d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
b430a4f0ed
freebsd-skq/sys/kern/vfs_export.c
Bruce Evans b83ddf9c86 Restored writability of kern.maxvnodes. It was broken a year ago in 
rev.1.29 of kern_sysctl.c.

Should be in 2.2.
1996-11-12 09:24:31 +00:00

1661 lines
37 KiB
C
Raw Blame History

/*
* 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 8.13 (Berkeley) 4/18/94
* $Id: vfs_subr.c,v 1.64 1996/10/28 11:34:57 phk Exp $
*/
/*
* External virtual filesystem routines
*/
#include "opt_ddb.h"
#include "opt_devfs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/namei.h>
#include <sys/ucred.h>
#include <sys/buf.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/domain.h>
#include <sys/mbuf.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
#include <sys/sysctl.h>
#include <miscfs/specfs/specdev.h>
#ifdef DDB
extern void printlockedvnodes __P((void));
#endif
extern void vclean __P((struct vnode *vp, int flags));
extern void vfs_unmountroot __P((struct mount *rootfs));
enum vtype iftovt_tab[16] = {
VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
};
int vttoif_tab[9] = {
0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
S_IFSOCK, S_IFIFO, S_IFMT,
};
/*
* Insq/Remq for the vnode usage lists.
*/
#define bufinsvn(bp, dp) LIST_INSERT_HEAD(dp, bp, b_vnbufs)
#define bufremvn(bp) { \
LIST_REMOVE(bp, b_vnbufs); \
(bp)->b_vnbufs.le_next = NOLIST; \
}
TAILQ_HEAD(freelst, vnode) vnode_free_list; /* vnode free list */
static u_long freevnodes = 0;
struct mntlist mountlist; /* mounted filesystem list */
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 + vm_object_cache_max + extravnodes;
TAILQ_INIT(&vnode_free_list);
CIRCLEQ_INIT(&mountlist);
}
/*
* Lock a filesystem.
* Used to prevent access to it while mounting and unmounting.
*/
int
vfs_lock(mp)
register struct mount *mp;
{
while (mp->mnt_flag & MNT_MLOCK) {
mp->mnt_flag |= MNT_MWAIT;
(void) tsleep((caddr_t) mp, PVFS, "vfslck", 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.
*/
int
vfs_busy(mp)
register struct mount *mp;
{
while (mp->mnt_flag & MNT_MPBUSY) {
mp->mnt_flag |= MNT_MPWANT;
(void) tsleep((caddr_t) &mp->mnt_flag, PVFS, "vfsbsy", 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.
*/
void
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);
}
}
void
vfs_unmountroot(struct mount *rootfs)
{
struct mount *mp = rootfs;
int error;
if (vfs_busy(mp)) {
printf("failed to unmount root\n");
return;
}
mp->mnt_flag |= MNT_UNMOUNT;
if ((error = vfs_lock(mp))) {
printf("lock of root filesystem failed (%d)\n", error);
return;
}
vnode_pager_umount(mp); /* release cached vnodes */
cache_purgevfs(mp); /* remove cache entries for this file sys */
if ((error = VFS_SYNC(mp, MNT_WAIT, initproc->p_ucred, initproc)))
printf("sync of root filesystem failed (%d)\n", error);
if ((error = VFS_UNMOUNT(mp, MNT_FORCE, initproc))) {
printf("unmount of root filesystem failed (");
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
}
mp->mnt_flag &= ~MNT_UNMOUNT;
vfs_unbusy(mp);
}
/*
* Unmount all filesystems. Should only be called by halt().
*/
void
vfs_unmountall()
{
struct mount *mp, *nmp, *rootfs = NULL;
int error;
/* unmount all but rootfs */
for (mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_prev;
if (mp->mnt_flag & MNT_ROOTFS) {
rootfs = mp;
continue;
}
error = dounmount(mp, MNT_FORCE, initproc);
if (error) {
printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
}
}
/* and finally... */
if (rootfs) {
vfs_unmountroot(rootfs);
} else {
printf("no root filesystem\n");
}
}
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
getvfs(fsid)
fsid_t *fsid;
{
register struct mount *mp;
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])
return (mp);
}
return ((struct mount *) 0);
}
/*
* 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 + 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 (getvfs(&tfsid)) {
tfsid.val[0]++;
xxxfs_mntid++;
}
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
vap->va_size = VNOVAL;
vap->va_bytes = VNOVAL;
vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid =
vap->va_fsid = vap->va_fileid =
vap->va_blocksize = vap->va_rdev =
vap->va_atime.tv_sec = vap->va_atime.tv_nsec =
vap->va_mtime.tv_sec = vap->va_mtime.tv_nsec =
vap->va_ctime.tv_sec = vap->va_ctime.tv_nsec =
vap->va_flags = vap->va_gen = VNOVAL;
vap->va_vaflags = 0;
}
/*
* Routines having to do with the management of the vnode table.
*/
extern vop_t **dead_vnodeop_p;
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
vop_t **vops;
struct vnode **vpp;
{
register struct vnode *vp;
retry:
vp = vnode_free_list.tqh_first;
/*
* we allocate a new vnode if
* 1. we don't have any free
* Pretty obvious, we actually used to panic, but that
* is a silly thing to do.
* 2. we havn't filled our pool yet
* We don't want to trash the incore (VM-)vnodecache.
* 3. if less that 1/4th of our vnodes are free.
* We don't want to trash the namei cache either.
*/
if (freevnodes < (numvnodes >> 2) ||
numvnodes < desiredvnodes ||
vp == NULL) {
vp = (struct vnode *) malloc((u_long) sizeof *vp,
M_VNODE, M_WAITOK);
bzero((char *) vp, sizeof *vp);
numvnodes++;
} else {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
if (vp->v_usage > 0) {
--vp->v_usage;
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
goto retry;
}
freevnodes--;
if (vp->v_usecount)
panic("free vnode isn't");
/* see comment on why 0xdeadb is set at end of vgone (below) */
vp->v_freelist.tqe_prev = (struct vnode **) 0xdeadb;
vp->v_lease = NULL;
if (vp->v_type != VBAD)
vgone(vp);
#ifdef DIAGNOSTIC
{
int s;
if (vp->v_data)
panic("cleaned vnode isn't");
s = splbio();
if (vp->v_numoutput)
panic("Clean vnode has pending I/O's");
splx(s);
}
#endif
vp->v_flag = 0;
vp->v_lastr = 0;
vp->v_ralen = 0;
vp->v_maxra = 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_usage = 0;
}
vp->v_type = VNON;
cache_purge(vp);
vp->v_tag = tag;
vp->v_op = vops;
insmntque(vp, mp);
*vpp = vp;
vp->v_usecount = 1;
vp->v_data = 0;
return (0);
}
/*
* Move a vnode from one mount queue to another.
*/
void
insmntque(vp, mp)
register struct vnode *vp;
register struct mount *mp;
{
/*
* 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);
}
/*
* 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) {
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)))
return (error);
if (vp->v_dirtyblkhd.lh_first != NULL)
panic("vinvalbuf: dirty bufs");
}
s = splbio();
for (;;) {
if ((blist = vp->v_cleanblkhd.lh_first) && (flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist && (blist = vp->v_dirtyblkhd.lh_first) &&
(flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist)
break;
for (bp = blist; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;
if ((flags & V_SAVEMETA) && bp->b_lblkno < 0)
continue;
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
error = tsleep((caddr_t) bp,
slpflag | (PRIBIO + 1), "vinvalbuf",
slptimeo);
splx(s);
if (error)
return (error);
break;
}
bremfree(bp);
bp->b_flags |= B_BUSY;
/*
* XXX Since there are no node locks for NFS, I
* believe there is a slight chance that a delayed
* write will occur while sleeping just above, so
* check for it.
*/
if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) {
(void) VOP_BWRITE(bp);
break;
}
bp->b_flags |= (B_INVAL|B_NOCACHE|B_RELBUF);
brelse(bp);
}
}
splx(s);
s = splbio();
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.
*/
object = vp->v_object;
if (object != NULL) {
vm_object_page_remove(object, 0, object->size,
(flags & V_SAVE) ? TRUE : FALSE);
}
if (!(flags & V_SAVEMETA) &&
(vp->v_dirtyblkhd.lh_first || vp->v_cleanblkhd.lh_first))
panic("vinvalbuf: flush failed");
return (0);
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
int s;
if (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.
*/
s = splbio();
bufinsvn(bp, &vp->v_cleanblkhd);
splx(s);
}
/*
* Disassociate a buffer from a vnode.
*/
void
brelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
int s;
if (bp->b_vp == (struct vnode *) 0)
panic("brelvp: NULL");
/*
* Delete from old vnode list, if on one.
*/
s = splbio();
if (bp->b_vnbufs.le_next != NOLIST)
bufremvn(bp);
splx(s);
vp = bp->b_vp;
bp->b_vp = (struct vnode *) 0;
HOLDRELE(vp);
}
/*
* Associate a p-buffer with a vnode.
*/
void
pbgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
if (bp->b_vp)
panic("pbgetvp: 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;
}
/*
* Disassociate a p-buffer from a vnode.
*/
void
pbrelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
if (bp->b_vp == (struct vnode *) 0)
panic("brelvp: NULL");
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.
*/
void
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
int s;
if (newvp == NULL) {
printf("reassignbuf: NULL");
return;
}
s = splbio();
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_vnbufs.le_next != NOLIST)
bufremvn(bp);
/*
* If dirty, put on list of dirty buffers; otherwise insert onto list
* of clean buffers.
*/
if (bp->b_flags & B_DELWRI) {
struct buf *tbp;
tbp = newvp->v_dirtyblkhd.lh_first;
if (!tbp || (tbp->b_lblkno > bp->b_lblkno)) {
bufinsvn(bp, &newvp->v_dirtyblkhd);
} else {
while (tbp->b_vnbufs.le_next &&
(tbp->b_vnbufs.le_next->b_lblkno < bp->b_lblkno)) {
tbp = tbp->b_vnbufs.le_next;
}
LIST_INSERT_AFTER(tbp, bp, b_vnbufs);
}
} else {
bufinsvn(bp, &newvp->v_cleanblkhd);
}
splx(s);
}
#ifndef DEVFS_ROOT
/*
* Create a vnode for a block device.
* Used for root filesystem, argdev, and swap areas.
* Also used for memory file system special devices.
*/
int
bdevvp(dev, vpp)
dev_t dev;
struct vnode **vpp;
{
register struct vnode *vp;
struct vnode *nvp;
int error;
if (dev == NODEV)
return (0);
error = getnewvnode(VT_NON, (struct mount *) 0, spec_vnodeop_p, &nvp);
if (error) {
*vpp = 0;
return (error);
}
vp = nvp;
vp->v_type = VBLK;
if ((nvp = checkalias(vp, dev, (struct mount *) 0))) {
vput(vp);
vp = nvp;
}
*vpp = vp;
return (0);
}
#endif /* !DEVFS_ROOT */
/*
* Check to see if the new vnode represents a special device
* for which we already have a vnode (either because of
* bdevvp() or because of a different vnode representing
* the same block device). If such an alias exists, deallocate
* the existing contents and return the aliased vnode. The
* caller is responsible for filling it with its new contents.
*/
struct vnode *
checkalias(nvp, nvp_rdev, mp)
register struct vnode *nvp;
dev_t nvp_rdev;
struct mount *mp;
{
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) {
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).
*/
int
vget(vp, lockflag)
register struct vnode *vp;
int lockflag;
{
/*
* 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 either by checking that the VXLOCK flag is
* set, or that the use count is zero with the back pointer set to
* show that it has been removed from the free list by getnewvnode.
* The VXLOCK flag may not have been set yet because vclean is blocked
* in the VOP_LOCK call waiting for the VOP_INACTIVE to complete.
*/
if ((vp->v_flag & VXLOCK) ||
(vp->v_usecount == 0 &&
vp->v_freelist.tqe_prev == (struct vnode **) 0xdeadb)) {
vp->v_flag |= VXWANT;
(void) tsleep((caddr_t) vp, PINOD, "vget", 0);
return (1);
}
if (vp->v_usecount == 0) {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
freevnodes--;
}
vp->v_usecount++;
/*
* Create the VM object, if needed
*/
if ((vp->v_type == VREG) &&
((vp->v_object == NULL) ||
(vp->v_object->flags & OBJ_VFS_REF) == 0)) {
vfs_object_create(vp, curproc, curproc->p_ucred, 0);
}
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++;
if ((vp->v_type == VREG) &&
((vp->v_object == NULL) ||
((vp->v_object->flags & OBJ_VFS_REF) == 0)) ) {
/*
* We need to lock to VP during the time that
* the object is created. This is necessary to
* keep the system from re-entrantly doing it
* multiple times.
*/
vfs_object_create(vp, curproc, curproc->p_ucred, 0);
}
}
/*
* 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;
{
#ifdef DIAGNOSTIC
if (vp == NULL)
panic("vrele: null vp");
#endif
vp->v_usecount--;
if ((vp->v_usecount == 1) &&
vp->v_object &&
(vp->v_object->flags & OBJ_VFS_REF)) {
vp->v_object->flags &= ~OBJ_VFS_REF;
vm_object_deallocate(vp->v_object);
return;
}
if (vp->v_usecount > 0)
return;
if (vp->v_usecount < 0) {
#ifdef DIAGNOSTIC
vprint("vrele: negative ref count", vp);
#endif
panic("vrele: negative reference cnt");
}
if (vp->v_flag & VAGE) {
if(vp->v_tag != VT_TFS)
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
vp->v_flag &= ~VAGE;
vp->v_usage = 0;
} else {
if(vp->v_tag != VT_TFS)
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
freevnodes++;
VOP_INACTIVE(vp);
}
#ifdef DIAGNOSTIC
/*
* Page or buffer structure gets a reference.
*/
void
vhold(vp)
register struct vnode *vp;
{
vp->v_holdcnt++;
}
/*
* Page or buffer structure frees a reference.
*/
void
holdrele(vp)
register struct vnode *vp;
{
if (vp->v_holdcnt <= 0)
panic("holdrele: holdcnt");
vp->v_holdcnt--;
}
#endif /* DIAGNOSTIC */
/*
* 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, 1, busyprt, CTLFLAG_RW, &busyprt, 0, "");
#endif
int
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) {
/*
* 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;
/*
* Skip over a vnodes marked VSYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM))
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))
continue;
if (vp->v_object && (vp->v_object->flags & OBJ_VFS_REF)) {
vm_object_reference(vp->v_object);
pager_cache(vp->v_object, FALSE);
vp->v_object->flags &= ~OBJ_VFS_REF;
vm_object_deallocate(vp->v_object);
}
/*
* 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;
}
/*
* 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) {
if (vp->v_type != VBLK && vp->v_type != VCHR) {
vgone(vp);
} else {
vclean(vp, 0);
vp->v_op = spec_vnodeop_p;
insmntque(vp, (struct mount *) 0);
}
continue;
}
#ifdef DIAGNOSTIC
if (busyprt)
vprint("vflush: busy vnode", vp);
#endif
busy++;
}
if (busy)
return (EBUSY);
return (0);
}
/*
* Disassociate the underlying file system from a vnode.
*/
void
vclean(struct vnode *vp, int flags)
{
int active;
/*
* 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);
/*
* 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);
/*
* 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;
/*
* Clean out any buffers associated with the vnode.
*/
if (flags & DOCLOSE)
vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
/*
* Any other processes trying to obtain this lock must first wait for
* VXLOCK to clear, then call the new lock operation.
*/
VOP_UNLOCK(vp);
/*
* If purging an active vnode, it must be closed and deactivated
* before being reclaimed.
*/
if (active) {
if (flags & DOCLOSE)
VOP_CLOSE(vp, FNONBLOCK, NOCRED, NULL);
VOP_INACTIVE(vp);
}
/*
* Reclaim the vnode.
*/
if (VOP_RECLAIM(vp))
panic("vclean: cannot reclaim");
if (active)
vrele(vp);
/*
* Done with purge, notify sleepers of the grim news.
*/
vp->v_op = dead_vnodeop_p;
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.
*/
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;
(void) tsleep((caddr_t) vp, PINOD, "vgall", 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;
(void) tsleep((caddr_t) vp, PINOD, "vgone", 0);
return;
}
if (vp->v_object) {
vp->v_object->flags |= OBJ_VNODE_GONE;
}
/*
* 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)
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 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. So, the back pointer is
* explicitly set to `0xdeadb' in getnewvnode after removing it from
* the freelist to ensure that we do not try to move it here.
*/
if (vp->v_usecount == 0 &&
vp->v_freelist.tqe_prev != (struct vnode **) 0xdeadb &&
vnode_free_list.tqh_first != vp) {
if(vp->v_tag != VT_TFS) {
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.
*/
int
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 (1);
}
return (0);
}
/*
* Calculate the total number of references to a special device.
*/
int
vcount(vp)
register struct vnode *vp;
{
register struct vnode *vq, *vnext;
int count;
loop:
if ((vp->v_flag & VALIASED) == 0)
return (vp->v_usecount);
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) {
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 %ld,",
typename[vp->v_type], vp->v_usecount, vp->v_writecount,
vp->v_holdcnt);
buf[0] = '\0';
if (vp->v_flag & VROOT)
strcat(buf, "|VROOT");
if (vp->v_flag & VTEXT)
strcat(buf, "|VTEXT");
if (vp->v_flag & VSYSTEM)
strcat(buf, "|VSYSTEM");
if (vp->v_flag & VXLOCK)
strcat(buf, "|VXLOCK");
if (vp->v_flag & VXWANT)
strcat(buf, "|VXWANT");
if (vp->v_flag & VBWAIT)
strcat(buf, "|VBWAIT");
if (vp->v_flag & VALIASED)
strcat(buf, "|VALIASED");
if (buf[0] != '\0')
printf(" flags (%s)", &buf[1]);
if (vp->v_data == NULL) {
printf("\n");
} else {
printf("\n\t");
VOP_PRINT(vp);
}
}
#ifdef DDB
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
void
printlockedvnodes(void)
{
register struct mount *mp;
register struct vnode *vp;
printf("Locked vnodes\n");
for (mp = mountlist.cqh_first; mp != (void *)&mountlist;
mp = mp->mnt_list.cqe_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 */
static int
sysctl_vnode SYSCTL_HANDLER_ARGS
{
register struct mount *mp, *nmp;
struct vnode *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)));
for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_next;
if (vfs_busy(mp))
continue;
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");
goto again;
}
if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
(error = SYSCTL_OUT(req, vp, VNODESZ))) {
vfs_unbusy(mp);
return (error);
}
}
vfs_unbusy(mp);
}
return (0);
}
SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
0, 0, sysctl_vnode, "S,vnode", "");
/*
* Check to see if a filesystem is mounted on a block device.
*/
int
vfs_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);
}
/*
* 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(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_addr, (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(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(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) {
vfs_free_addrlist(nep);
mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
}
if (argp->ex_flags & MNT_EXPORTED) {
if ((error = vfs_hang_addrlist(mp, nep, argp)))
return (error);
mp->mnt_flag |= MNT_EXPORTED;
}
return (0);
}
struct netcred *
vfs_export_lookup(mp, nep, nam)
register struct mount *mp;
struct netexport *nep;
struct mbuf *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 = mtod(nam, struct sockaddr *);
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;
loop:
for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
if (vp->v_mount != mp)
goto loop;
nvp = vp->v_mntvnodes.le_next;
if (VOP_ISLOCKED(vp) && (flags != MNT_WAIT))
continue;
if (vp->v_object &&
(vp->v_object->flags & OBJ_MIGHTBEDIRTY)) {
vm_object_page_clean(vp->v_object, 0, 0, TRUE, TRUE);
}
}
}
/*
* 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.
*/
int
vfs_object_create(vp, p, cred, waslocked)
struct vnode *vp;
struct proc *p;
struct ucred *cred;
int waslocked;
{
struct vattr vat;
vm_object_t object;
int error = 0;
retry:
if ((object = vp->v_object) == NULL) {
if (vp->v_type == VREG) {
if ((error = VOP_GETATTR(vp, &vat, cred, p)) != 0)
goto retn;
(void) vnode_pager_alloc(vp,
OFF_TO_IDX(round_page(vat.va_size)), 0, 0);
} else {
/*
* This simply allocates the biggest object possible
* for a VBLK vnode. This should be fixed, but doesn't
* cause any problems (yet).
*/
(void) vnode_pager_alloc(vp, INT_MAX, 0, 0);
}
vp->v_object->flags |= OBJ_VFS_REF;
} else {
if (object->flags & OBJ_DEAD) {
if (waslocked)
VOP_UNLOCK(vp);
tsleep(object, PVM, "vodead", 0);
if (waslocked)
VOP_LOCK(vp);
goto retry;
}
if ((object->flags & OBJ_VFS_REF) == 0) {
object->flags |= OBJ_VFS_REF;
vm_object_reference(object);
}
}
if (vp->v_object)
vp->v_flag |= VVMIO;
retn:
return error;
}
Reference in New Issue View Git Blame Copy Permalink