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freebsd-skq/sys/kern/vfs_subr.c
Julian Elischer b1897c197c Reviewed by: dyson@freebsd.org (john Dyson), dg@root.com (david greenman) 
Submitted by:	Kirk McKusick (mcKusick@mckusick.com)
Obtained from:  WHistle development tree
1998-03-08 09:59:44 +00:00

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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
* $Id: vfs_subr.c,v 1.137 1998/03/07 21:35:35 dyson Exp $
*/
/*
* External virtual filesystem routines
*/
#include "opt_ddb.h"
#include "opt_devfs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/poll.h>
#include <sys/domain.h>
#include <sys/dirent.h>
#include <sys/vmmeter.h>
#include <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
#include <vm/vm_zone.h>
#include <sys/sysctl.h>
#include <miscfs/specfs/specdev.h>
static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
static void insmntque __P((struct vnode *vp, struct mount *mp));
#ifdef DDB
static void printlockedvnodes __P((void));
#endif
static void vclean __P((struct vnode *vp, int flags, struct proc *p));
static void vfree __P((struct vnode *));
static void vgonel __P((struct vnode *vp, struct proc *p));
static unsigned long numvnodes;
SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
enum vtype iftovt_tab[16] = {
VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
};
int vttoif_tab[9] = {
0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
S_IFSOCK, S_IFIFO, S_IFMT,
};
/*
* Insq/Remq for the vnode usage lists.
*/
#define bufinsvn(bp, dp) LIST_INSERT_HEAD(dp, bp, b_vnbufs)
#define bufremvn(bp) { \
LIST_REMOVE(bp, b_vnbufs); \
(bp)->b_vnbufs.le_next = NOLIST; \
}
static TAILQ_HEAD(freelst, vnode) vnode_free_list; /* vnode free list */
struct tobefreelist vnode_tobefree_list; /* vnode free list */
static u_long wantfreevnodes = 25;
SYSCTL_INT(_debug, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
static u_long freevnodes = 0;
SYSCTL_INT(_debug, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
int vfs_ioopt = 0;
SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
struct mntlist mountlist; /* mounted filesystem list */
struct simplelock mountlist_slock;
static struct simplelock mntid_slock;
struct simplelock mntvnode_slock;
static struct simplelock vnode_free_list_slock;
static struct simplelock spechash_slock;
struct nfs_public nfs_pub; /* publicly exported FS */
static vm_zone_t vnode_zone;
/*
* The workitem queue.
*/
#define SYNCER_MAXDELAY 32
int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
time_t syncdelay = 30;
int rushjob; /* number of slots to run ASAP */
static int syncer_delayno = 0;
static long syncer_mask;
LIST_HEAD(synclist, vnode);
static struct synclist *syncer_workitem_pending;
int desiredvnodes;
SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, &desiredvnodes, 0, "");
static void vfs_free_addrlist __P((struct netexport *nep));
static int vfs_free_netcred __P((struct radix_node *rn, void *w));
static int vfs_hang_addrlist __P((struct mount *mp, struct netexport *nep,
struct export_args *argp));
/*
* Initialize the vnode management data structures.
*/
void
vntblinit()
{
desiredvnodes = maxproc + cnt.v_page_count / 4;
simple_lock_init(&mntvnode_slock);
simple_lock_init(&mntid_slock);
simple_lock_init(&spechash_slock);
TAILQ_INIT(&vnode_free_list);
TAILQ_INIT(&vnode_tobefree_list);
simple_lock_init(&vnode_free_list_slock);
CIRCLEQ_INIT(&mountlist);
vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5);
/*
* Initialize the filesystem syncer.
*/
syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
&syncer_mask);
syncer_maxdelay = syncer_mask + 1;
}
/*
* Mark a mount point as busy. Used to synchronize access and to delay
* unmounting. Interlock is not released on failure.
*/
int
vfs_busy(mp, flags, interlkp, p)
struct mount *mp;
int flags;
struct simplelock *interlkp;
struct proc *p;
{
int lkflags;
if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
if (flags & LK_NOWAIT)
return (ENOENT);
mp->mnt_kern_flag |= MNTK_MWAIT;
if (interlkp) {
simple_unlock(interlkp);
}
/*
* Since all busy locks are shared except the exclusive
* lock granted when unmounting, the only place that a
* wakeup needs to be done is at the release of the
* exclusive lock at the end of dounmount.
*/
tsleep((caddr_t)mp, PVFS, "vfs_busy", 0);
if (interlkp) {
simple_lock(interlkp);
}
return (ENOENT);
}
lkflags = LK_SHARED | LK_NOPAUSE;
if (interlkp)
lkflags |= LK_INTERLOCK;
if (lockmgr(&mp->mnt_lock, lkflags, interlkp, p))
panic("vfs_busy: unexpected lock failure");
return (0);
}
/*
* Free a busy filesystem.
*/
void
vfs_unbusy(mp, p)
struct mount *mp;
struct proc *p;
{
lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, p);
}
/*
* Lookup a filesystem type, and if found allocate and initialize
* a mount structure for it.
*
* Devname is usually updated by mount(8) after booting.
*/
int
vfs_rootmountalloc(fstypename, devname, mpp)
char *fstypename;
char *devname;
struct mount **mpp;
{
struct proc *p = curproc; /* XXX */
struct vfsconf *vfsp;
struct mount *mp;
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstypename))
break;
if (vfsp == NULL)
return (ENODEV);
mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
bzero((char *)mp, (u_long)sizeof(struct mount));
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
(void)vfs_busy(mp, LK_NOWAIT, 0, p);
LIST_INIT(&mp->mnt_vnodelist);
mp->mnt_vfc = vfsp;
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_flag = MNT_RDONLY;
mp->mnt_vnodecovered = NULLVP;
vfsp->vfc_refcount++;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_stat.f_mntonname[0] = '/';
mp->mnt_stat.f_mntonname[1] = 0;
(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
*mpp = mp;
return (0);
}
/*
* Find an appropriate filesystem to use for the root. If a filesystem
* has not been preselected, walk through the list of known filesystems
* trying those that have mountroot routines, and try them until one
* works or we have tried them all.
*/
#ifdef notdef /* XXX JH */
int
lite2_vfs_mountroot()
{
struct vfsconf *vfsp;
extern int (*lite2_mountroot) __P((void));
int error;
if (lite2_mountroot != NULL)
return ((*lite2_mountroot)());
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
if (vfsp->vfc_mountroot == NULL)
continue;
if ((error = (*vfsp->vfc_mountroot)()) == 0)
return (0);
printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error);
}
return (ENODEV);
}
#endif
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
vfs_getvfs(fsid)
fsid_t *fsid;
{
register struct mount *mp;
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist;
mp = mp->mnt_list.cqe_next) {
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
simple_unlock(&mountlist_slock);
return (mp);
}
}
simple_unlock(&mountlist_slock);
return ((struct mount *) 0);
}
/*
* Get a new unique fsid
*/
void
vfs_getnewfsid(mp)
struct mount *mp;
{
static u_short xxxfs_mntid;
fsid_t tfsid;
int mtype;
simple_lock(&mntid_slock);
mtype = mp->mnt_vfc->vfc_typenum;
mp->mnt_stat.f_fsid.val[0] = makedev(nblkdev + mtype, 0);
mp->mnt_stat.f_fsid.val[1] = mtype;
if (xxxfs_mntid == 0)
++xxxfs_mntid;
tfsid.val[0] = makedev(nblkdev + mtype, xxxfs_mntid);
tfsid.val[1] = mtype;
if (mountlist.cqh_first != (void *)&mountlist) {
while (vfs_getvfs(&tfsid)) {
tfsid.val[0]++;
xxxfs_mntid++;
}
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
simple_unlock(&mntid_slock);
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
vap->va_size = VNOVAL;
vap->va_bytes = VNOVAL;
vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid =
vap->va_fsid = vap->va_fileid =
vap->va_blocksize = vap->va_rdev =
vap->va_atime.tv_sec = vap->va_atime.tv_nsec =
vap->va_mtime.tv_sec = vap->va_mtime.tv_nsec =
vap->va_ctime.tv_sec = vap->va_ctime.tv_nsec =
vap->va_flags = vap->va_gen = VNOVAL;
vap->va_vaflags = 0;
}
/*
* Routines having to do with the management of the vnode table.
*/
extern vop_t **dead_vnodeop_p;
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
vop_t **vops;
struct vnode **vpp;
{
int s;
struct proc *p = curproc; /* XXX */
struct vnode *vp, *tvp, *nvp;
vm_object_t object;
TAILQ_HEAD(freelst, vnode) vnode_tmp_list;
/*
* We take the least recently used vnode from the freelist
* if we can get it and it has no cached pages, and no
* namecache entries are relative to it.
* Otherwise we allocate a new vnode
*/
s = splbio();
simple_lock(&vnode_free_list_slock);
TAILQ_INIT(&vnode_tmp_list);
for (vp = TAILQ_FIRST(&vnode_tobefree_list); vp; vp = nvp) {
nvp = TAILQ_NEXT(vp, v_freelist);
TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist);
if (vp->v_flag & VAGE) {
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
} else {
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
vp->v_flag &= ~(VTBFREE|VAGE);
vp->v_flag |= VFREE;
if (vp->v_usecount)
panic("tobe free vnode isn't");
freevnodes++;
}
if (wantfreevnodes && freevnodes < wantfreevnodes) {
vp = NULL;
} else if (!wantfreevnodes && freevnodes <= desiredvnodes) {
/*
* XXX: this is only here to be backwards compatible
*/
vp = NULL;
} else {
for (vp = TAILQ_FIRST(&vnode_free_list); vp; vp = nvp) {
nvp = TAILQ_NEXT(vp, v_freelist);
if (!simple_lock_try(&vp->v_interlock))
continue;
if (vp->v_usecount)
panic("free vnode isn't");
object = vp->v_object;
if (object && (object->resident_page_count || object->ref_count)) {
printf("object inconsistant state: RPC: %d, RC: %d\n",
object->resident_page_count, object->ref_count);
/* Don't recycle if it's caching some pages */
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
TAILQ_INSERT_TAIL(&vnode_tmp_list, vp, v_freelist);
continue;
} else if (LIST_FIRST(&vp->v_cache_src)) {
/* Don't recycle if active in the namecache */
simple_unlock(&vp->v_interlock);
continue;
} else {
break;
}
}
}
for (tvp = TAILQ_FIRST(&vnode_tmp_list); tvp; tvp = nvp) {
nvp = TAILQ_NEXT(tvp, v_freelist);
TAILQ_REMOVE(&vnode_tmp_list, tvp, v_freelist);
TAILQ_INSERT_TAIL(&vnode_free_list, tvp, v_freelist);
simple_unlock(&tvp->v_interlock);
}
if (vp) {
vp->v_flag |= VDOOMED;
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
freevnodes--;
simple_unlock(&vnode_free_list_slock);
cache_purge(vp);
vp->v_lease = NULL;
if (vp->v_type != VBAD) {
vgonel(vp, p);
} else {
simple_unlock(&vp->v_interlock);
}
#ifdef DIAGNOSTIC
{
int s;
if (vp->v_data)
panic("cleaned vnode isn't");
s = splbio();
if (vp->v_numoutput)
panic("Clean vnode has pending I/O's");
splx(s);
}
#endif
vp->v_flag = 0;
vp->v_lastr = 0;
vp->v_lastw = 0;
vp->v_lasta = 0;
vp->v_cstart = 0;
vp->v_clen = 0;
vp->v_socket = 0;
vp->v_writecount = 0; /* XXX */
vp->v_maxio = 0;
} else {
simple_unlock(&vnode_free_list_slock);
vp = (struct vnode *) zalloc(vnode_zone);
bzero((char *) vp, sizeof *vp);
simple_lock_init(&vp->v_interlock);
vp->v_dd = vp;
cache_purge(vp);
LIST_INIT(&vp->v_cache_src);
TAILQ_INIT(&vp->v_cache_dst);
numvnodes++;
}
vp->v_type = VNON;
vp->v_tag = tag;
vp->v_op = vops;
insmntque(vp, mp);
*vpp = vp;
vp->v_usecount = 1;
vp->v_data = 0;
splx(s);
vfs_object_create(vp, p, p->p_ucred, TRUE);
return (0);
}
/*
* Move a vnode from one mount queue to another.
*/
static void
insmntque(vp, mp)
register struct vnode *vp;
register struct mount *mp;
{
simple_lock(&mntvnode_slock);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
LIST_REMOVE(vp, v_mntvnodes);
/*
* Insert into list of vnodes for the new mount point, if available.
*/
if ((vp->v_mount = mp) == NULL) {
simple_unlock(&mntvnode_slock);
return;
}
LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes);
simple_unlock(&mntvnode_slock);
}
/*
* Update outstanding I/O count and do wakeup if requested.
*/
void
vwakeup(bp)
register struct buf *bp;
{
register struct vnode *vp;
bp->b_flags &= ~B_WRITEINPROG;
if ((vp = bp->b_vp)) {
vp->v_numoutput--;
if (vp->v_numoutput < 0)
panic("vwakeup: neg numoutput");
if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t) &vp->v_numoutput);
}
}
}
/*
* Flush out and invalidate all buffers associated with a vnode.
* Called with the underlying object locked.
*/
int
vinvalbuf(vp, flags, cred, p, slpflag, slptimeo)
register struct vnode *vp;
int flags;
struct ucred *cred;
struct proc *p;
int slpflag, slptimeo;
{
register struct buf *bp;
struct buf *nbp, *blist;
int s, error;
vm_object_t object;
if ((flags & V_SAVE) && vp->v_dirtyblkhd.lh_first != NULL) {
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)))
return (error);
if (vp->v_dirtyblkhd.lh_first != NULL)
panic("vinvalbuf: dirty bufs");
}
s = splbio();
for (;;) {
if ((blist = vp->v_cleanblkhd.lh_first) && (flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist && (blist = vp->v_dirtyblkhd.lh_first) &&
(flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist)
break;
for (bp = blist; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;
if ((flags & V_SAVEMETA) && bp->b_lblkno < 0)
continue;
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
error = tsleep((caddr_t) bp,
slpflag | (PRIBIO + 1), "vinvalbuf",
slptimeo);
if (error) {
splx(s);
return (error);
}
break;
}
bremfree(bp);
bp->b_flags |= B_BUSY;
/*
* XXX Since there are no node locks for NFS, I
* believe there is a slight chance that a delayed
* write will occur while sleeping just above, so
* check for it.
*/
if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) {
if (bp->b_vp == vp) {
if (bp->b_flags & B_CLUSTEROK) {
vfs_bio_awrite(bp);
} else {
bp->b_flags |= B_ASYNC;
VOP_BWRITE(bp);
}
} else {
(void) VOP_BWRITE(bp);
}
break;
}
bp->b_flags |= (B_INVAL|B_NOCACHE|B_RELBUF);
brelse(bp);
}
}
while (vp->v_numoutput > 0) {
vp->v_flag |= VBWAIT;
tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0);
}
splx(s);
/*
* Destroy the copy in the VM cache, too.
*/
simple_lock(&vp->v_interlock);
object = vp->v_object;
if (object != NULL) {
if (flags & V_SAVEMETA)
vm_object_page_remove(object, 0, object->size,
(flags & V_SAVE) ? TRUE : FALSE);
else
vm_object_page_remove(object, 0, 0,
(flags & V_SAVE) ? TRUE : FALSE);
}
simple_unlock(&vp->v_interlock);
if (!(flags & V_SAVEMETA) &&
(vp->v_dirtyblkhd.lh_first || vp->v_cleanblkhd.lh_first))
panic("vinvalbuf: flush failed");
return (0);
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
int s;
#if defined(DIAGNOSTIC)
if (bp->b_vp)
panic("bgetvp: not free");
#endif
vhold(vp);
bp->b_vp = vp;
if (vp->v_type == VBLK || vp->v_type == VCHR)
bp->b_dev = vp->v_rdev;
else
bp->b_dev = NODEV;
/*
* Insert onto list for new vnode.
*/
s = splbio();
bufinsvn(bp, &vp->v_cleanblkhd);
splx(s);
}
/*
* Disassociate a buffer from a vnode.
*/
void
brelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
int s;
#if defined(DIAGNOSTIC)
if (bp->b_vp == (struct vnode *) 0)
panic("brelvp: NULL");
#endif
/*
* Delete from old vnode list, if on one.
*/
vp = bp->b_vp;
s = splbio();
if (bp->b_vnbufs.le_next != NOLIST)
bufremvn(bp);
if ((vp->v_flag & VONWORKLST) && (LIST_FIRST(&vp->v_dirtyblkhd) == NULL)) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
splx(s);
bp->b_vp = (struct vnode *) 0;
vdrop(vp);
}
/*
* The workitem queue.
*
* It is useful to delay writes of file data and filesystem metadata
* for tens of seconds so that quickly created and deleted files need
* not waste disk bandwidth being created and removed. To realize this,
* we append vnodes to a "workitem" queue. When running with a soft
* updates implementation, most pending metadata dependencies should
* not wait for more than a few seconds. Thus, mounted on block devices
* are delayed only about a half the time that file data is delayed.
* Similarly, directory updates are more critical, so are only delayed
* about a third the time that file data is delayed. Thus, there are
* SYNCER_MAXDELAY queues that are processed round-robin at a rate of
* one each second (driven off the filesystem syner process). The
* syncer_delayno variable indicates the next queue that is to be processed.
* Items that need to be processed soon are placed in this queue:
*
* syncer_workitem_pending[syncer_delayno]
*
* A delay of fifteen seconds is done by placing the request fifteen
* entries later in the queue:
*
* syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
*
*/
/*
* Add an item to the syncer work queue.
*/
void
vn_syncer_add_to_worklist(vp, delay)
struct vnode *vp;
int delay;
{
int s, slot;
s = splbio();
if (vp->v_flag & VONWORKLST) {
LIST_REMOVE(vp, v_synclist);
}
if (delay > syncer_maxdelay - 2)
delay = syncer_maxdelay - 2;
slot = (syncer_delayno + delay) & syncer_mask;
LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist);
vp->v_flag |= VONWORKLST;
splx(s);
}
static void sched_sync __P((void));
static struct proc *updateproc;
static struct kproc_desc up_kp = {
"syncer",
sched_sync,
&updateproc
};
SYSINIT_KT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
/*
* System filesystem synchronizer daemon.
*/
void
sched_sync(void)
{
struct synclist *slp;
struct vnode *vp;
long starttime;
int s;
struct proc *p = updateproc;
for (;;) {
starttime = time.tv_sec;
/*
* Push files whose dirty time has expired.
*/
s = splbio();
slp = &syncer_workitem_pending[syncer_delayno];
syncer_delayno += 1;
if (syncer_delayno == syncer_maxdelay)
syncer_delayno = 0;
splx(s);
while ((vp = LIST_FIRST(slp)) != NULL) {
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
(void) VOP_FSYNC(vp, p->p_ucred, MNT_LAZY, p);
VOP_UNLOCK(vp, 0, p);
if (LIST_FIRST(slp) == vp) {
if (LIST_FIRST(&vp->v_dirtyblkhd) == NULL &&
vp->v_type != VBLK)
panic("sched_sync: fsync failed");
/*
* Move ourselves to the back of the sync list.
*/
LIST_REMOVE(vp, v_synclist);
vn_syncer_add_to_worklist(vp, syncdelay);
}
}
/*
* Do soft update processing.
*/
if (bioops.io_sync)
(*bioops.io_sync)(NULL);
/*
* The variable rushjob allows the kernel to speed up the
* processing of the filesystem syncer process. A rushjob
* value of N tells the filesystem syncer to process the next
* N seconds worth of work on its queue ASAP. Currently rushjob
* is used by the soft update code to speed up the filesystem
* syncer process when the incore state is getting so far
* ahead of the disk that the kernel memory pool is being
* threatened with exhaustion.
*/
if (rushjob > 0) {
rushjob -= 1;
continue;
}
/*
* If it has taken us less than a second to process the
* current work, then wait. Otherwise start right over
* again. We can still lose time if any single round
* takes more than two seconds, but it does not really
* matter as we are just trying to generally pace the
* filesystem activity.
*/
if (time.tv_sec == starttime)
tsleep(&lbolt, PPAUSE, "syncer", 0);
}
}
/*
* Associate a p-buffer with a vnode.
*/
void
pbgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
#if defined(DIAGNOSTIC)
if (bp->b_vp)
panic("pbgetvp: not free");
#endif
bp->b_vp = vp;
if (vp->v_type == VBLK || vp->v_type == VCHR)
bp->b_dev = vp->v_rdev;
else
bp->b_dev = NODEV;
}
/*
* Disassociate a p-buffer from a vnode.
*/
void
pbrelvp(bp)
register struct buf *bp;
{
#if defined(DIAGNOSTIC)
if (bp->b_vp == (struct vnode *) 0)
panic("pbrelvp: NULL");
#endif
bp->b_vp = (struct vnode *) 0;
}
/*
* Reassign a buffer from one vnode to another.
* Used to assign file specific control information
* (indirect blocks) to the vnode to which they belong.
*/
void
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
struct buflists *listheadp;
int delay;
int s;
if (newvp == NULL) {
printf("reassignbuf: NULL");
return;
}
s = splbio();
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_vnbufs.le_next != NOLIST) {
bufremvn(bp);
vdrop(bp->b_vp);
}
/*
* If dirty, put on list of dirty buffers; otherwise insert onto list
* of clean buffers.
*/
if (bp->b_flags & B_DELWRI) {
struct buf *tbp;
listheadp = &newvp->v_dirtyblkhd;
if ((newvp->v_flag & VONWORKLST) == 0) {
switch (newvp->v_type) {
case VDIR:
delay = syncdelay / 3;
break;
case VBLK:
if (newvp->v_specmountpoint != NULL) {
delay = syncdelay / 2;
break;
}
/* fall through */
default:
delay = syncdelay;
}
vn_syncer_add_to_worklist(newvp, delay);
}
tbp = listheadp->lh_first;
if (!tbp || (tbp->b_lblkno > bp->b_lblkno)) {
bufinsvn(bp, listheadp);
} else {
while (tbp->b_vnbufs.le_next &&
(tbp->b_vnbufs.le_next->b_lblkno < bp->b_lblkno)) {
tbp = tbp->b_vnbufs.le_next;
}
LIST_INSERT_AFTER(tbp, bp, b_vnbufs);
}
} else {
bufinsvn(bp, &newvp->v_cleanblkhd);
if ((newvp->v_flag & VONWORKLST) &&
LIST_FIRST(&newvp->v_dirtyblkhd) == NULL) {
newvp->v_flag &= ~VONWORKLST;
LIST_REMOVE(newvp, v_synclist);
}
}
bp->b_vp = newvp;
vhold(bp->b_vp);
splx(s);
}
#ifndef DEVFS_ROOT
/*
* Create a vnode for a block device.
* Used for mounting the root file system.
*/
int
bdevvp(dev, vpp)
dev_t dev;
struct vnode **vpp;
{
register struct vnode *vp;
struct vnode *nvp;
int error;
if (dev == NODEV)
return (0);
error = getnewvnode(VT_NON, (struct mount *) 0, spec_vnodeop_p, &nvp);
if (error) {
*vpp = 0;
return (error);
}
vp = nvp;
vp->v_type = VBLK;
if ((nvp = checkalias(vp, dev, (struct mount *) 0))) {
vput(vp);
vp = nvp;
}
*vpp = vp;
return (0);
}
#endif /* !DEVFS_ROOT */
/*
* Check to see if the new vnode represents a special device
* for which we already have a vnode (either because of
* bdevvp() or because of a different vnode representing
* the same block device). If such an alias exists, deallocate
* the existing contents and return the aliased vnode. The
* caller is responsible for filling it with its new contents.
*/
struct vnode *
checkalias(nvp, nvp_rdev, mp)
register struct vnode *nvp;
dev_t nvp_rdev;
struct mount *mp;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp;
struct vnode **vpp;
if (nvp->v_type != VBLK && nvp->v_type != VCHR)
return (NULLVP);
vpp = &speclisth[SPECHASH(nvp_rdev)];
loop:
simple_lock(&spechash_slock);
for (vp = *vpp; vp; vp = vp->v_specnext) {
if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type)
continue;
/*
* Alias, but not in use, so flush it out.
*/
simple_lock(&vp->v_interlock);
if (vp->v_usecount == 0) {
simple_unlock(&spechash_slock);
vgonel(vp, p);
goto loop;
}
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) {
simple_unlock(&spechash_slock);
goto loop;
}
break;
}
if (vp == NULL || vp->v_tag != VT_NON) {
MALLOC(nvp->v_specinfo, struct specinfo *,
sizeof(struct specinfo), M_VNODE, M_WAITOK);
nvp->v_rdev = nvp_rdev;
nvp->v_hashchain = vpp;
nvp->v_specnext = *vpp;
nvp->v_specmountpoint = NULL;
simple_unlock(&spechash_slock);
*vpp = nvp;
if (vp != NULLVP) {
nvp->v_flag |= VALIASED;
vp->v_flag |= VALIASED;
vput(vp);
}
return (NULLVP);
}
simple_unlock(&spechash_slock);
VOP_UNLOCK(vp, 0, p);
simple_lock(&vp->v_interlock);
vclean(vp, 0, p);
vp->v_op = nvp->v_op;
vp->v_tag = nvp->v_tag;
nvp->v_type = VNON;
insmntque(vp, mp);
return (vp);
}
/*
* Grab a particular vnode from the free list, increment its
* reference count and lock it. The vnode lock bit is set the
* vnode is being eliminated in vgone. The process is awakened
* when the transition is completed, and an error returned to
* indicate that the vnode is no longer usable (possibly having
* been changed to a new file system type).
*/
int
vget(vp, flags, p)
register struct vnode *vp;
int flags;
struct proc *p;
{
int error;
/*
* If the vnode is in the process of being cleaned out for
* another use, we wait for the cleaning to finish and then
* return failure. Cleaning is determined by checking that
* the VXLOCK flag is set.
*/
if ((flags & LK_INTERLOCK) == 0) {
simple_lock(&vp->v_interlock);
}
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vget", 0);
return (ENOENT);
}
vp->v_usecount++;
if (VSHOULDBUSY(vp))
vbusy(vp);
if (flags & LK_TYPE_MASK) {
if ((error = vn_lock(vp, flags | LK_INTERLOCK, p)) != 0) {
/*
* must expand vrele here because we do not want
* to call VOP_INACTIVE if the reference count
* drops back to zero since it was never really
* active. We must remove it from the free list
* before sleeping so that multiple processes do
* not try to recycle it.
*/
simple_lock(&vp->v_interlock);
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
simple_unlock(&vp->v_interlock);
}
return (error);
}
simple_unlock(&vp->v_interlock);
return (0);
}
void
vref(struct vnode *vp)
{
simple_lock(&vp->v_interlock);
vp->v_usecount++;
simple_unlock(&vp->v_interlock);
}
/*
* Vnode put/release.
* If count drops to zero, call inactive routine and return to freelist.
*/
void
vrele(vp)
struct vnode *vp;
{
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if (vp == NULL)
panic("vrele: null vp");
#endif
simple_lock(&vp->v_interlock);
if (vp->v_usecount > 1) {
vp->v_usecount--;
simple_unlock(&vp->v_interlock);
return;
}
if (vp->v_usecount == 1) {
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
/*
* If we are doing a vput, the node is already locked, and we must
* call VOP_INACTIVE with the node locked. So, in the case of
* vrele, we explicitly lock the vnode before calling VOP_INACTIVE.
*/
if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, p) == 0) {
VOP_INACTIVE(vp, p);
}
} else {
#ifdef DIAGNOSTIC
vprint("vrele: negative ref count", vp);
simple_unlock(&vp->v_interlock);
#endif
panic("vrele: negative ref cnt");
}
}
void
vput(vp)
struct vnode *vp;
{
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if (vp == NULL)
panic("vput: null vp");
#endif
simple_lock(&vp->v_interlock);
if (vp->v_usecount > 1) {
vp->v_usecount--;
VOP_UNLOCK(vp, LK_INTERLOCK, p);
return;
}
if (vp->v_usecount == 1) {
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
/*
* If we are doing a vput, the node is already locked, and we must
* call VOP_INACTIVE with the node locked. So, in the case of
* vrele, we explicitly lock the vnode before calling VOP_INACTIVE.
*/
simple_unlock(&vp->v_interlock);
VOP_INACTIVE(vp, p);
} else {
#ifdef DIAGNOSTIC
vprint("vput: negative ref count", vp);
#endif
panic("vput: negative ref cnt");
}
}
/*
* Somebody doesn't want the vnode recycled.
*/
void
vhold(vp)
register struct vnode *vp;
{
simple_lock(&vp->v_interlock);
vp->v_holdcnt++;
if (VSHOULDBUSY(vp))
vbusy(vp);
simple_unlock(&vp->v_interlock);
}
/*
* One less who cares about this vnode.
*/
void
vdrop(vp)
register struct vnode *vp;
{
simple_lock(&vp->v_interlock);
if (vp->v_holdcnt <= 0)
panic("vdrop: holdcnt");
vp->v_holdcnt--;
if (VSHOULDFREE(vp))
vfree(vp);
simple_unlock(&vp->v_interlock);
}
/*
* Remove any vnodes in the vnode table belonging to mount point mp.
*
* If MNT_NOFORCE is specified, there should not be any active ones,
* return error if any are found (nb: this is a user error, not a
* system error). If MNT_FORCE is specified, detach any active vnodes
* that are found.
*/
#ifdef DIAGNOSTIC
static int busyprt = 0; /* print out busy vnodes */
SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
#endif
int
vflush(mp, skipvp, flags)
struct mount *mp;
struct vnode *skipvp;
int flags;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp, *nvp;
int busy = 0;
simple_lock(&mntvnode_slock);
loop:
for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) {
/*
* Make sure this vnode wasn't reclaimed in getnewvnode().
* Start over if it has (it won't be on the list anymore).
*/
if (vp->v_mount != mp)
goto loop;
nvp = vp->v_mntvnodes.le_next;
/*
* Skip over a selected vnode.
*/
if (vp == skipvp)
continue;
simple_lock(&vp->v_interlock);
/*
* Skip over a vnodes marked VSYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
simple_unlock(&vp->v_interlock);
continue;
}
/*
* If WRITECLOSE is set, only flush out regular file vnodes
* open for writing.
*/
if ((flags & WRITECLOSE) &&
(vp->v_writecount == 0 || vp->v_type != VREG)) {
simple_unlock(&vp->v_interlock);
continue;
}
/*
* With v_usecount == 0, all we need to do is clear out the
* vnode data structures and we are done.
*/
if (vp->v_usecount == 0) {
simple_unlock(&mntvnode_slock);
vgonel(vp, p);
simple_lock(&mntvnode_slock);
continue;
}
/*
* If FORCECLOSE is set, forcibly close the vnode. For block
* or character devices, revert to an anonymous device. For
* all other files, just kill them.
*/
if (flags & FORCECLOSE) {
simple_unlock(&mntvnode_slock);
if (vp->v_type != VBLK && vp->v_type != VCHR) {
vgonel(vp, p);
} else {
vclean(vp, 0, p);
vp->v_op = spec_vnodeop_p;
insmntque(vp, (struct mount *) 0);
}
simple_lock(&mntvnode_slock);
continue;
}
#ifdef DIAGNOSTIC
if (busyprt)
vprint("vflush: busy vnode", vp);
#endif
simple_unlock(&vp->v_interlock);
busy++;
}
simple_unlock(&mntvnode_slock);
if (busy)
return (EBUSY);
return (0);
}
/*
* Disassociate the underlying file system from a vnode.
*/
static void
vclean(vp, flags, p)
struct vnode *vp;
int flags;
struct proc *p;
{
int active;
vm_object_t obj;
/*
* Check to see if the vnode is in use. If so we have to reference it
* before we clean it out so that its count cannot fall to zero and
* generate a race against ourselves to recycle it.
*/
if ((active = vp->v_usecount))
vp->v_usecount++;
/*
* Prevent the vnode from being recycled or brought into use while we
* clean it out.
*/
if (vp->v_flag & VXLOCK)
panic("vclean: deadlock");
vp->v_flag |= VXLOCK;
/*
* Even if the count is zero, the VOP_INACTIVE routine may still
* have the object locked while it cleans it out. The VOP_LOCK
* ensures that the VOP_INACTIVE routine is done with its work.
* For active vnodes, it ensures that no other activity can
* occur while the underlying object is being cleaned out.
*/
VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, p);
/*
* Clean out any buffers associated with the vnode.
*/
vinvalbuf(vp, V_SAVE, NOCRED, p, 0, 0);
if (obj = vp->v_object) {
if (obj->ref_count == 0) {
/*
* This is a normal way of shutting down the object/vnode
* association.
*/
vm_object_terminate(obj);
} else {
/*
* Woe to the process that tries to page now :-).
*/
vm_pager_deallocate(obj);
}
}
/*
* If purging an active vnode, it must be closed and
* deactivated before being reclaimed. Note that the
* VOP_INACTIVE will unlock the vnode.
*/
if (active) {
if (flags & DOCLOSE)
VOP_CLOSE(vp, IO_NDELAY, NOCRED, p);
VOP_INACTIVE(vp, p);
} else {
/*
* Any other processes trying to obtain this lock must first
* wait for VXLOCK to clear, then call the new lock operation.
*/
VOP_UNLOCK(vp, 0, p);
}
/*
* Reclaim the vnode.
*/
if (VOP_RECLAIM(vp, p))
panic("vclean: cannot reclaim");
if (active)
vrele(vp);
cache_purge(vp);
if (vp->v_vnlock) {
#if 0 /* This is the only place we have LK_DRAINED in the entire kernel ??? */
#ifdef DIAGNOSTIC
if ((vp->v_vnlock->lk_flags & LK_DRAINED) == 0)
vprint("vclean: lock not drained", vp);
#endif
#endif
FREE(vp->v_vnlock, M_VNODE);
vp->v_vnlock = NULL;
}
if (VSHOULDFREE(vp))
vfree(vp);
/*
* Done with purge, notify sleepers of the grim news.
*/
vp->v_op = dead_vnodeop_p;
vn_pollgone(vp);
vp->v_tag = VT_NON;
vp->v_flag &= ~VXLOCK;
if (vp->v_flag & VXWANT) {
vp->v_flag &= ~VXWANT;
wakeup((caddr_t) vp);
}
}
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
vop_revoke(ap)
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap;
{
struct vnode *vp, *vq;
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if ((ap->a_flags & REVOKEALL) == 0)
panic("vop_revoke");
#endif
vp = ap->a_vp;
simple_lock(&vp->v_interlock);
if (vp->v_flag & VALIASED) {
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0);
return (0);
}
/*
* Ensure that vp will not be vgone'd while we
* are eliminating its aliases.
*/
vp->v_flag |= VXLOCK;
simple_unlock(&vp->v_interlock);
while (vp->v_flag & VALIASED) {
simple_lock(&spechash_slock);
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type || vp == vq)
continue;
simple_unlock(&spechash_slock);
vgone(vq);
break;
}
if (vq == NULLVP) {
simple_unlock(&spechash_slock);
}
}
/*
* Remove the lock so that vgone below will
* really eliminate the vnode after which time
* vgone will awaken any sleepers.
*/
simple_lock(&vp->v_interlock);
vp->v_flag &= ~VXLOCK;
if (vp->v_flag & VXWANT) {
vp->v_flag &= ~VXWANT;
wakeup(vp);
}
}
vgonel(vp, p);
return (0);
}
/*
* Recycle an unused vnode to the front of the free list.
* Release the passed interlock if the vnode will be recycled.
*/
int
vrecycle(vp, inter_lkp, p)
struct vnode *vp;
struct simplelock *inter_lkp;
struct proc *p;
{
simple_lock(&vp->v_interlock);
if (vp->v_usecount == 0) {
if (inter_lkp) {
simple_unlock(inter_lkp);
}
vgonel(vp, p);
return (1);
}
simple_unlock(&vp->v_interlock);
return (0);
}
/*
* Eliminate all activity associated with a vnode
* in preparation for reuse.
*/
void
vgone(vp)
register struct vnode *vp;
{
struct proc *p = curproc; /* XXX */
simple_lock(&vp->v_interlock);
vgonel(vp, p);
}
/*
* vgone, with the vp interlock held.
*/
static void
vgonel(vp, p)
struct vnode *vp;
struct proc *p;
{
int s;
struct vnode *vq;
struct vnode *vx;
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vgone", 0);
return;
}
/*
* Clean out the filesystem specific data.
*/
vclean(vp, DOCLOSE, p);
simple_lock(&vp->v_interlock);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
insmntque(vp, (struct mount *)0);
/*
* If special device, remove it from special device alias list
* if it is on one.
*/
if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_specinfo != 0) {
simple_lock(&spechash_slock);
if (*vp->v_hashchain == vp) {
*vp->v_hashchain = vp->v_specnext;
} else {
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_specnext != vp)
continue;
vq->v_specnext = vp->v_specnext;
break;
}
if (vq == NULL)
panic("missing bdev");
}
if (vp->v_flag & VALIASED) {
vx = NULL;
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type)
continue;
if (vx)
break;
vx = vq;
}
if (vx == NULL)
panic("missing alias");
if (vq == NULL)
vx->v_flag &= ~VALIASED;
vp->v_flag &= ~VALIASED;
}
simple_unlock(&spechash_slock);
FREE(vp->v_specinfo, M_VNODE);
vp->v_specinfo = NULL;
}
/*
* If it is on the freelist and not already at the head,
* move it to the head of the list. The test of the back
* pointer and the reference count of zero is because
* it will be removed from the free list by getnewvnode,
* but will not have its reference count incremented until
* after calling vgone. If the reference count were
* incremented first, vgone would (incorrectly) try to
* close the previous instance of the underlying object.
*/
if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) {
s = splbio();
simple_lock(&vnode_free_list_slock);
if (vp->v_flag & VFREE) {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
} else if (vp->v_flag & VTBFREE) {
TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist);
vp->v_flag &= ~VTBFREE;
freevnodes++;
} else
freevnodes++;
vp->v_flag |= VFREE;
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
simple_unlock(&vnode_free_list_slock);
splx(s);
}
vp->v_type = VBAD;
simple_unlock(&vp->v_interlock);
}
/*
* Lookup a vnode by device number.
*/
int
vfinddev(dev, type, vpp)
dev_t dev;
enum vtype type;
struct vnode **vpp;
{
register struct vnode *vp;
int rc = 0;
simple_lock(&spechash_slock);
for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
if (dev != vp->v_rdev || type != vp->v_type)
continue;
*vpp = vp;
rc = 1;
break;
}
simple_unlock(&spechash_slock);
return (rc);
}
/*
* Calculate the total number of references to a special device.
*/
int
vcount(vp)
register struct vnode *vp;
{
struct vnode *vq, *vnext;
int count;
loop:
if ((vp->v_flag & VALIASED) == 0)
return (vp->v_usecount);
simple_lock(&spechash_slock);
for (count = 0, vq = *vp->v_hashchain; vq; vq = vnext) {
vnext = vq->v_specnext;
if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type)
continue;
/*
* Alias, but not in use, so flush it out.
*/
if (vq->v_usecount == 0 && vq != vp) {
simple_unlock(&spechash_slock);
vgone(vq);
goto loop;
}
count += vq->v_usecount;
}
simple_unlock(&spechash_slock);
return (count);
}
/*
* Print out a description of a vnode.
*/
static char *typename[] =
{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
void
vprint(label, vp)
char *label;
register struct vnode *vp;
{
char buf[64];
if (label != NULL)
printf("%s: %x: ", label, vp);
else
printf("%x: ", vp);
printf("type %s, usecount %d, writecount %d, refcount %ld,",
typename[vp->v_type], vp->v_usecount, vp->v_writecount,
vp->v_holdcnt);
buf[0] = '\0';
if (vp->v_flag & VROOT)
strcat(buf, "|VROOT");
if (vp->v_flag & VTEXT)
strcat(buf, "|VTEXT");
if (vp->v_flag & VSYSTEM)
strcat(buf, "|VSYSTEM");
if (vp->v_flag & VXLOCK)
strcat(buf, "|VXLOCK");
if (vp->v_flag & VXWANT)
strcat(buf, "|VXWANT");
if (vp->v_flag & VBWAIT)
strcat(buf, "|VBWAIT");
if (vp->v_flag & VALIASED)
strcat(buf, "|VALIASED");
if (vp->v_flag & VDOOMED)
strcat(buf, "|VDOOMED");
if (vp->v_flag & VFREE)
strcat(buf, "|VFREE");
if (vp->v_flag & VOBJBUF)
strcat(buf, "|VOBJBUF");
if (buf[0] != '\0')
printf(" flags (%s)", &buf[1]);
if (vp->v_data == NULL) {
printf("\n");
} else {
printf("\n\t");
VOP_PRINT(vp);
}
}
#ifdef DDB
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
static void
printlockedvnodes()
{
struct proc *p = curproc; /* XXX */
struct mount *mp, *nmp;
struct vnode *vp;
printf("Locked vnodes\n");
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
nmp = mp->mnt_list.cqe_next;
continue;
}
for (vp = mp->mnt_vnodelist.lh_first;
vp != NULL;
vp = vp->v_mntvnodes.le_next) {
if (VOP_ISLOCKED(vp))
vprint((char *)0, vp);
}
simple_lock(&mountlist_slock);
nmp = mp->mnt_list.cqe_next;
vfs_unbusy(mp, p);
}
simple_unlock(&mountlist_slock);
}
#endif
/*
* Top level filesystem related information gathering.
*/
static int sysctl_ovfs_conf __P(SYSCTL_HANDLER_ARGS);
static int
vfs_sysctl SYSCTL_HANDLER_ARGS
{
int *name = (int *)arg1 - 1; /* XXX */
u_int namelen = arg2 + 1; /* XXX */
struct vfsconf *vfsp;
#ifndef NO_COMPAT_PRELITE2
/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
if (namelen == 1)
return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
#endif
#ifdef notyet
/* all sysctl names at this level are at least name and field */
if (namelen < 2)
return (ENOTDIR); /* overloaded */
if (name[0] != VFS_GENERIC) {
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[0])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
oldp, oldlenp, newp, newlen, p));
}
#endif
switch (name[1]) {
case VFS_MAXTYPENUM:
if (namelen != 2)
return (ENOTDIR);
return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
case VFS_CONF:
if (namelen != 3)
return (ENOTDIR); /* overloaded */
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[2])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
}
return (EOPNOTSUPP);
}
SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
"Generic filesystem");
#ifndef NO_COMPAT_PRELITE2
static int
sysctl_ovfs_conf SYSCTL_HANDLER_ARGS
{
int error;
struct vfsconf *vfsp;
struct ovfsconf ovfs;
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
strcpy(ovfs.vfc_name, vfsp->vfc_name);
ovfs.vfc_index = vfsp->vfc_typenum;
ovfs.vfc_refcount = vfsp->vfc_refcount;
ovfs.vfc_flags = vfsp->vfc_flags;
error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
if (error)
return error;
}
return 0;
}
#endif /* !NO_COMPAT_PRELITE2 */
static volatile int kinfo_vdebug = 1;
#if 0
#define KINFO_VNODESLOP 10
/*
* Dump vnode list (via sysctl).
* Copyout address of vnode followed by vnode.
*/
/* ARGSUSED */
static int
sysctl_vnode SYSCTL_HANDLER_ARGS
{
struct proc *p = curproc; /* XXX */
struct mount *mp, *nmp;
struct vnode *nvp, *vp;
int error;
#define VPTRSZ sizeof (struct vnode *)
#define VNODESZ sizeof (struct vnode)
req->lock = 0;
if (!req->oldptr) /* Make an estimate */
return (SYSCTL_OUT(req, 0,
(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
nmp = mp->mnt_list.cqe_next;
continue;
}
again:
simple_lock(&mntvnode_slock);
for (vp = mp->mnt_vnodelist.lh_first;
vp != NULL;
vp = nvp) {
/*
* Check that the vp is still associated with
* this filesystem. RACE: could have been
* recycled onto the same filesystem.
*/
if (vp->v_mount != mp) {
simple_unlock(&mntvnode_slock);
if (kinfo_vdebug)
printf("kinfo: vp changed\n");
goto again;
}
nvp = vp->v_mntvnodes.le_next;
simple_unlock(&mntvnode_slock);
if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
(error = SYSCTL_OUT(req, vp, VNODESZ)))
return (error);
simple_lock(&mntvnode_slock);
}
simple_unlock(&mntvnode_slock);
simple_lock(&mountlist_slock);
nmp = mp->mnt_list.cqe_next;
vfs_unbusy(mp, p);
}
simple_unlock(&mountlist_slock);
return (0);
}
#endif
/*
* XXX
* Exporting the vnode list on large systems causes them to crash.
* Exporting the vnode list on medium systems causes sysctl to coredump.
*/
#if 0
SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
0, 0, sysctl_vnode, "S,vnode", "");
#endif
/*
* Check to see if a filesystem is mounted on a block device.
*/
int
vfs_mountedon(vp)
struct vnode *vp;
{
struct vnode *vq;
int error = 0;
if (vp->v_specmountpoint != NULL)
return (EBUSY);
if (vp->v_flag & VALIASED) {
simple_lock(&spechash_slock);
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type)
continue;
if (vq->v_specmountpoint != NULL) {
error = EBUSY;
break;
}
}
simple_unlock(&spechash_slock);
}
return (error);
}
/*
* Unmount all filesystems. The list is traversed in reverse order
* of mounting to avoid dependencies.
*/
void
vfs_unmountall()
{
struct mount *mp, *nmp;
struct proc *p = initproc; /* XXX XXX should this be proc0? */
int error;
/*
* Since this only runs when rebooting, it is not interlocked.
*/
for (mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_prev;
error = dounmount(mp, MNT_FORCE, p);
if (error) {
printf("unmount of %s failed (",
mp->mnt_stat.f_mntonname);
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
}
}
}
/*
* Build hash lists of net addresses and hang them off the mount point.
* Called by ufs_mount() to set up the lists of export addresses.
*/
static int
vfs_hang_addrlist(mp, nep, argp)
struct mount *mp;
struct netexport *nep;
struct export_args *argp;
{
register struct netcred *np;
register struct radix_node_head *rnh;
register int i;
struct radix_node *rn;
struct sockaddr *saddr, *smask = 0;
struct domain *dom;
int error;
if (argp->ex_addrlen == 0) {
if (mp->mnt_flag & MNT_DEFEXPORTED)
return (EPERM);
np = &nep->ne_defexported;
np->netc_exflags = argp->ex_flags;
np->netc_anon = argp->ex_anon;
np->netc_anon.cr_ref = 1;
mp->mnt_flag |= MNT_DEFEXPORTED;
return (0);
}
i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK);
bzero((caddr_t) np, i);
saddr = (struct sockaddr *) (np + 1);
if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
goto out;
if (saddr->sa_len > argp->ex_addrlen)
saddr->sa_len = argp->ex_addrlen;
if (argp->ex_masklen) {
smask = (struct sockaddr *) ((caddr_t) saddr + argp->ex_addrlen);
error = copyin(argp->ex_mask, (caddr_t) smask, argp->ex_masklen);
if (error)
goto out;
if (smask->sa_len > argp->ex_masklen)
smask->sa_len = argp->ex_masklen;
}
i = saddr->sa_family;
if ((rnh = nep->ne_rtable[i]) == 0) {
/*
* Seems silly to initialize every AF when most are not used,
* do so on demand here
*/
for (dom = domains; dom; dom = dom->dom_next)
if (dom->dom_family == i && dom->dom_rtattach) {
dom->dom_rtattach((void **) &nep->ne_rtable[i],
dom->dom_rtoffset);
break;
}
if ((rnh = nep->ne_rtable[i]) == 0) {
error = ENOBUFS;
goto out;
}
}
rn = (*rnh->rnh_addaddr) ((caddr_t) saddr, (caddr_t) smask, rnh,
np->netc_rnodes);
if (rn == 0 || np != (struct netcred *) rn) { /* already exists */
error = EPERM;
goto out;
}
np->netc_exflags = argp->ex_flags;
np->netc_anon = argp->ex_anon;
np->netc_anon.cr_ref = 1;
return (0);
out:
free(np, M_NETADDR);
return (error);
}
/* ARGSUSED */
static int
vfs_free_netcred(rn, w)
struct radix_node *rn;
void *w;
{
register struct radix_node_head *rnh = (struct radix_node_head *) w;
(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
free((caddr_t) rn, M_NETADDR);
return (0);
}
/*
* Free the net address hash lists that are hanging off the mount points.
*/
static void
vfs_free_addrlist(nep)
struct netexport *nep;
{
register int i;
register struct radix_node_head *rnh;
for (i = 0; i <= AF_MAX; i++)
if ((rnh = nep->ne_rtable[i])) {
(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
(caddr_t) rnh);
free((caddr_t) rnh, M_RTABLE);
nep->ne_rtable[i] = 0;
}
}
int
vfs_export(mp, nep, argp)
struct mount *mp;
struct netexport *nep;
struct export_args *argp;
{
int error;
if (argp->ex_flags & MNT_DELEXPORT) {
if (mp->mnt_flag & MNT_EXPUBLIC) {
vfs_setpublicfs(NULL, NULL, NULL);
mp->mnt_flag &= ~MNT_EXPUBLIC;
}
vfs_free_addrlist(nep);
mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
}
if (argp->ex_flags & MNT_EXPORTED) {
if (argp->ex_flags & MNT_EXPUBLIC) {
if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
return (error);
mp->mnt_flag |= MNT_EXPUBLIC;
}
if ((error = vfs_hang_addrlist(mp, nep, argp)))
return (error);
mp->mnt_flag |= MNT_EXPORTED;
}
return (0);
}
/*
* Set the publicly exported filesystem (WebNFS). Currently, only
* one public filesystem is possible in the spec (RFC 2054 and 2055)
*/
int
vfs_setpublicfs(mp, nep, argp)
struct mount *mp;
struct netexport *nep;
struct export_args *argp;
{
int error;
struct vnode *rvp;
char *cp;
/*
* mp == NULL -> invalidate the current info, the FS is
* no longer exported. May be called from either vfs_export
* or unmount, so check if it hasn't already been done.
*/
if (mp == NULL) {
if (nfs_pub.np_valid) {
nfs_pub.np_valid = 0;
if (nfs_pub.np_index != NULL) {
FREE(nfs_pub.np_index, M_TEMP);
nfs_pub.np_index = NULL;
}
}
return (0);
}
/*
* Only one allowed at a time.
*/
if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
return (EBUSY);
/*
* Get real filehandle for root of exported FS.
*/
bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
if ((error = VFS_ROOT(mp, &rvp)))
return (error);
if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
return (error);
vput(rvp);
/*
* If an indexfile was specified, pull it in.
*/
if (argp->ex_indexfile != NULL) {
MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
M_WAITOK);
error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
MAXNAMLEN, (size_t *)0);
if (!error) {
/*
* Check for illegal filenames.
*/
for (cp = nfs_pub.np_index; *cp; cp++) {
if (*cp == '/') {
error = EINVAL;
break;
}
}
}
if (error) {
FREE(nfs_pub.np_index, M_TEMP);
return (error);
}
}
nfs_pub.np_mount = mp;
nfs_pub.np_valid = 1;
return (0);
}
struct netcred *
vfs_export_lookup(mp, nep, nam)
register struct mount *mp;
struct netexport *nep;
struct sockaddr *nam;
{
register struct netcred *np;
register struct radix_node_head *rnh;
struct sockaddr *saddr;
np = NULL;
if (mp->mnt_flag & MNT_EXPORTED) {
/*
* Lookup in the export list first.
*/
if (nam != NULL) {
saddr = nam;
rnh = nep->ne_rtable[saddr->sa_family];
if (rnh != NULL) {
np = (struct netcred *)
(*rnh->rnh_matchaddr)((caddr_t)saddr,
rnh);
if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
np = NULL;
}
}
/*
* If no address match, use the default if it exists.
*/
if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
np = &nep->ne_defexported;
}
return (np);
}
/*
* perform msync on all vnodes under a mount point
* the mount point must be locked.
*/
void
vfs_msync(struct mount *mp, int flags) {
struct vnode *vp, *nvp;
int anyio, tries;
tries = 5;
loop:
anyio = 0;
for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
nvp = vp->v_mntvnodes.le_next;
if (vp->v_mount != mp) {
goto loop;
}
if ((vp->v_flag & VXLOCK) ||
(VOP_ISLOCKED(vp) && (flags != MNT_WAIT))) {
continue;
}
simple_lock(&vp->v_interlock);
if (vp->v_object &&
(vp->v_object->flags & OBJ_MIGHTBEDIRTY)) {
if (!vget(vp,
LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curproc)) {
if (vp->v_object) {
vm_object_page_clean(vp->v_object, 0, 0, TRUE);
anyio = 1;
}
vput(vp);
}
} else {
simple_unlock(&vp->v_interlock);
}
}
if (anyio && (--tries > 0))
goto loop;
}
/*
* Create the VM object needed for VMIO and mmap support. This
* is done for all VREG files in the system. Some filesystems might
* afford the additional metadata buffering capability of the
* VMIO code by making the device node be VMIO mode also.
*
* If !waslocked, must be called with interlock.
*/
int
vfs_object_create(vp, p, cred, waslocked)
struct vnode *vp;
struct proc *p;
struct ucred *cred;
int waslocked;
{
struct vattr vat;
vm_object_t object;
int error = 0;
if ((vp->v_type != VREG) && (vp->v_type != VBLK)) {
if (!waslocked)
simple_unlock(&vp->v_interlock);
return 0;
}
if (!waslocked)
vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY, p);
retry:
if ((object = vp->v_object) == NULL) {
if (vp->v_type == VREG) {
if ((error = VOP_GETATTR(vp, &vat, cred, p)) != 0)
goto retn;
object = vnode_pager_alloc(vp,
OFF_TO_IDX(round_page(vat.va_size)), 0, 0);
} else if (major(vp->v_rdev) < nblkdev) {
/*
* This simply allocates the biggest object possible
* for a VBLK vnode. This should be fixed, but doesn't
* cause any problems (yet).
*/
object = vnode_pager_alloc(vp, INT_MAX, 0, 0);
}
object->ref_count--;
vp->v_usecount--;
} else {
if (object->flags & OBJ_DEAD) {
VOP_UNLOCK(vp, 0, p);
tsleep(object, PVM, "vodead", 0);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
goto retry;
}
}
if (vp->v_object) {
vp->v_flag |= VOBJBUF;
}
retn:
if (!waslocked) {
simple_lock(&vp->v_interlock);
VOP_UNLOCK(vp, LK_INTERLOCK, p);
}
return error;
}
static void
vfree(vp)
struct vnode *vp;
{
int s;
s = splbio();
simple_lock(&vnode_free_list_slock);
if (vp->v_flag & VTBFREE) {
TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist);
vp->v_flag &= ~VTBFREE;
}
if (vp->v_flag & VAGE) {
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
} else {
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
freevnodes++;
simple_unlock(&vnode_free_list_slock);
vp->v_flag &= ~VAGE;
vp->v_flag |= VFREE;
splx(s);
}
void
vbusy(vp)
struct vnode *vp;
{
int s;
s = splbio();
simple_lock(&vnode_free_list_slock);
if (vp->v_flag & VTBFREE) {
TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist);
vp->v_flag &= ~VTBFREE;
} else {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
freevnodes--;
}
simple_unlock(&vnode_free_list_slock);
vp->v_flag &= ~(VFREE|VAGE);
splx(s);
}
/*
* Record a process's interest in events which might happen to
* a vnode. Because poll uses the historic select-style interface
* internally, this routine serves as both the ``check for any
* pending events'' and the ``record my interest in future events''
* functions. (These are done together, while the lock is held,
* to avoid race conditions.)
*/
int
vn_pollrecord(vp, p, events)
struct vnode *vp;
struct proc *p;
short events;
{
simple_lock(&vp->v_pollinfo.vpi_lock);
if (vp->v_pollinfo.vpi_revents & events) {
/*
* This leaves events we are not interested
* in available for the other process which
* which presumably had requested them
* (otherwise they would never have been
* recorded).
*/
events &= vp->v_pollinfo.vpi_revents;
vp->v_pollinfo.vpi_revents &= ~events;
simple_unlock(&vp->v_pollinfo.vpi_lock);
return events;
}
vp->v_pollinfo.vpi_events |= events;
selrecord(p, &vp->v_pollinfo.vpi_selinfo);
simple_unlock(&vp->v_pollinfo.vpi_lock);
return 0;
}
/*
* Note the occurrence of an event. If the VN_POLLEVENT macro is used,
* it is possible for us to miss an event due to race conditions, but
* that condition is expected to be rare, so for the moment it is the
* preferred interface.
*/
void
vn_pollevent(vp, events)
struct vnode *vp;
short events;
{
simple_lock(&vp->v_pollinfo.vpi_lock);
if (vp->v_pollinfo.vpi_events & events) {
/*
* We clear vpi_events so that we don't
* call selwakeup() twice if two events are
* posted before the polling process(es) is
* awakened. This also ensures that we take at
* most one selwakeup() if the polling process
* is no longer interested. However, it does
* mean that only one event can be noticed at
* a time. (Perhaps we should only clear those
* event bits which we note?) XXX
*/
vp->v_pollinfo.vpi_events = 0; /* &= ~events ??? */
vp->v_pollinfo.vpi_revents |= events;
selwakeup(&vp->v_pollinfo.vpi_selinfo);
}
simple_unlock(&vp->v_pollinfo.vpi_lock);
}
/*
* Wake up anyone polling on vp because it is being revoked.
* This depends on dead_poll() returning POLLHUP for correct
* behavior.
*/
void
vn_pollgone(vp)
struct vnode *vp;
{
simple_lock(&vp->v_pollinfo.vpi_lock);
if (vp->v_pollinfo.vpi_events) {
vp->v_pollinfo.vpi_events = 0;
selwakeup(&vp->v_pollinfo.vpi_selinfo);
}
simple_unlock(&vp->v_pollinfo.vpi_lock);
}
/*
* Routine to create and manage a filesystem syncer vnode.
*/
#define sync_close ((int (*) __P((struct vop_close_args *)))nullop)
int sync_fsync __P((struct vop_fsync_args *));
int sync_inactive __P((struct vop_inactive_args *));
int sync_reclaim __P((struct vop_reclaim_args *));
#define sync_lock ((int (*) __P((struct vop_lock_args *)))vop_nolock)
#define sync_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock)
int sync_print __P((struct vop_print_args *));
#define sync_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked)
vop_t **sync_vnodeop_p;
struct vnodeopv_entry_desc sync_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_eopnotsupp },
{ &vop_close_desc, (vop_t *) sync_close }, /* close */
{ &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */
{ &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */
{ &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */
{ &vop_lock_desc, (vop_t *) sync_lock }, /* lock */
{ &vop_unlock_desc, (vop_t *) sync_unlock }, /* unlock */
{ &vop_print_desc, (vop_t *) sync_print }, /* print */
{ &vop_islocked_desc, (vop_t *) sync_islocked }, /* islocked */
{ NULL, NULL }
};
struct vnodeopv_desc sync_vnodeop_opv_desc =
{ &sync_vnodeop_p, sync_vnodeop_entries };
VNODEOP_SET(sync_vnodeop_opv_desc);
/*
* Create a new filesystem syncer vnode for the specified mount point.
*/
int
vfs_allocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
static long start, incr, next;
int error;
/* Allocate a new vnode */
if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) {
mp->mnt_syncer = NULL;
return (error);
}
vp->v_type = VNON;
/*
* Place the vnode onto the syncer worklist. We attempt to
* scatter them about on the list so that they will go off
* at evenly distributed times even if all the filesystems
* are mounted at once.
*/
next += incr;
if (next == 0 || next > syncer_maxdelay) {
start /= 2;
incr /= 2;
if (start == 0) {
start = syncer_maxdelay / 2;
incr = syncer_maxdelay;
}
next = start;
}
vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0);
mp->mnt_syncer = vp;
return (0);
}
/*
* Do a lazy sync of the filesystem.
*/
int
sync_fsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct proc *a_p;
} */ *ap;
{
struct vnode *syncvp = ap->a_vp;
struct mount *mp = syncvp->v_mount;
struct proc *p = ap->a_p;
int asyncflag;
/*
* We only need to do something if this is a lazy evaluation.
*/
if (ap->a_waitfor != MNT_LAZY)
return (0);
/*
* Move ourselves to the back of the sync list.
*/
vn_syncer_add_to_worklist(syncvp, syncdelay);
/*
* Walk the list of vnodes pushing all that are dirty and
* not already on the sync list.
*/
simple_lock(&mountlist_slock);
if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_slock, p) != 0)
return (0);
asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
VFS_SYNC(mp, MNT_LAZY, ap->a_cred, p);
if (asyncflag)
mp->mnt_flag |= MNT_ASYNC;
vfs_unbusy(mp, p);
return (0);
}
/*
* The syncer vnode is no referenced.
*/
int
sync_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap;
{
vgone(ap->a_vp);
return (0);
}
/*
* The syncer vnode is no longer needed and is being decommissioned.
*/
int
sync_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
vp->v_mount->mnt_syncer = NULL;
if (vp->v_flag & VONWORKLST) {
LIST_REMOVE(vp, v_synclist);
vp->v_flag &= ~VONWORKLST;
}
return (0);
}
/*
* Print out a syncer vnode.
*/
int
sync_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
printf("syncer vnode");
if (vp->v_vnlock != NULL)
lockmgr_printinfo(vp->v_vnlock);
printf("\n");
return (0);
}
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