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freebsd-dev/sys/kern/vfs_export.c
phk 54bdf00508 Fix a race condition that did, after all, exist. 
Reviewed by:	phk
Submitted by:	dfr
1997-05-06 15:19:38 +00:00

2160 lines
51 KiB
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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
* $Id: vfs_subr.c,v 1.85 1997/05/04 09:17:29 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
static void vclean __P((struct vnode *vp, int flags, struct proc *p));
static void vgonel __P((struct vnode *vp, struct proc *p));
unsigned long numvnodes;
SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
static void vputrele __P((struct vnode *vp, int put));
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 */
struct simplelock mountlist_slock;
static struct simplelock mntid_slock;
struct simplelock mntvnode_slock;
struct simplelock vnode_free_list_slock;
static struct simplelock spechash_slock;
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;
simple_lock_init(&mntvnode_slock);
simple_lock_init(&mntid_slock);
simple_lock_init(&spechash_slock);
TAILQ_INIT(&vnode_free_list);
simple_lock_init(&vnode_free_list_slock);
CIRCLEQ_INIT(&mountlist);
}
/*
* Mark a mount point as busy. Used to synchronize access and to delay
* unmounting. Interlock is not released on failure.
*/
int
vfs_busy(mp, flags, interlkp, p)
struct mount *mp;
int flags;
struct simplelock *interlkp;
struct proc *p;
{
int lkflags;
if (mp->mnt_flag & MNT_UNMOUNT) {
if (flags & LK_NOWAIT)
return (ENOENT);
mp->mnt_flag |= MNT_MWAIT;
if (interlkp) {
simple_unlock(interlkp);
}
/*
* Since all busy locks are shared except the exclusive
* lock granted when unmounting, the only place that a
* wakeup needs to be done is at the release of the
* exclusive lock at the end of dounmount.
*/
tsleep((caddr_t)mp, PVFS, "vfs_busy", 0);
if (interlkp) {
simple_lock(interlkp);
}
return (ENOENT);
}
lkflags = LK_SHARED;
if (interlkp)
lkflags |= LK_INTERLOCK;
if (lockmgr(&mp->mnt_lock, lkflags, interlkp, p))
panic("vfs_busy: unexpected lock failure");
return (0);
}
/*
* Free a busy filesystem.
*/
void
vfs_unbusy(mp, p)
struct mount *mp;
struct proc *p;
{
lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, p);
}
/*
* Lookup a filesystem type, and if found allocate and initialize
* a mount structure for it.
*
* Devname is usually updated by mount(8) after booting.
*/
int
vfs_rootmountalloc(fstypename, devname, mpp)
char *fstypename;
char *devname;
struct mount **mpp;
{
struct proc *p = curproc; /* XXX */
struct vfsconf *vfsp;
struct mount *mp;
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstypename))
break;
if (vfsp == NULL)
return (ENODEV);
mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
bzero((char *)mp, (u_long)sizeof(struct mount));
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0);
(void)vfs_busy(mp, LK_NOWAIT, 0, p);
LIST_INIT(&mp->mnt_vnodelist);
mp->mnt_vfc = vfsp;
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_flag = MNT_RDONLY;
mp->mnt_vnodecovered = NULLVP;
vfsp->vfc_refcount++;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_stat.f_mntonname[0] = '/';
mp->mnt_stat.f_mntonname[1] = 0;
(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
*mpp = mp;
return (0);
}
/*
* Find an appropriate filesystem to use for the root. If a filesystem
* has not been preselected, walk through the list of known filesystems
* trying those that have mountroot routines, and try them until one
* works or we have tried them all.
*/
#ifdef notdef /* XXX JH */
int
lite2_vfs_mountroot(void)
{
struct vfsconf *vfsp;
extern int (*lite2_mountroot)(void);
int error;
if (lite2_mountroot != NULL)
return ((*lite2_mountroot)());
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
if (vfsp->vfc_mountroot == NULL)
continue;
if ((error = (*vfsp->vfc_mountroot)()) == 0)
return (0);
printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error);
}
return (ENODEV);
}
#endif
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
vfs_getvfs(fsid)
fsid_t *fsid;
{
register struct mount *mp;
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist;
mp = mp->mnt_list.cqe_next) {
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
simple_unlock(&mountlist_slock);
return (mp);
}
}
simple_unlock(&mountlist_slock);
return ((struct mount *) 0);
}
/*
* Get a new unique fsid
*/
void
vfs_getnewfsid(mp)
struct mount *mp;
{
static u_short xxxfs_mntid;
fsid_t tfsid;
int mtype;
simple_lock(&mntid_slock);
mtype = mp->mnt_vfc->vfc_typenum;
mp->mnt_stat.f_fsid.val[0] = makedev(nblkdev + mtype, 0);
mp->mnt_stat.f_fsid.val[1] = mtype;
if (xxxfs_mntid == 0)
++xxxfs_mntid;
tfsid.val[0] = makedev(nblkdev + mtype, xxxfs_mntid);
tfsid.val[1] = mtype;
if (mountlist.cqh_first != (void *)&mountlist) {
while (vfs_getvfs(&tfsid)) {
tfsid.val[0]++;
xxxfs_mntid++;
}
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
simple_unlock(&mntid_slock);
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
vap->va_size = VNOVAL;
vap->va_bytes = VNOVAL;
vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid =
vap->va_fsid = vap->va_fileid =
vap->va_blocksize = vap->va_rdev =
vap->va_atime.tv_sec = vap->va_atime.tv_nsec =
vap->va_mtime.tv_sec = vap->va_mtime.tv_nsec =
vap->va_ctime.tv_sec = vap->va_ctime.tv_nsec =
vap->va_flags = vap->va_gen = VNOVAL;
vap->va_vaflags = 0;
}
/*
* Routines having to do with the management of the vnode table.
*/
extern vop_t **dead_vnodeop_p;
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
vop_t **vops;
struct vnode **vpp;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp;
/*
* We take the least recently used vnode from the freelist
* if we can get it and it has no cached pages, and no
* namecache entries are relative to it.
* Otherwise we allocate a new vnode
*/
simple_lock(&vnode_free_list_slock);
TAILQ_FOREACH(vp, &vnode_free_list, v_freelist) {
if (!simple_lock_try(&vp->v_interlock))
continue;
if (vp->v_usecount)
panic("free vnode isn't");
if (vp->v_object && vp->v_object->resident_page_count) {
/* Don't recycle if it's caching some pages */
simple_unlock(&vp->v_interlock);
continue;
} else if (LIST_FIRST(&vp->v_cache_src)) {
/* Don't recycle if active in the namecache */
simple_unlock(&vp->v_interlock);
continue;
} else {
break;
}
}
if (vp) {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
freevnodes--;
/* see comment on why 0xdeadb is set at end of vgone (below) */
vp->v_freelist.tqe_prev = (struct vnode **) 0xdeadb;
simple_unlock(&vnode_free_list_slock);
vp->v_lease = NULL;
if (vp->v_type != VBAD)
vgonel(vp, p);
else {
simple_unlock(&vp->v_interlock);
}
#ifdef DIAGNOSTIC
{
int s;
if (vp->v_data)
panic("cleaned vnode isn't");
s = splbio();
if (vp->v_numoutput)
panic("Clean vnode has pending I/O's");
splx(s);
}
#endif
vp->v_flag = 0;
vp->v_lastr = 0;
vp->v_lastw = 0;
vp->v_lasta = 0;
vp->v_cstart = 0;
vp->v_clen = 0;
vp->v_socket = 0;
vp->v_writecount = 0; /* XXX */
} else {
simple_unlock(&vnode_free_list_slock);
vp = (struct vnode *) malloc((u_long) sizeof *vp,
M_VNODE, M_WAITOK);
bzero((char *) vp, sizeof *vp);
vp->v_dd = vp;
LIST_INIT(&vp->v_cache_src);
TAILQ_INIT(&vp->v_cache_dst);
numvnodes++;
}
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;
{
simple_lock(&mntvnode_slock);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
LIST_REMOVE(vp, v_mntvnodes);
/*
* Insert into list of vnodes for the new mount point, if available.
*/
if ((vp->v_mount = mp) == NULL) {
simple_unlock(&mntvnode_slock);
return;
}
LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes);
simple_unlock(&mntvnode_slock);
}
/*
* Update outstanding I/O count and do wakeup if requested.
*/
void
vwakeup(bp)
register struct buf *bp;
{
register struct vnode *vp;
bp->b_flags &= ~B_WRITEINPROG;
if ((vp = bp->b_vp)) {
vp->v_numoutput--;
if (vp->v_numoutput < 0)
panic("vwakeup: neg numoutput");
if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t) &vp->v_numoutput);
}
}
}
/*
* Flush out and invalidate all buffers associated with a vnode.
* Called with the underlying object locked.
*/
int
vinvalbuf(vp, flags, cred, p, slpflag, slptimeo)
register struct vnode *vp;
int flags;
struct ucred *cred;
struct proc *p;
int slpflag, slptimeo;
{
register struct buf *bp;
struct buf *nbp, *blist;
int s, error;
vm_object_t object;
if (flags & V_SAVE) {
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)))
return (error);
if (vp->v_dirtyblkhd.lh_first != NULL)
panic("vinvalbuf: dirty bufs");
}
s = splbio();
for (;;) {
if ((blist = vp->v_cleanblkhd.lh_first) && (flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist && (blist = vp->v_dirtyblkhd.lh_first) &&
(flags & V_SAVEMETA))
while (blist && blist->b_lblkno < 0)
blist = blist->b_vnbufs.le_next;
if (!blist)
break;
for (bp = blist; bp; bp = nbp) {
nbp = bp->b_vnbufs.le_next;
if ((flags & V_SAVEMETA) && bp->b_lblkno < 0)
continue;
if (bp->b_flags & B_BUSY) {
bp->b_flags |= B_WANTED;
error = tsleep((caddr_t) bp,
slpflag | (PRIBIO + 1), "vinvalbuf",
slptimeo);
if (error) {
splx(s);
return (error);
}
break;
}
bremfree(bp);
bp->b_flags |= B_BUSY;
/*
* XXX Since there are no node locks for NFS, I
* believe there is a slight chance that a delayed
* write will occur while sleeping just above, so
* check for it.
*/
if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) {
(void) VOP_BWRITE(bp);
break;
}
bp->b_flags |= (B_INVAL|B_NOCACHE|B_RELBUF);
brelse(bp);
}
}
while (vp->v_numoutput > 0) {
vp->v_flag |= VBWAIT;
tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0);
}
splx(s);
/*
* Destroy the copy in the VM cache, too.
*/
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 defined(DIAGNOSTIC)
if (bp->b_vp)
panic("pbgetvp: not free");
#endif
bp->b_vp = vp;
if (vp->v_type == VBLK || vp->v_type == VCHR)
bp->b_dev = vp->v_rdev;
else
bp->b_dev = NODEV;
}
/*
* Disassociate a p-buffer from a vnode.
*/
void
pbrelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
#if defined(DIAGNOSTIC)
if (bp->b_vp == (struct vnode *) 0)
panic("pbrelvp: NULL");
#endif
bp->b_vp = (struct vnode *) 0;
}
/*
* Reassign a buffer from one vnode to another.
* Used to assign file specific control information
* (indirect blocks) to the vnode to which they belong.
*/
void
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
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;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp;
struct vnode **vpp;
if (nvp->v_type != VBLK && nvp->v_type != VCHR)
return (NULLVP);
vpp = &speclisth[SPECHASH(nvp_rdev)];
loop:
simple_lock(&spechash_slock);
for (vp = *vpp; vp; vp = vp->v_specnext) {
if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type)
continue;
/*
* Alias, but not in use, so flush it out.
*/
simple_lock(&vp->v_interlock);
if (vp->v_usecount == 0) {
simple_unlock(&spechash_slock);
vgonel(vp, p);
goto loop;
}
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) {
simple_unlock(&spechash_slock);
goto loop;
}
break;
}
if (vp == NULL || vp->v_tag != VT_NON) {
MALLOC(nvp->v_specinfo, struct specinfo *,
sizeof(struct specinfo), M_VNODE, M_WAITOK);
nvp->v_rdev = nvp_rdev;
nvp->v_hashchain = vpp;
nvp->v_specnext = *vpp;
nvp->v_specflags = 0;
simple_unlock(&spechash_slock);
*vpp = nvp;
if (vp != NULLVP) {
nvp->v_flag |= VALIASED;
vp->v_flag |= VALIASED;
vput(vp);
}
return (NULLVP);
}
simple_unlock(&spechash_slock);
VOP_UNLOCK(vp, 0, p);
simple_lock(&vp->v_interlock);
vclean(vp, 0, p);
vp->v_op = nvp->v_op;
vp->v_tag = nvp->v_tag;
nvp->v_type = VNON;
insmntque(vp, mp);
return (vp);
}
/*
* Grab a particular vnode from the free list, increment its
* reference count and lock it. The vnode lock bit is set the
* vnode is being eliminated in vgone. The process is awakened
* when the transition is completed, and an error returned to
* indicate that the vnode is no longer usable (possibly having
* been changed to a new file system type).
*/
int
vget(vp, flags, p)
register struct vnode *vp;
int flags;
struct proc *p;
{
int error;
/*
* If the vnode is in the process of being cleaned out for
* another use, we wait for the cleaning to finish and then
* return failure. Cleaning is determined by checking that
* the VXLOCK flag is set.
*/
if ((flags & LK_INTERLOCK) == 0) {
simple_lock(&vp->v_interlock);
}
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vget", 0);
return (ENOENT);
}
if (vp->v_usecount == 0) {
simple_lock(&vnode_free_list_slock);
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
simple_unlock(&vnode_free_list_slock);
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)) {
/*
* XXX vfs_object_create probably needs the interlock.
*/
simple_unlock(&vp->v_interlock);
vfs_object_create(vp, curproc, curproc->p_ucred, 0);
simple_lock(&vp->v_interlock);
}
if (flags & LK_TYPE_MASK) {
if (error = vn_lock(vp, flags | LK_INTERLOCK, p))
vrele(vp);
return (error);
}
simple_unlock(&vp->v_interlock);
return (0);
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
* A minimal shared lock is necessary to ensure that the underlying object
* is not revoked while an operation is in progress. So, an active shared
* count is maintained in an auxillary vnode lock structure.
*/
int
vop_sharedlock(ap)
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct proc *a_p;
} */ *ap;
{
/*
* This code cannot be used until all the non-locking filesystems
* (notably NFS) are converted to properly lock and release nodes.
* Also, certain vnode operations change the locking state within
* the operation (create, mknod, remove, link, rename, mkdir, rmdir,
* and symlink). Ideally these operations should not change the
* lock state, but should be changed to let the caller of the
* function unlock them. Otherwise all intermediate vnode layers
* (such as union, umapfs, etc) must catch these functions to do
* the necessary locking at their layer. Note that the inactive
* and lookup operations also change their lock state, but this
* cannot be avoided, so these two operations will always need
* to be handled in intermediate layers.
*/
struct vnode *vp = ap->a_vp;
int vnflags, flags = ap->a_flags;
if (vp->v_vnlock == NULL) {
if ((flags & LK_TYPE_MASK) == LK_DRAIN)
return (0);
MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock),
M_VNODE, M_WAITOK);
lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0);
}
switch (flags & LK_TYPE_MASK) {
case LK_DRAIN:
vnflags = LK_DRAIN;
break;
case LK_EXCLUSIVE:
#ifdef DEBUG_VFS_LOCKS
/*
* Normally, we use shared locks here, but that confuses
* the locking assertions.
*/
vnflags = LK_EXCLUSIVE;
break;
#endif
case LK_SHARED:
vnflags = LK_SHARED;
break;
case LK_UPGRADE:
case LK_EXCLUPGRADE:
case LK_DOWNGRADE:
return (0);
case LK_RELEASE:
default:
panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK);
}
if (flags & LK_INTERLOCK)
vnflags |= LK_INTERLOCK;
return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p));
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
* A minimal shared lock is necessary to ensure that the underlying object
* is not revoked while an operation is in progress. So, an active shared
* count is maintained in an auxillary vnode lock structure.
*/
int
vop_nolock(ap)
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct proc *a_p;
} */ *ap;
{
#ifdef notyet
/*
* This code cannot be used until all the non-locking filesystems
* (notably NFS) are converted to properly lock and release nodes.
* Also, certain vnode operations change the locking state within
* the operation (create, mknod, remove, link, rename, mkdir, rmdir,
* and symlink). Ideally these operations should not change the
* lock state, but should be changed to let the caller of the
* function unlock them. Otherwise all intermediate vnode layers
* (such as union, umapfs, etc) must catch these functions to do
* the necessary locking at their layer. Note that the inactive
* and lookup operations also change their lock state, but this
* cannot be avoided, so these two operations will always need
* to be handled in intermediate layers.
*/
struct vnode *vp = ap->a_vp;
int vnflags, flags = ap->a_flags;
if (vp->v_vnlock == NULL) {
if ((flags & LK_TYPE_MASK) == LK_DRAIN)
return (0);
MALLOC(vp->v_vnlock, struct lock *, sizeof(struct lock),
M_VNODE, M_WAITOK);
lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0);
}
switch (flags & LK_TYPE_MASK) {
case LK_DRAIN:
vnflags = LK_DRAIN;
break;
case LK_EXCLUSIVE:
case LK_SHARED:
vnflags = LK_SHARED;
break;
case LK_UPGRADE:
case LK_EXCLUPGRADE:
case LK_DOWNGRADE:
return (0);
case LK_RELEASE:
default:
panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK);
}
if (flags & LK_INTERLOCK)
vnflags |= LK_INTERLOCK;
return(lockmgr(vp->v_vnlock, vnflags, &vp->v_interlock, ap->a_p));
#else /* for now */
/*
* Since we are not using the lock manager, we must clear
* the interlock here.
*/
if (ap->a_flags & LK_INTERLOCK) {
simple_unlock(&ap->a_vp->v_interlock);
}
return (0);
#endif
}
/*
* Do the inverse of vop_nolock, handling the interlock in a compatible way.
*/
int
vop_nounlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
if (vp->v_vnlock == NULL) {
if (ap->a_flags & LK_INTERLOCK)
simple_unlock(&ap->a_vp->v_interlock);
return (0);
}
return (lockmgr(vp->v_vnlock, LK_RELEASE | ap->a_flags,
&ap->a_vp->v_interlock, ap->a_p));
}
/*
* Return whether or not the node is in use.
*/
int
vop_noislocked(ap)
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
if (vp->v_vnlock == NULL)
return (0);
return (lockstatus(vp->v_vnlock));
}
/* #ifdef DIAGNOSTIC */
/*
* Vnode reference, just increment the count
*/
void
vref(vp)
struct vnode *vp;
{
simple_lock(&vp->v_interlock);
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.
* XXX vfs_object_create probably needs the interlock?
*/
simple_unlock(&vp->v_interlock);
vfs_object_create(vp, curproc, curproc->p_ucred, 0);
return;
}
simple_unlock(&vp->v_interlock);
}
/*
* Vnode put/release.
* If count drops to zero, call inactive routine and return to freelist.
*/
static void
vputrele(vp, put)
struct vnode *vp;
int put;
{
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if (vp == NULL)
panic("vputrele: null vp");
#endif
simple_lock(&vp->v_interlock);
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;
if (put) {
VOP_UNLOCK(vp, LK_INTERLOCK, p);
} else {
simple_unlock(&vp->v_interlock);
}
vm_object_deallocate(vp->v_object);
return;
}
if (vp->v_usecount > 0) {
if (put) {
VOP_UNLOCK(vp, LK_INTERLOCK, p);
} else {
simple_unlock(&vp->v_interlock);
}
return;
}
if (vp->v_usecount < 0) {
#ifdef DIAGNOSTIC
vprint("vputrele: negative ref count", vp);
#endif
panic("vputrele: negative ref cnt");
}
simple_lock(&vnode_free_list_slock);
if (vp->v_flag & VAGE) {
vp->v_flag &= ~VAGE;
if(vp->v_tag != VT_TFS)
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
} else {
if(vp->v_tag != VT_TFS)
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
freevnodes++;
simple_unlock(&vnode_free_list_slock);
/*
* If we are doing a vput, the node is already locked, and we must
* call VOP_INACTIVE with the node locked. So, in the case of
* vrele, we explicitly lock the vnode before calling VOP_INACTIVE.
*/
if (put) {
simple_unlock(&vp->v_interlock);
VOP_INACTIVE(vp, p);
} else if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, p) == 0) {
VOP_INACTIVE(vp, p);
}
}
/*
* vput(), just unlock and vrele()
*/
void
vput(vp)
struct vnode *vp;
{
vputrele(vp, 1);
}
void
vrele(vp)
struct vnode *vp;
{
vputrele(vp, 0);
}
#ifdef DIAGNOSTIC
/*
* Page or buffer structure gets a reference.
*/
void
vhold(vp)
register struct vnode *vp;
{
simple_lock(&vp->v_interlock);
vp->v_holdcnt++;
simple_unlock(&vp->v_interlock);
}
/*
* Page or buffer structure frees a reference.
*/
void
holdrele(vp)
register struct vnode *vp;
{
simple_lock(&vp->v_interlock);
if (vp->v_holdcnt <= 0)
panic("holdrele: holdcnt");
vp->v_holdcnt--;
simple_unlock(&vp->v_interlock);
}
#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, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
#endif
int
vflush(mp, skipvp, flags)
struct mount *mp;
struct vnode *skipvp;
int flags;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp, *nvp;
int busy = 0;
simple_lock(&mntvnode_slock);
loop:
for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) {
/*
* Make sure this vnode wasn't reclaimed in getnewvnode().
* Start over if it has (it won't be on the list anymore).
*/
if (vp->v_mount != mp)
goto loop;
nvp = vp->v_mntvnodes.le_next;
/*
* Skip over a selected vnode.
*/
if (vp == skipvp)
continue;
simple_lock(&vp->v_interlock);
/*
* Skip over a vnodes marked VSYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
simple_unlock(&vp->v_interlock);
continue;
}
/*
* If WRITECLOSE is set, only flush out regular file vnodes
* open for writing.
*/
if ((flags & WRITECLOSE) &&
(vp->v_writecount == 0 || vp->v_type != VREG)) {
simple_unlock(&vp->v_interlock);
continue;
}
if (vp->v_object && (vp->v_object->flags & OBJ_VFS_REF)) {
simple_unlock(&vp->v_interlock);
simple_unlock(&mntvnode_slock);
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);
simple_lock(&mntvnode_slock);
simple_lock(&vp->v_interlock);
}
/*
* With v_usecount == 0, all we need to do is clear out the
* vnode data structures and we are done.
*/
if (vp->v_usecount == 0) {
simple_unlock(&mntvnode_slock);
vgonel(vp, p);
simple_lock(&mntvnode_slock);
continue;
}
/*
* If FORCECLOSE is set, forcibly close the vnode. For block
* or character devices, revert to an anonymous device. For
* all other files, just kill them.
*/
if (flags & FORCECLOSE) {
simple_unlock(&mntvnode_slock);
if (vp->v_type != VBLK && vp->v_type != VCHR) {
vgonel(vp, p);
} else {
vclean(vp, 0, p);
vp->v_op = spec_vnodeop_p;
insmntque(vp, (struct mount *) 0);
}
simple_lock(&mntvnode_slock);
continue;
}
#ifdef DIAGNOSTIC
if (busyprt)
vprint("vflush: busy vnode", vp);
#endif
simple_unlock(&vp->v_interlock);
busy++;
}
simple_unlock(&mntvnode_slock);
if (busy)
return (EBUSY);
return (0);
}
/*
* Disassociate the underlying file system from a vnode.
*/
static void
vclean(struct vnode *vp, int flags, struct proc *p)
{
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))
vp->v_usecount++;
/*
* Prevent the vnode from being recycled or brought into use while we
* clean it out.
*/
if (vp->v_flag & VXLOCK)
panic("vclean: deadlock");
vp->v_flag |= VXLOCK;
/*
* Even if the count is zero, the VOP_INACTIVE routine may still
* have the object locked while it cleans it out. The VOP_LOCK
* ensures that the VOP_INACTIVE routine is done with its work.
* For active vnodes, it ensures that no other activity can
* occur while the underlying object is being cleaned out.
*/
VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, p);
/*
* Clean out any buffers associated with the vnode.
*/
if (flags & DOCLOSE)
vinvalbuf(vp, V_SAVE, NOCRED, p, 0, 0);
/*
* If purging an active vnode, it must be closed and
* deactivated before being reclaimed. Note that the
* VOP_INACTIVE will unlock the vnode.
*/
if (active) {
if (flags & DOCLOSE)
VOP_CLOSE(vp, IO_NDELAY, NOCRED, p);
VOP_INACTIVE(vp, p);
} else {
/*
* Any other processes trying to obtain this lock must first
* wait for VXLOCK to clear, then call the new lock operation.
*/
VOP_UNLOCK(vp, 0, p);
}
/*
* Reclaim the vnode.
*/
if (VOP_RECLAIM(vp, p))
panic("vclean: cannot reclaim");
if (active)
vrele(vp);
cache_purge(vp);
if (vp->v_vnlock) {
#ifdef DIAGNOSTIC
if ((vp->v_vnlock->lk_flags & LK_DRAINED) == 0)
vprint("vclean: lock not drained", vp);
#endif
FREE(vp->v_vnlock, M_VNODE);
vp->v_vnlock = NULL;
}
/*
* 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.
*/
int
vop_revoke(ap)
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap;
{
struct vnode *vp, *vq;
struct proc *p = curproc; /* XXX */
#ifdef DIAGNOSTIC
if ((ap->a_flags & REVOKEALL) == 0)
panic("vop_revoke");
#endif
vp = ap->a_vp;
simple_lock(&vp->v_interlock);
if (vp->v_flag & VALIASED) {
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0);
return (0);
}
/*
* Ensure that vp will not be vgone'd while we
* are eliminating its aliases.
*/
vp->v_flag |= VXLOCK;
simple_unlock(&vp->v_interlock);
while (vp->v_flag & VALIASED) {
simple_lock(&spechash_slock);
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type || vp == vq)
continue;
simple_unlock(&spechash_slock);
vgone(vq);
break;
}
if (vq == NULLVP) {
simple_unlock(&spechash_slock);
}
}
/*
* Remove the lock so that vgone below will
* really eliminate the vnode after which time
* vgone will awaken any sleepers.
*/
simple_lock(&vp->v_interlock);
vp->v_flag &= ~VXLOCK;
}
vgonel(vp, p);
return (0);
}
/*
* Recycle an unused vnode to the front of the free list.
* Release the passed interlock if the vnode will be recycled.
*/
int
vrecycle(vp, inter_lkp, p)
struct vnode *vp;
struct simplelock *inter_lkp;
struct proc *p;
{
simple_lock(&vp->v_interlock);
if (vp->v_usecount == 0) {
if (inter_lkp) {
simple_unlock(inter_lkp);
}
vgonel(vp, p);
return (1);
}
simple_unlock(&vp->v_interlock);
return (0);
}
/*
* Eliminate all activity associated with a vnode
* in preparation for reuse.
*/
void
vgone(vp)
register struct vnode *vp;
{
struct proc *p = curproc; /* XXX */
simple_lock(&vp->v_interlock);
vgonel(vp, p);
}
/*
* vgone, with the vp interlock held.
*/
static void
vgonel(vp, p)
struct vnode *vp;
struct proc *p;
{
struct vnode *vq;
struct vnode *vx;
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
simple_unlock(&vp->v_interlock);
tsleep((caddr_t)vp, PINOD, "vgone", 0);
return;
}
if (vp->v_object) {
vp->v_object->flags |= OBJ_VNODE_GONE;
}
/*
* Clean out the filesystem specific data.
*/
vclean(vp, DOCLOSE, p);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
insmntque(vp, (struct mount *)0);
/*
* If special device, remove it from special device alias list
* if it is on one.
*/
if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_specinfo != 0) {
simple_lock(&spechash_slock);
if (*vp->v_hashchain == vp) {
*vp->v_hashchain = vp->v_specnext;
} else {
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_specnext != vp)
continue;
vq->v_specnext = vp->v_specnext;
break;
}
if (vq == NULL)
panic("missing bdev");
}
if (vp->v_flag & VALIASED) {
vx = NULL;
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type)
continue;
if (vx)
break;
vx = vq;
}
if (vx == NULL)
panic("missing alias");
if (vq == NULL)
vx->v_flag &= ~VALIASED;
vp->v_flag &= ~VALIASED;
}
simple_unlock(&spechash_slock);
FREE(vp->v_specinfo, M_VNODE);
vp->v_specinfo = NULL;
}
/*
* If it is on the freelist and not already at the head,
* move it to the head of the list. The test of the back
* pointer and the reference count of zero is because
* it will be removed from the free list by getnewvnode,
* but will not have its reference count incremented until
* after calling vgone. If the reference count were
* incremented first, vgone would (incorrectly) try to
* close the previous instance of the underlying object.
* 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) {
simple_lock(&vnode_free_list_slock);
if ((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);
}
simple_unlock(&vnode_free_list_slock);
}
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;
int rc = 0;
simple_lock(&spechash_slock);
for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
if (dev != vp->v_rdev || type != vp->v_type)
continue;
*vpp = vp;
rc = 1;
break;
}
simple_unlock(&spechash_slock);
return (rc);
}
/*
* Calculate the total number of references to a special device.
*/
int
vcount(vp)
register struct vnode *vp;
{
struct vnode *vq, *vnext;
int count;
loop:
if ((vp->v_flag & VALIASED) == 0)
return (vp->v_usecount);
simple_lock(&spechash_slock);
for (count = 0, vq = *vp->v_hashchain; vq; vq = vnext) {
vnext = vq->v_specnext;
if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type)
continue;
/*
* Alias, but not in use, so flush it out.
*/
if (vq->v_usecount == 0 && vq != vp) {
simple_unlock(&spechash_slock);
vgone(vq);
goto loop;
}
count += vq->v_usecount;
}
simple_unlock(&spechash_slock);
return (count);
}
/*
* Print out a description of a vnode.
*/
static char *typename[] =
{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
void
vprint(label, vp)
char *label;
register struct vnode *vp;
{
char buf[64];
if (label != NULL)
printf("%s: %x: ", label, vp);
else
printf("%x: ", vp);
printf("type %s, usecount %d, writecount %d, refcount %ld,",
typename[vp->v_type], vp->v_usecount, vp->v_writecount,
vp->v_holdcnt);
buf[0] = '\0';
if (vp->v_flag & VROOT)
strcat(buf, "|VROOT");
if (vp->v_flag & VTEXT)
strcat(buf, "|VTEXT");
if (vp->v_flag & VSYSTEM)
strcat(buf, "|VSYSTEM");
if (vp->v_flag & VXLOCK)
strcat(buf, "|VXLOCK");
if (vp->v_flag & VXWANT)
strcat(buf, "|VXWANT");
if (vp->v_flag & VBWAIT)
strcat(buf, "|VBWAIT");
if (vp->v_flag & VALIASED)
strcat(buf, "|VALIASED");
if (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()
{
struct proc *p = curproc; /* XXX */
struct mount *mp, *nmp;
struct vnode *vp;
printf("Locked vnodes\n");
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
nmp = mp->mnt_list.cqe_next;
continue;
}
for (vp = mp->mnt_vnodelist.lh_first;
vp != NULL;
vp = vp->v_mntvnodes.le_next) {
if (VOP_ISLOCKED(vp))
vprint((char *)0, vp);
}
simple_lock(&mountlist_slock);
nmp = mp->mnt_list.cqe_next;
vfs_unbusy(mp, p);
}
simple_unlock(&mountlist_slock);
}
#endif
/*
* Top level filesystem related information gathering.
*/
static int sysctl_ovfs_conf __P(SYSCTL_HANDLER_ARGS);
static int
vfs_sysctl SYSCTL_HANDLER_ARGS
{
int *name = (int *)arg1 - 1; /* XXX */
u_int namelen = arg2 + 1; /* XXX */
struct vfsconf *vfsp;
#ifndef NO_COMPAT_PRELITE2
/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
if (namelen == 1)
return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
#endif
#ifdef notyet
/* all sysctl names at this level are at least name and field */
if (namelen < 2)
return (ENOTDIR); /* overloaded */
if (name[0] != VFS_GENERIC) {
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[0])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
oldp, oldlenp, newp, newlen, p));
}
#endif
switch (name[1]) {
case VFS_MAXTYPENUM:
if (namelen != 2)
return (ENOTDIR);
return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
case VFS_CONF:
if (namelen != 3)
return (ENOTDIR); /* overloaded */
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[2])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
}
return (EOPNOTSUPP);
}
SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
"Generic filesystem");
#ifndef NO_COMPAT_PRELITE2
static int
sysctl_ovfs_conf SYSCTL_HANDLER_ARGS
{
int error;
struct vfsconf *vfsp;
struct ovfsconf ovfs;
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
strcpy(ovfs.vfc_name, vfsp->vfc_name);
ovfs.vfc_index = vfsp->vfc_typenum;
ovfs.vfc_refcount = vfsp->vfc_refcount;
ovfs.vfc_flags = vfsp->vfc_flags;
error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
if (error)
return error;
}
return 0;
}
#endif /* !NO_COMPAT_PRELITE2 */
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
{
struct proc *p = curproc; /* XXX */
struct mount *mp, *nmp;
struct vnode *nvp, *vp;
int error;
#define VPTRSZ sizeof (struct vnode *)
#define VNODESZ sizeof (struct vnode)
req->lock = 0;
if (!req->oldptr) /* Make an estimate */
return (SYSCTL_OUT(req, 0,
(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
simple_lock(&mountlist_slock);
for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
nmp = mp->mnt_list.cqe_next;
continue;
}
again:
simple_lock(&mntvnode_slock);
for (vp = mp->mnt_vnodelist.lh_first;
vp != NULL;
vp = nvp) {
/*
* Check that the vp is still associated with
* this filesystem. RACE: could have been
* recycled onto the same filesystem.
*/
if (vp->v_mount != mp) {
simple_unlock(&mntvnode_slock);
if (kinfo_vdebug)
printf("kinfo: vp changed\n");
goto again;
}
nvp = vp->v_mntvnodes.le_next;
simple_unlock(&mntvnode_slock);
if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
(error = SYSCTL_OUT(req, vp, VNODESZ)))
return (error);
simple_lock(&mntvnode_slock);
}
simple_unlock(&mntvnode_slock);
simple_lock(&mountlist_slock);
nmp = mp->mnt_list.cqe_next;
vfs_unbusy(mp, p);
}
simple_unlock(&mountlist_slock);
return (0);
}
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)
struct vnode *vp;
{
struct vnode *vq;
int error = 0;
if (vp->v_specflags & SI_MOUNTEDON)
return (EBUSY);
if (vp->v_flag & VALIASED) {
simple_lock(&spechash_slock);
for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type)
continue;
if (vq->v_specflags & SI_MOUNTEDON) {
error = EBUSY;
break;
}
}
simple_unlock(&spechash_slock);
}
return (error);
}
/*
* Unmount all filesystems. The list is traversed in reverse order
* of mounting to avoid dependencies.
*/
void
vfs_unmountall()
{
struct mount *mp, *nmp;
struct proc *p = initproc; /* XXX XXX should this be proc0? */
int error;
/*
* Since this only runs when rebooting, it is not interlocked.
*/
for (mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_prev;
error = dounmount(mp, MNT_FORCE, p);
if (error) {
printf("unmount of %s failed (",
mp->mnt_stat.f_mntonname);
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
}
}
}
/*
* Build hash lists of net addresses and hang them off the mount point.
* Called by ufs_mount() to set up the lists of export addresses.
*/
static int
vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
struct export_args *argp)
{
register struct netcred *np;
register struct radix_node_head *rnh;
register int i;
struct radix_node *rn;
struct sockaddr *saddr, *smask = 0;
struct domain *dom;
int error;
if (argp->ex_addrlen == 0) {
if (mp->mnt_flag & MNT_DEFEXPORTED)
return (EPERM);
np = &nep->ne_defexported;
np->netc_exflags = argp->ex_flags;
np->netc_anon = argp->ex_anon;
np->netc_anon.cr_ref = 1;
mp->mnt_flag |= MNT_DEFEXPORTED;
return (0);
}
i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK);
bzero((caddr_t) np, i);
saddr = (struct sockaddr *) (np + 1);
if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
goto out;
if (saddr->sa_len > argp->ex_addrlen)
saddr->sa_len = argp->ex_addrlen;
if (argp->ex_masklen) {
smask = (struct sockaddr *) ((caddr_t) saddr + argp->ex_addrlen);
error = copyin(argp->ex_mask, (caddr_t) smask, argp->ex_masklen);
if (error)
goto out;
if (smask->sa_len > argp->ex_masklen)
smask->sa_len = argp->ex_masklen;
}
i = saddr->sa_family;
if ((rnh = nep->ne_rtable[i]) == 0) {
/*
* Seems silly to initialize every AF when most are not used,
* do so on demand here
*/
for (dom = domains; dom; dom = dom->dom_next)
if (dom->dom_family == i && dom->dom_rtattach) {
dom->dom_rtattach((void **) &nep->ne_rtable[i],
dom->dom_rtoffset);
break;
}
if ((rnh = nep->ne_rtable[i]) == 0) {
error = ENOBUFS;
goto out;
}
}
rn = (*rnh->rnh_addaddr) ((caddr_t) saddr, (caddr_t) smask, rnh,
np->netc_rnodes);
if (rn == 0 || np != (struct netcred *) rn) { /* already exists */
error = EPERM;
goto out;
}
np->netc_exflags = argp->ex_flags;
np->netc_anon = argp->ex_anon;
np->netc_anon.cr_ref = 1;
return (0);
out:
free(np, M_NETADDR);
return (error);
}
/* ARGSUSED */
static int
vfs_free_netcred(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, 0, p);
tsleep(object, PVM, "vodead", 0);
if (waslocked)
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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;
}
void
vtouch(vp)
struct vnode *vp;
{
simple_lock(&vp->v_interlock);
if (vp->v_usecount) {
simple_unlock(&vp->v_interlock);
return;
}
if (simple_lock_try(&vnode_free_list_slock)) {
if (vp->v_freelist.tqe_prev != (struct vnode **)0xdeadb) {
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
simple_unlock(&vnode_free_list_slock);
}
simple_unlock(&vp->v_interlock);
}
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