[GitHub/mt8127/android_kernel_alcatel_ttab.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;
	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 */
	int r_mds;

	/* operation on what? */
	struct inode *r_inode;              /* arg1 */
	struct dentry *r_dentry;            /* arg1 */
	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
	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 */
	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, int mask);

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