/* * Copyright (c) 2002 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995 * The Regents of the University of California. 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. * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. * * @(#)hfs_chash.c * derived from @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/vnode.h> #include <sys/malloc.h> #include <sys/proc.h> #include <sys/queue.h> #include "hfs_cnode.h" /* * Structures associated with cnode caching. */ LIST_HEAD(cnodehashhead, cnode) *cnodehashtbl; u_long cnodehash; /* size of hash table - 1 */ #define CNODEHASH(device, inum) (&cnodehashtbl[((device) + (inum)) & cnodehash]) struct slock hfs_chash_slock; /* * Initialize cnode hash table. */ __private_extern__ void hfs_chashinit() { cnodehashtbl = hashinit(desiredvnodes, M_HFSMNT, &cnodehash); simple_lock_init(&hfs_chash_slock); } /* * Use the device, inum pair to find the incore cnode. * * If it is in core, but locked, wait for it. * * If the requested vnode (fork) is not available, then * take a reference on the other vnode (fork) so that * the upcoming getnewvnode can not aquire it. */ __private_extern__ struct cnode * hfs_chashget(dev_t dev, ino_t inum, int wantrsrc, struct vnode **vpp, struct vnode **rvpp) { struct proc *p = current_proc(); struct cnode *cp; struct vnode *vp; int error; *vpp = NULLVP; *rvpp = NULLVP; /* * Go through the hash list * If a cnode is in the process of being cleaned out or being * allocated, wait for it to be finished and then try again. */ loop: simple_lock(&hfs_chash_slock); for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { if ((cp->c_fileid != inum) || (cp->c_dev != dev)) continue; if (ISSET(cp->c_flag, C_ALLOC)) { /* * cnode is being created. Wait for it to finish. */ SET(cp->c_flag, C_WALLOC); simple_unlock(&hfs_chash_slock); (void) tsleep((caddr_t)cp, PINOD, "hfs_chashget-1", 0); goto loop; } if (ISSET(cp->c_flag, C_TRANSIT)) { /* * cnode is getting reclaimed wait for * the operation to complete and return * error */ SET(cp->c_flag, C_WTRANSIT); simple_unlock(&hfs_chash_slock); (void)tsleep((caddr_t)cp, PINOD, "hfs_chashget-2", 0); goto loop; } if (cp->c_flag & C_NOEXISTS) continue; /* * Try getting the desired vnode first. If * it isn't available then take a reference * on the other vnode. */ vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; if (vp == NULLVP) vp = wantrsrc ? cp->c_vp : cp->c_rsrc_vp; if (vp == NULLVP) panic("hfs_chashget: orphaned cnode in hash"); simple_lock(&vp->v_interlock); simple_unlock(&hfs_chash_slock); if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) goto loop; else if (cp->c_flag & C_NOEXISTS) { /* * While we were blocked the cnode got deleted. */ vput(vp); goto loop; } if (VNODE_IS_RSRC(vp)) *rvpp = vp; else *vpp = vp; /* * Note that vget can block before aquiring the * cnode lock. So we need to check if the vnode * we wanted was created while we blocked. */ if (wantrsrc && *rvpp == NULL && cp->c_rsrc_vp) { error = vget(cp->c_rsrc_vp, 0, p); vput(*vpp); /* ref no longer needed */ *vpp = NULL; if (error) goto loop; *rvpp = cp->c_rsrc_vp; } else if (!wantrsrc && *vpp == NULL && cp->c_vp) { error = vget(cp->c_vp, 0, p); vput(*rvpp); /* ref no longer needed */ *rvpp = NULL; if (error) goto loop; *vpp = cp->c_vp; } return (cp); } simple_unlock(&hfs_chash_slock); return (NULL); } /* * Insert a cnode into the hash table. */ __private_extern__ void hfs_chashinsert(struct cnode *cp) { if (cp->c_fileid == 0) panic("hfs_chashinsert: trying to insert file id 0"); simple_lock(&hfs_chash_slock); LIST_INSERT_HEAD(CNODEHASH(cp->c_dev, cp->c_fileid), cp, c_hash); simple_unlock(&hfs_chash_slock); } /* * Remove a cnode from the hash table. */ __private_extern__ void hfs_chashremove(struct cnode *cp) { simple_lock(&hfs_chash_slock); LIST_REMOVE(cp, c_hash); cp->c_hash.le_next = NULL; cp->c_hash.le_prev = NULL; simple_unlock(&hfs_chash_slock); }