xref: /openbmc/linux/fs/ceph/mds_client.h (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1  /* SPDX-License-Identifier: GPL-2.0 */
2  #ifndef _FS_CEPH_MDS_CLIENT_H
3  #define _FS_CEPH_MDS_CLIENT_H
4  
5  #include <linux/completion.h>
6  #include <linux/kref.h>
7  #include <linux/list.h>
8  #include <linux/mutex.h>
9  #include <linux/rbtree.h>
10  #include <linux/spinlock.h>
11  #include <linux/refcount.h>
12  #include <linux/utsname.h>
13  #include <linux/ktime.h>
14  
15  #include <linux/ceph/types.h>
16  #include <linux/ceph/messenger.h>
17  #include <linux/ceph/mdsmap.h>
18  #include <linux/ceph/auth.h>
19  
20  #include "metric.h"
21  #include "super.h"
22  
23  /* The first 8 bits are reserved for old ceph releases */
24  enum ceph_feature_type {
25  	CEPHFS_FEATURE_MIMIC = 8,
26  	CEPHFS_FEATURE_REPLY_ENCODING,
27  	CEPHFS_FEATURE_RECLAIM_CLIENT,
28  	CEPHFS_FEATURE_LAZY_CAP_WANTED,
29  	CEPHFS_FEATURE_MULTI_RECONNECT,
30  	CEPHFS_FEATURE_DELEG_INO,
31  	CEPHFS_FEATURE_METRIC_COLLECT,
32  	CEPHFS_FEATURE_ALTERNATE_NAME,
33  	CEPHFS_FEATURE_NOTIFY_SESSION_STATE,
34  	CEPHFS_FEATURE_OP_GETVXATTR,
35  	CEPHFS_FEATURE_32BITS_RETRY_FWD,
36  
37  	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_32BITS_RETRY_FWD,
38  };
39  
40  #define CEPHFS_FEATURES_CLIENT_SUPPORTED {	\
41  	0, 1, 2, 3, 4, 5, 6, 7,			\
42  	CEPHFS_FEATURE_MIMIC,			\
43  	CEPHFS_FEATURE_REPLY_ENCODING,		\
44  	CEPHFS_FEATURE_LAZY_CAP_WANTED,		\
45  	CEPHFS_FEATURE_MULTI_RECONNECT,		\
46  	CEPHFS_FEATURE_DELEG_INO,		\
47  	CEPHFS_FEATURE_METRIC_COLLECT,		\
48  	CEPHFS_FEATURE_ALTERNATE_NAME,		\
49  	CEPHFS_FEATURE_NOTIFY_SESSION_STATE,	\
50  	CEPHFS_FEATURE_OP_GETVXATTR,		\
51  	CEPHFS_FEATURE_32BITS_RETRY_FWD,	\
52  }
53  
54  /*
55   * Some lock dependencies:
56   *
57   * session->s_mutex
58   *         mdsc->mutex
59   *
60   *         mdsc->snap_rwsem
61   *
62   *         ci->i_ceph_lock
63   *                 mdsc->snap_flush_lock
64   *                 mdsc->cap_delay_lock
65   *
66   */
67  
68  struct ceph_fs_client;
69  struct ceph_cap;
70  
71  /*
72   * parsed info about a single inode.  pointers are into the encoded
73   * on-wire structures within the mds reply message payload.
74   */
75  struct ceph_mds_reply_info_in {
76  	struct ceph_mds_reply_inode *in;
77  	struct ceph_dir_layout dir_layout;
78  	u32 symlink_len;
79  	char *symlink;
80  	u32 xattr_len;
81  	char *xattr_data;
82  	u64 inline_version;
83  	u32 inline_len;
84  	char *inline_data;
85  	u32 pool_ns_len;
86  	char *pool_ns_data;
87  	u64 max_bytes;
88  	u64 max_files;
89  	s32 dir_pin;
90  	struct ceph_timespec btime;
91  	struct ceph_timespec snap_btime;
92  	u8 *fscrypt_auth;
93  	u8 *fscrypt_file;
94  	u32 fscrypt_auth_len;
95  	u32 fscrypt_file_len;
96  	u64 rsnaps;
97  	u64 change_attr;
98  };
99  
100  struct ceph_mds_reply_dir_entry {
101  	bool			      is_nokey;
102  	char                          *name;
103  	u32                           name_len;
104  	u32			      raw_hash;
105  	struct ceph_mds_reply_lease   *lease;
106  	struct ceph_mds_reply_info_in inode;
107  	loff_t			      offset;
108  };
109  
110  struct ceph_mds_reply_xattr {
111  	char *xattr_value;
112  	size_t xattr_value_len;
113  };
114  
115  /*
116   * parsed info about an mds reply, including information about
117   * either: 1) the target inode and/or its parent directory and dentry,
118   * and directory contents (for readdir results), or
119   * 2) the file range lock info (for fcntl F_GETLK results).
120   */
121  struct ceph_mds_reply_info_parsed {
122  	struct ceph_mds_reply_head    *head;
123  
124  	/* trace */
125  	struct ceph_mds_reply_info_in diri, targeti;
126  	struct ceph_mds_reply_dirfrag *dirfrag;
127  	char                          *dname;
128  	u8			      *altname;
129  	u32                           dname_len;
130  	u32                           altname_len;
131  	struct ceph_mds_reply_lease   *dlease;
132  	struct ceph_mds_reply_xattr   xattr_info;
133  
134  	/* extra */
135  	union {
136  		/* for fcntl F_GETLK results */
137  		struct ceph_filelock *filelock_reply;
138  
139  		/* for readdir results */
140  		struct {
141  			struct ceph_mds_reply_dirfrag *dir_dir;
142  			size_t			      dir_buf_size;
143  			int                           dir_nr;
144  			bool			      dir_end;
145  			bool			      dir_complete;
146  			bool			      hash_order;
147  			bool			      offset_hash;
148  			struct ceph_mds_reply_dir_entry  *dir_entries;
149  		};
150  
151  		/* for create results */
152  		struct {
153  			bool has_create_ino;
154  			u64 ino;
155  		};
156  	};
157  
158  	/* encoded blob describing snapshot contexts for certain
159  	   operations (e.g., open) */
160  	void *snapblob;
161  	int snapblob_len;
162  };
163  
164  
165  /*
166   * cap releases are batched and sent to the MDS en masse.
167   *
168   * Account for per-message overhead of mds_cap_release header
169   * and __le32 for osd epoch barrier trailing field.
170   */
171  #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -		\
172  				sizeof(struct ceph_mds_cap_release)) /	\
173  			        sizeof(struct ceph_mds_cap_item))
174  
175  
176  /*
177   * state associated with each MDS<->client session
178   */
179  enum {
180  	CEPH_MDS_SESSION_NEW = 1,
181  	CEPH_MDS_SESSION_OPENING = 2,
182  	CEPH_MDS_SESSION_OPEN = 3,
183  	CEPH_MDS_SESSION_HUNG = 4,
184  	CEPH_MDS_SESSION_RESTARTING = 5,
185  	CEPH_MDS_SESSION_RECONNECTING = 6,
186  	CEPH_MDS_SESSION_CLOSING = 7,
187  	CEPH_MDS_SESSION_CLOSED = 8,
188  	CEPH_MDS_SESSION_REJECTED = 9,
189  };
190  
191  struct ceph_mds_session {
192  	struct ceph_mds_client *s_mdsc;
193  	int               s_mds;
194  	int               s_state;
195  	unsigned long     s_ttl;      /* time until mds kills us */
196  	unsigned long	  s_features;
197  	u64               s_seq;      /* incoming msg seq # */
198  	struct mutex      s_mutex;    /* serialize session messages */
199  
200  	struct ceph_connection s_con;
201  
202  	struct ceph_auth_handshake s_auth;
203  
204  	atomic_t          s_cap_gen;  /* inc each time we get mds stale msg */
205  	unsigned long     s_cap_ttl;  /* when session caps expire. protected by s_mutex */
206  
207  	/* protected by s_cap_lock */
208  	spinlock_t        s_cap_lock;
209  	refcount_t        s_ref;
210  	struct list_head  s_caps;     /* all caps issued by this session */
211  	struct ceph_cap  *s_cap_iterator;
212  	int               s_nr_caps;
213  	int               s_num_cap_releases;
214  	int		  s_cap_reconnect;
215  	int		  s_readonly;
216  	struct list_head  s_cap_releases; /* waiting cap_release messages */
217  	struct work_struct s_cap_release_work;
218  
219  	/* See ceph_inode_info->i_dirty_item. */
220  	struct list_head  s_cap_dirty;	      /* inodes w/ dirty caps */
221  
222  	/* See ceph_inode_info->i_flushing_item. */
223  	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
224  
225  	unsigned long     s_renew_requested; /* last time we sent a renew req */
226  	u64               s_renew_seq;
227  
228  	struct list_head  s_waiting;  /* waiting requests */
229  	struct list_head  s_unsafe;   /* unsafe requests */
230  	struct xarray	  s_delegated_inos;
231  };
232  
233  /*
234   * modes of choosing which MDS to send a request to
235   */
236  enum {
237  	USE_ANY_MDS,
238  	USE_RANDOM_MDS,
239  	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
240  };
241  
242  struct ceph_mds_request;
243  struct ceph_mds_client;
244  
245  /*
246   * request completion callback
247   */
248  typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
249  					     struct ceph_mds_request *req);
250  /*
251   * wait for request completion callback
252   */
253  typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
254  						 struct ceph_mds_request *req);
255  
256  /*
257   * an in-flight mds request
258   */
259  struct ceph_mds_request {
260  	u64 r_tid;                   /* transaction id */
261  	struct rb_node r_node;
262  	struct ceph_mds_client *r_mdsc;
263  
264  	struct kref       r_kref;
265  	int r_op;                    /* mds op code */
266  
267  	/* operation on what? */
268  	struct inode *r_inode;              /* arg1 */
269  	struct dentry *r_dentry;            /* arg1 */
270  	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
271  	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
272  	char *r_path1, *r_path2;
273  	struct ceph_vino r_ino1, r_ino2;
274  
275  	struct inode *r_parent;		    /* parent dir inode */
276  	struct inode *r_target_inode;       /* resulting inode */
277  	struct inode *r_new_inode;	    /* new inode (for creates) */
278  
279  #define CEPH_MDS_R_DIRECT_IS_HASH	(1) /* r_direct_hash is valid */
280  #define CEPH_MDS_R_ABORTED		(2) /* call was aborted */
281  #define CEPH_MDS_R_GOT_UNSAFE		(3) /* got an unsafe reply */
282  #define CEPH_MDS_R_GOT_SAFE		(4) /* got a safe reply */
283  #define CEPH_MDS_R_GOT_RESULT		(5) /* got a result */
284  #define CEPH_MDS_R_DID_PREPOPULATE	(6) /* prepopulated readdir */
285  #define CEPH_MDS_R_PARENT_LOCKED	(7) /* is r_parent->i_rwsem wlocked? */
286  #define CEPH_MDS_R_ASYNC		(8) /* async request */
287  #define CEPH_MDS_R_FSCRYPT_FILE		(9) /* must marshal fscrypt_file field */
288  	unsigned long	r_req_flags;
289  
290  	struct mutex r_fill_mutex;
291  
292  	union ceph_mds_request_args r_args;
293  
294  	struct ceph_fscrypt_auth *r_fscrypt_auth;
295  	u64	r_fscrypt_file;
296  
297  	u8 *r_altname;		    /* fscrypt binary crypttext for long filenames */
298  	u32 r_altname_len;	    /* length of r_altname */
299  
300  	int r_fmode;        /* file mode, if expecting cap */
301  	int r_request_release_offset;
302  	const struct cred *r_cred;
303  	struct timespec64 r_stamp;
304  
305  	/* for choosing which mds to send this request to */
306  	int r_direct_mode;
307  	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
308  
309  	/* data payload is used for xattr ops */
310  	struct ceph_pagelist *r_pagelist;
311  
312  	/* what caps shall we drop? */
313  	int r_inode_drop, r_inode_unless;
314  	int r_dentry_drop, r_dentry_unless;
315  	int r_old_dentry_drop, r_old_dentry_unless;
316  	struct inode *r_old_inode;
317  	int r_old_inode_drop, r_old_inode_unless;
318  
319  	struct ceph_msg  *r_request;  /* original request */
320  	struct ceph_msg  *r_reply;
321  	struct ceph_mds_reply_info_parsed r_reply_info;
322  	int r_err;
323  	u32               r_readdir_offset;
324  
325  	struct page *r_locked_page;
326  	int r_dir_caps;
327  	int r_num_caps;
328  
329  	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
330  	unsigned long r_started;  /* start time to measure timeout against */
331  	unsigned long r_start_latency;  /* start time to measure latency */
332  	unsigned long r_end_latency;    /* finish time to measure latency */
333  	unsigned long r_request_started; /* start time for mds request only,
334  					    used to measure lease durations */
335  
336  	/* link unsafe requests to parent directory, for fsync */
337  	struct inode	*r_unsafe_dir;
338  	struct list_head r_unsafe_dir_item;
339  
340  	/* unsafe requests that modify the target inode */
341  	struct list_head r_unsafe_target_item;
342  
343  	struct ceph_mds_session *r_session;
344  
345  	int               r_attempts;   /* resend attempts */
346  	int               r_num_fwd;    /* number of forward attempts */
347  	int               r_resend_mds; /* mds to resend to next, if any*/
348  	u32               r_sent_on_mseq; /* cap mseq request was sent at*/
349  	u64		  r_deleg_ino;
350  
351  	struct list_head  r_wait;
352  	struct completion r_completion;
353  	struct completion r_safe_completion;
354  	ceph_mds_request_callback_t r_callback;
355  	struct list_head  r_unsafe_item;  /* per-session unsafe list item */
356  
357  	long long	  r_dir_release_cnt;
358  	long long	  r_dir_ordered_cnt;
359  	int		  r_readdir_cache_idx;
360  
361  	int		  r_feature_needed;
362  
363  	struct ceph_cap_reservation r_caps_reservation;
364  };
365  
366  struct ceph_pool_perm {
367  	struct rb_node node;
368  	int perm;
369  	s64 pool;
370  	size_t pool_ns_len;
371  	char pool_ns[];
372  };
373  
374  struct ceph_snapid_map {
375  	struct rb_node node;
376  	struct list_head lru;
377  	atomic_t ref;
378  	dev_t dev;
379  	u64 snap;
380  	unsigned long last_used;
381  };
382  
383  /*
384   * node for list of quotarealm inodes that are not visible from the filesystem
385   * mountpoint, but required to handle, e.g. quotas.
386   */
387  struct ceph_quotarealm_inode {
388  	struct rb_node node;
389  	u64 ino;
390  	unsigned long timeout; /* last time a lookup failed for this inode */
391  	struct mutex mutex;
392  	struct inode *inode;
393  };
394  
395  struct cap_wait {
396  	struct list_head	list;
397  	u64			ino;
398  	pid_t			tgid;
399  	int			need;
400  	int			want;
401  };
402  
403  enum {
404  	CEPH_MDSC_STOPPING_BEGIN = 1,
405  	CEPH_MDSC_STOPPING_FLUSHING = 2,
406  	CEPH_MDSC_STOPPING_FLUSHED = 3,
407  };
408  
409  /*
410   * mds client state
411   */
412  struct ceph_mds_client {
413  	struct ceph_fs_client  *fsc;
414  	struct mutex            mutex;         /* all nested structures */
415  
416  	struct ceph_mdsmap      *mdsmap;
417  	struct completion       safe_umount_waiters;
418  	wait_queue_head_t       session_close_wq;
419  	struct list_head        waiting_for_map;
420  	int 			mdsmap_err;
421  
422  	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
423  	atomic_t		num_sessions;
424  	int                     max_sessions;  /* len of sessions array */
425  
426  	spinlock_t              stopping_lock;  /* protect snap_empty */
427  	int                     stopping;      /* the stage of shutting down */
428  	atomic_t                stopping_blockers;
429  	struct completion	stopping_waiter;
430  
431  	atomic64_t		quotarealms_count; /* # realms with quota */
432  	/*
433  	 * We keep a list of inodes we don't see in the mountpoint but that we
434  	 * need to track quota realms.
435  	 */
436  	struct rb_root		quotarealms_inodes;
437  	struct mutex		quotarealms_inodes_mutex;
438  
439  	/*
440  	 * snap_rwsem will cover cap linkage into snaprealms, and
441  	 * realm snap contexts.  (later, we can do per-realm snap
442  	 * contexts locks..)  the empty list contains realms with no
443  	 * references (implying they contain no inodes with caps) that
444  	 * should be destroyed.
445  	 */
446  	u64			last_snap_seq;
447  	struct rw_semaphore     snap_rwsem;
448  	struct rb_root          snap_realms;
449  	struct list_head        snap_empty;
450  	int			num_snap_realms;
451  	spinlock_t              snap_empty_lock;  /* protect snap_empty */
452  
453  	u64                    last_tid;      /* most recent mds request */
454  	u64                    oldest_tid;    /* oldest incomplete mds request,
455  						 excluding setfilelock requests */
456  	struct rb_root         request_tree;  /* pending mds requests */
457  	struct delayed_work    delayed_work;  /* delayed work */
458  	unsigned long    last_renew_caps;  /* last time we renewed our caps */
459  	struct list_head cap_delay_list;   /* caps with delayed release */
460  	spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
461  	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
462  	spinlock_t       snap_flush_lock;
463  
464  	u64               last_cap_flush_tid;
465  	struct list_head  cap_flush_list;
466  	struct list_head  cap_dirty_migrating; /* ...that are migration... */
467  	int               num_cap_flushing; /* # caps we are flushing */
468  	spinlock_t        cap_dirty_lock;   /* protects above items */
469  	wait_queue_head_t cap_flushing_wq;
470  
471  	struct work_struct cap_reclaim_work;
472  	atomic_t	   cap_reclaim_pending;
473  
474  	/*
475  	 * Cap reservations
476  	 *
477  	 * Maintain a global pool of preallocated struct ceph_caps, referenced
478  	 * by struct ceph_caps_reservations.  This ensures that we preallocate
479  	 * memory needed to successfully process an MDS response.  (If an MDS
480  	 * sends us cap information and we fail to process it, we will have
481  	 * problems due to the client and MDS being out of sync.)
482  	 *
483  	 * Reservations are 'owned' by a ceph_cap_reservation context.
484  	 */
485  	spinlock_t	caps_list_lock;
486  	struct		list_head caps_list; /* unused (reserved or
487  						unreserved) */
488  	struct		list_head cap_wait_list;
489  	int		caps_total_count;    /* total caps allocated */
490  	int		caps_use_count;      /* in use */
491  	int		caps_use_max;	     /* max used caps */
492  	int		caps_reserve_count;  /* unused, reserved */
493  	int		caps_avail_count;    /* unused, unreserved */
494  	int		caps_min_count;      /* keep at least this many
495  						(unreserved) */
496  	spinlock_t	  dentry_list_lock;
497  	struct list_head  dentry_leases;     /* fifo list */
498  	struct list_head  dentry_dir_leases; /* lru list */
499  
500  	struct ceph_client_metric metric;
501  
502  	spinlock_t		snapid_map_lock;
503  	struct rb_root		snapid_map_tree;
504  	struct list_head	snapid_map_lru;
505  
506  	struct rw_semaphore     pool_perm_rwsem;
507  	struct rb_root		pool_perm_tree;
508  
509  	char nodename[__NEW_UTS_LEN + 1];
510  };
511  
512  extern const char *ceph_mds_op_name(int op);
513  
514  extern bool check_session_state(struct ceph_mds_session *s);
515  void inc_session_sequence(struct ceph_mds_session *s);
516  
517  extern struct ceph_mds_session *
518  __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
519  
520  extern const char *ceph_session_state_name(int s);
521  
522  extern struct ceph_mds_session *
523  ceph_get_mds_session(struct ceph_mds_session *s);
524  extern void ceph_put_mds_session(struct ceph_mds_session *s);
525  
526  extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
527  			     struct ceph_msg *msg, int mds);
528  
529  extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
530  extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
531  extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
532  extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
533  
534  extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
535  
536  extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
537  extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
538  					   struct inode *dir);
539  extern struct ceph_mds_request *
540  ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
541  extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
542  				    struct inode *dir,
543  				    struct ceph_mds_request *req);
544  int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
545  			struct ceph_mds_request *req,
546  			ceph_mds_request_wait_callback_t wait_func);
547  extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
548  				struct inode *dir,
549  				struct ceph_mds_request *req);
550  extern void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req);
551  extern void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req);
ceph_mdsc_get_request(struct ceph_mds_request * req)552  static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
553  {
554  	kref_get(&req->r_kref);
555  }
556  extern void ceph_mdsc_release_request(struct kref *kref);
ceph_mdsc_put_request(struct ceph_mds_request * req)557  static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
558  {
559  	kref_put(&req->r_kref, ceph_mdsc_release_request);
560  }
561  
562  extern void send_flush_mdlog(struct ceph_mds_session *s);
563  extern void ceph_mdsc_iterate_sessions(struct ceph_mds_client *mdsc,
564  				       void (*cb)(struct ceph_mds_session *),
565  				       bool check_state);
566  extern struct ceph_msg *ceph_create_session_msg(u32 op, u64 seq);
567  extern void __ceph_queue_cap_release(struct ceph_mds_session *session,
568  				    struct ceph_cap *cap);
569  extern void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
570  				    struct ceph_mds_session *session);
571  extern void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc);
572  extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
573  extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
574  				     int (*cb)(struct inode *, int mds, void *),
575  				     void *arg);
576  extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
577  
ceph_mdsc_free_path(char * path,int len)578  static inline void ceph_mdsc_free_path(char *path, int len)
579  {
580  	if (!IS_ERR_OR_NULL(path))
581  		__putname(path - (PATH_MAX - 1 - len));
582  }
583  
584  extern char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc,
585  				  struct dentry *dentry, int *plen, u64 *base,
586  				  int for_wire);
587  
588  extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
589  extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
590  				     struct dentry *dentry, char action,
591  				     u32 seq);
592  
593  extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
594  				    struct ceph_msg *msg);
595  extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
596  				   struct ceph_msg *msg);
597  
598  extern struct ceph_mds_session *
599  ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
600  extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
601  					  struct ceph_mds_session *session);
602  
603  extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
604  			  struct ceph_mds_session *session,
605  			  int max_caps);
606  
ceph_wait_on_async_create(struct inode * inode)607  static inline int ceph_wait_on_async_create(struct inode *inode)
608  {
609  	struct ceph_inode_info *ci = ceph_inode(inode);
610  
611  	return wait_on_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT,
612  			   TASK_KILLABLE);
613  }
614  
615  extern int ceph_wait_on_conflict_unlink(struct dentry *dentry);
616  extern u64 ceph_get_deleg_ino(struct ceph_mds_session *session);
617  extern int ceph_restore_deleg_ino(struct ceph_mds_session *session, u64 ino);
618  #endif
619