pseudofs_vncache.c revision 75295
175295Sdes/*- 275295Sdes * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav 375295Sdes * All rights reserved. 475295Sdes * 575295Sdes * Redistribution and use in source and binary forms, with or without 675295Sdes * modification, are permitted provided that the following conditions 775295Sdes * are met: 875295Sdes * 1. Redistributions of source code must retain the above copyright 975295Sdes * notice, this list of conditions and the following disclaimer 1075295Sdes * in this position and unchanged. 1175295Sdes * 2. Redistributions in binary form must reproduce the above copyright 1275295Sdes * notice, this list of conditions and the following disclaimer in the 1375295Sdes * documentation and/or other materials provided with the distribution. 1475295Sdes * 3. The name of the author may not be used to endorse or promote products 1575295Sdes * derived from this software without specific prior written permission. 1675295Sdes * 1775295Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1875295Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1975295Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 2075295Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 2175295Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2275295Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2375295Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2475295Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2575295Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2675295Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2775295Sdes * 2875295Sdes * $FreeBSD: head/sys/fs/pseudofs/pseudofs_vncache.c 75295 2001-04-07 19:51:12Z des $ 2975295Sdes */ 3075295Sdes 3175295Sdes#include <sys/param.h> 3275295Sdes#include <sys/kernel.h> 3375295Sdes#include <sys/systm.h> 3475295Sdes#include <sys/malloc.h> 3575295Sdes#include <sys/mount.h> 3675295Sdes#include <sys/sbuf.h> 3775295Sdes#include <sys/sysctl.h> 3875295Sdes#include <sys/vnode.h> 3975295Sdes 4075295Sdes#include <fs/pseudofs/pseudofs.h> 4175295Sdes#include <fs/pseudofs/pseudofs_internal.h> 4275295Sdes 4375295Sdesstatic MALLOC_DEFINE(M_PFSVNCACHE, "pseudofs_vncache", "pseudofs vnode cache"); 4475295Sdes 4575295Sdesstatic struct mtx pfs_vncache_mutex; 4675295Sdes 4775295Sdesstruct pfs_vnode { 4875295Sdes struct vnode *pv_vnode; 4975295Sdes struct pfs_vnode *pv_next; 5075295Sdes} *pfs_vncache; 5175295Sdes 5275295SdesSYSCTL_NODE(_vfs_pfs, OID_AUTO, vncache, CTLFLAG_RW, 0, 5375295Sdes "pseudofs vnode cache"); 5475295Sdes 5575295Sdesstatic int pfs_vncache_hits; 5675295SdesSYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, hits, CTLFLAG_RD, &pfs_vncache_hits, 0, 5775295Sdes "number of cache hits since initialization"); 5875295Sdes 5975295Sdesstatic int pfs_vncache_misses; 6075295SdesSYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, misses, CTLFLAG_RD, &pfs_vncache_misses, 0, 6175295Sdes "number of cache misses since initialization"); 6275295Sdes 6375295Sdesextern vop_t **pfs_vnodeop_p; 6475295Sdes 6575295Sdes/* 6675295Sdes * Initialize vnode cache 6775295Sdes */ 6875295Sdesvoid 6975295Sdespfs_vncache_load(void) 7075295Sdes{ 7175295Sdes mtx_init(&pfs_vncache_mutex, "pseudofs_vncache", MTX_DEF); 7275295Sdes} 7375295Sdes 7475295Sdes/* 7575295Sdes * Tear down vnode cache 7675295Sdes */ 7775295Sdesvoid 7875295Sdespfs_vncache_unload(void) 7975295Sdes{ 8075295Sdes mtx_destroy(&pfs_vncache_mutex); 8175295Sdes} 8275295Sdes 8375295Sdes/* 8475295Sdes * Allocate a vnode 8575295Sdes */ 8675295Sdesint 8775295Sdespfs_vncache_alloc(struct mount *mp, struct vnode **vpp, struct pfs_node *pn) 8875295Sdes{ 8975295Sdes struct pfs_vnode *pv; 9075295Sdes int error; 9175295Sdes 9275295Sdes mtx_lock(&pfs_vncache_mutex); 9375295Sdes 9475295Sdes /* see if the vnode is in the cache */ 9575295Sdes for (pv = pfs_vncache; pv; pv = pv->pv_next) 9675295Sdes if (pv->pv_vnode->v_data == pn) 9775295Sdes if (vget(pv->pv_vnode, 0, curproc) == 0) { 9875295Sdes ++pfs_vncache_hits; 9975295Sdes *vpp = pv->pv_vnode; 10075295Sdes mtx_unlock(&pfs_vncache_mutex); 10175295Sdes return (0); 10275295Sdes } 10375295Sdes ++pfs_vncache_misses; 10475295Sdes 10575295Sdes /* nope, get a new one */ 10675295Sdes MALLOC(pv, struct pfs_vnode *, sizeof *pv, M_PFSVNCACHE, M_WAITOK); 10775295Sdes error = getnewvnode(VT_PSEUDOFS, mp, pfs_vnodeop_p, vpp); 10875295Sdes if (error) { 10975295Sdes mtx_unlock(&pfs_vncache_mutex); 11075295Sdes return (error); 11175295Sdes } 11275295Sdes (*vpp)->v_data = pn; 11375295Sdes switch (pn->pn_type) { 11475295Sdes case pfstype_root: 11575295Sdes (*vpp)->v_flag = VROOT; 11675295Sdes#if 0 11775295Sdes printf("root vnode allocated\n"); 11875295Sdes#endif 11975295Sdes case pfstype_dir: 12075295Sdes case pfstype_this: 12175295Sdes case pfstype_parent: 12275295Sdes (*vpp)->v_type = VDIR; 12375295Sdes break; 12475295Sdes case pfstype_file: 12575295Sdes (*vpp)->v_type = VREG; 12675295Sdes break; 12775295Sdes case pfstype_symlink: 12875295Sdes (*vpp)->v_type = VLNK; 12975295Sdes break; 13075295Sdes default: 13175295Sdes panic("%s has unexpected type: %d", pn->pn_name, pn->pn_type); 13275295Sdes } 13375295Sdes pv->pv_vnode = *vpp; 13475295Sdes pv->pv_next = pfs_vncache; 13575295Sdes pfs_vncache = pv; 13675295Sdes mtx_unlock(&pfs_vncache_mutex); 13775295Sdes return (0); 13875295Sdes} 13975295Sdes 14075295Sdes/* 14175295Sdes * Free a vnode 14275295Sdes */ 14375295Sdesint 14475295Sdespfs_vncache_free(struct vnode *vp) 14575295Sdes{ 14675295Sdes struct pfs_vnode *prev, *pv; 14775295Sdes 14875295Sdes mtx_lock(&pfs_vncache_mutex); 14975295Sdes for (prev = NULL, pv = pfs_vncache; pv; prev = pv, pv = pv->pv_next) 15075295Sdes if (pv->pv_vnode == vp) 15175295Sdes break; 15275295Sdes if (!pv) 15375295Sdes printf("pfs_vncache_free(): not in cache\n"); /* it should be! */ 15475295Sdes#if 0 15575295Sdes if (vp->v_data == ((struct pfs_info *)vp->v_mount->mnt_data)->pi_root) 15675295Sdes printf("root vnode reclaimed\n"); 15775295Sdes#endif 15875295Sdes vp->v_data = NULL; 15975295Sdes if (pv) { 16075295Sdes if (prev) 16175295Sdes prev->pv_next = pv->pv_next; 16275295Sdes else 16375295Sdes pfs_vncache = pv->pv_next; 16475295Sdes FREE(pv, M_PFSVNCACHE); 16575295Sdes } 16675295Sdes mtx_unlock(&pfs_vncache_mutex); 16775295Sdes return (0); 16875295Sdes} 169