/*
    FUSE: Filesystem in Userspace
    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 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
 */

#ifndef _LINUX_FUSE_H
#define _LINUX_FUSE_H

#include <linux/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 15

/** 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_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
 * FUSE_DONT_MASK: don't apply umask to file mode on create operations
 */
#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)

/**
 * 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)

/**
 * 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_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_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,

        /* 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_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_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_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_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[0];
};

#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_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 */