Adapt tmpfs_rename to use genfs_rename.

This commit is contained in:
riastradh 2012-05-09 00:16:07 +00:00
parent 5ecfdf8dea
commit aff071a220
4 changed files with 595 additions and 1273 deletions

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@ -1,9 +1,10 @@
# $NetBSD: files.tmpfs,v 1.4 2010/06/22 18:32:07 rmind Exp $
# $NetBSD: files.tmpfs,v 1.5 2012/05/09 00:16:07 riastradh Exp $
deffs TMPFS
file fs/tmpfs/tmpfs_fifoops.c tmpfs
file fs/tmpfs/tmpfs_mem.c tmpfs
file fs/tmpfs/tmpfs_rename.c tmpfs
file fs/tmpfs/tmpfs_specops.c tmpfs
file fs/tmpfs/tmpfs_subr.c tmpfs
file fs/tmpfs/tmpfs_vfsops.c tmpfs

589
sys/fs/tmpfs/tmpfs_rename.c Normal file
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@ -0,0 +1,589 @@
/* $NetBSD: tmpfs_rename.c,v 1.1 2012/05/09 00:16:07 riastradh Exp $ */
/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Taylor R Campbell.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* tmpfs rename
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tmpfs_rename.c,v 1.1 2012/05/09 00:16:07 riastradh 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/vnode.h>
#include <sys/vnode_if.h>
#include <miscfs/genfs/genfs.h>
#include <fs/tmpfs/tmpfs_vnops.h>
#include <fs/tmpfs/tmpfs.h>
/*
* Forward declarations
*/
static int tmpfs_sane_rename(struct vnode *, struct componentname *,
struct vnode *, struct componentname *,
kauth_cred_t, bool);
static bool tmpfs_rmdired_p(struct vnode *);
static int tmpfs_gro_lock_directory(struct mount *, struct vnode *);
static const struct genfs_rename_ops tmpfs_genfs_rename_ops;
/*
* tmpfs_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
tmpfs_sane_rename(
struct vnode *fdvp, struct componentname *fcnp,
struct vnode *tdvp, struct componentname *tcnp,
kauth_cred_t cred, bool posixly_correct)
{
struct tmpfs_dirent *fdirent, *tdirent;
return genfs_sane_rename(&tmpfs_genfs_rename_ops,
fdvp, fcnp, &fdirent, tdvp, tcnp, &tdirent,
cred, posixly_correct);
}
/*
* tmpfs_rename: The hairiest vop, with the insanest API. Defer to
* genfs_insane_rename immediately.
*/
int
tmpfs_rename(void *v)
{
return genfs_insane_rename(v, &tmpfs_sane_rename);
}
/*
* tmpfs_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
tmpfs_gro_directory_empty_p(struct mount *mp, kauth_cred_t cred,
struct vnode *vp, struct vnode *dvp)
{
(void)mp;
(void)cred;
(void)dvp;
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);
return (VP_TO_TMPFS_NODE(vp)->tn_size == 0);
}
/*
* tmpfs_gro_rename_check_possible: Check whether a rename is possible
* independent of credentials.
*/
static int
tmpfs_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));
return genfs_ufslike_rename_check_possible(
VP_TO_TMPFS_NODE(fdvp)->tn_flags, VP_TO_TMPFS_NODE(fvp)->tn_flags,
VP_TO_TMPFS_NODE(tdvp)->tn_flags,
(tvp? VP_TO_TMPFS_NODE(tvp)->tn_flags : 0), (tvp != NULL),
IMMUTABLE, APPEND);
}
/*
* tmpfs_gro_rename_check_permitted: Check whether a rename is
* permitted given our credentials.
*/
static int
tmpfs_gro_rename_check_permitted(struct mount *mp, kauth_cred_t cred,
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));
return genfs_ufslike_rename_check_permitted(cred,
fdvp, VP_TO_TMPFS_NODE(fdvp)->tn_mode,
VP_TO_TMPFS_NODE(fdvp)->tn_uid,
fvp, VP_TO_TMPFS_NODE(fvp)->tn_uid,
tdvp, VP_TO_TMPFS_NODE(tdvp)->tn_mode,
VP_TO_TMPFS_NODE(tdvp)->tn_uid,
tvp, (tvp? VP_TO_TMPFS_NODE(tvp)->tn_uid : 0));
}
/*
* tmpfs_gro_remove_check_possible: Check whether a remove is possible
* independent of credentials.
*/
static int
tmpfs_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);
return genfs_ufslike_remove_check_possible(
VP_TO_TMPFS_NODE(dvp)->tn_flags, VP_TO_TMPFS_NODE(vp)->tn_flags,
IMMUTABLE, APPEND);
}
/*
* tmpfs_gro_remove_check_permitted: Check whether a remove is
* permitted given our credentials.
*/
static int
tmpfs_gro_remove_check_permitted(struct mount *mp, kauth_cred_t cred,
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);
return genfs_ufslike_remove_check_permitted(cred,
dvp, VP_TO_TMPFS_NODE(dvp)->tn_mode, VP_TO_TMPFS_NODE(dvp)->tn_uid,
vp, VP_TO_TMPFS_NODE(vp)->tn_uid);
}
/*
* tmpfs_gro_rename: Actually perform the rename operation.
*/
static int
tmpfs_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 tmpfs_dirent **fdep = fde;
struct tmpfs_dirent **tdep = tde;
char *newname;
(void)cred;
KASSERT(mp != NULL);
KASSERT(fdvp != NULL);
KASSERT(fcnp != NULL);
KASSERT(fdep != NULL);
KASSERT(fvp != NULL);
KASSERT(tdvp != NULL);
KASSERT(tcnp != NULL);
KASSERT(tdep != NULL);
KASSERT(fdep != tdep);
KASSERT((*fdep) != (*tdep));
KASSERT((*fdep) != NULL);
KASSERT((*fdep)->td_node == VP_TO_TMPFS_NODE(fvp));
KASSERT((tvp == NULL) || ((*tdep) != NULL));
KASSERT((tvp == NULL) || ((*tdep)->td_node == VP_TO_TMPFS_NODE(tvp)));
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));
if (tmpfs_strname_neqlen(fcnp, tcnp)) {
newname = tmpfs_strname_alloc(VFS_TO_TMPFS(mp),
tcnp->cn_namelen);
if (newname == NULL)
return ENOSPC;
} else {
newname = NULL;
}
/*
* If we are moving from one directory to another, detach the
* source entry and reattach it to the target directory.
*/
if (fdvp != tdvp) {
tmpfs_dir_detach(fdvp, *fdep);
tmpfs_dir_attach(tdvp, *fdep, VP_TO_TMPFS_NODE(fvp));
} else if (tvp == NULL) {
/*
* We are changing the directory. tmpfs_dir_attach and
* tmpfs_dir_detach note the events for us, but for
* this case we don't call them, so we must note the
* event explicitly.
*/
VN_KNOTE(fdvp, NOTE_WRITE);
}
/*
* If we are replacing an existing target entry, delete it.
*
* XXX What if the target is a directory with whiteout entries?
*/
if (tvp != NULL) {
KASSERT((*tdep) != NULL);
KASSERT((*tdep)->td_node == VP_TO_TMPFS_NODE(tvp));
KASSERT((fvp->v_type == VDIR) == (tvp->v_type == VDIR));
if (tvp->v_type == VDIR) {
KASSERT(VP_TO_TMPFS_NODE(tvp)->tn_size == 0);
KASSERT(VP_TO_TMPFS_NODE(tvp)->tn_links == 2);
/*
* Decrement the extra link count for `.' so
* the vnode will be recycled when released.
*
* XXX Why not just release directory vnodes
* when their link count is 1 instead of 0 in
* tmpfs_inactive, since `.' is being treated
* specially anyway?
*/
VP_TO_TMPFS_NODE(tvp)->tn_links--;
}
tmpfs_dir_detach(tdvp, *tdep);
tmpfs_free_dirent(VFS_TO_TMPFS(mp), *tdep);
}
/*
* Update the directory entry's name if necessary, and flag
* metadata updates. A memory allocation failure here is not
* OK because we've already committed some changes that we
* can't back out at this point, hence the early allocation
* above.
*/
if (newname != NULL) {
KASSERT(tcnp->cn_namelen <= TMPFS_MAXNAMLEN);
tmpfs_strname_free(VFS_TO_TMPFS(mp), (*fdep)->td_name,
(*fdep)->td_namelen);
(*fdep)->td_namelen = (uint16_t)tcnp->cn_namelen;
(void)memcpy(newname, tcnp->cn_nameptr, tcnp->cn_namelen);
(*fdep)->td_name = newname;
VP_TO_TMPFS_NODE(fvp)->tn_status |= TMPFS_NODE_CHANGED;
VP_TO_TMPFS_NODE(tdvp)->tn_status |= TMPFS_NODE_MODIFIED;
}
#if 0 /* XXX */
genfs_rename_cache_purge(fdvp, fvp, tdvp, tvp);
#endif
return 0;
}
/*
* tmpfs_gro_remove: Rename an object over another link to itself,
* effectively removing just the original link.
*/
static int
tmpfs_gro_remove(struct mount *mp, kauth_cred_t cred,
struct vnode *dvp, struct componentname *cnp, void *de, struct vnode *vp)
{
struct tmpfs_dirent **dep = de;
(void)vp;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(cnp != NULL);
KASSERT(dep != 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);
tmpfs_dir_detach(dvp, *dep);
tmpfs_free_dirent(VFS_TO_TMPFS(mp), *dep);
return 0;
}
/*
* tmpfs_gro_lookup: Look up and save the lookup results.
*/
static int
tmpfs_gro_lookup(struct mount *mp, struct vnode *dvp,
struct componentname *cnp, void *de_ret, struct vnode **vp_ret)
{
struct tmpfs_dirent *dirent, **dep_ret = de_ret;
struct vnode *vp;
int error;
(void)mp;
KASSERT(mp != NULL);
KASSERT(dvp != NULL);
KASSERT(cnp != NULL);
KASSERT(dep_ret != NULL);
KASSERT(vp_ret != NULL);
KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
dirent = tmpfs_dir_lookup(VP_TO_TMPFS_NODE(dvp), cnp);
if (dirent == NULL)
return ENOENT;
mutex_enter(&dirent->td_node->tn_vlock);
error = tmpfs_vnode_get(mp, dirent->td_node, &vp);
/* Note: tmpfs_vnode_get always releases dirent->td_node->tn_vlock. */
if (error)
return error;
KASSERT(vp != NULL);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
/*
* tmpfs_vnode_get returns this locked for us, which would be
* convenient but for lossage in other file systems. So, for
* hysterical raisins, we have to unlock it here. The caller
* will lock it again, and we don't rely on any interesting
* invariants in the interim, beyond that it won't vanish from
* under us, which it won't because it's referenced.
*
* XXX Once namei is fixed, we can change the genfs_rename
* protocol so that this unlock is not necessary.
*/
VOP_UNLOCK(vp);
*dep_ret = dirent;
*vp_ret = vp;
return 0;
}
/*
* tmpfs_rmdired_p: Check whether the directory vp has been rmdired.
*
* vp must be locked and referenced.
*/
static bool
tmpfs_rmdired_p(struct vnode *vp)
{
KASSERT(vp != NULL);
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
KASSERT(vp->v_type == VDIR);
return (VP_TO_TMPFS_NODE(vp)->tn_spec.tn_dir.tn_parent == NULL);
}
/*
* tmpfs_gro_genealogy: Analyze the genealogy of the source and target
* directories.
*/
static int
tmpfs_gro_genealogy(struct mount *mp, kauth_cred_t cred,
struct vnode *fdvp, struct vnode *tdvp,
struct vnode **intermediate_node_ret)
{
struct vnode *vp;
struct tmpfs_node *dnode;
int error;
(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);
/*
* We need to provisionally lock tdvp to keep rmdir from
* deleting it -- or any ancestor -- at an inopportune moment.
*/
error = tmpfs_gro_lock_directory(mp, tdvp);
if (error)
return error;
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(!tmpfs_rmdired_p(vp));
dnode = VP_TO_TMPFS_NODE(vp)->tn_spec.tn_dir.tn_parent;
/*
* If dnode is null then vp has been rmdir'd, which is
* not supposed to happen because we have it locked.
*/
KASSERT(dnode != NULL);
/* Did we hit the root without finding fdvp? */
if (dnode == VP_TO_TMPFS_NODE(vp)) {
vput(vp);
*intermediate_node_ret = NULL;
return 0;
}
/* Did we find that fdvp is an ancestor of tdvp? */
if (dnode == VP_TO_TMPFS_NODE(fdvp)) {
KASSERT(dnode->tn_vnode == fdvp);
/* Unlock vp, but keep it referenced. */
VOP_UNLOCK(vp);
*intermediate_node_ret = vp;
return 0;
}
/* Neither -- keep ascending the family tree. */
mutex_enter(&dnode->tn_vlock);
vput(vp);
vp = NULL; /* Just in case, for the kassert above... */
error = tmpfs_vnode_get(mp, dnode, &vp);
if (error)
return error;
}
}
/*
* tmpfs_gro_lock_directory: Lock the directory vp, but fail if it has
* been rmdir'd.
*/
static int
tmpfs_gro_lock_directory(struct mount *mp, struct vnode *vp)
{
(void)mp;
KASSERT(mp != NULL);
KASSERT(vp != NULL);
KASSERT(vp->v_mount == mp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (tmpfs_rmdired_p(vp)) {
VOP_UNLOCK(vp);
return ENOENT;
}
return 0;
}
static const struct genfs_rename_ops tmpfs_genfs_rename_ops = {
.gro_directory_empty_p = tmpfs_gro_directory_empty_p,
.gro_rename_check_possible = tmpfs_gro_rename_check_possible,
.gro_rename_check_permitted = tmpfs_gro_rename_check_permitted,
.gro_remove_check_possible = tmpfs_gro_remove_check_possible,
.gro_remove_check_permitted = tmpfs_gro_remove_check_permitted,
.gro_rename = tmpfs_gro_rename,
.gro_remove = tmpfs_gro_remove,
.gro_lookup = tmpfs_gro_lookup,
.gro_genealogy = tmpfs_gro_genealogy,
.gro_lock_directory = tmpfs_gro_lock_directory,
};

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@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.4 2010/06/22 18:32:08 rmind Exp $
# $NetBSD: Makefile,v 1.5 2012/05/09 00:16:07 riastradh Exp $
#
.PATH: ${.CURDIR}/../../../../fs/tmpfs
@ -6,7 +6,7 @@
LIB= rumpfs_tmpfs
SRCS= tmpfs_fifoops.c tmpfs_specops.c tmpfs_vfsops.c tmpfs_mem.c \
tmpfs_subr.c tmpfs_vnops.c
tmpfs_rename.c tmpfs_subr.c tmpfs_vnops.c
.include <bsd.lib.mk>
.include <bsd.klinks.mk>