incubator-nuttx/fs/fs.h

365 lines
13 KiB
C

/****************************************************************************
* fs/fs.h
*
* Copyright (C) 2007, 2009, 2012, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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_FS_H
#define _FS_FS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <dirent.h>
#include <nuttx/fs/fs.h>
#include <nuttx/compiler.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Inode i_flag values */
#define FSNODEFLAG_TYPE_MASK 0x00000007 /* Isolates type field */
#define FSNODEFLAG_TYPE_DRIVER 0x00000000 /* Character driver */
#define FSNODEFLAG_TYPE_BLOCK 0x00000001 /* Block driver */
#define FSNODEFLAG_TYPE_MOUNTPT 0x00000002 /* Mount point */
#define FSNODEFLAG_TYPE_SPECIAL 0x00000004 /* Special OS type */
#define FSNODEFLAG_TYPE_NAMEDSEM 0x00000004 /* Named semaphore */
#define FSNODEFLAG_TYPE_MQUEUE 0x00000005 /* Message Queue */
#define FSNODEFLAG_TYPE_SHM 0x00000006 /* Shared memory region */
#define FSNODEFLAG_DELETED 0x00000008 /* Unlinked */
#define INODE_IS_TYPE(i,t) \
(((i)->i_flags & FSNODEFLAG_TYPE_MASK) == (t))
#define INODE_IS_SPECIAL(i) \
(((i)->i_flags & FSNODEFLAG_TYPE_SPECIAL) != 0)
#define INODE_IS_DRIVER(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_DRIVER)
#define INODE_IS_BLOCK(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_BLOCK)
#define INODE_IS_MOUNTPT(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_MOUNTPT)
#define INODE_IS_NAMEDSEM(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_NAMEDSEM)
#define INODE_IS_MQUEUE(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_MQUEUE)
#define INODE_IS_SHM(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_SHM)
#define INODE_GET_TYPE(i) ((i)->i_flags & FSNODEFLAG_TYPE_MASK)
#define INODE_SET_TYPE(i,t) \
do \
{ \
(i)->i_flags = ((i)->i_flags & ~FSNODEFLAG_TYPE_MASK) | (t); \
} \
while (0)
#define INODE_SET_DRIVER(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_DRIVER)
#define INODE_SET_BLOCK(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_BLOCK)
#define INODE_SET_MOUNTPT(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_MOUNTPT)
#define INODE_SET_NAMEDSEM(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_NAMEDSEM)
#define INODE_SET_MQUEUE(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_MQUEUE)
#define INODE_SET_SHM(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_SHM)
/* Mountpoint fd_flags values */
#define DIRENTFLAGS_PSEUDONODE 1
#define DIRENT_SETPSEUDONODE(f) do (f) |= DIRENTFLAGS_PSEUDONODE; while (0)
#define DIRENT_ISPSEUDONODE(f) (((f) & DIRENTFLAGS_PSEUDONODE) != 0)
/****************************************************************************
* Public Types
****************************************************************************/
/* Callback used by foreach_inode to traverse all inodes in the pseudo-
* file system.
*/
typedef int (*foreach_inode_t)(FAR struct inode *node,
FAR char dirpath[PATH_MAX],
FAR void *arg);
/****************************************************************************
* Global Variables
****************************************************************************/
extern FAR struct inode *root_inode;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/* fs_inode.c ***************************************************************/
/****************************************************************************
* Name: inode_semtake
*
* Description:
* Get exclusive access to the in-memory inode tree (tree_sem).
*
****************************************************************************/
void inode_semtake(void);
/****************************************************************************
* Name: inode_semgive
*
* Description:
* Relinquish exclusive access to the in-memory inode tree (tree_sem).
*
****************************************************************************/
void inode_semgive(void);
/****************************************************************************
* Name: inode_search
*
* Description:
* Find the inode associated with 'path' returning the inode references
* and references to its companion nodes.
*
* Assumptions:
* The caller holds the tree_sem
*
****************************************************************************/
FAR struct inode *inode_search(FAR const char **path,
FAR struct inode **peer,
FAR struct inode **parent,
FAR const char **relpath);
/****************************************************************************
* Name: inode_free
*
* Description:
* Free resources used by an inode
*
****************************************************************************/
void inode_free(FAR struct inode *node);
/****************************************************************************
* Name: inode_nextname
*
* Description:
* Given a path with node names separated by '/', return the next node
* name.
*
****************************************************************************/
const char *inode_nextname(FAR const char *name);
/* fs_inodereserver.c *******************************************************/
/****************************************************************************
* Name: inode_reserve
*
* Description:
* Reserve an (initialized) inode the pseudo file system.
*
* NOTE: Caller must hold the inode semaphore
*
* Input parameters:
* path - The path to the inode to create
* inode - The location to return the inode pointer
*
* Returned Value:
* Zero on success (with the inode point in 'inode'); A negated errno
* value is returned on failure:
*
* EINVAL - 'path' is invalid for this operation
* EEXIST - An inode already exists at 'path'
* ENOMEM - Failed to allocate in-memory resources for the operation
*
****************************************************************************/
int inode_reserve(FAR const char *path, FAR struct inode **inode);
/* fs_inoderemove.c *********************************************************/
/****************************************************************************
* Name: inode_unlink
*
* Description:
* Given a path, remove a the node from the in-memory, inode tree that the
* path refers to. This is normally done in preparation to removing or
* moving an inode.
*
* Assumptions/Limitations:
* The caller must hold the inode semaphore
*
****************************************************************************/
FAR struct inode *inode_unlink(FAR const char *path);
/****************************************************************************
* Name: inode_remove
*
* Description:
* Given a path, remove a the node from the in-memory, inode tree that the
* path refers to and free all resources related to the inode. If the
* inode is in-use, then it will be unlinked, but will not be freed until
* the last reference to the inode is released.
*
* Assumptions/Limitations:
* The caller must hold the inode semaphore
*
****************************************************************************/
int inode_remove(FAR const char *path);
/* fs_inodefind.c ***********************************************************/
/****************************************************************************
* Name: inode_find
*
* Description:
* This is called from the open() logic to get a reference to the inode
* associated with a path.
*
****************************************************************************/
FAR struct inode *inode_find(FAR const char *path, const char **relpath);
/* fs_inodeaddref.c *********************************************************/
void inode_addref(FAR struct inode *inode);
/* fs_inoderelease.c ********************************************************/
void inode_release(FAR struct inode *inode);
/* fs_foreachinode.c ********************************************************/
/****************************************************************************
* Name: foreach_inode
*
* Description:
* Visit each inode in the pseudo-file system. The traversal is terminated
* when the callback 'handler' returns a non-zero value, or when all of
* the inodes have been visited.
*
* NOTE 1: Use with caution... The pseudo-file system is locked throughout
* the traversal.
* NOTE 2: The search algorithm is recursive and could, in principle, use
* an indeterminant amount of stack space. This will not usually be a
* real work issue.
*
****************************************************************************/
int foreach_inode(foreach_inode_t handler, FAR void *arg);
/* fs_files.c ***************************************************************/
/****************************************************************************
* Name: files_initialize
*
* Description:
* This is called from the FS initialization logic to configure the files.
*
****************************************************************************/
void weak_function files_initialize(void);
/****************************************************************************
* Name: files_allocate
*
* Description:
* Allocate a struct files instance and associate it with an inode instance.
* Returns the file descriptor == index into the files array.
*
****************************************************************************/
int files_allocate(FAR struct inode *inode, int oflags, off_t pos, int minfd);
/****************************************************************************
* Name: files_close
*
* Description:
* Close an inode (if open)
*
* Assumuptions:
* Caller holds the list semaphore because the file descriptor will be freed.
*
****************************************************************************/
int files_close(int fd);
/****************************************************************************
* Name: files_release
*
* Assumuptions:
* Similar to files_close(). Called only from open() logic on error
* conditions.
*
****************************************************************************/
void files_release(int fd);
/* fs_findblockdriver.c *****************************************************/
/****************************************************************************
* Name: find_blockdriver
*
* Description:
* Return the inode of the block driver specified by 'pathname'
*
* Inputs:
* pathname - the full path to the block driver to be located
* mountflags - if MS_RDONLY is not set, then driver must support write
* operations (see include/sys/mount.h)
* ppinode - address of the location to return the inode reference
*
* Return:
* Returns zero on success or a negated errno on failure:
*
* EINVAL - pathname or pinode is NULL
* ENOENT - No block driver of this name is registered
* ENOTBLK - The inode associated with the pathname is not a block driver
* EACCESS - The MS_RDONLY option was not set but this driver does not
* support write access
*
****************************************************************************/
int find_blockdriver(FAR const char *pathname, int mountflags,
FAR struct inode **ppinode);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* _FS_FS_H */