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v3.15
  1#ifndef _FS_CEPH_MDS_CLIENT_H
  2#define _FS_CEPH_MDS_CLIENT_H
  3
  4#include <linux/completion.h>
  5#include <linux/kref.h>
  6#include <linux/list.h>
  7#include <linux/mutex.h>
  8#include <linux/rbtree.h>
  9#include <linux/spinlock.h>
 10
 11#include <linux/ceph/types.h>
 12#include <linux/ceph/messenger.h>
 13#include <linux/ceph/mdsmap.h>
 14#include <linux/ceph/auth.h>
 15
 16/*
 17 * Some lock dependencies:
 18 *
 19 * session->s_mutex
 20 *         mdsc->mutex
 21 *
 22 *         mdsc->snap_rwsem
 23 *
 24 *         ci->i_ceph_lock
 25 *                 mdsc->snap_flush_lock
 26 *                 mdsc->cap_delay_lock
 27 *
 28 */
 29
 30struct ceph_fs_client;
 31struct 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 */
 37struct ceph_mds_reply_info_in {
 38	struct ceph_mds_reply_inode *in;
 39	struct ceph_dir_layout dir_layout;
 40	u32 symlink_len;
 41	char *symlink;
 42	u32 xattr_len;
 43	char *xattr_data;
 44};
 45
 46/*
 47 * parsed info about an mds reply, including information about
 48 * either: 1) the target inode and/or its parent directory and dentry,
 49 * and directory contents (for readdir results), or
 50 * 2) the file range lock info (for fcntl F_GETLK results).
 51 */
 52struct ceph_mds_reply_info_parsed {
 53	struct ceph_mds_reply_head    *head;
 54
 55	/* trace */
 56	struct ceph_mds_reply_info_in diri, targeti;
 57	struct ceph_mds_reply_dirfrag *dirfrag;
 58	char                          *dname;
 59	u32                           dname_len;
 60	struct ceph_mds_reply_lease   *dlease;
 61
 62	/* extra */
 63	union {
 64		/* for fcntl F_GETLK results */
 65		struct ceph_filelock *filelock_reply;
 66
 67		/* for readdir results */
 68		struct {
 69			struct ceph_mds_reply_dirfrag *dir_dir;
 70			size_t			      dir_buf_size;
 71			int                           dir_nr;
 72			char                          **dir_dname;
 73			u32                           *dir_dname_len;
 74			struct ceph_mds_reply_lease   **dir_dlease;
 75			struct ceph_mds_reply_info_in *dir_in;
 76			u8                            dir_complete, dir_end;
 77		};
 78
 79		/* for create results */
 80		struct {
 81			bool has_create_ino;
 82			u64 ino;
 83		};
 84	};
 85
 86	/* encoded blob describing snapshot contexts for certain
 87	   operations (e.g., open) */
 88	void *snapblob;
 89	int snapblob_len;
 90};
 91
 92
 93/*
 94 * cap releases are batched and sent to the MDS en masse.
 95 */
 96#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE -			\
 97				sizeof(struct ceph_mds_cap_release)) /	\
 98			       sizeof(struct ceph_mds_cap_item))
 99
100
101/*
102 * state associated with each MDS<->client session
103 */
104enum {
105	CEPH_MDS_SESSION_NEW = 1,
106	CEPH_MDS_SESSION_OPENING = 2,
107	CEPH_MDS_SESSION_OPEN = 3,
108	CEPH_MDS_SESSION_HUNG = 4,
109	CEPH_MDS_SESSION_CLOSING = 5,
110	CEPH_MDS_SESSION_RESTARTING = 6,
111	CEPH_MDS_SESSION_RECONNECTING = 7,
112};
113
114struct ceph_mds_session {
115	struct ceph_mds_client *s_mdsc;
116	int               s_mds;
117	int               s_state;
118	unsigned long     s_ttl;      /* time until mds kills us */
119	u64               s_seq;      /* incoming msg seq # */
120	struct mutex      s_mutex;    /* serialize session messages */
121
122	struct ceph_connection s_con;
123
124	struct ceph_auth_handshake s_auth;
125
126	/* protected by s_gen_ttl_lock */
127	spinlock_t        s_gen_ttl_lock;
128	u32               s_cap_gen;  /* inc each time we get mds stale msg */
129	unsigned long     s_cap_ttl;  /* when session caps expire */
130
131	/* protected by s_cap_lock */
132	spinlock_t        s_cap_lock;
 
 
133	struct list_head  s_caps;     /* all caps issued by this session */
134	int               s_nr_caps, s_trim_caps;
135	int               s_num_cap_releases;
136	int		  s_cap_reconnect;
137	struct list_head  s_cap_releases; /* waiting cap_release messages */
138	struct list_head  s_cap_releases_done; /* ready to send */
139	struct ceph_cap  *s_cap_iterator;
140
141	/* protected by mutex */
142	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
143	struct list_head  s_cap_snaps_flushing;
144	unsigned long     s_renew_requested; /* last time we sent a renew req */
145	u64               s_renew_seq;
146
147	atomic_t          s_ref;
148	struct list_head  s_waiting;  /* waiting requests */
149	struct list_head  s_unsafe;   /* unsafe requests */
150};
151
152/*
153 * modes of choosing which MDS to send a request to
154 */
155enum {
156	USE_ANY_MDS,
157	USE_RANDOM_MDS,
158	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
159};
160
161struct ceph_mds_request;
162struct ceph_mds_client;
163
164/*
165 * request completion callback
166 */
167typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
168					     struct ceph_mds_request *req);
169
170/*
171 * an in-flight mds request
172 */
173struct ceph_mds_request {
174	u64 r_tid;                   /* transaction id */
175	struct rb_node r_node;
176	struct ceph_mds_client *r_mdsc;
177
178	int r_op;                    /* mds op code */
179
180	/* operation on what? */
181	struct inode *r_inode;              /* arg1 */
182	struct dentry *r_dentry;            /* arg1 */
183	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
184	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
185	char *r_path1, *r_path2;
186	struct ceph_vino r_ino1, r_ino2;
187
188	struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
189	struct inode *r_target_inode;       /* resulting inode */
190
191	struct mutex r_fill_mutex;
192
193	union ceph_mds_request_args r_args;
194	int r_fmode;        /* file mode, if expecting cap */
195	kuid_t r_uid;
196	kgid_t r_gid;
197
198	/* for choosing which mds to send this request to */
199	int r_direct_mode;
200	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
201	bool r_direct_is_hash;  /* true if r_direct_hash is valid */
202
203	/* data payload is used for xattr ops */
204	struct page **r_pages;
205	int r_num_pages;
206	int r_data_len;
207
208	/* what caps shall we drop? */
209	int r_inode_drop, r_inode_unless;
210	int r_dentry_drop, r_dentry_unless;
211	int r_old_dentry_drop, r_old_dentry_unless;
212	struct inode *r_old_inode;
213	int r_old_inode_drop, r_old_inode_unless;
214
215	struct ceph_msg  *r_request;  /* original request */
216	int r_request_release_offset;
217	struct ceph_msg  *r_reply;
218	struct ceph_mds_reply_info_parsed r_reply_info;
219	int r_err;
220	bool r_aborted;
221
222	unsigned long r_timeout;  /* optional.  jiffies */
223	unsigned long r_started;  /* start time to measure timeout against */
224	unsigned long r_request_started; /* start time for mds request only,
225					    used to measure lease durations */
226
227	/* link unsafe requests to parent directory, for fsync */
228	struct inode	*r_unsafe_dir;
229	struct list_head r_unsafe_dir_item;
230
231	struct ceph_mds_session *r_session;
232
233	int               r_attempts;   /* resend attempts */
234	int               r_num_fwd;    /* number of forward attempts */
235	int               r_resend_mds; /* mds to resend to next, if any*/
236	u32               r_sent_on_mseq; /* cap mseq request was sent at*/
237
238	struct kref       r_kref;
239	struct list_head  r_wait;
240	struct completion r_completion;
241	struct completion r_safe_completion;
242	ceph_mds_request_callback_t r_callback;
243	struct list_head  r_unsafe_item;  /* per-session unsafe list item */
244	bool		  r_got_unsafe, r_got_safe, r_got_result;
245
246	bool              r_did_prepopulate;
247	u32               r_readdir_offset;
248
249	struct ceph_cap_reservation r_caps_reservation;
250	int r_num_caps;
251};
252
253/*
254 * mds client state
255 */
256struct ceph_mds_client {
257	struct ceph_fs_client  *fsc;
258	struct mutex            mutex;         /* all nested structures */
259
260	struct ceph_mdsmap      *mdsmap;
261	struct completion       safe_umount_waiters;
262	wait_queue_head_t       session_close_wq;
263	struct list_head        waiting_for_map;
264
265	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
266	int                     max_sessions;  /* len of s_mds_sessions */
267	int                     stopping;      /* true if shutting down */
268
269	/*
270	 * snap_rwsem will cover cap linkage into snaprealms, and
271	 * realm snap contexts.  (later, we can do per-realm snap
272	 * contexts locks..)  the empty list contains realms with no
273	 * references (implying they contain no inodes with caps) that
274	 * should be destroyed.
275	 */
276	struct rw_semaphore     snap_rwsem;
277	struct rb_root          snap_realms;
278	struct list_head        snap_empty;
279	spinlock_t              snap_empty_lock;  /* protect snap_empty */
280
281	u64                    last_tid;      /* most recent mds request */
282	struct rb_root         request_tree;  /* pending mds requests */
283	struct delayed_work    delayed_work;  /* delayed work */
284	unsigned long    last_renew_caps;  /* last time we renewed our caps */
285	struct list_head cap_delay_list;   /* caps with delayed release */
286	spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
287	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
288	spinlock_t       snap_flush_lock;
289
290	u64               cap_flush_seq;
291	struct list_head  cap_dirty;        /* inodes with dirty caps */
292	struct list_head  cap_dirty_migrating; /* ...that are migration... */
293	int               num_cap_flushing; /* # caps we are flushing */
294	spinlock_t        cap_dirty_lock;   /* protects above items */
295	wait_queue_head_t cap_flushing_wq;
296
297	/*
298	 * Cap reservations
299	 *
300	 * Maintain a global pool of preallocated struct ceph_caps, referenced
301	 * by struct ceph_caps_reservations.  This ensures that we preallocate
302	 * memory needed to successfully process an MDS response.  (If an MDS
303	 * sends us cap information and we fail to process it, we will have
304	 * problems due to the client and MDS being out of sync.)
305	 *
306	 * Reservations are 'owned' by a ceph_cap_reservation context.
307	 */
308	spinlock_t	caps_list_lock;
309	struct		list_head caps_list; /* unused (reserved or
310						unreserved) */
311	int		caps_total_count;    /* total caps allocated */
312	int		caps_use_count;      /* in use */
313	int		caps_reserve_count;  /* unused, reserved */
314	int		caps_avail_count;    /* unused, unreserved */
315	int		caps_min_count;      /* keep at least this many
316						(unreserved) */
317	spinlock_t	  dentry_lru_lock;
318	struct list_head  dentry_lru;
319	int		  num_dentry;
320};
321
322extern const char *ceph_mds_op_name(int op);
323
324extern struct ceph_mds_session *
325__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
326
327static inline struct ceph_mds_session *
328ceph_get_mds_session(struct ceph_mds_session *s)
329{
330	atomic_inc(&s->s_ref);
331	return s;
332}
333
334extern void ceph_put_mds_session(struct ceph_mds_session *s);
335
336extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
337			     struct ceph_msg *msg, int mds);
338
339extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
340extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
341extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
342
343extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
344
345extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
346				    struct inode *inode,
347				    struct dentry *dn);
348
349extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
350extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
351					   struct inode *dir);
352extern struct ceph_mds_request *
353ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
354extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
355				     struct ceph_mds_request *req);
356extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
357				struct inode *dir,
358				struct ceph_mds_request *req);
359static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
360{
361	kref_get(&req->r_kref);
362}
363extern void ceph_mdsc_release_request(struct kref *kref);
364static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
365{
366	kref_put(&req->r_kref, ceph_mdsc_release_request);
367}
368
369extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
370				 struct ceph_mds_session *session);
371extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
372				   struct ceph_mds_session *session);
373
374extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
375
376extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
377				  int stop_on_nosnap);
378
379extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
380extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
381				     struct inode *inode,
382				     struct dentry *dentry, char action,
383				     u32 seq);
384
385extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
386				 struct ceph_msg *msg);
387
388extern struct ceph_mds_session *
389ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
390extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
391					  struct ceph_mds_session *session);
392
393#endif
v3.1
  1#ifndef _FS_CEPH_MDS_CLIENT_H
  2#define _FS_CEPH_MDS_CLIENT_H
  3
  4#include <linux/completion.h>
  5#include <linux/kref.h>
  6#include <linux/list.h>
  7#include <linux/mutex.h>
  8#include <linux/rbtree.h>
  9#include <linux/spinlock.h>
 10
 11#include <linux/ceph/types.h>
 12#include <linux/ceph/messenger.h>
 13#include <linux/ceph/mdsmap.h>
 
 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
 29struct ceph_fs_client;
 30struct 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 */
 36struct ceph_mds_reply_info_in {
 37	struct ceph_mds_reply_inode *in;
 38	struct ceph_dir_layout dir_layout;
 39	u32 symlink_len;
 40	char *symlink;
 41	u32 xattr_len;
 42	char *xattr_data;
 43};
 44
 45/*
 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).
 50 */
 51struct ceph_mds_reply_info_parsed {
 52	struct ceph_mds_reply_head    *head;
 53
 54	/* trace */
 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
 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	};
 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 */
 96enum {
 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
106struct 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
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
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 */
129	struct ceph_cap  *s_cap_iterator;
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 */
145enum {
146	USE_ANY_MDS,
147	USE_RANDOM_MDS,
148	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
149};
150
151struct ceph_mds_request;
152struct ceph_mds_client;
153
154/*
155 * request completion callback
156 */
157typedef 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 */
163struct ceph_mds_request {
164	u64 r_tid;                   /* transaction id */
165	struct rb_node r_node;
166	struct ceph_mds_client *r_mdsc;
167
168	int r_op;                    /* mds op code */
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	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
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
181	struct mutex r_fill_mutex;
182
183	union ceph_mds_request_args r_args;
184	int r_fmode;        /* file mode, if expecting cap */
185	uid_t r_uid;
186	gid_t r_gid;
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 */
206	int r_request_release_offset;
207	struct ceph_msg  *r_reply;
208	struct ceph_mds_reply_info_parsed r_reply_info;
209	int r_err;
210	bool r_aborted;
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 */
225	int               r_resend_mds; /* mds to resend to next, if any*/
226	u32               r_sent_on_mseq; /* cap mseq request was sent at*/
227
228	struct kref       r_kref;
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 */
234	bool		  r_got_unsafe, r_got_safe, r_got_result;
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 */
246struct ceph_mds_client {
247	struct ceph_fs_client  *fsc;
248	struct mutex            mutex;         /* all nested structures */
249
250	struct ceph_mdsmap      *mdsmap;
251	struct completion       safe_umount_waiters;
252	wait_queue_head_t       session_close_wq;
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;
267	struct rb_root          snap_realms;
268	struct list_head        snap_empty;
269	spinlock_t              snap_empty_lock;  /* protect snap_empty */
270
271	u64                    last_tid;      /* most recent mds request */
272	struct rb_root         request_tree;  /* pending mds requests */
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 */
282	struct list_head  cap_dirty_migrating; /* ...that are migration... */
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
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) */
307	spinlock_t	  dentry_lru_lock;
308	struct list_head  dentry_lru;
309	int		  num_dentry;
310};
311
312extern const char *ceph_mds_op_name(int op);
313
314extern struct ceph_mds_session *
315__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
316
317static inline struct ceph_mds_session *
318ceph_get_mds_session(struct ceph_mds_session *s)
319{
320	atomic_inc(&s->s_ref);
321	return s;
322}
323
324extern void ceph_put_mds_session(struct ceph_mds_session *s);
325
326extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
327			     struct ceph_msg *msg, int mds);
328
329extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
330extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
331extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
332
333extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
334
335extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
336				    struct inode *inode,
337				    struct dentry *dn);
338
339extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
340
 
341extern struct ceph_mds_request *
342ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
343extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
344				     struct ceph_mds_request *req);
345extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
346				struct inode *dir,
347				struct ceph_mds_request *req);
348static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
349{
350	kref_get(&req->r_kref);
351}
352extern void ceph_mdsc_release_request(struct kref *kref);
353static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
354{
355	kref_put(&req->r_kref, ceph_mdsc_release_request);
356}
357
358extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
359				 struct ceph_mds_session *session);
360extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
361				   struct ceph_mds_session *session);
362
363extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
364
365extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
366				  int stop_on_nosnap);
367
368extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
369extern 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
374extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
375				 struct ceph_msg *msg);
376
 
 
377extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
378					  struct ceph_mds_session *session);
379
380#endif