xref: /linux/fs/ceph/mds_client.h (revision 1553a1c48281243359a9529a10ddb551f3b967ab)
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/auth.h>
18 
19 #include "mdsmap.h"
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 	CEPHFS_FEATURE_NEW_SNAPREALM_INFO,
37 	CEPHFS_FEATURE_HAS_OWNER_UIDGID,
38 
39 	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_HAS_OWNER_UIDGID,
40 };
41 
42 #define CEPHFS_FEATURES_CLIENT_SUPPORTED {	\
43 	0, 1, 2, 3, 4, 5, 6, 7,			\
44 	CEPHFS_FEATURE_MIMIC,			\
45 	CEPHFS_FEATURE_REPLY_ENCODING,		\
46 	CEPHFS_FEATURE_LAZY_CAP_WANTED,		\
47 	CEPHFS_FEATURE_MULTI_RECONNECT,		\
48 	CEPHFS_FEATURE_DELEG_INO,		\
49 	CEPHFS_FEATURE_METRIC_COLLECT,		\
50 	CEPHFS_FEATURE_ALTERNATE_NAME,		\
51 	CEPHFS_FEATURE_NOTIFY_SESSION_STATE,	\
52 	CEPHFS_FEATURE_OP_GETVXATTR,		\
53 	CEPHFS_FEATURE_32BITS_RETRY_FWD,	\
54 	CEPHFS_FEATURE_HAS_OWNER_UIDGID,	\
55 }
56 
57 /*
58  * Some lock dependencies:
59  *
60  * session->s_mutex
61  *         mdsc->mutex
62  *
63  *         mdsc->snap_rwsem
64  *
65  *         ci->i_ceph_lock
66  *                 mdsc->snap_flush_lock
67  *                 mdsc->cap_delay_lock
68  *
69  */
70 
71 struct ceph_fs_client;
72 struct ceph_cap;
73 
74 /*
75  * parsed info about a single inode.  pointers are into the encoded
76  * on-wire structures within the mds reply message payload.
77  */
78 struct ceph_mds_reply_info_in {
79 	struct ceph_mds_reply_inode *in;
80 	struct ceph_dir_layout dir_layout;
81 	u32 symlink_len;
82 	char *symlink;
83 	u32 xattr_len;
84 	char *xattr_data;
85 	u64 inline_version;
86 	u32 inline_len;
87 	char *inline_data;
88 	u32 pool_ns_len;
89 	char *pool_ns_data;
90 	u64 max_bytes;
91 	u64 max_files;
92 	s32 dir_pin;
93 	struct ceph_timespec btime;
94 	struct ceph_timespec snap_btime;
95 	u8 *fscrypt_auth;
96 	u8 *fscrypt_file;
97 	u32 fscrypt_auth_len;
98 	u32 fscrypt_file_len;
99 	u64 rsnaps;
100 	u64 change_attr;
101 };
102 
103 struct ceph_mds_reply_dir_entry {
104 	bool			      is_nokey;
105 	char                          *name;
106 	u32                           name_len;
107 	u32			      raw_hash;
108 	struct ceph_mds_reply_lease   *lease;
109 	struct ceph_mds_reply_info_in inode;
110 	loff_t			      offset;
111 };
112 
113 struct ceph_mds_reply_xattr {
114 	char *xattr_value;
115 	size_t xattr_value_len;
116 };
117 
118 /*
119  * parsed info about an mds reply, including information about
120  * either: 1) the target inode and/or its parent directory and dentry,
121  * and directory contents (for readdir results), or
122  * 2) the file range lock info (for fcntl F_GETLK results).
123  */
124 struct ceph_mds_reply_info_parsed {
125 	struct ceph_mds_reply_head    *head;
126 
127 	/* trace */
128 	struct ceph_mds_reply_info_in diri, targeti;
129 	struct ceph_mds_reply_dirfrag *dirfrag;
130 	char                          *dname;
131 	u8			      *altname;
132 	u32                           dname_len;
133 	u32                           altname_len;
134 	struct ceph_mds_reply_lease   *dlease;
135 	struct ceph_mds_reply_xattr   xattr_info;
136 
137 	/* extra */
138 	union {
139 		/* for fcntl F_GETLK results */
140 		struct ceph_filelock *filelock_reply;
141 
142 		/* for readdir results */
143 		struct {
144 			struct ceph_mds_reply_dirfrag *dir_dir;
145 			size_t			      dir_buf_size;
146 			int                           dir_nr;
147 			bool			      dir_end;
148 			bool			      dir_complete;
149 			bool			      hash_order;
150 			bool			      offset_hash;
151 			struct ceph_mds_reply_dir_entry  *dir_entries;
152 		};
153 
154 		/* for create results */
155 		struct {
156 			bool has_create_ino;
157 			u64 ino;
158 		};
159 	};
160 
161 	/* encoded blob describing snapshot contexts for certain
162 	   operations (e.g., open) */
163 	void *snapblob;
164 	int snapblob_len;
165 };
166 
167 
168 /*
169  * cap releases are batched and sent to the MDS en masse.
170  *
171  * Account for per-message overhead of mds_cap_release header
172  * and __le32 for osd epoch barrier trailing field.
173  */
174 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -		\
175 				sizeof(struct ceph_mds_cap_release)) /	\
176 			        sizeof(struct ceph_mds_cap_item))
177 
178 
179 /*
180  * state associated with each MDS<->client session
181  */
182 enum {
183 	CEPH_MDS_SESSION_NEW = 1,
184 	CEPH_MDS_SESSION_OPENING = 2,
185 	CEPH_MDS_SESSION_OPEN = 3,
186 	CEPH_MDS_SESSION_HUNG = 4,
187 	CEPH_MDS_SESSION_RESTARTING = 5,
188 	CEPH_MDS_SESSION_RECONNECTING = 6,
189 	CEPH_MDS_SESSION_CLOSING = 7,
190 	CEPH_MDS_SESSION_CLOSED = 8,
191 	CEPH_MDS_SESSION_REJECTED = 9,
192 };
193 
194 struct ceph_mds_session {
195 	struct ceph_mds_client *s_mdsc;
196 	int               s_mds;
197 	int               s_state;
198 	unsigned long     s_ttl;      /* time until mds kills us */
199 	unsigned long	  s_features;
200 	u64               s_seq;      /* incoming msg seq # */
201 	struct mutex      s_mutex;    /* serialize session messages */
202 
203 	struct ceph_connection s_con;
204 
205 	struct ceph_auth_handshake s_auth;
206 
207 	atomic_t          s_cap_gen;  /* inc each time we get mds stale msg */
208 	unsigned long     s_cap_ttl;  /* when session caps expire. protected by s_mutex */
209 
210 	/* protected by s_cap_lock */
211 	spinlock_t        s_cap_lock;
212 	refcount_t        s_ref;
213 	struct list_head  s_caps;     /* all caps issued by this session */
214 	struct ceph_cap  *s_cap_iterator;
215 	int               s_nr_caps;
216 	int               s_num_cap_releases;
217 	int		  s_cap_reconnect;
218 	int		  s_readonly;
219 	struct list_head  s_cap_releases; /* waiting cap_release messages */
220 	struct work_struct s_cap_release_work;
221 
222 	/* See ceph_inode_info->i_dirty_item. */
223 	struct list_head  s_cap_dirty;	      /* inodes w/ dirty caps */
224 
225 	/* See ceph_inode_info->i_flushing_item. */
226 	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
227 
228 	unsigned long     s_renew_requested; /* last time we sent a renew req */
229 	u64               s_renew_seq;
230 
231 	struct list_head  s_waiting;  /* waiting requests */
232 	struct list_head  s_unsafe;   /* unsafe requests */
233 	struct xarray	  s_delegated_inos;
234 };
235 
236 /*
237  * modes of choosing which MDS to send a request to
238  */
239 enum {
240 	USE_ANY_MDS,
241 	USE_RANDOM_MDS,
242 	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
243 };
244 
245 struct ceph_mds_request;
246 struct ceph_mds_client;
247 
248 /*
249  * request completion callback
250  */
251 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
252 					     struct ceph_mds_request *req);
253 /*
254  * wait for request completion callback
255  */
256 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
257 						 struct ceph_mds_request *req);
258 
259 /*
260  * an in-flight mds request
261  */
262 struct ceph_mds_request {
263 	u64 r_tid;                   /* transaction id */
264 	struct rb_node r_node;
265 	struct ceph_mds_client *r_mdsc;
266 
267 	struct kref       r_kref;
268 	int r_op;                    /* mds op code */
269 
270 	/* operation on what? */
271 	struct inode *r_inode;              /* arg1 */
272 	struct dentry *r_dentry;            /* arg1 */
273 	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
274 	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
275 	char *r_path1, *r_path2;
276 	struct ceph_vino r_ino1, r_ino2;
277 
278 	struct inode *r_parent;		    /* parent dir inode */
279 	struct inode *r_target_inode;       /* resulting inode */
280 	struct inode *r_new_inode;	    /* new inode (for creates) */
281 
282 #define CEPH_MDS_R_DIRECT_IS_HASH	(1) /* r_direct_hash is valid */
283 #define CEPH_MDS_R_ABORTED		(2) /* call was aborted */
284 #define CEPH_MDS_R_GOT_UNSAFE		(3) /* got an unsafe reply */
285 #define CEPH_MDS_R_GOT_SAFE		(4) /* got a safe reply */
286 #define CEPH_MDS_R_GOT_RESULT		(5) /* got a result */
287 #define CEPH_MDS_R_DID_PREPOPULATE	(6) /* prepopulated readdir */
288 #define CEPH_MDS_R_PARENT_LOCKED	(7) /* is r_parent->i_rwsem wlocked? */
289 #define CEPH_MDS_R_ASYNC		(8) /* async request */
290 #define CEPH_MDS_R_FSCRYPT_FILE		(9) /* must marshal fscrypt_file field */
291 	unsigned long	r_req_flags;
292 
293 	struct mutex r_fill_mutex;
294 
295 	union ceph_mds_request_args r_args;
296 
297 	struct ceph_fscrypt_auth *r_fscrypt_auth;
298 	u64	r_fscrypt_file;
299 
300 	u8 *r_altname;		    /* fscrypt binary crypttext for long filenames */
301 	u32 r_altname_len;	    /* length of r_altname */
302 
303 	int r_fmode;        /* file mode, if expecting cap */
304 	int r_request_release_offset;
305 	const struct cred *r_cred;
306 	struct mnt_idmap *r_mnt_idmap;
307 	struct timespec64 r_stamp;
308 
309 	/* for choosing which mds to send this request to */
310 	int r_direct_mode;
311 	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
312 
313 	/* data payload is used for xattr ops */
314 	struct ceph_pagelist *r_pagelist;
315 
316 	/* what caps shall we drop? */
317 	int r_inode_drop, r_inode_unless;
318 	int r_dentry_drop, r_dentry_unless;
319 	int r_old_dentry_drop, r_old_dentry_unless;
320 	struct inode *r_old_inode;
321 	int r_old_inode_drop, r_old_inode_unless;
322 
323 	struct ceph_msg  *r_request;  /* original request */
324 	struct ceph_msg  *r_reply;
325 	struct ceph_mds_reply_info_parsed r_reply_info;
326 	int r_err;
327 	u32               r_readdir_offset;
328 
329 	struct page *r_locked_page;
330 	int r_dir_caps;
331 	int r_num_caps;
332 
333 	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
334 	unsigned long r_started;  /* start time to measure timeout against */
335 	unsigned long r_start_latency;  /* start time to measure latency */
336 	unsigned long r_end_latency;    /* finish time to measure latency */
337 	unsigned long r_request_started; /* start time for mds request only,
338 					    used to measure lease durations */
339 
340 	/* link unsafe requests to parent directory, for fsync */
341 	struct inode	*r_unsafe_dir;
342 	struct list_head r_unsafe_dir_item;
343 
344 	/* unsafe requests that modify the target inode */
345 	struct list_head r_unsafe_target_item;
346 
347 	struct ceph_mds_session *r_session;
348 
349 	int               r_attempts;   /* resend attempts */
350 	int               r_num_fwd;    /* number of forward attempts */
351 	int               r_resend_mds; /* mds to resend to next, if any*/
352 	u32               r_sent_on_mseq; /* cap mseq request was sent at*/
353 	u64		  r_deleg_ino;
354 
355 	struct list_head  r_wait;
356 	struct completion r_completion;
357 	struct completion r_safe_completion;
358 	ceph_mds_request_callback_t r_callback;
359 	struct list_head  r_unsafe_item;  /* per-session unsafe list item */
360 
361 	long long	  r_dir_release_cnt;
362 	long long	  r_dir_ordered_cnt;
363 	int		  r_readdir_cache_idx;
364 
365 	int		  r_feature_needed;
366 
367 	struct ceph_cap_reservation r_caps_reservation;
368 };
369 
370 struct ceph_pool_perm {
371 	struct rb_node node;
372 	int perm;
373 	s64 pool;
374 	size_t pool_ns_len;
375 	char pool_ns[];
376 };
377 
378 struct ceph_snapid_map {
379 	struct rb_node node;
380 	struct list_head lru;
381 	atomic_t ref;
382 	dev_t dev;
383 	u64 snap;
384 	unsigned long last_used;
385 };
386 
387 /*
388  * node for list of quotarealm inodes that are not visible from the filesystem
389  * mountpoint, but required to handle, e.g. quotas.
390  */
391 struct ceph_quotarealm_inode {
392 	struct rb_node node;
393 	u64 ino;
394 	unsigned long timeout; /* last time a lookup failed for this inode */
395 	struct mutex mutex;
396 	struct inode *inode;
397 };
398 
399 struct cap_wait {
400 	struct list_head	list;
401 	u64			ino;
402 	pid_t			tgid;
403 	int			need;
404 	int			want;
405 };
406 
407 enum {
408 	CEPH_MDSC_STOPPING_BEGIN = 1,
409 	CEPH_MDSC_STOPPING_FLUSHING = 2,
410 	CEPH_MDSC_STOPPING_FLUSHED = 3,
411 };
412 
413 /*
414  * mds client state
415  */
416 struct ceph_mds_client {
417 	struct ceph_fs_client  *fsc;
418 	struct mutex            mutex;         /* all nested structures */
419 
420 	struct ceph_mdsmap      *mdsmap;
421 	struct completion       safe_umount_waiters;
422 	wait_queue_head_t       session_close_wq;
423 	struct list_head        waiting_for_map;
424 	int 			mdsmap_err;
425 
426 	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
427 	atomic_t		num_sessions;
428 	int                     max_sessions;  /* len of sessions array */
429 
430 	spinlock_t              stopping_lock;  /* protect snap_empty */
431 	int                     stopping;      /* the stage of shutting down */
432 	atomic_t                stopping_blockers;
433 	struct completion	stopping_waiter;
434 
435 	atomic64_t		quotarealms_count; /* # realms with quota */
436 	/*
437 	 * We keep a list of inodes we don't see in the mountpoint but that we
438 	 * need to track quota realms.
439 	 */
440 	struct rb_root		quotarealms_inodes;
441 	struct mutex		quotarealms_inodes_mutex;
442 
443 	/*
444 	 * snap_rwsem will cover cap linkage into snaprealms, and
445 	 * realm snap contexts.  (later, we can do per-realm snap
446 	 * contexts locks..)  the empty list contains realms with no
447 	 * references (implying they contain no inodes with caps) that
448 	 * should be destroyed.
449 	 */
450 	u64			last_snap_seq;
451 	struct rw_semaphore     snap_rwsem;
452 	struct rb_root          snap_realms;
453 	struct list_head        snap_empty;
454 	int			num_snap_realms;
455 	spinlock_t              snap_empty_lock;  /* protect snap_empty */
456 
457 	u64                    last_tid;      /* most recent mds request */
458 	u64                    oldest_tid;    /* oldest incomplete mds request,
459 						 excluding setfilelock requests */
460 	struct rb_root         request_tree;  /* pending mds requests */
461 	struct delayed_work    delayed_work;  /* delayed work */
462 	unsigned long    last_renew_caps;  /* last time we renewed our caps */
463 	struct list_head cap_delay_list;   /* caps with delayed release */
464 	spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
465 	struct list_head cap_unlink_delay_list;  /* caps with delayed release for unlink */
466 	spinlock_t       cap_unlink_delay_lock;  /* protects cap_unlink_delay_list */
467 	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
468 	spinlock_t       snap_flush_lock;
469 
470 	u64               last_cap_flush_tid;
471 	struct list_head  cap_flush_list;
472 	struct list_head  cap_dirty_migrating; /* ...that are migration... */
473 	int               num_cap_flushing; /* # caps we are flushing */
474 	spinlock_t        cap_dirty_lock;   /* protects above items */
475 	wait_queue_head_t cap_flushing_wq;
476 
477 	struct work_struct cap_reclaim_work;
478 	atomic_t	   cap_reclaim_pending;
479 
480 	struct work_struct cap_unlink_work;
481 
482 	/*
483 	 * Cap reservations
484 	 *
485 	 * Maintain a global pool of preallocated struct ceph_caps, referenced
486 	 * by struct ceph_caps_reservations.  This ensures that we preallocate
487 	 * memory needed to successfully process an MDS response.  (If an MDS
488 	 * sends us cap information and we fail to process it, we will have
489 	 * problems due to the client and MDS being out of sync.)
490 	 *
491 	 * Reservations are 'owned' by a ceph_cap_reservation context.
492 	 */
493 	spinlock_t	caps_list_lock;
494 	struct		list_head caps_list; /* unused (reserved or
495 						unreserved) */
496 	struct		list_head cap_wait_list;
497 	int		caps_total_count;    /* total caps allocated */
498 	int		caps_use_count;      /* in use */
499 	int		caps_use_max;	     /* max used caps */
500 	int		caps_reserve_count;  /* unused, reserved */
501 	int		caps_avail_count;    /* unused, unreserved */
502 	int		caps_min_count;      /* keep at least this many
503 						(unreserved) */
504 	spinlock_t	  dentry_list_lock;
505 	struct list_head  dentry_leases;     /* fifo list */
506 	struct list_head  dentry_dir_leases; /* lru list */
507 
508 	struct ceph_client_metric metric;
509 
510 	spinlock_t		snapid_map_lock;
511 	struct rb_root		snapid_map_tree;
512 	struct list_head	snapid_map_lru;
513 
514 	struct rw_semaphore     pool_perm_rwsem;
515 	struct rb_root		pool_perm_tree;
516 
517 	char nodename[__NEW_UTS_LEN + 1];
518 };
519 
520 extern const char *ceph_mds_op_name(int op);
521 
522 extern bool check_session_state(struct ceph_mds_session *s);
523 void inc_session_sequence(struct ceph_mds_session *s);
524 
525 extern struct ceph_mds_session *
526 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
527 
528 extern const char *ceph_session_state_name(int s);
529 
530 extern struct ceph_mds_session *
531 ceph_get_mds_session(struct ceph_mds_session *s);
532 extern void ceph_put_mds_session(struct ceph_mds_session *s);
533 
534 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
535 			     struct ceph_msg *msg, int mds);
536 
537 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
538 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
539 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
540 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
541 
542 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
543 
544 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
545 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
546 					   struct inode *dir);
547 extern struct ceph_mds_request *
548 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
549 extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
550 				    struct inode *dir,
551 				    struct ceph_mds_request *req);
552 int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
553 			struct ceph_mds_request *req,
554 			ceph_mds_request_wait_callback_t wait_func);
555 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
556 				struct inode *dir,
557 				struct ceph_mds_request *req);
558 extern void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req);
559 extern void ceph_mdsc_release_dir_caps_async(struct ceph_mds_request *req);
560 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
561 {
562 	kref_get(&req->r_kref);
563 }
564 extern void ceph_mdsc_release_request(struct kref *kref);
565 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
566 {
567 	kref_put(&req->r_kref, ceph_mdsc_release_request);
568 }
569 
570 extern void send_flush_mdlog(struct ceph_mds_session *s);
571 extern void ceph_mdsc_iterate_sessions(struct ceph_mds_client *mdsc,
572 				       void (*cb)(struct ceph_mds_session *),
573 				       bool check_state);
574 extern struct ceph_msg *ceph_create_session_msg(u32 op, u64 seq);
575 extern void __ceph_queue_cap_release(struct ceph_mds_session *session,
576 				    struct ceph_cap *cap);
577 extern void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
578 				    struct ceph_mds_session *session);
579 extern void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc);
580 extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
581 extern void ceph_queue_cap_unlink_work(struct ceph_mds_client *mdsc);
582 extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
583 				     int (*cb)(struct inode *, int mds, void *),
584 				     void *arg);
585 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
586 
587 static inline void ceph_mdsc_free_path(char *path, int len)
588 {
589 	if (!IS_ERR_OR_NULL(path))
590 		__putname(path - (PATH_MAX - 1 - len));
591 }
592 
593 extern char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc,
594 				  struct dentry *dentry, int *plen, u64 *base,
595 				  int for_wire);
596 
597 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
598 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
599 				     struct dentry *dentry, char action,
600 				     u32 seq);
601 
602 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
603 				    struct ceph_msg *msg);
604 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
605 				   struct ceph_msg *msg);
606 
607 extern struct ceph_mds_session *
608 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
609 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
610 					  struct ceph_mds_session *session);
611 
612 extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
613 			  struct ceph_mds_session *session,
614 			  int max_caps);
615 
616 static inline int ceph_wait_on_async_create(struct inode *inode)
617 {
618 	struct ceph_inode_info *ci = ceph_inode(inode);
619 
620 	return wait_on_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT,
621 			   TASK_KILLABLE);
622 }
623 
624 extern int ceph_wait_on_conflict_unlink(struct dentry *dentry);
625 extern u64 ceph_get_deleg_ino(struct ceph_mds_session *session);
626 extern int ceph_restore_deleg_ino(struct ceph_mds_session *session, u64 ino);
627 
628 extern bool enable_unsafe_idmap;
629 #endif
630