/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/systm.h>
#include <sys/cmn_err.h>
#include <nfs/nfs.h>
#include <nfs/nfs4.h>
#include <nfs/rnode4.h>
#include <nfs/nfs4_clnt.h>
static struct kmem_cache *svnode_cache;
struct sv_stats
{
int sv_activate;
int sv_find;
int sv_match;
int sv_inactive;
int sv_exchange;
} sv_stats;
static int sv_match(nfs4_fname_t *, nfs4_sharedfh_t *, svnode_t *);
/*
* Map a vnode back to the shadow which points to it. This is
* hard now that the vnode is not embedded in the shadow vnode.
*/
svnode_t *
vtosv(vnode_t *vp)
{
rnode4_t *rp = VTOR4(vp);
svnode_t *svp, *svp_found = NULL;
/* Check to see if it's the master shadow vnode first. */
if (RTOV4(rp) == vp)
return (&rp->r_svnode);
mutex_enter(&rp->r_svlock);
for (svp = rp->r_svnode.sv_forw; svp != &rp->r_svnode;
svp = svp->sv_forw)
if (svp->sv_r_vnode == vp) {
svp_found = svp;
break;
}
mutex_exit(&rp->r_svlock);
ASSERT(svp_found != NULL);
return (svp_found);
}
/*
* sv_activate - find and activate the shadow vnode for the given
* directory file handle and name. May replace *vpp with a held reference
* to a different vnode, in which case the reference to the previous one is
* released.
*/
void
sv_activate(vnode_t **vpp, vnode_t *dvp, nfs4_fname_t **namepp, int newnode)
{
svnode_t *svp;
vnode_t *resvp;
nfs4_fname_t *svpname;
rnode4_t *rp = VTOR4(*vpp);
svp = VTOSV(*vpp);
ASSERT(namepp != NULL);
ASSERT(*namepp != NULL);
ASSERT(dvp != NULL);
sv_stats.sv_activate++;
ASSERT(RW_LOCK_HELD(&rp->r_hashq->r_lock));
/*
* If make_rnode made a new rnode (ie. newnode != 0), then
* the master vnode was (partially) initialized there. If
* it was not a new rnode, then it returns the master vnode.
* Call sv_find to find and/or initialize the shadow
* vnode.
*/
if (newnode) {
/*
* Initialize the shadow vnode.
*/
svp->sv_forw = svp->sv_back = svp;
ASSERT(svp->sv_dfh == NULL);
svp->sv_dfh = VTOR4(dvp)->r_fh;
sfh4_hold(svp->sv_dfh);
ASSERT(svp->sv_name == NULL);
svp->sv_name = *namepp;
} else if ((*vpp)->v_type == VREG && !((*vpp)->v_flag & VROOT)) {
resvp = sv_find(*vpp, dvp, namepp);
ASSERT(resvp->v_type == VREG);
VN_RELE(*vpp);
*vpp = resvp;
} else {
/*
* No shadow vnodes (i.e. hard links) in this branch.
* If sv_activate() is called for an existing rnode
* (newnode isn't set) but with a new name, the sv_name
* needs to be updated and the old sv_name released.
*
* fname mismatches can occur due to server side renames,
* here is a chance to update the fname in case there is
* a mismatch. Since this is not a newnode we hold r_svlock
* to protect sv_name.
*/
mutex_enter(&rp->r_svlock);
svpname = svp->sv_name;
if (svpname != *namepp) {
/*
* Call fn_rele() to release the hold for the
* previous shadow vnode reference. Don't
* release the hold on the fname pointed to by
* namepp as we have new reference to it from
* this shadow vnode.
*/
svp->sv_name = *namepp;
mutex_exit(&rp->r_svlock);
fn_rele(&svpname);
} else {
mutex_exit(&rp->r_svlock);
fn_rele(namepp);
}
}
}
/*
* sv_find - find the shadow vnode for the desired name and directory
* file handle. If one does not exist, then create it. Returns the shadow
* vnode. The caller is responsible for freeing the reference.
* Consumes the name reference and nulls it out.
*
* Side effects: increments the reference count on the master vnode if the
* shadow vnode had to be created.
*/
vnode_t *
sv_find(vnode_t *mvp, vnode_t *dvp, nfs4_fname_t **namepp)
{
vnode_t *vp;
rnode4_t *rp = VTOR4(mvp);
svnode_t *svp;
svnode_t *master_svp = VTOSV(mvp);
rnode4_t *drp = VTOR4(dvp);
nfs4_fname_t *nm;
ASSERT(dvp != NULL);
sv_stats.sv_find++;
ASSERT(namepp != NULL);
ASSERT(*namepp != NULL);
nm = *namepp;
*namepp = NULL;
/*
* At this point, all we know is that we have an rnode whose
* file handle matches the file handle of the object we want.
* We have to verify that component name and the directory
* match. If so, then we are done.
*
* Note: mvp is always the master vnode.
*/
ASSERT(!IS_SHADOW(mvp, rp));
if (sv_match(nm, drp->r_fh, master_svp)) {
VN_HOLD(mvp);
fn_rele(&nm);
return (mvp);
}
/*
* No match, search through the shadow vnode list.
* Hold the r_svlock to prevent changes.
*/
mutex_enter(&rp->r_svlock);
for (svp = master_svp->sv_forw; svp != master_svp; svp = svp->sv_forw)
if (sv_match(nm, drp->r_fh, svp)) {
/*
* A matching shadow vnode is found, bump the
* reference count on it and return it.
*/
vp = SVTOV(svp);
VN_HOLD(vp);
fn_rele(&nm);
mutex_exit(&rp->r_svlock);
return (vp);
}
/*
* No match searching the list, go allocate a new shadow
*/
svp = kmem_cache_alloc(svnode_cache, KM_SLEEP);
svp->sv_r_vnode = vn_alloc(KM_SLEEP);
vp = SVTOV(svp);
/* Initialize the vnode */
vn_setops(vp, nfs4_vnodeops);
vp->v_data = (caddr_t)rp;
vp->v_vfsp = mvp->v_vfsp;
ASSERT(nfs4_consistent_type(mvp));
vp->v_type = mvp->v_type;
vp->v_pages = (page_t *)-1; /* No pages, please */
vn_exists(vp);
/* Initialize the shadow vnode */
svp->sv_dfh = VTOR4(dvp)->r_fh;
sfh4_hold(svp->sv_dfh);
svp->sv_name = nm;
VN_HOLD(mvp);
insque(svp, master_svp);
mutex_exit(&rp->r_svlock);
return (vp);
}
/*
* sv_match - check to see if the shadow vnode matches the desired
* name and directory file handle. Returns non-zero if there's a match,
* zero if it's not a match.
*/
static int
sv_match(nfs4_fname_t *nm, nfs4_sharedfh_t *fhp, svnode_t *svp)
{
sv_stats.sv_match++;
return (svp->sv_name != NULL && svp->sv_name == nm &&
SFH4_SAME(svp->sv_dfh, fhp));
}
/*
* sv_inactive - deactivate a shadow vnode. sv_inactive is called
* from nfs4_inactive. Whenever a shadow vnode is de-activated,
* sv_inactive cleans up the mess and releases the reference on the
* master vnode.
*/
void
sv_inactive(vnode_t *vp)
{
svnode_t *svp;
rnode4_t *rp;
vnode_t *mvp;
sv_stats.sv_inactive++;
svp = VTOSV(vp);
rp = VTOR4(vp);
mvp = rp->r_vnode;
ASSERT(mvp != vp);
/*
* Remove the shadow vnode from the list. The serialization
* is provided by the svnode list lock. This could be done
* with the r_statelock, but that would require more locking
* in the activation path.
*/
mutex_enter(&rp->r_svlock);
mutex_enter(&vp->v_lock);
/* check if someone slipped in while locks were dropped */
if (vp->v_count > 1) {
vp->v_count--;
mutex_exit(&vp->v_lock);
mutex_exit(&rp->r_svlock);
return;
}
remque(svp);
mutex_exit(&vp->v_lock);
mutex_exit(&rp->r_svlock);
sv_uninit(svp);
svp->sv_forw = svp->sv_back = NULL;
kmem_cache_free(svnode_cache, svp);
vn_invalid(vp);
vn_free(vp);
/* release the reference held by this shadow on the master */
VN_RELE(mvp);
}
/*
* sv_uninit - free any data structures allocated by the shadow vnode.
*/
void
sv_uninit(svnode_t *svp)
{
if (svp->sv_name != NULL)
fn_rele(&svp->sv_name);
if (svp->sv_dfh != NULL)
sfh4_rele(&svp->sv_dfh);
}
/*
* sv_exchange - exchange a shadow vnode for the master vnode. This
* occurs during nfs4_open, since only the master vnode owns the files
* resources (eg. pages).
*/
void
sv_exchange(vnode_t **vpp)
{
vnode_t *mvp;
sv_stats.sv_exchange++;
/* RTOV always returns the master vnode */
mvp = RTOV4(VTOR4(*vpp));
VN_HOLD(mvp)
VN_RELE(*vpp);
*vpp = mvp;
}
int
nfs4_shadow_init(void)
{
/*
* Allocate shadow vnode cache
*/
svnode_cache = kmem_cache_create("svnode_cache",
sizeof (svnode_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
return (0);
}
int
nfs4_shadow_fini(void)
{
kmem_cache_destroy(svnode_cache);
return (0);
}