[deliverable/linux.git] / fs / ceph / mds_client.h

#ifndef _FS_CEPH_MDS_CLIENT_H
#define _FS_CEPH_MDS_CLIENT_H

#include <linux/completion.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>

#include <linux/ceph/types.h>
#include <linux/ceph/messenger.h>
#include <linux/ceph/mdsmap.h>

/*
 * Some lock dependencies:
 *
 * session->s_mutex
 *         mdsc->mutex
 *
 *         mdsc->snap_rwsem
 *
 *         inode->i_lock
 *                 mdsc->snap_flush_lock
 *                 mdsc->cap_delay_lock
 *
 */

struct ceph_fs_client;
struct ceph_cap;

/*
 * parsed info about a single inode.  pointers are into the encoded
 * on-wire structures within the mds reply message payload.
 */
struct ceph_mds_reply_info_in {
	struct ceph_mds_reply_inode *in;
	struct ceph_dir_layout dir_layout;
	u32 symlink_len;
	char *symlink;
	u32 xattr_len;
	char *xattr_data;
};

/*
 * parsed info about an mds reply, including information about
 * either: 1) the target inode and/or its parent directory and dentry,
 * and directory contents (for readdir results), or
 * 2) the file range lock info (for fcntl F_GETLK results).
 */
struct ceph_mds_reply_info_parsed {
	struct ceph_mds_reply_head    *head;

	/* trace */
	struct ceph_mds_reply_info_in diri, targeti;
	struct ceph_mds_reply_dirfrag *dirfrag;
	char                          *dname;
	u32                           dname_len;
	struct ceph_mds_reply_lease   *dlease;

	/* extra */
	union {
		/* for fcntl F_GETLK results */
		struct ceph_filelock *filelock_reply;

		/* for readdir results */
		struct {
			struct ceph_mds_reply_dirfrag *dir_dir;
			int                           dir_nr;
			char                          **dir_dname;
			u32                           *dir_dname_len;
			struct ceph_mds_reply_lease   **dir_dlease;
			struct ceph_mds_reply_info_in *dir_in;
			u8                            dir_complete, dir_end;
		};
	};

	/* encoded blob describing snapshot contexts for certain
	   operations (e.g., open) */
	void *snapblob;
	int snapblob_len;
};


/*
 * cap releases are batched and sent to the MDS en masse.
 */
#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE -			\
				sizeof(struct ceph_mds_cap_release)) /	\
			       sizeof(struct ceph_mds_cap_item))


/*
 * state associated with each MDS<->client session
 */
enum {
	CEPH_MDS_SESSION_NEW = 1,
	CEPH_MDS_SESSION_OPENING = 2,
	CEPH_MDS_SESSION_OPEN = 3,
	CEPH_MDS_SESSION_HUNG = 4,
	CEPH_MDS_SESSION_CLOSING = 5,
	CEPH_MDS_SESSION_RESTARTING = 6,
	CEPH_MDS_SESSION_RECONNECTING = 7,
};

struct ceph_mds_session {
	struct ceph_mds_client *s_mdsc;
	int               s_mds;
	int               s_state;
	unsigned long     s_ttl;      /* time until mds kills us */
	u64               s_seq;      /* incoming msg seq # */
	struct mutex      s_mutex;    /* serialize session messages */

	struct ceph_connection s_con;

	struct ceph_authorizer *s_authorizer;
	void             *s_authorizer_buf, *s_authorizer_reply_buf;
	size_t            s_authorizer_buf_len, s_authorizer_reply_buf_len;

	/* protected by s_cap_lock */
	spinlock_t        s_cap_lock;
	u32               s_cap_gen;  /* inc each time we get mds stale msg */
	unsigned long     s_cap_ttl;  /* when session caps expire */
	struct list_head  s_caps;     /* all caps issued by this session */
	int               s_nr_caps, s_trim_caps;
	int               s_num_cap_releases;
	struct list_head  s_cap_releases; /* waiting cap_release messages */
	struct list_head  s_cap_releases_done; /* ready to send */
	struct ceph_cap  *s_cap_iterator;

	/* protected by mutex */
	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
	struct list_head  s_cap_snaps_flushing;
	unsigned long     s_renew_requested; /* last time we sent a renew req */
	u64               s_renew_seq;

	atomic_t          s_ref;
	struct list_head  s_waiting;  /* waiting requests */
	struct list_head  s_unsafe;   /* unsafe requests */
};

/*
 * modes of choosing which MDS to send a request to
 */
enum {
	USE_ANY_MDS,
	USE_RANDOM_MDS,
	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
};

struct ceph_mds_request;
struct ceph_mds_client;

/*
 * request completion callback
 */
typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
					     struct ceph_mds_request *req);

/*
 * an in-flight mds request
 */
struct ceph_mds_request {
	u64 r_tid;                   /* transaction id */
	struct rb_node r_node;
	struct ceph_mds_client *r_mdsc;

	int r_op;                    /* mds op code */

	/* operation on what? */
	struct inode *r_inode;              /* arg1 */
	struct dentry *r_dentry;            /* arg1 */
	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
	char *r_path1, *r_path2;
	struct ceph_vino r_ino1, r_ino2;

	struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
	struct inode *r_target_inode;       /* resulting inode */

	struct mutex r_fill_mutex;

	union ceph_mds_request_args r_args;
	int r_fmode;        /* file mode, if expecting cap */
	uid_t r_uid;
	gid_t r_gid;

	/* for choosing which mds to send this request to */
	int r_direct_mode;
	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
	bool r_direct_is_hash;  /* true if r_direct_hash is valid */

	/* data payload is used for xattr ops */
	struct page **r_pages;
	int r_num_pages;
	int r_data_len;

	/* what caps shall we drop? */
	int r_inode_drop, r_inode_unless;
	int r_dentry_drop, r_dentry_unless;
	int r_old_dentry_drop, r_old_dentry_unless;
	struct inode *r_old_inode;
	int r_old_inode_drop, r_old_inode_unless;

	struct ceph_msg  *r_request;  /* original request */
	int r_request_release_offset;
	struct ceph_msg  *r_reply;
	struct ceph_mds_reply_info_parsed r_reply_info;
	int r_err;
	bool r_aborted;

	unsigned long r_timeout;  /* optional.  jiffies */
	unsigned long r_started;  /* start time to measure timeout against */
	unsigned long r_request_started; /* start time for mds request only,
					    used to measure lease durations */

	/* link unsafe requests to parent directory, for fsync */
	struct inode	*r_unsafe_dir;
	struct list_head r_unsafe_dir_item;

	struct ceph_mds_session *r_session;

	int               r_attempts;   /* resend attempts */
	int               r_num_fwd;    /* number of forward attempts */
	int               r_resend_mds; /* mds to resend to next, if any*/
	u32               r_sent_on_mseq; /* cap mseq request was sent at*/

	struct kref       r_kref;
	struct list_head  r_wait;
	struct completion r_completion;
	struct completion r_safe_completion;
	ceph_mds_request_callback_t r_callback;
	struct list_head  r_unsafe_item;  /* per-session unsafe list item */
	bool		  r_got_unsafe, r_got_safe, r_got_result;

	bool              r_did_prepopulate;
	u32               r_readdir_offset;

	struct ceph_cap_reservation r_caps_reservation;
	int r_num_caps;
};

/*
 * mds client state
 */
struct ceph_mds_client {
	struct ceph_fs_client  *fsc;
	struct mutex            mutex;         /* all nested structures */

	struct ceph_mdsmap      *mdsmap;
	struct completion       safe_umount_waiters;
	wait_queue_head_t       session_close_wq;
	struct list_head        waiting_for_map;

	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
	int                     max_sessions;  /* len of s_mds_sessions */
	int                     stopping;      /* true if shutting down */

	/*
	 * snap_rwsem will cover cap linkage into snaprealms, and
	 * realm snap contexts.  (later, we can do per-realm snap
	 * contexts locks..)  the empty list contains realms with no
	 * references (implying they contain no inodes with caps) that
	 * should be destroyed.
	 */
	struct rw_semaphore     snap_rwsem;
	struct rb_root          snap_realms;
	struct list_head        snap_empty;
	spinlock_t              snap_empty_lock;  /* protect snap_empty */

	u64                    last_tid;      /* most recent mds request */
	struct rb_root         request_tree;  /* pending mds requests */
	struct delayed_work    delayed_work;  /* delayed work */
	unsigned long    last_renew_caps;  /* last time we renewed our caps */
	struct list_head cap_delay_list;   /* caps with delayed release */
	spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
	spinlock_t       snap_flush_lock;

	u64               cap_flush_seq;
	struct list_head  cap_dirty;        /* inodes with dirty caps */
	struct list_head  cap_dirty_migrating; /* ...that are migration... */
	int               num_cap_flushing; /* # caps we are flushing */
	spinlock_t        cap_dirty_lock;   /* protects above items */
	wait_queue_head_t cap_flushing_wq;

	/*
	 * Cap reservations
	 *
	 * Maintain a global pool of preallocated struct ceph_caps, referenced
	 * by struct ceph_caps_reservations.  This ensures that we preallocate
	 * memory needed to successfully process an MDS response.  (If an MDS
	 * sends us cap information and we fail to process it, we will have
	 * problems due to the client and MDS being out of sync.)
	 *
	 * Reservations are 'owned' by a ceph_cap_reservation context.
	 */
	spinlock_t	caps_list_lock;
	struct		list_head caps_list; /* unused (reserved or
						unreserved) */
	int		caps_total_count;    /* total caps allocated */
	int		caps_use_count;      /* in use */
	int		caps_reserve_count;  /* unused, reserved */
	int		caps_avail_count;    /* unused, unreserved */
	int		caps_min_count;      /* keep at least this many
						(unreserved) */
	spinlock_t	  dentry_lru_lock;
	struct list_head  dentry_lru;
	int		  num_dentry;
};

extern const char *ceph_mds_op_name(int op);

extern struct ceph_mds_session *
__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);

static inline struct ceph_mds_session *
ceph_get_mds_session(struct ceph_mds_session *s)
{
	atomic_inc(&s->s_ref);
	return s;
}

extern void ceph_put_mds_session(struct ceph_mds_session *s);

extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
			     struct ceph_msg *msg, int mds);

extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);

extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);

extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
				    struct inode *inode,
				    struct dentry *dn);

extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);

extern struct ceph_mds_request *
ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
				     struct ceph_mds_request *req);
extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
				struct inode *dir,
				struct ceph_mds_request *req);
static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
{
	kref_get(&req->r_kref);
}
extern void ceph_mdsc_release_request(struct kref *kref);
static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
{
	kref_put(&req->r_kref, ceph_mdsc_release_request);
}

extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
				 struct ceph_mds_session *session);
extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
				   struct ceph_mds_session *session);

extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);

extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
				  int stop_on_nosnap);

extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
				     struct inode *inode,
				     struct dentry *dentry, char action,
				     u32 seq);

extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
				 struct ceph_msg *msg);

extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
					  struct ceph_mds_session *session);

#endif
Commit	Line	Data
2f2dc053 SW	1	#ifndef _FS_CEPH_MDS_CLIENT_H
	2	#define _FS_CEPH_MDS_CLIENT_H
	3
	4	#include <linux/completion.h>
153c8e6b	5	#include <linux/kref.h>
2f2dc053 SW	6	#include <linux/list.h>
2f2dc053 SW	7	#include <linux/mutex.h>
44ca18f2	8	#include <linux/rbtree.h>
2f2dc053 SW	9	#include <linux/spinlock.h>
2f2dc053 SW	10
3d14c5d2 YS	11	#include <linux/ceph/types.h>
	12	#include <linux/ceph/messenger.h>
	13	#include <linux/ceph/mdsmap.h>
2f2dc053 SW	14
	15	/*
	16	* Some lock dependencies:
	17	*
	18	* session->s_mutex
	19	* mdsc->mutex
	20	*
	21	* mdsc->snap_rwsem
	22	*
	23	* inode->i_lock
	24	* mdsc->snap_flush_lock
	25	* mdsc->cap_delay_lock
	26	*
	27	*/
	28
3d14c5d2	29	struct ceph_fs_client;
2f2dc053 SW	30	struct ceph_cap;
	31
	32	/*
	33	* parsed info about a single inode. pointers are into the encoded
	34	* on-wire structures within the mds reply message payload.
	35	*/
	36	struct ceph_mds_reply_info_in {
	37	struct ceph_mds_reply_inode *in;
14303d20	38	struct ceph_dir_layout dir_layout;
2f2dc053 SW	39	u32 symlink_len;
	40	char *symlink;
	41	u32 xattr_len;
	42	char *xattr_data;
	43	};
	44
	45	/*
25933abd HS	46	* parsed info about an mds reply, including information about
	47	* either: 1) the target inode and/or its parent directory and dentry,
	48	* and directory contents (for readdir results), or
	49	* 2) the file range lock info (for fcntl F_GETLK results).
2f2dc053 SW	50	*/
	51	struct ceph_mds_reply_info_parsed {
	52	struct ceph_mds_reply_head *head;
	53
25933abd	54	/* trace */
2f2dc053 SW	55	struct ceph_mds_reply_info_in diri, targeti;
	56	struct ceph_mds_reply_dirfrag *dirfrag;
	57	char *dname;
	58	u32 dname_len;
	59	struct ceph_mds_reply_lease *dlease;
	60
25933abd HS	61	/* extra */
	62	union {
	63	/* for fcntl F_GETLK results */
	64	struct ceph_filelock *filelock_reply;
	65
	66	/* for readdir results */
	67	struct {
	68	struct ceph_mds_reply_dirfrag *dir_dir;
	69	int dir_nr;
	70	char **dir_dname;
	71	u32 *dir_dname_len;
	72	struct ceph_mds_reply_lease **dir_dlease;
	73	struct ceph_mds_reply_info_in *dir_in;
	74	u8 dir_complete, dir_end;
	75	};
	76	};
2f2dc053 SW	77
	78	/* encoded blob describing snapshot contexts for certain
	79	operations (e.g., open) */
	80	void *snapblob;
	81	int snapblob_len;
	82	};
	83
	84
	85	/*
	86	* cap releases are batched and sent to the MDS en masse.
	87	*/
	88	#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \
	89	sizeof(struct ceph_mds_cap_release)) / \
	90	sizeof(struct ceph_mds_cap_item))
	91
	92
	93	/*
	94	* state associated with each MDS<->client session
	95	*/
	96	enum {
	97	CEPH_MDS_SESSION_NEW = 1,
	98	CEPH_MDS_SESSION_OPENING = 2,
	99	CEPH_MDS_SESSION_OPEN = 3,
	100	CEPH_MDS_SESSION_HUNG = 4,
	101	CEPH_MDS_SESSION_CLOSING = 5,
	102	CEPH_MDS_SESSION_RESTARTING = 6,
	103	CEPH_MDS_SESSION_RECONNECTING = 7,
	104	};
	105
	106	struct ceph_mds_session {
	107	struct ceph_mds_client *s_mdsc;
	108	int s_mds;
	109	int s_state;
	110	unsigned long s_ttl; /* time until mds kills us */
	111	u64 s_seq; /* incoming msg seq # */
	112	struct mutex s_mutex; /* serialize session messages */
	113
	114	struct ceph_connection s_con;
	115
4e7a5dcd SW	116	struct ceph_authorizer *s_authorizer;
	117	void s_authorizer_buf, s_authorizer_reply_buf;
	118	size_t s_authorizer_buf_len, s_authorizer_reply_buf_len;
	119
2f2dc053 SW	120	/* protected by s_cap_lock */
	121	spinlock_t s_cap_lock;
	122	u32 s_cap_gen; /* inc each time we get mds stale msg */
	123	unsigned long s_cap_ttl; /* when session caps expire */
	124	struct list_head s_caps; /* all caps issued by this session */
	125	int s_nr_caps, s_trim_caps;
	126	int s_num_cap_releases;
	127	struct list_head s_cap_releases; /* waiting cap_release messages */
	128	struct list_head s_cap_releases_done; /* ready to send */
7c1332b8	129	struct ceph_cap *s_cap_iterator;
2f2dc053 SW	130
	131	/* protected by mutex */
	132	struct list_head s_cap_flushing; /* inodes w/ flushing caps */
	133	struct list_head s_cap_snaps_flushing;
	134	unsigned long s_renew_requested; /* last time we sent a renew req */
	135	u64 s_renew_seq;
	136
	137	atomic_t s_ref;
	138	struct list_head s_waiting; /* waiting requests */
	139	struct list_head s_unsafe; /* unsafe requests */
	140	};
	141
	142	/*
	143	* modes of choosing which MDS to send a request to
	144	*/
	145	enum {
	146	USE_ANY_MDS,
	147	USE_RANDOM_MDS,
	148	USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
	149	};
	150
	151	struct ceph_mds_request;
	152	struct ceph_mds_client;
	153
	154	/*
	155	* request completion callback
	156	*/
	157	typedef void (ceph_mds_request_callback_t) (struct ceph_mds_client mdsc,
	158	struct ceph_mds_request *req);
	159
	160	/*
	161	* an in-flight mds request
	162	*/
	163	struct ceph_mds_request {
	164	u64 r_tid; /* transaction id */
44ca18f2	165	struct rb_node r_node;
37151668	166	struct ceph_mds_client *r_mdsc;
2f2dc053 SW	167
2f2dc053 SW	168	int r_op; /* mds op code */
2f2dc053 SW	169
	170	/* operation on what? */
	171	struct inode r_inode; / arg1 */
	172	struct dentry r_dentry; / arg1 */
	173	struct dentry r_old_dentry; / arg2: rename from or link from */
41b02e1f	174	struct inode r_old_dentry_dir; / arg2: old dentry's parent dir */
2f2dc053 SW	175	char r_path1, r_path2;
	176	struct ceph_vino r_ino1, r_ino2;
	177
	178	struct inode r_locked_dir; / dir (if any) i_mutex locked by vfs */
	179	struct inode r_target_inode; / resulting inode */
	180
b4556396 SW	181	struct mutex r_fill_mutex;
b4556396 SW	182
2f2dc053 SW	183	union ceph_mds_request_args r_args;
2f2dc053 SW	184	int r_fmode; /* file mode, if expecting cap */
cb4276cc SW	185	uid_t r_uid;
cb4276cc SW	186	gid_t r_gid;
2f2dc053 SW	187
	188	/* for choosing which mds to send this request to */
	189	int r_direct_mode;
	190	u32 r_direct_hash; /* choose dir frag based on this dentry hash */
	191	bool r_direct_is_hash; /* true if r_direct_hash is valid */
	192
	193	/* data payload is used for xattr ops */
	194	struct page **r_pages;
	195	int r_num_pages;
	196	int r_data_len;
	197
	198	/* what caps shall we drop? */
	199	int r_inode_drop, r_inode_unless;
	200	int r_dentry_drop, r_dentry_unless;
	201	int r_old_dentry_drop, r_old_dentry_unless;
	202	struct inode *r_old_inode;
	203	int r_old_inode_drop, r_old_inode_unless;
	204
	205	struct ceph_msg r_request; / original request */
e979cf50	206	int r_request_release_offset;
2f2dc053 SW	207	struct ceph_msg *r_reply;
	208	struct ceph_mds_reply_info_parsed r_reply_info;
	209	int r_err;
5b1daecd	210	bool r_aborted;
2f2dc053 SW	211
	212	unsigned long r_timeout; /* optional. jiffies */
	213	unsigned long r_started; /* start time to measure timeout against */
	214	unsigned long r_request_started; /* start time for mds request only,
	215	used to measure lease durations */
	216
	217	/* link unsafe requests to parent directory, for fsync */
	218	struct inode *r_unsafe_dir;
	219	struct list_head r_unsafe_dir_item;
	220
	221	struct ceph_mds_session *r_session;
	222
	223	int r_attempts; /* resend attempts */
	224	int r_num_fwd; /* number of forward attempts */
2f2dc053	225	int r_resend_mds; /* mds to resend to next, if any*/
e55b71f8	226	u32 r_sent_on_mseq; /* cap mseq request was sent at*/
2f2dc053	227
153c8e6b	228	struct kref r_kref;
2f2dc053 SW	229	struct list_head r_wait;
	230	struct completion r_completion;
	231	struct completion r_safe_completion;
	232	ceph_mds_request_callback_t r_callback;
	233	struct list_head r_unsafe_item; /* per-session unsafe list item */
e1518c7c	234	bool r_got_unsafe, r_got_safe, r_got_result;
2f2dc053 SW	235
	236	bool r_did_prepopulate;
	237	u32 r_readdir_offset;
	238
	239	struct ceph_cap_reservation r_caps_reservation;
	240	int r_num_caps;
	241	};
	242
	243	/*
	244	* mds client state
	245	*/
	246	struct ceph_mds_client {
3d14c5d2	247	struct ceph_fs_client *fsc;
2f2dc053 SW	248	struct mutex mutex; /* all nested structures */
	249
	250	struct ceph_mdsmap *mdsmap;
f3c60c59 SW	251	struct completion safe_umount_waiters;
f3c60c59 SW	252	wait_queue_head_t session_close_wq;
2f2dc053 SW	253	struct list_head waiting_for_map;
	254
	255	struct ceph_mds_session *sessions; / NULL for mds if no session */
	256	int max_sessions; /* len of s_mds_sessions */
	257	int stopping; /* true if shutting down */
	258
	259	/*
	260	* snap_rwsem will cover cap linkage into snaprealms, and
	261	* realm snap contexts. (later, we can do per-realm snap
	262	* contexts locks..) the empty list contains realms with no
	263	* references (implying they contain no inodes with caps) that
	264	* should be destroyed.
	265	*/
	266	struct rw_semaphore snap_rwsem;
a105f00c	267	struct rb_root snap_realms;
2f2dc053 SW	268	struct list_head snap_empty;
	269	spinlock_t snap_empty_lock; /* protect snap_empty */
	270
	271	u64 last_tid; /* most recent mds request */
44ca18f2	272	struct rb_root request_tree; /* pending mds requests */
2f2dc053 SW	273	struct delayed_work delayed_work; /* delayed work */
	274	unsigned long last_renew_caps; /* last time we renewed our caps */
	275	struct list_head cap_delay_list; /* caps with delayed release */
	276	spinlock_t cap_delay_lock; /* protects cap_delay_list */
	277	struct list_head snap_flush_list; /* cap_snaps ready to flush */
	278	spinlock_t snap_flush_lock;
	279
	280	u64 cap_flush_seq;
	281	struct list_head cap_dirty; /* inodes with dirty caps */
db354052	282	struct list_head cap_dirty_migrating; /* ...that are migration... */
2f2dc053 SW	283	int num_cap_flushing; /* # caps we are flushing */
	284	spinlock_t cap_dirty_lock; /* protects above items */
	285	wait_queue_head_t cap_flushing_wq;
	286
37151668 YS	287	/*
	288	* Cap reservations
	289	*
	290	* Maintain a global pool of preallocated struct ceph_caps, referenced
	291	* by struct ceph_caps_reservations. This ensures that we preallocate
	292	* memory needed to successfully process an MDS response. (If an MDS
	293	* sends us cap information and we fail to process it, we will have
	294	* problems due to the client and MDS being out of sync.)
	295	*
	296	* Reservations are 'owned' by a ceph_cap_reservation context.
	297	*/
	298	spinlock_t caps_list_lock;
	299	struct list_head caps_list; /* unused (reserved or
	300	unreserved) */
	301	int caps_total_count; /* total caps allocated */
	302	int caps_use_count; /* in use */
	303	int caps_reserve_count; /* unused, reserved */
	304	int caps_avail_count; /* unused, unreserved */
	305	int caps_min_count; /* keep at least this many
	306	(unreserved) */
2f2dc053 SW	307	spinlock_t dentry_lru_lock;
	308	struct list_head dentry_lru;
	309	int num_dentry;
	310	};
	311
	312	extern const char *ceph_mds_op_name(int op);
	313
	314	extern struct ceph_mds_session *
	315	__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
	316
	317	static inline struct ceph_mds_session *
	318	ceph_get_mds_session(struct ceph_mds_session *s)
	319	{
	320	atomic_inc(&s->s_ref);
	321	return s;
	322	}
	323
	324	extern void ceph_put_mds_session(struct ceph_mds_session *s);
	325
	326	extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
	327	struct ceph_msg *msg, int mds);
	328
3d14c5d2	329	extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
2f2dc053	330	extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
3d14c5d2	331	extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
2f2dc053 SW	332
	333	extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
	334
	335	extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
	336	struct inode *inode,
2f90b852	337	struct dentry *dn);
2f2dc053	338
167c9e35 SW	339	extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
167c9e35 SW	340
2f2dc053 SW	341	extern struct ceph_mds_request *
	342	ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
	343	extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
	344	struct ceph_mds_request *req);
	345	extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
	346	struct inode *dir,
	347	struct ceph_mds_request *req);
	348	static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
	349	{
153c8e6b SW	350	kref_get(&req->r_kref);
	351	}
	352	extern void ceph_mdsc_release_request(struct kref *kref);
	353	static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
	354	{
	355	kref_put(&req->r_kref, ceph_mdsc_release_request);
2f2dc053	356	}
2f2dc053	357
2b2300d6	358	extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
ee6b272b	359	struct ceph_mds_session *session);
3d7ded4d SW	360	extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
	361	struct ceph_mds_session *session);
	362
2f2dc053 SW	363	extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
	364
	365	extern char ceph_mdsc_build_path(struct dentry dentry, int plen, u64 base,
	366	int stop_on_nosnap);
	367
	368	extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
	369	extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
	370	struct inode *inode,
	371	struct dentry *dentry, char action,
	372	u32 seq);
	373
	374	extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
	375	struct ceph_msg *msg);
	376
154f42c2 SW	377	extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
	378	struct ceph_mds_session *session);
	379
2f2dc053	380	#endif