source: trunk/kernel/syscalls/sys_stat.c @ 435

Last change on this file since 435 was 407, checked in by alain, 6 years ago

First implementation of fork/exec.

File size: 3.4 KB
Line 
1/*
2 * sys_stat.c - Return statistics on a file or directory.
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 <hal_types.h>
25#include <hal_uspace.h>
26#include <hal_special.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <vfs.h>
31#include <vmm.h>
32#include <process.h>
33
34/////////////////////////////////////
35int sys_stat( char        * pathname,
36              struct stat * u_stat )
37{
38    error_t       error;
39    paddr_t       paddr;
40    struct stat   k_stat;       // kernel space
41    xptr_t        file_xp;
42    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
43       
44        thread_t  * this    = CURRENT_THREAD;
45        process_t * process = this->process;
46
47    // check stat structure in user space
48    error = vmm_v2p_translate( false , u_stat , &paddr );
49
50        if( error )
51        {
52        printk("\n[ERROR] in %s : stat structure unmapped  for thread %x in process %x\n",
53               __FUNCTION__ , this->trdid , process->pid );
54                this->errno = EINVAL;
55                return -1;
56        }       
57
58    // check pathname length
59    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
60    {
61        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
62        this->errno = ENFILE;
63        return -1;
64    }
65
66    // copy pathname in kernel space
67    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
68
69    // get cluster and local pointer on reference process
70    xptr_t      ref_xp  = process->ref_xp;
71    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
72    cxy_t       ref_cxy = GET_CXY( ref_xp );
73
74    // get extended pointer on cwd inode
75    xptr_t cwd_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
76
77    // get the cwd lock in read mode from reference process
78    remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
79
80    // get extended pointer on remote file descriptor
81    error = vfs_lookup( cwd_xp,
82                        pathname,
83                        0,
84                        &file_xp );
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 found file <%s> for thread %x in process %x\n",
92               __FUNCTION__ , pathname , this->trdid , process->pid );
93        this->errno = error;
94        return -1;
95    }
96
97    // call VFS function to get stat info
98    error = vfs_stat( file_xp,
99                      &k_stat );
100    if( error )
101        {
102        printk("\n[ERROR] in %s : cannot get stats for file %s\n",
103               __FUNCTION__ , pathname );
104                this->errno = error;
105                return -1;
106        }
107   
108    // copy k_stat to u_stat
109    hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
110
111    hal_fence();
112
113        return 0;
114
115}  // end sys_stat()
116
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