source: rtems/cpukit/libcsupport/src/mount.c @ 4b0d1ab

4.104.114.84.95
Last change on this file since 4b0d1ab was 4b0d1ab, checked in by Jennifer Averett <Jennifer.Averett@…>, on Nov 17, 2000 at 6:42:02 PM

2000-11-17 Jennifer Averret <jennifer@…>

  • libc/mount.c (search_mt_for_mount_point): Deleted routine.
  • libc/mount.c (Is_node_fs_root): Replacement for above that accounts for the imaginary root node being returned by the filesystem evaluation routine.
  • libc/unmount.c (unmount): Account for imaginary root node being returned and improved variable names to clarify code.
  • libc/unmount.c (file_systems_below_this_mountpoint): Body of routine replaced to account for imaginary root node being returned.
  • Property mode set to 100644
File size: 6.3 KB
Line 
1/*
2 *  mount()
3 *
4 *  XXX
5 *
6 *  XXX make sure no required ops are NULL
7 *  XXX make sure no optional ops you are using are NULL
8 *  XXX unmount should be required.
9 *
10 *  COPYRIGHT (c) 1989-1999.
11 *  On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.OARcorp.com/rtems/license.html.
16 *
17 *  $Id$
18 */
19
20#include <sys/types.h>
21#include <sys/stat.h>
22#include <chain.h>
23#include <fcntl.h>
24#include <unistd.h>
25#include <errno.h>
26#include <stdlib.h>
27#include <string.h>
28#include <assert.h>
29
30#include <rtems/libio_.h>
31
32Chain_Control rtems_filesystem_mount_table_control;
33
34/*
35 *  Prototypes that probably should be somewhere else.
36 */
37
38int init_fs_mount_table( void );
39static int Is_node_fs_root(
40  rtems_filesystem_location_info_t  *loc
41);
42
43
44/*
45 *  XXX
46 */
47
48#define FOUND      0
49#define NOT_FOUND -1
50
51/*
52 *  mount
53 *
54 *  This routine will attempt to mount a new file system at the specified
55 *  mount point. A series of tests will be run to determine if any of the
56 *  following reasons exist to prevent the mount operation:
57 *
58 *      1) The file system type or options are not valid
59 *      2) No new file system root node is specified
60 *      3) The selected file system has already been mounted
61 *      4) The mount point exists with the proper permissions to allow mounting
62 *      5) The selected mount point already has a file system mounted to it
63 *
64 */
65
66int mount(
67  rtems_filesystem_mount_table_entry_t **mt_entry,
68  rtems_filesystem_operations_table    *fs_ops,
69  rtems_filesystem_options_t            options,
70  char                                 *device,
71  char                                 *mount_point
72)
73{
74  rtems_filesystem_location_info_t      loc;
75  rtems_filesystem_mount_table_entry_t *temp_mt_entry;
76  rtems_filesystem_location_info_t     *loc_to_free = NULL;
77
78/* XXX add code to check for required operations */
79
80  /*
81   *  Is there a file system operations table?
82   */
83
84  if ( fs_ops == NULL ) {
85    errno = EINVAL;
86    return -1;
87  }
88
89  /*
90   *  Are the file system options valid?
91   */
92
93  if ( options != RTEMS_FILESYSTEM_READ_ONLY && 
94       options != RTEMS_FILESYSTEM_READ_WRITE ) {
95    errno = EINVAL;
96    return -1;
97  }
98
99  /*
100   * Allocate a mount table entry
101   */
102
103   temp_mt_entry = malloc( sizeof(rtems_filesystem_mount_table_entry_t) );
104
105   if ( !temp_mt_entry ) {
106     errno = ENOMEM;
107     return -1;
108   }
109
110   temp_mt_entry->mt_fs_root.mt_entry = temp_mt_entry;
111   temp_mt_entry->options = options;
112   if ( device )
113     strcpy( temp_mt_entry->dev, device );
114   else
115     temp_mt_entry->dev = 0;
116
117  /*
118   *  The mount_point should be a directory with read/write/execute
119   *  permissions in the existing tree.
120   */
121
122  if ( mount_point ) {
123
124    if ( rtems_filesystem_evaluate_path( 
125            mount_point, RTEMS_LIBIO_PERMS_RWX, &loc, TRUE ) == -1 )
126      goto cleanup_and_bail;
127
128    /*
129     *  Test to see if it is a directory
130     */
131
132    loc_to_free = &loc;
133    if ( loc.ops->node_type_h( &loc ) != RTEMS_FILESYSTEM_DIRECTORY ) {
134      errno = ENOTDIR;
135      goto cleanup_and_bail;
136    }
137
138    /*
139     *  You can only mount one file system onto a single mount point.
140     */
141
142    if ( Is_node_fs_root(  &loc ) ){
143      errno = EBUSY;
144      goto cleanup_and_bail;
145    }
146 
147    /*
148     *  This must be a good mount point, so move the location information
149     *  into the allocated mount entry.  Note:  the information that
150     *  may have been allocated in loc should not be sent to freenode
151     *  until the system is unmounted.  It may be needed to correctly
152     *  traverse the tree.
153     */
154
155    temp_mt_entry->mt_point_node.node_access = loc.node_access;
156    temp_mt_entry->mt_point_node.handlers = loc.handlers;
157    temp_mt_entry->mt_point_node.ops = loc.ops;
158    temp_mt_entry->mt_point_node.mt_entry = loc.mt_entry;
159
160    /*
161     *  This link to the parent is only done when we are dealing with system
162     *  below the base file system
163     */
164
165    if ( !loc.ops->mount_h ){
166      errno = ENOTSUP;
167      goto cleanup_and_bail;
168    }
169
170    if ( loc.ops->mount_h( temp_mt_entry ) ) {
171      goto cleanup_and_bail;
172    }
173  } else {
174
175    /*
176     *  This is a mount of the base file system --> The
177     *  mt_point_node.node_access will be set to null to indicate that this
178     *  is the root of the entire file system.
179     */
180
181    temp_mt_entry->mt_fs_root.node_access = NULL;
182    temp_mt_entry->mt_fs_root.handlers = NULL;
183    temp_mt_entry->mt_fs_root.ops = NULL;
184
185    temp_mt_entry->mt_point_node.node_access = NULL;
186    temp_mt_entry->mt_point_node.handlers = NULL;
187    temp_mt_entry->mt_point_node.ops = NULL;
188    temp_mt_entry->mt_point_node.mt_entry = NULL;
189  }
190
191  if ( !fs_ops->fsmount_me_h ) {
192    errno = ENOTSUP;
193    goto cleanup_and_bail;
194  }
195
196  if ( fs_ops->fsmount_me_h( temp_mt_entry ) )
197    goto cleanup_and_bail;
198
199  /*
200   *  Add the mount table entry to the mount table chain
201   */
202
203  Chain_Append( &rtems_filesystem_mount_table_control, &temp_mt_entry->Node );
204
205  *mt_entry = temp_mt_entry;
206
207  return 0;
208
209cleanup_and_bail:
210
211  free( temp_mt_entry );
212 
213  if ( loc_to_free )
214    rtems_filesystem_freenode( loc_to_free );
215
216  return -1;
217}
218
219
220
221/*
222 *  init_fs_mount_table
223 *
224 *  This routine will initialize the chain control element that manages the
225 *  mount table chain.
226 */
227
228int init_fs_mount_table()
229{
230  Chain_Initialize_empty ( &rtems_filesystem_mount_table_control );
231  return 0;
232}
233
234/*
235 *  Is_node_fs_root
236 *
237 *  This routine will run through the entries that currently exist in the
238 *  mount table chain. For each entry in the mount table chain it will
239 *  compare the mount tables root node to the node describing the selected
240 *  mount point. If any match is found true is returned else false is
241 *  returned.
242 *
243 */
244
245static int Is_node_fs_root(
246  rtems_filesystem_location_info_t  *loc
247)
248{
249  Chain_Node                           *the_node;
250  rtems_filesystem_mount_table_entry_t *the_mount_entry;
251
252  /*
253   * For each mount table entry
254   */
255
256  for ( the_node = rtems_filesystem_mount_table_control.first;
257        !Chain_Is_tail( &rtems_filesystem_mount_table_control, the_node );
258        the_node = the_node->next ) {
259     the_mount_entry = (rtems_filesystem_mount_table_entry_t *) the_node;
260     if ( the_mount_entry->mt_fs_root.node_access  == loc->node_access )
261        return TRUE;
262  }
263  return FALSE;
264}
Note: See TracBrowser for help on using the repository browser.