysctl).
4256 sysctl_vnode(SYSCTL_HANDLER_ARGS)
4264 * Stale numvnodes access is not fatal here.
4267 len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
4269 /* Make an estimate */
4270 return (SYSCTL_OUT(req, 0, len));
4272 error = sysctl_wire_old_buffer(req, 0);
4275 xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
4277 mtx_lock(&mountlist_mtx);
4278 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
4279 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
4282 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
4286 xvn[n].xv_size = sizeof *xvn;
4287 xvn[n].xv_vnode = vp;
4288 xvn[n].xv_id = 0; /* XXX compat */
4289 #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
4291 XV_COPY(writecount);
4297 xvn[n].xv_flag = vp->v_vflag;
4299 switch (vp->v_type) {
4306 if (vp->v_rdev == NULL) {
4310 xvn[n].xv_dev = dev2udev(vp->v_rdev);
4313 xvn[n].xv_socket = vp->v_socket;
4316 xvn[n].xv_fifo = vp->v_fifoinfo;
4321 /* shouldn't happen? */
4329 mtx_lock(&mountlist_mtx);
4334 mtx_unlock(&mountlist_mtx);
4336 error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
4341 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD |
4342 CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode",
4347 unmount_or_warn(struct mount *mp)
4351 error = dounmount(mp, MNT_FORCE, curthread);
4353 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
4357 printf("%d)\n", error);
4362 * Unmount all filesystems. The list is traversed in reverse order
4363 * of mounting to avoid dependencies.
4366 vfs_unmountall(void)
4368 struct mount *mp, *tmp;
4370 CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
4373 * Since this only runs when rebooting, it is not interlocked.
4375 TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
4379 * Forcibly unmounting "/dev" before "/" would prevent clean
4380 * unmount of the latter.
4382 if (mp == rootdevmp)
4385 unmount_or_warn(mp);
4388 if (rootdevmp != NULL)
4389 unmount_or_warn(rootdevmp);
4393 * perform msync on all vnodes under a mount point
4394 * the mount point must be locked.
4397 vfs_msync(struct mount *mp, int flags)
4399 struct vnode *vp, *mvp;
4400 struct vm_object *obj;
4402 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
4404 if ((mp->mnt_kern_flag & MNTK_NOMSYNC) != 0)
4407 MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
4409 if (obj != NULL && vm_object_mightbedirty(obj) &&
4410 (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
4412 LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
4414 if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
4421 VM_OBJECT_WLOCK(obj);
4422 vm_object_page_clean(obj, 0, 0,
4424 OBJPC_SYNC : OBJPC_NOSYNC);
4425 VM_OBJECT_WUNLOCK(obj);
4435 destroy_vpollinfo_free(struct vpollinfo *vi)
4438 knlist_destroy(&vi->vpi_selinfo.si_note);
4439 mtx_destroy(&vi->vpi_lock);
4440 uma_zfree(vnodepoll_zone, vi);
4444 destroy_vpollinfo(struct vpollinfo *vi)
4447 knlist_clear(&vi->vpi_selinfo.si_note, 1);
4448 seldrain(&vi->vpi_selinfo);
4449 destroy_vpollinfo_free(vi);
4453 * Initialize per-vnode helper structure to hold poll-related state.
4456 v_addpollinfo(struct vnode *vp)
4458 struct vpollinfo *vi;
4460 if (vp->v_pollinfo != NULL)
4462 vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO);
4463 mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
4464 knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
4465 vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
4467 if (vp->v_pollinfo != NULL) {
4469 destroy_vpollinfo_free(vi);
4472 vp->v_pollinfo = vi;
4477 * Record a process's interest in events which might happen to
4478 * a vnode. Because poll uses the historic select-style interface
4479 * internally, this routine serves as both the ``check for any
4480 * pending events'' and the ``record my interest in future events''
4481 * functions. (These are done together, while the lock is held,
4482 * to avoid race conditions.)
4485 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
4489 mtx_lock(&vp->v_pollinfo->vpi_lock);
4490 if (vp->v_pollinfo->vpi_revents & events) {
4492 * This leaves events we are not interested
4493 * in available for the other process which
4494 * which presumably had requested them
4495 * (otherwise they would never have been
4498 events &= vp->v_pollinfo->vpi_revents;
4499 vp->v_pollinfo->vpi_revents &= ~events;
4501 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4504 vp->v_pollinfo->vpi_events |= events;
4505 selrecord(td, &vp->v_pollinfo->vpi_selinfo);
4506 mtx_unlock(&vp->v_pollinfo->vpi_lock);
4511 * Routine to create and manage a filesystem syncer vnode.
4513 #define sync_close ((int (*)(struct vop_close_args *))nullop)
4514 static int sync_fsync(struct vop_fsync_args *);
4515 static int sync_inactive(struct vop_inactive_args *);
4516 static int sync_reclaim(struct vop_reclaim_args *);
4518 static struct vop_vector sync_vnodeops = {
4519 .vop_bypass = VOP_EOPNOTSUPP,
4520 .vop_close = sync_close, /* close */
4521 .vop_fsync = sync_fsync, /* fsync */
4522 .vop_inactive = sync_inactive, /* inactive */
4523 .vop_need_inactive = vop_stdneed_inactive, /* need_inactive */
4524 .vop_reclaim = sync_reclaim, /* reclaim */
4525 .vop_lock1 = vop_stdlock, /* lock */
4526 .vop_unlock = vop_stdunlock, /* unlock */
4527 .vop_islocked = vop_stdislocked, /* islocked */
4531 * Create a new filesystem syncer vnode for the specified mount point.
4534 vfs_allocate_syncvnode(struct mount *mp)
4538 static long start, incr, next;
4541 /* Allocate a new vnode */
4542 error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
4544 panic("vfs_allocate_syncvnode: getnewvnode() failed");
4546 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4547 vp->v_vflag |= VV_FORCEINSMQ;
4548 error = insmntque(vp, mp);
4550 panic("vfs_allocate_syncvnode: insmntque() failed");
4551 vp->v_vflag &= ~VV_FORCEINSMQ;
4554 * Place the vnode onto the syncer worklist. We attempt to
4555 * scatter them about on the list so that they will go off
4556 * at evenly distributed times even if all the filesystems
4557 * are mounted at once.
4560 if (next == 0 || next > syncer_maxdelay) {
4564 start = syncer_maxdelay / 2;
4565 incr = syncer_maxdelay;
4571 vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
4572 /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
4573 mtx_lock(&sync_mtx);
4575 if (mp->mnt_syncer == NULL) {
4576 mp->mnt_syncer = vp;
4579 mtx_unlock(&sync_mtx);
4582 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4589 vfs_deallocate_syncvnode(struct mount *mp)
4593 mtx_lock(&sync_mtx);
4594 vp = mp->mnt_syncer;
4596 mp->mnt_syncer = NULL;
4597 mtx_unlock(&sync_mtx);
4603 * Do a lazy sync of the filesystem.
4606 sync_fsync(struct vop_fsync_args *ap)
4608 struct vnode *syncvp = ap->a_vp;
4609 struct mount *mp = syncvp->v_mount;
4614 * We only need to do something if this is a lazy evaluation.
4616 if (ap->a_waitfor != MNT_LAZY)
4620 * Move ourselves to the back of the sync list.
4622 bo = &syncvp->v_bufobj;
4624 vn_syncer_add_to_worklist(bo, syncdelay);
4628 * Walk the list of vnodes pushing all that are dirty and
4629 * not already on the sync list.
4631 if (vfs_busy(mp, MBF_NOWAIT) != 0)
4633 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
4637 save = curthread_pflags_set(TDP_SYNCIO);
4639 * The filesystem at hand may be idle with free vnodes stored in the
4640 * batch. Return them instead of letting them stay there indefinitely.
4642 vnlru_return_batch(mp);
4643 vfs_msync(mp, MNT_NOWAIT);
4644 error = VFS_SYNC(mp, MNT_LAZY);
4645 curthread_pflags_restore(save);
4646 vn_finished_write(mp);
4652 * The syncer vnode is no referenced.
4655 sync_inactive(struct vop_inactive_args *ap)
4663 * The syncer vnode is no longer needed and is being decommissioned.
4665 * Modifications to the worklist must be protected by sync_mtx.
4668 sync_reclaim(struct vop_reclaim_args *ap)
4670 struct vnode *vp = ap->a_vp;
4675 mtx_lock(&sync_mtx);
4676 if (vp->v_mount->mnt_syncer == vp)
4677 vp->v_mount->mnt_syncer = NULL;
4678 if (bo->bo_flag & BO_ONWORKLST) {
4679 LIST_REMOVE(bo, bo_synclist);
4680 syncer_worklist_len--;
4682 bo->bo_flag &= ~BO_ONWORKLST;
4684 mtx_unlock(&sync_mtx);
4691 vn_need_pageq_flush(struct vnode *vp)
4693 struct vm_object *obj;
4696 MPASS(mtx_owned(VI_MTX(vp)));
4698 if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 &&
4699 vm_object_mightbedirty(obj))
4705 * Check if vnode represents a disk device
4708 vn_isdisk(struct vnode *vp, int *errp)
4712 if (vp->v_type != VCHR) {
4718 if (vp->v_rdev == NULL)
4720 else if (vp->v_rdev->si_devsw == NULL)
4722 else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
4728 return (error == 0);
4732 * Common filesystem object access control check routine. Accepts a
4733 * vnode's type, "mode", uid and gid, requested access mode, credentials,
4734 * and optional call-by-reference privused argument allowing vaccess()
4735 * to indicate to the caller whether privilege was used to satisfy the
4736 * request (obsoleted). Returns 0 on success, or an errno on failure.
4739 vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
4740 accmode_t accmode, struct ucred *cred, int *privused)
4742 accmode_t dac_granted;
4743 accmode_t priv_granted;
4745 KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
4746 ("invalid bit in accmode"));
4747 KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
4748 ("VAPPEND without VWRITE"));
4751 * Look for a normal, non-privileged way to access the file/directory
4752 * as requested. If it exists, go with that.
4755 if (privused != NULL)
4760 /* Check the owner. */
4761 if (cred->cr_uid == file_uid) {
4762 dac_granted |= VADMIN;
4763 if (file_mode & S_IXUSR)
4764 dac_granted |= VEXEC;
4765 if (file_mode & S_IRUSR)
4766 dac_granted |= VREAD;
4767 if (file_mode & S_IWUSR)
4768 dac_granted |= (VWRITE | VAPPEND);
4770 if ((accmode & dac_granted) == accmode)
4776 /* Otherwise, check the groups (first match) */
4777 if (groupmember(file_gid, cred)) {
4778 if (file_mode & S_IXGRP)
4779 dac_granted |= VEXEC;
4780 if (file_mode & S_IRGRP)
4781 dac_granted |= VREAD;
4782 if (file_mode & S_IWGRP)
4783 dac_granted |= (VWRITE | VAPPEND);
4785 if ((accmode & dac_granted) == accmode)
4791 /* Otherwise, check everyone else. */
4792 if (file_mode & S_IXOTH)
4793 dac_granted |= VEXEC;
4794 if (file_mode & S_IROTH)
4795 dac_granted |= VREAD;
4796 if (file_mode & S_IWOTH)
4797 dac_granted |= (VWRITE | VAPPEND);
4798 if ((accmode & dac_granted) == accmode)
4803 * Build a privilege mask to determine if the set of privileges
4804 * satisfies the requirements when combined with the granted mask
4805 * from above. For each privilege, if the privilege is required,
4806 * bitwise or the request type onto the priv_granted mask.
4812 * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
4813 * requests, instead of PRIV_VFS_EXEC.
4815 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4816 !priv_check_cred(cred, PRIV_VFS_LOOKUP))
4817 priv_granted |= VEXEC;
4820 * Ensure that at least one execute bit is on. Otherwise,
4821 * a privileged user will always succeed, and we don't want
4822 * this to happen unless the file really is executable.
4824 if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
4825 (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
4826 !priv_check_cred(cred, PRIV_VFS_EXEC))
4827 priv_granted |= VEXEC;
4830 if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
4831 !priv_check_cred(cred, PRIV_VFS_READ))
4832 priv_granted |= VREAD;
4834 if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
4835 !priv_check_cred(cred, PRIV_VFS_WRITE))
4836 priv_granted |= (VWRITE | VAPPEND);
4838 if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
4839 !priv_check_cred(cred, PRIV_VFS_ADMIN))
4840 priv_granted |= VADMIN;
4842 if ((accmode & (priv_granted | dac_granted)) == accmode) {
4843 /* XXX audit: privilege used */
4844 if (privused != NULL)
4849 return ((accmode & VADMIN) ? EPERM : EACCES);
4853 * Credential check based on process requesting service, and per-attribute
4857 extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
4858 struct thread *td, accmode_t accmode)
4862 * Kernel-invoked always succeeds.
4868 * Do not allow privileged processes in jail to directly manipulate
4869 * system attributes.
4871 switch (attrnamespace) {
4872 case EXTATTR_NAMESPACE_SYSTEM:
4873 /* Potentially should be: return (EPERM); */
4874 return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM));
4875 case EXTATTR_NAMESPACE_USER:
4876 return (VOP_ACCESS(vp, accmode, cred, td));
4882 #ifdef DEBUG_VFS_LOCKS
4884 * This only exists to suppress warnings from unlocked specfs accesses. It is
4885 * no longer ok to have an unlocked VFS.
4887 #define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
4888 (vp)->v_type == VCHR || (vp)->v_type == VBAD)
4890 int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
4891 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
4892 "Drop into debugger on lock violation");
4894 int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
4895 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
4896 0, "Check for interlock across VOPs");
4898 int vfs_badlock_print = 1; /* Print lock violations. */
4899 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
4900 0, "Print lock violations");
4902 int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
4903 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
4904 0, "Print vnode details on lock violations");
4907 int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
4908 SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
4909 &vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
4913 vfs_badlock(const char *msg, const char *str, struct vnode *vp)
4917 if (vfs_badlock_backtrace)
4920 if (vfs_badlock_vnode)
4921 vn_printf(vp, "vnode ");
4922 if (vfs_badlock_print)
4923 printf("%s: %p %s\n", str, (void *)vp, msg);
4924 if (vfs_badlock_ddb)
4925 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
4929 assert_vi_locked(struct vnode *vp, const char *str)
4932 if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
4933 vfs_badlock("interlock is not locked but should be", str, vp);
4937 assert_vi_unlocked(struct vnode *vp, const char *str)
4940 if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
4941 vfs_badlock("interlock is locked but should not be", str, vp);
4945 assert_vop_locked(struct vnode *vp, const char *str)
4949 if (!IGNORE_LOCK(vp)) {
4950 locked = VOP_ISLOCKED(vp);
4951 if (locked == 0 || locked == LK_EXCLOTHER)
4952 vfs_badlock("is not locked but should be", str, vp);
4957 assert_vop_unlocked(struct vnode *vp, const char *str)
4960 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
4961 vfs_badlock("is locked but should not be", str, vp);
4965 assert_vop_elocked(struct vnode *vp, const char *str)
4968 if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
4969 vfs_badlock("is not exclusive locked but should be", str, vp);
4971 #endif /* DEBUG_VFS_LOCKS */
4974 vop_rename_fail(struct vop_rename_args *ap)
4977 if (ap->a_tvp != NULL)
4979 if (ap->a_tdvp == ap->a_tvp)
4988 vop_rename_pre(void *ap)
4990 struct vop_rename_args *a = ap;
4992 #ifdef DEBUG_VFS_LOCKS
4994 ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
4995 ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
4996 ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
4997 ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
4999 /* Check the source (from). */
5000 if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
5001 (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
5002 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
5003 if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
5004 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
5006 /* Check the target. */
5008 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
5009 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
5011 if (a->a_tdvp != a->a_fdvp)
5013 if (a->a_tvp != a->a_fvp)
5020 #ifdef DEBUG_VFS_LOCKS
5022 vop_strategy_pre(void *ap)
5024 struct vop_strategy_args *a;
5031 * Cluster ops lock their component buffers but not the IO container.
5033 if ((bp->b_flags & B_CLUSTER) != 0)
5036 if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
5037 if (vfs_badlock_print)
5039 "VOP_STRATEGY: bp is not locked but should be\n");
5040 if (vfs_badlock_ddb)
5041 kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
5046 vop_lock_pre(void *ap)
5048 struct vop_lock1_args *a = ap;
5050 if ((a->a_flags & LK_INTERLOCK) == 0)
5051 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
5053 ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
5057 vop_lock_post(void *ap, int rc)
5059 struct vop_lock1_args *a = ap;
5061 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
5062 if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
5063 ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
5067 vop_unlock_pre(void *ap)
5069 struct vop_unlock_args *a = ap;
5071 if (a->a_flags & LK_INTERLOCK)
5072 ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
5073 ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
5077 vop_unlock_post(void *ap, int rc)
5079 struct vop_unlock_args *a = ap;
5081 if (a->a_flags & LK_INTERLOCK)
5082 ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
5086 vop_need_inactive_pre(void *ap)
5088 struct vop_need_inactive_args *a = ap;
5090 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
5094 vop_need_inactive_post(void *ap, int rc)
5096 struct vop_need_inactive_args *a = ap;
5098 ASSERT_VI_LOCKED(a->a_vp, "VOP_NEED_INACTIVE");
5103 vop_create_post(void *ap, int rc)
5105 struct vop_create_args *a = ap;
5108 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
5112 vop_deleteextattr_post(void *ap, int rc)
5114 struct vop_deleteextattr_args *a = ap;
5117 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
5121 vop_link_post(void *ap, int rc)
5123 struct vop_link_args *a = ap;
5126 VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
5127 VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
5132 vop_mkdir_post(void *ap, int rc)
5134 struct vop_mkdir_args *a = ap;
5137 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
5141 vop_mknod_post(void *ap, int rc)
5143 struct vop_mknod_args *a = ap;
5146 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
5150 vop_reclaim_post(void *ap, int rc)
5152 struct vop_reclaim_args *a = ap;
5155 VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE);
5159 vop_remove_post(void *ap, int rc)
5161 struct vop_remove_args *a = ap;
5164 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
5165 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
5170 vop_rename_post(void *ap, int rc)
5172 struct vop_rename_args *a = ap;
5177 if (a->a_fdvp == a->a_tdvp) {
5178 if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
5180 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
5181 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
5183 hint |= NOTE_EXTEND;
5184 if (a->a_fvp->v_type == VDIR)
5186 VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
5188 if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
5189 a->a_tvp->v_type == VDIR)
5191 VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
5194 VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
5196 VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
5198 if (a->a_tdvp != a->a_fdvp)
5200 if (a->a_tvp != a->a_fvp)
5208 vop_rmdir_post(void *ap, int rc)
5210 struct vop_rmdir_args *a = ap;
5213 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
5214 VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
5219 vop_setattr_post(void *ap, int rc)
5221 struct vop_setattr_args *a = ap;
5224 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
5228 vop_setextattr_post(void *ap, int rc)
5230 struct vop_setextattr_args *a = ap;
5233 VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
5237 vop_symlink_post(void *ap, int rc)
5239 struct vop_symlink_args *a = ap;
5242 VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
5246 vop_open_post(void *ap, int rc)
5248 struct vop_open_args *a = ap;
5251 VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
5255 vop_close_post(void *ap, int rc)
5257 struct vop_close_args *a = ap;
5259 if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
5260 (a->a_vp->v_iflag & VI_DOOMED) == 0)) {
5261 VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
5262 NOTE_CLOSE_WRITE : NOTE_CLOSE);
5267 vop_read_post(void *ap, int rc)
5269 struct vop_read_args *a = ap;
5272 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
5276 vop_readdir_post(void *ap, int rc)
5278 struct vop_readdir_args *a = ap;
5281 VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
5284 static struct knlist fs_knlist;
5287 vfs_event_init(void *arg)
5289 knlist_init_mtx(&fs_knlist, NULL);
5291 /* XXX - correct order? */
5292 SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
5295 vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
5298 KNOTE_UNLOCKED(&fs_knlist, event);
5301 static int filt_fsattach(struct knote *kn);
5302 static void filt_fsdetach(struct knote *kn);
5303 static int filt_fsevent(struct knote *kn, long hint);
5305 struct filterops fs_filtops = {
5307 .f_attach = filt_fsattach,
5308 .f_detach = filt_fsdetach,
5309 .f_event = filt_fsevent
5313 filt_fsattach(struct knote *kn)
5316 kn->kn_flags |= EV_CLEAR;
5317 knlist_add(&fs_knlist, kn, 0);
5322 filt_fsdetach(struct knote *kn)
5325 knlist_remove(&fs_knlist, kn, 0);
5329 filt_fsevent(struct knote *kn, long hint)
5332 kn->kn_fflags |= hint;
5333 return (kn->kn_fflags != 0);
5337 sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
5343 error = SYSCTL_IN(req, &vc, sizeof(vc));
5346 if (vc.vc_vers != VFS_CTL_VERS1)
5348 mp = vfs_getvfs(&vc.vc_fsid);
5351 /* ensure that a specific sysctl goes to the right filesystem. */
5352 if (strcmp(vc.vc_fstypename, "*") != 0 &&
5353 strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
5357 VCTLTOREQ(&vc, req);
5358 error = VFS_SYSCTL(mp, vc.vc_op, req);
5363 SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
5364 NULL, 0, sysctl_vfs_ctl, "",
5368 * Function to initialize a va_filerev field sensibly.
5369 * XXX: Wouldn't a random number make a lot more sense ??
5372 init_va_filerev(void)
5377 return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
5380 static int filt_vfsread(struct knote *kn, long hint);
5381 static int filt_vfswrite(struct knote *kn, long hint);
5382 static int filt_vfsvnode(struct knote *kn, long hint);
5383 static void filt_vfsdetach(struct knote *kn);
5384 static struct filterops vfsread_filtops = {
5386 .f_detach = filt_vfsdetach,
5387 .f_event = filt_vfsread
5389 static struct filterops vfswrite_filtops = {
5391 .f_detach = filt_vfsdetach,
5392 .f_event = filt_vfswrite
5394 static struct filterops vfsvnode_filtops = {
5396 .f_detach = filt_vfsdetach,
5397 .f_event = filt_vfsvnode
5401 vfs_knllock(void *arg)
5403 struct vnode *vp = arg;
5405 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
5409 vfs_knlunlock(void *arg)
5411 struct vnode *vp = arg;
5417 vfs_knl_assert_locked(void *arg)
5419 #ifdef DEBUG_VFS_LOCKS
5420 struct vnode *vp = arg;
5422 ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
5427 vfs_knl_assert_unlocked(void *arg)
5429 #ifdef DEBUG_VFS_LOCKS
5430 struct vnode *vp = arg;
5432 ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
5437 vfs_kqfilter(struct vop_kqfilter_args *ap)
5439 struct vnode *vp = ap->a_vp;
5440 struct knote *kn = ap->a_kn;
5443 switch (kn->kn_filter) {
5445 kn->kn_fop = &vfsread_filtops;
5448 kn->kn_fop = &vfswrite_filtops;
5451 kn->kn_fop = &vfsvnode_filtops;
5457 kn->kn_hook = (caddr_t)vp;
5460 if (vp->v_pollinfo == NULL)
5462 knl = &vp->v_pollinfo->vpi_selinfo.si_note;
5464 knlist_add(knl, kn, 0);
5470 * Detach knote from vnode
5473 filt_vfsdetach(struct knote *kn)
5475 struct vnode *vp = (struct vnode *)kn->kn_hook;
5477 KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
5478 knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
5484 filt_vfsread(struct knote *kn, long hint)
5486 struct vnode *vp = (struct vnode *)kn->kn_hook;
5491 * filesystem is gone, so set the EOF flag and schedule
5492 * the knote for deletion.
5494 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
5496 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
5501 if (VOP_GETATTR(vp, &va, curthread->td_ucred))
5505 kn->kn_data = va.va_size - kn->kn_fp->f_offset;
5506 res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
5513 filt_vfswrite(struct knote *kn, long hint)
5515 struct vnode *vp = (struct vnode *)kn->kn_hook;
5520 * filesystem is gone, so set the EOF flag and schedule
5521 * the knote for deletion.
5523 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
5524 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
5532 filt_vfsvnode(struct knote *kn, long hint)
5534 struct vnode *vp = (struct vnode *)kn->kn_hook;
5538 if (kn->kn_sfflags & hint)
5539 kn->kn_fflags |= hint;
5540 if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
5541 kn->kn_flags |= EV_EOF;
5545 res = (kn->kn_fflags != 0);
5551 * Returns whether the directory is empty or not.
5552 * If it is empty, the return value is 0; otherwise
5553 * the return value is an error value (which may
5557 vfs_emptydir(struct vnode *vp)
5561 struct dirent *dirent, *dp, *endp;
5567 ASSERT_VOP_LOCKED(vp, "vfs_emptydir");
5569 dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK);
5570 iov.iov_base = dirent;
5571 iov.iov_len = sizeof(struct dirent);
5576 uio.uio_resid = sizeof(struct dirent);
5577 uio.uio_segflg = UIO_SYSSPACE;
5578 uio.uio_rw = UIO_READ;
5579 uio.uio_td = curthread;
5581 while (eof == 0 && error == 0) {
5582 error = VOP_READDIR(vp, &uio, curthread->td_ucred, &eof,
5586 endp = (void *)((uint8_t *)dirent +
5587 sizeof(struct dirent) - uio.uio_resid);
5588 for (dp = dirent; dp < endp;
5589 dp = (void *)((uint8_t *)dp + GENERIC_DIRSIZ(dp))) {
5590 if (dp->d_type == DT_WHT)
5592 if (dp->d_namlen == 0)
5594 if (dp->d_type != DT_DIR &&
5595 dp->d_type != DT_UNKNOWN) {
5599 if (dp->d_namlen > 2) {
5603 if (dp->d_namlen == 1 &&
5604 dp->d_name[0] != '.') {
5608 if (dp->d_namlen == 2 &&
5609 dp->d_name[1] != '.') {
5613 uio.uio_resid = sizeof(struct dirent);
5616 free(dirent, M_TEMP);
5621 vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
5625 if (dp->d_reclen > ap->a_uio->uio_resid)
5626 return (ENAMETOOLONG);
5627 error = uiomove(dp, dp->d_reclen, ap->a_uio);
5629 if (ap->a_ncookies != NULL) {
5630 if (ap->a_cookies != NULL)
5631 free(ap->a_cookies, M_TEMP);
5632 ap->a_cookies = NULL;
5633 *ap->a_ncookies = 0;
5637 if (ap->a_ncookies == NULL)
5640 KASSERT(ap->a_cookies,
5641 ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
5643 *ap->a_cookies = realloc(*ap->a_cookies,
5644 (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
5645 (*ap->a_cookies)[*ap->a_ncookies] = off;
5646 *ap->a_ncookies += 1;
5651 * Mark for update the access time of the file if the filesystem
5652 * supports VOP_MARKATIME. This functionality is used by execve and
5653 * mmap, so we want to avoid the I/O implied by directly setting
5654 * va_atime for the sake of efficiency.
5657 vfs_mark_atime(struct vnode *vp, struct ucred *cred)
5662 ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
5663 if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
5664 (void)VOP_MARKATIME(vp);
5668 * The purpose of this routine is to remove granularity from accmode_t,
5669 * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
5670 * VADMIN and VAPPEND.
5672 * If it returns 0, the caller is supposed to continue with the usual
5673 * access checks using 'accmode' as modified by this routine. If it
5674 * returns nonzero value, the caller is supposed to return that value
5677 * Note that after this routine runs, accmode may be zero.
5680 vfs_unixify_accmode(accmode_t *accmode)
5683 * There is no way to specify explicit "deny" rule using
5684 * file mode or POSIX.1e ACLs.
5686 if (*accmode & VEXPLICIT_DENY) {
5692 * None of these can be translated into usual access bits.
5693 * Also, the common case for NFSv4 ACLs is to not contain
5694 * either of these bits. Caller should check for VWRITE
5695 * on the containing directory instead.
5697 if (*accmode & (VDELETE_CHILD | VDELETE))
5700 if (*accmode & VADMIN_PERMS) {
5701 *accmode &= ~VADMIN_PERMS;
5706 * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
5707 * or VSYNCHRONIZE using file mode or POSIX.1e ACL.
5709 *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
5715 * Clear out a doomed vnode (if any) and replace it with a new one as long
5716 * as the fs is not being unmounted. Return the root vnode to the caller.
5718 static int __noinline
5719 vfs_cache_root_fallback(struct mount *mp, int flags, struct vnode **vpp)
5725 if (mp->mnt_rootvnode != NULL) {
5727 vp = mp->mnt_rootvnode;
5729 if ((vp->v_iflag & VI_DOOMED) == 0) {
5732 error = vn_lock(vp, flags);
5741 * Clear the old one.
5743 mp->mnt_rootvnode = NULL;
5748 * Paired with a fence in vfs_op_thread_exit().
5750 atomic_thread_fence_acq();
5751 vfs_op_barrier_wait(mp);
5755 error = VFS_CACHEDROOT(mp, flags, vpp);
5758 if (mp->mnt_vfs_ops == 0) {
5760 if (mp->mnt_vfs_ops != 0) {
5764 if (mp->mnt_rootvnode == NULL) {
5766 mp->mnt_rootvnode = *vpp;
5768 if (mp->mnt_rootvnode != *vpp) {
5769 if ((mp->mnt_rootvnode->v_iflag & VI_DOOMED) == 0) {
5770 panic("%s: mismatch between vnode returned "
5771 " by VFS_CACHEDROOT and the one cached "
5773 __func__, *vpp, mp->mnt_rootvnode);
5783 vfs_cache_root(struct mount *mp, int flags, struct vnode **vpp)
5788 if (!vfs_op_thread_enter(mp))
5789 return (vfs_cache_root_fallback(mp, flags, vpp));
5790 vp = (struct vnode *)atomic_load_ptr(&mp->mnt_rootvnode);
5791 if (vp == NULL || (vp->v_iflag & VI_DOOMED)) {
5792 vfs_op_thread_exit(mp);
5793 return (vfs_cache_root_fallback(mp, flags, vpp));
5796 vfs_op_thread_exit(mp);
5797 error = vn_lock(vp, flags);
5800 return (vfs_cache_root_fallback(mp, flags, vpp));
5807 vfs_cache_root_clear(struct mount *mp)
5812 * ops > 0 guarantees there is nobody who can see this vnode
5814 MPASS(mp->mnt_vfs_ops > 0);
5815 vp = mp->mnt_rootvnode;
5816 mp->mnt_rootvnode = NULL;
5821 vfs_cache_root_set(struct mount *mp, struct vnode *vp)
5824 MPASS(mp->mnt_vfs_ops > 0);
5826 mp->mnt_rootvnode = vp;
5830 * These are helper functions for filesystems to traverse all
5831 * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
5833 * This interface replaces MNT_VNODE_FOREACH.
5836 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
5839 __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
5844 kern_yield(PRI_USER);
5846 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5847 for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL;
5848 vp = TAILQ_NEXT(vp, v_nmntvnodes)) {
5849 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */
5850 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0)
5853 if ((vp->v_iflag & VI_DOOMED) != 0) {
5860 __mnt_vnode_markerfree_all(mvp, mp);
5861 /* MNT_IUNLOCK(mp); -- done in above function */
5862 mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
5865 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5866 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5872 __mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
5876 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
5879 (*mvp)->v_mount = mp;
5880 (*mvp)->v_type = VMARKER;
5882 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
5883 /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */
5884 if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0)
5887 if ((vp->v_iflag & VI_DOOMED) != 0) {
5896 free(*mvp, M_VNODE_MARKER);
5900 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
5906 __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
5914 mtx_assert(MNT_MTX(mp), MA_OWNED);
5916 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5917 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
5920 free(*mvp, M_VNODE_MARKER);
5925 * These are helper functions for filesystems to traverse their
5926 * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
5929 mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
5932 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
5937 free(*mvp, M_VNODE_MARKER);
5942 * Relock the mp mount vnode list lock with the vp vnode interlock in the
5943 * conventional lock order during mnt_vnode_next_active iteration.
5945 * On entry, the mount vnode list lock is held and the vnode interlock is not.
5946 * The list lock is dropped and reacquired. On success, both locks are held.
5947 * On failure, the mount vnode list lock is held but the vnode interlock is
5948 * not, and the procedure may have yielded.
5951 mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp,
5954 const struct vnode *tmp;
5957 VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER &&
5958 TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp,
5959 ("%s: bad marker", __func__));
5960 VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp,
5961 ("%s: inappropriate vnode", __func__));
5962 ASSERT_VI_UNLOCKED(vp, __func__);
5963 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
5967 TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist);
5968 TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist);
5971 * Use a hold to prevent vp from disappearing while the mount vnode
5972 * list lock is dropped and reacquired. Normally a hold would be
5973 * acquired with vhold(), but that might try to acquire the vnode
5974 * interlock, which would be a LOR with the mount vnode list lock.
5976 held = refcount_acquire_if_not_zero(&vp->v_holdcnt);
5977 mtx_unlock(&mp->mnt_listmtx);
5981 if (!refcount_release_if_not_last(&vp->v_holdcnt)) {
5985 mtx_lock(&mp->mnt_listmtx);
5988 * Determine whether the vnode is still the next one after the marker,
5989 * excepting any other markers. If the vnode has not been doomed by
5990 * vgone() then the hold should have ensured that it remained on the
5991 * active list. If it has been doomed but is still on the active list,
5992 * don't abort, but rather skip over it (avoid spinning on doomed
5997 tmp = TAILQ_NEXT(tmp, v_actfreelist);
5998 } while (tmp != NULL && tmp->v_type == VMARKER);
6000 mtx_unlock(&mp->mnt_listmtx);
6009 mtx_lock(&mp->mnt_listmtx);
6012 ASSERT_VI_LOCKED(vp, __func__);
6014 ASSERT_VI_UNLOCKED(vp, __func__);
6015 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
6019 static struct vnode *
6020 mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
6022 struct vnode *vp, *nvp;
6024 mtx_assert(&mp->mnt_listmtx, MA_OWNED);
6025 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
6027 vp = TAILQ_NEXT(*mvp, v_actfreelist);
6028 while (vp != NULL) {
6029 if (vp->v_type == VMARKER) {
6030 vp = TAILQ_NEXT(vp, v_actfreelist);
6034 * Try-lock because this is the wrong lock order. If that does
6035 * not succeed, drop the mount vnode list lock and try to
6036 * reacquire it and the vnode interlock in the right order.
6038 if (!VI_TRYLOCK(vp) &&
6039 !mnt_vnode_next_active_relock(*mvp, mp, vp))
6041 KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
6042 KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
6043 ("alien vnode on the active list %p %p", vp, mp));
6044 if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0)
6046 nvp = TAILQ_NEXT(vp, v_actfreelist);
6050 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
6052 /* Check if we are done */
6054 mtx_unlock(&mp->mnt_listmtx);
6055 mnt_vnode_markerfree_active(mvp, mp);
6058 TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
6059 mtx_unlock(&mp->mnt_listmtx);
6060 ASSERT_VI_LOCKED(vp, "active iter");
6061 KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp));
6066 __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
6070 kern_yield(PRI_USER);
6071 mtx_lock(&mp->mnt_listmtx);
6072 return (mnt_vnode_next_active(mvp, mp));
6076 __mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
6080 *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
6084 (*mvp)->v_type = VMARKER;
6085 (*mvp)->v_mount = mp;
6087 mtx_lock(&mp->mnt_listmtx);
6088 vp = TAILQ_FIRST(&mp->mnt_activevnodelist);
6090 mtx_unlock(&mp->mnt_listmtx);
6091 mnt_vnode_markerfree_active(mvp, mp);
6094 TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
6095 return (mnt_vnode_next_active(mvp, mp));
6099 __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
6105 mtx_lock(&mp->mnt_listmtx);
6106 TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
6107 mtx_unlock(&mp->mnt_listmtx);
6108 mnt_vnode_markerfree_active(mvp, mp);