source: trunk/kernel/syscalls/sys_unlink.c @ 23

Last change on this file since 23 was 23, checked in by alain, 5 years ago

Introduce syscalls.

File size: 2.4 KB
Line 
1/*
2 * sys_unlink.c - file unlink
3 *
4 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
5 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
6 *
7 * This file is part of ALMOS-kernel.
8 *
9 * ALMOS-kernel is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2.0 of the License.
12 *
13 * ALMOS-kernel is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include <hal_types.h>
24#include <hal_uspace.h>
25#include <vfs.h>
26#include <process.h>
27#include <thread.h>
28#include <printk.h>
29
30//////////////////////////////////
31int sys_unlink ( char * pathname )
32{
33        error_t   error;
34    uint32_t  length;
35    char      kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
36
37        thread_t     * this     = CURRENT_THREAD;
38        process_t    * process  = this->process;
39
40    // get pathname length
41    length = hal_strlen_from_uspace( pathname );
42
43    if( length >= CONFIG_VFS_MAX_PATH_LENGTH )
44    {
45        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
46                this->errno = ENFILE;
47        return -1;
48    }
49 
50        // get pathname copy in kernel space
51    hal_copy_from_uspace( kbuf, pathname, length );
52
53    // get cluster and local pointer on reference process
54    xptr_t      ref_xp  = process->ref_xp;
55    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
56    cxy_t       ref_cxy = GET_CXY( ref_xp );
57
58    // get the cwd lock in read mode from reference process
59        remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
60
61    // get extended pointer on cwd inode
62    xptr_t cwd_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
63
64    // call relevant VFS function
65    error  = vfs_unlink( cwd_xp , kbuf );
66
67    // release the cwd lock in reference process
68        remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
69
70        if( error )
71        {
72        printk("\n[ERROR] in %s : cannot unlink file/dir %s\n",
73               __FUNCTION__ , pathname );
74                this->errno = ENFILE;
75            return -1;
76        }
77
78        return 0;
79
80} // end sys_unlink()
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