b49b7fe799
license, per letter dated July 22, 1999 and email from Peter Wemm, Alan Cox and Robert Watson. Approved by: core, peter, alc, rwatson
170 lines
4.5 KiB
C
170 lines
4.5 KiB
C
/*
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* Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/vnode.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/mutex.h>
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#include <gnu/ext2fs/inode.h>
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#include <gnu/ext2fs/ext2_extern.h>
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static MALLOC_DEFINE(M_EXT2IHASH, "EXT2 ihash", "EXT2 Inode hash tables");
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/*
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* Structures associated with inode cacheing.
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*/
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static LIST_HEAD(ihashhead, inode) *ihashtbl;
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static u_long ihash; /* size of hash table - 1 */
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#define INOHASH(device, inum) (&ihashtbl[(minor(device) + (inum)) & ihash])
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static struct mtx ext2_ihash_mtx;
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/*
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* Initialize inode hash table.
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*/
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void
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ext2_ihashinit()
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{
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KASSERT(ihashtbl == NULL, ("ext2_ihashinit called twice"));
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ihashtbl = hashinit(desiredvnodes, M_EXT2IHASH, &ihash);
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mtx_init(&ext2_ihash_mtx, "ext2 ihash", NULL, MTX_DEF);
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}
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/*
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* Destroy the inode hash table.
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*/
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void
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ext2_ihashuninit()
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{
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hashdestroy(ihashtbl, M_EXT2IHASH, ihash);
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mtx_destroy(&ext2_ihash_mtx);
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}
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/*
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* Use the device/inum pair to find the incore inode, and return a pointer
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* to it. If it is in core, return it, even if it is locked.
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*/
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struct vnode *
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ext2_ihashlookup(dev, inum)
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dev_t dev;
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ino_t inum;
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{
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struct inode *ip;
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mtx_lock(&ext2_ihash_mtx);
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LIST_FOREACH(ip, INOHASH(dev, inum), i_hash)
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if (inum == ip->i_number && dev == ip->i_dev)
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break;
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mtx_unlock(&ext2_ihash_mtx);
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if (ip)
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return (ITOV(ip));
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return (NULLVP);
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}
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/*
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* Use the device/inum pair to find the incore inode, and return a pointer
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* to it. If it is in core, but locked, wait for it.
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*/
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int
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ext2_ihashget(dev, inum, flags, vpp)
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dev_t dev;
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ino_t inum;
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int flags;
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struct vnode **vpp;
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{
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struct thread *td = curthread; /* XXX */
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struct inode *ip;
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struct vnode *vp;
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int error;
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*vpp = NULL;
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loop:
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mtx_lock(&ext2_ihash_mtx);
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LIST_FOREACH(ip, INOHASH(dev, inum), i_hash) {
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if (inum == ip->i_number && dev == ip->i_dev) {
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vp = ITOV(ip);
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mtx_lock(&vp->v_interlock);
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mtx_unlock(&ext2_ihash_mtx);
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error = vget(vp, flags | LK_INTERLOCK, td);
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if (error == ENOENT)
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goto loop;
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if (error)
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return (error);
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*vpp = vp;
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return (0);
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}
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}
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mtx_unlock(&ext2_ihash_mtx);
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return (0);
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}
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/*
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* Insert the inode into the hash table, and return it locked.
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*/
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void
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ext2_ihashins(ip)
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struct inode *ip;
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{
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struct thread *td = curthread; /* XXX */
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struct ihashhead *ipp;
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/* lock the inode, then put it on the appropriate hash list */
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vn_lock(ITOV(ip), LK_EXCLUSIVE | LK_RETRY, td);
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mtx_lock(&ext2_ihash_mtx);
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ipp = INOHASH(ip->i_dev, ip->i_number);
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LIST_INSERT_HEAD(ipp, ip, i_hash);
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ip->i_flag |= IN_HASHED;
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mtx_unlock(&ext2_ihash_mtx);
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}
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/*
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* Remove the inode from the hash table.
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*/
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void
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ext2_ihashrem(ip)
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struct inode *ip;
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{
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mtx_lock(&ext2_ihash_mtx);
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if (ip->i_flag & IN_HASHED) {
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ip->i_flag &= ~IN_HASHED;
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LIST_REMOVE(ip, i_hash);
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}
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mtx_unlock(&ext2_ihash_mtx);
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}
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