source: rtems/cpukit/libcsupport/src/mount.c @ 00bf6744

4.10
Last change on this file since 00bf6744 was 00bf6744, checked in by Sebastian Huber <sebastian.huber@…>, on Jul 1, 2010 at 2:10:54 PM

2010-06-07 Sebastian Huber <sebastian.huber@…>

  • libcsupport/include/rtems/libio_.h: Declare rtems_filesystem_mount_table_control.
  • libcsupport/include/rtems/libio.h: Removed rtems_filesystem_table_first(), rtems_filesystem_table_next() and rtems_filesystem_table_node_t declarations. Declare rtems_per_filesystem_routine, rtems_filesystem_iterate() and rtems_filesystem_get_mount_handler().
  • libcsupport/src/mount.c: Added rtems_filesystem_mounts_first() and rtems_filesystem_mounts_next(). Simplify mount(). Removed rtems_filesystem_mount_table_control_init. Use rtems_filesystem_get_mount_handler().
  • libcsupport/src/mount-mgr.c: Removed rtems_filesystem_mounts_first() and rtems_filesystem_mounts_next(). Added rtems_filesystem_iterate() and rtems_filesystem_get_mount_handler(). Use rtems_libio_lock() and rtems_libio_unlock();
  • sapi/include/confdefs.h, libmisc/shell/main_mount.c: Update for mount API changes.

2010-06-07 Bharath Suri <bharath.s.jois@…>

  • libcsupport/include/rtems/libio_.h: Removed macros rtems_filesystem_is_separator rtems_filesystem_get_start_loc rtems_filesystem_get_sym_start_loc and added them as files under libcsupport/src/
  • libcsupport/src/: Added new files libcsupport/src/sup_fs_get_start_loc.c libcsupport/src/sup_fs_get_sym_start_loc.c libcsupport/src/sup_fs_is_separator.c
  • libcsupport/Makefile.am: Changes to accommodate new files under libcsupport/src/
  • Property mode set to 100644
File size: 8.4 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 *  Copyright (c) 2010 embedded brains GmbH.
14 *
15 *  The license and distribution terms for this file may be
16 *  found in the file LICENSE in this distribution or at
17 *  http://www.rtems.com/license/LICENSE.
18 *
19 *  $Id$
20 */
21
22#if HAVE_CONFIG_H
23#include "config.h"
24#endif
25
26#include <sys/types.h>
27#include <sys/stat.h>
28#include <rtems/chain.h>
29#include <rtems/seterr.h>
30#include <fcntl.h>
31#include <unistd.h>
32#include <errno.h>
33#include <stdlib.h>
34#include <string.h>
35#include <assert.h>
36
37#include <rtems/libio_.h>
38
39/*
40 * Mount table list.
41 */
42RTEMS_CHAIN_DEFINE_EMPTY(rtems_filesystem_mount_table_control);
43
44/*
45 * Default pathconfs.
46 */
47const rtems_filesystem_limits_and_options_t rtems_filesystem_default_pathconf = {
48   5,    /* link_max: count */
49   128,  /* max_canon: max formatted input line size */
50   7,    /* max_input: max input line size */
51   255,  /* name_max: max name */
52   255,  /* path_max: max path */
53   1024, /* pipe_buf: pipe buffer size */
54   0,    /* posix_async_io: async IO supported on fs, 0=no, 1=yes */
55   0 ,   /* posix_chown_restrictions: can chown: 0=no, 1=yes */
56   1,    /* posix_no_trunc: error on filenames > max name, 0=no, 1=yes */
57   0,    /* posix_prio_io: priority IO, 0=no, 1=yes */
58   0,    /* posix_sync_io: file can be sync'ed, 0=no, 1=yes */
59   0     /* posix_vdisable: special char processing, 0=no, 1=yes */
60};
61
62/*
63 *  Is_node_fs_root
64 *
65 *  This routine will run through the entries that currently exist in the
66 *  mount table chain. For each entry in the mount table chain it will
67 *  compare the mount tables root node to the node describing the selected
68 *  mount point. If any match is found true is returned else false is
69 *  returned.
70 *
71 */
72
73static bool Is_node_fs_root(
74  rtems_filesystem_location_info_t *loc
75)
76{
77  rtems_chain_node *node = NULL;
78
79  /*
80   * For each mount table entry
81   */
82  for ( node = rtems_chain_first( &rtems_filesystem_mount_table_control );
83        !rtems_chain_is_tail( &rtems_filesystem_mount_table_control, node );
84        node = rtems_chain_next( node ) ) {
85    rtems_filesystem_mount_table_entry_t *mount_table_entry =
86      (rtems_filesystem_mount_table_entry_t *) node;
87
88    if ( mount_table_entry->mt_fs_root.node_access == loc->node_access )
89      return true;
90  }
91
92  return false;
93}
94
95static rtems_filesystem_mount_table_entry_t *alloc_mount_table_entry(
96  const char *source,
97  const char *target,
98  const char *filesystemtype,
99  size_t *target_length_ptr
100)
101{
102  const char *target_str = target ? target : "/";
103  size_t filesystemtype_size = strlen( filesystemtype ) + 1;
104  size_t source_size = source ? strlen( source ) + 1 : 0;
105  size_t target_length = strlen( target_str );
106  size_t size = sizeof( rtems_filesystem_mount_table_entry_t )
107    + filesystemtype_size + source_size + target_length + 1;
108  rtems_filesystem_mount_table_entry_t *mt_entry = calloc( 1, size );
109
110  if ( mt_entry ) {
111    char *str = (char *) mt_entry + sizeof( *mt_entry );
112
113    mt_entry->type = str;
114    strcpy( str, filesystemtype );
115
116    if ( source ) {
117      str += filesystemtype_size;
118      mt_entry->dev = str;
119      strcpy( str, source );
120    }
121
122    str += source_size;
123    mt_entry->target = str;
124    strcpy( str, target );
125  }
126
127  *target_length_ptr = target_length;
128
129  return mt_entry;
130}
131
132/*
133 *  mount
134 *
135 *  This routine will attempt to mount a new file system at the specified
136 *  mount point. A series of tests will be run to determine if any of the
137 *  following reasons exist to prevent the mount operation:
138 *
139 *      1) The file system type or options are not valid
140 *      2) No new file system root node is specified
141 *      3) The selected file system has already been mounted
142 *      4) The mount point exists with the proper permissions to allow mounting
143 *      5) The selected mount point already has a file system mounted to it
144 *
145 */
146
147int mount(
148  const char                 *source,
149  const char                 *target,
150  const char                 *filesystemtype,
151  rtems_filesystem_options_t options,
152  const void                 *data
153)
154{
155  rtems_filesystem_fsmount_me_t mount_h = NULL;
156  rtems_filesystem_location_info_t      loc;
157  rtems_filesystem_mount_table_entry_t *mt_entry = NULL;
158  rtems_filesystem_location_info_t     *loc_to_free = NULL;
159  bool has_target = target != NULL;
160  size_t target_length = 0;
161
162  /*
163   *  Are the file system options valid?
164   */
165
166  if ( options != RTEMS_FILESYSTEM_READ_ONLY &&
167       options != RTEMS_FILESYSTEM_READ_WRITE )
168    rtems_set_errno_and_return_minus_one( EINVAL );
169
170  /*
171   *  Get mount handler
172   */
173  mount_h = rtems_filesystem_get_mount_handler( filesystemtype );
174  if ( !mount_h )
175    rtems_set_errno_and_return_minus_one( EINVAL );
176
177  /*
178   * Allocate a mount table entry
179   */
180  mt_entry = alloc_mount_table_entry(
181    source,
182    target,
183    filesystemtype,
184    &target_length
185  );
186  if ( !mt_entry )
187    rtems_set_errno_and_return_minus_one( ENOMEM );
188
189  mt_entry->mt_fs_root.mt_entry = mt_entry;
190  mt_entry->options = options;
191  mt_entry->pathconf_limits_and_options = rtems_filesystem_default_pathconf;
192
193  /*
194   *  The mount_point should be a directory with read/write/execute
195   *  permissions in the existing tree.
196   */
197
198  if ( has_target ) {
199    if ( rtems_filesystem_evaluate_path(
200           target, target_length, RTEMS_LIBIO_PERMS_RWX, &loc, true ) == -1 )
201      goto cleanup_and_bail;
202
203    loc_to_free = &loc;
204
205    /*
206     * Test for node_type_h
207     */
208
209    if (!loc.ops->node_type_h) {
210      errno =  ENOTSUP;
211      goto cleanup_and_bail;
212    }
213
214    /*
215     *  Test to see if it is a directory
216     */
217
218    if ( loc.ops->node_type_h( &loc ) != RTEMS_FILESYSTEM_DIRECTORY ) {
219      errno = ENOTDIR;
220      goto cleanup_and_bail;
221    }
222
223    /*
224     *  You can only mount one file system onto a single mount point.
225     */
226
227    if ( Is_node_fs_root(  &loc ) ){
228      errno = EBUSY;
229      goto cleanup_and_bail;
230    }
231
232    /*
233     *  This must be a good mount point, so move the location information
234     *  into the allocated mount entry.  Note:  the information that
235     *  may have been allocated in loc should not be sent to freenode
236     *  until the system is unmounted.  It may be needed to correctly
237     *  traverse the tree.
238     */
239
240    mt_entry->mt_point_node.node_access = loc.node_access;
241    mt_entry->mt_point_node.handlers = loc.handlers;
242    mt_entry->mt_point_node.ops = loc.ops;
243    mt_entry->mt_point_node.mt_entry = loc.mt_entry;
244
245    /*
246     *  This link to the parent is only done when we are dealing with system
247     *  below the base file system
248     */
249
250    if ( !loc.ops->mount_h ){
251      errno = ENOTSUP;
252      goto cleanup_and_bail;
253    }
254
255    if ( loc.ops->mount_h( mt_entry ) ) {
256      goto cleanup_and_bail;
257    }
258  } else {
259    /*
260     * Do we already have a base file system ?
261     */
262    if ( !rtems_chain_is_empty( &rtems_filesystem_mount_table_control ) ) {
263      errno = EINVAL;
264      goto cleanup_and_bail;
265    }
266
267    /*
268     *  This is a mount of the base file system --> The
269     *  mt_point_node.node_access will be left to null to indicate that this
270     *  is the root of the entire file system.
271     */
272  }
273
274  if ( (*mount_h)( mt_entry, data ) ) {
275    /*
276     * Try to undo the mount operation
277     */
278    if ( loc.ops->unmount_h ) {
279      loc.ops->unmount_h( mt_entry );
280    }
281    goto cleanup_and_bail;
282  }
283
284  /*
285   *  Add the mount table entry to the mount table chain
286   */
287  rtems_chain_append( &rtems_filesystem_mount_table_control,
288                      &mt_entry->Node );
289
290  if ( !has_target )
291    rtems_filesystem_root = mt_entry->mt_fs_root;
292
293  return 0;
294
295cleanup_and_bail:
296
297  free( mt_entry );
298
299  if ( loc_to_free )
300    rtems_filesystem_freenode( loc_to_free );
301
302  return -1;
303}
304
305/*
306 * Get the first entry in the mount table.
307 */
308rtems_filesystem_mount_table_entry_t *
309rtems_filesystem_mounts_first(
310  void
311)
312{
313  rtems_filesystem_mount_table_entry_t *entry = NULL;
314
315  if ( !rtems_chain_is_empty( &rtems_filesystem_mount_table_control ) )
316    entry = (rtems_filesystem_mount_table_entry_t *)
317      rtems_chain_first( &rtems_filesystem_mount_table_control );
318
319  return entry;
320}
321
322/*
323 * Get the next entry in the mount table.
324 */
325rtems_filesystem_mount_table_entry_t *
326rtems_filesystem_mounts_next(
327  rtems_filesystem_mount_table_entry_t *entry
328)
329{
330  if ( !entry )
331    return NULL;
332  return (rtems_filesystem_mount_table_entry_t *)
333    rtems_chain_next( &entry->Node );
334}
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