mergerfs/libfuse/include/fuse_kernel.h

/*
    This file defines the kernel interface of FUSE
    Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>

    This program can be distributed under the terms of the GNU GPL.
    See the file COPYING.

    This -- and only this -- header file may also be distributed under
    the terms of the BSD Licence as follows:

    Copyright (C) 2001-2007 Miklos Szeredi. All rights reserved.

    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.

    THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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.
*/

/*
 * This file defines the kernel interface of FUSE
 *
 * Protocol changelog:
 *
 * 7.9:
 *  - new fuse_getattr_in input argument of GETATTR
 *  - add lk_flags in fuse_lk_in
 *  - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
 *  - add blksize field to fuse_attr
 *  - add file flags field to fuse_read_in and fuse_write_in
 *
 * 7.10
 *  - add nonseekable open flag
 *
 * 7.11
 *  - add IOCTL message
 *  - add unsolicited notification support
 *  - add POLL message and NOTIFY_POLL notification
 *
 * 7.12
 *  - add umask flag to input argument of open, mknod and mkdir
 *  - add notification messages for invalidation of inodes and
 *    directory entries
 *
 * 7.13
 *  - make max number of background requests and congestion threshold
 *    tunables
 *
 * 7.14
 *  - add splice support to fuse device
 *
 * 7.15
 *  - add store notify
 *  - add retrieve notify
 *
 * 7.16
 *  - add BATCH_FORGET request
 *  - FUSE_IOCTL_UNRESTRICTED shall now return with array of 'struct
 *    fuse_ioctl_iovec' instead of ambiguous 'struct iovec'
 *  - add FUSE_IOCTL_32BIT flag
 *
 * 7.17
 *  - add FUSE_FLOCK_LOCKS and FUSE_RELEASE_FLOCK_UNLOCK
 *
 * 7.18
 *  - add FUSE_IOCTL_DIR flag
 *  - add FUSE_NOTIFY_DELETE
 *
 * 7.19
 *  - add FUSE_FALLOCATE
 */

#ifndef _LINUX_FUSE_H
#define _LINUX_FUSE_H

#include <linux/types.h>
#include <sys/types.h>

/*
 * Version negotiation:
 *
 * Both the kernel and userspace send the version they support in the
 * INIT request and reply respectively.
 *
 * If the major versions match then both shall use the smallest
 * of the two minor versions for communication.
 *
 * If the kernel supports a larger major version, then userspace shall
 * reply with the major version it supports, ignore the rest of the
 * INIT message and expect a new INIT message from the kernel with a
 * matching major version.
 *
 * If the library supports a larger major version, then it shall fall
 * back to the major protocol version sent by the kernel for
 * communication and reply with that major version (and an arbitrary
 * supported minor version).
 */

/** Version number of this interface */
#define FUSE_KERNEL_VERSION 7

/** Minor version number of this interface */
#define FUSE_KERNEL_MINOR_VERSION 19

/** The node ID of the root inode */
#define FUSE_ROOT_ID 1

/* Make sure all structures are padded to 64bit boundary, so 32bit
   userspace works under 64bit kernels */

struct fuse_attr {
	__u64	ino;
	__u64	size;
	__u64	blocks;
	__u64	atime;
	__u64	mtime;
	__u64	ctime;
	__u32	atimensec;
	__u32	mtimensec;
	__u32	ctimensec;
	__u32	mode;
	__u32	nlink;
	__u32	uid;
	__u32	gid;
	__u32	rdev;
	__u32	blksize;
	__u32	padding;
};

struct fuse_kstatfs {
	__u64	blocks;
	__u64	bfree;
	__u64	bavail;
	__u64	files;
	__u64	ffree;
	__u32	bsize;
	__u32	namelen;
	__u32	frsize;
	__u32	padding;
	__u32	spare[6];
};

struct fuse_file_lock {
	__u64	start;
	__u64	end;
	__u32	type;
	__u32	pid; /* tgid */
};

/**
 * Bitmasks for fuse_setattr_in.valid
 */
#define FATTR_MODE	(1 << 0)
#define FATTR_UID	(1 << 1)
#define FATTR_GID	(1 << 2)
#define FATTR_SIZE	(1 << 3)
#define FATTR_ATIME	(1 << 4)
#define FATTR_MTIME	(1 << 5)
#define FATTR_FH	(1 << 6)
#define FATTR_ATIME_NOW	(1 << 7)
#define FATTR_MTIME_NOW	(1 << 8)
#define FATTR_LOCKOWNER	(1 << 9)

/**
 * Flags returned by the OPEN request
 *
 * FOPEN_DIRECT_IO: bypass page cache for this open file
 * FOPEN_KEEP_CACHE: don't invalidate the data cache on open
 * FOPEN_NONSEEKABLE: the file is not seekable
 */
#define FOPEN_DIRECT_IO		(1 << 0)
#define FOPEN_KEEP_CACHE	(1 << 1)
#define FOPEN_NONSEEKABLE	(1 << 2)

/**
 * INIT request/reply flags
 *
 * FUSE_POSIX_LOCKS: remote locking for POSIX file locks
 * FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
 * FUSE_DONT_MASK: don't apply umask to file mode on create operations
 * FUSE_FLOCK_LOCKS: remote locking for BSD style file locks
 */
#define FUSE_ASYNC_READ		(1 << 0)
#define FUSE_POSIX_LOCKS	(1 << 1)
#define FUSE_FILE_OPS		(1 << 2)
#define FUSE_ATOMIC_O_TRUNC	(1 << 3)
#define FUSE_EXPORT_SUPPORT	(1 << 4)
#define FUSE_BIG_WRITES		(1 << 5)
#define FUSE_DONT_MASK		(1 << 6)
#define FUSE_FLOCK_LOCKS	(1 << 10)

/**
 * CUSE INIT request/reply flags
 *
 * CUSE_UNRESTRICTED_IOCTL:  use unrestricted ioctl
 */
#define CUSE_UNRESTRICTED_IOCTL	(1 << 0)

/**
 * Release flags
 */
#define FUSE_RELEASE_FLUSH	(1 << 0)
#define FUSE_RELEASE_FLOCK_UNLOCK	(1 << 1)

/**
 * Getattr flags
 */
#define FUSE_GETATTR_FH		(1 << 0)

/**
 * Lock flags
 */
#define FUSE_LK_FLOCK		(1 << 0)

/**
 * WRITE flags
 *
 * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
 * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
 */
#define FUSE_WRITE_CACHE	(1 << 0)
#define FUSE_WRITE_LOCKOWNER	(1 << 1)

/**
 * Read flags
 */
#define FUSE_READ_LOCKOWNER	(1 << 1)

/**
 * Ioctl flags
 *
 * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
 * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
 * FUSE_IOCTL_RETRY: retry with new iovecs
 * FUSE_IOCTL_32BIT: 32bit ioctl
 * FUSE_IOCTL_DIR: is a directory
 *
 * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
 */
#define FUSE_IOCTL_COMPAT	(1 << 0)
#define FUSE_IOCTL_UNRESTRICTED	(1 << 1)
#define FUSE_IOCTL_RETRY	(1 << 2)
#define FUSE_IOCTL_32BIT	(1 << 3)
#define FUSE_IOCTL_DIR		(1 << 4)

#define FUSE_IOCTL_MAX_IOV	256

/**
 * Poll flags
 *
 * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
 */
#define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)

enum fuse_opcode {
	FUSE_LOOKUP	   = 1,
	FUSE_FORGET	   = 2,  /* no reply */
	FUSE_GETATTR	   = 3,
	FUSE_SETATTR	   = 4,
	FUSE_READLINK	   = 5,
	FUSE_SYMLINK	   = 6,
	FUSE_MKNOD	   = 8,
	FUSE_MKDIR	   = 9,
	FUSE_UNLINK	   = 10,
	FUSE_RMDIR	   = 11,
	FUSE_RENAME	   = 12,
	FUSE_LINK	   = 13,
	FUSE_OPEN	   = 14,
	FUSE_READ	   = 15,
	FUSE_WRITE	   = 16,
	FUSE_STATFS	   = 17,
	FUSE_RELEASE       = 18,
	FUSE_FSYNC         = 20,
	FUSE_SETXATTR      = 21,
	FUSE_GETXATTR      = 22,
	FUSE_LISTXATTR     = 23,
	FUSE_REMOVEXATTR   = 24,
	FUSE_FLUSH         = 25,
	FUSE_INIT          = 26,
	FUSE_OPENDIR       = 27,
	FUSE_READDIR       = 28,
	FUSE_RELEASEDIR    = 29,
	FUSE_FSYNCDIR      = 30,
	FUSE_GETLK         = 31,
	FUSE_SETLK         = 32,
	FUSE_SETLKW        = 33,
	FUSE_ACCESS        = 34,
	FUSE_CREATE        = 35,
	FUSE_INTERRUPT     = 36,
	FUSE_BMAP          = 37,
	FUSE_DESTROY       = 38,
	FUSE_IOCTL         = 39,
	FUSE_POLL          = 40,
	FUSE_NOTIFY_REPLY  = 41,
	FUSE_BATCH_FORGET  = 42,
	FUSE_FALLOCATE     = 43,

	/* CUSE specific operations */
	CUSE_INIT          = 4096,
};

enum fuse_notify_code {
	FUSE_NOTIFY_POLL   = 1,
	FUSE_NOTIFY_INVAL_INODE = 2,
	FUSE_NOTIFY_INVAL_ENTRY = 3,
	FUSE_NOTIFY_STORE = 4,
	FUSE_NOTIFY_RETRIEVE = 5,
	FUSE_NOTIFY_DELETE = 6,
	FUSE_NOTIFY_CODE_MAX,
};

/* The read buffer is required to be at least 8k, but may be much larger */
#define FUSE_MIN_READ_BUFFER 8192

#define FUSE_COMPAT_ENTRY_OUT_SIZE 120

struct fuse_entry_out {
	__u64	nodeid;		/* Inode ID */
	__u64	generation;	/* Inode generation: nodeid:gen must
				   be unique for the fs's lifetime */
	__u64	entry_valid;	/* Cache timeout for the name */
	__u64	attr_valid;	/* Cache timeout for the attributes */
	__u32	entry_valid_nsec;
	__u32	attr_valid_nsec;
	struct fuse_attr attr;
};

struct fuse_forget_in {
	__u64	nlookup;
};

struct fuse_forget_one {
	__u64	nodeid;
	__u64	nlookup;
};

struct fuse_batch_forget_in {
	__u32	count;
	__u32	dummy;
};

struct fuse_getattr_in {
	__u32	getattr_flags;
	__u32	dummy;
	__u64	fh;
};

#define FUSE_COMPAT_ATTR_OUT_SIZE 96

struct fuse_attr_out {
	__u64	attr_valid;	/* Cache timeout for the attributes */
	__u32	attr_valid_nsec;
	__u32	dummy;
	struct fuse_attr attr;
};

#define FUSE_COMPAT_MKNOD_IN_SIZE 8

struct fuse_mknod_in {
	__u32	mode;
	__u32	rdev;
	__u32	umask;
	__u32	padding;
};

struct fuse_mkdir_in {
	__u32	mode;
	__u32	umask;
};

struct fuse_rename_in {
	__u64	newdir;
};

struct fuse_link_in {
	__u64	oldnodeid;
};

struct fuse_setattr_in {
	__u32	valid;
	__u32	padding;
	__u64	fh;
	__u64	size;
	__u64	lock_owner;
	__u64	atime;
	__u64	mtime;
	__u64	unused2;
	__u32	atimensec;
	__u32	mtimensec;
	__u32	unused3;
	__u32	mode;
	__u32	unused4;
	__u32	uid;
	__u32	gid;
	__u32	unused5;
};

struct fuse_open_in {
	__u32	flags;
	__u32	unused;
};

struct fuse_create_in {
	__u32	flags;
	__u32	mode;
	__u32	umask;
	__u32	padding;
};

struct fuse_open_out {
	__u64	fh;
	__u32	open_flags;
	__u32	padding;
};

struct fuse_release_in {
	__u64	fh;
	__u32	flags;
	__u32	release_flags;
	__u64	lock_owner;
};

struct fuse_flush_in {
	__u64	fh;
	__u32	unused;
	__u32	padding;
	__u64	lock_owner;
};

struct fuse_read_in {
	__u64	fh;
	__u64	offset;
	__u32	size;
	__u32	read_flags;
	__u64	lock_owner;
	__u32	flags;
	__u32	padding;
};

#define FUSE_COMPAT_WRITE_IN_SIZE 24

struct fuse_write_in {
	__u64	fh;
	__u64	offset;
	__u32	size;
	__u32	write_flags;
	__u64	lock_owner;
	__u32	flags;
	__u32	padding;
};

struct fuse_write_out {
	__u32	size;
	__u32	padding;
};

#define FUSE_COMPAT_STATFS_SIZE 48

struct fuse_statfs_out {
	struct fuse_kstatfs st;
};

struct fuse_fsync_in {
	__u64	fh;
	__u32	fsync_flags;
	__u32	padding;
};

struct fuse_setxattr_in {
	__u32	size;
	__u32	flags;
};

struct fuse_getxattr_in {
	__u32	size;
	__u32	padding;
};

struct fuse_getxattr_out {
	__u32	size;
	__u32	padding;
};

struct fuse_lk_in {
	__u64	fh;
	__u64	owner;
	struct fuse_file_lock lk;
	__u32	lk_flags;
	__u32	padding;
};

struct fuse_lk_out {
	struct fuse_file_lock lk;
};

struct fuse_access_in {
	__u32	mask;
	__u32	padding;
};

struct fuse_init_in {
	__u32	major;
	__u32	minor;
	__u32	max_readahead;
	__u32	flags;
};

struct fuse_init_out {
	__u32	major;
	__u32	minor;
	__u32	max_readahead;
	__u32	flags;
	__u16   max_background;
	__u16   congestion_threshold;
	__u32	max_write;
};

#define CUSE_INIT_INFO_MAX 4096

struct cuse_init_in {
	__u32	major;
	__u32	minor;
	__u32	unused;
	__u32	flags;
};

struct cuse_init_out {
	__u32	major;
	__u32	minor;
	__u32	unused;
	__u32	flags;
	__u32	max_read;
	__u32	max_write;
	__u32	dev_major;		/* chardev major */
	__u32	dev_minor;		/* chardev minor */
	__u32	spare[10];
};

struct fuse_interrupt_in {
	__u64	unique;
};

struct fuse_bmap_in {
	__u64	block;
	__u32	blocksize;
	__u32	padding;
};

struct fuse_bmap_out {
	__u64	block;
};

struct fuse_ioctl_in {
	__u64	fh;
	__u32	flags;
	__u32	cmd;
	__u64	arg;
	__u32	in_size;
	__u32	out_size;
};

struct fuse_ioctl_iovec {
	__u64	base;
	__u64	len;
};

struct fuse_ioctl_out {
	__s32	result;
	__u32	flags;
	__u32	in_iovs;
	__u32	out_iovs;
};

struct fuse_poll_in {
	__u64	fh;
	__u64	kh;
	__u32	flags;
	__u32   padding;
};

struct fuse_poll_out {
	__u32	revents;
	__u32	padding;
};

struct fuse_notify_poll_wakeup_out {
	__u64	kh;
};

struct fuse_fallocate_in {
	__u64	fh;
	__u64	offset;
	__u64	length;
	__u32	mode;
	__u32	padding;
};

struct fuse_in_header {
	__u32	len;
	__u32	opcode;
	__u64	unique;
	__u64	nodeid;
	__u32	uid;
	__u32	gid;
	__u32	pid;
	__u32	padding;
};

struct fuse_out_header {
	__u32	len;
	__s32	error;
	__u64	unique;
};

struct fuse_dirent {
	__u64	ino;
	__u64	off;
	__u32	namelen;
	__u32	type;
	char name[];
};

#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
#define FUSE_DIRENT_ALIGN(x) (((x) + sizeof(__u64) - 1) & ~(sizeof(__u64) - 1))
#define FUSE_DIRENT_SIZE(d) \
	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)

struct fuse_notify_inval_inode_out {
	__u64	ino;
	__s64	off;
	__s64	len;
};

struct fuse_notify_inval_entry_out {
	__u64	parent;
	__u32	namelen;
	__u32	padding;
};

struct fuse_notify_delete_out {
	__u64	parent;
	__u64	child;
	__u32	namelen;
	__u32	padding;
};

struct fuse_notify_store_out {
	__u64	nodeid;
	__u64	offset;
	__u32	size;
	__u32	padding;
};

struct fuse_notify_retrieve_out {
	__u64	notify_unique;
	__u64	nodeid;
	__u64	offset;
	__u32	size;
	__u32	padding;
};

/* Matches the size of fuse_write_in */
struct fuse_notify_retrieve_in {
	__u64	dummy1;
	__u64	offset;
	__u32	size;
	__u32	dummy2;
	__u64	dummy3;
	__u64	dummy4;
};

#endif /* _LINUX_FUSE_H */