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/**
* @file
*
* @brief Unmount a File System
* @ingroup libcsupport
*/
/*
* COPYRIGHT (c) 1989-2010.
* 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.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <rtems/libio_.h>
static bool contains_root_or_current_directory(
const rtems_filesystem_mount_table_entry_t *mt_entry
)
{
const rtems_filesystem_location_info_t *root =
&rtems_filesystem_root->location;
const rtems_filesystem_location_info_t *current =
&rtems_filesystem_current->location;
return mt_entry == root->mt_entry || mt_entry == current->mt_entry;
}
/**
* 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.
*/
int unmount( const char *path )
{
int rv = 0;
rtems_filesystem_eval_path_context_t ctx;
int eval_flags = RTEMS_FS_FOLLOW_LINK;
const rtems_filesystem_location_info_t *currentloc =
rtems_filesystem_eval_path_start( &ctx, path, eval_flags );
rtems_filesystem_mount_table_entry_t *mt_entry = currentloc->mt_entry;
if ( rtems_filesystem_location_is_instance_root( currentloc ) ) {
if ( !contains_root_or_current_directory( mt_entry ) ) {
const rtems_filesystem_operations_table *mt_point_ops =
mt_entry->mt_point_node->location.mt_entry->ops;
rv = (*mt_point_ops->unmount_h)( mt_entry );
if ( rv == 0 ) {
rtems_id self_task_id = rtems_task_self();
rtems_filesystem_mt_entry_declare_lock_context( lock_context );
rtems_filesystem_mt_entry_lock( lock_context );
mt_entry->unmount_task = self_task_id;
mt_entry->mounted = false;
rtems_filesystem_mt_entry_unlock( lock_context );
}
} else {
errno = EBUSY;
rv = -1;
}
} else {
errno = EACCES;
rv = -1;
}
rtems_filesystem_eval_path_cleanup( &ctx );
if ( rv == 0 ) {
rtems_status_code sc = rtems_event_transient_receive(
RTEMS_WAIT,
RTEMS_NO_TIMEOUT
);
if ( sc != RTEMS_SUCCESSFUL ) {
rtems_fatal_error_occurred( 0xdeadbeef );
}
}
return rv;
}
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