source: trunk/kernel/syscalls/sys_stat.c @ 566

Last change on this file since 566 was 566, checked in by alain, 5 years ago

Complete restructuration of kernel locks.

File size: 3.5 KB
RevLine 
[1]1/*
[23]2 * sys_stat.c - Return statistics on a file or directory.
[1]3 *
[440]4 * Author    Alain Greiner  (2016,2017,2018)
[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
[457]24#include <hal_kernel_types.h>
[23]25#include <hal_uspace.h>
26#include <hal_special.h>
[1]27#include <errno.h>
28#include <thread.h>
[23]29#include <printk.h>
[1]30#include <vfs.h>
[23]31#include <vmm.h>
32#include <process.h>
[1]33
[506]34#include <syscalls.h>
35
[407]36/////////////////////////////////////
[566]37int sys_stat( char        * pathname,
[407]38              struct stat * u_stat )
[1]39{
[407]40    error_t       error;
[440]41    vseg_t      * vseg;         // for user space checking
[407]42    struct stat   k_stat;       // kernel space
43    xptr_t        file_xp;
44    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
[23]45       
46        thread_t  * this    = CURRENT_THREAD;
47        process_t * process = this->process;
[1]48
[23]49    // check stat structure in user space
[440]50    error = vmm_get_vseg( process , (intptr_t)u_stat , &vseg );
[1]51
[23]52        if( error )
[1]53        {
[440]54
[509]55#if DEBUG_SYSCALLS_ERROR
[440]56printk("\n[ERROR] in %s : stat structure unmapped %x / thread %x / process %x\n",
57__FUNCTION__ , (intptr_t)u_stat , this->trdid , process->pid );
58vmm_display( process , false );
59#endif
[23]60                this->errno = EINVAL;
[1]61                return -1;
[23]62        }       
[1]63
[407]64    // check pathname length
65    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
66    {
67        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
68        this->errno = ENFILE;
69        return -1;
70    }
71
72    // copy pathname in kernel space
73    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
74
75    // get cluster and local pointer on reference process
76    xptr_t      ref_xp  = process->ref_xp;
77    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
78    cxy_t       ref_cxy = GET_CXY( ref_xp );
79
80    // get extended pointer on cwd inode
[566]81    xptr_t cwd_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
[407]82
83    // get the cwd lock in read mode from reference process
[566]84    remote_rwlock_rd_acquire( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[407]85
[23]86    // get extended pointer on remote file descriptor
[407]87    error = vfs_lookup( cwd_xp,
88                        pathname,
89                        0,
90                        &file_xp );
[23]91
[407]92    // release the cwd lock
[566]93    remote_rwlock_rd_release( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[407]94
95    if( error )
[23]96    {
[407]97        printk("\n[ERROR] in %s : cannot found file <%s> for thread %x in process %x\n",
98               __FUNCTION__ , pathname , this->trdid , process->pid );
99        this->errno = error;
[23]100        return -1;
101    }
102
[407]103    // call VFS function to get stat info
[23]104    error = vfs_stat( file_xp,
105                      &k_stat );
106    if( error )
[1]107        {
[407]108        printk("\n[ERROR] in %s : cannot get stats for file %s\n",
109               __FUNCTION__ , pathname );
[23]110                this->errno = error;
[1]111                return -1;
112        }
[23]113   
[407]114    // copy k_stat to u_stat
115    hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
[1]116
[124]117    hal_fence();
[23]118
[1]119        return 0;
[23]120
121}  // end sys_stat()
122
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