FreeBSD-5.3/sys/fs/umapfs/umap_vnops.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.
* 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 8.6 (Berkeley) 5/22/95
* $FreeBSD: src/sys/fs/umapfs/umap_vnops.c,v 1.40 2004/04/07 20:46:02 imp Exp $
*/
/*
* Umap Layer
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <fs/umapfs/umap.h>
#include <fs/nullfs/null.h>
static int umap_bug_bypass = 0; /* for debugging: enables bypass printf'ing */
SYSCTL_INT(_debug, OID_AUTO, umapfs_bug_bypass, CTLFLAG_RW,
&umap_bug_bypass, 0, "");
static int umap_bypass(struct vop_generic_args *ap);
static int umap_getattr(struct vop_getattr_args *ap);
static int umap_inactive(struct vop_inactive_args *ap);
static int umap_lock(struct vop_lock_args *ap);
static int umap_print(struct vop_print_args *ap);
static int umap_reclaim(struct vop_reclaim_args *ap);
static int umap_rename(struct vop_rename_args *ap);
static int umap_unlock(struct vop_unlock_args *ap);
/*
* This is the 10-Apr-92 bypass routine.
* See null_vnops.c:null_bypass for more details.
*/
static int
umap_bypass(ap)
struct vop_generic_args /* {
struct vnodeop_desc *a_desc;
<other random data follows, presumably>
} */ *ap;
{
struct ucred **credpp = 0, *credp = 0;
struct ucred *savecredp = 0, *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 DIAGNOSTIC
/*
* 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");
#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);
if (savecredp != NOCRED)
(*credpp) = crdup(savecredp);
credp = *credpp;
if (umap_bug_bypass && credp->cr_uid != 0)
printf("umap_bypass: user was %lu, group %lu\n",
(u_long)credp->cr_uid, (u_long)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 %lu, group %lu\n",
(u_long)credp->cr_uid, (u_long)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;
if (savecompcredp != NOCRED)
(*compnamepp)->cn_cred = crdup(savecompcredp);
compcredp = (*compnamepp)->cn_cred;
if (umap_bug_bypass && compcredp->cr_uid != 0)
printf(
"umap_bypass: component credit user was %lu, group %lu\n",
(u_long)compcredp->cr_uid,
(u_long)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 %lu, group %lu\n",
(u_long)compcredp->cr_uid,
(u_long)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);
if (*vppp)
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 %lu\n",
(u_long)credp->cr_uid);
if (savecredp != NOCRED) {
crfree(credp);
(*credpp) = savecredp;
if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
printf(
"umap_bypass: returning-user now %lu\n\n",
(u_long)(*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 %lu\n",
(u_long)compcredp->cr_uid);
if (savecompcredp != NOCRED) {
crfree(compcredp);
(*compnamepp)->cn_cred = savecompcredp;
if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
printf(
"umap_bypass: returning-component-user now %lu\n",
(u_long)compcredp->cr_uid);
}
}
return (error);
}
/*
* We handle getattr to change the fsid.
*/
static int
umap_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct thread *a_td;
} */ *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;
error = umap_bypass((struct vop_generic_args *)ap);
if (error)
return (error);
/*
* 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);
}
/*
* We need to process our own vnode lock and then clear the
* interlock flag as it applies only to our vnode, not the
* vnodes below us on the stack.
*/
static int
umap_lock(ap)
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct thread *a_td;
} */ *ap;
{
/*
* vop_nolock no longer exists. I could have pasted the code
* in so that it compiles, but that would be doing our users a
* great disservice. umapfs is about 5 years behind the nullfs
* code that it is derived from. The stub locking here guarantees
* a deadlock the moment a VOP_INACTIVE arrives. There is no point
* pasting the code that makes it compile either, because that just
* makes it Even More Wrong.
*/
vop_nolock(ap);
if ((ap->a_flags & LK_TYPE_MASK) == LK_DRAIN)
return (0);
ap->a_flags &= ~LK_INTERLOCK;
return (null_bypass((struct vop_generic_args *)ap));
}
/*
* We need to process our own vnode unlock and then clear the
* interlock flag as it applies only to our vnode, not the
* vnodes below us on the stack.
*/
static int
umap_unlock(ap)
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
struct thread *a_td;
} */ *ap;
{
vop_nounlock(ap);
ap->a_flags &= ~LK_INTERLOCK;
return (null_bypass((struct vop_generic_args *)ap));
}
static int
umap_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct umap_node *xp = VTOUMAP(vp);
struct vnode *lowervp = xp->umap_lowervp;
/*
* 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.
*
*/
VOP_INACTIVE(lowervp, ap->a_td);
VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
return (0);
}
static 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;
LIST_REMOVE(xp, umap_hash);
FREE(vp->v_data, M_TEMP);
vp->v_data = NULL;
vrele(lowervp);
return (0);
}
static int
umap_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
printf("\tvp=%p, lowervp=%p\n", vp, UMAPVPTOLOWERVP(vp));
return (0);
}
static 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 %lu, group %lu\n",
(u_long)compcredp->cr_uid, (u_long)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 %lu, group %lu\n",
(u_long)compcredp->cr_uid, (u_long)compcredp->cr_gid);
error = umap_bypass((struct vop_generic_args *)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.
*
*/
vop_t **umap_vnodeop_p;
static struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) umap_bypass },
{ &vop_getattr_desc, (vop_t *) umap_getattr },
{ &vop_inactive_desc, (vop_t *) umap_inactive },
{ &vop_lock_desc, (vop_t *) umap_lock },
{ &vop_print_desc, (vop_t *) umap_print },
{ &vop_reclaim_desc, (vop_t *) umap_reclaim },
{ &vop_rename_desc, (vop_t *) umap_rename },
{ &vop_unlock_desc, (vop_t *) umap_unlock },
{ NULL, NULL }
};
static struct vnodeopv_desc umap_vnodeop_opv_desc =
{ &umap_vnodeop_p, umap_vnodeop_entries };
VNODEOP_SET(umap_vnodeop_opv_desc);