1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/*
* unmount() - Unmount a File System
*
* This routine is not defined in the POSIX 1003.1b standard but
* in some form is supported on most UNIX and POSIX systems. This
* routine is necessary to mount instantiations of a file system
* into the file system name space.
*
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <chain.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <rtems/libio_.h>
/*
* Data structures and routines private to mount/unmount pair.
*/
extern Chain_Control rtems_filesystem_mount_table_control;
int search_mt_for_mount_point(
rtems_filesystem_location_info_t *location_of_mount_point
);
rtems_boolean rtems_filesystem_nodes_equal(
const rtems_filesystem_location_info_t *loc1,
const rtems_filesystem_location_info_t *loc2
){
return ( loc1->node_access == loc2->node_access );
}
/*
* file_systems_below_this_mountpoint
*
* This routine will run through the entries that currently exist in the
* mount table chain. For each entry in the mount table chain it will
* compare the mount tables mt_fs_root to the new_fs_root_node. If any of the
* mount table file system root nodes matches the new file system root node
* this indicates that we are trying to mount a file system that has already
* been mounted. This is not a permitted operation. temp_loc is set to
* the root node of the file system being unmounted.
*/
rtems_boolean file_systems_below_this_mountpoint(
const char *path,
rtems_filesystem_location_info_t *fs_root_loc,
rtems_filesystem_mount_table_entry_t *fs_to_unmount
)
{
Chain_Node *the_node;
rtems_filesystem_mount_table_entry_t *the_mount_entry;
/*
* Search the mount table for any mount entries referencing this
* mount entry.
*/
for ( the_node = rtems_filesystem_mount_table_control.first;
!Chain_Is_tail( &rtems_filesystem_mount_table_control, the_node );
the_node = the_node->next ) {
the_mount_entry = ( rtems_filesystem_mount_table_entry_t * )the_node;
if (the_mount_entry->mt_point_node.mt_entry == fs_root_loc->mt_entry ) {
return TRUE;
}
}
return FALSE;
}
/*
* unmount
*
* This routine will attempt to unmount the file system that has been
* is mounted a path. If the operation is successful, 0 will
* be returned to the calling routine. Otherwise, 1 will be returned.
*/
int unmount(
const char *path
)
{
rtems_filesystem_location_info_t loc;
rtems_filesystem_location_info_t *fs_root_loc;
rtems_filesystem_location_info_t *fs_mount_loc;
rtems_filesystem_mount_table_entry_t *mt_entry;
/*
* Get
* The root node of the mounted filesytem.
* The node for the directory that the fileystem is mounted on.
* The mount entry that is being refered to.
*/
if ( rtems_filesystem_evaluate_path( path, 0x0, &loc, TRUE ) )
return -1;
mt_entry = loc.mt_entry;
fs_mount_loc = &mt_entry->mt_point_node;
fs_root_loc = &mt_entry->mt_fs_root;
/*
* Verify this is the root node for the file system to be unmounted.
*/
if ( !rtems_filesystem_nodes_equal( fs_root_loc, &loc) ){
rtems_filesystem_freenode( &loc );
set_errno_and_return_minus_one( EACCES );
}
/*
* Free the loc node and just use the nodes from the mt_entry .
*/
rtems_filesystem_freenode( &loc );
/*
* Verify Unmount is supported by both filesystems.
*/
if ( !fs_mount_loc->ops->unmount_h )
set_errno_and_return_minus_one( ENOTSUP );
if ( !fs_root_loc->ops->fsunmount_me_h )
set_errno_and_return_minus_one( ENOTSUP );
/*
* Verify the current node is not in this filesystem.
* XXX - Joel I have a question here wasn't code added
* that made the current node thread based instead
* of system based? I thought it was but it doesn't
* look like it in this version.
*/
if ( rtems_filesystem_current.mt_entry == mt_entry )
set_errno_and_return_minus_one( EBUSY );
/*
* Verify there are no file systems below the path specified
*/
if ( file_systems_below_this_mountpoint( path, fs_root_loc, mt_entry ) != 0 )
set_errno_and_return_minus_one( EBUSY );
/*
* Run the file descriptor table to determine if there are any file
* descriptors that are currently active and reference nodes in the
* file system that we are trying to unmount
*/
if ( rtems_libio_is_open_files_in_fs( mt_entry ) == 1 )
set_errno_and_return_minus_one( EBUSY );
/*
* Allow the file system being unmounted on to do its cleanup.
* If it fails it will set the errno to the approprate value
* and the fileystem will not be modified.
*/
if (( fs_mount_loc->ops->unmount_h )( mt_entry ) != 0 )
return -1;
/*
* Allow the mounted filesystem to unmark the use of the root node.
*
* Run the unmount function for the subordinate file system.
*
* If we fail to unmount the filesystem remount it on the base filesystems
* directory node.
*
* NOTE: Fatal error is called in a case which should never happen
* This was response was questionable but the best we could
* come up with.
*/
if ((fs_root_loc->ops->fsunmount_me_h )( mt_entry ) != 0){
if (( fs_mount_loc->ops->mount_h )( mt_entry ) != 0 )
rtems_fatal_error_occurred( 0 );
return -1;
}
/*
* Extract the mount table entry from the chain
*/
Chain_Extract( ( Chain_Node * ) mt_entry );
/*
* Free the memory node that was allocated in mount
* Free the memory associated with the extracted mount table entry.
*/
rtems_filesystem_freenode( fs_mount_loc );
free( mt_entry );
return 0;
}
|
