freebsd-src/sys/fs/pseudofs/pseudofs_vncache.c
Dag-Erling Smørgrav 9733a80839 Let pseudofs into the warmth of the FreeBSD CVS repo.
It's not finished yet (I still have to find a way to implement process-
dependent nodes without consuming too much memory, and the permission
system needs tightening up), but it's becoming hard to work on without
a repo (I've accidentally almost nuked it once already), and it works
(except for the lack of process-dependent nodes, that is).

I was supposed to commit this a week ago, but timed out waiting for jkh
to reply to some questions I had. Pass him a spoonful of bad karma :)
2001-04-07 19:51:12 +00:00

169 lines
4.4 KiB
C

/*-
* 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/malloc.h>
#include <sys/mount.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, "pseudofs_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)
{
struct pfs_vnode *pv;
int error;
mtx_lock(&pfs_vncache_mutex);
/* see if the vnode is in the cache */
for (pv = pfs_vncache; pv; pv = pv->pv_next)
if (pv->pv_vnode->v_data == pn)
if (vget(pv->pv_vnode, 0, curproc) == 0) {
++pfs_vncache_hits;
*vpp = pv->pv_vnode;
mtx_unlock(&pfs_vncache_mutex);
return (0);
}
++pfs_vncache_misses;
/* nope, get a new one */
MALLOC(pv, struct pfs_vnode *, sizeof *pv, M_PFSVNCACHE, M_WAITOK);
error = getnewvnode(VT_PSEUDOFS, mp, pfs_vnodeop_p, vpp);
if (error) {
mtx_unlock(&pfs_vncache_mutex);
return (error);
}
(*vpp)->v_data = pn;
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:
(*vpp)->v_type = VDIR;
break;
case pfstype_file:
(*vpp)->v_type = VREG;
break;
case pfstype_symlink:
(*vpp)->v_type = VLNK;
break;
default:
panic("%s has unexpected type: %d", pn->pn_name, pn->pn_type);
}
pv->pv_vnode = *vpp;
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;
mtx_lock(&pfs_vncache_mutex);
for (prev = NULL, pv = pfs_vncache; pv; prev = pv, pv = pv->pv_next)
if (pv->pv_vnode == vp)
break;
if (!pv)
printf("pfs_vncache_free(): not in cache\n"); /* it should be! */
#if 0
if (vp->v_data == ((struct pfs_info *)vp->v_mount->mnt_data)->pi_root)
printf("root vnode reclaimed\n");
#endif
vp->v_data = NULL;
if (pv) {
if (prev)
prev->pv_next = pv->pv_next;
else
pfs_vncache = pv->pv_next;
FREE(pv, M_PFSVNCACHE);
}
mtx_unlock(&pfs_vncache_mutex);
return (0);
}