/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @brief Unmount a File System
* @ingroup libcsupport
*/
/*
* COPYRIGHT (c) 1989-2010.
* On-Line Applications Research Corporation (OAR).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef 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;
}