[unix-history] / usr / src / sys / miscfs / nullfs / null_vfsops.c

/*
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)null_vfsops.c	8.2 (Berkeley) %G%
 *
 * @(#)lofs_vfsops.c	1.2 (Berkeley) 6/18/92
 * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
 */

/*
 * Null Layer
 * (See null_vnops.c for a description of what this does.)
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/nullfs/null.h>

/*
 * Mount null layer
 */
int
nullfs_mount(mp, path, data, ndp, p)
	struct mount *mp;
	char *path;
	caddr_t data;
	struct nameidata *ndp;
	struct proc *p;
{
	int error = 0;
	struct null_args args;
	struct vnode *lowerrootvp, *vp;
	struct vnode *nullm_rootvp;
	struct null_mount *xmp;
	u_int size;

#ifdef NULLFS_DIAGNOSTIC
	printf("nullfs_mount(mp = %x)\n", mp);
#endif

	/*
	 * Update is a no-op
	 */
	if (mp->mnt_flag & MNT_UPDATE) {
		return (EOPNOTSUPP);
		/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
	}

	/*
	 * Get argument
	 */
	if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
		return (error);

	/*
	 * Find lower node
	 */
	NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
		UIO_USERSPACE, args.target, p);
	if (error = namei(ndp))
		return (error);

	/*
	 * Sanity check on lower vnode
	 */
	lowerrootvp = ndp->ni_vp;

	vrele(ndp->ni_dvp);
	ndp->ni_dvp = NULL;

	xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
				M_UFSMNT, M_WAITOK);	/* XXX */

	/*
	 * Save reference to underlying FS
	 */
	xmp->nullm_vfs = lowerrootvp->v_mount;

	/*
	 * Save reference.  Each mount also holds
	 * a reference on the root vnode.
	 */
	error = null_node_create(mp, lowerrootvp, &vp);
	/*
	 * Unlock the node (either the lower or the alias)
	 */
	VOP_UNLOCK(vp);
	/*
	 * Make sure the node alias worked
	 */
	if (error) {
		vrele(lowerrootvp);
		free(xmp, M_UFSMNT);	/* XXX */
		return (error);
	}

	/*
	 * Keep a held reference to the root vnode.
	 * It is vrele'd in nullfs_unmount.
	 */
	nullm_rootvp = vp;
	nullm_rootvp->v_flag |= VROOT;
	xmp->nullm_rootvp = nullm_rootvp;
	if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
		mp->mnt_flag |= MNT_LOCAL;
	mp->mnt_data = (qaddr_t) xmp;
	getnewfsid(mp, MOUNT_LOFS);

	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 
	    &size);
	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
#ifdef NULLFS_DIAGNOSTIC
	printf("nullfs_mount: lower %s, alias at %s\n",
		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
#endif
	return (0);
}

/*
 * VFS start.  Nothing needed here - the start routine
 * on the underlying filesystem will have been called
 * when that filesystem was mounted.
 */
int
nullfs_start(mp, flags, p)
	struct mount *mp;
	int flags;
	struct proc *p;
{
	return (0);
	/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
}

/*
 * Free reference to null layer
 */
int
nullfs_unmount(mp, mntflags, p)
	struct mount *mp;
	int mntflags;
	struct proc *p;
{
	struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
	int error;
	int flags = 0;
	extern int doforce;

#ifdef NULLFS_DIAGNOSTIC
	printf("nullfs_unmount(mp = %x)\n", mp);
#endif

	if (mntflags & MNT_FORCE) {
		/* lofs can never be rootfs so don't check for it */
		if (!doforce)
			return (EINVAL);
		flags |= FORCECLOSE;
	}

	/*
	 * Clear out buffer cache.  I don't think we
	 * ever get anything cached at this level at the
	 * moment, but who knows...
	 */
#if 0
	mntflushbuf(mp, 0); 
	if (mntinvalbuf(mp, 1))
		return (EBUSY);
#endif
	if (nullm_rootvp->v_usecount > 1)
		return (EBUSY);
	if (error = vflush(mp, nullm_rootvp, flags))
		return (error);

#ifdef NULLFS_DIAGNOSTIC
	vprint("alias root of lower", nullm_rootvp);
#endif	 
	/*
	 * Release reference on underlying root vnode
	 */
	vrele(nullm_rootvp);
	/*
	 * And blow it away for future re-use
	 */
	vgone(nullm_rootvp);
	/*
	 * Finally, throw away the null_mount structure
	 */
	free(mp->mnt_data, M_UFSMNT);	/* XXX */
	mp->mnt_data = 0;
	return 0;
}

int
nullfs_root(mp, vpp)
	struct mount *mp;
	struct vnode **vpp;
{
	struct vnode *vp;

#ifdef NULLFS_DIAGNOSTIC
	printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
			MOUNTTONULLMOUNT(mp)->nullm_rootvp,
			NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
			);
#endif

	/*
	 * Return locked reference to root.
	 */
	vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
	VREF(vp);
	VOP_LOCK(vp);
	*vpp = vp;
	return 0;
}

int
nullfs_quotactl(mp, cmd, uid, arg, p)
	struct mount *mp;
	int cmd;
	uid_t uid;
	caddr_t arg;
	struct proc *p;
{
	return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
}

int
nullfs_statfs(mp, sbp, p)
	struct mount *mp;
	struct statfs *sbp;
	struct proc *p;
{
	int error;
	struct statfs mstat;

#ifdef NULLFS_DIAGNOSTIC
	printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
			MOUNTTONULLMOUNT(mp)->nullm_rootvp,
			NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
			);
#endif

	bzero(&mstat, sizeof(mstat));

	error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
	if (error)
		return (error);

	/* now copy across the "interesting" information and fake the rest */
	sbp->f_type = mstat.f_type;
	sbp->f_flags = mstat.f_flags;
	sbp->f_bsize = mstat.f_bsize;
	sbp->f_iosize = mstat.f_iosize;
	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) {
		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);
}

int
nullfs_sync(mp, waitfor, cred, p)
	struct mount *mp;
	int waitfor;
	struct ucred *cred;
	struct proc *p;
{
	/*
	 * XXX - Assumes no data cached at null layer.
	 */
	return (0);
}

int
nullfs_vget(mp, ino, vpp)
	struct mount *mp;
	ino_t ino;
	struct vnode **vpp;
{
	
	return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
}

int
nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
	struct mount *mp;
	struct fid *fidp;
	struct mbuf *nam;
	struct vnode **vpp;
	int *exflagsp;
	struct ucred**credanonp;
{

	return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
}

int
nullfs_vptofh(vp, fhp)
	struct vnode *vp;
	struct fid *fhp;
{
	return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
}

int nullfs_init __P((void));

struct vfsops null_vfsops = {
	nullfs_mount,
	nullfs_start,
	nullfs_unmount,
	nullfs_root,
	nullfs_quotactl,
	nullfs_statfs,
	nullfs_sync,
	nullfs_vget,
	nullfs_fhtovp,
	nullfs_vptofh,
	nullfs_init,
};
Commit	Line	Data
32a01b17	1	/*
1446b03c KB	2	* Copyright (c) 1992, 1993
1446b03c KB	3	* The Regents of the University of California. All rights reserved.
32a01b17 JH	4	*
	5	* This code is derived from software donated to Berkeley by
	6	* Jan-Simon Pendry.
	7	*
	8	* %sccs.include.redist.c%
	9	*
1611db1e	10	* @(#)null_vfsops.c 8.2 (Berkeley) %G%
32a01b17	11	*
11cda5c1 JH	12	* @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
11cda5c1 JH	13	* $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
32a01b17 JH	14	*/
	15
	16	/*
11cda5c1 JH	17	* Null Layer
11cda5c1 JH	18	* (See null_vnops.c for a description of what this does.)
32a01b17 JH	19	*/
	20
	21	#include <sys/param.h>
	22	#include <sys/systm.h>
	23	#include <sys/time.h>
	24	#include <sys/types.h>
	25	#include <sys/vnode.h>
	26	#include <sys/mount.h>
	27	#include <sys/namei.h>
	28	#include <sys/malloc.h>
3fa2b388	29	#include <miscfs/nullfs/null.h>
32a01b17 JH	30
32a01b17 JH	31	/*
11cda5c1	32	* Mount null layer
32a01b17	33	*/
c8b2716f	34	int
d2943a3d	35	nullfs_mount(mp, path, data, ndp, p)
32a01b17 JH	36	struct mount *mp;
	37	char *path;
	38	caddr_t data;
	39	struct nameidata *ndp;
	40	struct proc *p;
	41	{
32a01b17	42	int error = 0;
d2943a3d	43	struct null_args args;
11cda5c1	44	struct vnode lowerrootvp, vp;
d2943a3d	45	struct vnode *nullm_rootvp;
7936eee0	46	struct null_mount *xmp;
32a01b17 JH	47	u_int size;
32a01b17 JH	48
d2943a3d JH	49	#ifdef NULLFS_DIAGNOSTIC
d2943a3d JH	50	printf("nullfs_mount(mp = %x)\n", mp);
32a01b17 JH	51	#endif
	52
	53	/*
	54	* Update is a no-op
	55	*/
	56	if (mp->mnt_flag & MNT_UPDATE) {
	57	return (EOPNOTSUPP);
d2943a3d	58	/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
32a01b17 JH	59	}
	60
	61	/*
	62	* Get argument
	63	*/
d2943a3d	64	if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
32a01b17 JH	65	return (error);
	66
	67	/*
30969417	68	* Find lower node
32a01b17 JH	69	*/
	70	NDINIT(ndp, LOOKUP, FOLLOW\|WANTPARENT\|LOCKLEAF,
	71	UIO_USERSPACE, args.target, p);
	72	if (error = namei(ndp))
	73	return (error);
	74
	75	/*
30969417	76	* Sanity check on lower vnode
32a01b17	77	*/
11cda5c1	78	lowerrootvp = ndp->ni_vp;
32a01b17	79
7936eee0 JH	80	vrele(ndp->ni_dvp);
7936eee0 JH	81	ndp->ni_dvp = NULL;
32a01b17	82
7936eee0	83	xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
32a01b17 JH	84	M_UFSMNT, M_WAITOK); /* XXX */
	85
	86	/*
7936eee0	87	* Save reference to underlying FS
32a01b17	88	*/
7936eee0	89	xmp->nullm_vfs = lowerrootvp->v_mount;
32a01b17 JH	90
	91	/*
	92	* Save reference. Each mount also holds
	93	* a reference on the root vnode.
	94	*/
c8b2716f	95	error = null_node_create(mp, lowerrootvp, &vp);
32a01b17	96	/*
30969417	97	* Unlock the node (either the lower or the alias)
32a01b17 JH	98	*/
	99	VOP_UNLOCK(vp);
	100	/*
	101	* Make sure the node alias worked
	102	*/
	103	if (error) {
11cda5c1	104	vrele(lowerrootvp);
7936eee0	105	free(xmp, M_UFSMNT); /* XXX */
32a01b17 JH	106	return (error);
	107	}
	108
	109	/*
	110	* Keep a held reference to the root vnode.
d2943a3d	111	* It is vrele'd in nullfs_unmount.
32a01b17	112	*/
d2943a3d JH	113	nullm_rootvp = vp;
d2943a3d JH	114	nullm_rootvp->v_flag \|= VROOT;
7936eee0	115	xmp->nullm_rootvp = nullm_rootvp;
c8b2716f	116	if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
32a01b17	117	mp->mnt_flag \|= MNT_LOCAL;
7936eee0	118	mp->mnt_data = (qaddr_t) xmp;
32a01b17 JH	119	getnewfsid(mp, MOUNT_LOFS);
	120
	121	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
	122	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
	123	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
	124	&size);
	125	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
d2943a3d	126	#ifdef NULLFS_DIAGNOSTIC
30969417	127	printf("nullfs_mount: lower %s, alias at %s\n",
32a01b17 JH	128	mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
	129	#endif
	130	return (0);
	131	}
	132
	133	/*
	134	* VFS start. Nothing needed here - the start routine
	135	* on the underlying filesystem will have been called
	136	* when that filesystem was mounted.
	137	*/
c8b2716f	138	int
d2943a3d	139	nullfs_start(mp, flags, p)
32a01b17 JH	140	struct mount *mp;
	141	int flags;
	142	struct proc *p;
	143	{
	144	return (0);
d2943a3d	145	/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
32a01b17 JH	146	}
	147
	148	/*
11cda5c1	149	* Free reference to null layer
32a01b17	150	*/
c8b2716f	151	int
d2943a3d	152	nullfs_unmount(mp, mntflags, p)
32a01b17 JH	153	struct mount *mp;
	154	int mntflags;
	155	struct proc *p;
	156	{
d2943a3d	157	struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
32a01b17 JH	158	int error;
	159	int flags = 0;
	160	extern int doforce;
	161
d2943a3d JH	162	#ifdef NULLFS_DIAGNOSTIC
d2943a3d JH	163	printf("nullfs_unmount(mp = %x)\n", mp);
32a01b17 JH	164	#endif
	165
	166	if (mntflags & MNT_FORCE) {
	167	/* lofs can never be rootfs so don't check for it */
	168	if (!doforce)
	169	return (EINVAL);
	170	flags \|= FORCECLOSE;
	171	}
	172
	173	/*
	174	* Clear out buffer cache. I don't think we
	175	* ever get anything cached at this level at the
	176	* moment, but who knows...
	177	*/
c8b2716f	178	#if 0
32a01b17 JH	179	mntflushbuf(mp, 0);
	180	if (mntinvalbuf(mp, 1))
	181	return (EBUSY);
c8b2716f	182	#endif
d2943a3d	183	if (nullm_rootvp->v_usecount > 1)
32a01b17	184	return (EBUSY);
d2943a3d	185	if (error = vflush(mp, nullm_rootvp, flags))
32a01b17 JH	186	return (error);
32a01b17 JH	187
d2943a3d	188	#ifdef NULLFS_DIAGNOSTIC
30969417	189	vprint("alias root of lower", nullm_rootvp);
32a01b17 JH	190	#endif
	191	/*
	192	* Release reference on underlying root vnode
	193	*/
d2943a3d	194	vrele(nullm_rootvp);
32a01b17 JH	195	/*
	196	* And blow it away for future re-use
	197	*/
d2943a3d	198	vgone(nullm_rootvp);
32a01b17	199	/*
d2943a3d	200	* Finally, throw away the null_mount structure
32a01b17 JH	201	*/
	202	free(mp->mnt_data, M_UFSMNT); /* XXX */
	203	mp->mnt_data = 0;
	204	return 0;
	205	}
	206
c8b2716f	207	int
d2943a3d	208	nullfs_root(mp, vpp)
32a01b17 JH	209	struct mount *mp;
	210	struct vnode **vpp;
	211	{
32a01b17 JH	212	struct vnode *vp;
32a01b17 JH	213
d2943a3d JH	214	#ifdef NULLFS_DIAGNOSTIC
	215	printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
	216	MOUNTTONULLMOUNT(mp)->nullm_rootvp,
c8b2716f	217	NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
32a01b17 JH	218	);
	219	#endif
	220
	221	/*
	222	* Return locked reference to root.
	223	*/
d2943a3d	224	vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
32a01b17 JH	225	VREF(vp);
	226	VOP_LOCK(vp);
	227	*vpp = vp;
	228	return 0;
	229	}
	230
c8b2716f	231	int
d2943a3d	232	nullfs_quotactl(mp, cmd, uid, arg, p)
32a01b17 JH	233	struct mount *mp;
	234	int cmd;
	235	uid_t uid;
	236	caddr_t arg;
	237	struct proc *p;
	238	{
d2943a3d	239	return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
32a01b17 JH	240	}
32a01b17 JH	241
c8b2716f	242	int
d2943a3d	243	nullfs_statfs(mp, sbp, p)
32a01b17 JH	244	struct mount *mp;
	245	struct statfs *sbp;
	246	struct proc *p;
	247	{
	248	int error;
	249	struct statfs mstat;
	250
d2943a3d JH	251	#ifdef NULLFS_DIAGNOSTIC
	252	printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
	253	MOUNTTONULLMOUNT(mp)->nullm_rootvp,
c8b2716f	254	NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
32a01b17 JH	255	);
	256	#endif
	257
	258	bzero(&mstat, sizeof(mstat));
	259
d2943a3d	260	error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
32a01b17 JH	261	if (error)
	262	return (error);
	263
	264	/* now copy across the "interesting" information and fake the rest */
	265	sbp->f_type = mstat.f_type;
	266	sbp->f_flags = mstat.f_flags;
	267	sbp->f_bsize = mstat.f_bsize;
	268	sbp->f_iosize = mstat.f_iosize;
	269	sbp->f_blocks = mstat.f_blocks;
	270	sbp->f_bfree = mstat.f_bfree;
	271	sbp->f_bavail = mstat.f_bavail;
	272	sbp->f_files = mstat.f_files;
	273	sbp->f_ffree = mstat.f_ffree;
	274	if (sbp != &mp->mnt_stat) {
	275	bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
	276	bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
	277	bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
	278	}
	279	return (0);
	280	}
	281
c8b2716f JH	282	int
	283	nullfs_sync(mp, waitfor, cred, p)
	284	struct mount *mp;
	285	int waitfor;
	286	struct ucred *cred;
	287	struct proc *p;
32a01b17	288	{
11cda5c1	289	/*
c8b2716f	290	* XXX - Assumes no data cached at null layer.
11cda5c1	291	*/
32a01b17 JH	292	return (0);
	293	}
	294
c8b2716f JH	295	int
c8b2716f JH	296	nullfs_vget(mp, ino, vpp)
32a01b17	297	struct mount *mp;
c8b2716f JH	298	ino_t ino;
	299	struct vnode **vpp;
	300	{
	301
	302	return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
	303	}
	304
	305	int
	306	nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
	307	struct mount *mp;
	308	struct fid *fidp;
	309	struct mbuf *nam;
32a01b17	310	struct vnode **vpp;
c8b2716f JH	311	int *exflagsp;
c8b2716f JH	312	struct ucred**credanonp;
32a01b17	313	{
c8b2716f JH	314
c8b2716f JH	315	return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
32a01b17 JH	316	}
32a01b17 JH	317
c8b2716f	318	int
d2943a3d	319	nullfs_vptofh(vp, fhp)
32a01b17 JH	320	struct vnode *vp;
	321	struct fid *fhp;
	322	{
c8b2716f	323	return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
32a01b17 JH	324	}
32a01b17 JH	325
d2943a3d JH	326	int nullfs_init __P((void));
	327
	328	struct vfsops null_vfsops = {
	329	nullfs_mount,
	330	nullfs_start,
	331	nullfs_unmount,
	332	nullfs_root,
	333	nullfs_quotactl,
	334	nullfs_statfs,
	335	nullfs_sync,
c8b2716f	336	nullfs_vget,
d2943a3d JH	337	nullfs_fhtovp,
	338	nullfs_vptofh,
	339	nullfs_init,
32a01b17	340	};