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freebsd-dev/sys/kern/vfs_export.c
Julian Elischer 4ef2094e45 Reviewed by: Many at differnt times in differnt parts, 
including alan, john, me, luoqi, and kirk
Submitted by:	Matt Dillon <dillon@frebsd.org>

This change implements a relatively sophisticated fix to getnewbuf().
There were two problems with getnewbuf(). First, the writerecursion
can lead to a system stack overflow when you have NFS and/or VN
devices in the system. Second, the free/dirty buffer accounting was
completely broken. Not only did the nfs routines blow it trying to
manually account for the buffer state, but the accounting that was
done did not work well with the purpose of their existance: figuring
out when getnewbuf() needs to sleep.

The meat of the change is to kern/vfs_bio.c. The remaining diffs are
all minor except for NFS, which includes both the fixes for bp
interaction AND fixes for a 'biodone(): buffer already done' lockup.
Sys/buf.h also contains a chaining structure which is not used by
this patchset but is used by other patches that are coming soon.
This patch deliniated by tags PRE_MAT_GETBUF and POST_MAT_GETBUF.
(sorry for the missing T matt)
1999-03-12 02:24:58 +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 1.188 1999/02/25 05:22:29 dillon Exp $
*/
/*
* External virtual filesystem routines
*/
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/domain.h>
#include <sys/dirent.h>
#include <sys/vmmeter.h>
#include <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.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));
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,
};
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;
#ifdef ENABLE_VFS_IOOPT
SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
#endif
struct mntlist mountlist; /* mounted filesystem list */
struct simplelock mountlist_slock;
struct simplelock mntvnode_slock;
int nfs_mount_type = -1;
#ifndef NULL_SIMPLELOCKS
static struct simplelock mntid_slock;
static struct simplelock vnode_free_list_slock;
static struct simplelock spechash_slock;
#endif
struct nfs_public nfs_pub; /* publicly exported FS */
static vm_zone_t vnode_zone;
/*
* The workitem queue.
*/
#define SYNCER_MAXDELAY 32
static 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;
if (fstypename == NULL)
return (ENODEV);
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 = VNOVAL;
vap->va_nlink = VNOVAL;
vap->va_uid = VNOVAL;
vap->va_gid = VNOVAL;
vap->va_fsid = VNOVAL;
vap->va_fileid = VNOVAL;
vap->va_blocksize = VNOVAL;
vap->va_rdev = VNOVAL;
vap->va_atime.tv_sec = VNOVAL;
vap->va_atime.tv_nsec = VNOVAL;
vap->va_mtime.tv_sec = VNOVAL;
vap->va_mtime.tv_nsec = VNOVAL;
vap->va_ctime.tv_sec = VNOVAL;
vap->va_ctime.tv_nsec = VNOVAL;
vap->va_flags = VNOVAL;
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 INVARIANTS
{
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++;
}
TAILQ_INIT(&vp->v_cleanblkhd);
TAILQ_INIT(&vp->v_dirtyblkhd);
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);
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) {
s = splbio();
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
error = tsleep((caddr_t)&vp->v_numoutput,
slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo);
if (error) {
splx(s);
return (error);
}
}
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
splx(s);
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)) != 0)
return (error);
s = splbio();
if (vp->v_numoutput > 0 ||
!TAILQ_EMPTY(&vp->v_dirtyblkhd))
panic("vinvalbuf: dirty bufs");
}
splx(s);
}
s = splbio();
for (;;) {
blist = TAILQ_FIRST(&vp->v_cleanblkhd);
if (!blist)
blist = TAILQ_FIRST(&vp->v_dirtyblkhd);
if (!blist)
break;
for (bp = blist; bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
error = tsleep((caddr_t) bp,
slpflag | (PRIBIO + 4), "vinvalbuf",
slptimeo);
if (error) {
splx(s);
return (error);
}
break;
}
/*
* 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. Note that vfs_bio_awrite expects
* buffers to reside on a queue, while VOP_BWRITE and
* brelse do not.
*/
if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
(flags & V_SAVE)) {
if (bp->b_vp == vp) {
if (bp->b_flags & B_CLUSTEROK) {
vfs_bio_awrite(bp);
} else {
bremfree(bp);
bp->b_flags |= (B_BUSY | B_ASYNC);
VOP_BWRITE(bp);
}
} else {
bremfree(bp);
bp->b_flags |= B_BUSY;
(void) VOP_BWRITE(bp);
}
break;
}
bremfree(bp);
bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF | B_BUSY);
bp->b_flags &= ~B_ASYNC;
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) {
vm_object_page_remove(object, 0, 0,
(flags & V_SAVE) ? TRUE : FALSE);
}
simple_unlock(&vp->v_interlock);
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd))
panic("vinvalbuf: flush failed");
return (0);
}
/*
* Truncate a file's buffer and pages to a specified length. This
* is in lieu of the old vinvalbuf mechanism, which performed unneeded
* sync activity.
*/
int
vtruncbuf(vp, cred, p, length, blksize)
register struct vnode *vp;
struct ucred *cred;
struct proc *p;
off_t length;
int blksize;
{
register struct buf *bp;
struct buf *nbp;
int s, anyfreed;
int trunclbn;
/*
* Round up to the *next* lbn.
*/
trunclbn = (length + blksize - 1) / blksize;
s = splbio();
restart:
anyfreed = 1;
for (;anyfreed;) {
anyfreed = 0;
for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (bp->b_lblkno >= trunclbn) {
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep(bp, PRIBIO + 4, "vtrb1", 0);
goto restart;
} else {
bremfree(bp);
bp->b_flags |= (B_BUSY | B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
}
if (nbp && (((nbp->b_xflags & B_VNCLEAN) == 0)||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI))) {
goto restart;
}
}
}
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (bp->b_lblkno >= trunclbn) {
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep(bp, PRIBIO + 4, "vtrb2", 0);
goto restart;
} else {
bremfree(bp);
bp->b_flags |= (B_BUSY | B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
}
if (nbp && (((nbp->b_xflags & B_VNDIRTY) == 0)||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI) == 0)) {
goto restart;
}
}
}
}
if (length > 0) {
restartsync:
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) {
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep(bp, PRIBIO, "vtrb3", 0);
} else {
bremfree(bp);
bp->b_flags |= B_BUSY;
if (bp->b_vp == vp) {
bp->b_flags |= B_ASYNC;
} else {
bp->b_flags &= ~B_ASYNC;
}
VOP_BWRITE(bp);
}
goto restartsync;
}
}
}
while (vp->v_numoutput > 0) {
vp->v_flag |= VBWAIT;
tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0);
}
splx(s);
vnode_pager_setsize(vp, length);
return (0);
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
int s;
KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
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();
bp->b_xflags |= B_VNCLEAN;
bp->b_xflags &= ~B_VNDIRTY;
TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs);
splx(s);
}
/*
* Disassociate a buffer from a vnode.
*/
void
brelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
struct buflists *listheadp;
int s;
KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
/*
* Delete from old vnode list, if on one.
*/
vp = bp->b_vp;
s = splbio();
if (bp->b_xflags & (B_VNDIRTY|B_VNCLEAN)) {
if (bp->b_xflags & B_VNDIRTY)
listheadp = &vp->v_dirtyblkhd;
else
listheadp = &vp->v_cleanblkhd;
TAILQ_REMOVE(listheadp, bp, b_vnbufs);
bp->b_xflags &= ~(B_VNDIRTY|B_VNCLEAN);
}
if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
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.
*/
static void
vn_syncer_add_to_worklist(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);
}
struct proc *updateproc;
static void sched_sync __P((void));
static const 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_second;
/*
* Push files whose dirty time has expired. Be careful
* of interrupt race on slp queue.
*/
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) {
if (VOP_ISLOCKED(vp) == 0) {
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
(void) VOP_FSYNC(vp, p->p_ucred, MNT_LAZY, p);
VOP_UNLOCK(vp, 0, p);
}
s = splbio();
if (LIST_FIRST(slp) == vp) {
/*
* Note: v_tag VT_VFS vps can remain on the
* worklist too with no dirty blocks, but
* since sync_fsync() moves it to a different
* slot we are safe.
*/
if (TAILQ_EMPTY(&vp->v_dirtyblkhd) &&
vp->v_type != VBLK)
panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag);
/*
* Put us back on the worklist. The worklist
* routine will remove us from our current
* position and then add us back in at a later
* position.
*/
vn_syncer_add_to_worklist(vp, syncdelay);
}
splx(s);
}
/*
* 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_second == starttime)
tsleep(&lbolt, PPAUSE, "syncer", 0);
}
}
/*
* Associate a p-buffer with a vnode.
*
* Also sets B_PAGING flag to indicate that vnode is not fully associated
* with the buffer. i.e. the bp has not been linked into the vnode or
* ref-counted.
*/
void
pbgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
KASSERT(bp->b_vp == NULL, ("pbgetvp: not free"));
bp->b_vp = vp;
bp->b_flags |= B_PAGING;
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;
{
KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
#if !defined(MAX_PERF)
/* XXX REMOVE ME */
if (bp->b_vnbufs.tqe_next != NULL) {
panic(
"relpbuf(): b_vp was probably reassignbuf()d %p %x",
bp,
(int)bp->b_flags
);
}
#endif
bp->b_vp = (struct vnode *) 0;
bp->b_flags &= ~B_PAGING;
}
void
pbreassignbuf(bp, newvp)
struct buf *bp;
struct vnode *newvp;
{
#if !defined(MAX_PERF)
if ((bp->b_flags & B_PAGING) == 0) {
panic(
"pbreassignbuf() on non phys bp %p",
bp
);
}
#endif
bp->b_vp = newvp;
}
/*
* 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;
}
#if !defined(MAX_PERF)
/*
* B_PAGING flagged buffers cannot be reassigned because their vp
* is not fully linked in.
*/
if (bp->b_flags & B_PAGING)
panic("cannot reassign paging buffer");
#endif
s = splbio();
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_xflags & (B_VNDIRTY|B_VNCLEAN)) {
if (bp->b_xflags & B_VNDIRTY)
listheadp = &bp->b_vp->v_dirtyblkhd;
else
listheadp = &bp->b_vp->v_cleanblkhd;
TAILQ_REMOVE(listheadp, bp, b_vnbufs);
bp->b_xflags &= ~(B_VNDIRTY|B_VNCLEAN);
if (bp->b_vp != newvp) {
vdrop(bp->b_vp);
bp->b_vp = NULL; /* for clarification */
}
}
/*
* 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);
}
bp->b_xflags |= B_VNDIRTY;
tbp = TAILQ_FIRST(listheadp);
if (tbp == NULL ||
(bp->b_lblkno >= 0 && tbp->b_lblkno > bp->b_lblkno)) {
TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs);
} else {
if (bp->b_lblkno >= 0) {
struct buf *ttbp;
while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) &&
(ttbp->b_lblkno < bp->b_lblkno)) {
tbp = ttbp;
}
TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
} else {
TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs);
}
}
} else {
bp->b_xflags |= B_VNCLEAN;
TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs);
if ((newvp->v_flag & VONWORKLST) &&
TAILQ_EMPTY(&newvp->v_dirtyblkhd)) {
newvp->v_flag &= ~VONWORKLST;
LIST_REMOVE(newvp, v_synclist);
}
}
if (bp->b_vp != newvp) {
bp->b_vp = newvp;
vhold(bp->b_vp);
}
splx(s);
}
/*
* 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;
/* XXX 255 is for mfs. */
if (dev == NODEV || (major(dev) != 255 && (major(dev) >= nblkdev ||
bdevsw[major(dev)] == NULL))) {
*vpp = NULLVP;
return (ENXIO);
}
error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp);
if (error) {
*vpp = NULLVP;
return (error);
}
vp = nvp;
vp->v_type = VBLK;
if ((nvp = checkalias(vp, dev, (struct mount *)0)) != NULL) {
vput(vp);
vp = nvp;
}
*vpp = vp;
return (0);
}
/*
* 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;
int rmaj = major(nvp_rdev);
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.
* Only alias active device nodes.
* Not sure why we don't re-use this like we do below.
*/
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)) {
/*
* It dissappeared, and we may have slept.
* Restart from the beginning
*/
simple_unlock(&spechash_slock);
goto loop;
}
break;
}
/*
* It would be a lot clearer what is going on here if
* this had been expressed as:
* if ( vp && (vp->v_tag == VT_NULL))
* and the clauses had been swapped.
*/
if (vp == NULL || vp->v_tag != VT_NON) {
struct specinfo *sinfo;
/*
* Put the new vnode into the hash chain.
* and if there was an alias, connect them.
*/
MALLOC(sinfo, struct specinfo *,
sizeof(struct specinfo), M_VNODE, M_WAITOK);
bzero(sinfo, sizeof(struct specinfo));
nvp->v_specinfo = sinfo;
sinfo->si_rdev = nvp_rdev;
sinfo->si_hashchain = vpp;
sinfo->si_specnext = *vpp;
sinfo->si_bsize_phys = DEV_BSIZE;
sinfo->si_bsize_best = BLKDEV_IOSIZE;
sinfo->si_bsize_max = MAXBSIZE;
/*
* Ask the device to fix up specinfo. Typically the
* si_bsize_* parameters may need fixing up.
*/
if (nvp->v_type == VBLK && rmaj < nblkdev) {
if (bdevsw[rmaj] && bdevsw[rmaj]->d_parms)
(*bdevsw[rmaj]->d_parms)(nvp_rdev, sinfo, DPARM_GET);
} else if (nvp->v_type == VCHR && rmaj < nchrdev) {
if (cdevsw[rmaj] && cdevsw[rmaj]->d_parms)
(*cdevsw[rmaj]->d_parms)(nvp_rdev, sinfo, DPARM_GET);
}
simple_unlock(&spechash_slock);
*vpp = nvp;
if (vp != NULLVP) {
nvp->v_flag |= VALIASED;
vp->v_flag |= VALIASED;
vput(vp);
}
return (NULLVP);
}
/*
* if ( vp && (vp->v_tag == VT_NULL))
* We have a vnode alias, but it is a trashed.
* Make it look like it's newley allocated. (by getnewvnode())
* The caller should use this instead.
*/
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 */
KASSERT(vp != NULL, ("vrele: null vp"));
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 */
KASSERT(vp != NULL, ("vput: null vp"));
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;
{
int s;
s = splbio();
vp->v_holdcnt++;
if (VSHOULDBUSY(vp))
vbusy(vp);
splx(s);
}
/*
* One less who cares about this vnode.
*/
void
vdrop(vp)
register struct vnode *vp;
{
int s;
s = splbio();
if (vp->v_holdcnt <= 0)
panic("vdrop: holdcnt");
vp->v_holdcnt--;
if (VSHOULDFREE(vp))
vfree(vp);
splx(s);
}
/*
* 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) != NULL) {
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, FNONBLOCK, 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 */
KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke"));
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[96];
if (label != NULL)
printf("%s: %p: ", label, (void *)vp);
else
printf("%p: ", (void *)vp);
printf("type %s, usecount %d, writecount %d, refcount %d,",
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
#include <ddb/ddb.h>
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
{
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;
#if 1 || defined(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");
#if 1 || defined(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 /* 1 || COMPAT_PRELITE2 */
#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);
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;
int error;
if (curproc != NULL)
p = curproc;
else
p = initproc; /* XXX XXX should this be proc0? */
/*
* 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;
struct vm_object *obj;
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) /* XXX: what if MNT_WAIT? */
continue;
if (flags != MNT_WAIT) {
obj = vp->v_object;
if (obj == NULL || (obj->flags & OBJ_MIGHTBEDIRTY) == 0)
continue;
if (VOP_ISLOCKED(vp))
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, flags == MNT_WAIT ? OBJPC_SYNC : 0);
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.
*
* vp must be locked when vfs_object_create is called.
*/
int
vfs_object_create(vp, p, cred)
struct vnode *vp;
struct proc *p;
struct ucred *cred;
{
struct vattr vat;
vm_object_t object;
int error = 0;
if ((vp->v_type != VREG) && (vp->v_type != VBLK))
return 0;
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, vat.va_size, 0, 0);
} else if (major(vp->v_rdev) < nblkdev &&
bdevsw[major(vp->v_rdev)] != NULL) {
/*
* 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, IDX_TO_OFF(INT_MAX), 0, 0);
} else {
goto retn;
}
/*
* Dereference the reference we just created. This assumes
* that the object is associated with the vp.
*/
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;
}
}
KASSERT(vp->v_object != NULL, ("vfs_object_create: NULL object"));
vp->v_flag |= VOBJBUF;
retn:
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)
static int sync_fsync __P((struct vop_fsync_args *));
static int sync_inactive __P((struct vop_inactive_args *));
static 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)
static int sync_print __P((struct vop_print_args *));
#define sync_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked)
static vop_t **sync_vnodeop_p;
static 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 }
};
static 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.
*/
static 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) {
simple_unlock(&mountlist_slock);
return (0);
}
asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
vfs_msync(mp, MNT_NOWAIT);
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.
*/
static 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.
*
* Modifications to the worklist must be protected at splbio().
*/
static int
sync_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
int s;
s = splbio();
vp->v_mount->mnt_syncer = NULL;
if (vp->v_flag & VONWORKLST) {
LIST_REMOVE(vp, v_synclist);
vp->v_flag &= ~VONWORKLST;
}
splx(s);
return (0);
}
/*
* Print out a syncer vnode.
*/
static 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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