[3b7c123] | 1 | /* |
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| 2 | * Copyright (c) 2012 embedded brains GmbH. All rights reserved. |
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| 3 | * |
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| 4 | * embedded brains GmbH |
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| 5 | * Obere Lagerstr. 30 |
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| 6 | * 82178 Puchheim |
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| 7 | * Germany |
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| 8 | * <rtems@embedded-brains.de> |
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| 9 | * |
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| 10 | * The license and distribution terms for this file may be |
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| 11 | * found in the file LICENSE in this distribution or at |
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| 12 | * http://www.rtems.com/license/LICENSE. |
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| 13 | */ |
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| 14 | |
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| 15 | #if HAVE_CONFIG_H |
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| 16 | #include "config.h" |
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| 17 | #endif |
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| 18 | |
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| 19 | #define __RTEMS_VIOLATE_KERNEL_VISIBILITY__ |
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| 20 | |
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| 21 | #include <stdlib.h> |
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| 22 | |
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| 23 | #include <rtems/libio_.h> |
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| 24 | #include <rtems/score/thread.h> |
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| 25 | |
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| 26 | static rtems_filesystem_global_location_t *deferred_released_global_locations; |
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| 27 | |
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| 28 | rtems_filesystem_location_info_t *rtems_filesystem_location_copy( |
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| 29 | rtems_filesystem_location_info_t *dst, |
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| 30 | const rtems_filesystem_location_info_t *src |
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| 31 | ) |
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| 32 | { |
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| 33 | dst->node_access = src->node_access; |
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| 34 | dst->node_access_2 = src->node_access_2; |
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| 35 | dst->handlers = src->handlers; |
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| 36 | dst->mt_entry = src->mt_entry; |
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| 37 | rtems_filesystem_location_add_to_mt_entry(dst); |
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| 38 | |
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| 39 | return dst; |
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| 40 | } |
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| 41 | |
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| 42 | void rtems_filesystem_location_detach( |
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| 43 | rtems_filesystem_location_info_t *detach |
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| 44 | ) |
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| 45 | { |
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| 46 | rtems_filesystem_location_free(detach); |
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| 47 | rtems_filesystem_location_initialize_to_null(detach); |
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| 48 | } |
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| 49 | |
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| 50 | void rtems_filesystem_location_copy_and_detach( |
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| 51 | rtems_filesystem_location_info_t *copy, |
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| 52 | rtems_filesystem_location_info_t *detach |
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| 53 | ) |
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| 54 | { |
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| 55 | rtems_filesystem_location_copy(copy, detach); |
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| 56 | rtems_filesystem_location_remove_from_mt_entry(detach); |
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| 57 | rtems_filesystem_location_initialize_to_null(detach); |
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| 58 | } |
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| 59 | |
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| 60 | rtems_filesystem_global_location_t *rtems_filesystem_location_transform_to_global( |
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| 61 | rtems_filesystem_location_info_t *loc |
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| 62 | ) |
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| 63 | { |
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| 64 | rtems_filesystem_global_location_t *global_loc = malloc(sizeof(*global_loc)); |
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| 65 | |
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| 66 | if (global_loc != NULL) { |
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| 67 | global_loc->reference_count = 1; |
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| 68 | global_loc->deferred_released_next = NULL; |
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| 69 | global_loc->deferred_released_count = 0; |
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| 70 | rtems_filesystem_location_copy(&global_loc->location, loc); |
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| 71 | rtems_filesystem_location_remove_from_mt_entry(loc); |
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| 72 | } else { |
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| 73 | rtems_filesystem_location_free(loc); |
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| 74 | global_loc = rtems_filesystem_global_location_obtain_null(); |
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| 75 | errno = ENOMEM; |
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| 76 | } |
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| 77 | |
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| 78 | return global_loc; |
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| 79 | } |
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| 80 | |
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| 81 | void rtems_filesystem_global_location_assign( |
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| 82 | rtems_filesystem_global_location_t **lhs_global_loc_ptr, |
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| 83 | rtems_filesystem_global_location_t *rhs_global_loc |
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| 84 | ) |
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| 85 | { |
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| 86 | rtems_filesystem_mt_entry_declare_lock_context(lock_context); |
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| 87 | rtems_filesystem_global_location_t *lhs_global_loc; |
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| 88 | |
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| 89 | rtems_filesystem_mt_entry_lock(lock_context); |
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| 90 | lhs_global_loc = *lhs_global_loc_ptr; |
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| 91 | *lhs_global_loc_ptr = rhs_global_loc; |
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| 92 | rtems_filesystem_mt_entry_unlock(lock_context); |
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| 93 | |
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| 94 | rtems_filesystem_global_location_release(lhs_global_loc); |
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| 95 | } |
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| 96 | |
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| 97 | static void release_with_count( |
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| 98 | rtems_filesystem_global_location_t *global_loc, |
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| 99 | int count |
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| 100 | ) |
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| 101 | { |
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| 102 | rtems_filesystem_mount_table_entry_t *mt_entry = |
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| 103 | global_loc->location.mt_entry; |
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| 104 | rtems_filesystem_mt_entry_declare_lock_context(lock_context); |
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| 105 | bool do_free; |
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| 106 | bool do_unmount; |
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| 107 | |
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| 108 | rtems_filesystem_mt_entry_lock(lock_context); |
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| 109 | global_loc->reference_count -= count; |
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| 110 | do_free = global_loc->reference_count == 0; |
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| 111 | do_unmount = rtems_filesystem_is_ready_for_unmount(mt_entry); |
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| 112 | rtems_filesystem_mt_entry_unlock(lock_context); |
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| 113 | |
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| 114 | if (do_free) { |
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| 115 | rtems_filesystem_location_free(&global_loc->location); |
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| 116 | free(global_loc); |
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| 117 | } |
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| 118 | |
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| 119 | if (do_unmount) { |
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| 120 | rtems_filesystem_do_unmount(mt_entry); |
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| 121 | } |
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| 122 | } |
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| 123 | |
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| 124 | static void deferred_release(void) |
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| 125 | { |
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| 126 | rtems_filesystem_global_location_t *current = NULL; |
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| 127 | |
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| 128 | do { |
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| 129 | int count = 0; |
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| 130 | |
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| 131 | _Thread_Disable_dispatch(); |
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| 132 | current = deferred_released_global_locations; |
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| 133 | if (current != NULL) { |
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| 134 | deferred_released_global_locations = current->deferred_released_next; |
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| 135 | count = current->deferred_released_count; |
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| 136 | current->deferred_released_next = NULL; |
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| 137 | current->deferred_released_count = 0; |
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| 138 | } |
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| 139 | _Thread_Enable_dispatch(); |
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| 140 | |
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| 141 | if (current != NULL) { |
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| 142 | release_with_count(current, count); |
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| 143 | } |
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| 144 | } while (current != NULL); |
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| 145 | } |
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| 146 | |
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| 147 | rtems_filesystem_global_location_t *rtems_filesystem_global_location_obtain( |
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| 148 | rtems_filesystem_global_location_t *const *global_loc_ptr |
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| 149 | ) |
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| 150 | { |
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| 151 | rtems_filesystem_mt_entry_declare_lock_context(lock_context); |
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| 152 | rtems_filesystem_global_location_t *global_loc; |
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| 153 | |
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| 154 | if (deferred_released_global_locations != NULL) { |
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| 155 | deferred_release(); |
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| 156 | } |
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| 157 | |
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| 158 | rtems_filesystem_mt_entry_lock(lock_context); |
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| 159 | global_loc = *global_loc_ptr; |
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| 160 | if (global_loc == NULL || !global_loc->location.mt_entry->mounted) { |
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| 161 | global_loc = &rtems_filesystem_global_location_null; |
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| 162 | errno = ENXIO; |
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| 163 | } |
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| 164 | ++global_loc->reference_count; |
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| 165 | rtems_filesystem_mt_entry_unlock(lock_context); |
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| 166 | |
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| 167 | return global_loc; |
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| 168 | } |
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| 169 | |
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| 170 | void rtems_filesystem_global_location_release( |
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| 171 | rtems_filesystem_global_location_t *global_loc |
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| 172 | ) |
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| 173 | { |
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| 174 | if (!_Thread_Dispatch_in_critical_section()) { |
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| 175 | release_with_count(global_loc, 1); |
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| 176 | } else { |
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| 177 | if (global_loc->deferred_released_count == 0) { |
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| 178 | rtems_filesystem_global_location_t *head = |
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| 179 | deferred_released_global_locations; |
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| 180 | |
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| 181 | global_loc->deferred_released_count = 1; |
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| 182 | global_loc->deferred_released_next = head; |
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| 183 | deferred_released_global_locations = global_loc; |
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| 184 | } else { |
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| 185 | ++global_loc->deferred_released_count; |
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| 186 | } |
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| 187 | } |
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| 188 | } |
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| 189 | |
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| 190 | void rtems_filesystem_location_remove_from_mt_entry( |
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| 191 | rtems_filesystem_location_info_t *loc |
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| 192 | ) |
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| 193 | { |
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| 194 | rtems_filesystem_mt_entry_declare_lock_context(lock_context); |
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| 195 | bool do_unmount; |
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| 196 | |
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| 197 | rtems_filesystem_mt_entry_lock(lock_context); |
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| 198 | rtems_chain_extract_unprotected(&loc->mt_entry_node); |
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| 199 | do_unmount = rtems_filesystem_is_ready_for_unmount(loc->mt_entry); |
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| 200 | rtems_filesystem_mt_entry_unlock(lock_context); |
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| 201 | |
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| 202 | if (do_unmount) { |
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| 203 | rtems_filesystem_do_unmount(loc->mt_entry); |
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| 204 | } |
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| 205 | } |
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| 206 | |
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| 207 | void rtems_filesystem_do_unmount( |
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| 208 | rtems_filesystem_mount_table_entry_t *mt_entry |
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| 209 | ) |
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| 210 | { |
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| 211 | rtems_filesystem_mt_lock(); |
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| 212 | rtems_chain_extract_unprotected(&mt_entry->mt_node); |
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| 213 | rtems_filesystem_mt_unlock(); |
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| 214 | rtems_filesystem_global_location_release(mt_entry->mt_point_node); |
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[da154e14] | 215 | (*mt_entry->ops->fsunmount_me_h)(mt_entry); |
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[847ad44] | 216 | |
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| 217 | if (mt_entry->unmount_task != 0) { |
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| 218 | rtems_status_code sc = |
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| 219 | rtems_event_send(mt_entry->unmount_task, RTEMS_FILESYSTEM_UNMOUNT_EVENT); |
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| 220 | if (sc != RTEMS_SUCCESSFUL) { |
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| 221 | rtems_fatal_error_occurred(0xdeadbeef); |
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| 222 | } |
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| 223 | } |
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| 224 | |
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[3b7c123] | 225 | free(mt_entry); |
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| 226 | } |
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