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minix/sys/fs/udf/udf_rename.c

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/* $NetBSD: udf_rename.c,v 1.10 2013/07/16 10:49:36 reinoud Exp $ */
/*
* Copyright (c) 2013 Reinoud Zandijk
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* Comments and trivial code from the reference implementation in tmpfs.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: udf_rename.c,v 1.10 2013/07/16 10:49:36 reinoud Exp $");
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/kauth.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/vnode.h>
#include <sys/vnode_if.h>
#include <miscfs/genfs/genfs.h>
#include <fs/udf/ecma167-udf.h>
#include <fs/udf/udf_mount.h>
#include <sys/dirhash.h>
#include "udf.h"
#include "udf_subr.h"
#include "udf_bswap.h"
/* forwards */
static int udf_sane_rename( struct vnode *, struct componentname *,
struct vnode *, struct componentname *,
kauth_cred_t, bool);
static bool udf_rmdired_p(struct vnode *);
static int udf_gro_lock_directory(struct mount *, struct vnode *);
static const struct genfs_rename_ops udf_genfs_rename_ops;
#define VTOI(vnode) ((struct udf_node *) (vnode)->v_data)
/*
* udf_sane_rename: The hairiest vop, with the saner API.
*
* Arguments:
*
* . fdvp (from directory vnode),
* . fcnp (from component name),
* . tdvp (to directory vnode),
* . tcnp (to component name),
* . cred (credentials structure), and
* . posixly_correct (flag for behaviour if target & source link same file).
*
* fdvp and tdvp may be the same, and must be referenced and unlocked.
*/
static int
udf_sane_rename( struct vnode *fdvp, struct componentname *fcnp,
struct vnode *tdvp, struct componentname *tcnp,
kauth_cred_t cred, bool posixly_correct)
{
DPRINTF(CALL, ("udf_sane_rename '%s' -> '%s'\n",
fcnp->cn_nameptr, tcnp->cn_nameptr));
return genfs_sane_rename(&udf_genfs_rename_ops,
fdvp, fcnp, NULL, tdvp, tcnp, NULL,
cred, posixly_correct);
}
/*
* udf_rename: the hairiest vop, with the insanest API. Pass to
* genfs_insane_rename immediately.
*/
int
udf_rename(void *v)
{
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 = v;
DPRINTF(CALL, ("udf_rename called\n"));
return genfs_insane_rename(ap, &udf_sane_rename);
}
/*
* udf_gro_directory_empty_p: return true if the directory vp is empty. dvp is
* its parent.
*
* vp and dvp must be locked and referenced.
*/
static bool
udf_gro_directory_empty_p(struct mount *mp, kauth_cred_t cred,
struct vnode *vp, struct vnode *dvp)
{
struct udf_node *udf_node = VTOI(vp);
int error, isempty;
KASSERT(mp != NULL);
KASSERT(vp != NULL);
KASSERT(dvp != NULL);
KASSERT(vp != dvp);
KASSERT(vp->v_mount == mp);
KASSERT(dvp->v_mount == mp);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
DPRINTF(CALL, ("udf_gro_directory_empty_p called\n"));
/* make sure our `leaf' node's hash is populated */
dirhash_get(&udf_node->dir_hash);
error = udf_dirhash_fill(udf_node);
if (error) {
dirhash_put(udf_node->dir_hash);
/* VERY unlikely, answer its not empty */
return 0;
}
/* check to see if the directory is empty */
isempty = dirhash_dir_isempty(udf_node->dir_hash);
dirhash_put(udf_node->dir_hash);
return isempty;
}
/*
* udf_gro_rename_check_possible: check whether a rename is possible
* independent of credentials.
*/
static int
udf_gro_rename_check_possible(struct mount *mp,
struct vnode *fdvp, struct vnode *fvp,
struct vnode *tdvp, struct vnode *tvp)
{
(void)mp;
KASSERT(mp != NULL);
KASSERT(fdvp != NULL);
KASSERT(fvp != NULL);
KASSERT(tdvp != NULL);
KASSERT(fdvp != fvp);
KASSERT(fdvp != tvp);
KASSERT(tdvp != fvp);
KASSERT(tdvp != tvp);
KASSERT(fvp != tvp);
KASSERT(fdvp->v_type == VDIR);
KASSERT(tdvp->v_type == VDIR);
KASSERT(fdvp->v_mount == mp);
KASSERT(fvp->v_mount == mp);
KASSERT(tdvp->v_mount == mp);
KASSERT((tvp == NULL) || (tvp->v_mount == mp));
KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
DPRINTF(CALL, ("udf_gro_rename_check_possible called\n"));
/* flags not implemented since they are not defined (yet) in UDF */
return 0;
}
/*
* udf_gro_rename_check_permitted: check whether a rename is permitted given
* our credentials.
*/
static int
udf_gro_rename_check_permitted(struct mount *mp, kauth_cred_t cred,
struct vnode *fdvp, struct vnode *fvp,
struct vnode *tdvp, struct vnode *tvp)
{
struct udf_node *fdir_node = VTOI(fdvp);
struct udf_node *tdir_node = VTOI(tdvp);
struct udf_node *f_node = VTOI(fvp);
struct udf_node *t_node = (tvp? VTOI(tvp): NULL);
mode_t fdmode, tdmode;
uid_t fduid, tduid, fuid, tuid;
gid_t gdummy;
(void)mp;
KASSERT(mp != NULL);
KASSERT(fdvp != NULL);
KASSERT(fvp != NULL);
KASSERT(tdvp != NULL);
KASSERT(fdvp != fvp);
KASSERT(fdvp != tvp);
KASSERT(tdvp != fvp);
KASSERT(tdvp != tvp);
KASSERT(fvp != tvp);
KASSERT(fdvp->v_type == VDIR);
KASSERT(tdvp->v_type == VDIR);
KASSERT(fdvp->v_mount == mp);
KASSERT(fvp->v_mount == mp);
KASSERT(tdvp->v_mount == mp);
KASSERT((tvp == NULL) || (tvp->v_mount == mp));
KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
DPRINTF(CALL, ("udf_gro_rename_check_permitted called\n"));
fdmode = udf_getaccessmode(fdir_node);
tdmode = udf_getaccessmode(tdir_node);
udf_getownership(fdir_node, &fduid, &gdummy);
udf_getownership(tdir_node, &tduid, &gdummy);
udf_getownership(f_node, &fuid, &gdummy);
tuid = 0;
if (t_node)
udf_getownership(t_node, &tuid, &gdummy);
return genfs_ufslike_rename_check_permitted(cred,
fdvp, fdmode, fduid,
fvp, fuid,
tdvp, tdmode, tduid,
tvp, tuid);
}
/*
* udf_gro_remove_check_possible: check whether a remove is possible
* independent of credentials.
*
* XXX could check for special attributes?
*/
static int
udf_gro_remove_check_possible(struct mount *mp,
struct vnode *dvp, struct vnode *vp)
{
(void)mp;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(vp != NULL);
KASSERT(dvp != vp);
KASSERT(dvp->v_type == VDIR);
KASSERT(vp->v_type != VDIR);
KASSERT(dvp->v_mount == mp);
KASSERT(vp->v_mount == mp);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
DPRINTF(CALL, ("udf_gro_remove_check_possible called\n"));
/* flags not implemented since they are not defined (yet) in UDF */
return 0;
}
/*
* udf_gro_remove_check_permitted: check whether a remove is permitted given
* our credentials.
*/
static int
udf_gro_remove_check_permitted(struct mount *mp, kauth_cred_t cred,
struct vnode *dvp, struct vnode *vp)
{
struct udf_node *dir_node = VTOI(dvp);
struct udf_node *udf_node = VTOI(vp);
mode_t dmode;
uid_t duid, uid;
gid_t gdummy;
(void)mp;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(vp != NULL);
KASSERT(dvp != vp);
KASSERT(dvp->v_type == VDIR);
KASSERT(vp->v_type != VDIR);
KASSERT(dvp->v_mount == mp);
KASSERT(vp->v_mount == mp);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
DPRINTF(CALL, ("udf_gro_remove_check_permitted called\n"));
dmode = udf_getaccessmode(dir_node);
udf_getownership(dir_node, &duid, &gdummy);
udf_getownership(udf_node, &uid, &gdummy);
return genfs_ufslike_remove_check_permitted(cred,
dvp, dmode, duid,
vp, uid);
}
/*
* udf_gro_rename: actually perform the rename operation.
*/
static int
udf_gro_rename(struct mount *mp, kauth_cred_t cred,
struct vnode *fdvp, struct componentname *fcnp,
void *fde, struct vnode *fvp,
struct vnode *tdvp, struct componentname *tcnp,
void *tde, struct vnode *tvp)
{
struct udf_node *fnode, *fdnode, *tnode, *tdnode;
struct vattr fvap;
int error;
(void)cred;
KASSERT(mp != NULL);
KASSERT(fdvp != NULL);
KASSERT(fcnp != NULL);
KASSERT(fvp != NULL);
KASSERT(tdvp != NULL);
KASSERT(tcnp != NULL);
KASSERT(fdvp != fvp);
KASSERT(fdvp != tvp);
KASSERT(tdvp != fvp);
KASSERT(tdvp != tvp);
KASSERT(fvp != tvp);
KASSERT(fdvp->v_mount == mp);
KASSERT(fvp->v_mount == mp);
KASSERT(tdvp->v_mount == mp);
KASSERT((tvp == NULL) || (tvp->v_mount == mp));
KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));
DPRINTF(CALL, ("udf_gro_rename called\n"));
DPRINTF(NODE, ("udf_gro_rename called : %s -> %s\n",
fcnp->cn_nameptr, tcnp->cn_nameptr));
fnode = VTOI(fvp);
fdnode = VTOI(fdvp);
tnode = (tvp == NULL) ? NULL : VTOI(tvp);
tdnode = VTOI(tdvp);
/* get attribute information */
error = VOP_GETATTR(fvp, &fvap, NULL);
if (error)
return error;
/* remove existing entry if present */
if (tvp)
udf_dir_detach(tdnode->ump, tdnode, tnode, tcnp);
/* create new directory entry for the node */
error = udf_dir_attach(tdnode->ump, tdnode, fnode, &fvap, tcnp);
if (error)
return error;
/* unlink old directory entry for the node, if failing, unattach new */
error = udf_dir_detach(tdnode->ump, fdnode, fnode, fcnp);
if (error)
goto rollback_attach;
if ((fdnode != tdnode) && (fvp->v_type == VDIR)) {
/* update fnode's '..' entry */
error = udf_dir_update_rootentry(fnode->ump, fnode, tdnode);
if (error)
goto rollback;
}
VN_KNOTE(fvp, NOTE_RENAME);
genfs_rename_cache_purge(fdvp, fvp, tdvp, tvp);
return 0;
rollback:
/* 'try' to recover from this situation */
udf_dir_attach(tdnode->ump, fdnode, fnode, &fvap, fcnp);
rollback_attach:
udf_dir_detach(tdnode->ump, tdnode, fnode, tcnp);
return error;
}
/*
* udf_gro_remove: rename an object over another link to itself, effectively
* removing just the original link.
*/
static int
udf_gro_remove(struct mount *mp, kauth_cred_t cred,
struct vnode *dvp, struct componentname *cnp, void *de, struct vnode *vp)
{
struct udf_node *dir_node, *udf_node;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(cnp != NULL);
KASSERT(vp != NULL);
KASSERT(dvp != vp);
KASSERT(dvp->v_mount == mp);
KASSERT(vp->v_mount == mp);
KASSERT(dvp->v_type == VDIR);
KASSERT(vp->v_type != VDIR);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
DPRINTF(CALL, ("udf_gro_remove called\n"));
dir_node = VTOI(dvp);
udf_node = VTOI(vp);
udf_dir_detach(dir_node->ump, dir_node, udf_node, cnp);
return 0;
}
/*
* udf_gro_lookup: look up and save the lookup results.
*/
static int
udf_gro_lookup(struct mount *mp, struct vnode *dvp,
struct componentname *cnp, void *de_ret, struct vnode **vp_ret)
{
struct udf_node *dir_node, *res_node;
struct long_ad icb_loc;
const char *name;
int namelen, error;
int found;
(void)mp;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(cnp != NULL);
KASSERT(vp_ret != NULL);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
dir_node = VTOI(dvp);
DPRINTF(CALL, ("udf_gro_lookup called\n"));
/* lookup filename in the directory; location icb_loc */
name = cnp->cn_nameptr;
namelen = cnp->cn_namelen;
error = udf_lookup_name_in_dir(dvp, name, namelen,
&icb_loc, &found);
if (error)
return error;
if (!found)
return ENOENT;
DPRINTF(LOOKUP, ("udf_gro_lookup found '%s'\n", name));
error = udf_get_node(dir_node->ump, &icb_loc, &res_node);
if (error)
return error;
*vp_ret = res_node->vnode;
VOP_UNLOCK(res_node->vnode);
return 0;
}
/*
* udf_rmdired_p: check whether the directory vp has been rmdired.
*
* vp must be locked and referenced.
*/
static bool
udf_rmdired_p(struct vnode *vp)
{
DPRINTF(CALL, ("udf_rmdired_p called\n"));
KASSERT(vp != NULL);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
KASSERT(vp->v_type == VDIR);
return (VTOI(vp)->i_flags & IN_DELETED);
}
/*
* udf_gro_genealogy: analyze the genealogy of the source and target
* directories.
*/
static int
udf_gro_genealogy(struct mount *mp, kauth_cred_t cred,
struct vnode *fdvp, struct vnode *tdvp,
struct vnode **intermediate_node_ret)
{
struct udf_mount *ump;
struct udf_node *parent_node;
struct vnode *vp, *dvp;
struct long_ad parent_loc;
const char *name;
int namelen;
int error, found;
(void)cred;
KASSERT(mp != NULL);
KASSERT(fdvp != NULL);
KASSERT(tdvp != NULL);
KASSERT(fdvp != tdvp);
KASSERT(intermediate_node_ret != NULL);
KASSERT(fdvp->v_mount == mp);
KASSERT(tdvp->v_mount == mp);
KASSERT(fdvp->v_type == VDIR);
KASSERT(tdvp->v_type == VDIR);
DPRINTF(CALL, ("udf_gro_genealogy called\n"));
/*
* We need to provisionally lock tdvp to keep rmdir from deleting it
* -- or any ancestor -- at an inopportune moment.
*
* XXX WHY is this not in genfs's rename? XXX
*/
error = udf_gro_lock_directory(mp, tdvp);
if (error)
return error;
name = "..";
namelen = 2;
error = 0;
ump = VTOI(tdvp)->ump;
/* if nodes are equal, it is no use looking */
KASSERT(udf_compare_icb(&VTOI(fdvp)->loc, &VTOI(tdvp)->loc) != 0);
/* start at destination vnode and walk up the tree */
vp = tdvp;
vref(vp);
for (;;) {
KASSERT(vp != NULL);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
KASSERT(vp->v_mount == mp);
KASSERT(vp->v_type == VDIR);
KASSERT(!udf_rmdired_p(vp));
DPRINTF(NODE, ("udf_gro_genealogy : "
"fdvp %p, looking at vp %p\n",
fdvp, vp));
/* sanity check */
if (vp->v_type != VDIR) {
vput(vp);
return ENOTDIR;
}
/* go down one level */
error = udf_lookup_name_in_dir(vp, name, namelen,
&parent_loc, &found);
DPRINTF(NODE, ("\tlookup of parent '..' resulted in error %d, "
"found %d\n", error, found));
if (!found)
error = ENOENT;
if (error) {
vput(vp);
return error;
}
/* did we encounter the root node? i.e. loop back */
if (udf_compare_icb(&parent_loc, &VTOI(vp)->loc) == 0) {
DPRINTF(NODE, ("ROOT found!\n"));
vput(vp);
*intermediate_node_ret = NULL;
return 0;
}
/* Did we find that fdvp is an ancestor of tdvp? */
if (udf_compare_icb(&parent_loc, &VTOI(fdvp)->loc) == 0) {
DPRINTF(NODE, ("fdvp is ancestor of tdvp\n"));
*intermediate_node_ret = vp;
VOP_UNLOCK(vp);
return 0;
}
/*
* Unlock vp so that we can lock the parent, but keep child vp
* referenced until after we have found the parent, so that
* parent_node will not be recycled.
*/
DPRINTF(NODE, ("\tgetting the parent node\n"));
VOP_UNLOCK(vp);
error = udf_get_node(ump, &parent_loc, &parent_node);
vrele(vp);
if (error)
return error;
dvp = parent_node->vnode;
/* switch */
KASSERT(dvp != NULL);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
vp = dvp;
/* sanity check */
if (vp->v_type != VDIR) {
/*
* Odd, but can happen if we loose the race and the
* '..' node has been recycled.
*/
vput(vp);
return ENOTDIR;
}
if (udf_rmdired_p(vp)) {
vput(vp);
return ENOENT;
}
}
}
/*
* udf_gro_lock_directory: lock the directory vp, but fail if it has been
* rmdir'd.
*/
static int
udf_gro_lock_directory(struct mount *mp, struct vnode *vp)
{
(void)mp;
KASSERT(mp != NULL);
KASSERT(vp != NULL);
KASSERT(vp->v_mount == mp);
DPRINTF(CALL, ("udf_gro_lock_directory called\n"));
DPRINTF(LOCKING, ("udf_gro_lock_directory called\n"));
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (udf_rmdired_p(vp)) {
VOP_UNLOCK(vp);
return ENOENT;
}
return 0;
}
static const struct genfs_rename_ops udf_genfs_rename_ops = {
.gro_directory_empty_p = udf_gro_directory_empty_p,
.gro_rename_check_possible = udf_gro_rename_check_possible,
.gro_rename_check_permitted = udf_gro_rename_check_permitted,
.gro_remove_check_possible = udf_gro_remove_check_possible,
.gro_remove_check_permitted = udf_gro_remove_check_permitted,
.gro_rename = udf_gro_rename,
.gro_remove = udf_gro_remove,
.gro_lookup = udf_gro_lookup,
.gro_genealogy = udf_gro_genealogy,
.gro_lock_directory = udf_gro_lock_directory,
};
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