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/**
* @file
*
* @brief Mounts a File System
* @ingroup FileSystemTypesAndMount
*/
/*
* COPYRIGHT (c) 1989-2010.
* On-Line Applications Research Corporation (OAR).
*
* Copyright (c) 2010-2012 embedded brains GmbH.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <rtems/libio_.h>
RTEMS_CHAIN_DEFINE_EMPTY(rtems_filesystem_mount_table);
const rtems_filesystem_limits_and_options_t rtems_filesystem_default_pathconf = {
5, /* link_max: count */
128, /* max_canon: max formatted input line size */
7, /* max_input: max input line size */
255, /* name_max: max name */
255, /* path_max: max path */
1024, /* pipe_buf: pipe buffer size */
0, /* posix_async_io: async IO supported on fs, 0=no, 1=yes */
0 , /* posix_chown_restrictions: can chown: 0=no, 1=yes */
1, /* posix_no_trunc: error on filenames > max name, 0=no, 1=yes */
0, /* posix_prio_io: priority IO, 0=no, 1=yes */
0, /* posix_sync_io: file can be sync'ed, 0=no, 1=yes */
0 /* posix_vdisable: special char processing, 0=no, 1=yes */
};
static rtems_filesystem_mount_table_entry_t *alloc_mount_table_entry(
const char *source_or_null,
const char *target_or_null,
const char *filesystemtype,
size_t *target_length_ptr
)
{
const char *target = target_or_null != NULL ? target_or_null : "/";
size_t filesystemtype_size = strlen( filesystemtype ) + 1;
size_t source_size = source_or_null != NULL ?
strlen( source_or_null ) + 1 : 0;
size_t target_size = strlen( target ) + 1;
size_t size = sizeof( rtems_filesystem_mount_table_entry_t )
+ filesystemtype_size + source_size + target_size
+ sizeof( rtems_filesystem_global_location_t );
rtems_filesystem_mount_table_entry_t *mt_entry = calloc( 1, size );
if ( mt_entry != NULL ) {
rtems_filesystem_global_location_t *mt_fs_root =
(rtems_filesystem_global_location_t *)
((char *) mt_entry + sizeof( *mt_entry ));
char *str = (char *) mt_fs_root + sizeof( *mt_fs_root );
memcpy( str, filesystemtype, filesystemtype_size );
mt_entry->type = str;
str += filesystemtype_size;
if ( source_or_null != NULL ) {
memcpy( str, source_or_null, source_size );
mt_entry->dev = str;
str += source_size;
}
memcpy( str, target, target_size );
mt_entry->target = str;
mt_entry->mounted = true;
mt_entry->mt_fs_root = mt_fs_root;
mt_entry->pathconf_limits_and_options = &rtems_filesystem_default_pathconf;
mt_fs_root->location.mt_entry = mt_entry;
mt_fs_root->reference_count = 1;
rtems_chain_initialize(
&mt_entry->location_chain,
mt_fs_root,
1,
sizeof(*mt_fs_root)
);
}
*target_length_ptr = target_size - 1;
return mt_entry;
}
static int register_subordinate_file_system(
rtems_filesystem_mount_table_entry_t *mt_entry,
const char *target
)
{
int rv = 0;
rtems_filesystem_eval_path_context_t ctx;
int eval_flags = RTEMS_FS_PERMS_RWX
| RTEMS_FS_FOLLOW_LINK;
rtems_filesystem_location_info_t *currentloc =
rtems_filesystem_eval_path_start( &ctx, target, eval_flags );
if ( !rtems_filesystem_location_is_instance_root( currentloc ) ) {
rtems_filesystem_location_info_t targetloc;
rtems_filesystem_global_location_t *mt_point_node;
rtems_filesystem_eval_path_extract_currentloc( &ctx, &targetloc );
mt_point_node = rtems_filesystem_location_transform_to_global( &targetloc );
mt_entry->mt_point_node = mt_point_node;
rv = (*mt_point_node->location.mt_entry->ops->mount_h)( mt_entry );
if ( rv == 0 ) {
rtems_filesystem_mt_lock();
rtems_chain_append_unprotected(
&rtems_filesystem_mount_table,
&mt_entry->mt_node
);
rtems_filesystem_mt_unlock();
} else {
rtems_filesystem_global_location_release( mt_point_node, true );
}
} else {
rtems_filesystem_eval_path_error( &ctx, EBUSY );
rv = -1;
}
rtems_filesystem_eval_path_cleanup( &ctx );
return rv;
}
static int register_root_file_system(
rtems_filesystem_mount_table_entry_t *mt_entry
)
{
int rv = 0;
rtems_filesystem_mt_lock();
if ( rtems_chain_is_empty( &rtems_filesystem_mount_table ) ) {
rtems_chain_append_unprotected(
&rtems_filesystem_mount_table,
&mt_entry->mt_node
);
} else {
errno = EINVAL;
rv = -1;
}
rtems_filesystem_mt_unlock();
if ( rv == 0 ) {
rtems_filesystem_global_location_t *new_fs_root =
rtems_filesystem_global_location_obtain( &mt_entry->mt_fs_root );
rtems_filesystem_global_location_t *new_fs_current =
rtems_filesystem_global_location_obtain( &mt_entry->mt_fs_root );
rtems_filesystem_global_location_assign(
&rtems_filesystem_root,
new_fs_root
);
rtems_filesystem_global_location_assign(
&rtems_filesystem_current,
new_fs_current
);
}
return rv;
}
int mount(
const char *source,
const char *target,
const char *filesystemtype,
rtems_filesystem_options_t options,
const void *data
)
{
int rv = 0;
if (
options == RTEMS_FILESYSTEM_READ_ONLY
|| options == RTEMS_FILESYSTEM_READ_WRITE
) {
rtems_filesystem_fsmount_me_t fsmount_me_h =
rtems_filesystem_get_mount_handler( filesystemtype );
if ( fsmount_me_h != NULL ) {
size_t target_length = 0;
rtems_filesystem_mount_table_entry_t *mt_entry = alloc_mount_table_entry(
source,
target,
filesystemtype,
&target_length
);
if ( mt_entry != NULL ) {
mt_entry->writeable = options == RTEMS_FILESYSTEM_READ_WRITE;
rv = (*fsmount_me_h)( mt_entry, data );
if ( rv == 0 ) {
if ( target != NULL ) {
rv = register_subordinate_file_system( mt_entry, target );
} else {
rv = register_root_file_system( mt_entry );
}
if ( rv != 0 ) {
(*mt_entry->ops->fsunmount_me_h)( mt_entry );
}
}
if ( rv != 0 ) {
free( mt_entry );
}
} else {
errno = ENOMEM;
rv = -1;
}
} else {
errno = EINVAL;
rv = -1;
}
} else {
errno = EINVAL;
rv = -1;
}
return rv;
}
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