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/*-
* Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/pseudofs/pseudofs_internal.h>
static MALLOC_DEFINE(M_PFSVNCACHE, "pfs_vncache", "pseudofs vnode cache");
static struct mtx pfs_vncache_mutex;
struct pfs_vnode {
struct vnode *pv_vnode;
struct pfs_vnode *pv_next;
} *pfs_vncache;
SYSCTL_NODE(_vfs_pfs, OID_AUTO, vncache, CTLFLAG_RW, 0,
"pseudofs vnode cache");
static int pfs_vncache_hits;
SYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, hits, CTLFLAG_RD, &pfs_vncache_hits, 0,
"number of cache hits since initialization");
static int pfs_vncache_misses;
SYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, misses, CTLFLAG_RD, &pfs_vncache_misses, 0,
"number of cache misses since initialization");
extern vop_t **pfs_vnodeop_p;
/*
* Initialize vnode cache
*/
void
pfs_vncache_load(void)
{
mtx_init(&pfs_vncache_mutex, "pseudofs_vncache", MTX_DEF);
}
/*
* Tear down vnode cache
*/
void
pfs_vncache_unload(void)
{
mtx_destroy(&pfs_vncache_mutex);
}
/*
* Allocate a vnode
*/
int
pfs_vncache_alloc(struct mount *mp, struct vnode **vpp,
struct pfs_node *pn, pid_t pid)
{
struct pfs_vnode *pv;
struct pfs_vdata *pvd;
int error;
/* see if the vnode is in the cache */
mtx_lock(&pfs_vncache_mutex);
for (pv = pfs_vncache; pv; pv = pv->pv_next) {
pvd = (struct pfs_vdata *)pv->pv_vnode->v_data;
if (pvd->pvd_pn == pn && pvd->pvd_pid == pid) {
if (vget(pv->pv_vnode, 0, curproc) == 0) {
++pfs_vncache_hits;
*vpp = pv->pv_vnode;
mtx_unlock(&pfs_vncache_mutex);
return (0);
}
/* XXX if this can happen, we're in trouble */
break;
}
}
mtx_unlock(&pfs_vncache_mutex);
++pfs_vncache_misses;
/* nope, get a new one */
MALLOC(pv, struct pfs_vnode *, sizeof *pv, M_PFSVNCACHE, M_WAITOK);
MALLOC(pvd, struct pfs_vdata *, sizeof *pvd, M_PFSVNCACHE, M_WAITOK);
error = getnewvnode(VT_PSEUDOFS, mp, pfs_vnodeop_p, vpp);
if (error)
return (error);
pvd->pvd_pn = pn;
pvd->pvd_pid = pid;
(*vpp)->v_data = pvd;
switch (pn->pn_type) {
case pfstype_root:
(*vpp)->v_flag = VROOT;
#if 0
printf("root vnode allocated\n");
#endif
case pfstype_dir:
case pfstype_this:
case pfstype_parent:
case pfstype_procdir:
(*vpp)->v_type = VDIR;
break;
case pfstype_file:
(*vpp)->v_type = VREG;
break;
case pfstype_symlink:
(*vpp)->v_type = VLNK;
break;
case pfstype_none:
KASSERT(0, ("pfs_vncache_alloc called for null node\n"));
default:
panic("%s has unexpected type: %d", pn->pn_name, pn->pn_type);
}
pv->pv_vnode = *vpp;
mtx_lock(&pfs_vncache_mutex);
pv->pv_next = pfs_vncache;
pfs_vncache = pv;
mtx_unlock(&pfs_vncache_mutex);
return (0);
}
/*
* Free a vnode
*/
int
pfs_vncache_free(struct vnode *vp)
{
struct pfs_vnode *prev, *pv;
struct pfs_vdata *pvd;
mtx_lock(&pfs_vncache_mutex);
for (prev = NULL, pv = pfs_vncache; pv; prev = pv, pv = pv->pv_next)
if (pv->pv_vnode == vp)
break;
KASSERT(pv != NULL, ("pfs_vncache_free(): not in cache\n"));
if (prev)
prev->pv_next = pv->pv_next;
else
pfs_vncache = pv->pv_next;
mtx_unlock(&pfs_vncache_mutex);
pvd = (struct pfs_vdata *)vp->v_data;
FREE(pvd, M_PFSVNCACHE);
vp->v_data = NULL;
FREE(pv, M_PFSVNCACHE);
return (0);
}
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