更新日期: 2022/06/01 来源: https://gitee.com/weharmony/kernel_liteos_a_note
vfs_chattr.c
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1/*
2 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
3 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this list of
9 * conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
12 * of conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
16 * to endorse or promote products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/****************************************************************************
33 * Included Files
34 ****************************************************************************/
35
36#include "capability_api.h"
37#include "errno.h"
38#include "fs/fs_operation.h"
39#include "fs/file.h"
40#include "string.h"
41#include "stdlib.h"
42#include "sys/stat.h"
43#include "vnode.h"
44#include "fs/mount.h"
45#include <fcntl.h>
46
47/****************************************************************************
48 * Static Functions
49 ****************************************************************************/
50/****************************************************************************
51 * Name: chattr
52 *
53 * Returned Value:
54 * Zero on success; -1 on failure with errno set:
55 *
56 ****************************************************************************/
57
58int chattr(const char *pathname, struct IATTR *attr)
59{
60 struct Vnode *vnode = NULL;
61 int ret;
62
63 if (pathname == NULL || attr == NULL) {
64 set_errno(EINVAL);
65 return VFS_ERROR;
66 }
67
68 VnodeHold();
69 ret = VnodeLookup(pathname, &vnode, 0);
70 if (ret != LOS_OK) {
71 goto errout_with_lock;
72 }
73
74 if ((vnode->originMount) && (vnode->originMount->mountFlags & MS_RDONLY)) {
75 ret = -EROFS;
76 goto errout_with_lock;
77 }
78
79 /* The way we handle the stat depends on the type of vnode that we
80 * are dealing with.
81 */
82
83 if (vnode->vop != NULL && vnode->vop->Chattr != NULL) {
84 ret = vnode->vop->Chattr(vnode, attr);
85 } else {
86 ret = -ENOSYS;
87 }
88 VnodeDrop();
89
90 if (ret < 0) {
91 goto errout;
92 }
93
94 return OK;
95
96 /* Failure conditions always set the errno appropriately */
97
98errout_with_lock:
99 VnodeDrop();
100errout:
101 set_errno(-ret);
102 return VFS_ERROR;
103}
此结构用于记录 vnode 的属性
Definition: vnode.h:81
unsigned long mountFlags
Definition: mount.h:80
vnode并不包含文件名,因为 vnode和文件名是 1:N 的关系
Definition: vnode.h:164
struct VnodeOps * vop
Definition: vnode.h:174
struct Mount * originMount
Definition: vnode.h:180
int(* Chattr)(struct Vnode *vnode, struct IATTR *attr)
改变节点属性(change attr)
Definition: vnode.h:214
int VnodeDrop(void)
归还锁
Definition: vnode.c:292
int VnodeHold(void)
拿锁,封装互斥量
Definition: vnode.c:283
int VnodeLookup(const char *path, struct Vnode **vnode, uint32_t flags)
通过路径查询vnode节点
Definition: vnode.c:491
int chattr(const char *pathname, struct IATTR *attr)
Definition: vfs_chattr.c:58