nfs4_shadow.c revision bbf2a467fb32eb69d2254866ccab51e89829ff38
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * CDDL HEADER START
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * The contents of this file are subject to the terms of the
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Common Development and Distribution License (the "License").
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * You may not use this file except in compliance with the License.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * or http://www.opensolaris.org/os/licensing.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * See the License for the specific language governing permissions
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * and limitations under the License.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * When distributing Covered Code, include this CDDL HEADER in each
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * If applicable, add the following below this CDDL HEADER, with the
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1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * information: Portions Copyright [yyyy] [name of copyright owner]
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * CDDL HEADER END
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * Use is subject to license terms.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <sys/systm.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <sys/cmn_err.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <nfs/nfs.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <nfs/nfs4.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <nfs/rnode4.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <nfs/nfs4_clnt.h>
678453a8ed49104d8adad58f3ba591bdc39883e8speer
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostatic struct kmem_cache *svnode_cache;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct sv_stats
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo int sv_activate;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo int sv_find;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo int sv_match;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo int sv_inactive;
678453a8ed49104d8adad58f3ba591bdc39883e8speer int sv_exchange;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna} sv_stats;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostatic int sv_match(nfs4_fname_t *, nfs4_sharedfh_t *, svnode_t *);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Map a vnode back to the shadow which points to it. This is
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * hard now that the vnode is not embedded in the shadow vnode.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
17cadca83cc82e37ff517ea2783eb4bfcc07b950lm
17cadca83cc82e37ff517ea2783eb4bfcc07b950lmsvnode_t *
17cadca83cc82e37ff517ea2783eb4bfcc07b950lmvtosv(vnode_t *vp)
17cadca83cc82e37ff517ea2783eb4bfcc07b950lm{
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna rnode4_t *rp = VTOR4(vp);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna svnode_t *svp, *svp_found = NULL;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna /* Check to see if it's the master shadow vnode first. */
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna if (RTOV4(rp) == vp)
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna return (&rp->r_svnode);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna mutex_enter(&rp->r_svlock);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna for (svp = rp->r_svnode.sv_forw; svp != &rp->r_svnode;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna svp = svp->sv_forw)
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna if (svp->sv_r_vnode == vp) {
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna svp_found = svp;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna break;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna }
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna mutex_exit(&rp->r_svlock);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna ASSERT(svp_found != NULL);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna return (svp_found);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * sv_activate - find and activate the shadow vnode for the given
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * directory file handle and name. May replace *vpp with a held reference
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * to a different vnode, in which case the reference to the previous one is
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * released.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatnavoid
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatnasv_activate(vnode_t **vpp, vnode_t *dvp, nfs4_fname_t **namepp, int newnode)
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo svnode_t *svp;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo vnode_t *resvp;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo rnode4_t *rp = VTOR4(*vpp);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo svp = VTOSV(*vpp);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna ASSERT(namepp != NULL);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo ASSERT(*namepp != NULL);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo ASSERT(dvp != NULL);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo sv_stats.sv_activate++;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo ASSERT(RW_LOCK_HELD(&rp->r_hashq->r_lock));
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo /*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * If make_rnode made a new rnode (ie. newnode != 0), then
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * the master vnode was (partially) initialized there. If
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * it was not a new rnode, then it returns the master vnode.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Call sv_find to find and/or initialize the shadow
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * vnode.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo if (newnode) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo /*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Initialize the shadow vnode.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo svp->sv_forw = svp->sv_back = svp;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo ASSERT(svp->sv_dfh == NULL);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo svp->sv_dfh = VTOR4(dvp)->r_fh;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo sfh4_hold(svp->sv_dfh);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna ASSERT(svp->sv_name == NULL);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna svp->sv_name = *namepp;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna } else if ((*vpp)->v_type == VREG && !((*vpp)->v_flag & VROOT)) {
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna resvp = sv_find(*vpp, dvp, namepp);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna ASSERT(resvp->v_type == VREG);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna VN_RELE(*vpp);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna *vpp = resvp;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna } else if ((*vpp)->v_type == VDIR) {
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna /*
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * Directories only have a single shadow vnode which
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * is the master shadow vnode. This is because directories
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * can't have hard links. If sv_activate() is
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * called for an existing rnode (newnode isn't set)
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * but with a new name the fname needs to be updated
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * and the old one released.
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna *
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * fname mismatches can occur due to server side renames,
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * here is a chance to update the fname in case there is
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * a mismatch. Since this is not a newnode we hold r_svlock
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * to protect sv_name.
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna */
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna mutex_enter(&rp->r_svlock);
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna nfs4_fname_t *svpname = svp->sv_name;
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna if (svpname != *namepp) {
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna /*
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * Call fn_rele() to release the hold for the
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * previous shadow vnode reference. Don't
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * release the hold on the fname pointed to by
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * namepp as we have new reference to it from
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna * this shadow vnode.
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna */
1107ea9346159bcc8ea154084897667347c4e6d5Sriharsha Basavapatna svp->sv_name = *namepp;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo mutex_exit(&rp->r_svlock);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo fn_rele(&svpname);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo } else {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo mutex_exit(&rp->r_svlock);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo fn_rele(namepp);
}
} else {
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);
}