xref: /openbmc/linux/fs/ceph/mds_client.h (revision 6fa24b41)
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);
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);
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 
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 
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