source: trunk/kernel/syscalls/sys_open.c@ 305

Last change on this file since 305 was 305, checked in by max@…, 9 years ago

Style, and use hal_strcpy_from_uspace.

File size: 3.2 KB
Line 
1/*
2 * sys_open.c - open a file.
3 *
4 * Author Alain Greiner (2016,2017)
5 *
6 * Copyright (c) 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 <kernel_config.h>
25#include <hal_types.h>
26#include <hal_uspace.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <vfs.h>
31#include <process.h>
32#include <remote_spinlock.h>
33#include <remote_rwlock.h>
34
35///////////////////////////////////
36int sys_open ( char * pathname,
37 uint32_t flags,
38 uint32_t mode )
39{
40 error_t error;
41 xptr_t file_xp; // extended pointer on vfs_file_t
42 uint32_t file_id; // file descriptor index
43 char kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
44
45 thread_t * this = CURRENT_THREAD;
46 process_t * process = this->process;
47
48 // check fd_array not full
49 if( process_fd_array_full() )
50 {
51 printk("\n[ERROR] in %s : file descriptor array full for process %x\n",
52 __FUNCTION__ , process->pid );
53 this->errno = ENFILE;
54 return -1;
55 }
56
57 // get pathname copy in kernel space
58 error = hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
59
60 if( error )
61 {
62 printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
63 this->errno = ENFILE;
64 return -1;
65 }
66
67 // get cluster and local pointer on reference process
68 xptr_t ref_xp = process->ref_xp;
69 process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
70 cxy_t ref_cxy = GET_CXY( ref_xp );
71
72 // get extended pointer on cwd inode
73 xptr_t cwd_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
74
75 // get the cwd lock in read mode from reference process
76 remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
77
78 // call the relevant VFS function
79 error = vfs_open( cwd_xp,
80 kbuf,
81 flags,
82 mode,
83 &file_xp,
84 &file_id );
85
86 // release the cwd lock
87 remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
88
89 if( error )
90 {
91 printk("\n[ERROR] in %s : cannot create file descriptor\n", __FUNCTION__ );
92 this->errno = ENFILE;
93 return -1;
94 }
95
96 // update local fd_array
97 remote_spinlock_lock( XPTR( local_cxy , &process->fd_array.lock ) );
98 process->fd_array.array[file_id] = file_xp;
99 remote_spinlock_unlock( XPTR( local_cxy , &process->fd_array.lock ) );
100
101 return file_id;
102}
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