source: trunk/kernel/syscalls/sys_open.c @ 608

Last change on this file since 608 was 604, checked in by alain, 6 years ago

Improve the FAT32 file system to support cat, rm, cp commands.

File size: 3.7 KB
RevLine 
[1]1/*
[23]2 * sys_open.c - open a file.
[305]3 *
[23]4 * Author        Alain Greiner (2016,2017)
[1]5 *
[23]6 * Copyright (c) UPMC Sorbonne Universites
[1]7 *
[23]8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
[1]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 *
[23]14 * ALMOS-MKH is distributed in the hope that it will be useful, but
[1]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
[23]20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
[1]21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
[23]24#include <kernel_config.h>
[457]25#include <hal_kernel_types.h>
[23]26#include <hal_uspace.h>
[1]27#include <errno.h>
28#include <thread.h>
[23]29#include <printk.h>
[1]30#include <vfs.h>
31#include <process.h>
[23]32#include <remote_rwlock.h>
[1]33
[506]34#include <syscalls.h>
35
[1]36///////////////////////////////////
[566]37int sys_open ( char     * pathname,
38               uint32_t   flags,
39               uint32_t   mode )
[1]40{
[305]41    error_t        error;
42    xptr_t         file_xp;                          // extended pointer on vfs_file_t
43    uint32_t       file_id;                          // file descriptor index
[23]44    char           kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
[1]45
[305]46    thread_t     * this     = CURRENT_THREAD;
47    process_t    * process  = this->process;
[1]48
[594]49#if (DEBUG_SYS_OPEN || CONFIG_INSTRUMENTATION_SYSCALLS)
50uint64_t     tm_start = hal_get_cycles();
[459]51#endif
[594]52
[23]53    // check fd_array not full
[305]54    if( process_fd_array_full() )
55    {
[566]56
57#if DEBUG_SYSCALLS_ERROR
58printk("\n[ERROR] in %s : file descriptor array full for process %x\n",
59__FUNCTION__ , process->pid );
60#endif
[305]61        this->errno = ENFILE;
[23]62        return -1;
[305]63    }
[1]64
[407]65    // check pathname length
66    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
[23]67    {
[566]68
69#if DEBUG_SYSCALLS_ERROR
70printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
71#endif
[305]72        this->errno = ENFILE;
[23]73        return -1;
74    }
[1]75
[407]76    // copy pathname in kernel space
77    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
78
[459]79#if DEBUG_SYS_OPEN
80if( DEBUG_SYS_OPEN < tm_start )
[594]81printk("\n[%s] thread[%x,%x] enter for <%s> / flags %x / cycle %d\n",
82__FUNCTION__, process->pid, this->trdid, kbuf, flags, (uint32_t)tm_start );
[459]83#endif
84 
[23]85    // get cluster and local pointer on reference process
86    xptr_t      ref_xp  = process->ref_xp;
87    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
88    cxy_t       ref_cxy = GET_CXY( ref_xp );
89
90    // get the cwd lock in read mode from reference process
[566]91    remote_rwlock_rd_acquire( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[23]92
93    // call the relevant VFS function
[407]94    error = vfs_open( process,
[23]95                      kbuf,
96                      flags,
97                      mode,
98                      &file_xp,
99                      &file_id );
100
101    // release the cwd lock
[566]102    remote_rwlock_rd_release( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[23]103
[305]104    if( error )
105    {
[459]106        printk("\n[ERROR] in %s : cannot create file descriptor for %s\n",
107        __FUNCTION__ , kbuf );
[305]108        this->errno = ENFILE;
109        return -1;
110    }
[1]111
[599]112    hal_fence();
[594]113
114#if (DEBUG_SYS_OPEN || CONFIG_INSTRUMENTATION_SYSCALLS)
115uint64_t     tm_end = hal_get_cycles();
116#endif
117
[459]118#if DEBUG_SYS_OPEN
[604]119if( DEBUG_SYS_OPEN < tm_end )
[594]120printk("\n[%s] thread[%x,%x] exit for <%s> / cycle %d\n",
121__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_end );
[459]122#endif
123 
[594]124#if CONFIG_INSTRUMENTATION_SYSCALLS
125hal_atomic_add( &syscalls_cumul_cost[SYS_OPEN] , tm_end - tm_start );
126hal_atomic_add( &syscalls_occurences[SYS_OPEN] , 1 );
127#endif
128
[305]129    return file_id;
[1]130}
Note: See TracBrowser for help on using the repository browser.