freebsd-skq/sys/miscfs/umapfs/umap_vnops.c
1994-05-24 10:09:53 +00:00

489 lines
13 KiB
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
* the UCLA Ficus project.
*
* 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.
*
* @(#)umap_vnops.c 8.3 (Berkeley) 1/5/94
*/
/*
* Umap Layer
*/
#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 <sys/buf.h>
#include <miscfs/umapfs/umap.h>
int umap_bug_bypass = 0; /* for debugging: enables bypass printf'ing */
/*
* This is the 10-Apr-92 bypass routine.
* See null_vnops.c:null_bypass for more details.
*/
int
umap_bypass(ap)
struct vop_generic_args /* {
struct vnodeop_desc *a_desc;
<other random data follows, presumably>
} */ *ap;
{
extern int (**umap_vnodeop_p)(); /* not extern, really "forward" */
struct ucred **credpp = 0, *credp = 0;
struct ucred *savecredp, *savecompcredp = 0;
struct ucred *compcredp = 0;
struct vnode **this_vp_p;
int error;
struct vnode *old_vps[VDESC_MAX_VPS];
struct vnode *vp1 = 0;
struct vnode **vps_p[VDESC_MAX_VPS];
struct vnode ***vppp;
struct vnodeop_desc *descp = ap->a_desc;
int reles, i;
struct componentname **compnamepp = 0;
if (umap_bug_bypass)
printf ("umap_bypass: %s\n", descp->vdesc_name);
#ifdef SAFETY
/*
* We require at least one vp.
*/
if (descp->vdesc_vp_offsets == NULL ||
descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
panic ("umap_bypass: no vp's in map.\n");
#endif
/*
* Map the vnodes going in.
* Later, we'll invoke the operation based on
* the first mapped vnode's operation vector.
*/
reles = descp->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
break; /* bail out at end of list */
vps_p[i] = this_vp_p =
VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap);
if (i == 0) {
vp1 = *vps_p[0];
}
/*
* We're not guaranteed that any but the first vnode
* are of our type. Check for and don't map any
* that aren't. (Must map first vp or vclean fails.)
*/
if (i && (*this_vp_p)->v_op != umap_vnodeop_p) {
old_vps[i] = NULL;
} else {
old_vps[i] = *this_vp_p;
*(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
if (reles & 1)
VREF(*this_vp_p);
}
}
/*
* Fix the credentials. (That's the purpose of this layer.)
*/
if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
credpp = VOPARG_OFFSETTO(struct ucred**,
descp->vdesc_cred_offset, ap);
/* Save old values */
savecredp = (*credpp);
(*credpp) = crdup(savecredp);
credp = *credpp;
if (umap_bug_bypass && credp->cr_uid != 0)
printf("umap_bypass: user was %d, group %d\n",
credp->cr_uid, credp->cr_gid);
/* Map all ids in the credential structure. */
umap_mapids(vp1->v_mount, credp);
if (umap_bug_bypass && credp->cr_uid != 0)
printf("umap_bypass: user now %d, group %d\n",
credp->cr_uid, credp->cr_gid);
}
/* BSD often keeps a credential in the componentname structure
* for speed. If there is one, it better get mapped, too.
*/
if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
compnamepp = VOPARG_OFFSETTO(struct componentname**,
descp->vdesc_componentname_offset, ap);
compcredp = (*compnamepp)->cn_cred;
savecompcredp = compcredp;
compcredp = (*compnamepp)->cn_cred = crdup(savecompcredp);
if (umap_bug_bypass && compcredp->cr_uid != 0)
printf("umap_bypass: component credit user was %d, group %d\n",
compcredp->cr_uid, compcredp->cr_gid);
/* Map all ids in the credential structure. */
umap_mapids(vp1->v_mount, compcredp);
if (umap_bug_bypass && compcredp->cr_uid != 0)
printf("umap_bypass: component credit user now %d, group %d\n",
compcredp->cr_uid, compcredp->cr_gid);
}
/*
* Call the operation on the lower layer
* with the modified argument structure.
*/
error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
/*
* Maintain the illusion of call-by-value
* by restoring vnodes in the argument structure
* to their original value.
*/
reles = descp->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
break; /* bail out at end of list */
if (old_vps[i]) {
*(vps_p[i]) = old_vps[i];
if (reles & 1)
vrele(*(vps_p[i]));
};
};
/*
* Map the possible out-going vpp
* (Assumes that the lower layer always returns
* a VREF'ed vpp unless it gets an error.)
*/
if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
!(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
!error) {
if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
goto out;
vppp = VOPARG_OFFSETTO(struct vnode***,
descp->vdesc_vpp_offset, ap);
error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp);
};
out:
/*
* Free duplicate cred structure and restore old one.
*/
if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
if (umap_bug_bypass && credp && credp->cr_uid != 0)
printf("umap_bypass: returning-user was %d\n",
credp->cr_uid);
crfree(credp);
(*credpp) = savecredp;
if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
printf("umap_bypass: returning-user now %d\n\n",
(*credpp)->cr_uid);
}
if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0)
printf("umap_bypass: returning-component-user was %d\n",
compcredp->cr_uid);
crfree(compcredp);
(*compnamepp)->cn_cred = savecompcredp;
if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
printf("umap_bypass: returning-component-user now %d\n",
compcredp->cr_uid);
}
return (error);
}
/*
* We handle getattr to change the fsid.
*/
int
umap_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
short uid, gid;
int error, tmpid, nentries, gnentries;
u_long (*mapdata)[2], (*gmapdata)[2];
struct vnode **vp1p;
struct vnodeop_desc *descp = ap->a_desc;
if (error = umap_bypass(ap))
return (error);
/* Requires that arguments be restored. */
ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
/*
* Umap needs to map the uid and gid returned by a stat
* into the proper values for this site. This involves
* finding the returned uid in the mapping information,
* translating it into the uid on the other end,
* and filling in the proper field in the vattr
* structure pointed to by ap->a_vap. The group
* is easier, since currently all groups will be
* translate to the NULLGROUP.
*/
/* Find entry in map */
uid = ap->a_vap->va_uid;
gid = ap->a_vap->va_gid;
if (umap_bug_bypass)
printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid,
gid);
vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
nentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
mapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
gnentries = MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
gmapdata = (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
/* Reverse map the uid for the vnode. Since it's a reverse
map, we can't use umap_mapids() to do it. */
tmpid = umap_reverse_findid(uid, mapdata, nentries);
if (tmpid != -1) {
ap->a_vap->va_uid = (uid_t) tmpid;
if (umap_bug_bypass)
printf("umap_getattr: original uid = %d\n", uid);
} else
ap->a_vap->va_uid = (uid_t) NOBODY;
/* Reverse map the gid for the vnode. */
tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
if (tmpid != -1) {
ap->a_vap->va_gid = (gid_t) tmpid;
if (umap_bug_bypass)
printf("umap_getattr: original gid = %d\n", gid);
} else
ap->a_vap->va_gid = (gid_t) NULLGROUP;
return (0);
}
int
umap_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
} */ *ap;
{
/*
* Do nothing (and _don't_ bypass).
* Wait to vrele lowervp until reclaim,
* so that until then our umap_node is in the
* cache and reusable.
*
*/
return (0);
}
int
umap_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct umap_node *xp = VTOUMAP(vp);
struct vnode *lowervp = xp->umap_lowervp;
/* After this assignment, this node will not be re-used. */
xp->umap_lowervp = NULL;
remque(xp);
FREE(vp->v_data, M_TEMP);
vp->v_data = NULL;
vrele(lowervp);
return (0);
}
int
umap_strategy(ap)
struct vop_strategy_args /* {
struct buf *a_bp;
} */ *ap;
{
struct buf *bp = ap->a_bp;
int error;
struct vnode *savedvp;
savedvp = bp->b_vp;
bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
error = VOP_STRATEGY(ap->a_bp);
bp->b_vp = savedvp;
return (error);
}
int
umap_bwrite(ap)
struct vop_bwrite_args /* {
struct buf *a_bp;
} */ *ap;
{
struct buf *bp = ap->a_bp;
int error;
struct vnode *savedvp;
savedvp = bp->b_vp;
bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
error = VOP_BWRITE(ap->a_bp);
bp->b_vp = savedvp;
return (error);
}
int
umap_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
printf("\ttag VT_UMAPFS, vp=%x, lowervp=%x\n", vp, UMAPVPTOLOWERVP(vp));
return (0);
}
int
umap_rename(ap)
struct vop_rename_args /* {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */ *ap;
{
int error;
struct componentname *compnamep;
struct ucred *compcredp, *savecompcredp;
struct vnode *vp;
/*
* Rename is irregular, having two componentname structures.
* We need to map the cre in the second structure,
* and then bypass takes care of the rest.
*/
vp = ap->a_fdvp;
compnamep = ap->a_tcnp;
compcredp = compnamep->cn_cred;
savecompcredp = compcredp;
compcredp = compnamep->cn_cred = crdup(savecompcredp);
if (umap_bug_bypass && compcredp->cr_uid != 0)
printf("umap_rename: rename component credit user was %d, group %d\n",
compcredp->cr_uid, compcredp->cr_gid);
/* Map all ids in the credential structure. */
umap_mapids(vp->v_mount, compcredp);
if (umap_bug_bypass && compcredp->cr_uid != 0)
printf("umap_rename: rename component credit user now %d, group %d\n",
compcredp->cr_uid, compcredp->cr_gid);
error = umap_bypass(ap);
/* Restore the additional mapped componentname cred structure. */
crfree(compcredp);
compnamep->cn_cred = savecompcredp;
return error;
}
/*
* Global vfs data structures
*/
/*
* XXX - strategy, bwrite are hand coded currently. They should
* go away with a merged buffer/block cache.
*
*/
int (**umap_vnodeop_p)();
struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
{ &vop_default_desc, umap_bypass },
{ &vop_getattr_desc, umap_getattr },
{ &vop_inactive_desc, umap_inactive },
{ &vop_reclaim_desc, umap_reclaim },
{ &vop_print_desc, umap_print },
{ &vop_rename_desc, umap_rename },
{ &vop_strategy_desc, umap_strategy },
{ &vop_bwrite_desc, umap_bwrite },
{ (struct vnodeop_desc*) NULL, (int(*)()) NULL }
};
struct vnodeopv_desc umap_vnodeop_opv_desc =
{ &umap_vnodeop_p, umap_vnodeop_entries };