source: trunk/kernel/syscalls/sys_stat.c@ 604

Last change on this file since 604 was 604, checked in by alain, 8 years ago

Improve the FAT32 file system to support cat, rm, cp commands.
File size: 4.9 KB
Line 
1/*
2 * sys_stat.c - Return statistics on a file or 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 <hal_kernel_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#include <syscalls.h>
35
36/////////////////////////////////////
37int sys_stat( char * pathname,
38 struct stat * u_stat )
39{
40 error_t error;
41 vseg_t * vseg; // for user space checking
42 struct stat k_stat; // in kernel space
43 xptr_t inode_xp; // extended pointer on target inode
44
45 char kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
46
47 thread_t * this = CURRENT_THREAD;
48 process_t * process = this->process;
49
50#if (DEBUG_SYS_STAT || CONFIG_INSTRUMENTATION_SYSCALLS)
51uint64_t tm_start = hal_get_cycles();
52#endif
53
54 // check stat structure in user space
55 error = vmm_get_vseg( process , (intptr_t)u_stat , &vseg );
56
57 if( error )
58 {
59
60#if DEBUG_SYSCALLS_ERROR
61printk("\n[ERROR] in %s / thread[%x,%x] : stat structure unmapped\n",
62__FUNCTION__ , process->pid , this->trdid );
63vmm_display( process , false );
64#endif
65 this->errno = EINVAL;
66 return -1;
67 }
68
69 // check pathname length
70 if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
71 {
72
73#if DEBUG_SYSCALLS_ERROR
74printk("\n[ERROR] in %s / thread[%x,%x] : pathname too long\n",
75 __FUNCTION__ , process->pid , this->trdid );
76#endif
77 this->errno = ENFILE;
78 return -1;
79 }
80
81 // copy pathname in kernel space
82 hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
83
84#if DEBUG_SYS_STAT
85if( DEBUG_SYS_STAT < tm_start )
86printk("\n[%s] thread[%x,%x] enter for file <%s> / cycle %d\n",
87__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_start );
88#endif
89
90 // get cluster and local pointer on reference process
91 xptr_t ref_xp = process->ref_xp;
92 process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
93 cxy_t ref_cxy = GET_CXY( ref_xp );
94
95 // get extended pointer on cwd inode
96 xptr_t cwd_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
97
98 // get the cwd lock in read mode from reference process
99 remote_rwlock_rd_acquire( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
100
101 // get extended pointer on remote file descriptor
102 error = vfs_lookup( cwd_xp,
103 kbuf,
104 0,
105 &inode_xp );
106
107 // release the cwd lock
108 remote_rwlock_rd_release( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
109
110 if( error )
111 {
112
113#if DEBUG_SYSCALLS_ERROR
114printk("\n[ERROR] in %s / thread[%x,%x] : cannot found file <%s>\n",
115__FUNCTION__ , process->pid , this->trdid , pathname );
116#endif
117 this->errno = ENFILE;
118 return -1;
119 }
120
121#if (DEBUG_SYS_STAT & 1)
122if( DEBUG_SYS_STAT < tm_start )
123printk("\n[%s] thread[%x,%x] got inode %x in cluster %x for <%s>\n",
124__FUNCTION__, process->pid, this->trdid, GET_PTR(inode_xp), GET_CXY(inode_xp), kbuf );
125#endif
126
127 // call VFS function to get stat info
128 error = vfs_stat( inode_xp,
129 &k_stat );
130 if( error )
131 {
132
133#if DEBUG_SYSCALLS_ERROR
134printk("\n[ERROR] in %s / thread[%x,%x] : cannot get stats for inode <%s>\n",
135__FUNCTION__ , process->pid , this->trdid , pathname );
136#endif
137 this->errno = ENFILE;
138 return -1;
139 }
140
141#if (DEBUG_SYS_STAT & 1)
142if( DEBUG_SYS_STAT < tm_start )
143printk("\n[%s] thread[%x,%x] set kstat : inum %d / size %d / mode %d\n",
144__FUNCTION__, process->pid, this->trdid, k_stat.st_ino, k_stat.st_size, k_stat.st_mode );
145#endif
146
147 // copy k_stat to u_stat
148 hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
149
150 hal_fence();
151
152#if (DEBUG_SYS_STAT || CONFIG_INSTRUMENTATION_SYSCALLS)
153uint64_t tm_end = hal_get_cycles();
154#endif
155
156#if DEBUG_SYS_STAT
157if( DEBUG_SYS_STAT < tm_end )
158printk("\n[%s] thread[%x,%x] exit for file <%s> / size %d / mode %d / cycle %d\n",
159__FUNCTION__, process->pid, this->trdid, kbuf,
160k_stat.st_size, k_stat.st_mode, (uint32_t)tm_end );
161#endif
162
163#if CONFIG_INSTRUMENTATION_SYSCALLS
164hal_atomic_add( &syscalls_cumul_cost[SYS_STAT] , tm_end - tm_start );
165hal_atomic_add( &syscalls_occurences[SYS_STAT] , 1 );
166#endif
167
168 return 0;
169
170} // end sys_stat()
171
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