source: trunk/kernel/syscalls/sys_open.c @ 610

Last change on this file since 610 was 610, checked in by alain, 3 years ago

Fix several bugs in VFS to support the following
ksh commandis : cp, mv, rm, mkdir, cd, pwd

File size: 4.0 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_kernel_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_rwlock.h>
33
34#include <syscalls.h>
35
36///////////////////////////////////
37int sys_open ( char     * pathname,
38               uint32_t   flags,
39               uint32_t   mode )
40{
41    error_t        error;
42    xptr_t         file_xp;                 // extended pointer on vfs_file_t
43    uint32_t       file_id;                 // file descriptor index
44    xptr_t         root_inode_xp;           // extended pointer on path root inode
45
46    char           kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
47
48    thread_t     * this     = CURRENT_THREAD;
49    process_t    * process  = this->process;
50
51#if (DEBUG_SYS_OPEN || CONFIG_INSTRUMENTATION_SYSCALLS)
52uint64_t     tm_start = hal_get_cycles();
53#endif
54
55    // check fd_array not full
56    if( process_fd_array_full() )
57    {
58
59#if DEBUG_SYSCALLS_ERROR
60printk("\n[ERROR] in %s : file descriptor array full for process %x\n",
61__FUNCTION__ , process->pid );
62#endif
63        this->errno = ENFILE;
64        return -1;
65    }
66
67    // check pathname length
68    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
69    {
70
71#if DEBUG_SYSCALLS_ERROR
72printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
73#endif
74        this->errno = ENFILE;
75        return -1;
76    }
77
78    // copy pathname in kernel space
79    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
80
81#if DEBUG_SYS_OPEN
82if( DEBUG_SYS_OPEN < tm_start )
83printk("\n[%s] thread[%x,%x] enter for <%s> / flags %x / cycle %d\n",
84__FUNCTION__, process->pid, this->trdid, kbuf, flags, (uint32_t)tm_start );
85#endif
86 
87    // get cluster and local pointer on reference process
88    xptr_t      ref_xp  = process->ref_xp;
89    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
90    cxy_t       ref_cxy = GET_CXY( ref_xp );
91
92    // compute root inode for path
93    if( kbuf[0] == '/' )                        // absolute path
94    {
95        // use extended pointer on VFS root inode
96        root_inode_xp = process->vfs_root_xp;
97    }
98    else                                        // relative path
99    {
100        // use extended pointer on CWD inode
101        root_inode_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->cwd_xp ) );
102    }
103
104    // call the relevant VFS function
105    error = vfs_open( root_inode_xp,
106                      kbuf,
107                      ref_xp,
108                      flags,
109                      mode,
110                      &file_xp,
111                      &file_id );
112
113    if( error )
114    {
115        printk("\n[ERROR] in %s : cannot create file descriptor for %s\n",
116        __FUNCTION__ , kbuf );
117        this->errno = ENFILE;
118        return -1;
119    }
120
121    hal_fence();
122
123#if (DEBUG_SYS_OPEN || CONFIG_INSTRUMENTATION_SYSCALLS)
124uint64_t     tm_end = hal_get_cycles();
125#endif
126
127#if DEBUG_SYS_OPEN
128if( DEBUG_SYS_OPEN < tm_end )
129printk("\n[%s] thread[%x,%x] exit for <%s> / cycle %d\n",
130__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_end );
131#endif
132 
133#if CONFIG_INSTRUMENTATION_SYSCALLS
134hal_atomic_add( &syscalls_cumul_cost[SYS_OPEN] , tm_end - tm_start );
135hal_atomic_add( &syscalls_occurences[SYS_OPEN] , 1 );
136#endif
137
138    return file_id;
139}
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