source: trunk/kernel/syscalls/sys_chdir.c @ 506

Last change on this file since 506 was 506, checked in by viala@…, 3 years ago

[syscalls] add interface in implementation.

Add const where possible, fix protoypes to follow interface.

File size: 2.3 KB
Line 
1/*
2 * sys_chdir: change process current working directory
3 *
4 * Author    Alain Greiner (2016,2017)
5 *
6 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <hal_kernel_types.h>
25#include <hal_uspace.h>
26#include <chdev.h>
27#include <rwlock.h>
28#include <vfs.h>
29#include <errno.h>
30#include <thread.h>
31#include <printk.h>
32#include <process.h>
33
34#include <syscalls.h>
35
36/////////////////////////////////
37int sys_chdir ( const char * pathname )
38{
39    error_t   error;
40    char      kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
41
42    thread_t  * this    = CURRENT_THREAD;
43    process_t * process = this->process;
44
45    // check pathname length
46    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
47    {
48        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
49        this->errno = ENFILE;
50        return -1;
51    }
52
53    // copy pathname in kernel space
54    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
55
56    // get cluster and local pointer on reference process
57    xptr_t      ref_xp  = process->ref_xp;
58    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
59    cxy_t       ref_cxy = GET_CXY( ref_xp );
60
61    // get extended pointer on cwd lock in reference process
62    xptr_t lock_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
63
64    // get cwd lock in read mode
65    remote_rwlock_rd_lock( lock_xp );
66
67    // call relevant VFS function
68    error = vfs_chdir( process->vfs_cwd_xp , kbuf );
69
70    // release cwd lock
71    remote_rwlock_rd_unlock( lock_xp );
72
73    if( error )
74    {
75        printk("\n[ERROR] in %s : cannot change current directory\n", __FUNCTION__ );
76        this->errno = error;
77        return -1;
78    }
79
80    return 0;
81}
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