nuttx/include/nuttx/fs/loop.h
2015-11-25 17:52:47 -06:00

150 lines
5.2 KiB
C

/****************************************************************************
* include/nuttx/fs/loop.h
*
* Copyright (C) 2015 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 __INCLUDE_NUTTX_FS_LOOP_H
#define __INCLUDE_NUTTX_FS_LOOP_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/fs/ioctl.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_DEV_LOOP
/* Loop device IOCTL commands */
/* Command: LOOPIOC_SETUP
* Description: Setup the loop device
* Argument: A pointer to a read-only instance of struct losetup_s.
* Dependencies: The loop device must be enabled (CONFIG_DEV_LOOP=y)
*/
/* Command: LOOPIOC_TEARDOWN
* Description: Teardown a loop device previously setup vis LOOPIOC_SETUP
* Argument: A read-able pointer to the path of the device to be
* torn down
* Dependencies: The loop device must be enabled (CONFIG_DEV_LOOP=y)
*/
#define LOOPIOC_SETUP _LOOPIOC(0x0001)
#define LOOPIOC_TEARDOWN _LOOPIOC(0x0002)
#endif
/****************************************************************************
* Type Definitions
****************************************************************************/
#ifdef CONFIG_DEV_LOOP
/* This is the structure referred to in the argument to the LOOPIOC_SETUP
* IOCTL command.
*/
struct losetup_s
{
FAR const char *devname; /* The loop block device to be created */
FAR const char *filename; /* The file or character device to use */
uint16_t sectsize; /* The sector size to use with the block device */
off_t offset; /* An offset that may be applied to the device */
bool readonly; /* True: Read access will be supported only */
};
#endif
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __KERNEL__
/* These are internal OS interface and are not available to applications */
/****************************************************************************
* Name: loop_register
*
* Description:
* Register /dev/loop
*
****************************************************************************/
#ifdef CONFIG_DEV_LOOP
void loop_register(void);
#endif
/****************************************************************************
* Name: losetup
*
* Description:
* Setup the loop device so that it exports the file referenced by 'filename'
* as a block device.
*
****************************************************************************/
int losetup(FAR const char *devname, FAR const char *filename,
uint16_t sectsize, off_t offset, bool readonly);
/****************************************************************************
* Name: loteardown
*
* Description:
* Undo the setup performed by losetup
*
****************************************************************************/
int loteardown(FAR const char *devname);
#endif /* __KERNEL __ */
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_FS_LOOP_H */