incubator-nuttx/include/nuttx/fs/loop.h

137 lines
4.4 KiB
C

/****************************************************************************
* include/nuttx/fs/loop.h
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#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 */