xref: /linux/fs/ceph/mds_client.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,
39 
40 	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,
41 };
42 
43 #define CEPHFS_FEATURES_CLIENT_SUPPORTED {	\
44 	0, 1, 2, 3, 4, 5, 6, 7,			\
45 	CEPHFS_FEATURE_MIMIC,			\
46 	CEPHFS_FEATURE_REPLY_ENCODING,		\
47 	CEPHFS_FEATURE_LAZY_CAP_WANTED,		\
48 	CEPHFS_FEATURE_MULTI_RECONNECT,		\
49 	CEPHFS_FEATURE_DELEG_INO,		\
50 	CEPHFS_FEATURE_METRIC_COLLECT,		\
51 	CEPHFS_FEATURE_ALTERNATE_NAME,		\
52 	CEPHFS_FEATURE_NOTIFY_SESSION_STATE,	\
53 	CEPHFS_FEATURE_OP_GETVXATTR,		\
54 	CEPHFS_FEATURE_32BITS_RETRY_FWD,	\
55 	CEPHFS_FEATURE_HAS_OWNER_UIDGID,	\
56 	CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK,	\
57 }
58 
59 /*
60  * Some lock dependencies:
61  *
62  * session->s_mutex
63  *         mdsc->mutex
64  *
65  *         mdsc->snap_rwsem
66  *
67  *         ci->i_ceph_lock
68  *                 mdsc->snap_flush_lock
69  *                 mdsc->cap_delay_lock
70  *
71  */
72 
73 struct ceph_fs_client;
74 struct ceph_cap;
75 
76 #define MDS_AUTH_UID_ANY -1
77 
78 struct ceph_mds_cap_match {
79 	s64 uid;  /* default to MDS_AUTH_UID_ANY */
80 	u32 num_gids;
81 	u32 *gids;  /* use these GIDs */
82 	char *path;  /* require path to be child of this
83 			(may be "" or "/" for any) */
84 	char *fs_name;
85 	bool root_squash;  /* default to false */
86 };
87 
88 struct ceph_mds_cap_auth {
89 	struct ceph_mds_cap_match match;
90 	bool readable;
91 	bool writeable;
92 };
93 
94 /*
95  * parsed info about a single inode.  pointers are into the encoded
96  * on-wire structures within the mds reply message payload.
97  */
98 struct ceph_mds_reply_info_in {
99 	struct ceph_mds_reply_inode *in;
100 	struct ceph_dir_layout dir_layout;
101 	u32 symlink_len;
102 	char *symlink;
103 	u32 xattr_len;
104 	char *xattr_data;
105 	u64 inline_version;
106 	u32 inline_len;
107 	char *inline_data;
108 	u32 pool_ns_len;
109 	char *pool_ns_data;
110 	u64 max_bytes;
111 	u64 max_files;
112 	s32 dir_pin;
113 	struct ceph_timespec btime;
114 	struct ceph_timespec snap_btime;
115 	u8 *fscrypt_auth;
116 	u8 *fscrypt_file;
117 	u32 fscrypt_auth_len;
118 	u32 fscrypt_file_len;
119 	u64 rsnaps;
120 	u64 change_attr;
121 };
122 
123 struct ceph_mds_reply_dir_entry {
124 	bool			      is_nokey;
125 	char                          *name;
126 	u32                           name_len;
127 	u32			      raw_hash;
128 	struct ceph_mds_reply_lease   *lease;
129 	struct ceph_mds_reply_info_in inode;
130 	loff_t			      offset;
131 };
132 
133 struct ceph_mds_reply_xattr {
134 	char *xattr_value;
135 	size_t xattr_value_len;
136 };
137 
138 /*
139  * parsed info about an mds reply, including information about
140  * either: 1) the target inode and/or its parent directory and dentry,
141  * and directory contents (for readdir results), or
142  * 2) the file range lock info (for fcntl F_GETLK results).
143  */
144 struct ceph_mds_reply_info_parsed {
145 	struct ceph_mds_reply_head    *head;
146 
147 	/* trace */
148 	struct ceph_mds_reply_info_in diri, targeti;
149 	struct ceph_mds_reply_dirfrag *dirfrag;
150 	char                          *dname;
151 	u8			      *altname;
152 	u32                           dname_len;
153 	u32                           altname_len;
154 	struct ceph_mds_reply_lease   *dlease;
155 	struct ceph_mds_reply_xattr   xattr_info;
156 
157 	/* extra */
158 	union {
159 		/* for fcntl F_GETLK results */
160 		struct ceph_filelock *filelock_reply;
161 
162 		/* for readdir results */
163 		struct {
164 			struct ceph_mds_reply_dirfrag *dir_dir;
165 			size_t			      dir_buf_size;
166 			int                           dir_nr;
167 			bool			      dir_end;
168 			bool			      dir_complete;
169 			bool			      hash_order;
170 			bool			      offset_hash;
171 			struct ceph_mds_reply_dir_entry  *dir_entries;
172 		};
173 
174 		/* for create results */
175 		struct {
176 			bool has_create_ino;
177 			u64 ino;
178 		};
179 	};
180 
181 	/* encoded blob describing snapshot contexts for certain
182 	   operations (e.g., open) */
183 	void *snapblob;
184 	int snapblob_len;
185 };
186 
187 
188 /*
189  * cap releases are batched and sent to the MDS en masse.
190  *
191  * Account for per-message overhead of mds_cap_release header
192  * and __le32 for osd epoch barrier trailing field.
193  */
194 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -		\
195 				sizeof(struct ceph_mds_cap_release)) /	\
196 			        sizeof(struct ceph_mds_cap_item))
197 
198 
199 /*
200  * state associated with each MDS<->client session
201  */
202 enum {
203 	CEPH_MDS_SESSION_NEW = 1,
204 	CEPH_MDS_SESSION_OPENING = 2,
205 	CEPH_MDS_SESSION_OPEN = 3,
206 	CEPH_MDS_SESSION_HUNG = 4,
207 	CEPH_MDS_SESSION_RESTARTING = 5,
208 	CEPH_MDS_SESSION_RECONNECTING = 6,
209 	CEPH_MDS_SESSION_CLOSING = 7,
210 	CEPH_MDS_SESSION_CLOSED = 8,
211 	CEPH_MDS_SESSION_REJECTED = 9,
212 };
213 
214 struct ceph_mds_session {
215 	struct ceph_mds_client *s_mdsc;
216 	int               s_mds;
217 	int               s_state;
218 	unsigned long     s_ttl;      /* time until mds kills us */
219 	unsigned long	  s_features;
220 	u64               s_seq;      /* incoming msg seq # */
221 	struct mutex      s_mutex;    /* serialize session messages */
222 
223 	struct ceph_connection s_con;
224 
225 	struct ceph_auth_handshake s_auth;
226 
227 	atomic_t          s_cap_gen;  /* inc each time we get mds stale msg */
228 	unsigned long     s_cap_ttl;  /* when session caps expire. protected by s_mutex */
229 
230 	/* protected by s_cap_lock */
231 	spinlock_t        s_cap_lock;
232 	refcount_t        s_ref;
233 	struct list_head  s_caps;     /* all caps issued by this session */
234 	struct ceph_cap  *s_cap_iterator;
235 	int               s_nr_caps;
236 	int               s_num_cap_releases;
237 	int		  s_cap_reconnect;
238 	int		  s_readonly;
239 	struct list_head  s_cap_releases; /* waiting cap_release messages */
240 	struct work_struct s_cap_release_work;
241 
242 	/* See ceph_inode_info->i_dirty_item. */
243 	struct list_head  s_cap_dirty;	      /* inodes w/ dirty caps */
244 
245 	/* See ceph_inode_info->i_flushing_item. */
246 	struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
247 
248 	unsigned long     s_renew_requested; /* last time we sent a renew req */
249 	u64               s_renew_seq;
250 
251 	struct list_head  s_waiting;  /* waiting requests */
252 	struct list_head  s_unsafe;   /* unsafe requests */
253 	struct xarray	  s_delegated_inos;
254 };
255 
256 /*
257  * modes of choosing which MDS to send a request to
258  */
259 enum {
260 	USE_ANY_MDS,
261 	USE_RANDOM_MDS,
262 	USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
263 };
264 
265 struct ceph_mds_request;
266 struct ceph_mds_client;
267 
268 /*
269  * request completion callback
270  */
271 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
272 					     struct ceph_mds_request *req);
273 /*
274  * wait for request completion callback
275  */
276 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
277 						 struct ceph_mds_request *req);
278 
279 /*
280  * an in-flight mds request
281  */
282 struct ceph_mds_request {
283 	u64 r_tid;                   /* transaction id */
284 	struct rb_node r_node;
285 	struct ceph_mds_client *r_mdsc;
286 
287 	struct kref       r_kref;
288 	int r_op;                    /* mds op code */
289 
290 	/* operation on what? */
291 	struct inode *r_inode;              /* arg1 */
292 	struct dentry *r_dentry;            /* arg1 */
293 	struct dentry *r_old_dentry;        /* arg2: rename from or link from */
294 	struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
295 	char *r_path1, *r_path2;
296 	struct ceph_vino r_ino1, r_ino2;
297 
298 	struct inode *r_parent;		    /* parent dir inode */
299 	struct inode *r_target_inode;       /* resulting inode */
300 	struct inode *r_new_inode;	    /* new inode (for creates) */
301 
302 #define CEPH_MDS_R_DIRECT_IS_HASH	(1) /* r_direct_hash is valid */
303 #define CEPH_MDS_R_ABORTED		(2) /* call was aborted */
304 #define CEPH_MDS_R_GOT_UNSAFE		(3) /* got an unsafe reply */
305 #define CEPH_MDS_R_GOT_SAFE		(4) /* got a safe reply */
306 #define CEPH_MDS_R_GOT_RESULT		(5) /* got a result */
307 #define CEPH_MDS_R_DID_PREPOPULATE	(6) /* prepopulated readdir */
308 #define CEPH_MDS_R_PARENT_LOCKED	(7) /* is r_parent->i_rwsem wlocked? */
309 #define CEPH_MDS_R_ASYNC		(8) /* async request */
310 #define CEPH_MDS_R_FSCRYPT_FILE		(9) /* must marshal fscrypt_file field */
311 	unsigned long	r_req_flags;
312 
313 	struct mutex r_fill_mutex;
314 
315 	union ceph_mds_request_args r_args;
316 
317 	struct ceph_fscrypt_auth *r_fscrypt_auth;
318 	u64	r_fscrypt_file;
319 
320 	u8 *r_altname;		    /* fscrypt binary crypttext for long filenames */
321 	u32 r_altname_len;	    /* length of r_altname */
322 
323 	int r_fmode;        /* file mode, if expecting cap */
324 	int r_request_release_offset;
325 	const struct cred *r_cred;
326 	struct mnt_idmap *r_mnt_idmap;
327 	struct timespec64 r_stamp;
328 
329 	/* for choosing which mds to send this request to */
330 	int r_direct_mode;
331 	u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
332 
333 	/* data payload is used for xattr ops */
334 	struct ceph_pagelist *r_pagelist;
335 
336 	/* what caps shall we drop? */
337 	int r_inode_drop, r_inode_unless;
338 	int r_dentry_drop, r_dentry_unless;
339 	int r_old_dentry_drop, r_old_dentry_unless;
340 	struct inode *r_old_inode;
341 	int r_old_inode_drop, r_old_inode_unless;
342 
343 	struct ceph_msg  *r_request;  /* original request */
344 	struct ceph_msg  *r_reply;
345 	struct ceph_mds_reply_info_parsed r_reply_info;
346 	int r_err;
347 	u32               r_readdir_offset;
348 
349 	struct page *r_locked_page;
350 	int r_dir_caps;
351 	int r_num_caps;
352 
353 	unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
354 	unsigned long r_started;  /* start time to measure timeout against */
355 	unsigned long r_start_latency;  /* start time to measure latency */
356 	unsigned long r_end_latency;    /* finish time to measure latency */
357 	unsigned long r_request_started; /* start time for mds request only,
358 					    used to measure lease durations */
359 
360 	/* link unsafe requests to parent directory, for fsync */
361 	struct inode	*r_unsafe_dir;
362 	struct list_head r_unsafe_dir_item;
363 
364 	/* unsafe requests that modify the target inode */
365 	struct list_head r_unsafe_target_item;
366 
367 	struct ceph_mds_session *r_session;
368 
369 	int               r_attempts;   /* resend attempts */
370 	int               r_num_fwd;    /* number of forward attempts */
371 	int               r_resend_mds; /* mds to resend to next, if any*/
372 	u32               r_sent_on_mseq; /* cap mseq request was sent at*/
373 	u64		  r_deleg_ino;
374 
375 	struct list_head  r_wait;
376 	struct completion r_completion;
377 	struct completion r_safe_completion;
378 	ceph_mds_request_callback_t r_callback;
379 	struct list_head  r_unsafe_item;  /* per-session unsafe list item */
380 
381 	long long	  r_dir_release_cnt;
382 	long long	  r_dir_ordered_cnt;
383 	int		  r_readdir_cache_idx;
384 
385 	int		  r_feature_needed;
386 
387 	struct ceph_cap_reservation r_caps_reservation;
388 };
389 
390 struct ceph_pool_perm {
391 	struct rb_node node;
392 	int perm;
393 	s64 pool;
394 	size_t pool_ns_len;
395 	char pool_ns[];
396 };
397 
398 struct ceph_snapid_map {
399 	struct rb_node node;
400 	struct list_head lru;
401 	atomic_t ref;
402 	dev_t dev;
403 	u64 snap;
404 	unsigned long last_used;
405 };
406 
407 /*
408  * node for list of quotarealm inodes that are not visible from the filesystem
409  * mountpoint, but required to handle, e.g. quotas.
410  */
411 struct ceph_quotarealm_inode {
412 	struct rb_node node;
413 	u64 ino;
414 	unsigned long timeout; /* last time a lookup failed for this inode */
415 	struct mutex mutex;
416 	struct inode *inode;
417 };
418 
419 #ifdef CONFIG_DEBUG_FS
420 
421 struct cap_wait {
422 	struct list_head	list;
423 	u64			ino;
424 	pid_t			tgid;
425 	int			need;
426 	int			want;
427 };
428 
429 #endif
430 
431 enum {
432 	CEPH_MDSC_STOPPING_BEGIN = 1,
433 	CEPH_MDSC_STOPPING_FLUSHING = 2,
434 	CEPH_MDSC_STOPPING_FLUSHED = 3,
435 };
436 
437 /*
438  * mds client state
439  */
440 struct ceph_mds_client {
441 	struct ceph_fs_client  *fsc;
442 	struct mutex            mutex;         /* all nested structures */
443 
444 	struct ceph_mdsmap      *mdsmap;
445 	struct completion       safe_umount_waiters;
446 	wait_queue_head_t       session_close_wq;
447 	struct list_head        waiting_for_map;
448 	int 			mdsmap_err;
449 
450 	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
451 	atomic_t		num_sessions;
452 	int                     max_sessions;  /* len of sessions array */
453 
454 	spinlock_t              stopping_lock;  /* protect snap_empty */
455 	int                     stopping;      /* the stage of shutting down */
456 	atomic_t                stopping_blockers;
457 	struct completion	stopping_waiter;
458 
459 	atomic64_t		quotarealms_count; /* # realms with quota */
460 	/*
461 	 * We keep a list of inodes we don't see in the mountpoint but that we
462 	 * need to track quota realms.
463 	 */
464 	struct rb_root		quotarealms_inodes;
465 	struct mutex		quotarealms_inodes_mutex;
466 
467 	/*
468 	 * snap_rwsem will cover cap linkage into snaprealms, and
469 	 * realm snap contexts.  (later, we can do per-realm snap
470 	 * contexts locks..)  the empty list contains realms with no
471 	 * references (implying they contain no inodes with caps) that
472 	 * should be destroyed.
473 	 */
474 	u64			last_snap_seq;
475 	struct rw_semaphore     snap_rwsem;
476 	struct rb_root          snap_realms;
477 	struct list_head        snap_empty;
478 	int			num_snap_realms;
479 	spinlock_t              snap_empty_lock;  /* protect snap_empty */
480 
481 	u64                    last_tid;      /* most recent mds request */
482 	u64                    oldest_tid;    /* oldest incomplete mds request,
483 						 excluding setfilelock requests */
484 	struct rb_root         request_tree;  /* pending mds requests */
485 	struct delayed_work    delayed_work;  /* delayed work */
486 	unsigned long    last_renew_caps;  /* last time we renewed our caps */
487 	struct list_head cap_delay_list;   /* caps with delayed release */
488 	struct list_head cap_unlink_delay_list;  /* caps with delayed release for unlink */
489 	spinlock_t       cap_delay_lock;   /* protects cap_delay_list and cap_unlink_delay_list */
490 	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
491 	spinlock_t       snap_flush_lock;
492 
493 	u64               last_cap_flush_tid;
494 	struct list_head  cap_flush_list;
495 	struct list_head  cap_dirty_migrating; /* ...that are migration... */
496 	int               num_cap_flushing; /* # caps we are flushing */
497 	spinlock_t        cap_dirty_lock;   /* protects above items */
498 	wait_queue_head_t cap_flushing_wq;
499 
500 	struct work_struct cap_reclaim_work;
501 	atomic_t	   cap_reclaim_pending;
502 
503 	struct work_struct cap_unlink_work;
504 
505 	/*
506 	 * Cap reservations
507 	 *
508 	 * Maintain a global pool of preallocated struct ceph_caps, referenced
509 	 * by struct ceph_caps_reservations.  This ensures that we preallocate
510 	 * memory needed to successfully process an MDS response.  (If an MDS
511 	 * sends us cap information and we fail to process it, we will have
512 	 * problems due to the client and MDS being out of sync.)
513 	 *
514 	 * Reservations are 'owned' by a ceph_cap_reservation context.
515 	 */
516 	spinlock_t	caps_list_lock;
517 	struct		list_head caps_list; /* unused (reserved or
518 						unreserved) */
519 #ifdef CONFIG_DEBUG_FS
520 	struct		list_head cap_wait_list;
521 #endif
522 	int		caps_total_count;    /* total caps allocated */
523 	int		caps_use_count;      /* in use */
524 	int		caps_use_max;	     /* max used caps */
525 	int		caps_reserve_count;  /* unused, reserved */
526 	int		caps_avail_count;    /* unused, unreserved */
527 	int		caps_min_count;      /* keep at least this many
528 						(unreserved) */
529 	spinlock_t	  dentry_list_lock;
530 	struct list_head  dentry_leases;     /* fifo list */
531 	struct list_head  dentry_dir_leases; /* lru list */
532 
533 	struct ceph_client_metric metric;
534 
535 	spinlock_t		snapid_map_lock;
536 	struct rb_root		snapid_map_tree;
537 	struct list_head	snapid_map_lru;
538 
539 	struct rw_semaphore     pool_perm_rwsem;
540 	struct rb_root		pool_perm_tree;
541 
542 	u32			 s_cap_auths_num;
543 	struct ceph_mds_cap_auth *s_cap_auths;
544 
545 	char nodename[__NEW_UTS_LEN + 1];
546 };
547 
548 extern const char *ceph_mds_op_name(int op);
549 
550 extern bool check_session_state(struct ceph_mds_session *s);
551 void inc_session_sequence(struct ceph_mds_session *s);
552 
553 extern struct ceph_mds_session *
554 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
555 
556 extern const char *ceph_session_state_name(int s);
557 
558 extern struct ceph_mds_session *
559 ceph_get_mds_session(struct ceph_mds_session *s);
560 extern void ceph_put_mds_session(struct ceph_mds_session *s);
561 
562 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
563 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
564 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
565 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
566 
567 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
568 
569 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
570 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
571 					   struct inode *dir);
572 extern struct ceph_mds_request *
573 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
574 extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
575 				    struct inode *dir,
576 				    struct ceph_mds_request *req);
577 int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
578 			struct ceph_mds_request *req,
579 			ceph_mds_request_wait_callback_t wait_func);
580 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
581 				struct inode *dir,
582 				struct ceph_mds_request *req);
583 extern void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req);
584 extern void ceph_mdsc_release_dir_caps_async(struct ceph_mds_request *req);
585 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
586 {
587 	kref_get(&req->r_kref);
588 }
589 extern void ceph_mdsc_release_request(struct kref *kref);
590 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
591 {
592 	kref_put(&req->r_kref, ceph_mdsc_release_request);
593 }
594 
595 extern void send_flush_mdlog(struct ceph_mds_session *s);
596 extern void ceph_mdsc_iterate_sessions(struct ceph_mds_client *mdsc,
597 				       void (*cb)(struct ceph_mds_session *),
598 				       bool check_state);
599 extern struct ceph_msg *ceph_create_session_msg(u32 op, u64 seq);
600 extern void __ceph_queue_cap_release(struct ceph_mds_session *session,
601 				    struct ceph_cap *cap);
602 extern void ceph_flush_session_cap_releases(struct ceph_mds_client *mdsc,
603 					    struct ceph_mds_session *session);
604 extern void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc);
605 extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
606 extern void ceph_queue_cap_unlink_work(struct ceph_mds_client *mdsc);
607 extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
608 				     int (*cb)(struct inode *, int mds, void *),
609 				     void *arg);
610 extern int ceph_mds_check_access(struct ceph_mds_client *mdsc, char *tpath,
611 				 int mask);
612 
613 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
614 
615 static inline void ceph_mdsc_free_path(char *path, int len)
616 {
617 	if (!IS_ERR_OR_NULL(path))
618 		__putname(path - (PATH_MAX - 1 - len));
619 }
620 
621 extern char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc,
622 				  struct dentry *dentry, int *plen, u64 *base,
623 				  int for_wire);
624 
625 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
626 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
627 				     struct dentry *dentry, char action,
628 				     u32 seq);
629 
630 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
631 				    struct ceph_msg *msg);
632 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
633 				   struct ceph_msg *msg);
634 
635 extern struct ceph_mds_session *
636 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
637 
638 extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
639 			  struct ceph_mds_session *session,
640 			  int max_caps);
641 
642 static inline int ceph_wait_on_async_create(struct inode *inode)
643 {
644 	struct ceph_inode_info *ci = ceph_inode(inode);
645 
646 	return wait_on_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT,
647 			   TASK_KILLABLE);
648 }
649 
650 extern int ceph_wait_on_conflict_unlink(struct dentry *dentry);
651 extern u64 ceph_get_deleg_ino(struct ceph_mds_session *session);
652 extern int ceph_restore_deleg_ino(struct ceph_mds_session *session, u64 ino);
653 
654 extern bool enable_unsafe_idmap;
655 #endif
656