The C and C++ Include Header Files

/usr/include/linux/loop.h


$ cat -n /usr/include/linux/loop.h

     1	/* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
     2	/*
     3	 * Copyright 1993 by Theodore Ts'o.
     4	 */
     5	#ifndef _LINUX_LOOP_H
     6	#define _LINUX_LOOP_H
     7	
     8	
     9	#define LO_NAME_SIZE	64
    10	#define LO_KEY_SIZE	32
    11	
    12	
    13	/*
    14	 * Loop flags
    15	 */
    16	enum {
    17		LO_FLAGS_READ_ONLY	= 1,
    18		LO_FLAGS_AUTOCLEAR	= 4,
    19		LO_FLAGS_PARTSCAN	= 8,
    20		LO_FLAGS_DIRECT_IO	= 16,
    21	};
    22	
    23	/* LO_FLAGS that can be set using LOOP_SET_STATUS(64) */
    24	#define LOOP_SET_STATUS_SETTABLE_FLAGS (LO_FLAGS_AUTOCLEAR | LO_FLAGS_PARTSCAN)
    25	
    26	/* LO_FLAGS that can be cleared using LOOP_SET_STATUS(64) */
    27	#define LOOP_SET_STATUS_CLEARABLE_FLAGS (LO_FLAGS_AUTOCLEAR)
    28	
    29	/* LO_FLAGS that can be set using LOOP_CONFIGURE */
    30	#define LOOP_CONFIGURE_SETTABLE_FLAGS (LO_FLAGS_READ_ONLY | LO_FLAGS_AUTOCLEAR \
    31					       | LO_FLAGS_PARTSCAN | LO_FLAGS_DIRECT_IO)
    32	
    33	#include <asm/posix_types.h>	/* for __kernel_old_dev_t */
    34	#include <linux/types.h>	/* for __u64 */
    35	
    36	/* Backwards compatibility version */
    37	struct loop_info {
    38		int		   lo_number;		/* ioctl r/o */
    39		__kernel_old_dev_t lo_device; 		/* ioctl r/o */
    40		unsigned long	   lo_inode; 		/* ioctl r/o */
    41		__kernel_old_dev_t lo_rdevice; 		/* ioctl r/o */
    42		int		   lo_offset;
    43		int		   lo_encrypt_type;		/* obsolete, ignored */
    44		int		   lo_encrypt_key_size; 	/* ioctl w/o */
    45		int		   lo_flags;
    46		char		   lo_name[LO_NAME_SIZE];
    47		unsigned char	   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
    48		unsigned long	   lo_init[2];
    49		char		   reserved[4];
    50	};
    51	
    52	struct loop_info64 {
    53		__u64		   lo_device;			/* ioctl r/o */
    54		__u64		   lo_inode;			/* ioctl r/o */
    55		__u64		   lo_rdevice;			/* ioctl r/o */
    56		__u64		   lo_offset;
    57		__u64		   lo_sizelimit;/* bytes, 0 == max available */
    58		__u32		   lo_number;			/* ioctl r/o */
    59		__u32		   lo_encrypt_type;		/* obsolete, ignored */
    60		__u32		   lo_encrypt_key_size;		/* ioctl w/o */
    61		__u32		   lo_flags;
    62		__u8		   lo_file_name[LO_NAME_SIZE];
    63		__u8		   lo_crypt_name[LO_NAME_SIZE];
    64		__u8		   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
    65		__u64		   lo_init[2];
    66	};
    67	
    68	/**
    69	 * struct loop_config - Complete configuration for a loop device.
    70	 * @fd: fd of the file to be used as a backing file for the loop device.
    71	 * @block_size: block size to use; ignored if 0.
    72	 * @info: struct loop_info64 to configure the loop device with.
    73	 *
    74	 * This structure is used with the LOOP_CONFIGURE ioctl, and can be used to
    75	 * atomically setup and configure all loop device parameters at once.
    76	 */
    77	struct loop_config {
    78		__u32			fd;
    79		__u32                   block_size;
    80		struct loop_info64	info;
    81		__u64			__reserved[8];
    82	};
    83	
    84	/*
    85	 * Loop filter types
    86	 */
    87	
    88	#define LO_CRYPT_NONE		0
    89	#define LO_CRYPT_XOR		1
    90	#define LO_CRYPT_DES		2
    91	#define LO_CRYPT_FISH2		3    /* Twofish encryption */
    92	#define LO_CRYPT_BLOW		4
    93	#define LO_CRYPT_CAST128	5
    94	#define LO_CRYPT_IDEA		6
    95	#define LO_CRYPT_DUMMY		9
    96	#define LO_CRYPT_SKIPJACK	10
    97	#define LO_CRYPT_CRYPTOAPI	18
    98	#define MAX_LO_CRYPT		20
    99	
   100	/*
   101	 * IOCTL commands --- we will commandeer 0x4C ('L')
   102	 */
   103	
   104	#define LOOP_SET_FD		0x4C00
   105	#define LOOP_CLR_FD		0x4C01
   106	#define LOOP_SET_STATUS		0x4C02
   107	#define LOOP_GET_STATUS		0x4C03
   108	#define LOOP_SET_STATUS64	0x4C04
   109	#define LOOP_GET_STATUS64	0x4C05
   110	#define LOOP_CHANGE_FD		0x4C06
   111	#define LOOP_SET_CAPACITY	0x4C07
   112	#define LOOP_SET_DIRECT_IO	0x4C08
   113	#define LOOP_SET_BLOCK_SIZE	0x4C09
   114	#define LOOP_CONFIGURE		0x4C0A
   115	
   116	/* /dev/loop-control interface */
   117	#define LOOP_CTL_ADD		0x4C80
   118	#define LOOP_CTL_REMOVE		0x4C81
   119	#define LOOP_CTL_GET_FREE	0x4C82
   120	#endif /* _LINUX_LOOP_H */