212 lines
6.6 KiB
C
212 lines
6.6 KiB
C
/****************************************************************************
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* fs/tmpfs/fs_tmpfs.h
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*
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* Copyright (C) 2015 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#ifndef __FS_TMPFS_FS_TMPFS_H
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#define __FS_TMPFS_FS_TMPFS_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <stdint.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/semaphore.h>
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Indicates that there is no holder of the re-entrant semaphore */
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#define TMPFS_NO_HOLDER -1
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/* Bit definitions for file object flags */
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#define TFO_FLAG_UNLINKED (1 << 0) /* Bit 0: File is unlinked */
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/****************************************************************************
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* Public Types
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****************************************************************************/
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/* TMPFS memory object types */
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enum tmpfs_objtype_e
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{
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TMPFS_DIRECTORY = 0, /* Directory */
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TMPFS_REGULAR /* Regular file */
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};
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/* Values returned by tmpfs_foreach() */
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enum tmpfs_foreach_e
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{
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TMPFS_CONTINUE = 0, /* Continue enumeration */
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TMPFS_HALT, /* Stop enumeration */
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TMPFS_DELETED, /* Object and directory entry deleted */
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TMPFS_UNLINKED /* Only the directory entry was deleted */
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};
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/* Re-entrant semaphore */
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struct tmpfs_sem_s
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{
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sem_t ts_sem; /* The actual semaphore */
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pid_t ts_holder; /* Current older (-1 if not held) */
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uint16_t ts_count; /* Number of counts held */
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};
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/* The form of one directory entry */
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struct tmpfs_dirent_s
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{
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FAR struct tmpfs_object_s *tde_object;
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FAR char *tde_name;
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};
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/* The generic form of a TMPFS memory object */
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struct tmpfs_object_s
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{
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FAR struct tmpfs_dirent_s *to_dirent;
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struct tmpfs_sem_s to_exclsem;
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size_t to_alloc; /* Allocated size of the memory object */
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uint8_t to_type; /* See enum tmpfs_objtype_e */
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uint8_t to_refs; /* Reference count */
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};
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/* The form of a directory memory object */
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struct tmpfs_directory_s
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{
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/* First fields must match common TMPFS object layout */
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FAR struct tmpfs_dirent_s *tdo_dirent;
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struct tmpfs_sem_s tdo_exclsem;
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size_t tdo_alloc; /* Allocated size of the directory object */
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uint8_t tdo_type; /* See enum tmpfs_objtype_e */
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uint8_t tdo_refs; /* Reference count */
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/* Remaining fields are unique to a directory object */
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uint16_t tdo_nentries; /* Number of directory entries */
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struct tmpfs_dirent_s tdo_entry[1];
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};
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#define SIZEOF_TMPFS_DIRECTORY(n) \
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(sizeof(struct tmpfs_directory_s) + ((n) - 1) * sizeof(struct tmpfs_dirent_s))
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/* The form of a regular file memory object
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*
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* NOTE that in this very simplified implementation, there is no per-open
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* state. The file memory object also serves as the open file object,
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* saving an allocation. This has the negative side effect that no per-
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* open state can be retained (such as open flags).
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*/
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struct tmpfs_file_s
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{
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/* First fields must match common TMPFS object layout */
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FAR struct tmpfs_dirent_s *tfo_dirent;
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struct tmpfs_sem_s tfo_exclsem;
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size_t tfo_alloc; /* Allocated size of the file object */
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uint8_t tfo_type; /* See enum tmpfs_objtype_e */
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uint8_t tfo_refs; /* Reference count */
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/* Remaining fields are unique to a directory object */
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uint8_t tfo_flags; /* See TFO_FLAG_* definitions */
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size_t tfo_size; /* Valid file size */
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uint8_t tfo_data[1]; /* File data starts here */
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};
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#define SIZEOF_TMPFS_FILE(n) (sizeof(struct tmpfs_file_s) + (n) - 1)
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/* This structure represents one instance of a TMPFS file system */
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struct tmpfs_s
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{
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/* The root directory */
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FAR struct tmpfs_dirent_s tfs_root;
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struct tmpfs_sem_s tfs_exclsem;
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};
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/* This is the type used the tmpfs_statfs_callout to accumulate memory usage */
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struct tmpfs_statfs_s
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{
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size_t tsf_alloc; /* Total memory allocated */
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size_t tsf_inuse; /* Total memory in use */
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off_t tsf_files; /* Total file nodes in the file system */
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off_t tsf_ffree; /* Free directory nodes in the file system */
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};
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/* This is the type of the for tmpfs_foreach callback */
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typedef int (*tmpfs_foreach_t)(FAR struct tmpfs_directory_s *tdo,
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unsigned int index, FAR void *arg);
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/****************************************************************************
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* Public Data
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****************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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#define EXTERN extern "C"
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extern "C"
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{
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#else
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#define EXTERN extern
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#endif
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EXTERN const struct mountpt_operations tmpfs_operations;
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/****************************************************************************
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* Public Function Prototypes
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****************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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}
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#endif
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#endif /* __FS_TMPFS_FS_TMPFS_H */
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