ioctl.h

/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS_IOCTL_H__
#define __BTRFS_IOCTL_H__

#ifdef __cplusplus
extern "C" {
#endif

#include <asm/types.h>
#include <linux/ioctl.h>
#include <stddef.h>

#ifndef __user
#define __user
#endif

/* We don't want to include entire kerncompat.h */
#ifndef BUILD_ASSERT
#define BUILD_ASSERT(x)
#endif

#define BTRFS_IOCTL_MAGIC 0x94
#define BTRFS_VOL_NAME_MAX 255

/* this should be 4k */
#define BTRFS_PATH_NAME_MAX 4087
struct btrfs_ioctl_vol_args {
	__s64 fd;
	char name[BTRFS_PATH_NAME_MAX + 1];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args) == 4096);

#define BTRFS_DEVICE_PATH_NAME_MAX 1024

/*
 * Obsolete since 5.15, functionality removed in kernel 5.7:
 * BTRFS_SUBVOL_CREATE_ASYNC		(1ULL << 0)
 */
#define BTRFS_SUBVOL_RDONLY		(1ULL << 1)
#define BTRFS_SUBVOL_QGROUP_INHERIT	(1ULL << 2)
#define BTRFS_DEVICE_SPEC_BY_ID		(1ULL << 3)
#define BTRFS_SUBVOL_SPEC_BY_ID		(1ULL << 4)

#define BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED		\
			(BTRFS_SUBVOL_RDONLY |		\
			BTRFS_SUBVOL_QGROUP_INHERIT |	\
			BTRFS_DEVICE_SPEC_BY_ID |	\
			BTRFS_SUBVOL_SPEC_BY_ID)

#define BTRFS_FSID_SIZE 16
#define BTRFS_UUID_SIZE 16

#define BTRFS_QGROUP_INHERIT_SET_LIMITS	(1ULL << 0)

struct btrfs_qgroup_limit {
	__u64	flags;
	__u64	max_referenced;
	__u64	max_exclusive;
	__u64	rsv_referenced;
	__u64	rsv_exclusive;
};
BUILD_ASSERT(sizeof(struct btrfs_qgroup_limit) == 40);

struct btrfs_qgroup_inherit {
	__u64	flags;
	__u64	num_qgroups;
	__u64	num_ref_copies;
	__u64	num_excl_copies;
	struct btrfs_qgroup_limit lim;
	__u64	qgroups[0];
};
BUILD_ASSERT(sizeof(struct btrfs_qgroup_inherit) == 72);

struct btrfs_ioctl_qgroup_limit_args {
	__u64	qgroupid;
	struct btrfs_qgroup_limit lim;
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_qgroup_limit_args) == 48);

#define BTRFS_SUBVOL_NAME_MAX 4039
struct btrfs_ioctl_vol_args_v2 {
	__s64 fd;
	__u64 transid;
	__u64 flags;
	union {
		struct {
			__u64 size;
			struct btrfs_qgroup_inherit __user *qgroup_inherit;
		};
		__u64 unused[4];
	};
	union {
		char name[BTRFS_SUBVOL_NAME_MAX + 1];
		__u64 devid;
		__u64 subvolid;
	};
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_vol_args_v2) == 4096);

/*
 * structure to report errors and progress to userspace, either as a
 * result of a finished scrub, a canceled scrub or a progress inquiry
 */
struct btrfs_scrub_progress {
	__u64 data_extents_scrubbed;	/* # of data extents scrubbed */
	__u64 tree_extents_scrubbed;	/* # of tree extents scrubbed */
	__u64 data_bytes_scrubbed;	/* # of data bytes scrubbed */
	__u64 tree_bytes_scrubbed;	/* # of tree bytes scrubbed */
	__u64 read_errors;		/* # of read errors encountered (EIO) */
	__u64 csum_errors;		/* # of failed csum checks */
	__u64 verify_errors;		/* # of occurrences, where the metadata
					 * of a tree block did not match the
					 * expected values, like generation or
					 * logical */
	__u64 no_csum;			/* # of 4k data block for which no csum
					 * is present, probably the result of
					 * data written with nodatasum */
	__u64 csum_discards;		/* # of csum for which no data was found
					 * in the extent tree. */
	__u64 super_errors;		/* # of bad super blocks encountered */
	__u64 malloc_errors;		/* # of internal kmalloc errors. These
					 * will likely cause an incomplete
					 * scrub */
	__u64 uncorrectable_errors;	/* # of errors where either no intact
					 * copy was found or the writeback
					 * failed */
	__u64 corrected_errors;		/* # of errors corrected */
	__u64 last_physical;		/* last physical address scrubbed. In
					 * case a scrub was aborted, this can
					 * be used to restart the scrub */
	__u64 unverified_errors;	/* # of occurrences where a read for a
					 * full (64k) bio failed, but the re-
					 * check succeeded for each 4k piece.
					 * Intermittent error. */
};

#define BTRFS_SCRUB_READONLY	1
struct btrfs_ioctl_scrub_args {
	__u64 devid;				/* in */
	__u64 start;				/* in */
	__u64 end;				/* in */
	__u64 flags;				/* in */
	struct btrfs_scrub_progress progress;	/* out */
	/* pad to 1k */
	__u64 unused[(1024-32-sizeof(struct btrfs_scrub_progress))/8];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_scrub_args) == 1024);

#define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS	0
#define BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID	1
struct btrfs_ioctl_dev_replace_start_params {
	__u64 srcdevid;	/* in, if 0, use srcdev_name instead */
	__u64 cont_reading_from_srcdev_mode;	/* in, see #define
						 * above */
	__u8 srcdev_name[BTRFS_DEVICE_PATH_NAME_MAX + 1];	/* in */
	__u8 tgtdev_name[BTRFS_DEVICE_PATH_NAME_MAX + 1];	/* in */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_dev_replace_start_params) == 2072);

#define BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED	0
#define BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED		1
#define BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED		2
#define BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED		3
#define BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED		4
struct btrfs_ioctl_dev_replace_status_params {
	__u64 replace_state;	/* out, see #define above */
	__u64 progress_1000;	/* out, 0 <= x <= 1000 */
	__u64 time_started;	/* out, seconds since 1-Jan-1970 */
	__u64 time_stopped;	/* out, seconds since 1-Jan-1970 */
	__u64 num_write_errors;	/* out */
	__u64 num_uncorrectable_read_errors;	/* out */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_dev_replace_status_params) == 48);

#define BTRFS_IOCTL_DEV_REPLACE_CMD_START			0
#define BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS			1
#define BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL			2
#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_RESULT		-1
#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR			0
#define BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED		1
#define BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED		2
#define BTRFS_IOCTL_DEV_REPLACE_RESULT_SCRUB_INPROGRESS		3
struct btrfs_ioctl_dev_replace_args {
	__u64 cmd;	/* in */
	__u64 result;	/* out */

	union {
		struct btrfs_ioctl_dev_replace_start_params start;
		struct btrfs_ioctl_dev_replace_status_params status;
	};	/* in/out */

	__u64 spare[64];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_dev_replace_args) == 2600);

struct btrfs_ioctl_dev_info_args {
	__u64 devid;				/* in/out */
	__u8 uuid[BTRFS_UUID_SIZE];		/* in/out */
	__u64 bytes_used;			/* out */
	__u64 total_bytes;			/* out */
	__u64 unused[379];			/* pad to 4k */
	__u8 path[BTRFS_DEVICE_PATH_NAME_MAX];	/* out */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_dev_info_args) == 4096);

struct btrfs_ioctl_fs_info_args {
	__u64 max_id;				/* out */
	__u64 num_devices;			/* out */
	__u8 fsid[BTRFS_FSID_SIZE];		/* out */
	__u32 nodesize;				/* out */
	__u32 sectorsize;			/* out */
	__u32 clone_alignment;			/* out */
	__u32 reserved32;
	__u64 reserved[122];			/* pad to 1k */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_fs_info_args) == 1024);

struct btrfs_ioctl_feature_flags {
	__u64 compat_flags;
	__u64 compat_ro_flags;
	__u64 incompat_flags;
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_feature_flags) == 24);

/* balance control ioctl modes */
#define BTRFS_BALANCE_CTL_PAUSE		1
#define BTRFS_BALANCE_CTL_CANCEL	2
#define BTRFS_BALANCE_CTL_RESUME	3

/*
 * this is packed, because it should be exactly the same as its disk
 * byte order counterpart (struct btrfs_disk_balance_args)
 */
struct btrfs_balance_args {
	__u64 profiles;

	/*
	 * usage filter
	 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
	 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
	 */
	union {
		__u64 usage;
		struct {
			__u32 usage_min;
			__u32 usage_max;
		};
	};

	__u64 devid;
	__u64 pstart;
	__u64 pend;
	__u64 vstart;
	__u64 vend;

	__u64 target;

	__u64 flags;

	/*
	 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit'
	 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
	 * and maximum
	 */
	union {
		__u64 limit;		/* limit number of processed chunks */
		struct {
			__u32 limit_min;
			__u32 limit_max;
		};
	};
	__u32 stripes_min;
	__u32 stripes_max;
	__u64 unused[6];
} __attribute__ ((__packed__));

/* report balance progress to userspace */
struct btrfs_balance_progress {
	__u64 expected;		/* estimated # of chunks that will be
				 * relocated to fulfil the request */
	__u64 considered;	/* # of chunks we have considered so far */
	__u64 completed;	/* # of chunks relocated so far */
};

#define BTRFS_BALANCE_STATE_RUNNING	(1ULL << 0)
#define BTRFS_BALANCE_STATE_PAUSE_REQ	(1ULL << 1)
#define BTRFS_BALANCE_STATE_CANCEL_REQ	(1ULL << 2)

struct btrfs_ioctl_balance_args {
	__u64 flags;				/* in/out */
	__u64 state;				/* out */

	struct btrfs_balance_args data;		/* in/out */
	struct btrfs_balance_args meta;		/* in/out */
	struct btrfs_balance_args sys;		/* in/out */

	struct btrfs_balance_progress stat;	/* out */

	__u64 unused[72];			/* pad to 1k */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_balance_args) == 1024);

#define BTRFS_INO_LOOKUP_PATH_MAX 4080
struct btrfs_ioctl_ino_lookup_args {
	__u64 treeid;
	__u64 objectid;
	char name[BTRFS_INO_LOOKUP_PATH_MAX];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_ino_lookup_args) == 4096);

#define BTRFS_INO_LOOKUP_USER_PATH_MAX	(4080 - BTRFS_VOL_NAME_MAX - 1)
struct btrfs_ioctl_ino_lookup_user_args {
	/* in, inode number containing the subvolume of 'subvolid' */
	__u64 dirid;
	/* in */
	__u64 treeid;
	/* out, name of the subvolume of 'treeid' */
	char name[BTRFS_VOL_NAME_MAX + 1];
	/*
	 * out, constructed path from the directory with which the ioctl is
	 * called to dirid
	 */
	char path[BTRFS_INO_LOOKUP_USER_PATH_MAX];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_ino_lookup_user_args) == 4096);

struct btrfs_ioctl_search_key {
	/* which root are we searching.  0 is the tree of tree roots */
	__u64 tree_id;

	/* keys returned will be >= min and <= max */
	__u64 min_objectid;
	__u64 max_objectid;

	/* keys returned will be >= min and <= max */
	__u64 min_offset;
	__u64 max_offset;

	/* max and min transids to search for */
	__u64 min_transid;
	__u64 max_transid;

	/* keys returned will be >= min and <= max */
	__u32 min_type;
	__u32 max_type;

	/*
	 * how many items did userland ask for, and how many are we
	 * returning
	 */
	__u32 nr_items;

	/* align to 64 bits */
	__u32 unused;

	/* some extra for later */
	__u64 unused1;
	__u64 unused2;
	__u64 unused3;
	__u64 unused4;
};

struct btrfs_ioctl_search_header {
	__u64 transid;
	__u64 objectid;
	__u64 offset;
	__u32 type;
	__u32 len;
} __attribute__((may_alias));

#define BTRFS_SEARCH_ARGS_BUFSIZE (4096 - sizeof(struct btrfs_ioctl_search_key))
/*
 * the buf is an array of search headers where
 * each header is followed by the actual item
 * the type field is expanded to 32 bits for alignment
 */
struct btrfs_ioctl_search_args {
	struct btrfs_ioctl_search_key key;
	char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
};

/*
 * Extended version of TREE_SEARCH ioctl that can return more than 4k of bytes.
 * The allocated size of the buffer is set in buf_size.
 */
struct btrfs_ioctl_search_args_v2 {
        struct btrfs_ioctl_search_key key; /* in/out - search parameters */
        __u64 buf_size;			   /* in - size of buffer
                                            * out - on EOVERFLOW: needed size
                                            *       to store item */
        __u64 buf[0];                      /* out - found items */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_search_args_v2) == 112);

/* With a @src_length of zero, the range from @src_offset->EOF is cloned! */
struct btrfs_ioctl_clone_range_args {
	__s64 src_fd;
	__u64 src_offset, src_length;
	__u64 dest_offset;
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_clone_range_args) == 32);

/* flags for the defrag range ioctl */
#define BTRFS_DEFRAG_RANGE_COMPRESS 1
#define BTRFS_DEFRAG_RANGE_START_IO 2

#define BTRFS_SAME_DATA_DIFFERS	1
/* For extent-same ioctl */
struct btrfs_ioctl_same_extent_info {
	__s64 fd;		/* in - destination file */
	__u64 logical_offset;	/* in - start of extent in destination */
	__u64 bytes_deduped;	/* out - total # of bytes we were able
				 * to dedupe from this file */
	/* status of this dedupe operation:
	 * 0 if dedup succeeds
	 * < 0 for error
	 * == BTRFS_SAME_DATA_DIFFERS if data differs
	 */
	__s32 status;		/* out - see above description */
	__u32 reserved;
};

struct btrfs_ioctl_same_args {
	__u64 logical_offset;	/* in - start of extent in source */
	__u64 length;		/* in - length of extent */
	__u16 dest_count;	/* in - total elements in info array */
	__u16 reserved1;
	__u32 reserved2;
	struct btrfs_ioctl_same_extent_info info[0];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_same_args) == 24);

struct btrfs_ioctl_defrag_range_args {
	/* start of the defrag operation */
	__u64 start;

	/* number of bytes to defrag, use (u64)-1 to say all */
	__u64 len;

	/*
	 * flags for the operation, which can include turning
	 * on compression for this one defrag
	 */
	__u64 flags;

	/*
	 * any extent bigger than this will be considered
	 * already defragged.  Use 0 to take the kernel default
	 * Use 1 to say every single extent must be rewritten
	 */
	__u32 extent_thresh;

	/*
	 * which compression method to use if turning on compression
	 * for this defrag operation.  If unspecified, zlib will
	 * be used
	 */
	__u32 compress_type;

	/* spare for later */
	__u32 unused[4];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_defrag_range_args) == 48);

struct btrfs_ioctl_space_info {
	__u64 flags;
	__u64 total_bytes;
	__u64 used_bytes;
};

struct btrfs_ioctl_space_args {
	__u64 space_slots;
	__u64 total_spaces;
	struct btrfs_ioctl_space_info spaces[0];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_space_args) == 16);

struct btrfs_data_container {
	__u32	bytes_left;	/* out -- bytes not needed to deliver output */
	__u32	bytes_missing;	/* out -- additional bytes needed for result */
	__u32	elem_cnt;	/* out */
	__u32	elem_missed;	/* out */
	__u64	val[0];		/* out */
};

struct btrfs_ioctl_ino_path_args {
	__u64				inum;		/* in */
	__u64				size;		/* in */
	__u64				reserved[4];
	/* struct btrfs_data_container	*fspath;	   out */
	__u64				fspath;		/* out */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_ino_path_args) == 56);

struct btrfs_ioctl_logical_ino_args {
	__u64				logical;	/* in */
	__u64				size;		/* in */
	__u64				reserved[3];
	__u64				flags;		/* in */
	/* struct btrfs_data_container	*inodes;	out   */
	__u64				inodes;
};

/*
 * Return every ref to the extent, not just those containing logical block.
 * Requires logical == extent bytenr.
 */
#define BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET    (1ULL << 0)

enum btrfs_dev_stat_values {
	/* disk I/O failure stats */
	BTRFS_DEV_STAT_WRITE_ERRS, /* EIO or EREMOTEIO from lower layers */
	BTRFS_DEV_STAT_READ_ERRS, /* EIO or EREMOTEIO from lower layers */
	BTRFS_DEV_STAT_FLUSH_ERRS, /* EIO or EREMOTEIO from lower layers */

	/* stats for indirect indications for I/O failures */
	BTRFS_DEV_STAT_CORRUPTION_ERRS, /* checksum error, bytenr error or
					 * contents is illegal: this is an
					 * indication that the block was damaged
					 * during read or write, or written to
					 * wrong location or read from wrong
					 * location */
	BTRFS_DEV_STAT_GENERATION_ERRS, /* an indication that blocks have not
					 * been written */

	BTRFS_DEV_STAT_VALUES_MAX
};

/* Reset statistics after reading; needs SYS_ADMIN capability */
#define	BTRFS_DEV_STATS_RESET		(1ULL << 0)

struct btrfs_ioctl_get_dev_stats {
	__u64 devid;				/* in */
	__u64 nr_items;				/* in/out */
	__u64 flags;				/* in/out */

	/* out values: */
	__u64 values[BTRFS_DEV_STAT_VALUES_MAX];

	__u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX]; /* pad to 1k + 8B */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_get_dev_stats) == 1032);

/* BTRFS_IOC_SNAP_CREATE is no longer used by the btrfs command */
#define BTRFS_QUOTA_CTL_ENABLE	1
#define BTRFS_QUOTA_CTL_DISABLE	2
/* 3 has formerly been reserved for BTRFS_QUOTA_CTL_RESCAN */
struct btrfs_ioctl_quota_ctl_args {
	__u64 cmd;
	__u64 status;
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_quota_ctl_args) == 16);

struct btrfs_ioctl_quota_rescan_args {
	__u64	flags;
	__u64   progress;
	__u64   reserved[6];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_quota_rescan_args) == 64);

struct btrfs_ioctl_qgroup_assign_args {
	__u64 assign;
	__u64 src;
	__u64 dst;
};

struct btrfs_ioctl_qgroup_create_args {
	__u64 create;
	__u64 qgroupid;
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_qgroup_create_args) == 16);

struct btrfs_ioctl_timespec {
	__u64 sec;
	__u32 nsec;
};

struct btrfs_ioctl_received_subvol_args {
	char	uuid[BTRFS_UUID_SIZE];	/* in */
	__u64	stransid;		/* in */
	__u64	rtransid;		/* out */
	struct btrfs_ioctl_timespec stime; /* in */
	struct btrfs_ioctl_timespec rtime; /* out */
	__u64	flags;			/* in */
	__u64	reserved[16];		/* in */
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_received_subvol_args) == 200);

/*
 * If we have a 32-bit userspace and 64-bit kernel, then the UAPI
 * structures are incorrect, as the timespec structure from userspace
 * is 4 bytes too small. We define these alternatives here for backward
 * compatibility, the kernel understands both values.
 */

/*
 * Structure size is different on 32bit and 64bit, has some padding if the
 * structure is embedded. Packing makes sure the size is same on both, but will
 * be misaligned on 64bit.
 *
 * NOTE: do not use in your code, this is for testing only
 */
struct btrfs_ioctl_timespec_32 {
	__u64 sec;
	__u32 nsec;
} __attribute__ ((__packed__));

struct btrfs_ioctl_received_subvol_args_32 {
	char	uuid[BTRFS_UUID_SIZE];	/* in */
	__u64	stransid;		/* in */
	__u64	rtransid;		/* out */
	struct btrfs_ioctl_timespec_32 stime; /* in */
	struct btrfs_ioctl_timespec_32 rtime; /* out */
	__u64	flags;			/* in */
	__u64	reserved[16];		/* in */
} __attribute__ ((__packed__));
BUILD_ASSERT(sizeof(struct btrfs_ioctl_received_subvol_args_32) == 192);

#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32_COMPAT_DEFINED 1

/*
 * Caller doesn't want file data in the send stream, even if the
 * search of clone sources doesn't find an extent. UPDATE_EXTENT
 * commands will be sent instead of WRITE commands.
 */
#define BTRFS_SEND_FLAG_NO_FILE_DATA		0x1

/*
 * Do not add the leading stream header. Used when multiple snapshots
 * are sent back to back.
 */
#define BTRFS_SEND_FLAG_OMIT_STREAM_HEADER	0x2

/*
 * Omit the command at the end of the stream that indicated the end
 * of the stream. This option is used when multiple snapshots are
 * sent back to back.
 */
#define BTRFS_SEND_FLAG_OMIT_END_CMD		0x4

/*
 * Read the protocol version in the structure
 */
#define BTRFS_SEND_FLAG_VERSION			0x8

/*
 * Send compressed data using the ENCODED_WRITE command instead of decompressing
 * the data and sending it with the WRITE command. This requires protocol
 * version >= 2.
 */
#define BTRFS_SEND_FLAG_COMPRESSED		0x10

#define BTRFS_SEND_FLAG_MASK \
	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
	 BTRFS_SEND_FLAG_OMIT_END_CMD | \
	 BTRFS_SEND_FLAG_VERSION | \
	 BTRFS_SEND_FLAG_COMPRESSED)

struct btrfs_ioctl_send_args {
	__s64 send_fd;			/* in */
	__u64 clone_sources_count;	/* in */
	__u64 __user *clone_sources;	/* in */
	__u64 parent_root;		/* in */
	__u64 flags;			/* in */
	__u32 version;			/* in */
	__u8 reserved[28];		/* in */
};
/*
 * Size of structure depends on pointer width, was not caught in the early
 * days.  Kernel handles pointer width differences transparently.
 */
BUILD_ASSERT(sizeof(__u64 *) == 8
	     ? sizeof(struct btrfs_ioctl_send_args) == 72
	     : (sizeof(void *) == 4
		? sizeof(struct btrfs_ioctl_send_args) == 68
		: 0));

/*
 * Different pointer width leads to structure size change. Kernel should accept
 * both ioctl values (derived from the structures) for backward compatibility.
 * Size of this structure is same on 32bit and 64bit though.
 *
 * NOTE: do not use in your code, this is for testing only
 */
struct btrfs_ioctl_send_args_64 {
	__s64 send_fd;			/* in */
	__u64 clone_sources_count;	/* in */
	union {
		__u64 __user *clone_sources;	/* in */
		__u64 __clone_sources_alignment;
	};
	__u64 parent_root;		/* in */
	__u64 flags;			/* in */
	__u64 reserved[4];		/* in */
} __attribute__((packed));
BUILD_ASSERT(sizeof(struct btrfs_ioctl_send_args_64) == 72);

#define BTRFS_IOC_SEND_64_COMPAT_DEFINED 1

/*
 * Information about a fs tree root.
 *
 * All items are filled by the ioctl
 */
struct btrfs_ioctl_get_subvol_info_args {
	/* Id of this subvolume */
	__u64 treeid;

	/* Name of this subvolume, used to get the real name at mount point */
	char name[BTRFS_VOL_NAME_MAX + 1];

	/*
	 * Id of the subvolume which contains this subvolume.
	 * Zero for top-level subvolume or a deleted subvolume.
	 */
	__u64 parent_id;

	/*
	 * Inode number of the directory which contains this subvolume.
	 * Zero for top-level subvolume or a deleted subvolume
	 */
	__u64 dirid;

	/* Latest transaction id of this subvolume */
	__u64 generation;

	/* Flags of this subvolume */
	__u64 flags;

	/* UUID of this subvolume */
	__u8 uuid[BTRFS_UUID_SIZE];

	/*
	 * UUID of the subvolume of which this subvolume is a snapshot.
	 * All zero for a non-snapshot subvolume.
	 */
	__u8 parent_uuid[BTRFS_UUID_SIZE];

	/*
	 * UUID of the subvolume from which this subvolume was received.
	 * All zero for non-received subvolume.
	 */
	__u8 received_uuid[BTRFS_UUID_SIZE];

	/* Transaction id indicating when change/create/send/receive happened */
	__u64 ctransid;
	__u64 otransid;
	__u64 stransid;
	__u64 rtransid;
	/* Time corresponding to c/o/s/rtransid */
	struct btrfs_ioctl_timespec ctime;
	struct btrfs_ioctl_timespec otime;
	struct btrfs_ioctl_timespec stime;
	struct btrfs_ioctl_timespec rtime;

	/* Must be zero */
	__u64 reserved[8];
};

#define BTRFS_MAX_ROOTREF_BUFFER_NUM			255
struct btrfs_ioctl_get_subvol_rootref_args {
	/* in/out, minimum id of rootref's treeid to be searched */
	__u64 min_treeid;

	/* out */
	struct {
		__u64 treeid;
		__u64 dirid;
	} rootref[BTRFS_MAX_ROOTREF_BUFFER_NUM];

	/* out, number of found items */
	__u8 num_items;
	__u8 align[7];
};
BUILD_ASSERT(sizeof(struct btrfs_ioctl_get_subvol_rootref_args) == 4096);

/*
 * Data and metadata for an encoded read or write.
 *
 * Encoded I/O bypasses any encoding automatically done by the filesystem (e.g.,
 * compression). This can be used to read the compressed contents of a file or
 * write pre-compressed data directly to a file.
 *
 * BTRFS_IOC_ENCODED_READ and BTRFS_IOC_ENCODED_WRITE are essentially
 * preadv/pwritev with additional metadata about how the data is encoded and the
 * size of the unencoded data.
 *
 * BTRFS_IOC_ENCODED_READ fills the given iovecs with the encoded data, fills
 * the metadata fields, and returns the size of the encoded data. It reads one
 * extent per call. It can also read data which is not encoded.
 *
 * BTRFS_IOC_ENCODED_WRITE uses the metadata fields, writes the encoded data
 * from the iovecs, and returns the size of the encoded data. Note that the
 * encoded data is not validated when it is written; if it is not valid (e.g.,
 * it cannot be decompressed), then a subsequent read may return an error.
 *
 * Since the filesystem page cache contains decoded data, encoded I/O bypasses
 * the page cache. Encoded I/O requires CAP_SYS_ADMIN.
 */
struct btrfs_ioctl_encoded_io_args {
	/* Input parameters for both reads and writes. */

	/*
	 * iovecs containing encoded data.
	 *
	 * For reads, if the size of the encoded data is larger than the sum of
	 * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with
	 * ENOBUFS.
	 *
	 * For writes, the size of the encoded data is the sum of iov[n].iov_len
	 * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may
	 * increase in the future). This must also be less than or equal to
	 * unencoded_len.
	 */
	const struct iovec __user *iov;
	/* Number of iovecs. */
	unsigned long iovcnt;
	/*
	 * Offset in file.
	 *
	 * For writes, must be aligned to the sector size of the filesystem.
	 */
	__s64 offset;
	/* Currently must be zero. */
	__u64 flags;

	/*
	 * For reads, the following members are output parameters that will
	 * contain the returned metadata for the encoded data.
	 * For writes, the following members must be set to the metadata for the
	 * encoded data.
	 */

	/*
	 * Length of the data in the file.
	 *
	 * Must be less than or equal to unencoded_len - unencoded_offset. For
	 * writes, must be aligned to the sector size of the filesystem unless
	 * the data ends at or beyond the current end of the file.
	 */
	__u64 len;
	/*
	 * Length of the unencoded (i.e., decrypted and decompressed) data.
	 *
	 * For writes, must be no more than 128 KiB (this limit may increase in
	 * the future). If the unencoded data is actually longer than
	 * unencoded_len, then it is truncated; if it is shorter, then it is
	 * extended with zeroes.
	 */
	__u64 unencoded_len;
	/*
	 * Offset from the first byte of the unencoded data to the first byte of
	 * logical data in the file.
	 *
	 * Must be less than unencoded_len.
	 */
	__u64 unencoded_offset;
	/*
	 * BTRFS_ENCODED_IO_COMPRESSION_* type.
	 *
	 * For writes, must not be BTRFS_ENCODED_IO_COMPRESSION_NONE.
	 */
	__u32 compression;
	/* Currently always BTRFS_ENCODED_IO_ENCRYPTION_NONE. */
	__u32 encryption;
	/*
	 * Reserved for future expansion.
	 *
	 * For reads, always returned as zero. Users should check for non-zero
	 * bytes. If there are any, then the kernel has a newer version of this
	 * structure with additional information that the user definition is
	 * missing.
	 *
	 * For writes, must be zeroed.
	 */
	__u8 reserved[64];
};

/* Data is not compressed. */
#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0
/* Data is compressed as a single zlib stream. */
#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1
/*
 * Data is compressed as a single zstd frame with the windowLog compression
 * parameter set to no more than 17.
 */
#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2
/*
 * Data is compressed sector by sector (using the sector size indicated by the
 * name of the constant) with LZO1X and wrapped in the format documented in
 * fs/btrfs/lzo.c. For writes, the compression sector size must match the
 * filesystem sector size.
 */
#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3
#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4
#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5
#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6
#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7
#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8

/* Data is not encrypted. */
#define BTRFS_ENCODED_IO_ENCRYPTION_NONE 0
#define BTRFS_ENCODED_IO_ENCRYPTION_TYPES 1

/* Error codes as returned by the kernel */
enum btrfs_err_code {
	notused,
	BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
	BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
	BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
	BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
	BTRFS_ERROR_DEV_TGT_REPLACE,
	BTRFS_ERROR_DEV_MISSING_NOT_FOUND,
	BTRFS_ERROR_DEV_ONLY_WRITABLE,
	BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS,
	BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
	BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
};

/* An error code to error string mapping for the kernel
*  error codes
*/
static inline char *btrfs_err_str(enum btrfs_err_code err_code)
{
	switch (err_code) {
		case BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET:
			return "unable to go below two devices on raid1";
		case BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET:
			return "unable to go below three devices on raid1c3";
		case BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET:
			return "unable to go below four devices on raid1c4";
		case BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET:
			return "unable to go below four/two devices on raid10";
		case BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET:
			return "unable to go below two devices on raid5";
		case BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET:
			return "unable to go below three devices on raid6";
		case BTRFS_ERROR_DEV_TGT_REPLACE:
			return "unable to remove the dev_replace target dev";
		case BTRFS_ERROR_DEV_MISSING_NOT_FOUND:
			return "no missing devices found to remove";
		case BTRFS_ERROR_DEV_ONLY_WRITABLE:
			return "unable to remove the only writeable device";
		case BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS:
			return "add/delete/balance/replace/resize operation "
				"in progress";
		default:
			return NULL;
	}
}

#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_RESIZE _IOW(BTRFS_IOCTL_MAGIC, 3, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_FORGET_DEV _IOW(BTRFS_IOCTL_MAGIC, 5, \
				   struct btrfs_ioctl_vol_args)
/*
 * Removed in kernel since 4.17:
 * BTRFS_IOC_TRANS_START	_IO(BTRFS_IOCTL_MAGIC, 6)
 * BTRFS_IOC_TRANS_END		_IO(BTRFS_IOCTL_MAGIC, 7)
 */

#define BTRFS_IOC_SYNC         _IO(BTRFS_IOCTL_MAGIC, 8)

#define BTRFS_IOC_CLONE        _IOW(BTRFS_IOCTL_MAGIC, 9, int)
#define BTRFS_IOC_ADD_DEV _IOW(BTRFS_IOCTL_MAGIC, 10, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_RM_DEV _IOW(BTRFS_IOCTL_MAGIC, 11, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_BALANCE _IOW(BTRFS_IOCTL_MAGIC, 12, \
				   struct btrfs_ioctl_vol_args)

#define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
				   struct btrfs_ioctl_clone_range_args)

#define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
				   struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG_RANGE _IOW(BTRFS_IOCTL_MAGIC, 16, \
				struct btrfs_ioctl_defrag_range_args)
#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
				   struct btrfs_ioctl_search_args)
#define BTRFS_IOC_TREE_SEARCH_V2 _IOWR(BTRFS_IOCTL_MAGIC, 17, \
				   struct btrfs_ioctl_search_args_v2)
#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
				   struct btrfs_ioctl_ino_lookup_args)
#define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, __u64)
#define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
				    struct btrfs_ioctl_space_args)
#define BTRFS_IOC_START_SYNC _IOR(BTRFS_IOCTL_MAGIC, 24, __u64)
#define BTRFS_IOC_WAIT_SYNC  _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
				   struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_SUBVOL_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 24, \
				   struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_SUBVOL_GETFLAGS _IOR(BTRFS_IOCTL_MAGIC, 25, __u64)
#define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64)
#define BTRFS_IOC_SCRUB _IOWR(BTRFS_IOCTL_MAGIC, 27, \
				struct btrfs_ioctl_scrub_args)
#define BTRFS_IOC_SCRUB_CANCEL _IO(BTRFS_IOCTL_MAGIC, 28)
#define BTRFS_IOC_SCRUB_PROGRESS _IOWR(BTRFS_IOCTL_MAGIC, 29, \
					struct btrfs_ioctl_scrub_args)
#define BTRFS_IOC_DEV_INFO _IOWR(BTRFS_IOCTL_MAGIC, 30, \
					struct btrfs_ioctl_dev_info_args)
#define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
                                 struct btrfs_ioctl_fs_info_args)
#define BTRFS_IOC_BALANCE_V2 _IOWR(BTRFS_IOCTL_MAGIC, 32, \
				   struct btrfs_ioctl_balance_args)
#define BTRFS_IOC_BALANCE_CTL _IOW(BTRFS_IOCTL_MAGIC, 33, int)
#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 34, \
					struct btrfs_ioctl_balance_args)
#define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
					struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
					struct btrfs_ioctl_logical_ino_args)
#define BTRFS_IOC_SET_RECEIVED_SUBVOL _IOWR(BTRFS_IOCTL_MAGIC, 37, \
				struct btrfs_ioctl_received_subvol_args)

#ifdef BTRFS_IOC_SET_RECEIVED_SUBVOL_32_COMPAT_DEFINED
#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
				struct btrfs_ioctl_received_subvol_args_32)
#endif

#ifdef BTRFS_IOC_SEND_64_COMPAT_DEFINED
#define BTRFS_IOC_SEND_64 _IOW(BTRFS_IOCTL_MAGIC, 38, \
		struct btrfs_ioctl_send_args_64)
#endif

#define BTRFS_IOC_SEND _IOW(BTRFS_IOCTL_MAGIC, 38, struct btrfs_ioctl_send_args)
#define BTRFS_IOC_DEVICES_READY _IOR(BTRFS_IOCTL_MAGIC, 39, \
				     struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_QUOTA_CTL _IOWR(BTRFS_IOCTL_MAGIC, 40, \
					struct btrfs_ioctl_quota_ctl_args)
#define BTRFS_IOC_QGROUP_ASSIGN _IOW(BTRFS_IOCTL_MAGIC, 41, \
					struct btrfs_ioctl_qgroup_assign_args)
#define BTRFS_IOC_QGROUP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 42, \
					struct btrfs_ioctl_qgroup_create_args)
#define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \
					struct btrfs_ioctl_qgroup_limit_args)
#define BTRFS_IOC_QUOTA_RESCAN _IOW(BTRFS_IOCTL_MAGIC, 44, \
			       struct btrfs_ioctl_quota_rescan_args)
#define BTRFS_IOC_QUOTA_RESCAN_STATUS _IOR(BTRFS_IOCTL_MAGIC, 45, \
			       struct btrfs_ioctl_quota_rescan_args)
#define BTRFS_IOC_QUOTA_RESCAN_WAIT _IO(BTRFS_IOCTL_MAGIC, 46)
#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \
				   char[BTRFS_LABEL_SIZE])
#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 50, \
				   char[BTRFS_LABEL_SIZE])
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
				      struct btrfs_ioctl_get_dev_stats)
#define BTRFS_IOC_DEV_REPLACE _IOWR(BTRFS_IOCTL_MAGIC, 53, \
				    struct btrfs_ioctl_dev_replace_args)
#define BTRFS_IOC_FILE_EXTENT_SAME _IOWR(BTRFS_IOCTL_MAGIC, 54, \
					 struct btrfs_ioctl_same_args)
#define BTRFS_IOC_GET_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \
                                  struct btrfs_ioctl_feature_flags)
#define BTRFS_IOC_SET_FEATURES _IOW(BTRFS_IOCTL_MAGIC, 57, \
                                  struct btrfs_ioctl_feature_flags[2])
#define BTRFS_IOC_GET_SUPPORTED_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \
                                  struct btrfs_ioctl_feature_flags[3])
#define BTRFS_IOC_RM_DEV_V2	_IOW(BTRFS_IOCTL_MAGIC, 58, \
				   struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_LOGICAL_INO_V2 _IOWR(BTRFS_IOCTL_MAGIC, 59, \
                                     struct btrfs_ioctl_logical_ino_args)
#define BTRFS_IOC_GET_SUBVOL_INFO _IOR(BTRFS_IOCTL_MAGIC, 60, \
				struct btrfs_ioctl_get_subvol_info_args)
#define BTRFS_IOC_GET_SUBVOL_ROOTREF _IOWR(BTRFS_IOCTL_MAGIC, 61, \
				struct btrfs_ioctl_get_subvol_rootref_args)
#define BTRFS_IOC_INO_LOOKUP_USER _IOWR(BTRFS_IOCTL_MAGIC, 62, \
				struct btrfs_ioctl_ino_lookup_user_args)
#define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \
				   struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_ENCODED_READ _IOR(BTRFS_IOCTL_MAGIC, 64, \
				    struct btrfs_ioctl_encoded_io_args)
#define BTRFS_IOC_ENCODED_WRITE _IOW(BTRFS_IOCTL_MAGIC, 64, \
				     struct btrfs_ioctl_encoded_io_args)

#ifdef __cplusplus
}
#endif

#endif