diff options
Diffstat (limited to 'cpukit/include/rtems/fs.h')
| -rw-r--r-- | cpukit/include/rtems/fs.h | 59 |
1 files changed, 50 insertions, 9 deletions
diff --git a/cpukit/include/rtems/fs.h b/cpukit/include/rtems/fs.h index 84b18370b5..bf5026f645 100644 --- a/cpukit/include/rtems/fs.h +++ b/cpukit/include/rtems/fs.h @@ -8,6 +8,9 @@ * COPYRIGHT (c) 1989-2011. * On-Line Applications Research Corporation (OAR). * + * Modifications to support reference counting in the file system are + * Copyright (c) 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.com/license/LICENSE. @@ -18,6 +21,8 @@ #ifndef _RTEMS_FS_H #define _RTEMS_FS_H +#include <rtems/chain.h> + #ifdef __cplusplus extern "C" { #endif @@ -31,9 +36,6 @@ extern "C" { /* FIXME: shouldn't this better not be here? */ typedef struct rtems_libio_tt rtems_libio_t; -typedef struct rtems_filesystem_location_info_tt - rtems_filesystem_location_info_t; - struct rtems_filesystem_mount_table_entry_tt; typedef struct rtems_filesystem_mount_table_entry_tt rtems_filesystem_mount_table_entry_t; @@ -43,18 +45,57 @@ typedef struct _rtems_filesystem_file_handlers_r typedef struct _rtems_filesystem_operations_table rtems_filesystem_operations_table; -/* - * Structure used to determine a location/filesystem in the tree. +/** + * @brief File system location. + * + * @ingroup LibIO */ - -struct rtems_filesystem_location_info_tt -{ +typedef struct rtems_filesystem_location_info_tt { + rtems_chain_node mt_entry_node; void *node_access; void *node_access_2; const rtems_filesystem_file_handlers_r *handlers; const rtems_filesystem_operations_table *ops; rtems_filesystem_mount_table_entry_t *mt_entry; -}; +} rtems_filesystem_location_info_t; + +/** + * @brief Global file system location. + * + * @ingroup LibIO + * + * The global file system locations are used for + * - the mount point location in the mount table entry, + * - the file system root location in the mount table entry, + * - the root directory location in the user environment, and + * - the current directory location in the user environment. + * + * During the path evaluation global start locations are obtained to ensure + * that the current file system will be not unmounted in the meantime. + * + * To support a release within critical sections of the operating system a + * deferred release is supported. This is similar to malloc() and free(). + * + * @see rtems_filesystem_global_location_obtain() and + * rtems_filesystem_global_location_release(). + */ +typedef struct rtems_filesystem_global_location_t { + rtems_filesystem_location_info_t location; + int reference_count; + + /** + * A release within a critical section of the operating system will add this + * location to a list of deferred released locations. This list is processed + * in the next rtems_filesystem_global_location_obtain() in FIFO order. + */ + struct rtems_filesystem_global_location_t *deferred_released_next; + + /** + * A release within a critical section can happen multiple times. This field + * counts the deferred releases. + */ + int deferred_released_count; +} rtems_filesystem_global_location_t; /* * Return the mount table entry for a path location. |