BSD 4.4 Lite Kernel Sources

1 files changed, 488 insertions, 0 deletions

diff --git a/sys/fs/umapfs/umap_vnops.c b/sys/fs/umapfs/umap_vnops.c
new file mode 100644
index 0000000..287804e
--- /dev/null
+++ b/sys/fs/umapfs/umap_vnops.c
@@ -0,0 +1,488 @@
+/*
+ * 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 };