1 /*- 2 * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/systm.h> 34 #include <sys/lock.h> 35 #include <sys/malloc.h> 36 #include <sys/mount.h> 37 #include <sys/mutex.h> 38 #include <sys/sbuf.h> 39 #include <sys/sysctl.h> 40 #include <sys/vnode.h> 41 42 #include <fs/pseudofs/pseudofs.h> 43 #include <fs/pseudofs/pseudofs_internal.h> 44 45 static MALLOC_DEFINE(M_PFSVNCACHE, "pfs_vncache", "pseudofs vnode cache"); 46 47 static struct mtx pfs_vncache_mutex; 48 49 struct pfs_vnode { 50 struct vnode *pv_vnode; 51 struct pfs_vnode *pv_next; 52 } *pfs_vncache; 53 54 SYSCTL_NODE(_vfs_pfs, OID_AUTO, vncache, CTLFLAG_RW, 0, 55 "pseudofs vnode cache"); 56 57 static int pfs_vncache_hits; 58 SYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, hits, CTLFLAG_RD, &pfs_vncache_hits, 0, 59 "number of cache hits since initialization"); 60 61 static int pfs_vncache_misses; 62 SYSCTL_INT(_vfs_pfs_vncache, OID_AUTO, misses, CTLFLAG_RD, &pfs_vncache_misses, 0, 63 "number of cache misses since initialization"); 64 65 extern vop_t **pfs_vnodeop_p; 66 67 /* 68 * Initialize vnode cache 69 */ 70 void 71 pfs_vncache_load(void) 72 { 73 mtx_init(&pfs_vncache_mutex, "pseudofs_vncache", MTX_DEF); 74 } 75 76 /* 77 * Tear down vnode cache 78 */ 79 void 80 pfs_vncache_unload(void) 81 { 82 mtx_destroy(&pfs_vncache_mutex); 83 } 84 85 /* 86 * Allocate a vnode 87 */ 88 int 89 pfs_vncache_alloc(struct mount *mp, struct vnode **vpp, 90 struct pfs_node *pn, pid_t pid) 91 { 92 struct pfs_vnode *pv; 93 struct pfs_vdata *pvd; 94 int error; 95 96 /* see if the vnode is in the cache */ 97 mtx_lock(&pfs_vncache_mutex); 98 for (pv = pfs_vncache; pv; pv = pv->pv_next) { 99 pvd = (struct pfs_vdata *)pv->pv_vnode->v_data; 100 if (pvd->pvd_pn == pn && pvd->pvd_pid == pid) { 101 if (vget(pv->pv_vnode, 0, curproc) == 0) { 102 ++pfs_vncache_hits; 103 *vpp = pv->pv_vnode; 104 mtx_unlock(&pfs_vncache_mutex); 105 return (0); 106 } 107 /* XXX if this can happen, we're in trouble */ 108 break; 109 } 110 } 111 mtx_unlock(&pfs_vncache_mutex); 112 ++pfs_vncache_misses; 113 114 /* nope, get a new one */ 115 MALLOC(pv, struct pfs_vnode *, sizeof *pv, M_PFSVNCACHE, M_WAITOK); 116 MALLOC(pvd, struct pfs_vdata *, sizeof *pvd, M_PFSVNCACHE, M_WAITOK); 117 error = getnewvnode(VT_PSEUDOFS, mp, pfs_vnodeop_p, vpp); 118 if (error) 119 return (error); 120 pvd->pvd_pn = pn; 121 pvd->pvd_pid = pid; 122 (*vpp)->v_data = pvd; 123 switch (pn->pn_type) { 124 case pfstype_root: 125 (*vpp)->v_flag = VROOT; 126 #if 0 127 printf("root vnode allocated\n"); 128 #endif 129 case pfstype_dir: 130 case pfstype_this: 131 case pfstype_parent: 132 case pfstype_procdir: 133 (*vpp)->v_type = VDIR; 134 break; 135 case pfstype_file: 136 (*vpp)->v_type = VREG; 137 break; 138 case pfstype_symlink: 139 (*vpp)->v_type = VLNK; 140 break; 141 case pfstype_none: 142 KASSERT(0, ("pfs_vncache_alloc called for null node\n")); 143 default: 144 panic("%s has unexpected type: %d", pn->pn_name, pn->pn_type); 145 } 146 pv->pv_vnode = *vpp; 147 mtx_lock(&pfs_vncache_mutex); 148 pv->pv_next = pfs_vncache; 149 pfs_vncache = pv; 150 mtx_unlock(&pfs_vncache_mutex); 151 return (0); 152 } 153 154 /* 155 * Free a vnode 156 */ 157 int 158 pfs_vncache_free(struct vnode *vp) 159 { 160 struct pfs_vnode *prev, *pv; 161 struct pfs_vdata *pvd; 162 163 mtx_lock(&pfs_vncache_mutex); 164 for (prev = NULL, pv = pfs_vncache; pv; prev = pv, pv = pv->pv_next) 165 if (pv->pv_vnode == vp) 166 break; 167 KASSERT(pv != NULL, ("pfs_vncache_free(): not in cache\n")); 168 if (prev) 169 prev->pv_next = pv->pv_next; 170 else 171 pfs_vncache = pv->pv_next; 172 mtx_unlock(&pfs_vncache_mutex); 173 174 pvd = (struct pfs_vdata *)vp->v_data; 175 FREE(pvd, M_PFSVNCACHE); 176 vp->v_data = NULL; 177 FREE(pv, M_PFSVNCACHE); 178 return (0); 179 } 180