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freebsd-nq/sys/kern/vfs_subr.c
John Dyson 23be6be853 Fix a problem with the vfs vnode caching that it doesn't grow quickly 
enough and can cause some strange performance problems.  Specifically, at
or near startup time is when the problem is worst.  To reproduce
the problem, run "lat_syscall stat" from the alpha lmbench code right
after bootup.  A positive side effect of this mod is that the name
cache can be set to grow again by sysctl.  A noticable positive
performance impact is realized due to a larger namecache being available
as needed (or tuned.)
1997-08-04 07:43:28 +00:00

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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
* $Id: vfs_subr.c,v 1.89 1997/07/17 07:17:31 dfr 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 <sys/dirent.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;
struct nfs_public nfs_pub; /* publicly exported FS */
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);
if (freevnodes >= desiredvnodes) {
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;
}
}
} else {
vp = NULL;
}
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 ||
(vp->v_object->flags & OBJ_DEAD))) {
/*
* 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) ||
(vp->v_object->flags & OBJ_DEAD))) {
/*
* 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;
}
/*
* 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, irefed;
vm_object_t object;
/*
* 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);
object = vp->v_object;
irefed = 0;
if (object && ((object->flags & OBJ_DEAD) == 0)) {
if (object->ref_count == 0) {
vm_object_reference(object);
irefed = 1;
}
++object->ref_count;
pager_cache(object, FALSE);
}
/*
* Clean out any buffers associated with the vnode.
*/
if (flags & DOCLOSE)
vinvalbuf(vp, V_SAVE, NOCRED, p, 0, 0);
if (irefed) {
vm_object_deallocate(object);
}
/*
* 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);
}
/*
* XXX
* Exporting the vnode list on large systems causes them to crash.
* Exporting the vnode list on medium systems causes sysctl to coredump.
*/
#if 0
SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
0, 0, sysctl_vnode, "S,vnode", "");
#endif
/*
* Check to see if a filesystem is mounted on a block device.
*/
int
vfs_mountedon(vp)
struct vnode *vp;
{
struct vnode *vq;
int error = 0;
if (vp->v_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) {
if (mp->mnt_flag & MNT_EXPUBLIC) {
vfs_setpublicfs(NULL, NULL, NULL);
mp->mnt_flag &= ~MNT_EXPUBLIC;
}
vfs_free_addrlist(nep);
mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
}
if (argp->ex_flags & MNT_EXPORTED) {
if (argp->ex_flags & MNT_EXPUBLIC) {
if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
return (error);
mp->mnt_flag |= MNT_EXPUBLIC;
}
if ((error = vfs_hang_addrlist(mp, nep, argp)))
return (error);
mp->mnt_flag |= MNT_EXPORTED;
}
return (0);
}
/*
* Set the publicly exported filesystem (WebNFS). Currently, only
* one public filesystem is possible in the spec (RFC 2054 and 2055)
*/
int
vfs_setpublicfs(mp, nep, argp)
struct mount *mp;
struct netexport *nep;
struct export_args *argp;
{
int error;
struct vnode *rvp;
char *cp;
/*
* mp == NULL -> invalidate the current info, the FS is
* no longer exported. May be called from either vfs_export
* or unmount, so check if it hasn't already been done.
*/
if (mp == NULL) {
if (nfs_pub.np_valid) {
nfs_pub.np_valid = 0;
if (nfs_pub.np_index != NULL) {
FREE(nfs_pub.np_index, M_TEMP);
nfs_pub.np_index = NULL;
}
}
return (0);
}
/*
* Only one allowed at a time.
*/
if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
return (EBUSY);
/*
* Get real filehandle for root of exported FS.
*/
bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
if ((error = VFS_ROOT(mp, &rvp)))
return (error);
if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
return (error);
vput(rvp);
/*
* If an indexfile was specified, pull it in.
*/
if (argp->ex_indexfile != NULL) {
MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
M_WAITOK);
error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
MAXNAMLEN, (size_t *)0);
if (!error) {
/*
* Check for illegal filenames.
*/
for (cp = nfs_pub.np_index; *cp; cp++) {
if (*cp == '/') {
error = EINVAL;
break;
}
}
}
if (error) {
FREE(nfs_pub.np_index, M_TEMP);
return (error);
}
}
nfs_pub.np_mount = mp;
nfs_pub.np_valid = 1;
return (0);
}
struct netcred *
vfs_export_lookup(mp, nep, nam)
register struct mount *mp;
struct netexport *nep;
struct 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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