/*
	 * ceph_fs.h - Ceph constants and data types to share between kernel and
	 * user space.
	 *
	 * Most types in this file are defined as little-endian, and are
	 * primarily intended to describe data structures that pass over the
	 * wire or that are stored on disk.
	 *
	 * LGPL-2.1 or LGPL-3.0
	 */
	
	#ifndef CEPH_FS_H
	#define CEPH_FS_H
	
	#include "msgr.h"
	#include "rados.h"
	
	/*
	 * The data structures defined here are shared between Linux kernel and
	 * user space.  Also, those data structures are maintained always in
	 * little-endian byte order, even on big-endian systems.  This is handled
	 * differently in kernel vs. user space.  For use as kernel headers, the
	 * little-endian fields need to use the __le16/__le32/__le64 types.  These
	 * are markers that indicate endian conversion routines must be used
	 * whenever such fields are accessed, which can be verified by checker
	 * tools like "sparse".  For use as user-space headers, the little-endian
	 * fields instead use types ceph_le16/ceph_le32/ceph_le64, which are C++
	 * classes that implement automatic endian conversion on every access.
	 * To still allow for header sharing, this file uses the __le types, but
	 * redefines those to the ceph_ types when compiled in user space.
	 */
	#ifndef __KERNEL__
	#include "byteorder.h"
	#define __le16 ceph_le16
	#define __le32 ceph_le32
	#define __le64 ceph_le64
	#endif
	
	/*
	 * subprotocol versions.  when specific messages types or high-level
	 * protocols change, bump the affected components.  we keep rev
	 * internal cluster protocols separately from the public,
	 * client-facing protocol.
	 */
	#define CEPH_OSDC_PROTOCOL   24 /* server/client */
	#define CEPH_MDSC_PROTOCOL   32 /* server/client */
	#define CEPH_MONC_PROTOCOL   15 /* server/client */
	
	
	#define CEPH_INO_ROOT   1
	#define CEPH_INO_CEPH   2       /* hidden .ceph dir */
	#define CEPH_INO_LOST_AND_FOUND 4	/* reserved ino for use in recovery */
	
	/* arbitrary limit on max # of monitors (cluster of 3 is typical) */
	#define CEPH_MAX_MON   31
	
	/*
	 * ceph_file_layout - describe data layout for a file/inode
	 */
	struct ceph_file_layout {
		/* file -> object mapping */
		__le32 fl_stripe_unit;     /* stripe unit, in bytes.  must be multiple
					      of page size. */
		__le32 fl_stripe_count;    /* over this many objects */
		__le32 fl_object_size;     /* until objects are this big, then move to
					      new objects */
		__le32 fl_cas_hash;        /* UNUSED.  0 = none; 1 = sha256 */
	
		/* pg -> disk layout */
		__le32 fl_object_stripe_unit;  /* UNUSED.  for per-object parity, if any */
	
		/* object -> pg layout */
		__le32 fl_unused;       /* unused; used to be preferred primary for pg (-1 for none) */
		__le32 fl_pg_pool;      /* namespace, crush ruleset, rep level */
	} __attribute__ ((packed));
	
	#define CEPH_MIN_STRIPE_UNIT 65536
	
	struct ceph_dir_layout {
		__u8   dl_dir_hash;   /* see ceph_hash.h for ids */
		__u8   dl_unused1;
		__u16  dl_unused2;
		__u32  dl_unused3;
	} __attribute__ ((packed));
	
	/* crypto algorithms */
	#define CEPH_CRYPTO_NONE 0x0
	#define CEPH_CRYPTO_AES  0x1
	
	#define CEPH_AES_IV "cephsageyudagreg"
	
	/* security/authentication protocols */
	#define CEPH_AUTH_UNKNOWN	0x0
	#define CEPH_AUTH_NONE	 	0x1
	#define CEPH_AUTH_CEPHX	 	0x2
	
	/* msgr2 protocol modes */
	#define CEPH_CON_MODE_UNKNOWN 0x0
	#define CEPH_CON_MODE_CRC     0x1
	#define CEPH_CON_MODE_SECURE  0x2
	
	extern const char *ceph_con_mode_name(int con_mode);
	
	/*  For options with "_", like: GSS_GSS
	    which means: Mode/Protocol to validate "authentication_authorization",
	    where:
	      - Authentication: Verifying the identity of an entity.
	      - Authorization:  Verifying that an authenticated entity has
	                        the right to access a particular resource.
	*/ 
	#define CEPH_AUTH_GSS     0x4
	#define CEPH_AUTH_GSS_GSS CEPH_AUTH_GSS
	
	#define CEPH_AUTH_UID_DEFAULT ((__u64) -1)
	
	
	/*********************************************
	 * message layer
	 */
	
	/*
	 * message types
	 */
	
	/* misc */
	#define CEPH_MSG_SHUTDOWN               1
	#define CEPH_MSG_PING                   2
	
	/* client <-> monitor */
	#define CEPH_MSG_MON_MAP                4
	#define CEPH_MSG_MON_GET_MAP            5
	#define CEPH_MSG_MON_GET_OSDMAP         6
	#define CEPH_MSG_MON_METADATA           7
	#define CEPH_MSG_STATFS                 13
	#define CEPH_MSG_STATFS_REPLY           14
	#define CEPH_MSG_MON_SUBSCRIBE          15
	#define CEPH_MSG_MON_SUBSCRIBE_ACK      16
	#define CEPH_MSG_AUTH			17
	#define CEPH_MSG_AUTH_REPLY		18
	#define CEPH_MSG_MON_GET_VERSION        19
	#define CEPH_MSG_MON_GET_VERSION_REPLY  20
	
	/* client <-> mds */
	#define CEPH_MSG_MDS_MAP                21
	
	#define CEPH_MSG_CLIENT_SESSION         22
	#define CEPH_MSG_CLIENT_RECONNECT       23
	
	#define CEPH_MSG_CLIENT_REQUEST         24
	#define CEPH_MSG_CLIENT_REQUEST_FORWARD 25
	#define CEPH_MSG_CLIENT_REPLY           26
	#define CEPH_MSG_CLIENT_RECLAIM		27
	#define CEPH_MSG_CLIENT_RECLAIM_REPLY   28
	#define CEPH_MSG_CLIENT_CAPS            0x310
	#define CEPH_MSG_CLIENT_LEASE           0x311
	#define CEPH_MSG_CLIENT_SNAP            0x312
	#define CEPH_MSG_CLIENT_CAPRELEASE      0x313
	#define CEPH_MSG_CLIENT_QUOTA           0x314
	
	/* pool ops */
	#define CEPH_MSG_POOLOP_REPLY           48
	#define CEPH_MSG_POOLOP                 49
	
	
	/* osd */
	#define CEPH_MSG_OSD_MAP                41
	#define CEPH_MSG_OSD_OP                 42
	#define CEPH_MSG_OSD_OPREPLY            43
	#define CEPH_MSG_WATCH_NOTIFY           44
	#define CEPH_MSG_OSD_BACKOFF            61
	
	/* FSMap subscribers (see all MDS clusters at once) */
	#define CEPH_MSG_FS_MAP                 45
	/* FSMapUser subscribers (get MDS clusters name->ID mapping) */
	#define CEPH_MSG_FS_MAP_USER		103
	
	/* watch-notify operations */
	enum {
		CEPH_WATCH_EVENT_NOTIFY		  = 1, /* notifying watcher */
		CEPH_WATCH_EVENT_NOTIFY_COMPLETE  = 2, /* notifier notified when done */
		CEPH_WATCH_EVENT_DISCONNECT       = 3, /* we were disconnected */
	};
	
	const char *ceph_watch_event_name(int o);
	
	/* pool operations */
	enum {
	  POOL_OP_CREATE			= 0x01,
	  POOL_OP_DELETE			= 0x02,
	  POOL_OP_AUID_CHANGE			= 0x03,
	  POOL_OP_CREATE_SNAP			= 0x11,
	  POOL_OP_DELETE_SNAP			= 0x12,
	  POOL_OP_CREATE_UNMANAGED_SNAP		= 0x21,
	  POOL_OP_DELETE_UNMANAGED_SNAP		= 0x22,
	};
	
	struct ceph_mon_request_header {
		__le64 have_version;
		__le16 session_mon;
		__le64 session_mon_tid;
	} __attribute__ ((packed));
	
	struct ceph_mon_statfs {
		struct ceph_mon_request_header monhdr;
		struct ceph_fsid fsid;
	} __attribute__ ((packed));
	
	struct ceph_statfs {
		__le64 kb, kb_used, kb_avail;
		__le64 num_objects;
	} __attribute__ ((packed));
	
	struct ceph_mon_statfs_reply {
		struct ceph_fsid fsid;
		__le64 version;
		struct ceph_statfs st;
	} __attribute__ ((packed));
	
	const char *ceph_pool_op_name(int op);
	
	struct ceph_mon_poolop {
		struct ceph_mon_request_header monhdr;
		struct ceph_fsid fsid;
		__le32 pool;
		__le32 op;
		__le64 __old_auid;  // obsolete
		__le64 snapid;
		__le32 name_len;
	} __attribute__ ((packed));
	
	struct ceph_mon_poolop_reply {
		struct ceph_mon_request_header monhdr;
		struct ceph_fsid fsid;
		__le32 reply_code;
		__le32 epoch;
		char has_data;
		char data[0];
	} __attribute__ ((packed));
	
	struct ceph_mon_unmanaged_snap {
		__le64 snapid;
	} __attribute__ ((packed));
	
	struct ceph_osd_getmap {
		struct ceph_mon_request_header monhdr;
		struct ceph_fsid fsid;
		__le32 start;
	} __attribute__ ((packed));
	
	struct ceph_mds_getmap {
		struct ceph_mon_request_header monhdr;
		struct ceph_fsid fsid;
	} __attribute__ ((packed));
	
	struct ceph_client_mount {
		struct ceph_mon_request_header monhdr;
	} __attribute__ ((packed));
	
	#define CEPH_SUBSCRIBE_ONETIME    1  /* i want only 1 update after have */
	
	struct ceph_mon_subscribe_item {
		__le64 start;
		__u8 flags;
	} __attribute__ ((packed));
	
	struct ceph_mon_subscribe_ack {
		__le32 duration;         /* seconds */
		struct ceph_fsid fsid;
	} __attribute__ ((packed));
	
	/*
	 * mdsmap flags
	 */
	#define CEPH_MDSMAP_NOT_JOINABLE                 (1<<0)  /* standbys cannot join */
	#define CEPH_MDSMAP_DOWN                         (CEPH_MDSMAP_NOT_JOINABLE) /* backwards compat */
	#define CEPH_MDSMAP_ALLOW_SNAPS                  (1<<1)  /* cluster allowed to create snapshots */
	/* deprecated #define CEPH_MDSMAP_ALLOW_MULTIMDS (1<<2) cluster allowed to have >1 active MDS */
	/* deprecated #define CEPH_MDSMAP_ALLOW_DIRFRAGS (1<<3) cluster allowed to fragment directories */
	#define CEPH_MDSMAP_ALLOW_MULTIMDS_SNAPS	     (1<<4)  /* cluster alllowed to enable MULTIMDS
	                                                            and SNAPS at the same time */
	#define CEPH_MDSMAP_ALLOW_STANDBY_REPLAY         (1<<5)  /* cluster alllowed to enable MULTIMDS */
	
	#define CEPH_MDSMAP_DEFAULTS (CEPH_MDSMAP_ALLOW_SNAPS | \
				      CEPH_MDSMAP_ALLOW_MULTIMDS_SNAPS)
	
	/*
	 * mds states
	 *   > 0 -> in
	 *  <= 0 -> out
	 */
	#define CEPH_MDS_STATE_DNE          0  /* down, does not exist. */
	#define CEPH_MDS_STATE_STOPPED     -1  /* down, once existed, but no subtrees.
						  empty log. */
	#define CEPH_MDS_STATE_BOOT        -4  /* up, boot announcement. */
	#define CEPH_MDS_STATE_STANDBY     -5  /* up, idle.  waiting for assignment. */
	#define CEPH_MDS_STATE_CREATING    -6  /* up, creating MDS instance. */
	#define CEPH_MDS_STATE_STARTING    -7  /* up, starting previously stopped mds */
	#define CEPH_MDS_STATE_STANDBY_REPLAY -8 /* up, tailing active node's journal */
	#define CEPH_MDS_STATE_REPLAYONCE   -9 /* Legacy, unused */
	#define CEPH_MDS_STATE_NULL         -10
	
	#define CEPH_MDS_STATE_REPLAY       8  /* up, replaying journal. */
	#define CEPH_MDS_STATE_RESOLVE      9  /* up, disambiguating distributed
						  operations (import, rename, etc.) */
	#define CEPH_MDS_STATE_RECONNECT    10 /* up, reconnect to clients */
	#define CEPH_MDS_STATE_REJOIN       11 /* up, rejoining distributed cache */
	#define CEPH_MDS_STATE_CLIENTREPLAY 12 /* up, replaying client operations */
	#define CEPH_MDS_STATE_ACTIVE       13 /* up, active */
	#define CEPH_MDS_STATE_STOPPING     14 /* up, but exporting metadata */
	#define CEPH_MDS_STATE_DAMAGED      15 /* rank not replayable, need repair */
	
	extern const char *ceph_mds_state_name(int s);
	
	
	/*
	 * metadata lock types.
	 *  - these are bitmasks.. we can compose them
	 *  - they also define the lock ordering by the MDS
	 *  - a few of these are internal to the mds
	 */
	#define CEPH_LOCK_DVERSION    1
	#define CEPH_LOCK_DN          2
	#define CEPH_LOCK_IVERSION    16    /* mds internal */
	#define CEPH_LOCK_ISNAP       32
	#define CEPH_LOCK_IFILE       64
	#define CEPH_LOCK_IAUTH       128
	#define CEPH_LOCK_ILINK       256
	#define CEPH_LOCK_IDFT        512   /* dir frag tree */
	#define CEPH_LOCK_INEST       1024  /* mds internal */
	#define CEPH_LOCK_IXATTR      2048
	#define CEPH_LOCK_IFLOCK      4096  /* advisory file locks */
	#define CEPH_LOCK_INO         8192  /* immutable inode bits; not a lock */
	#define CEPH_LOCK_IPOLICY     16384 /* policy lock on dirs. MDS internal */
	
	/* client_session ops */
	enum {
		CEPH_SESSION_REQUEST_OPEN,
		CEPH_SESSION_OPEN,
		CEPH_SESSION_REQUEST_CLOSE,
		CEPH_SESSION_CLOSE,
		CEPH_SESSION_REQUEST_RENEWCAPS,
		CEPH_SESSION_RENEWCAPS,
		CEPH_SESSION_STALE,
		CEPH_SESSION_RECALL_STATE,
		CEPH_SESSION_FLUSHMSG,
		CEPH_SESSION_FLUSHMSG_ACK,
		CEPH_SESSION_FORCE_RO,
	    // A response to REQUEST_OPEN indicating that the client should
	    // permanently desist from contacting the MDS
		CEPH_SESSION_REJECT,
	        CEPH_SESSION_REQUEST_FLUSH_MDLOG
	};
	
	// flags for state reclaim
	#define CEPH_RECLAIM_RESET	1
	
	extern const char *ceph_session_op_name(int op);
	
	struct ceph_mds_session_head {
		__le32 op;
		__le64 seq;
		struct ceph_timespec stamp;
		__le32 max_caps, max_leases;
	} __attribute__ ((packed));
	
	/* client_request */
	/*
	 * metadata ops.
	 *  & 0x001000 -> write op
	 *  & 0x010000 -> follow symlink (e.g. stat(), not lstat()).
	 &  & 0x100000 -> use weird ino/path trace
	 */
	#define CEPH_MDS_OP_WRITE        0x001000
	enum {
		CEPH_MDS_OP_LOOKUP     = 0x00100,
		CEPH_MDS_OP_GETATTR    = 0x00101,
		CEPH_MDS_OP_LOOKUPHASH = 0x00102,
		CEPH_MDS_OP_LOOKUPPARENT = 0x00103,
		CEPH_MDS_OP_LOOKUPINO  = 0x00104,
		CEPH_MDS_OP_LOOKUPNAME = 0x00105,
	
		CEPH_MDS_OP_SETXATTR   = 0x01105,
		CEPH_MDS_OP_RMXATTR    = 0x01106,
		CEPH_MDS_OP_SETLAYOUT  = 0x01107,
		CEPH_MDS_OP_SETATTR    = 0x01108,
		CEPH_MDS_OP_SETFILELOCK= 0x01109,
		CEPH_MDS_OP_GETFILELOCK= 0x00110,
		CEPH_MDS_OP_SETDIRLAYOUT=0x0110a,
	
		CEPH_MDS_OP_MKNOD      = 0x01201,
		CEPH_MDS_OP_LINK       = 0x01202,
		CEPH_MDS_OP_UNLINK     = 0x01203,
		CEPH_MDS_OP_RENAME     = 0x01204,
		CEPH_MDS_OP_MKDIR      = 0x01220,
		CEPH_MDS_OP_RMDIR      = 0x01221,
		CEPH_MDS_OP_SYMLINK    = 0x01222,
	
		CEPH_MDS_OP_CREATE     = 0x01301,
		CEPH_MDS_OP_OPEN       = 0x00302,
		CEPH_MDS_OP_READDIR    = 0x00305,
	
		CEPH_MDS_OP_LOOKUPSNAP = 0x00400,
		CEPH_MDS_OP_MKSNAP     = 0x01400,
		CEPH_MDS_OP_RMSNAP     = 0x01401,
		CEPH_MDS_OP_LSSNAP     = 0x00402,
		CEPH_MDS_OP_RENAMESNAP = 0x01403,
	
		// internal op
		CEPH_MDS_OP_FRAGMENTDIR= 0x01500,
		CEPH_MDS_OP_EXPORTDIR  = 0x01501,
		CEPH_MDS_OP_FLUSH      = 0x01502,
		CEPH_MDS_OP_ENQUEUE_SCRUB  = 0x01503,
		CEPH_MDS_OP_REPAIR_FRAGSTATS = 0x01504,
		CEPH_MDS_OP_REPAIR_INODESTATS = 0x01505,
		CEPH_MDS_OP_UPGRADE_SNAPREALM = 0x01506
	};
	
	extern const char *ceph_mds_op_name(int op);
	
	#ifndef CEPH_SETATTR_MODE
	#define CEPH_SETATTR_MODE	(1 << 0)
	#define CEPH_SETATTR_UID	(1 << 1)
	#define CEPH_SETATTR_GID	(1 << 2)
	#define CEPH_SETATTR_MTIME	(1 << 3)
	#define CEPH_SETATTR_ATIME	(1 << 4)
	#define CEPH_SETATTR_SIZE	(1 << 5)
	#define CEPH_SETATTR_CTIME	(1 << 6)
	#define CEPH_SETATTR_MTIME_NOW	(1 << 7)
	#define CEPH_SETATTR_ATIME_NOW	(1 << 8)
	#define CEPH_SETATTR_BTIME	(1 << 9)
	#endif
	#define CEPH_SETATTR_KILL_SGUID	(1 << 10)
	
	/*
	 * open request flags
	 */
	#define CEPH_O_RDONLY          00000000
	#define CEPH_O_WRONLY          00000001
	#define CEPH_O_RDWR            00000002
	#define CEPH_O_CREAT           00000100
	#define CEPH_O_EXCL            00000200
	#define CEPH_O_TRUNC           00001000
	#define CEPH_O_LAZY            00020000
	#define CEPH_O_DIRECTORY       00200000
	#define CEPH_O_NOFOLLOW        00400000
	
	int ceph_flags_sys2wire(int flags);
	
	/*
	 * Ceph setxattr request flags.
	 */
	#define CEPH_XATTR_CREATE  (1 << 0)
	#define CEPH_XATTR_REPLACE (1 << 1)
	#define CEPH_XATTR_REMOVE  (1 << 31)
	
	/*
	 * readdir request flags;
	 */
	#define CEPH_READDIR_REPLY_BITFLAGS	(1<<0)
	
	/*
	 * readdir reply flags.
	 */
	#define CEPH_READDIR_FRAG_END		(1<<0)
	#define CEPH_READDIR_FRAG_COMPLETE	(1<<8)
	#define CEPH_READDIR_HASH_ORDER		(1<<9)
	#define CEPH_READDIR_OFFSET_HASH       (1<<10)
	
	/* Note that this is embedded wthin ceph_mds_request_head_legacy. */
	union ceph_mds_request_args_legacy {
		struct {
			__le32 mask;                 /* CEPH_CAP_* */
		} __attribute__ ((packed)) getattr;
		struct {
			__le32 mode;
			__le32 uid;
			__le32 gid;
			struct ceph_timespec mtime;
			struct ceph_timespec atime;
			__le64 size, old_size;       /* old_size needed by truncate */
			__le32 mask;                 /* CEPH_SETATTR_* */
		} __attribute__ ((packed)) setattr;
		struct {
			__le32 frag;                 /* which dir fragment */
			__le32 max_entries;          /* how many dentries to grab */
			__le32 max_bytes;
			__le16 flags;
	               __le32 offset_hash;
		} __attribute__ ((packed)) readdir;
		struct {
			__le32 mode;
			__le32 rdev;
		} __attribute__ ((packed)) mknod;
		struct {
			__le32 mode;
		} __attribute__ ((packed)) mkdir;
		struct {
			__le32 flags;
			__le32 mode;
			__le32 stripe_unit;          /* layout for newly created file */
			__le32 stripe_count;         /* ... */
			__le32 object_size;
			__le32 pool;                 /* if >= 0 and CREATEPOOLID feature */
			__le32 mask;                 /* CEPH_CAP_* */
			__le64 old_size;             /* if O_TRUNC */
		} __attribute__ ((packed)) open;
		struct {
			__le32 flags;
			__le32 osdmap_epoch; 	    /* use for set file/dir layout */
		} __attribute__ ((packed)) setxattr;
		struct {
			struct ceph_file_layout layout;
		} __attribute__ ((packed)) setlayout;
		struct {
			__u8 rule; /* currently fcntl or flock */
			__u8 type; /* shared, exclusive, remove*/
			__le64 owner; /* who requests/holds the lock */
			__le64 pid; /* process id requesting the lock */
			__le64 start; /* initial location to lock */
			__le64 length; /* num bytes to lock from start */
			__u8 wait; /* will caller wait for lock to become available? */
		} __attribute__ ((packed)) filelock_change;
	} __attribute__ ((packed));
	
	#define CEPH_MDS_FLAG_REPLAY        1  /* this is a replayed op */
	#define CEPH_MDS_FLAG_WANT_DENTRY   2  /* want dentry in reply */
	
	struct ceph_mds_request_head_legacy {
		__le64 oldest_client_tid;
		__le32 mdsmap_epoch;           /* on client */
		__le32 flags;                  /* CEPH_MDS_FLAG_* */
		__u8 num_retry, num_fwd;       /* count retry, fwd attempts */
		__le16 num_releases;           /* # include cap/lease release records */
		__le32 op;                     /* mds op code */
		__le32 caller_uid, caller_gid;
		__le64 ino;                    /* use this ino for openc, mkdir, mknod,
						  etc. (if replaying) */
		union ceph_mds_request_args_legacy args;
	} __attribute__ ((packed));
	
	/*
	 * Note that this is embedded wthin ceph_mds_request_head. Also, compatibility
	 * with the ceph_mds_request_args_legacy must be maintained!
	 */
	union ceph_mds_request_args {
		struct {
			__le32 mask;                 /* CEPH_CAP_* */
		} __attribute__ ((packed)) getattr;
		struct {
			__le32 mode;
			__le32 uid;
			__le32 gid;
			struct ceph_timespec mtime;
			struct ceph_timespec atime;
			__le64 size, old_size;       /* old_size needed by truncate */
			__le32 mask;                 /* CEPH_SETATTR_* */
			struct ceph_timespec btime;
		} __attribute__ ((packed)) setattr;
		struct {
			__le32 frag;                 /* which dir fragment */
			__le32 max_entries;          /* how many dentries to grab */
			__le32 max_bytes;
			__le16 flags;
	               __le32 offset_hash;
		} __attribute__ ((packed)) readdir;
		struct {
			__le32 mode;
			__le32 rdev;
		} __attribute__ ((packed)) mknod;
		struct {
			__le32 mode;
		} __attribute__ ((packed)) mkdir;
		struct {
			__le32 flags;
			__le32 mode;
			__le32 stripe_unit;          /* layout for newly created file */
			__le32 stripe_count;         /* ... */
			__le32 object_size;
			__le32 pool;                 /* if >= 0 and CREATEPOOLID feature */
			__le32 mask;                 /* CEPH_CAP_* */
			__le64 old_size;             /* if O_TRUNC */
		} __attribute__ ((packed)) open;
		struct {
			__le32 flags;
			__le32 osdmap_epoch; 	    /* use for set file/dir layout */
		} __attribute__ ((packed)) setxattr;
		struct {
			struct ceph_file_layout layout;
		} __attribute__ ((packed)) setlayout;
		struct {
			__u8 rule; /* currently fcntl or flock */
			__u8 type; /* shared, exclusive, remove*/
			__le64 owner; /* who requests/holds the lock */
			__le64 pid; /* process id requesting the lock */
			__le64 start; /* initial location to lock */
			__le64 length; /* num bytes to lock from start */
			__u8 wait; /* will caller wait for lock to become available? */
		} __attribute__ ((packed)) filelock_change;
		struct {
			__le32 mask;                 /* CEPH_CAP_* */
			__le64 snapid;
			__le64 parent;
			__le32 hash;
		} __attribute__ ((packed)) lookupino;
	} __attribute__ ((packed));
	
	#define CEPH_MDS_REQUEST_HEAD_VERSION	1
	
	/*
	 * Note that any change to this structure must ensure that it is compatible
	 * with ceph_mds_request_head_legacy.
	 */
	struct ceph_mds_request_head {

		__le16 version;

		__le64 oldest_client_tid;

		__le32 mdsmap_epoch;           /* on client */

		__le32 flags;                  /* CEPH_MDS_FLAG_* */

		__u8 num_retry, num_fwd;       /* count retry, fwd attempts */

		__le16 num_releases;           /* # include cap/lease release records */

		__le32 op;                     /* mds op code */

		__le32 caller_uid, caller_gid;

		__le64 ino;                    /* use this ino for openc, mkdir, mknod,
						  etc. (if replaying) */
		union ceph_mds_request_args args;
	} __attribute__ ((packed));
	
	/* cap/lease release record */
	struct ceph_mds_request_release {
		__le64 ino, cap_id;            /* ino and unique cap id */
		__le32 caps, wanted;           /* new issued, wanted */
		__le32 seq, issue_seq, mseq;
		__le32 dname_seq;              /* if releasing a dentry lease, a */
		__le32 dname_len;              /* string follows. */
	} __attribute__ ((packed));
	
	static inline void
	copy_from_legacy_head(struct ceph_mds_request_head *head,
				struct ceph_mds_request_head_legacy *legacy)
	{
		struct ceph_mds_request_head_legacy *embedded_legacy =
			(struct ceph_mds_request_head_legacy *)&head->oldest_client_tid;
		*embedded_legacy = *legacy;
	}
	
	static inline void
	copy_to_legacy_head(struct ceph_mds_request_head_legacy *legacy,
				struct ceph_mds_request_head *head)
	{
		struct ceph_mds_request_head_legacy *embedded_legacy =
			(struct ceph_mds_request_head_legacy *)&head->oldest_client_tid;
		*legacy = *embedded_legacy;
	}
	
	/* client reply */
	struct ceph_mds_reply_head {
		__le32 op;
		__le32 result;
		__le32 mdsmap_epoch;
		__u8 safe;                     /* true if committed to disk */
		__u8 is_dentry, is_target;     /* true if dentry, target inode records
						  are included with reply */
	} __attribute__ ((packed));
	
	/* one for each node split */
	struct ceph_frag_tree_split {
		__le32 frag;                   /* this frag splits... */
		__le32 by;                     /* ...by this many bits */
	} __attribute__ ((packed));
	
	struct ceph_frag_tree_head {
		__le32 nsplits;                /* num ceph_frag_tree_split records */
		struct ceph_frag_tree_split splits[];
	} __attribute__ ((packed));
	
	/* capability issue, for bundling with mds reply */
	struct ceph_mds_reply_cap {
		__le32 caps, wanted;           /* caps issued, wanted */
		__le64 cap_id;
		__le32 seq, mseq;
		__le64 realm;                  /* snap realm */
		__u8 flags;                    /* CEPH_CAP_FLAG_* */
	} __attribute__ ((packed));
	
	#define CEPH_CAP_FLAG_AUTH	(1 << 0)	/* cap is issued by auth mds */
	#define CEPH_CAP_FLAG_RELEASE	(1 << 1)        /* ask client to release the cap */
	
	/* reply_lease follows dname, and reply_inode */
	struct ceph_mds_reply_lease {
		__le16 mask;            /* lease type(s) */
		__le32 duration_ms;     /* lease duration */
		__le32 seq;
	} __attribute__ ((packed));
	
	struct ceph_mds_reply_dirfrag {
		__le32 frag;            /* fragment */
		__le32 auth;            /* auth mds, if this is a delegation point */
		__le32 ndist;           /* number of mds' this is replicated on */
		__le32 dist[];
	} __attribute__ ((packed));
	
	#define CEPH_LOCK_FCNTL		1
	#define CEPH_LOCK_FLOCK		2
	#define CEPH_LOCK_FCNTL_INTR	3
	#define CEPH_LOCK_FLOCK_INTR	4
	
	#define CEPH_LOCK_SHARED   1
	#define CEPH_LOCK_EXCL     2
	#define CEPH_LOCK_UNLOCK   4
	
	struct ceph_filelock {
		__le64 start;/* file offset to start lock at */
		__le64 length; /* num bytes to lock; 0 for all following start */
		__le64 client; /* which client holds the lock */
		__le64 owner; /* who requests/holds the lock */
		__le64 pid; /* process id holding the lock on the client */
		__u8 type; /* shared lock, exclusive lock, or unlock */
	} __attribute__ ((packed));
	
	
	/* file access modes */
	#define CEPH_FILE_MODE_PIN        0
	#define CEPH_FILE_MODE_RD         1
	#define CEPH_FILE_MODE_WR         2
	#define CEPH_FILE_MODE_RDWR       3  /* RD | WR */
	#define CEPH_FILE_MODE_LAZY       4  /* lazy io */
	#define CEPH_FILE_MODE_NUM        8  /* bc these are bit fields.. mostly */
	
	int ceph_flags_to_mode(int flags);
	
	/* inline data state */
	#define CEPH_INLINE_NONE	((__u64)-1)
	#define CEPH_INLINE_MAX_SIZE	CEPH_MIN_STRIPE_UNIT
	
	/* capability bits */
	#define CEPH_CAP_PIN         1  /* no specific capabilities beyond the pin */
	
	/* generic cap bits */
	/* note: these definitions are duplicated in mds/locks.c */
	#define CEPH_CAP_GSHARED     1  /* client can reads */
	#define CEPH_CAP_GEXCL       2  /* client can read and update */
	#define CEPH_CAP_GCACHE      4  /* (file) client can cache reads */
	#define CEPH_CAP_GRD         8  /* (file) client can read */
	#define CEPH_CAP_GWR        16  /* (file) client can write */
	#define CEPH_CAP_GBUFFER    32  /* (file) client can buffer writes */
	#define CEPH_CAP_GWREXTEND  64  /* (file) client can extend EOF */
	#define CEPH_CAP_GLAZYIO   128  /* (file) client can perform lazy io */
	
	#define CEPH_CAP_SIMPLE_BITS  2
	#define CEPH_CAP_FILE_BITS    8
	
	/* per-lock shift */
	#define CEPH_CAP_SAUTH      2
	#define CEPH_CAP_SLINK      4
	#define CEPH_CAP_SXATTR     6
	#define CEPH_CAP_SFILE      8
	
	/* composed values */
	#define CEPH_CAP_AUTH_SHARED  (CEPH_CAP_GSHARED  << CEPH_CAP_SAUTH)
	#define CEPH_CAP_AUTH_EXCL     (CEPH_CAP_GEXCL     << CEPH_CAP_SAUTH)
	#define CEPH_CAP_LINK_SHARED  (CEPH_CAP_GSHARED  << CEPH_CAP_SLINK)
	#define CEPH_CAP_LINK_EXCL     (CEPH_CAP_GEXCL     << CEPH_CAP_SLINK)
	#define CEPH_CAP_XATTR_SHARED (CEPH_CAP_GSHARED  << CEPH_CAP_SXATTR)
	#define CEPH_CAP_XATTR_EXCL    (CEPH_CAP_GEXCL     << CEPH_CAP_SXATTR)
	#define CEPH_CAP_FILE(x)    (x << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_SHARED   (CEPH_CAP_GSHARED   << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_EXCL     (CEPH_CAP_GEXCL     << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_CACHE    (CEPH_CAP_GCACHE    << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_RD       (CEPH_CAP_GRD       << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_WR       (CEPH_CAP_GWR       << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_BUFFER   (CEPH_CAP_GBUFFER   << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_WREXTEND (CEPH_CAP_GWREXTEND << CEPH_CAP_SFILE)
	#define CEPH_CAP_FILE_LAZYIO   (CEPH_CAP_GLAZYIO   << CEPH_CAP_SFILE)
	
	/* cap masks (for getattr) */
	#define CEPH_STAT_CAP_INODE    CEPH_CAP_PIN
	#define CEPH_STAT_CAP_TYPE     CEPH_CAP_PIN  /* mode >> 12 */
	#define CEPH_STAT_CAP_SYMLINK  CEPH_CAP_PIN
	#define CEPH_STAT_CAP_UID      CEPH_CAP_AUTH_SHARED
	#define CEPH_STAT_CAP_GID      CEPH_CAP_AUTH_SHARED
	#define CEPH_STAT_CAP_MODE     CEPH_CAP_AUTH_SHARED
	#define CEPH_STAT_CAP_NLINK    CEPH_CAP_LINK_SHARED
	#define CEPH_STAT_CAP_LAYOUT   CEPH_CAP_FILE_SHARED
	#define CEPH_STAT_CAP_MTIME    CEPH_CAP_FILE_SHARED
	#define CEPH_STAT_CAP_SIZE     CEPH_CAP_FILE_SHARED
	#define CEPH_STAT_CAP_ATIME    CEPH_CAP_FILE_SHARED  /* fixme */
	#define CEPH_STAT_CAP_XATTR    CEPH_CAP_XATTR_SHARED
	#define CEPH_STAT_CAP_INODE_ALL (CEPH_CAP_PIN |			\
					 CEPH_CAP_AUTH_SHARED |	\
					 CEPH_CAP_LINK_SHARED |	\
					 CEPH_CAP_FILE_SHARED |	\
					 CEPH_CAP_XATTR_SHARED)
	#define CEPH_STAT_CAP_INLINE_DATA (CEPH_CAP_FILE_SHARED | \
					   CEPH_CAP_FILE_RD)
	#define CEPH_STAT_RSTAT        CEPH_CAP_FILE_WREXTEND
	
	#define CEPH_CAP_ANY_SHARED (CEPH_CAP_AUTH_SHARED |			\
				      CEPH_CAP_LINK_SHARED |			\
				      CEPH_CAP_XATTR_SHARED |			\
				      CEPH_CAP_FILE_SHARED)
	#define CEPH_CAP_ANY_RD   (CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_RD |	\
				   CEPH_CAP_FILE_CACHE)
	
	#define CEPH_CAP_ANY_EXCL (CEPH_CAP_AUTH_EXCL |		\
				   CEPH_CAP_LINK_EXCL |		\
				   CEPH_CAP_XATTR_EXCL |	\
				   CEPH_CAP_FILE_EXCL)
	#define CEPH_CAP_ANY_FILE_RD (CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE | \
	                              CEPH_CAP_FILE_SHARED)
	#define CEPH_CAP_ANY_FILE_WR (CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER |	\
				      CEPH_CAP_FILE_EXCL)
	#define CEPH_CAP_ANY_WR   (CEPH_CAP_ANY_EXCL | CEPH_CAP_ANY_FILE_WR)
	#define CEPH_CAP_ANY      (CEPH_CAP_ANY_RD | CEPH_CAP_ANY_EXCL | \
				   CEPH_CAP_ANY_FILE_WR | CEPH_CAP_FILE_LAZYIO | \
				   CEPH_CAP_PIN)
	
	#define CEPH_CAP_LOCKS (CEPH_LOCK_IFILE | CEPH_LOCK_IAUTH | CEPH_LOCK_ILINK | \
				CEPH_LOCK_IXATTR)
	
	int ceph_caps_for_mode(int mode);
	
	enum {
		CEPH_CAP_OP_GRANT,         /* mds->client grant */
		CEPH_CAP_OP_REVOKE,        /* mds->client revoke */
		CEPH_CAP_OP_TRUNC,         /* mds->client trunc notify */
		CEPH_CAP_OP_EXPORT,        /* mds has exported the cap */
		CEPH_CAP_OP_IMPORT,        /* mds has imported the cap */
		CEPH_CAP_OP_UPDATE,        /* client->mds update */
		CEPH_CAP_OP_DROP,          /* client->mds drop cap bits */
		CEPH_CAP_OP_FLUSH,         /* client->mds cap writeback */
		CEPH_CAP_OP_FLUSH_ACK,     /* mds->client flushed */
		CEPH_CAP_OP_FLUSHSNAP,     /* client->mds flush snapped metadata */
		CEPH_CAP_OP_FLUSHSNAP_ACK, /* mds->client flushed snapped metadata */
		CEPH_CAP_OP_RELEASE,       /* client->mds release (clean) cap */
		CEPH_CAP_OP_RENEW,         /* client->mds renewal request */
	};
	
	extern const char *ceph_cap_op_name(int op);
	
	/* extra info for cap import/export */
	struct ceph_mds_cap_peer {
		__le64 cap_id;
		__le32 seq;
		__le32 mseq;
		__le32 mds;
		__u8   flags;
	} __attribute__ ((packed));
	
	/*
	 * caps message, used for capability callbacks, acks, requests, etc.
	 */
	struct ceph_mds_caps_head {
		__le32 op;                  /* CEPH_CAP_OP_* */
		__le64 ino, realm;
		__le64 cap_id;
		__le32 seq, issue_seq;
		__le32 caps, wanted, dirty; /* latest issued/wanted/dirty */
		__le32 migrate_seq;
		__le64 snap_follows;
		__le32 snap_trace_len;
	
		/* authlock */
		__le32 uid, gid, mode;
	
		/* linklock */
		__le32 nlink;
	
		/* xattrlock */
		__le32 xattr_len;
		__le64 xattr_version;
	} __attribute__ ((packed));
	
	struct ceph_mds_caps_body_legacy {
		union {
			/* all except export */
			struct {
				/* filelock */
				__le64 size, max_size, truncate_size;
				__le32 truncate_seq;
				struct ceph_timespec mtime, atime, ctime;
				struct ceph_file_layout layout;
				__le32 time_warp_seq;
			} __attribute__ ((packed));
			/* export message */
			struct ceph_mds_cap_peer peer;
		} __attribute__ ((packed));
	} __attribute__ ((packed));
	
	/* cap release msg head */
	struct ceph_mds_cap_release {
		__le32 num;                /* number of cap_items that follow */
	} __attribute__ ((packed));
	
	struct ceph_mds_cap_item {
		__le64 ino;
		__le64 cap_id;
		__le32 migrate_seq, seq;
	} __attribute__ ((packed));
	
	#define CEPH_MDS_LEASE_REVOKE           1  /*    mds  -> client */
	#define CEPH_MDS_LEASE_RELEASE          2  /* client  -> mds    */
	#define CEPH_MDS_LEASE_RENEW            3  /* client <-> mds    */
	#define CEPH_MDS_LEASE_REVOKE_ACK       4  /* client  -> mds    */
	
	extern const char *ceph_lease_op_name(int o);
	
	/* lease msg header */
	struct ceph_mds_lease {
		__u8 action;            /* CEPH_MDS_LEASE_* */
		__le16 mask;            /* which lease */
		__le64 ino;
		__le64 first, last;     /* snap range */
		__le32 seq;
		__le32 duration_ms;     /* duration of renewal */
	} __attribute__ ((packed));
	/* followed by a __le32+string for dname */
	
	/* client reconnect */
	struct ceph_mds_cap_reconnect {
		__le64 cap_id;
		__le32 wanted;
		__le32 issued;
		__le64 snaprealm;
		__le64 pathbase;        /* base ino for our path to this ino */
		__le32 flock_len;       /* size of flock state blob, if any */
	} __attribute__ ((packed));
	/* followed by flock blob */
	
	struct ceph_mds_cap_reconnect_v1 {
		__le64 cap_id;
		__le32 wanted;
		__le32 issued;
		__le64 size;
		struct ceph_timespec mtime, atime;
		__le64 snaprealm;
		__le64 pathbase;        /* base ino for our path to this ino */
	} __attribute__ ((packed));
	
	struct ceph_mds_snaprealm_reconnect {
		__le64 ino;     /* snap realm base */
		__le64 seq;     /* snap seq for this snap realm */
		__le64 parent;  /* parent realm */
	} __attribute__ ((packed));
	
	/*
	 * snaps
	 */
	enum {
		CEPH_SNAP_OP_UPDATE,  /* CREATE or DESTROY */
		CEPH_SNAP_OP_CREATE,
		CEPH_SNAP_OP_DESTROY,
		CEPH_SNAP_OP_SPLIT,
	};
	
	extern const char *ceph_snap_op_name(int o);
	
	/* snap msg header */
	struct ceph_mds_snap_head {
		__le32 op;                /* CEPH_SNAP_OP_* */
		__le64 split;             /* ino to split off, if any */
		__le32 num_split_inos;    /* # inos belonging to new child realm */
		__le32 num_split_realms;  /* # child realms udner new child realm */
		__le32 trace_len;         /* size of snap trace blob */
	} __attribute__ ((packed));
	/* followed by split ino list, then split realms, then the trace blob */
	
	/*
	 * encode info about a snaprealm, as viewed by a client
	 */
	struct ceph_mds_snap_realm {
		__le64 ino;           /* ino */
		__le64 created;       /* snap: when created */
		__le64 parent;        /* ino: parent realm */
		__le64 parent_since;  /* snap: same parent since */
		__le64 seq;           /* snap: version */
		__le32 num_snaps;
		__le32 num_prior_parent_snaps;
	} __attribute__ ((packed));
	/* followed by my snap list, then prior parent snap list */
	
	#ifndef __KERNEL__
	#undef __le16
	#undef __le32
	#undef __le64
	#endif
	
	#endif