xref: /linux/include/linux/ceph/osd_client.h (revision 021bc4b9)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _FS_CEPH_OSD_CLIENT_H
3 #define _FS_CEPH_OSD_CLIENT_H
4 
5 #include <linux/bitrev.h>
6 #include <linux/completion.h>
7 #include <linux/kref.h>
8 #include <linux/mempool.h>
9 #include <linux/rbtree.h>
10 #include <linux/refcount.h>
11 #include <linux/ktime.h>
12 
13 #include <linux/ceph/types.h>
14 #include <linux/ceph/osdmap.h>
15 #include <linux/ceph/messenger.h>
16 #include <linux/ceph/msgpool.h>
17 #include <linux/ceph/auth.h>
18 #include <linux/ceph/pagelist.h>
19 
20 struct ceph_msg;
21 struct ceph_snap_context;
22 struct ceph_osd_request;
23 struct ceph_osd_client;
24 
25 /*
26  * completion callback for async writepages
27  */
28 typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *);
29 
30 #define CEPH_HOMELESS_OSD	-1
31 
32 /*
33  * A single extent in a SPARSE_READ reply.
34  *
35  * Note that these come from the OSD as little-endian values. On BE arches,
36  * we convert them in-place after receipt.
37  */
38 struct ceph_sparse_extent {
39 	u64	off;
40 	u64	len;
41 } __packed;
42 
43 /* Sparse read state machine state values */
44 enum ceph_sparse_read_state {
45 	CEPH_SPARSE_READ_HDR	= 0,
46 	CEPH_SPARSE_READ_EXTENTS,
47 	CEPH_SPARSE_READ_DATA_LEN,
48 	CEPH_SPARSE_READ_DATA_PRE,
49 	CEPH_SPARSE_READ_DATA,
50 };
51 
52 /*
53  * A SPARSE_READ reply is a 32-bit count of extents, followed by an array of
54  * 64-bit offset/length pairs, and then all of the actual file data
55  * concatenated after it (sans holes).
56  *
57  * Unfortunately, we don't know how long the extent array is until we've
58  * started reading the data section of the reply. The caller should send down
59  * a destination buffer for the array, but we'll alloc one if it's too small
60  * or if the caller doesn't.
61  */
62 struct ceph_sparse_read {
63 	enum ceph_sparse_read_state	sr_state;    /* state machine state */
64 	u64				sr_req_off;  /* orig request offset */
65 	u64				sr_req_len;  /* orig request length */
66 	u64				sr_pos;      /* current pos in buffer */
67 	int				sr_index;    /* current extent index */
68 	u32				sr_datalen;  /* length of actual data */
69 	u32				sr_count;    /* extent count in reply */
70 	int				sr_ext_len;  /* length of extent array */
71 	struct ceph_sparse_extent	*sr_extent;  /* extent array */
72 };
73 
74 /*
75  * A given osd we're communicating with.
76  *
77  * Note that the o_requests tree can be searched while holding the "lock" mutex
78  * or the "o_requests_lock" spinlock. Insertion or removal requires both!
79  */
80 struct ceph_osd {
81 	refcount_t o_ref;
82 	int o_sparse_op_idx;
83 	struct ceph_osd_client *o_osdc;
84 	int o_osd;
85 	int o_incarnation;
86 	struct rb_node o_node;
87 	struct ceph_connection o_con;
88 	spinlock_t o_requests_lock;
89 	struct rb_root o_requests;
90 	struct rb_root o_linger_requests;
91 	struct rb_root o_backoff_mappings;
92 	struct rb_root o_backoffs_by_id;
93 	struct list_head o_osd_lru;
94 	struct ceph_auth_handshake o_auth;
95 	unsigned long lru_ttl;
96 	struct list_head o_keepalive_item;
97 	struct mutex lock;
98 	struct ceph_sparse_read	o_sparse_read;
99 };
100 
101 #define CEPH_OSD_SLAB_OPS	2
102 #define CEPH_OSD_MAX_OPS	16
103 
104 enum ceph_osd_data_type {
105 	CEPH_OSD_DATA_TYPE_NONE = 0,
106 	CEPH_OSD_DATA_TYPE_PAGES,
107 	CEPH_OSD_DATA_TYPE_PAGELIST,
108 #ifdef CONFIG_BLOCK
109 	CEPH_OSD_DATA_TYPE_BIO,
110 #endif /* CONFIG_BLOCK */
111 	CEPH_OSD_DATA_TYPE_BVECS,
112 	CEPH_OSD_DATA_TYPE_ITER,
113 };
114 
115 struct ceph_osd_data {
116 	enum ceph_osd_data_type	type;
117 	union {
118 		struct {
119 			struct page	**pages;
120 			u64		length;
121 			u32		alignment;
122 			bool		pages_from_pool;
123 			bool		own_pages;
124 		};
125 		struct ceph_pagelist	*pagelist;
126 #ifdef CONFIG_BLOCK
127 		struct {
128 			struct ceph_bio_iter	bio_pos;
129 			u32			bio_length;
130 		};
131 #endif /* CONFIG_BLOCK */
132 		struct {
133 			struct ceph_bvec_iter	bvec_pos;
134 			u32			num_bvecs;
135 		};
136 		struct iov_iter		iter;
137 	};
138 };
139 
140 struct ceph_osd_req_op {
141 	u16 op;           /* CEPH_OSD_OP_* */
142 	u32 flags;        /* CEPH_OSD_OP_FLAG_* */
143 	u32 indata_len;   /* request */
144 	u32 outdata_len;  /* reply */
145 	s32 rval;
146 
147 	union {
148 		struct ceph_osd_data raw_data_in;
149 		struct {
150 			u64 offset, length;
151 			u64 truncate_size;
152 			u32 truncate_seq;
153 			int sparse_ext_cnt;
154 			struct ceph_sparse_extent *sparse_ext;
155 			struct ceph_osd_data osd_data;
156 		} extent;
157 		struct {
158 			u32 name_len;
159 			u32 value_len;
160 			__u8 cmp_op;       /* CEPH_OSD_CMPXATTR_OP_* */
161 			__u8 cmp_mode;     /* CEPH_OSD_CMPXATTR_MODE_* */
162 			struct ceph_osd_data osd_data;
163 		} xattr;
164 		struct {
165 			const char *class_name;
166 			const char *method_name;
167 			struct ceph_osd_data request_info;
168 			struct ceph_osd_data request_data;
169 			struct ceph_osd_data response_data;
170 			__u8 class_len;
171 			__u8 method_len;
172 			u32 indata_len;
173 		} cls;
174 		struct {
175 			u64 cookie;
176 			__u8 op;           /* CEPH_OSD_WATCH_OP_ */
177 			u32 gen;
178 		} watch;
179 		struct {
180 			struct ceph_osd_data request_data;
181 		} notify_ack;
182 		struct {
183 			u64 cookie;
184 			struct ceph_osd_data request_data;
185 			struct ceph_osd_data response_data;
186 		} notify;
187 		struct {
188 			struct ceph_osd_data response_data;
189 		} list_watchers;
190 		struct {
191 			u64 expected_object_size;
192 			u64 expected_write_size;
193 			u32 flags;  /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
194 		} alloc_hint;
195 		struct {
196 			u64 snapid;
197 			u64 src_version;
198 			u8 flags;
199 			u32 src_fadvise_flags;
200 			struct ceph_osd_data osd_data;
201 		} copy_from;
202 		struct {
203 			u64 ver;
204 		} assert_ver;
205 	};
206 };
207 
208 struct ceph_osd_request_target {
209 	struct ceph_object_id base_oid;
210 	struct ceph_object_locator base_oloc;
211 	struct ceph_object_id target_oid;
212 	struct ceph_object_locator target_oloc;
213 
214 	struct ceph_pg pgid;               /* last raw pg we mapped to */
215 	struct ceph_spg spgid;             /* last actual spg we mapped to */
216 	u32 pg_num;
217 	u32 pg_num_mask;
218 	struct ceph_osds acting;
219 	struct ceph_osds up;
220 	int size;
221 	int min_size;
222 	bool sort_bitwise;
223 	bool recovery_deletes;
224 
225 	unsigned int flags;                /* CEPH_OSD_FLAG_* */
226 	bool used_replica;
227 	bool paused;
228 
229 	u32 epoch;
230 	u32 last_force_resend;
231 
232 	int osd;
233 };
234 
235 /* an in-flight request */
236 struct ceph_osd_request {
237 	u64             r_tid;              /* unique for this client */
238 	struct rb_node  r_node;
239 	struct rb_node  r_mc_node;          /* map check */
240 	struct work_struct r_complete_work;
241 	struct ceph_osd *r_osd;
242 
243 	struct ceph_osd_request_target r_t;
244 #define r_base_oid	r_t.base_oid
245 #define r_base_oloc	r_t.base_oloc
246 #define r_flags		r_t.flags
247 
248 	struct ceph_msg  *r_request, *r_reply;
249 	u32               r_sent;      /* >0 if r_request is sending/sent */
250 
251 	/* request osd ops array  */
252 	unsigned int		r_num_ops;
253 
254 	int               r_result;
255 
256 	struct ceph_osd_client *r_osdc;
257 	struct kref       r_kref;
258 	bool              r_mempool;
259 	bool		  r_linger;           /* don't resend on failure */
260 	struct completion r_completion;       /* private to osd_client.c */
261 	ceph_osdc_callback_t r_callback;
262 
263 	struct inode *r_inode;         	      /* for use by callbacks */
264 	struct list_head r_private_item;      /* ditto */
265 	void *r_priv;			      /* ditto */
266 
267 	/* set by submitter */
268 	u64 r_snapid;                         /* for reads, CEPH_NOSNAP o/w */
269 	struct ceph_snap_context *r_snapc;    /* for writes */
270 	struct timespec64 r_mtime;            /* ditto */
271 	u64 r_data_offset;                    /* ditto */
272 
273 	/* internal */
274 	u64 r_version;			      /* data version sent in reply */
275 	unsigned long r_stamp;                /* jiffies, send or check time */
276 	unsigned long r_start_stamp;          /* jiffies */
277 	ktime_t r_start_latency;              /* ktime_t */
278 	ktime_t r_end_latency;                /* ktime_t */
279 	int r_attempts;
280 	u32 r_map_dne_bound;
281 
282 	struct ceph_osd_req_op r_ops[] __counted_by(r_num_ops);
283 };
284 
285 struct ceph_request_redirect {
286 	struct ceph_object_locator oloc;
287 };
288 
289 /*
290  * osd request identifier
291  *
292  * caller name + incarnation# + tid to unique identify this request
293  */
294 struct ceph_osd_reqid {
295 	struct ceph_entity_name name;
296 	__le64 tid;
297 	__le32 inc;
298 } __packed;
299 
300 struct ceph_blkin_trace_info {
301 	__le64 trace_id;
302 	__le64 span_id;
303 	__le64 parent_span_id;
304 } __packed;
305 
306 typedef void (*rados_watchcb2_t)(void *arg, u64 notify_id, u64 cookie,
307 				 u64 notifier_id, void *data, size_t data_len);
308 typedef void (*rados_watcherrcb_t)(void *arg, u64 cookie, int err);
309 
310 struct ceph_osd_linger_request {
311 	struct ceph_osd_client *osdc;
312 	u64 linger_id;
313 	bool committed;
314 	bool is_watch;                  /* watch or notify */
315 
316 	struct ceph_osd *osd;
317 	struct ceph_osd_request *reg_req;
318 	struct ceph_osd_request *ping_req;
319 	unsigned long ping_sent;
320 	unsigned long watch_valid_thru;
321 	struct list_head pending_lworks;
322 
323 	struct ceph_osd_request_target t;
324 	u32 map_dne_bound;
325 
326 	struct timespec64 mtime;
327 
328 	struct kref kref;
329 	struct mutex lock;
330 	struct rb_node node;            /* osd */
331 	struct rb_node osdc_node;       /* osdc */
332 	struct rb_node mc_node;         /* map check */
333 	struct list_head scan_item;
334 
335 	struct completion reg_commit_wait;
336 	struct completion notify_finish_wait;
337 	int reg_commit_error;
338 	int notify_finish_error;
339 	int last_error;
340 
341 	u32 register_gen;
342 	u64 notify_id;
343 
344 	rados_watchcb2_t wcb;
345 	rados_watcherrcb_t errcb;
346 	void *data;
347 
348 	struct ceph_pagelist *request_pl;
349 	struct page **notify_id_pages;
350 
351 	struct page ***preply_pages;
352 	size_t *preply_len;
353 };
354 
355 struct ceph_watch_item {
356 	struct ceph_entity_name name;
357 	u64 cookie;
358 	struct ceph_entity_addr addr;
359 };
360 
361 struct ceph_spg_mapping {
362 	struct rb_node node;
363 	struct ceph_spg spgid;
364 
365 	struct rb_root backoffs;
366 };
367 
368 struct ceph_hobject_id {
369 	void *key;
370 	size_t key_len;
371 	void *oid;
372 	size_t oid_len;
373 	u64 snapid;
374 	u32 hash;
375 	u8 is_max;
376 	void *nspace;
377 	size_t nspace_len;
378 	s64 pool;
379 
380 	/* cache */
381 	u32 hash_reverse_bits;
382 };
383 
384 static inline void ceph_hoid_build_hash_cache(struct ceph_hobject_id *hoid)
385 {
386 	hoid->hash_reverse_bits = bitrev32(hoid->hash);
387 }
388 
389 /*
390  * PG-wide backoff: [begin, end)
391  * per-object backoff: begin == end
392  */
393 struct ceph_osd_backoff {
394 	struct rb_node spg_node;
395 	struct rb_node id_node;
396 
397 	struct ceph_spg spgid;
398 	u64 id;
399 	struct ceph_hobject_id *begin;
400 	struct ceph_hobject_id *end;
401 };
402 
403 #define CEPH_LINGER_ID_START	0xffff000000000000ULL
404 
405 struct ceph_osd_client {
406 	struct ceph_client     *client;
407 
408 	struct ceph_osdmap     *osdmap;       /* current map */
409 	struct rw_semaphore    lock;
410 
411 	struct rb_root         osds;          /* osds */
412 	struct list_head       osd_lru;       /* idle osds */
413 	spinlock_t             osd_lru_lock;
414 	u32		       epoch_barrier;
415 	struct ceph_osd        homeless_osd;
416 	atomic64_t             last_tid;      /* tid of last request */
417 	u64                    last_linger_id;
418 	struct rb_root         linger_requests; /* lingering requests */
419 	struct rb_root         map_checks;
420 	struct rb_root         linger_map_checks;
421 	atomic_t               num_requests;
422 	atomic_t               num_homeless;
423 	int                    abort_err;
424 	struct delayed_work    timeout_work;
425 	struct delayed_work    osds_timeout_work;
426 #ifdef CONFIG_DEBUG_FS
427 	struct dentry 	       *debugfs_file;
428 #endif
429 
430 	mempool_t              *req_mempool;
431 
432 	struct ceph_msgpool	msgpool_op;
433 	struct ceph_msgpool	msgpool_op_reply;
434 
435 	struct workqueue_struct	*notify_wq;
436 	struct workqueue_struct	*completion_wq;
437 };
438 
439 static inline bool ceph_osdmap_flag(struct ceph_osd_client *osdc, int flag)
440 {
441 	return osdc->osdmap->flags & flag;
442 }
443 
444 extern int ceph_osdc_setup(void);
445 extern void ceph_osdc_cleanup(void);
446 
447 extern int ceph_osdc_init(struct ceph_osd_client *osdc,
448 			  struct ceph_client *client);
449 extern void ceph_osdc_stop(struct ceph_osd_client *osdc);
450 extern void ceph_osdc_reopen_osds(struct ceph_osd_client *osdc);
451 
452 extern void ceph_osdc_handle_reply(struct ceph_osd_client *osdc,
453 				   struct ceph_msg *msg);
454 extern void ceph_osdc_handle_map(struct ceph_osd_client *osdc,
455 				 struct ceph_msg *msg);
456 void ceph_osdc_update_epoch_barrier(struct ceph_osd_client *osdc, u32 eb);
457 void ceph_osdc_abort_requests(struct ceph_osd_client *osdc, int err);
458 void ceph_osdc_clear_abort_err(struct ceph_osd_client *osdc);
459 
460 #define osd_req_op_data(oreq, whch, typ, fld)				\
461 ({									\
462 	struct ceph_osd_request *__oreq = (oreq);			\
463 	unsigned int __whch = (whch);					\
464 	BUG_ON(__whch >= __oreq->r_num_ops);				\
465 	&__oreq->r_ops[__whch].typ.fld;					\
466 })
467 
468 struct ceph_osd_req_op *osd_req_op_init(struct ceph_osd_request *osd_req,
469 			    unsigned int which, u16 opcode, u32 flags);
470 
471 extern void osd_req_op_raw_data_in_pages(struct ceph_osd_request *,
472 					unsigned int which,
473 					struct page **pages, u64 length,
474 					u32 alignment, bool pages_from_pool,
475 					bool own_pages);
476 
477 extern void osd_req_op_extent_init(struct ceph_osd_request *osd_req,
478 					unsigned int which, u16 opcode,
479 					u64 offset, u64 length,
480 					u64 truncate_size, u32 truncate_seq);
481 extern void osd_req_op_extent_update(struct ceph_osd_request *osd_req,
482 					unsigned int which, u64 length);
483 extern void osd_req_op_extent_dup_last(struct ceph_osd_request *osd_req,
484 				       unsigned int which, u64 offset_inc);
485 
486 extern struct ceph_osd_data *osd_req_op_extent_osd_data(
487 					struct ceph_osd_request *osd_req,
488 					unsigned int which);
489 
490 extern void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *,
491 					unsigned int which,
492 					struct page **pages, u64 length,
493 					u32 alignment, bool pages_from_pool,
494 					bool own_pages);
495 extern void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *,
496 					unsigned int which,
497 					struct ceph_pagelist *pagelist);
498 #ifdef CONFIG_BLOCK
499 void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
500 				    unsigned int which,
501 				    struct ceph_bio_iter *bio_pos,
502 				    u32 bio_length);
503 #endif /* CONFIG_BLOCK */
504 void osd_req_op_extent_osd_data_bvecs(struct ceph_osd_request *osd_req,
505 				      unsigned int which,
506 				      struct bio_vec *bvecs, u32 num_bvecs,
507 				      u32 bytes);
508 void osd_req_op_extent_osd_data_bvec_pos(struct ceph_osd_request *osd_req,
509 					 unsigned int which,
510 					 struct ceph_bvec_iter *bvec_pos);
511 void osd_req_op_extent_osd_iter(struct ceph_osd_request *osd_req,
512 				unsigned int which, struct iov_iter *iter);
513 
514 extern void osd_req_op_cls_request_data_pagelist(struct ceph_osd_request *,
515 					unsigned int which,
516 					struct ceph_pagelist *pagelist);
517 extern void osd_req_op_cls_request_data_pages(struct ceph_osd_request *,
518 					unsigned int which,
519 					struct page **pages, u64 length,
520 					u32 alignment, bool pages_from_pool,
521 					bool own_pages);
522 void osd_req_op_cls_request_data_bvecs(struct ceph_osd_request *osd_req,
523 				       unsigned int which,
524 				       struct bio_vec *bvecs, u32 num_bvecs,
525 				       u32 bytes);
526 extern void osd_req_op_cls_response_data_pages(struct ceph_osd_request *,
527 					unsigned int which,
528 					struct page **pages, u64 length,
529 					u32 alignment, bool pages_from_pool,
530 					bool own_pages);
531 int osd_req_op_cls_init(struct ceph_osd_request *osd_req, unsigned int which,
532 			const char *class, const char *method);
533 extern int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int which,
534 				 u16 opcode, const char *name, const void *value,
535 				 size_t size, u8 cmp_op, u8 cmp_mode);
536 extern void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
537 				       unsigned int which,
538 				       u64 expected_object_size,
539 				       u64 expected_write_size,
540 				       u32 flags);
541 extern int osd_req_op_copy_from_init(struct ceph_osd_request *req,
542 				     u64 src_snapid, u64 src_version,
543 				     struct ceph_object_id *src_oid,
544 				     struct ceph_object_locator *src_oloc,
545 				     u32 src_fadvise_flags,
546 				     u32 dst_fadvise_flags,
547 				     u32 truncate_seq, u64 truncate_size,
548 				     u8 copy_from_flags);
549 
550 extern struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
551 					       struct ceph_snap_context *snapc,
552 					       unsigned int num_ops,
553 					       bool use_mempool,
554 					       gfp_t gfp_flags);
555 int ceph_osdc_alloc_messages(struct ceph_osd_request *req, gfp_t gfp);
556 
557 extern struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *,
558 				      struct ceph_file_layout *layout,
559 				      struct ceph_vino vino,
560 				      u64 offset, u64 *len,
561 				      unsigned int which, int num_ops,
562 				      int opcode, int flags,
563 				      struct ceph_snap_context *snapc,
564 				      u32 truncate_seq, u64 truncate_size,
565 				      bool use_mempool);
566 
567 int __ceph_alloc_sparse_ext_map(struct ceph_osd_req_op *op, int cnt);
568 
569 /*
570  * How big an extent array should we preallocate for a sparse read? This is
571  * just a starting value.  If we get more than this back from the OSD, the
572  * receiver will reallocate.
573  */
574 #define CEPH_SPARSE_EXT_ARRAY_INITIAL  16
575 
576 static inline int ceph_alloc_sparse_ext_map(struct ceph_osd_req_op *op, int cnt)
577 {
578 	if (!cnt)
579 		cnt = CEPH_SPARSE_EXT_ARRAY_INITIAL;
580 
581 	return __ceph_alloc_sparse_ext_map(op, cnt);
582 }
583 
584 extern void ceph_osdc_get_request(struct ceph_osd_request *req);
585 extern void ceph_osdc_put_request(struct ceph_osd_request *req);
586 
587 void ceph_osdc_start_request(struct ceph_osd_client *osdc,
588 			     struct ceph_osd_request *req);
589 extern void ceph_osdc_cancel_request(struct ceph_osd_request *req);
590 extern int ceph_osdc_wait_request(struct ceph_osd_client *osdc,
591 				  struct ceph_osd_request *req);
592 extern void ceph_osdc_sync(struct ceph_osd_client *osdc);
593 
594 extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc);
595 void ceph_osdc_maybe_request_map(struct ceph_osd_client *osdc);
596 
597 int ceph_osdc_call(struct ceph_osd_client *osdc,
598 		   struct ceph_object_id *oid,
599 		   struct ceph_object_locator *oloc,
600 		   const char *class, const char *method,
601 		   unsigned int flags,
602 		   struct page *req_page, size_t req_len,
603 		   struct page **resp_pages, size_t *resp_len);
604 
605 /* watch/notify */
606 struct ceph_osd_linger_request *
607 ceph_osdc_watch(struct ceph_osd_client *osdc,
608 		struct ceph_object_id *oid,
609 		struct ceph_object_locator *oloc,
610 		rados_watchcb2_t wcb,
611 		rados_watcherrcb_t errcb,
612 		void *data);
613 int ceph_osdc_unwatch(struct ceph_osd_client *osdc,
614 		      struct ceph_osd_linger_request *lreq);
615 
616 int ceph_osdc_notify_ack(struct ceph_osd_client *osdc,
617 			 struct ceph_object_id *oid,
618 			 struct ceph_object_locator *oloc,
619 			 u64 notify_id,
620 			 u64 cookie,
621 			 void *payload,
622 			 u32 payload_len);
623 int ceph_osdc_notify(struct ceph_osd_client *osdc,
624 		     struct ceph_object_id *oid,
625 		     struct ceph_object_locator *oloc,
626 		     void *payload,
627 		     u32 payload_len,
628 		     u32 timeout,
629 		     struct page ***preply_pages,
630 		     size_t *preply_len);
631 int ceph_osdc_watch_check(struct ceph_osd_client *osdc,
632 			  struct ceph_osd_linger_request *lreq);
633 int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
634 			    struct ceph_object_id *oid,
635 			    struct ceph_object_locator *oloc,
636 			    struct ceph_watch_item **watchers,
637 			    u32 *num_watchers);
638 
639 /* Find offset into the buffer of the end of the extent map */
640 static inline u64 ceph_sparse_ext_map_end(struct ceph_osd_req_op *op)
641 {
642 	struct ceph_sparse_extent *ext;
643 
644 	/* No extents? No data */
645 	if (op->extent.sparse_ext_cnt == 0)
646 		return 0;
647 
648 	ext = &op->extent.sparse_ext[op->extent.sparse_ext_cnt - 1];
649 
650 	return ext->off + ext->len - op->extent.offset;
651 }
652 
653 #endif
654