freebsd-dev/sys/fs/unionfs/union_vfsops.c
Garrett Wollman 57bf258e3d Fix all areas of the system (or at least all those in LINT) to avoid storing
socket addresses in mbufs.  (Socket buffers are the one exception.)  A number
of kernel APIs needed to get fixed in order to make this happen.  Also,
fix three protocol families which kept PCBs in mbufs to not malloc them
instead.  Delete some old compatibility cruft while we're at it, and add
some new routines in the in_cksum family.
1997-08-16 19:16:27 +00:00

558 lines
14 KiB
C

/*
* Copyright (c) 1994, 1995 The Regents of the University of California.
* Copyright (c) 1994, 1995 Jan-Simon Pendry.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* @(#)union_vfsops.c 8.20 (Berkeley) 5/20/95
* $Id: union_vfsops.c,v 1.18 1997/08/02 14:32:29 bde Exp $
*/
/*
* Union Layer
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/filedesc.h>
#include <miscfs/union/union.h>
extern int union_init __P((struct vfsconf *));
extern int union_fhtovp __P((struct mount *mp, struct fid *fidp,
struct mbuf *nam, struct vnode **vpp,
int *exflagsp, struct ucred **credanonp));
extern int union_mount __P((struct mount *mp, char *path, caddr_t data,
struct nameidata *ndp, struct proc *p));
extern int union_quotactl __P((struct mount *mp, int cmd, uid_t uid,
caddr_t arg, struct proc *p));
extern int union_root __P((struct mount *mp, struct vnode **vpp));
extern int union_start __P((struct mount *mp, int flags, struct proc *p));
extern int union_statfs __P((struct mount *mp, struct statfs *sbp,
struct proc *p));
extern int union_sync __P((struct mount *mp, int waitfor,
struct ucred *cred, struct proc *p));
extern int union_unmount __P((struct mount *mp, int mntflags,
struct proc *p));
extern int union_vget __P((struct mount *mp, ino_t ino,
struct vnode **vpp));
extern int union_vptofh __P((struct vnode *vp, struct fid *fhp));
/*
* Mount union filesystem
*/
int
union_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
int error = 0;
struct union_args args;
struct vnode *lowerrootvp = NULLVP;
struct vnode *upperrootvp = NULLVP;
struct union_mount *um = 0;
struct ucred *cred = 0;
struct ucred *scred;
struct vattr va;
char *cp = 0;
int len;
u_int size;
int islowerunlocked = 0;
#ifdef UNION_DIAGNOSTIC
printf("union_mount(mp = %x)\n", mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE) {
/*
* Need to provide.
* 1. a way to convert between rdonly and rdwr mounts.
* 2. support for nfs exports.
*/
error = EOPNOTSUPP;
goto bad;
}
/*
* Get argument
*/
error = copyin(data, (caddr_t)&args, sizeof(struct union_args));
if (error)
goto bad;
lowerrootvp = mp->mnt_vnodecovered;
VREF(lowerrootvp);
/*
* Unlock lower node to avoid deadlock.
* (XXX) VOP_ISLOCKED is needed?
*/
if ((lowerrootvp->v_op == union_vnodeop_p) && VOP_ISLOCKED(lowerrootvp)) {
VOP_UNLOCK(lowerrootvp, 0, p);
islowerunlocked = 1;
}
/*
* Find upper node.
*/
NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT,
UIO_USERSPACE, args.target, p);
error = namei(ndp);
/*
* Re-lock vnode.
* (XXX) VOP_ISLOCKED is needed?
*/
if (islowerunlocked && !VOP_ISLOCKED(lowerrootvp))
vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, p);
if (error)
goto bad;
upperrootvp = ndp->ni_vp;
vrele(ndp->ni_dvp);
ndp->ni_dvp = NULL;
/*
* Check multi union mount to avoid `lock myself again' panic.
*/
if (upperrootvp == VTOUNION(lowerrootvp)->un_uppervp) {
#ifdef DIAGNOSTIC
printf("union_mount: multi union mount?\n");
#endif
error = EDEADLK;
goto bad;
}
if (upperrootvp->v_type != VDIR) {
error = EINVAL;
goto bad;
}
um = (struct union_mount *) malloc(sizeof(struct union_mount),
M_UFSMNT, M_WAITOK); /* XXX */
/*
* Keep a held reference to the target vnodes.
* They are vrele'd in union_unmount.
*
* Depending on the _BELOW flag, the filesystems are
* viewed in a different order. In effect, this is the
* same as providing a mount under option to the mount syscall.
*/
um->um_op = args.mntflags & UNMNT_OPMASK;
switch (um->um_op) {
case UNMNT_ABOVE:
um->um_lowervp = lowerrootvp;
um->um_uppervp = upperrootvp;
break;
case UNMNT_BELOW:
um->um_lowervp = upperrootvp;
um->um_uppervp = lowerrootvp;
break;
case UNMNT_REPLACE:
vrele(lowerrootvp);
lowerrootvp = NULLVP;
um->um_uppervp = upperrootvp;
um->um_lowervp = lowerrootvp;
break;
default:
error = EINVAL;
goto bad;
}
/*
* Unless the mount is readonly, ensure that the top layer
* supports whiteout operations
*/
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
error = VOP_WHITEOUT(um->um_uppervp, (struct componentname *) 0, LOOKUP);
if (error)
goto bad;
}
um->um_cred = p->p_ucred;
crhold(um->um_cred);
um->um_cmode = UN_DIRMODE &~ p->p_fd->fd_cmask;
/*
* Depending on what you think the MNT_LOCAL flag might mean,
* you may want the && to be || on the conditional below.
* At the moment it has been defined that the filesystem is
* only local if it is all local, ie the MNT_LOCAL flag implies
* that the entire namespace is local. If you think the MNT_LOCAL
* flag implies that some of the files might be stored locally
* then you will want to change the conditional.
*/
if (um->um_op == UNMNT_ABOVE) {
if (((um->um_lowervp == NULLVP) ||
(um->um_lowervp->v_mount->mnt_flag & MNT_LOCAL)) &&
(um->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
mp->mnt_flag |= MNT_LOCAL;
}
/*
* Copy in the upper layer's RDONLY flag. This is for the benefit
* of lookup() which explicitly checks the flag, rather than asking
* the filesystem for it's own opinion. This means, that an update
* mount of the underlying filesystem to go from rdonly to rdwr
* will leave the unioned view as read-only.
*/
mp->mnt_flag |= (um->um_uppervp->v_mount->mnt_flag & MNT_RDONLY);
mp->mnt_data = (qaddr_t) um;
vfs_getnewfsid(mp);
(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
switch (um->um_op) {
case UNMNT_ABOVE:
cp = "<above>:";
break;
case UNMNT_BELOW:
cp = "<below>:";
break;
case UNMNT_REPLACE:
cp = "";
break;
}
len = strlen(cp);
bcopy(cp, mp->mnt_stat.f_mntfromname, len);
cp = mp->mnt_stat.f_mntfromname + len;
len = MNAMELEN - len;
(void) copyinstr(args.target, cp, len - 1, &size);
bzero(cp + size, len - size);
(void)union_statfs(mp, &mp->mnt_stat, p);
#ifdef UNION_DIAGNOSTIC
printf("union_mount: from %s, on %s\n",
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
#endif
return (0);
bad:
if (um)
free(um, M_UFSMNT);
if (cred)
crfree(cred);
if (upperrootvp)
vrele(upperrootvp);
if (lowerrootvp)
vrele(lowerrootvp);
return (error);
}
/*
* VFS start. Nothing needed here - the start routine
* on the underlying filesystem(s) will have been called
* when that filesystem was mounted.
*/
int
union_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
}
/*
* Free reference to union layer
*/
int
union_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
struct vnode *um_rootvp;
int error;
int freeing;
int flags = 0;
#ifdef UNION_DIAGNOSTIC
printf("union_unmount(mp = %x)\n", mp);
#endif
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
if (error = union_root(mp, &um_rootvp))
return (error);
/*
* Keep flushing vnodes from the mount list.
* This is needed because of the un_pvp held
* reference to the parent vnode.
* If more vnodes have been freed on a given pass,
* the try again. The loop will iterate at most
* (d) times, where (d) is the maximum tree depth
* in the filesystem.
*/
for (freeing = 0; vflush(mp, um_rootvp, flags) != 0;) {
struct vnode *vp;
int n;
/* count #vnodes held on mount list */
for (n = 0, vp = mp->mnt_vnodelist.lh_first;
vp != NULLVP;
vp = vp->v_mntvnodes.le_next)
n++;
/* if this is unchanged then stop */
if (n == freeing)
break;
/* otherwise try once more time */
freeing = n;
}
/* At this point the root vnode should have a single reference */
if (um_rootvp->v_usecount > 1) {
vput(um_rootvp);
return (EBUSY);
}
#ifdef UNION_DIAGNOSTIC
vprint("union root", um_rootvp);
#endif
/*
* Discard references to upper and lower target vnodes.
*/
if (um->um_lowervp)
vrele(um->um_lowervp);
vrele(um->um_uppervp);
crfree(um->um_cred);
/*
* Release reference on underlying root vnode
*/
vput(um_rootvp);
/*
* And blow it away for future re-use
*/
vgone(um_rootvp);
/*
* Finally, throw away the union_mount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return (0);
}
int
union_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct proc *p = curproc; /* XXX */
struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
int error;
int loselock;
/*
* Return locked reference to root.
*/
VREF(um->um_uppervp);
if ((um->um_op == UNMNT_BELOW) &&
VOP_ISLOCKED(um->um_uppervp)) {
loselock = 1;
} else {
if (VOP_ISLOCKED(um->um_uppervp)) {
/*
* XXX
* Should we check type of node?
*/
#ifdef DIAGNOSTIC
printf("union_root: multi union mount?");
#endif
vrele(um->um_uppervp);
return EDEADLK;
} else
vn_lock(um->um_uppervp, LK_EXCLUSIVE | LK_RETRY, p);
loselock = 0;
}
if (um->um_lowervp)
VREF(um->um_lowervp);
error = union_allocvp(vpp, mp,
(struct vnode *) 0,
(struct vnode *) 0,
(struct componentname *) 0,
um->um_uppervp,
um->um_lowervp,
1);
if (error) {
if (loselock)
vrele(um->um_uppervp);
else
vput(um->um_uppervp);
if (um->um_lowervp)
vrele(um->um_lowervp);
} else {
if (loselock)
VTOUNION(*vpp)->un_flags &= ~UN_ULOCK;
}
return (error);
}
int
union_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
int error;
struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
struct statfs mstat;
int lbsize;
#ifdef UNION_DIAGNOSTIC
printf("union_statfs(mp = %x, lvp = %x, uvp = %x)\n", mp,
um->um_lowervp,
um->um_uppervp);
#endif
bzero(&mstat, sizeof(mstat));
if (um->um_lowervp) {
error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p);
if (error)
return (error);
}
/* now copy across the "interesting" information and fake the rest */
#if 0
sbp->f_type = mstat.f_type;
sbp->f_flags = mstat.f_flags;
sbp->f_bsize = mstat.f_bsize;
sbp->f_iosize = mstat.f_iosize;
#endif
lbsize = mstat.f_bsize;
sbp->f_blocks = mstat.f_blocks;
sbp->f_bfree = mstat.f_bfree;
sbp->f_bavail = mstat.f_bavail;
sbp->f_files = mstat.f_files;
sbp->f_ffree = mstat.f_ffree;
error = VFS_STATFS(um->um_uppervp->v_mount, &mstat, p);
if (error)
return (error);
sbp->f_flags = mstat.f_flags;
sbp->f_bsize = mstat.f_bsize;
sbp->f_iosize = mstat.f_iosize;
/*
* if the lower and upper blocksizes differ, then frig the
* block counts so that the sizes reported by df make some
* kind of sense. none of this makes sense though.
*/
if (mstat.f_bsize != lbsize)
sbp->f_blocks = ((off_t) sbp->f_blocks * lbsize) / mstat.f_bsize;
/*
* The "total" fields count total resources in all layers,
* the "free" fields count only those resources which are
* free in the upper layer (since only the upper layer
* is writeable).
*/
sbp->f_blocks += mstat.f_blocks;
sbp->f_bfree = mstat.f_bfree;
sbp->f_bavail = mstat.f_bavail;
sbp->f_files += mstat.f_files;
sbp->f_ffree = mstat.f_ffree;
if (sbp != &mp->mnt_stat) {
sbp->f_type = mp->mnt_vfc->vfc_typenum;
bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
}
return (0);
}
/*
* XXX - Assumes no data cached at union layer.
*/
#define union_sync ((int (*) __P((struct mount *, int, struct ucred *, \
struct proc *)))nullop)
#define union_fhtovp ((int (*) __P((struct mount *, struct fid *, \
struct sockaddr *, struct vnode **, int *, struct ucred **)))eopnotsupp)
#define union_quotactl ((int (*) __P((struct mount *, int, uid_t, caddr_t, \
struct proc *)))eopnotsupp)
#define union_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \
size_t, struct proc *)))eopnotsupp)
#define union_vget ((int (*) __P((struct mount *, ino_t, struct vnode **))) \
eopnotsupp)
#define union_vptofh ((int (*) __P((struct vnode *, struct fid *)))eopnotsupp)
struct vfsops union_vfsops = {
union_mount,
union_start,
union_unmount,
union_root,
union_quotactl,
union_statfs,
union_sync,
union_vget,
union_fhtovp,
union_vptofh,
union_init,
};
VFS_SET(union_vfsops, union, MOUNT_UNION, VFCF_LOOPBACK);