157 lines
4.2 KiB
C
157 lines
4.2 KiB
C
/*-
|
|
* Copyright (c) 2005 Poul-Henning Kamp
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
*
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/vnode.h>
|
|
|
|
static MALLOC_DEFINE(M_VFS_HASH, "VFS hash", "VFS hash table");
|
|
|
|
static LIST_HEAD(vfs_hash_head, vnode) *vfs_hash_tbl;
|
|
static LIST_HEAD(,vnode) vfs_hash_side;
|
|
static u_long vfs_hash_mask;
|
|
static struct mtx vfs_hash_mtx;
|
|
|
|
static void
|
|
vfs_hashinit(void *dummy __unused)
|
|
{
|
|
|
|
vfs_hash_tbl = hashinit(desiredvnodes, M_VFS_HASH, &vfs_hash_mask);
|
|
mtx_init(&vfs_hash_mtx, "vfs hash", NULL, MTX_DEF);
|
|
LIST_INIT(&vfs_hash_side);
|
|
}
|
|
|
|
/* Must be SI_ORDER_SECOND so desiredvnodes is available */
|
|
SYSINIT(vfs_hash, SI_SUB_VFS, SI_ORDER_SECOND, vfs_hashinit, NULL)
|
|
|
|
static struct vfs_hash_head *
|
|
vfs_hash_index(struct mount *mp, u_int hash)
|
|
{
|
|
|
|
return(&vfs_hash_tbl[(hash + mp->mnt_hashseed) & vfs_hash_mask]);
|
|
}
|
|
|
|
int
|
|
vfs_hash_get(struct mount *mp, u_int hash, int flags, struct thread *td, struct vnode **vpp, vfs_hash_cmp_t *fn, void *arg)
|
|
{
|
|
struct vnode *vp;
|
|
int error;
|
|
|
|
while (1) {
|
|
mtx_lock(&vfs_hash_mtx);
|
|
LIST_FOREACH(vp, vfs_hash_index(mp, hash), v_hashlist) {
|
|
if (vp->v_hash != hash)
|
|
continue;
|
|
if (vp->v_mount != mp)
|
|
continue;
|
|
if (fn != NULL && fn(vp, arg))
|
|
continue;
|
|
VI_LOCK(vp);
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
error = vget(vp, flags | LK_INTERLOCK, td);
|
|
if (error == ENOENT)
|
|
break;
|
|
if (error)
|
|
return (error);
|
|
*vpp = vp;
|
|
return (0);
|
|
}
|
|
if (vp == NULL) {
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
*vpp = NULL;
|
|
return (0);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
vfs_hash_remove(struct vnode *vp)
|
|
{
|
|
|
|
mtx_lock(&vfs_hash_mtx);
|
|
LIST_REMOVE(vp, v_hashlist);
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
}
|
|
|
|
int
|
|
vfs_hash_insert(struct vnode *vp, u_int hash, int flags, struct thread *td, struct vnode **vpp, vfs_hash_cmp_t *fn, void *arg)
|
|
{
|
|
struct vnode *vp2;
|
|
int error;
|
|
|
|
lockmgr(vp->v_vnlock, flags & LK_TYPE_MASK, NULL, td);
|
|
*vpp = NULL;
|
|
while (1) {
|
|
mtx_lock(&vfs_hash_mtx);
|
|
LIST_FOREACH(vp2,
|
|
vfs_hash_index(vp->v_mount, hash), v_hashlist) {
|
|
if (vp2->v_hash != hash)
|
|
continue;
|
|
if (vp2->v_mount != vp->v_mount)
|
|
continue;
|
|
if (fn != NULL && fn(vp2, arg))
|
|
continue;
|
|
VI_LOCK(vp2);
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
error = vget(vp2, flags | LK_INTERLOCK, td);
|
|
if (error == ENOENT)
|
|
break;
|
|
mtx_lock(&vfs_hash_mtx);
|
|
LIST_INSERT_HEAD(&vfs_hash_side, vp, v_hashlist);
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
vput(vp);
|
|
if (!error)
|
|
*vpp = vp2;
|
|
return (error);
|
|
}
|
|
if (vp2 == NULL)
|
|
break;
|
|
|
|
}
|
|
vp->v_hash = hash;
|
|
LIST_INSERT_HEAD(vfs_hash_index(vp->v_mount, hash), vp, v_hashlist);
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
vfs_hash_rehash(struct vnode *vp, u_int hash)
|
|
{
|
|
|
|
mtx_lock(&vfs_hash_mtx);
|
|
LIST_REMOVE(vp, v_hashlist);
|
|
LIST_INSERT_HEAD(&vfs_hash_tbl[hash & vfs_hash_mask], vp, v_hashlist);
|
|
vp->v_hash = hash;
|
|
mtx_unlock(&vfs_hash_mtx);
|
|
}
|