[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>
#include <linux/ceph/auth.h>

/*
 * Some lock dependencies:
 *
 * session->s_mutex
 *         mdsc->mutex
 *
 *         mdsc->snap_rwsem
 *
 *         ci->i_ceph_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;
	u64 inline_version;
	u32 inline_len;
	char *inline_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;
			size_t			      dir_buf_size;
			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;
		};

		/* for create results */
		struct {
			bool has_create_ino;
			u64 ino;
		};
	};

	/* 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_auth_handshake s_auth;

	/* protected by s_gen_ttl_lock */
	spinlock_t        s_gen_ttl_lock;
	u32               s_cap_gen;  /* inc each time we get mds stale msg */
	unsigned long     s_cap_ttl;  /* when session caps expire */

	/* protected by s_cap_lock */
	spinlock_t        s_cap_lock;
	struct list_head  s_caps;     /* all caps issued by this session */
	int               s_nr_caps, s_trim_caps;
	int               s_num_cap_releases;
	int		  s_cap_reconnect;
	int		  s_readonly;
	struct list_head  s_cap_releases; /* waiting cap_release messages */
	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);
/*
 * wait for request completion callback
 */
typedef int (*ceph_mds_request_wait_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 */
	kuid_t r_uid;
	kgid_t r_gid;
	struct timespec r_stamp;

	/* 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 ceph_pagelist *r_pagelist;

	/* 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;
	struct page *r_locked_page;
	int r_err;
	bool r_aborted;

	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
	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;

	/* unsafe requests that modify the target inode */
	struct list_head r_unsafe_target_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;
	ceph_mds_request_wait_callback_t r_wait_for_completion;
	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;
	long long	  r_dir_release_cnt;
	long long	  r_dir_ordered_cnt;
	int		  r_readdir_cache_idx;
	u32               r_readdir_offset;

	struct ceph_cap_reservation r_caps_reservation;
	int r_num_caps;
};

struct ceph_pool_perm {
	struct rb_node node;
	u32 pool;
	int perm;
};

/*
 * 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 */
	atomic_t		num_sessions;
	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.
	 */
	u64			last_snap_seq;
	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 */
	u64                    oldest_tid;    /* oldest incomplete mds request,
						 excluding setfilelock requests */
	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               last_cap_flush_tid;
	struct rb_root    cap_flush_tree;
	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;

	struct rw_semaphore     pool_perm_rwsem;
	struct rb_root		pool_perm_tree;
};

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 const char *ceph_session_state_name(int 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_force_umount(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 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
					   struct inode *dir);
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 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 struct ceph_mds_session *
ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
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>
6c4a1915	14	#include <linux/ceph/auth.h>
2f2dc053 SW	15
	16	/*
	17	* Some lock dependencies:
	18	*
	19	* session->s_mutex
	20	* mdsc->mutex
	21	*
	22	* mdsc->snap_rwsem
	23	*
be655596	24	* ci->i_ceph_lock
2f2dc053 SW	25	* mdsc->snap_flush_lock
	26	* mdsc->cap_delay_lock
	27	*
	28	*/
	29
3d14c5d2	30	struct ceph_fs_client;
2f2dc053 SW	31	struct ceph_cap;
	32
	33	/*
	34	* parsed info about a single inode. pointers are into the encoded
	35	* on-wire structures within the mds reply message payload.
	36	*/
	37	struct ceph_mds_reply_info_in {
	38	struct ceph_mds_reply_inode *in;
14303d20	39	struct ceph_dir_layout dir_layout;
2f2dc053 SW	40	u32 symlink_len;
	41	char *symlink;
	42	u32 xattr_len;
	43	char *xattr_data;
fb01d1f8 YZ	44	u64 inline_version;
	45	u32 inline_len;
	46	char *inline_data;
2f2dc053 SW	47	};
	48
	49	/*
25933abd HS	50	* parsed info about an mds reply, including information about
	51	* either: 1) the target inode and/or its parent directory and dentry,
	52	* and directory contents (for readdir results), or
	53	* 2) the file range lock info (for fcntl F_GETLK results).
2f2dc053 SW	54	*/
	55	struct ceph_mds_reply_info_parsed {
	56	struct ceph_mds_reply_head *head;
	57
25933abd	58	/* trace */
2f2dc053 SW	59	struct ceph_mds_reply_info_in diri, targeti;
	60	struct ceph_mds_reply_dirfrag *dirfrag;
	61	char *dname;
	62	u32 dname_len;
	63	struct ceph_mds_reply_lease *dlease;
	64
25933abd HS	65	/* extra */
	66	union {
	67	/* for fcntl F_GETLK results */
	68	struct ceph_filelock *filelock_reply;
	69
	70	/* for readdir results */
	71	struct {
	72	struct ceph_mds_reply_dirfrag *dir_dir;
54008399	73	size_t dir_buf_size;
25933abd HS	74	int dir_nr;
	75	char **dir_dname;
	76	u32 *dir_dname_len;
	77	struct ceph_mds_reply_lease **dir_dlease;
	78	struct ceph_mds_reply_info_in *dir_in;
	79	u8 dir_complete, dir_end;
	80	};
6e8575fa SL	81
	82	/* for create results */
	83	struct {
	84	bool has_create_ino;
	85	u64 ino;
	86	};
25933abd	87	};
2f2dc053 SW	88
	89	/* encoded blob describing snapshot contexts for certain
	90	operations (e.g., open) */
	91	void *snapblob;
	92	int snapblob_len;
	93	};
	94
	95
	96	/*
	97	* cap releases are batched and sent to the MDS en masse.
	98	*/
	99	#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \
	100	sizeof(struct ceph_mds_cap_release)) / \
	101	sizeof(struct ceph_mds_cap_item))
	102
	103
	104	/*
	105	* state associated with each MDS<->client session
	106	*/
	107	enum {
	108	CEPH_MDS_SESSION_NEW = 1,
	109	CEPH_MDS_SESSION_OPENING = 2,
	110	CEPH_MDS_SESSION_OPEN = 3,
	111	CEPH_MDS_SESSION_HUNG = 4,
	112	CEPH_MDS_SESSION_CLOSING = 5,
	113	CEPH_MDS_SESSION_RESTARTING = 6,
	114	CEPH_MDS_SESSION_RECONNECTING = 7,
	115	};
	116
	117	struct ceph_mds_session {
	118	struct ceph_mds_client *s_mdsc;
	119	int s_mds;
	120	int s_state;
	121	unsigned long s_ttl; /* time until mds kills us */
	122	u64 s_seq; /* incoming msg seq # */
	123	struct mutex s_mutex; /* serialize session messages */
	124
	125	struct ceph_connection s_con;
	126
6c4a1915	127	struct ceph_auth_handshake s_auth;
4e7a5dcd	128
d8fb02ab AE	129	/* protected by s_gen_ttl_lock */
d8fb02ab AE	130	spinlock_t s_gen_ttl_lock;
2f2dc053 SW	131	u32 s_cap_gen; /* inc each time we get mds stale msg */
2f2dc053 SW	132	unsigned long s_cap_ttl; /* when session caps expire */
d8fb02ab AE	133
	134	/* protected by s_cap_lock */
	135	spinlock_t s_cap_lock;
2f2dc053 SW	136	struct list_head s_caps; /* all caps issued by this session */
	137	int s_nr_caps, s_trim_caps;
	138	int s_num_cap_releases;
99a9c273	139	int s_cap_reconnect;
03f4fcb0	140	int s_readonly;
2f2dc053	141	struct list_head s_cap_releases; /* waiting cap_release messages */
7c1332b8	142	struct ceph_cap *s_cap_iterator;
2f2dc053 SW	143
	144	/* protected by mutex */
	145	struct list_head s_cap_flushing; /* inodes w/ flushing caps */
	146	struct list_head s_cap_snaps_flushing;
	147	unsigned long s_renew_requested; /* last time we sent a renew req */
	148	u64 s_renew_seq;
	149
	150	atomic_t s_ref;
	151	struct list_head s_waiting; /* waiting requests */
	152	struct list_head s_unsafe; /* unsafe requests */
	153	};
	154
	155	/*
	156	* modes of choosing which MDS to send a request to
	157	*/
	158	enum {
	159	USE_ANY_MDS,
	160	USE_RANDOM_MDS,
	161	USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
	162	};
	163
	164	struct ceph_mds_request;
	165	struct ceph_mds_client;
	166
	167	/*
	168	* request completion callback
	169	*/
	170	typedef void (ceph_mds_request_callback_t) (struct ceph_mds_client mdsc,
	171	struct ceph_mds_request *req);
9280be24 YZ	172	/*
	173	* wait for request completion callback
	174	*/
	175	typedef int (ceph_mds_request_wait_callback_t) (struct ceph_mds_client mdsc,
	176	struct ceph_mds_request *req);
2f2dc053 SW	177
	178	/*
	179	* an in-flight mds request
	180	*/
	181	struct ceph_mds_request {
	182	u64 r_tid; /* transaction id */
44ca18f2	183	struct rb_node r_node;
37151668	184	struct ceph_mds_client *r_mdsc;
2f2dc053 SW	185
2f2dc053 SW	186	int r_op; /* mds op code */
2f2dc053 SW	187
	188	/* operation on what? */
	189	struct inode r_inode; / arg1 */
	190	struct dentry r_dentry; / arg1 */
	191	struct dentry r_old_dentry; / arg2: rename from or link from */
41b02e1f	192	struct inode r_old_dentry_dir; / arg2: old dentry's parent dir */
2f2dc053 SW	193	char r_path1, r_path2;
	194	struct ceph_vino r_ino1, r_ino2;
	195
	196	struct inode r_locked_dir; / dir (if any) i_mutex locked by vfs */
	197	struct inode r_target_inode; / resulting inode */
	198
b4556396 SW	199	struct mutex r_fill_mutex;
b4556396 SW	200
2f2dc053 SW	201	union ceph_mds_request_args r_args;
2f2dc053 SW	202	int r_fmode; /* file mode, if expecting cap */
ff3d0046 EB	203	kuid_t r_uid;
ff3d0046 EB	204	kgid_t r_gid;
b8e69066	205	struct timespec r_stamp;
2f2dc053 SW	206
	207	/* for choosing which mds to send this request to */
	208	int r_direct_mode;
	209	u32 r_direct_hash; /* choose dir frag based on this dentry hash */
	210	bool r_direct_is_hash; /* true if r_direct_hash is valid */
	211
	212	/* data payload is used for xattr ops */
25e6bae3	213	struct ceph_pagelist *r_pagelist;
2f2dc053 SW	214
	215	/* what caps shall we drop? */
	216	int r_inode_drop, r_inode_unless;
	217	int r_dentry_drop, r_dentry_unless;
	218	int r_old_dentry_drop, r_old_dentry_unless;
	219	struct inode *r_old_inode;
	220	int r_old_inode_drop, r_old_inode_unless;
	221
	222	struct ceph_msg r_request; / original request */
e979cf50	223	int r_request_release_offset;
2f2dc053 SW	224	struct ceph_msg *r_reply;
2f2dc053 SW	225	struct ceph_mds_reply_info_parsed r_reply_info;
01deead0	226	struct page *r_locked_page;
2f2dc053	227	int r_err;
5b1daecd	228	bool r_aborted;
2f2dc053	229
a319bf56	230	unsigned long r_timeout; /* optional. jiffies, 0 is "wait forever" */
2f2dc053 SW	231	unsigned long r_started; /* start time to measure timeout against */
	232	unsigned long r_request_started; /* start time for mds request only,
	233	used to measure lease durations */
	234
	235	/* link unsafe requests to parent directory, for fsync */
	236	struct inode *r_unsafe_dir;
	237	struct list_head r_unsafe_dir_item;
	238
68cd5b4b YZ	239	/* unsafe requests that modify the target inode */
	240	struct list_head r_unsafe_target_item;
	241
2f2dc053 SW	242	struct ceph_mds_session *r_session;
	243
	244	int r_attempts; /* resend attempts */
	245	int r_num_fwd; /* number of forward attempts */
2f2dc053	246	int r_resend_mds; /* mds to resend to next, if any*/
e55b71f8	247	u32 r_sent_on_mseq; /* cap mseq request was sent at*/
2f2dc053	248
153c8e6b	249	struct kref r_kref;
2f2dc053 SW	250	struct list_head r_wait;
	251	struct completion r_completion;
	252	struct completion r_safe_completion;
	253	ceph_mds_request_callback_t r_callback;
9280be24	254	ceph_mds_request_wait_callback_t r_wait_for_completion;
2f2dc053	255	struct list_head r_unsafe_item; /* per-session unsafe list item */
e1518c7c	256	bool r_got_unsafe, r_got_safe, r_got_result;
2f2dc053 SW	257
2f2dc053 SW	258	bool r_did_prepopulate;
fdd4e158 YZ	259	long long r_dir_release_cnt;
	260	long long r_dir_ordered_cnt;
	261	int r_readdir_cache_idx;
2f2dc053 SW	262	u32 r_readdir_offset;
	263
	264	struct ceph_cap_reservation r_caps_reservation;
	265	int r_num_caps;
	266	};
	267
10183a69 YZ	268	struct ceph_pool_perm {
	269	struct rb_node node;
	270	u32 pool;
	271	int perm;
	272	};
	273
2f2dc053 SW	274	/*
	275	* mds client state
	276	*/
	277	struct ceph_mds_client {
3d14c5d2	278	struct ceph_fs_client *fsc;
2f2dc053 SW	279	struct mutex mutex; /* all nested structures */
	280
	281	struct ceph_mdsmap *mdsmap;
f3c60c59 SW	282	struct completion safe_umount_waiters;
f3c60c59 SW	283	wait_queue_head_t session_close_wq;
2f2dc053 SW	284	struct list_head waiting_for_map;
	285
	286	struct ceph_mds_session *sessions; / NULL for mds if no session */
86d8f67b	287	atomic_t num_sessions;
2f2dc053 SW	288	int max_sessions; /* len of s_mds_sessions */
	289	int stopping; /* true if shutting down */
	290
	291	/*
	292	* snap_rwsem will cover cap linkage into snaprealms, and
	293	* realm snap contexts. (later, we can do per-realm snap
	294	* contexts locks..) the empty list contains realms with no
	295	* references (implying they contain no inodes with caps) that
	296	* should be destroyed.
	297	*/
affbc19a	298	u64 last_snap_seq;
2f2dc053	299	struct rw_semaphore snap_rwsem;
a105f00c	300	struct rb_root snap_realms;
2f2dc053 SW	301	struct list_head snap_empty;
	302	spinlock_t snap_empty_lock; /* protect snap_empty */
	303
	304	u64 last_tid; /* most recent mds request */
e8a7b8b1 YZ	305	u64 oldest_tid; /* oldest incomplete mds request,
e8a7b8b1 YZ	306	excluding setfilelock requests */
44ca18f2	307	struct rb_root request_tree; /* pending mds requests */
2f2dc053 SW	308	struct delayed_work delayed_work; /* delayed work */
	309	unsigned long last_renew_caps; /* last time we renewed our caps */
	310	struct list_head cap_delay_list; /* caps with delayed release */
	311	spinlock_t cap_delay_lock; /* protects cap_delay_list */
	312	struct list_head snap_flush_list; /* cap_snaps ready to flush */
	313	spinlock_t snap_flush_lock;
	314
553adfd9	315	u64 last_cap_flush_tid;
8310b089	316	struct rb_root cap_flush_tree;
2f2dc053	317	struct list_head cap_dirty; /* inodes with dirty caps */
db354052	318	struct list_head cap_dirty_migrating; /* ...that are migration... */
2f2dc053 SW	319	int num_cap_flushing; /* # caps we are flushing */
	320	spinlock_t cap_dirty_lock; /* protects above items */
	321	wait_queue_head_t cap_flushing_wq;
	322
37151668 YS	323	/*
	324	* Cap reservations
	325	*
	326	* Maintain a global pool of preallocated struct ceph_caps, referenced
	327	* by struct ceph_caps_reservations. This ensures that we preallocate
	328	* memory needed to successfully process an MDS response. (If an MDS
	329	* sends us cap information and we fail to process it, we will have
	330	* problems due to the client and MDS being out of sync.)
	331	*
	332	* Reservations are 'owned' by a ceph_cap_reservation context.
	333	*/
	334	spinlock_t caps_list_lock;
	335	struct list_head caps_list; /* unused (reserved or
	336	unreserved) */
	337	int caps_total_count; /* total caps allocated */
	338	int caps_use_count; /* in use */
	339	int caps_reserve_count; /* unused, reserved */
	340	int caps_avail_count; /* unused, unreserved */
	341	int caps_min_count; /* keep at least this many
	342	(unreserved) */
2f2dc053 SW	343	spinlock_t dentry_lru_lock;
	344	struct list_head dentry_lru;
	345	int num_dentry;
10183a69 YZ	346
	347	struct rw_semaphore pool_perm_rwsem;
	348	struct rb_root pool_perm_tree;
2f2dc053 SW	349	};
	350
	351	extern const char *ceph_mds_op_name(int op);
	352
	353	extern struct ceph_mds_session *
	354	__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
	355
	356	static inline struct ceph_mds_session *
	357	ceph_get_mds_session(struct ceph_mds_session *s)
	358	{
	359	atomic_inc(&s->s_ref);
	360	return s;
	361	}
	362
a687ecaf JS	363	extern const char *ceph_session_state_name(int s);
a687ecaf JS	364
2f2dc053 SW	365	extern void ceph_put_mds_session(struct ceph_mds_session *s);
	366
	367	extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
	368	struct ceph_msg *msg, int mds);
	369
3d14c5d2	370	extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
2f2dc053	371	extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
48fec5d0	372	extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
3d14c5d2	373	extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
2f2dc053 SW	374
	375	extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
	376
	377	extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
	378	struct inode *inode,
2f90b852	379	struct dentry *dn);
2f2dc053	380
167c9e35	381	extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
54008399 YZ	382	extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
54008399 YZ	383	struct inode *dir);
2f2dc053 SW	384	extern struct ceph_mds_request *
	385	ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
	386	extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
	387	struct ceph_mds_request *req);
	388	extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
	389	struct inode *dir,
	390	struct ceph_mds_request *req);
	391	static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
	392	{
153c8e6b SW	393	kref_get(&req->r_kref);
	394	}
	395	extern void ceph_mdsc_release_request(struct kref *kref);
	396	static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
	397	{
	398	kref_put(&req->r_kref, ceph_mdsc_release_request);
2f2dc053	399	}
2f2dc053	400
3d7ded4d SW	401	extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
	402	struct ceph_mds_session *session);
	403
2f2dc053 SW	404	extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
	405
	406	extern char ceph_mdsc_build_path(struct dentry dentry, int plen, u64 base,
	407	int stop_on_nosnap);
	408
	409	extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
	410	extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
	411	struct inode *inode,
	412	struct dentry *dentry, char action,
	413	u32 seq);
	414
	415	extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
	416	struct ceph_msg *msg);
	417
5d72d13c YZ	418	extern struct ceph_mds_session *
5d72d13c YZ	419	ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
154f42c2 SW	420	extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
	421	struct ceph_mds_session *session);
	422
2f2dc053	423	#endif