/**************************************************************************** * fs/tmpfs/fs_tmpfs.h * * Copyright (C) 2015 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * 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. * ****************************************************************************/ #ifndef __FS_TMPFS_FS_TMPFS_H #define __FS_TMPFS_FS_TMPFS_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Indicates that there is no holder of the re-entrant semaphore */ #define TMPFS_NO_HOLDER -1 /* Bit definitions for file object flags */ #define TFO_FLAG_UNLINKED (1 << 0) /* Bit 0: File is unlinked */ /**************************************************************************** * Public Types ****************************************************************************/ /* TMPFS memory object types */ enum tmpfs_objtype_e { TMPFS_DIRECTORY = 0, /* Directory */ TMPFS_REGULAR /* Regular file */ }; /* Values returned by tmpfs_foreach() */ enum tmpfs_foreach_e { TMPFS_CONTINUE = 0, /* Continue enumeration */ TMPFS_HALT, /* Stop enumeration */ TMPFS_DELETED, /* Object and directory entry deleted */ TMPFS_UNLINKED /* Only the directory entry was deleted */ }; /* Re-entrant semaphore */ struct tmpfs_sem_s { sem_t ts_sem; /* The actual semaphore */ pid_t ts_holder; /* Current older (-1 if not held) */ uint16_t ts_count; /* Number of counts held */ }; /* The form of one directory entry */ struct tmpfs_dirent_s { FAR struct tmpfs_object_s *tde_object; FAR char *tde_name; }; /* The generic form of a TMPFS memory object */ struct tmpfs_object_s { FAR struct tmpfs_dirent_s *to_dirent; struct tmpfs_sem_s to_exclsem; size_t to_alloc; /* Allocated size of the memory object */ uint8_t to_type; /* See enum tmpfs_objtype_e */ uint8_t to_refs; /* Reference count */ }; /* The form of a directory memory object */ struct tmpfs_directory_s { /* First fields must match common TMPFS object layout */ FAR struct tmpfs_dirent_s *tdo_dirent; struct tmpfs_sem_s tdo_exclsem; size_t tdo_alloc; /* Allocated size of the directory object */ uint8_t tdo_type; /* See enum tmpfs_objtype_e */ uint8_t tdo_refs; /* Reference count */ /* Remaining fields are unique to a directory object */ uint16_t tdo_nentries; /* Number of directory entries */ struct tmpfs_dirent_s tdo_entry[1]; }; #define SIZEOF_TMPFS_DIRECTORY(n) \ (sizeof(struct tmpfs_directory_s) + ((n) - 1) * sizeof(struct tmpfs_dirent_s)) /* The form of a regular file memory object * * NOTE that in this very simplified implementation, there is no per-open * state. The file memory object also serves as the open file object, * saving an allocation. This has the negative side effect that no per- * open state can be retained (such as open flags). */ struct tmpfs_file_s { /* First fields must match common TMPFS object layout */ FAR struct tmpfs_dirent_s *tfo_dirent; struct tmpfs_sem_s tfo_exclsem; size_t tfo_alloc; /* Allocated size of the file object */ uint8_t tfo_type; /* See enum tmpfs_objtype_e */ uint8_t tfo_refs; /* Reference count */ /* Remaining fields are unique to a directory object */ uint8_t tfo_flags; /* See TFO_FLAG_* definitions */ size_t tfo_size; /* Valid file size */ uint8_t tfo_data[1]; /* File data starts here */ }; #define SIZEOF_TMPFS_FILE(n) (sizeof(struct tmpfs_file_s) + (n) - 1) /* This structure represents one instance of a TMPFS file system */ struct tmpfs_s { /* The root directory */ FAR struct tmpfs_dirent_s tfs_root; struct tmpfs_sem_s tfs_exclsem; }; /* This is the type used the tmpfs_statfs_callout to accumulate memory * usage */ struct tmpfs_statfs_s { size_t tsf_alloc; /* Total memory allocated */ size_t tsf_inuse; /* Total memory in use */ off_t tsf_files; /* Total file nodes in the file system */ off_t tsf_ffree; /* Free directory nodes in the file system */ }; /* This is the type of the for tmpfs_foreach callback */ typedef int (*tmpfs_foreach_t)(FAR struct tmpfs_directory_s *tdo, unsigned int index, FAR void *arg); /**************************************************************************** * Public Data ****************************************************************************/ #undef EXTERN #if defined(__cplusplus) #define EXTERN extern "C" extern "C" { #else #define EXTERN extern #endif EXTERN const struct mountpt_operations tmpfs_operations; /**************************************************************************** * Public Function Prototypes ****************************************************************************/ #undef EXTERN #if defined(__cplusplus) } #endif #endif /* __FS_TMPFS_FS_TMPFS_H */