Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
44079e2f16
NetBSD/sys/kern/vfs_subr.c
cgd 21bbd49bf2 in vfs_shutdown(), print "syncing disks... " before dropping to spl0(), 
so that if the drop to spl0() causes another panic (e.g. because there's
still some fatal hardware interrupt that's pending) we'll know that we
dropped IPL to sync the disks.
1997-06-07 17:27:57 +00:00

1712 lines
39 KiB
C
Raw Blame History

/* $NetBSD: vfs_subr.c,v 1.70 1997/06/07 17:27:57 cgd Exp $ */
/*
* Copyright (c) 1997 Jason R. Thorpe. All rights reserved.
* 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
*/
/*
* External virtual filesystem routines
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <sys/fcntl.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 <sys/syscallargs.h>
#include <sys/device.h>
#include <vm/vm.h>
#include <sys/sysctl.h>
#include <miscfs/specfs/specdev.h>
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,
};
int doforce = 1; /* 1 => permit forcible unmounting */
int prtactive = 0; /* 1 => print out reclaim of active vnodes */
/*
* 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 */
TAILQ_HEAD_INITIALIZER(vnode_free_list);
struct mntlist mountlist = /* mounted filesystem list */
CIRCLEQ_HEAD_INITIALIZER(mountlist);
struct device *root_device; /* root device */
int vfs_lock __P((struct mount *));
void vfs_unlock __P((struct mount *));
struct mount *getvfs __P((fsid_t *));
long makefstype __P((char *));
void vattr_null __P((struct vattr *));
int getnewvnode __P((enum vtagtype, struct mount *, int (**)(void *),
struct vnode **));
void insmntque __P((struct vnode *, struct mount *));
int vinvalbuf __P((struct vnode *, int, struct ucred *, struct proc *, int,
int));
void vflushbuf __P((struct vnode *, int));
void brelvp __P((struct buf *));
int bdevvp __P((dev_t, struct vnode **));
int cdevvp __P((dev_t, struct vnode **));
int getdevvp __P((dev_t, struct vnode **, enum vtype));
struct vnode *checkalias __P((struct vnode *, dev_t, struct mount *));
int vget __P((struct vnode *, int));
void vref __P((struct vnode *));
void vput __P((struct vnode *));
void vrele __P((struct vnode *));
void vhold __P((struct vnode *));
void holdrele __P((struct vnode *));
int vflush __P((struct mount *, struct vnode *, int));
void vgoneall __P((struct vnode *));
void vgone __P((struct vnode *));
int vcount __P((struct vnode *));
void vprint __P((char *, struct vnode *));
int vfs_mountedon __P((struct vnode *));
int vfs_export __P((struct mount *, struct netexport *, struct export_args *));
struct netcred *vfs_export_lookup __P((struct mount *, struct netexport *,
struct mbuf *));
int vaccess __P((enum vtype, mode_t, uid_t, gid_t, mode_t, struct ucred *));
void vfs_unmountall __P((void));
void vfs_shutdown __P((void));
static int vfs_hang_addrlist __P((struct mount *, struct netexport *,
struct export_args *));
static int vfs_free_netcred __P((struct radix_node *, void *));
static void vfs_free_addrlist __P((struct netexport *));
#ifdef DEBUG
void printlockedvnodes __P((void));
#endif
/*
* Initialize the vnode management data structures.
*/
void
vntblinit()
{
/*
* Nothing to do here anymore; vnode_free_list and mountlist
* are now initialized data.
*/
}
/*
* 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;
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.
*/
int
vfs_busy(mp)
register struct mount *mp;
{
int unmounting = mp->mnt_flag & MNT_UNMOUNT;
while(mp->mnt_flag & MNT_MPBUSY) {
mp->mnt_flag |= MNT_MPWANT;
tsleep((caddr_t)&mp->mnt_flag, PVFS, "vfsbusy", 0);
if (unmounting)
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);
}
}
/*
* 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 + 11, 0); /* XXX */
mp->mnt_stat.f_fsid.val[1] = mtype;
if (xxxfs_mntid == 0)
++xxxfs_mntid;
tfsid.val[0] = makedev((nblkdev + mtype) & 0xff, 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];
}
/*
* 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;
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
/* XXX These next two used to be one line, but for a GCC bug. */
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 int (**dead_vnodeop_p) __P((void *));
long numvnodes;
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
int (**vops) __P((void *));
struct vnode **vpp;
{
register struct vnode *vp;
#ifdef DIAGNOSTIC
int s;
#endif
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) {
vprint("free vnode", vp);
panic("free vnode isn't");
}
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
/* 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
if (vp->v_data) {
vprint("cleaned vnode", vp);
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_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) != NULL) {
if (--vp->v_numoutput < 0)
panic("vwakeup: neg numoutput");
if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
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;
if (flags & V_SAVE) {
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)) != 0)
return (error);
if (vp->v_dirtyblkhd.lh_first != NULL)
panic("vinvalbuf: dirty bufs");
}
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;
s = splbio();
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;
}
bp->b_flags |= B_BUSY | B_VFLUSH;
splx(s);
/*
* 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;
brelse(bp);
}
}
if (!(flags & V_SAVEMETA) &&
(vp->v_dirtyblkhd.lh_first || vp->v_cleanblkhd.lh_first))
panic("vinvalbuf: flush failed");
return (0);
}
void
vflushbuf(vp, sync)
register struct vnode *vp;
int sync;
{
register struct buf *bp, *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");
bp->b_flags |= B_BUSY | B_VFLUSH;
splx(s);
/*
* Wait for I/O associated with indirect blocks to complete,
* since there is no way to quickly wait for them below.
*/
if (bp->b_vp == vp || sync == 0)
(void) bawrite(bp);
else
(void) bwrite(bp);
goto loop;
}
if (sync == 0) {
splx(s);
return;
}
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vflushbuf", 0);
}
splx(s);
if (vp->v_dirtyblkhd.lh_first != NULL) {
vprint("vflushbuf: dirty", vp);
goto loop;
}
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
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.
*/
void
brelvp(bp)
register struct buf *bp;
{
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.
*/
void
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
register struct buflists *listheadp;
if (newvp == NULL) {
printf("reassignbuf: NULL");
return;
}
/*
* 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 and swap areas.
* Also used for memory file system special devices.
*/
int
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.
*/
int
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.
*/
int
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, NULL, spec_vnodeop_p, &nvp);
if (error) {
*vpp = NULLVP;
return (error);
}
vp = nvp;
vp->v_type = type;
if ((nvp = checkalias(vp, dev, NULL)) != 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;
nvp->v_speclockf = NULL;
*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;
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;
{
#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
/*
* insert at tail of LRU list
*/
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
VOP_INACTIVE(vp);
}
/*
* 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--;
}
/*
* 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 DEBUG
int busyprt = 0; /* print out busy vnodes */
struct ctldebug debug1 = { "busyprt", &busyprt };
#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) {
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;
/*
* 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 DEBUG
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(vp, flags)
register 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) != 0)
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;
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.
*/
insmntque(vp, (struct mount *)0);
/*
* 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) {
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 DEBUG
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
void
printlockedvnodes()
{
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 */
int
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.cqh_first; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_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);
}
/*
* 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(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);
error = copyin(argp->ex_addr, (caddr_t)saddr, argp->ex_addrlen);
if (error)
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]) != NULL) {
(*rnh->rnh_walktree)(rnh, vfs_free_netcred, 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)) != 0)
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);
}
/*
* Do the usual access checking.
* file_mode, uid and gid are from the vnode in question,
* while acc_mode and cred are from the VOP_ACCESS parameter list
*/
int
vaccess(type, file_mode, uid, gid, acc_mode, cred)
enum vtype type;
mode_t file_mode;
uid_t uid;
gid_t gid;
mode_t acc_mode;
struct ucred *cred;
{
mode_t mask;
/*
* Super-user always gets read/write access, but execute access depends
* on at least one execute bit being set.
*/
if (cred->cr_uid == 0) {
if ((acc_mode & VEXEC) && type != VDIR &&
(file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
return (EACCES);
return (0);
}
mask = 0;
/* Otherwise, check the owner. */
if (cred->cr_uid == uid) {
if (acc_mode & VEXEC)
mask |= S_IXUSR;
if (acc_mode & VREAD)
mask |= S_IRUSR;
if (acc_mode & VWRITE)
mask |= S_IWUSR;
return ((file_mode & mask) == mask ? 0 : EACCES);
}
/* Otherwise, check the groups. */
if (cred->cr_gid == gid || groupmember(gid, cred)) {
if (acc_mode & VEXEC)
mask |= S_IXGRP;
if (acc_mode & VREAD)
mask |= S_IRGRP;
if (acc_mode & VWRITE)
mask |= S_IWGRP;
return ((file_mode & mask) == mask ? 0 : EACCES);
}
/* Otherwise, check everyone else. */
if (acc_mode & VEXEC)
mask |= S_IXOTH;
if (acc_mode & VREAD)
mask |= S_IROTH;
if (acc_mode & VWRITE)
mask |= S_IWOTH;
return ((file_mode & mask) == mask ? 0 : EACCES);
}
/*
* Unmount all file systems.
* We traverse the list in reverse order under the assumption that doing so
* will avoid needing to worry about dependencies.
*/
void
vfs_unmountall()
{
register struct mount *mp, *nmp;
int allerror, error;
for (allerror = 0,
mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_prev;
#ifdef DEBUG
printf("unmounting %s (%s)...\n",
mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
#endif
if (vfs_busy(mp))
continue;
if ((error = dounmount(mp, MNT_FORCE, &proc0)) != 0) {
printf("unmount of %s failed with error %d\n",
mp->mnt_stat.f_mntonname, error);
allerror = 1;
}
}
if (allerror)
printf("WARNING: some file systems would not unmount\n");
}
/*
* Sync and unmount file systems before shutting down.
*/
void
vfs_shutdown()
{
register struct buf *bp;
int iter, nbusy;
printf("syncing disks... ");
/* XXX Should suspend scheduling. */
(void) spl0();
if (panicstr == 0) {
/* Release inodes held by texts before update. */
vnode_pager_umount(NULL);
#ifdef notdef
vnshutdown();
#endif
/* Sync before unmount, in case we hang on something. */
sys_sync(&proc0, (void *)0, (register_t *)0);
/* Unmount file systems. */
vfs_unmountall();
}
/* Sync again after unmount, just in case. */
sys_sync(&proc0, (void *)0, (register_t *)0);
/* Wait for sync to finish. */
for (iter = 0; iter < 20; iter++) {
nbusy = 0;
for (bp = &buf[nbuf]; --bp >= buf; )
if ((bp->b_flags & (B_BUSY|B_INVAL)) == B_BUSY)
nbusy++;
if (nbusy == 0)
break;
printf("%d ", nbusy);
DELAY(40000 * iter);
}
if (nbusy)
printf("giving up\n");
else
printf("done\n");
}
/*
* Mount the root file system. If the operator didn't specify a
* file system to use, try all possible file systems until one
* succeeds.
*/
int
vfs_mountroot()
{
extern int (*mountroot) __P((void));
int i;
if (root_device == NULL)
panic("vfs_mountroot: root device unknown");
switch (root_device->dv_class) {
case DV_IFNET:
if (rootdev != NODEV)
panic("vfs_mountroot: rootdev set for DV_IFNET");
break;
case DV_DISK:
if (rootdev == NODEV)
panic("vfs_mountroot: rootdev not set for DV_DISK");
break;
default:
printf("%s: inappropriate for root file system\n",
root_device->dv_xname);
return (ENODEV);
}
/*
* If user specified a file system, use it.
*/
if (mountroot != NULL)
return ((*mountroot)());
/*
* Try each file system currently configured into the kernel.
*/
for (i = 0; i < nvfssw; i++) {
if (vfssw[i] == NULL || vfssw[i]->vfs_mountroot == NULL)
continue;
#ifdef DEBUG
printf("mountroot: trying %s...\n", vfssw[i]->vfs_name);
#endif
if ((*vfssw[i]->vfs_mountroot)() == 0) {
printf("root file system type: %s\n",
vfssw[i]->vfs_name);
return (0);
}
}
printf("no file system for %s", root_device->dv_xname);
if (root_device->dv_class == DV_DISK)
printf(" (dev 0x%x)", rootdev);
printf("\n");
return (EFTYPE);
}
/*
* Given a file system name, look up the vfsops for that
* file system, or return NULL if file system isn't present
* in the kernel.
*/
struct vfsops *
vfs_getopsbyname(name)
const char *name;
{
int i;
for (i = 0; i < nvfssw; i++)
if (vfssw[i] != NULL && strcmp(vfssw[i]->vfs_name, name) == 0)
return (vfssw[i]);
return (NULL);
}
Reference in New Issue View Git Blame Copy Permalink