source: trunk/kernel/syscalls/sys_opendir.c @ 612

Last change on this file since 612 was 612, checked in by alain, 3 years ago

Fix several bugs in vfs.c, fatfs.c, and devfs.c to support
the <.> and <..> directory entries.

File size: 5.9 KB
Line 
1/*
2 * sys_opendir.c - Open an user accessible 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 <user_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    user_dir_t   * dir_ptr;                // local pointer on user_dir_t
48    vseg_t       * vseg;                   // for user space checking
49    intptr_t       ident;                  // dirent array pointer in user space                 
50    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
51       
52        thread_t     * this    = CURRENT_THREAD;  // client thread
53        process_t    * process = this->process;   // client process
54
55#if (DEBUG_SYS_OPENDIR || CONFIG_INSTRUMENTATION_SYSCALLS)
56uint64_t     tm_start = hal_get_cycles();
57#endif
58
59    // check DIR buffer in user space
60    error = vmm_get_vseg( process , (intptr_t)dirp, &vseg );
61
62        if( error )
63        {
64
65#if DEBUG_SYSCALLS_ERROR
66printk("\n[ERROR] in %s / thread[%x,%x] : DIR buffer %x unmapped\n",
67__FUNCTION__ , process->pid , this->trdid, dirp );
68vmm_display( process , false );
69#endif
70                this->errno = EINVAL;
71                return -1;
72        }       
73
74    // check pathname length
75    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
76    {
77
78#if DEBUG_SYSCALLS_ERROR
79printk("\n[ERROR] in %s / thread[%x,%x] : pathname too long\n",
80 __FUNCTION__ , process->pid , this->trdid );
81#endif
82        this->errno = ENFILE;
83        return -1;
84    }
85
86    // copy pathname in kernel space
87    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
88
89#if DEBUG_SYS_OPENDIR
90if( DEBUG_SYS_OPENDIR < tm_start )
91printk("\n[%s] thread[%x,%x] enter for directory <%s> / cycle %d\n",
92__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_start );
93#endif
94
95    // compute root inode for pathname
96    if( kbuf[0] == '/' )                        // absolute path
97    {
98        // use extended pointer on VFS root inode
99        root_inode_xp = process->vfs_root_xp;
100    }
101    else                                        // relative path
102    {
103        // get cluster and local pointer on reference process
104        xptr_t      ref_xp  = process->ref_xp;
105        process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
106        cxy_t       ref_cxy = GET_CXY( ref_xp );
107
108        // use extended pointer on CWD inode
109        root_inode_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->cwd_xp ) );
110    }
111
112    // get extended pointer on directory inode
113    error = vfs_lookup( root_inode_xp,
114                        kbuf,
115                        0,
116                        &inode_xp,
117                        NULL );
118    if( error )
119        {
120
121#if DEBUG_SYSCALLS_ERROR
122printk("\n[ERROR] in %s / thread[%x,%x] : cannot found directory <%s>\n",
123__FUNCTION__ , process->pid , this->trdid , kbuf );
124#endif
125                this->errno = ENFILE;
126                return -1;
127        }
128   
129    // check inode type
130    inode_ptr  = GET_PTR( inode_xp );
131    inode_cxy  = GET_CXY( inode_xp );
132    inode_type = hal_remote_l32( XPTR( inode_cxy , &inode_ptr->type ) );
133
134    if( inode_type != INODE_TYPE_DIR )
135        {
136
137#if DEBUG_SYSCALLS_ERROR
138printk("\n[ERROR] in %s / thread[%x,%x] : cannot found directory <%s>\n",
139__FUNCTION__ , process->pid , this->trdid , kbuf );
140#endif
141                this->errno = ENFILE;
142                return -1;
143        }
144   
145    // create a new user_dir_t structure in inode cluster
146    // and get the user space pointer on dirent array
147    if( inode_cxy == local_cxy )
148    {
149        dir_ptr = user_dir_create( inode_ptr );
150    }
151    else
152    {
153        rpc_user_dir_create_client( inode_cxy,
154                                    inode_ptr,
155                                    &dir_ptr );
156    }
157
158    if( dir_ptr == NULL )
159        {
160
161#if DEBUG_SYSCALLS_ERROR
162printk("\n[ERROR] in %s / thread[%x,%x] : cannot create user_dir for <%s>\n",
163__FUNCTION__ , process->pid , this->trdid , kbuf );
164#endif
165                this->errno = ENFILE;
166                return -1;
167        }
168   
169    // get ident from user_dir structure
170    ident = (intptr_t)hal_remote_lpt( XPTR( inode_cxy , &dir_ptr->ident ) );
171
172    // set ident value in user buffer
173    hal_copy_to_uspace( dirp , &ident , sizeof(intptr_t) );
174
175    hal_fence();
176
177#if (DEBUG_SYS_OPENDIR || CONFIG_INSTRUMENTATION_SYSCALLS)
178uint64_t     tm_end = hal_get_cycles();
179#endif
180
181#if DEBUG_SYS_OPENDIR
182if( DEBUG_SYS_OPENDIR < tm_end )
183printk("\n[%s] thread[%x,%x] exit for directory <%s> / cycle %d\n",
184__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_end );
185#endif
186 
187#if CONFIG_INSTRUMENTATION_SYSCALLS
188hal_atomic_add( &syscalls_cumul_cost[SYS_OPENDIR] , tm_end - tm_start );
189hal_atomic_add( &syscalls_occurences[SYS_OPENDIR] , 1 );
190#endif
191
192        return 0;
193
194}  // end sys_opendir()
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