source: trunk/kernel/syscalls/sys_opendir.c @ 611

Last change on this file since 611 was 611, checked in by alain, 3 years ago

Introduce sigificant modifs in VFS to support the <ls> command,
and the . and .. directories entries.

File size: 5.9 KB
Line 
1/*
2 * sys_opendir.c - Open a VFS directory.
3 *
4 * Author        Alain Greiner (2016,2017,2018)
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 <thread.h>
28#include <process.h>
29#include <remote_dir.h>
30#include <printk.h>
31#include <errno.h>
32#include <vseg.h>
33#include <vfs.h>
34#include <syscalls.h>
35#include <shared_syscalls.h>
36
37///////////////////////////////////
38int sys_opendir ( char *  pathname,
39                  DIR  ** dirp )
40{
41    error_t        error;
42    xptr_t         root_inode_xp;          // extended pointer on path root inode
43    xptr_t         inode_xp;               // extended pointer on directory inode
44    vfs_inode_t  * inode_ptr;              // local pointer on directory inode
45    cxy_t          inode_cxy;              // directory inode cluster
46    uint32_t       inode_type;             // to check directory inode type
47    xptr_t         dir_xp;                 // extended pointer on remote_dir_t
48    remote_dir_t * dir_ptr;                // local pointer on remote_dir_t
49    cxy_t          dir_cxy;                // remote_dir_t cluster identifier
50    vseg_t       * vseg;                   // for user space checking
51    intptr_t       ident;                  // dirent array pointer in user space                 
52    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
53       
54        thread_t     * this    = CURRENT_THREAD;  // client thread
55        process_t    * process = this->process;   // client process
56
57#if (DEBUG_SYS_OPENDIR || CONFIG_INSTRUMENTATION_SYSCALLS)
58uint64_t     tm_start = hal_get_cycles();
59#endif
60
61    // check DIR buffer in user space
62    error = vmm_get_vseg( process , (intptr_t)dirp, &vseg );
63
64        if( error )
65        {
66
67#if DEBUG_SYSCALLS_ERROR
68printk("\n[ERROR] in %s / thread[%x,%x] : DIR buffer %x unmapped\n",
69__FUNCTION__ , process->pid , this->trdid, dirp );
70vmm_display( process , false );
71#endif
72                this->errno = EINVAL;
73                return -1;
74        }       
75
76    // check pathname length
77    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
78    {
79
80#if DEBUG_SYSCALLS_ERROR
81printk("\n[ERROR] in %s / thread[%x,%x] : pathname too long\n",
82 __FUNCTION__ , process->pid , this->trdid );
83#endif
84        this->errno = ENFILE;
85        return -1;
86    }
87
88    // copy pathname in kernel space
89    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
90
91#if DEBUG_SYS_OPENDIR
92if( DEBUG_SYS_OPENDIR < tm_start )
93printk("\n[%s] thread[%x,%x] enter for directory <%s> / cycle %d\n",
94__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_start );
95#endif
96
97    // compute root inode for pathname
98    if( kbuf[0] == '/' )                        // absolute path
99    {
100        // use extended pointer on VFS root inode
101        root_inode_xp = process->vfs_root_xp;
102    }
103    else                                        // relative path
104    {
105        // get cluster and local pointer on reference process
106        xptr_t      ref_xp  = process->ref_xp;
107        process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
108        cxy_t       ref_cxy = GET_CXY( ref_xp );
109
110        // use extended pointer on CWD inode
111        root_inode_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->cwd_xp ) );
112    }
113
114    // get extended pointer on directory inode
115    error = vfs_lookup( root_inode_xp,
116                        kbuf,
117                        0,
118                        &inode_xp,
119                        NULL );
120    if( error )
121        {
122
123#if DEBUG_SYSCALLS_ERROR
124printk("\n[ERROR] in %s / thread[%x,%x] : cannot found directory <%s>\n",
125__FUNCTION__ , process->pid , this->trdid , kbuf );
126#endif
127                this->errno = ENFILE;
128                return -1;
129        }
130   
131    // check inode type
132    inode_ptr  = GET_PTR( inode_xp );
133    inode_cxy  = GET_CXY( inode_xp );
134    inode_type = hal_remote_l32( XPTR( inode_cxy , &inode_ptr->type ) );
135
136    if( inode_type != INODE_TYPE_DIR )
137        {
138
139#if DEBUG_SYSCALLS_ERROR
140printk("\n[ERROR] in %s / thread[%x,%x] : cannot found directory <%s>\n",
141__FUNCTION__ , process->pid , this->trdid , kbuf );
142#endif
143                this->errno = ENFILE;
144                return -1;
145        }
146   
147    // allocate, initialize, and register a new remote_dir_t structure
148    // in the calling process reference cluster
149    dir_xp  = remote_dir_create( inode_xp );
150    dir_ptr = GET_PTR( dir_xp );
151    dir_cxy = GET_CXY( dir_xp );
152
153    if( dir_xp == XPTR_NULL )
154        {
155
156#if DEBUG_SYSCALLS_ERROR
157printk("\n[ERROR] in %s / thread[%x,%x] : cannot create remote_dir for <%s>\n",
158__FUNCTION__ , process->pid , this->trdid , kbuf );
159#endif
160                this->errno = ENFILE;
161                return -1;
162        }
163   
164    // get ident from remote_dir structure
165    ident = (intptr_t)hal_remote_lpt( XPTR( dir_cxy , &dir_ptr->ident ) );
166
167    // set ident value in user buffer
168    hal_copy_to_uspace( dirp , &ident , sizeof(intptr_t) );
169
170    hal_fence();
171
172#if (DEBUG_SYS_OPENDIR || CONFIG_INSTRUMENTATION_SYSCALLS)
173uint64_t     tm_end = hal_get_cycles();
174#endif
175
176#if DEBUG_SYS_OPENDIR
177if( DEBUG_SYS_OPENDIR < tm_end )
178printk("\n[%s] thread[%x,%x] exit for directory <%s> / cycle %d\n",
179__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_end );
180#endif
181 
182#if CONFIG_INSTRUMENTATION_SYSCALLS
183hal_atomic_add( &syscalls_cumul_cost[SYS_OPENDIR] , tm_end - tm_start );
184hal_atomic_add( &syscalls_occurences[SYS_OPENDIR] , 1 );
185#endif
186
187        return 0;
188
189}  // end sys_opendir()
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