[unix-history] / usr / src / sys / miscfs / umapfs / umap_subr.c

/*
 * Copyright (c) 1992 The Regents of the University of California
 * Copyright (c) 1990, 1992 Jan-Simon Pendry
 * All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)lofs_subr.c	1.2 (Berkeley) 6/18/92
 *
 * $Id: lofs_subr.c,v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
 */

#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 <umapfs/umap.h>

#define LOG2_SIZEVNODE 7		/* log2(sizeof struct vnode) */
#define	NUMAPNODECACHE 16
#define	UMAP_NHASH(vp) ((((u_long)vp)>>LOG2_SIZEVNODE) & (NUMAPNODECACHE-1))

/*
 * Null layer cache:
 * Each cache entry holds a reference to the target vnode
 * along with a pointer to the alias vnode.  When an
 * entry is added the target vnode is VREF'd.  When the
 * alias is removed the target vnode is vrele'd.
 */

/*
 * Cache head
 */
struct umap_node_cache {
	struct umap_node	*ac_forw;
	struct umap_node	*ac_back;
};

static struct umap_node_cache umap_node_cache[NUMAPNODECACHE];

/*
 * Initialise cache headers
 */
umapfs_init()
{
	struct umap_node_cache *ac;
#ifdef UMAPFS_DIAGNOSTIC
	printf("umapfs_init\n");		/* printed during system boot */
#endif

	for (ac = umap_node_cache; ac < umap_node_cache + NUMAPNODECACHE; ac++)
		ac->ac_forw = ac->ac_back = (struct umap_node *) ac;
}

/*
 * Compute hash list for given target vnode
 */
static struct umap_node_cache *
umap_node_hash(targetvp)
struct vnode *targetvp;
{
	return (&umap_node_cache[UMAP_NHASH(targetvp)]);
}

/*
 * Return alias for target vnode if already exists, else 0.
 */
static struct vnode *
umap_node_find(mp, targetvp)
	struct mount *mp;
	struct vnode *targetvp;
{
	struct umap_node_cache *hd;
	struct umap_node *a;
	struct vnode *vp;

#ifdef UMAPFS_DIAGNOSTIC
	printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
#endif

	/*
	 * Find hash base, and then search the (two-way) linked
	 * list looking for a umap_node structure which is referencing
	 * the target vnode.  If found, the increment the umap_node
	 * reference count (but NOT the target vnode's VREF counter).
	 */
	hd = umap_node_hash(targetvp);

 loop:
	for (a = hd->ac_forw; a != (struct umap_node *) hd; a = a->umap_forw) {
		if (a->umap_lowervp == targetvp && a->umap_vnode->v_mount == mp) {
			vp = UMAPTOV(a);
			/*
			 * We need vget for the VXLOCK
			 * stuff, but we don't want to lock
			 * the lower node.
			 */
			if (vget_nolock(vp)) {
				printf ("null_node_find: vget failed.\n");
				goto loop;
			};
			return (vp);
		}
	}

#ifdef UMAPFS_DIAGNOSTIC
	printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
#endif

	return (0);
}

/*
 * Make a new umap_node node.
 * Vp is the alias vnode, lofsvp is the target vnode.
 * Maintain a reference to (targetvp).
 */
static int
umap_node_alloc(mp, lowervp, vpp)
	struct mount *mp;
	struct vnode *lowervp;
	struct vnode **vpp;
{
	struct umap_node_cache *hd;
	struct umap_node *xp;
	struct vnode *othervp, *vp;
	int error;

	if (error = getnewvnode(VT_UFS, mp, umap_vnodeop_p, vpp))
		return (error);	/* XXX: VT_UMAP above */
	vp = *vpp;

	MALLOC(xp, struct umap_node *, sizeof(struct umap_node), M_TEMP, M_WAITOK);
	vp->v_type = lowervp->v_type;
	xp->umap_vnode = vp;
	vp->v_data = xp;
	xp->umap_lowervp = lowervp;
	/*
	 * Before we insert our new node onto the hash chains,
	 * check to see if someone else has beaten us to it.
	 * (We could have slept in MALLOC.)
	 */
	if (othervp = umap_node_find(lowervp)) {
		FREE(xp, M_TEMP);
		vp->v_type = VBAD;	/* node is discarded */
		vp->v_usecount = 0;	/* XXX */
		*vpp = othervp;
		return 0;
	};
	VREF(lowervp);   /* Extra VREF will be vrele'd in umap_node_create */
	hd = umap_node_hash(lowervp);
	insque(xp, hd);
	return 0;
}


/*
 * Try to find an existing umap_node vnode refering
 * to it, otherwise make a new umap_node vnode which
 * contains a reference to the target vnode.
 */
int
umap_node_create(mp, targetvp, newvpp)
	struct mount *mp;
	struct vnode *targetvp;
	struct vnode **newvpp;
{
	struct vnode *aliasvp;

	if (aliasvp = umap_node_find(mp, targetvp)) {
		/*
		 * Take another reference to the alias vnode
		 */
#ifdef UMAPFS_DIAGNOSTIC
		vprint("umap_node_create: exists", ap->umap_vnode);
#endif
		/* VREF(aliasvp); */
	} else {
		int error;

		/*
		 * Get new vnode.
		 */
#ifdef UMAPFS_DIAGNOSTIC
		printf("umap_node_create: create new alias vnode\n");
#endif
		/*
		 * Make new vnode reference the umap_node.
		 */
		if (error = umap_node_alloc(mp, targetvp, &aliasvp))
			return error;

		/*
		 * aliasvp is already VREF'd by getnewvnode()
		 */
	}

	vrele(targetvp);

#ifdef UMAPFS_DIAGNOSTIC
	vprint("umap_node_create: alias", aliasvp);
	vprint("umap_node_create: target", targetvp);
#endif

	*newvpp = aliasvp;
	return (0);
}
#ifdef UMAPFS_DIAGNOSTIC
int umap_checkvp_barrier = 1;
struct vnode *
umap_checkvp(vp, fil, lno)
	struct vnode *vp;
	char *fil;
	int lno;
{
	struct umap_node *a = VTOUMAP(vp);
#if 0
	/*
	 * Can't do this check because vop_reclaim runs
	 * with funny vop vector.
	 */
	if (vp->v_op != umap_vnodeop_p) {
		printf ("umap_checkvp: on non-umap-node\n");
		while (umap_checkvp_barrier) /*WAIT*/ ;
		panic("umap_checkvp");
	};
#endif
	if (a->umap_lowervp == NULL) {
		/* Should never happen */
		int i; u_long *p;
		printf("vp = %x, ZERO ptr\n", vp);
		for (p = (u_long *) a, i = 0; i < 8; i++)
			printf(" %x", p[i]);
		printf("\n");
		/* wait for debugger */
		while (umap_checkvp_barrier) /*WAIT*/ ;
		panic("umap_checkvp");
	}
	if (a->umap_lowervp->v_usecount < 1) {
		int i; u_long *p;
		printf("vp = %x, unref'ed lowervp\n", vp);
		for (p = (u_long *) a, i = 0; i < 8; i++)
			printf(" %x", p[i]);
		printf("\n");
		/* wait for debugger */
		while (umap_checkvp_barrier) /*WAIT*/ ;
		panic ("umap with unref'ed lowervp");
	};
#if 0
	printf("umap %x/%d -> %x/%d [%s, %d]\n",
	        a->umap_vnode, a->umap_vnode->v_usecount,
		a->umap_lowervp, a->umap_lowervp->v_usecount,
		fil, lno);
#endif
	return a->umap_lowervp;
}
#endif

/* umap_mapids maps all of the ids in a credential, both user and group. */

umap_mapids(v_mount,credp)
	struct mount *v_mount;
	struct ucred *credp;
{
	int i,gid,uid,unentries,gnentries,*groupmap,*usermap;

	unentries =  MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
	usermap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
	gnentries =  MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
	groupmap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);

	/* Find uid entry in map */

	uid = umap_findid(credp->cr_uid,usermap,unentries);

	if (uid != -1) {
		credp->cr_uid =
			(u_short)uid;
	} else 
		credp->cr_uid = (u_short)NOBODY;

	/* Find gid entry in map */

	gid = umap_findid(credp->cr_gid,groupmap,gnentries);

	if (gid != -1) {
		credp->cr_gid =
			(u_short)gid;
	} else 
		credp->cr_gid = (u_short)NULLGROUP;

	/* Now we must map each of the set of groups in the cr_groups 
		structure. */

	i = 0;
	while (credp->cr_groups[i] != 0)
	{
		gid = umap_findid(credp->cr_groups[i],groupmap,
			gnentries);
		
		if (gid != -1) 
			credp->cr_groups[i++] = (u_short)gid;
		else
			credp->cr_groups[i++] = (u_short)NULLGROUP;

	}
}

/* umap_findid is called by various routines in umap_vnodeops.c to
 * find a user or group id in a map.
 */

umap_findid(id,map,nentries)
	ushort id;
	int map[][2];
	int nentries;
{
	int i;

	/* Find uid entry in map */
	i = 0;
	while ((i<nentries) && ((u_short)(map[i][0] ) != id))
		i++;

	if ( i < nentries )
		return (map[i][1]);
	else
		return (-1);

}

/* umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
 * find a user or group id in a map, in reverse.
 */

umap_reverse_findid(id,map,nentries)
	ushort id;
	int map[][2];
	int nentries;
{
	int i;

	/* Find uid entry in map */
	i = 0;
	while ((i<nentries) && ((u_short)(map[i][1] ) != id))
		i++;

	if ( i < nentries )
		return (map[i][0]);
	else
		return (-1);

}
Commit	Line	Data
461c058b JH	1	/*
	2	* Copyright (c) 1992 The Regents of the University of California
	3	* Copyright (c) 1990, 1992 Jan-Simon Pendry
	4	* All rights reserved.
	5	*
	6	* This code is derived from software donated to Berkeley by
	7	* Jan-Simon Pendry.
	8	*
	9	* %sccs.include.redist.c%
	10	*
	11	* @(#)lofs_subr.c 1.2 (Berkeley) 6/18/92
	12	*
	13	* $Id: lofs_subr.c,v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
	14	*/
	15
	16	#include <sys/param.h>
	17	#include <sys/systm.h>
	18	#include <sys/time.h>
	19	#include <sys/types.h>
	20	#include <sys/vnode.h>
	21	#include <sys/mount.h>
	22	#include <sys/namei.h>
	23	#include <sys/malloc.h>
	24	#include <umapfs/umap.h>
	25
	26	#define LOG2_SIZEVNODE 7 /* log2(sizeof struct vnode) */
	27	#define NUMAPNODECACHE 16
	28	#define UMAP_NHASH(vp) ((((u_long)vp)>>LOG2_SIZEVNODE) & (NUMAPNODECACHE-1))
	29
	30	/*
	31	* Null layer cache:
	32	* Each cache entry holds a reference to the target vnode
	33	* along with a pointer to the alias vnode. When an
	34	* entry is added the target vnode is VREF'd. When the
	35	* alias is removed the target vnode is vrele'd.
	36	*/
	37
	38	/*
	39	* Cache head
	40	*/
	41	struct umap_node_cache {
	42	struct umap_node *ac_forw;
	43	struct umap_node *ac_back;
	44	};
	45
	46	static struct umap_node_cache umap_node_cache[NUMAPNODECACHE];
	47
	48	/*
	49	* Initialise cache headers
	50	*/
	51	umapfs_init()
	52	{
	53	struct umap_node_cache *ac;
	54	#ifdef UMAPFS_DIAGNOSTIC
	55	printf("umapfs_init\n"); /* printed during system boot */
	56	#endif
	57
	58	for (ac = umap_node_cache; ac < umap_node_cache + NUMAPNODECACHE; ac++)
	59	ac->ac_forw = ac->ac_back = (struct umap_node *) ac;
	60	}
	61
	62	/*
	63	* Compute hash list for given target vnode
	64	*/
65	static struct umap_node_cache *
66	umap_node_hash(targetvp)
67	struct vnode *targetvp;
68	{
69	return (&umap_node_cache[UMAP_NHASH(targetvp)]);
70	}
71
461c058b JH	72	/*
	73	* Return alias for target vnode if already exists, else 0.
	74	*/
e0851395	75	static struct vnode *
461c058b JH	76	umap_node_find(mp, targetvp)
	77	struct mount *mp;
	78	struct vnode *targetvp;
	79	{
	80	struct umap_node_cache *hd;
	81	struct umap_node *a;
e0851395	82	struct vnode *vp;
461c058b JH	83
	84	#ifdef UMAPFS_DIAGNOSTIC
	85	printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
	86	#endif
	87
	88	/*
	89	* Find hash base, and then search the (two-way) linked
	90	* list looking for a umap_node structure which is referencing
	91	* the target vnode. If found, the increment the umap_node
	92	* reference count (but NOT the target vnode's VREF counter).
	93	*/
	94	hd = umap_node_hash(targetvp);
	95
e0851395	96	loop:
461c058b JH	97	for (a = hd->ac_forw; a != (struct umap_node *) hd; a = a->umap_forw) {
461c058b JH	98	if (a->umap_lowervp == targetvp && a->umap_vnode->v_mount == mp) {
e0851395 JH	99	vp = UMAPTOV(a);
	100	/*
	101	* We need vget for the VXLOCK
	102	* stuff, but we don't want to lock
	103	* the lower node.
	104	*/
	105	if (vget_nolock(vp)) {
	106	printf ("null_node_find: vget failed.\n");
	107	goto loop;
	108	};
	109	return (vp);
461c058b JH	110	}
	111	}
	112
	113	#ifdef UMAPFS_DIAGNOSTIC
	114	printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
	115	#endif
	116
	117	return (0);
	118	}
	119
e0851395 JH	120	/*
	121	* Make a new umap_node node.
	122	* Vp is the alias vnode, lofsvp is the target vnode.
	123	* Maintain a reference to (targetvp).
	124	*/
	125	static int
	126	umap_node_alloc(mp, lowervp, vpp)
	127	struct mount *mp;
	128	struct vnode *lowervp;
	129	struct vnode **vpp;
	130	{
	131	struct umap_node_cache *hd;
	132	struct umap_node *xp;
	133	struct vnode othervp, vp;
	134	int error;
	135
	136	if (error = getnewvnode(VT_UFS, mp, umap_vnodeop_p, vpp))
	137	return (error); /* XXX: VT_UMAP above */
	138	vp = *vpp;
	139
	140	MALLOC(xp, struct umap_node *, sizeof(struct umap_node), M_TEMP, M_WAITOK);
	141	vp->v_type = lowervp->v_type;
	142	xp->umap_vnode = vp;
	143	vp->v_data = xp;
	144	xp->umap_lowervp = lowervp;
	145	/*
	146	* Before we insert our new node onto the hash chains,
	147	* check to see if someone else has beaten us to it.
	148	* (We could have slept in MALLOC.)
	149	*/
	150	if (othervp = umap_node_find(lowervp)) {
	151	FREE(xp, M_TEMP);
	152	vp->v_type = VBAD; /* node is discarded */
	153	vp->v_usecount = 0; /* XXX */
	154	*vpp = othervp;
	155	return 0;
	156	};
	157	VREF(lowervp); /* Extra VREF will be vrele'd in umap_node_create */
	158	hd = umap_node_hash(lowervp);
	159	insque(xp, hd);
	160	return 0;
	161	}
	162
	163
461c058b JH	164	/*
	165	* Try to find an existing umap_node vnode refering
	166	* to it, otherwise make a new umap_node vnode which
	167	* contains a reference to the target vnode.
	168	*/
	169	int
	170	umap_node_create(mp, targetvp, newvpp)
	171	struct mount *mp;
	172	struct vnode *targetvp;
	173	struct vnode **newvpp;
	174	{
461c058b JH	175	struct vnode *aliasvp;
461c058b JH	176
e0851395	177	if (aliasvp = umap_node_find(mp, targetvp)) {
461c058b JH	178	/*
	179	* Take another reference to the alias vnode
	180	*/
	181	#ifdef UMAPFS_DIAGNOSTIC
	182	vprint("umap_node_create: exists", ap->umap_vnode);
	183	#endif
e0851395	184	/* VREF(aliasvp); */
461c058b JH	185	} else {
	186	int error;
	187
	188	/*
	189	* Get new vnode.
	190	*/
	191	#ifdef UMAPFS_DIAGNOSTIC
	192	printf("umap_node_create: create new alias vnode\n");
	193	#endif
461c058b JH	194	/*
	195	* Make new vnode reference the umap_node.
	196	*/
e0851395 JH	197	if (error = umap_node_alloc(mp, targetvp, &aliasvp))
e0851395 JH	198	return error;
461c058b JH	199
	200	/*
	201	* aliasvp is already VREF'd by getnewvnode()
	202	*/
	203	}
	204
	205	vrele(targetvp);
	206
	207	#ifdef UMAPFS_DIAGNOSTIC
	208	vprint("umap_node_create: alias", aliasvp);
	209	vprint("umap_node_create: target", targetvp);
	210	#endif
	211
	212	*newvpp = aliasvp;
	213	return (0);
	214	}
	215	#ifdef UMAPFS_DIAGNOSTIC
	216	int umap_checkvp_barrier = 1;
	217	struct vnode *
	218	umap_checkvp(vp, fil, lno)
	219	struct vnode *vp;
	220	char *fil;
	221	int lno;
	222	{
	223	struct umap_node *a = VTOUMAP(vp);
	224	#if 0
	225	/*
	226	* Can't do this check because vop_reclaim runs
	227	* with funny vop vector.
	228	*/
	229	if (vp->v_op != umap_vnodeop_p) {
	230	printf ("umap_checkvp: on non-umap-node\n");
	231	while (umap_checkvp_barrier) /WAIT/ ;
	232	panic("umap_checkvp");
	233	};
	234	#endif
	235	if (a->umap_lowervp == NULL) {
	236	/* Should never happen */
	237	int i; u_long *p;
	238	printf("vp = %x, ZERO ptr\n", vp);
	239	for (p = (u_long *) a, i = 0; i < 8; i++)
	240	printf(" %x", p[i]);
	241	printf("\n");
	242	/* wait for debugger */
	243	while (umap_checkvp_barrier) /WAIT/ ;
	244	panic("umap_checkvp");
	245	}
	246	if (a->umap_lowervp->v_usecount < 1) {
	247	int i; u_long *p;
	248	printf("vp = %x, unref'ed lowervp\n", vp);
	249	for (p = (u_long *) a, i = 0; i < 8; i++)
	250	printf(" %x", p[i]);
	251	printf("\n");
	252	/* wait for debugger */
	253	while (umap_checkvp_barrier) /WAIT/ ;
	254	panic ("umap with unref'ed lowervp");
	255	};
	256	#if 0
	257	printf("umap %x/%d -> %x/%d [%s, %d]\n",
	258	a->umap_vnode, a->umap_vnode->v_usecount,
	259	a->umap_lowervp, a->umap_lowervp->v_usecount,
	260	fil, lno);
	261	#endif
	262	return a->umap_lowervp;
263	}
264	#endif
265
266	/* umap_mapids maps all of the ids in a credential, both user and group. */
267
e0851395 JH	268	umap_mapids(v_mount,credp)
e0851395 JH	269	struct mount *v_mount;
461c058b	270	struct ucred *credp;
461c058b	271	{
e0851395 JH	272	int i,gid,uid,unentries,gnentries,groupmap,usermap;
	273
	274	unentries = MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
	275	usermap = &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
	276	gnentries = MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
	277	groupmap = &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);
461c058b JH	278
	279	/* Find uid entry in map */
	280
	281	uid = umap_findid(credp->cr_uid,usermap,unentries);
	282
	283	if (uid != -1) {
461c058b JH	284	credp->cr_uid =
	285	(u_short)uid;
	286	} else
e0851395	287	credp->cr_uid = (u_short)NOBODY;
461c058b JH	288
	289	/* Find gid entry in map */
	290
	291	gid = umap_findid(credp->cr_gid,groupmap,gnentries);
	292
	293	if (gid != -1) {
461c058b JH	294	credp->cr_gid =
	295	(u_short)gid;
	296	} else
e0851395	297	credp->cr_gid = (u_short)NULLGROUP;
461c058b JH	298
	299	/* Now we must map each of the set of groups in the cr_groups
	300	structure. */
	301
	302	i = 0;
	303	while (credp->cr_groups[i] != 0)
	304	{
	305	gid = umap_findid(credp->cr_groups[i],groupmap,
	306	gnentries);
	307
	308	if (gid != -1)
	309	credp->cr_groups[i++] = (u_short)gid;
	310	else
	311	credp->cr_groups[i++] = (u_short)NULLGROUP;
	312
	313	}
	314	}
	315
	316	/* umap_findid is called by various routines in umap_vnodeops.c to
	317	* find a user or group id in a map.
	318	*/
	319
	320	umap_findid(id,map,nentries)
	321	ushort id;
	322	int map[][2];
	323	int nentries;
	324	{
	325	int i;
	326
	327	/* Find uid entry in map */
	328	i = 0;
	329	while ((i<nentries) && ((u_short)(map[i][0] ) != id))
	330	i++;
	331
	332	if ( i < nentries )
	333	return (map[i][1]);
	334	else
	335	return (-1);
	336
	337	}
	338
	339	/* umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
	340	* find a user or group id in a map, in reverse.
	341	*/
	342
	343	umap_reverse_findid(id,map,nentries)
	344	ushort id;
	345	int map[][2];
	346	int nentries;
	347	{
	348	int i;
	349
	350	/* Find uid entry in map */
	351	i = 0;
	352	while ((i<nentries) && ((u_short)(map[i][1] ) != id))
	353	i++;
	354
	355	if ( i < nentries )
	356	return (map[i][0]);
	357	else
	358	return (-1);
	359
	360	}
	361