kernel_liteos_a/fs/vfs/vnode_hash.c

137 lines
4.3 KiB
C

/*
* Copyright (c) 2021-2021 Huawei Device Co., Ltd. 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. Neither the name of the copyright holder 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "los_mux.h"
#include "fs/vnode.h"
#define VNODE_HASH_BUCKETS 128
LIST_HEAD g_vnodeHashEntrys[VNODE_HASH_BUCKETS];
uint32_t g_vnodeHashMask = VNODE_HASH_BUCKETS - 1;
uint32_t g_vnodeHashSize = VNODE_HASH_BUCKETS;
static LosMux g_vnodeHashMux;
int VnodeHashInit(void)
{
int ret;
for (int i = 0; i < g_vnodeHashSize; i++) {
LOS_ListInit(&g_vnodeHashEntrys[i]);
}
ret = LOS_MuxInit(&g_vnodeHashMux, NULL);
if (ret != LOS_OK) {
PRINT_ERR("Create mutex for vnode hash list fail, status: %d", ret);
return ret;
}
return LOS_OK;
}
void VnodeHashDump(void)
{
PRINTK("-------->VnodeHashDump in\n");
(void)LOS_MuxLock(&g_vnodeHashMux, LOS_WAIT_FOREVER);
for (int i = 0; i < g_vnodeHashSize; i++) {
LIST_HEAD *nhead = &g_vnodeHashEntrys[i];
struct Vnode *node = NULL;
LOS_DL_LIST_FOR_EACH_ENTRY(node, nhead, struct Vnode, hashEntry) {
PRINTK(" vnode dump: col %d item %p\n", i, node);
}
}
(void)LOS_MuxUnlock(&g_vnodeHashMux);
PRINTK("-------->VnodeHashDump out\n");
}
uint32_t VfsHashIndex(struct Vnode *vnode)
{
if (vnode == NULL) {
return -EINVAL;
}
return (vnode->hash + vnode->originMount->hashseed);
}
static LOS_DL_LIST *VfsHashBucket(const struct Mount *mp, uint32_t hash)
{
return (&g_vnodeHashEntrys[(hash + mp->hashseed) & g_vnodeHashMask]);
}
int VfsHashGet(const struct Mount *mount, uint32_t hash, struct Vnode **vnode, VfsHashCmp *fn, void *arg)
{
struct Vnode *curVnode = NULL;
if (mount == NULL || vnode == NULL) {
return -EINVAL;
}
(void)LOS_MuxLock(&g_vnodeHashMux, LOS_WAIT_FOREVER);
LOS_DL_LIST *list = VfsHashBucket(mount, hash);
LOS_DL_LIST_FOR_EACH_ENTRY(curVnode, list, struct Vnode, hashEntry) {
if (curVnode->hash != hash) {
continue;
}
if (curVnode->originMount != mount) {
continue;
}
if (fn != NULL && fn(curVnode, arg)) {
continue;
}
(void)LOS_MuxUnlock(&g_vnodeHashMux);
*vnode = curVnode;
return LOS_OK;
}
(void)LOS_MuxUnlock(&g_vnodeHashMux);
*vnode = NULL;
return LOS_NOK;
}
void VfsHashRemove(struct Vnode *vnode)
{
if (vnode == NULL) {
return;
}
(void)LOS_MuxLock(&g_vnodeHashMux, LOS_WAIT_FOREVER);
LOS_ListDelete(&vnode->hashEntry);
(void)LOS_MuxUnlock(&g_vnodeHashMux);
}
int VfsHashInsert(struct Vnode *vnode, uint32_t hash)
{
if (vnode == NULL) {
return -EINVAL;
}
(void)LOS_MuxLock(&g_vnodeHashMux, LOS_WAIT_FOREVER);
vnode->hash = hash;
LOS_ListHeadInsert(VfsHashBucket(vnode->originMount, hash), &vnode->hashEntry);
(void)LOS_MuxUnlock(&g_vnodeHashMux);
return LOS_OK;
}