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NetBSD/sys/kern/vfs_subr.c

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/*
* Copyright (c) 1989 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.
*
* from: @(#)vfs_subr.c 7.60 (Berkeley) 6/21/91
* $Id: vfs_subr.c,v 1.29 1994/05/17 04:22:04 cgd Exp $
*/
/*
* External virtual filesystem routines
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h> /* XXX */
#include <sys/namei.h>
#include <sys/ucred.h>
#include <sys/buf.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <vm/vm.h>
#include <sys/sysctl.h>
/*
* Flag to allow forcible unmounting.
*/
int doforce = 1;
int prtactive; /* 1 => print out reclaim of active vnodes */
void vprint __P((char *label, struct vnode *vp));
/*
* 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; \
}
TAILQ_HEAD(freelst, vnode) vnode_free_list; /* vnode free list */
struct mntlist mountlist; /* mounted filesystem list */
/*
* Remove a mount point from the list of mounted filesystems.
* Unmount of the root is illegal.
*/
void
vfs_remove(mp)
register struct mount *mp;
{
if (mp == rootfs)
panic("vfs_remove: unmounting root");
TAILQ_REMOVE(&mountlist, mp, mnt_list);
mp->mnt_vnodecovered->v_mountedhere = (struct mount *)0;
vfs_unlock(mp);
}
/*
* Lock a filesystem.
* Used to prevent access to it while mounting and unmounting.
*/
vfs_lock(mp)
register struct mount *mp;
{
while(mp->mnt_flag & MNT_MLOCK) {
mp->mnt_flag |= MNT_MWAIT;
tsleep((caddr_t)mp, PVFS, "vfslock", 0);
}
mp->mnt_flag |= MNT_MLOCK;
return (0);
}
/*
* Unlock a locked filesystem.
* Panic if filesystem is not locked.
*/
void
vfs_unlock(mp)
register struct mount *mp;
{
if ((mp->mnt_flag & MNT_MLOCK) == 0)
panic("vfs_unlock: not locked");
mp->mnt_flag &= ~MNT_MLOCK;
if (mp->mnt_flag & MNT_MWAIT) {
mp->mnt_flag &= ~MNT_MWAIT;
wakeup((caddr_t)mp);
}
}
/*
* Mark a mount point as busy.
* Used to synchronize access and to delay unmounting.
*/
vfs_busy(mp)
register struct mount *mp;
{
while(mp->mnt_flag & MNT_MPBUSY) {
mp->mnt_flag |= MNT_MPWANT;
tsleep((caddr_t)&mp->mnt_flag, PVFS, "vfsbusy", 0);
}
if (mp->mnt_flag & MNT_UNMOUNT)
return (1);
mp->mnt_flag |= MNT_MPBUSY;
return (0);
}
/*
* Free a busy filesystem.
* Panic if filesystem is not busy.
*/
vfs_unbusy(mp)
register struct mount *mp;
{
if ((mp->mnt_flag & MNT_MPBUSY) == 0)
panic("vfs_unbusy: not busy");
mp->mnt_flag &= ~MNT_MPBUSY;
if (mp->mnt_flag & MNT_MPWANT) {
mp->mnt_flag &= ~MNT_MPWANT;
wakeup((caddr_t)&mp->mnt_flag);
}
}
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
getvfs(fsid)
fsid_t *fsid;
{
register struct mount *mp;
for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next)
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1])
return (mp);
return ((struct mount *)0);
}
/*
* Check to see if a filesystem is mounted on a block device.
*/
mountedon(vp)
register struct vnode *vp;
{
register struct vnode *vq;
if (vp->v_specflags & SI_MOUNTEDON)
return (EBUSY);
if (vp->v_flag & VALIASED) {
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_specflags & SI_MOUNTEDON)
return (EBUSY);
}
}
return (0);
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid =
vap->va_fsid = vap->va_fileid = vap->va_size =
vap->va_blocksize = vap->va_rdev = vap->va_bytes =
vap->va_atime.ts_sec = vap->va_atime.ts_nsec =
vap->va_mtime.ts_sec = vap->va_mtime.ts_nsec =
vap->va_ctime.ts_sec = vap->va_ctime.ts_nsec =
vap->va_flags = vap->va_gen = VNOVAL;
vap->va_vaflags = 0;
}
/*
* Routines having to do with the management of the vnode table.
*/
extern struct vnodeops dead_vnodeops, spec_vnodeops;
extern void vclean();
long numvnodes;
struct vattr va_null;
/*
* Initialize the vnode structures and initialize each file system type.
*/
void
vfsinit()
{
int i;
/* initialize the vnode management data structures */
TAILQ_INIT(&vnode_free_list);
TAILQ_INIT(&mountlist);
/*
* Initialize the vnode name cache
*/
nchinit();
/*
* Initialize each file system type.
*/
vattr_null(&va_null);
for (i = 0; i < nvfssw; i++) {
if (vfssw[i] == NULL)
continue;
(*(vfssw[i]->vfs_init))();
}
}
/*
* Get a new unique fsid
*/
void
getnewfsid(mp, mtype)
struct mount *mp;
int mtype;
{
static u_short xxxfs_mntid;
fsid_t tfsid;
mp->mnt_stat.f_fsid.val[0] = makedev(nblkdev + 11, 0); /* XXX */
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 (rootfs) {
while (getvfs(&tfsid)) {
tfsid.val[0]++;
xxxfs_mntid++;
}
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
}
/*
* make a 'unique' number from a mount type name
*/
long
makefstype(type)
char *type;
{
long rv;
for (rv = 0; *type; type++) {
rv <<= 2;
rv ^= *type;
}
return rv;
}
/*
* Return the next vnode from the free list.
*/
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
struct vnodeops *vops;
struct vnode **vpp;
{
register struct vnode *vp, *vq;
if ((vnode_free_list.tqh_first == NULL &&
numvnodes < 2 * desiredvnodes) ||
numvnodes < desiredvnodes) {
vp = (struct vnode *)malloc((u_long)sizeof *vp,
M_VNODE, M_WAITOK);
bzero((char *)vp, sizeof *vp);
numvnodes++;
} else {
if ((vp = vnode_free_list.tqh_first) == NULL) {
tablefull("vnode");
*vpp = 0;
return (ENFILE);
}
if (vp->v_usecount)
panic("free vnode isn't");
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
vp->v_freelist.tqe_prev = (struct vnode **)0xdeadb;
if (vp->v_type != VBAD)
vgone(vp);
vp->v_flag = 0;
vp->v_lastr = 0;
vp->v_socket = 0;
}
vp->v_type = VNON;
cache_purge(vp);
vp->v_tag = tag;
vp->v_op = vops;
insmntque(vp, mp);
vp->v_usecount = 1;
*vpp = vp;
return (0);
}
/*
* Move a vnode from one mount queue to another.
*/
insmntque(vp, mp)
register struct vnode *vp;
register struct mount *mp;
{
register struct vnode *vq;
/*
* 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)
return;
LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes);
}
/*
* Make sure all write-behind blocks associated
* with mount point are flushed out (from sync).
*/
mntflushbuf(mountp, flags)
struct mount *mountp;
int flags;
{
register struct vnode *vp;
if ((mountp->mnt_flag & MNT_MPBUSY) == 0)
panic("mntflushbuf: not busy");
loop:
for (vp = mountp->mnt_vnodelist.lh_first; vp;
vp = vp->v_mntvnodes.le_next) {
if (VOP_ISLOCKED(vp))
continue;
if (vget(vp, 1))
goto loop;
vflushbuf(vp, flags);
vput(vp);
if (vp->v_mount != mountp)
goto loop;
}
}
/*
* Flush all dirty buffers associated with a vnode.
*/
vflushbuf(vp, flags)
register struct vnode *vp;
int flags;
{
register struct buf *bp;
struct buf *nbp;
int s;
loop:
s = splbio();
for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;
if ((bp->b_flags & B_BUSY))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("vflushbuf: not dirty");
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
/*
* Wait for I/O associated with indirect blocks to complete,
* since there is no way to quickly wait for them below.
* NB: This is really specific to ufs, but is done here
* as it is easier and quicker.
*/
if (bp->b_vp == vp || (flags & B_SYNC) == 0)
(void) bawrite(bp);
else
(void) bwrite(bp);
goto loop;
}
splx(s);
if ((flags & B_SYNC) == 0)
return;
s = splbio();
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vflshbuf", 0);
}
splx(s);
if (vp->v_dirtyblkhd.lh_first != NULL) {
vprint("vflushbuf: dirty", vp);
goto loop;
}
}
/*
* Update outstanding I/O count and do wakeup if requested.
*/
vwakeup(bp)
register struct buf *bp;
{
register struct vnode *vp;
bp->b_dirtyoff = bp->b_dirtyend = 0;
if (vp = bp->b_vp) {
vp->v_numoutput--;
if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
if (vp->v_numoutput < 0)
panic("vwakeup: neg numoutput");
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t)&vp->v_numoutput);
}
}
}
/*
* Invalidate in core blocks belonging to closed or umounted filesystem
*
* Go through the list of vnodes associated with the file system;
* for each vnode invalidate any buffers that it holds. Normally
* this routine is preceeded by a bflush call, so that on a quiescent
* filesystem there will be no dirty buffers when we are done. Binval
* returns the count of dirty buffers when it is finished.
*/
mntinvalbuf(mountp)
struct mount *mountp;
{
register struct vnode *vp;
int dirty = 0;
if ((mountp->mnt_flag & MNT_MPBUSY) == 0)
panic("mntinvalbuf: not busy");
loop:
for (vp = mountp->mnt_vnodelist.lh_first; vp;
vp = vp->v_mntvnodes.le_next) {
if (vget(vp, 1))
goto loop;
dirty += vinvalbuf(vp, 1);
vput(vp);
if (vp->v_mount != mountp)
goto loop;
}
return (dirty);
}
/*
* Flush out and invalidate all buffers associated with a vnode.
* Called with the underlying object locked.
*/
vinvalbuf(vp, save)
register struct vnode *vp;
int save;
{
register struct buf *bp;
struct buf *nbp, *blist;
int s, dirty = 0;
for (;;) {
if (blist = vp->v_dirtyblkhd.lh_first)
/* void */;
else if (blist = vp->v_cleanblkhd.lh_first)
/* void */;
else
break;
for (bp = blist; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;
s = splbio();
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
tsleep((caddr_t)bp, PRIBIO + 1, "vinvalbuf", 0);
splx(s);
break;
}
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
if (save && (bp->b_flags & B_DELWRI)) {
dirty++;
(void) bwrite(bp);
break;
}
if (bp->b_vp != vp)
reassignbuf(bp, bp->b_vp);
else
bp->b_flags |= B_INVAL;
brelse(bp);
}
}
if (vp->v_dirtyblkhd.lh_first != NULL ||
vp->v_cleanblkhd.lh_first != NULL)
panic("vinvalbuf: flush failed");
return (dirty);
}
/*
* Associate a buffer with a vnode.
*/
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
register struct vnode *vq;
register struct buf *bq;
if (bp->b_vp)
panic("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.
*/
bufinsvn(bp, &vp->v_cleanblkhd);
}
/*
* Disassociate a buffer from a vnode.
*/
brelvp(bp)
register struct buf *bp;
{
struct buf *bq;
struct vnode *vp;
if (bp->b_vp == (struct vnode *) 0)
panic("brelvp: NULL");
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_vnbufs.le_next != NOLIST)
bufremvn(bp);
vp = bp->b_vp;
bp->b_vp = (struct vnode *) 0;
HOLDRELE(vp);
}
/*
* Reassign a buffer from one vnode to another.
* Used to assign file specific control information
* (indirect blocks) to the vnode to which they belong.
*/
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
struct buf *bq;
struct buflists *listheadp;
if (newvp == NULL)
panic("reassignbuf: NULL");
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_vnbufs.le_next != NOLIST)
bufremvn(bp);
/*
* If dirty, put on list of dirty buffers;
* otherwise insert onto list of clean buffers.
*/
if (bp->b_flags & B_DELWRI)
listheadp = &newvp->v_dirtyblkhd;
else
listheadp = &newvp->v_cleanblkhd;
bufinsvn(bp, listheadp);
}
/*
* Create a vnode for a block device.
* Used for root filesystem, argdev, and swap areas.
* Also used for memory file system special devices.
*/
bdevvp(dev, vpp)
dev_t dev;
struct vnode **vpp;
{
return(getdevvp(dev, vpp, VBLK));
}
/*
* Create a vnode for a character device.
* Used for kernfs and some console handling.
*/
cdevvp(dev, vpp)
dev_t dev;
struct vnode **vpp;
{
return(getdevvp(dev, vpp, VCHR));
}
/*
* Create a vnode for a device.
* Used by bdevvp (block device) for root file system etc.,
* and by cdevvp (character device) for console and kernfs.
*/
getdevvp(dev, vpp, type)
dev_t dev;
struct vnode **vpp;
enum vtype type;
{
register struct vnode *vp;
struct vnode *nvp;
int error;
if (dev == NODEV)
return (0);
error = getnewvnode(VT_NON, (struct mount *)0, &spec_vnodeops, &nvp);
if (error) {
*vpp = NULLVP;
return (error);
}
vp = nvp;
vp->v_type = type;
if (nvp = checkalias(vp, dev, (struct mount *)0)) {
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;
{
register struct vnode *vp;
struct vnode **vpp;
if (nvp->v_type != VBLK && nvp->v_type != VCHR)
return (NULLVP);
vpp = &speclisth[SPECHASH(nvp_rdev)];
loop:
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.
*/
if (vp->v_usecount == 0) {
vgone(vp);
goto loop;
}
if (vget(vp, 1))
goto loop;
break;
}
if (vp == NULL || vp->v_tag != VT_NON || vp->v_type != VBLK) {
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_specflags = 0;
*vpp = nvp;
if (vp != NULL) {
nvp->v_flag |= VALIASED;
vp->v_flag |= VALIASED;
vput(vp);
}
return (NULLVP);
}
VOP_UNLOCK(vp);
vclean(vp, 0);
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).
*/
vget(vp, lockflag)
register struct vnode *vp;
int lockflag;
{
register struct vnode *vq;
if ((vp->v_flag & VXLOCK) ||
(vp->v_usecount == 0 &&
vp->v_freelist.tqe_prev == (struct vnode **)0xdeadb)) {
vp->v_flag |= VXWANT;
tsleep((caddr_t)vp, PINOD, "vget", 0);
return (1);
}
if (vp->v_usecount == 0)
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
vp->v_usecount++;
if (lockflag)
VOP_LOCK(vp);
return (0);
}
/*
* Vnode reference, just increment the count
*/
void
vref(vp)
struct vnode *vp;
{
if (vp->v_usecount <= 0)
panic("vref used where vget required");
vp->v_usecount++;
}
/*
* vput(), just unlock and vrele()
*/
void
vput(vp)
register struct vnode *vp;
{
VOP_UNLOCK(vp);
vrele(vp);
}
/*
* Vnode release.
* If count drops to zero, call inactive routine and return to freelist.
*/
void
vrele(vp)
register struct vnode *vp;
{
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if (vp == NULL)
panic("vrele: null vp");
#endif
vp->v_usecount--;
if (vp->v_usecount > 0)
return;
#ifdef DIAGNOSTIC
if (vp->v_usecount != 0 || vp->v_writecount != 0) {
vprint("vrele: bad ref count", vp);
panic("vrele: ref cnt");
}
#endif
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
VOP_INACTIVE(vp, p);
}
/*
* Page or buffer structure gets a reference.
*/
vhold(vp)
register struct vnode *vp;
{
vp->v_holdcnt++;
}
/*
* Page or buffer structure frees a reference.
*/
holdrele(vp)
register struct vnode *vp;
{
if (vp->v_holdcnt <= 0)
panic("holdrele: holdcnt");
vp->v_holdcnt--;
}
/*
* 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.
*/
int busyprt = 0; /* patch to print out busy vnodes */
vflush(mp, skipvp, flags)
struct mount *mp;
struct vnode *skipvp;
int flags;
{
register struct vnode *vp, *nvp;
int busy = 0;
if ((mp->mnt_flag & MNT_MPBUSY) == 0)
panic("vflush: not busy");
loop:
for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) {
if (vp->v_mount != mp)
goto loop;
nvp = vp->v_mntvnodes.le_next;
/*
* Skip over a selected vnode.
*/
if (vp == skipvp)
continue;
/*
* Skip over a vnodes marked VSYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM))
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) {
vgone(vp);
continue;
}
/*
* For block or character devices, revert to an
* anonymous device. For all other files, just kill them.
*/
if (flags & FORCECLOSE) {
if (vp->v_type != VBLK && vp->v_type != VCHR) {
vgone(vp);
} else {
vclean(vp, 0);
vp->v_op = &spec_vnodeops;
insmntque(vp, (struct mount *)0);
}
continue;
}
if (busyprt)
vprint("vflush: busy vnode", vp);
busy++;
}
if (busy)
return (EBUSY);
return (0);
}
/*
* Disassociate the underlying file system from a vnode.
*/
void
vclean(vp, flags)
register struct vnode *vp;
int flags;
{
struct vnodeops *origops;
int active;
struct proc *p = curproc; /* XXX */
/*
* 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)
VREF(vp);
/*
* 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 buffer list is being cleaned out.
*/
VOP_LOCK(vp);
if (flags & DOCLOSE)
vinvalbuf(vp, 1);
/*
* Prevent any further operations on the vnode from
* being passed through to the old file system.
*/
origops = vp->v_op;
vp->v_op = &dead_vnodeops;
vp->v_tag = VT_NON;
/*
* If purging an active vnode, it must be unlocked, closed,
* and deactivated before being reclaimed.
*/
(*(origops->vop_unlock))(vp);
if (active) {
if (flags & DOCLOSE)
(*(origops->vop_close))(vp, IO_NDELAY, NOCRED, p);
(*(origops->vop_inactive))(vp, p);
}
/*
* Reclaim the vnode.
*/
if ((*(origops->vop_reclaim))(vp))
panic("vclean: cannot reclaim");
if (active)
vrele(vp);
/*
* Done with purge, notify sleepers in vget of the grim news.
*/
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.
*/
void
vgoneall(vp)
register struct vnode *vp;
{
register struct vnode *vq;
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;
tsleep((caddr_t)vp, PINOD, "vgoneall", 0);
return;
}
/*
* Ensure that vp will not be vgone'd while we
* are eliminating its aliases.
*/
vp->v_flag |= VXLOCK;
while (vp->v_flag & VALIASED) {
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;
vgone(vq);
break;
}
}
/*
* Remove the lock so that vgone below will
* really eliminate the vnode after which time
* vgone will awaken any sleepers.
*/
vp->v_flag &= ~VXLOCK;
}
vgone(vp);
}
/*
* Eliminate all activity associated with a vnode
* in preparation for reuse.
*/
void
vgone(vp)
register struct vnode *vp;
{
register 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;
tsleep((caddr_t)vp, PINOD, "vgone", 0);
return;
}
/*
* Clean out the filesystem specific data.
*/
vclean(vp, DOCLOSE);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL) {
LIST_REMOVE(vp, v_mntvnodes);
vp->v_mount = NULL;
}
/*
* If special device, remove it from special device alias list.
*/
if (vp->v_type == VBLK || vp->v_type == VCHR) {
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 != NULL)
break;
vx = vq;
}
if (vx == NULL)
panic("missing alias");
if (vq == NULL)
vx->v_flag &= ~VALIASED;
vp->v_flag &= ~VALIASED;
}
FREE(vp->v_specinfo, M_VNODE);
vp->v_specinfo = NULL;
}
/*
* If it is on the freelist, move it to the head of the list.
*/
if (vp->v_usecount == 0 &&
vp->v_freelist.tqe_prev != (struct vnode **)0xdeadb &&
vnode_free_list.tqh_first != vp) {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
}
vp->v_type = VBAD;
}
/*
* Lookup a vnode by device number.
*/
vfinddev(dev, type, vpp)
dev_t dev;
enum vtype type;
struct vnode **vpp;
{
register struct vnode *vp;
for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
if (dev != vp->v_rdev || type != vp->v_type)
continue;
*vpp = vp;
return (0);
}
return (1);
}
/*
* Calculate the total number of references to a special device.
*/
vcount(vp)
register struct vnode *vp;
{
register struct vnode *vq;
int count;
loop:
if ((vp->v_flag & VALIASED) == 0)
return (vp->v_usecount);
for (count = 0, vq = *vp->v_hashchain; vq; vq = 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) {
vgone(vq);
goto loop;
}
count += vq->v_usecount;
}
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: ", label);
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 (buf[0] != '\0')
printf(" flags (%s)", &buf[1]);
printf("\n\t");
VOP_PRINT(vp);
}
#ifdef DEBUG
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
printlockedvnodes()
{
register struct mount *mp;
register struct vnode *vp;
printf("Locked vnodes\n");
for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next) {
for (vp = mp->mnt_vnodelist.lh_first; vp != NULL;
vp = vp->v_mntvnodes.le_next)
if (VOP_ISLOCKED(vp))
vprint((char *)0, vp);
}
}
#endif
int kinfo_vdebug = 1;
int kinfo_vgetfailed;
#define KINFO_VNODESLOP 10
/*
* Dump vnode list (via sysctl).
* Copyout address of vnode followed by vnode.
*/
/* ARGSUSED */
sysctl_vnode(where, sizep)
char *where;
size_t *sizep;
{
register struct mount *mp, *nmp;
struct vnode *vp;
register char *bp = where, *savebp;
char *ewhere;
int error;
#define VPTRSZ sizeof (struct vnode *)
#define VNODESZ sizeof (struct vnode)
if (where == NULL) {
*sizep = (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ);
return (0);
}
ewhere = where + *sizep;
for (mp = mountlist.tqh_first; mp != NULL; mp = nmp) {
nmp = mp->mnt_list.tqe_next;
if (vfs_busy(mp))
continue;
savebp = bp;
again:
for (vp = mp->mnt_vnodelist.lh_first;
vp != NULL;
vp = vp->v_mntvnodes.le_next) {
/*
* Check that the vp is still associated with
* this filesystem. RACE: could have been
* recycled onto the same filesystem.
*/
if (vp->v_mount != mp) {
if (kinfo_vdebug)
printf("kinfo: vp changed\n");
bp = savebp;
goto again;
}
if (bp + VPTRSZ + VNODESZ > ewhere) {
*sizep = bp - where;
return (ENOMEM);
}
if ((error = copyout((caddr_t)&vp, bp, VPTRSZ)) ||
(error = copyout((caddr_t)vp, bp + VPTRSZ, VNODESZ)))
return (error);
bp += VPTRSZ + VNODESZ;
}
vfs_unbusy(mp);
}
*sizep = bp - where;
return (0);
}
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