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/*
* Copyright (c) 2012 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#define __RTEMS_VIOLATE_KERNEL_VISIBILITY__
#include <stdlib.h>
#include <rtems/libio_.h>
#include <rtems/score/thread.h>
static rtems_filesystem_global_location_t *deferred_released_global_locations;
rtems_filesystem_location_info_t *rtems_filesystem_location_copy(
rtems_filesystem_location_info_t *dst,
const rtems_filesystem_location_info_t *src
)
{
dst->node_access = src->node_access;
dst->node_access_2 = src->node_access_2;
dst->handlers = src->handlers;
dst->ops = src->ops;
dst->mt_entry = src->mt_entry;
rtems_filesystem_location_add_to_mt_entry(dst);
return dst;
}
void rtems_filesystem_location_detach(
rtems_filesystem_location_info_t *detach
)
{
rtems_filesystem_location_free(detach);
rtems_filesystem_location_initialize_to_null(detach);
}
void rtems_filesystem_location_copy_and_detach(
rtems_filesystem_location_info_t *copy,
rtems_filesystem_location_info_t *detach
)
{
rtems_filesystem_location_copy(copy, detach);
rtems_filesystem_location_remove_from_mt_entry(detach);
rtems_filesystem_location_initialize_to_null(detach);
}
rtems_filesystem_global_location_t *rtems_filesystem_location_transform_to_global(
rtems_filesystem_location_info_t *loc
)
{
rtems_filesystem_global_location_t *global_loc = malloc(sizeof(*global_loc));
if (global_loc != NULL) {
global_loc->reference_count = 1;
global_loc->deferred_released_next = NULL;
global_loc->deferred_released_count = 0;
rtems_filesystem_location_copy(&global_loc->location, loc);
rtems_filesystem_location_remove_from_mt_entry(loc);
} else {
rtems_filesystem_location_free(loc);
global_loc = rtems_filesystem_global_location_obtain_null();
errno = ENOMEM;
}
return global_loc;
}
void rtems_filesystem_global_location_assign(
rtems_filesystem_global_location_t **lhs_global_loc_ptr,
rtems_filesystem_global_location_t *rhs_global_loc
)
{
rtems_filesystem_mt_entry_declare_lock_context(lock_context);
rtems_filesystem_global_location_t *lhs_global_loc;
rtems_filesystem_mt_entry_lock(lock_context);
lhs_global_loc = *lhs_global_loc_ptr;
*lhs_global_loc_ptr = rhs_global_loc;
rtems_filesystem_mt_entry_unlock(lock_context);
rtems_filesystem_global_location_release(lhs_global_loc);
}
static void release_with_count(
rtems_filesystem_global_location_t *global_loc,
int count
)
{
rtems_filesystem_mount_table_entry_t *mt_entry =
global_loc->location.mt_entry;
rtems_filesystem_mt_entry_declare_lock_context(lock_context);
bool do_free;
bool do_unmount;
rtems_filesystem_mt_entry_lock(lock_context);
global_loc->reference_count -= count;
do_free = global_loc->reference_count == 0;
do_unmount = rtems_filesystem_is_ready_for_unmount(mt_entry);
rtems_filesystem_mt_entry_unlock(lock_context);
if (do_free) {
rtems_filesystem_location_free(&global_loc->location);
free(global_loc);
}
if (do_unmount) {
rtems_filesystem_do_unmount(mt_entry);
}
}
static void deferred_release(void)
{
rtems_filesystem_global_location_t *current = NULL;
do {
int count = 0;
_Thread_Disable_dispatch();
current = deferred_released_global_locations;
if (current != NULL) {
deferred_released_global_locations = current->deferred_released_next;
count = current->deferred_released_count;
current->deferred_released_next = NULL;
current->deferred_released_count = 0;
}
_Thread_Enable_dispatch();
if (current != NULL) {
release_with_count(current, count);
}
} while (current != NULL);
}
rtems_filesystem_global_location_t *rtems_filesystem_global_location_obtain(
rtems_filesystem_global_location_t *const *global_loc_ptr
)
{
rtems_filesystem_mt_entry_declare_lock_context(lock_context);
rtems_filesystem_global_location_t *global_loc;
if (deferred_released_global_locations != NULL) {
deferred_release();
}
rtems_filesystem_mt_entry_lock(lock_context);
global_loc = *global_loc_ptr;
if (global_loc == NULL || !global_loc->location.mt_entry->mounted) {
global_loc = &rtems_filesystem_global_location_null;
errno = ENXIO;
}
++global_loc->reference_count;
rtems_filesystem_mt_entry_unlock(lock_context);
return global_loc;
}
void rtems_filesystem_global_location_release(
rtems_filesystem_global_location_t *global_loc
)
{
if (!_Thread_Dispatch_in_critical_section()) {
release_with_count(global_loc, 1);
} else {
if (global_loc->deferred_released_count == 0) {
rtems_filesystem_global_location_t *head =
deferred_released_global_locations;
global_loc->deferred_released_count = 1;
global_loc->deferred_released_next = head;
deferred_released_global_locations = global_loc;
} else {
++global_loc->deferred_released_count;
}
}
}
void rtems_filesystem_location_remove_from_mt_entry(
rtems_filesystem_location_info_t *loc
)
{
rtems_filesystem_mt_entry_declare_lock_context(lock_context);
bool do_unmount;
rtems_filesystem_mt_entry_lock(lock_context);
rtems_chain_extract_unprotected(&loc->mt_entry_node);
do_unmount = rtems_filesystem_is_ready_for_unmount(loc->mt_entry);
rtems_filesystem_mt_entry_unlock(lock_context);
if (do_unmount) {
rtems_filesystem_do_unmount(loc->mt_entry);
}
}
void rtems_filesystem_do_unmount(
rtems_filesystem_mount_table_entry_t *mt_entry
)
{
rtems_filesystem_mt_lock();
rtems_chain_extract_unprotected(&mt_entry->mt_node);
rtems_filesystem_mt_unlock();
rtems_filesystem_global_location_release(mt_entry->mt_point_node);
(*mt_entry->mt_fs_root->location.ops->fsunmount_me_h)(mt_entry);
free(mt_entry);
}
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