1 #ifndef _FS_CEPH_MDS_CLIENT_H
2 #define _FS_CEPH_MDS_CLIENT_H
3
4 #include <linux/completion.h>
5 #include <linux/kref.h>
6 #include <linux/list.h>
7 #include <linux/mutex.h>
8 #include <linux/rbtree.h>
9 #include <linux/spinlock.h>
10
11 #include <linux/ceph/types.h>
12 #include <linux/ceph/messenger.h>
13 #include <linux/ceph/mdsmap.h>
14 #include <linux/ceph/auth.h>
15
16 /*
17 * Some lock dependencies:
18 *
19 * session->s_mutex
20 * mdsc->mutex
21 *
22 * mdsc->snap_rwsem
23 *
24 * ci->i_ceph_lock
25 * mdsc->snap_flush_lock
26 * mdsc->cap_delay_lock
27 *
28 */
29
30 struct ceph_fs_client;
31 struct ceph_cap;
32
33 /*
34 * parsed info about a single inode. pointers are into the encoded
35 * on-wire structures within the mds reply message payload.
36 */
37 struct ceph_mds_reply_info_in {
38 struct ceph_mds_reply_inode *in;
39 struct ceph_dir_layout dir_layout;
40 u32 symlink_len;
41 char *symlink;
42 u32 xattr_len;
43 char *xattr_data;
44 u64 inline_version;
45 u32 inline_len;
46 char *inline_data;
47 u32 pool_ns_len;
48 char *pool_ns_data;
49 };
50
51 struct ceph_mds_reply_dir_entry {
52 char *name;
53 u32 name_len;
54 struct ceph_mds_reply_lease *lease;
55 struct ceph_mds_reply_info_in inode;
56 loff_t offset;
57 };
58
59 /*
60 * parsed info about an mds reply, including information about
61 * either: 1) the target inode and/or its parent directory and dentry,
62 * and directory contents (for readdir results), or
63 * 2) the file range lock info (for fcntl F_GETLK results).
64 */
65 struct ceph_mds_reply_info_parsed {
66 struct ceph_mds_reply_head *head;
67
68 /* trace */
69 struct ceph_mds_reply_info_in diri, targeti;
70 struct ceph_mds_reply_dirfrag *dirfrag;
71 char *dname;
72 u32 dname_len;
73 struct ceph_mds_reply_lease *dlease;
74
75 /* extra */
76 union {
77 /* for fcntl F_GETLK results */
78 struct ceph_filelock *filelock_reply;
79
80 /* for readdir results */
81 struct {
82 struct ceph_mds_reply_dirfrag *dir_dir;
83 size_t dir_buf_size;
84 int dir_nr;
85 bool dir_complete;
86 bool dir_end;
87 bool hash_order;
88 struct ceph_mds_reply_dir_entry *dir_entries;
89 };
90
91 /* for create results */
92 struct {
93 bool has_create_ino;
94 u64 ino;
95 };
96 };
97
98 /* encoded blob describing snapshot contexts for certain
99 operations (e.g., open) */
100 void *snapblob;
101 int snapblob_len;
102 };
103
104
105 /*
106 * cap releases are batched and sent to the MDS en masse.
107 */
108 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - \
109 sizeof(struct ceph_mds_cap_release)) / \
110 sizeof(struct ceph_mds_cap_item))
111
112
113 /*
114 * state associated with each MDS<->client session
115 */
116 enum {
117 CEPH_MDS_SESSION_NEW = 1,
118 CEPH_MDS_SESSION_OPENING = 2,
119 CEPH_MDS_SESSION_OPEN = 3,
120 CEPH_MDS_SESSION_HUNG = 4,
121 CEPH_MDS_SESSION_CLOSING = 5,
122 CEPH_MDS_SESSION_RESTARTING = 6,
123 CEPH_MDS_SESSION_RECONNECTING = 7,
124 CEPH_MDS_SESSION_REJECTED = 8,
125 };
126
127 struct ceph_mds_session {
128 struct ceph_mds_client *s_mdsc;
129 int s_mds;
130 int s_state;
131 unsigned long s_ttl; /* time until mds kills us */
132 u64 s_seq; /* incoming msg seq # */
133 struct mutex s_mutex; /* serialize session messages */
134
135 struct ceph_connection s_con;
136
137 struct ceph_auth_handshake s_auth;
138
139 /* protected by s_gen_ttl_lock */
140 spinlock_t s_gen_ttl_lock;
141 u32 s_cap_gen; /* inc each time we get mds stale msg */
142 unsigned long s_cap_ttl; /* when session caps expire */
143
144 /* protected by s_cap_lock */
145 spinlock_t s_cap_lock;
146 struct list_head s_caps; /* all caps issued by this session */
147 int s_nr_caps, s_trim_caps;
148 int s_num_cap_releases;
149 int s_cap_reconnect;
150 int s_readonly;
151 struct list_head s_cap_releases; /* waiting cap_release messages */
152 struct ceph_cap *s_cap_iterator;
153
154 /* protected by mutex */
155 struct list_head s_cap_flushing; /* inodes w/ flushing caps */
156 unsigned long s_renew_requested; /* last time we sent a renew req */
157 u64 s_renew_seq;
158
159 atomic_t s_ref;
160 struct list_head s_waiting; /* waiting requests */
161 struct list_head s_unsafe; /* unsafe requests */
162 };
163
164 /*
165 * modes of choosing which MDS to send a request to
166 */
167 enum {
168 USE_ANY_MDS,
169 USE_RANDOM_MDS,
170 USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
171 };
172
173 struct ceph_mds_request;
174 struct ceph_mds_client;
175
176 /*
177 * request completion callback
178 */
179 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
180 struct ceph_mds_request *req);
181 /*
182 * wait for request completion callback
183 */
184 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
185 struct ceph_mds_request *req);
186
187 /*
188 * an in-flight mds request
189 */
190 struct ceph_mds_request {
191 u64 r_tid; /* transaction id */
192 struct rb_node r_node;
193 struct ceph_mds_client *r_mdsc;
194
195 int r_op; /* mds op code */
196
197 /* operation on what? */
198 struct inode *r_inode; /* arg1 */
199 struct dentry *r_dentry; /* arg1 */
200 struct dentry *r_old_dentry; /* arg2: rename from or link from */
201 struct inode *r_old_dentry_dir; /* arg2: old dentry's parent dir */
202 char *r_path1, *r_path2;
203 struct ceph_vino r_ino1, r_ino2;
204
205 struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
206 struct inode *r_target_inode; /* resulting inode */
207
208 struct mutex r_fill_mutex;
209
210 union ceph_mds_request_args r_args;
211 int r_fmode; /* file mode, if expecting cap */
212 kuid_t r_uid;
213 kgid_t r_gid;
214 struct timespec r_stamp;
215
216 /* for choosing which mds to send this request to */
217 int r_direct_mode;
218 u32 r_direct_hash; /* choose dir frag based on this dentry hash */
219 bool r_direct_is_hash; /* true if r_direct_hash is valid */
220
221 /* data payload is used for xattr ops */
222 struct ceph_pagelist *r_pagelist;
223
224 /* what caps shall we drop? */
225 int r_inode_drop, r_inode_unless;
226 int r_dentry_drop, r_dentry_unless;
227 int r_old_dentry_drop, r_old_dentry_unless;
228 struct inode *r_old_inode;
229 int r_old_inode_drop, r_old_inode_unless;
230
231 struct ceph_msg *r_request; /* original request */
232 int r_request_release_offset;
233 struct ceph_msg *r_reply;
234 struct ceph_mds_reply_info_parsed r_reply_info;
235 struct page *r_locked_page;
236 int r_err;
237 bool r_aborted;
238
239 unsigned long r_timeout; /* optional. jiffies, 0 is "wait forever" */
240 unsigned long r_started; /* start time to measure timeout against */
241 unsigned long r_request_started; /* start time for mds request only,
242 used to measure lease durations */
243
244 /* link unsafe requests to parent directory, for fsync */
245 struct inode *r_unsafe_dir;
246 struct list_head r_unsafe_dir_item;
247
248 /* unsafe requests that modify the target inode */
249 struct list_head r_unsafe_target_item;
250
251 struct ceph_mds_session *r_session;
252
253 int r_attempts; /* resend attempts */
254 int r_num_fwd; /* number of forward attempts */
255 int r_resend_mds; /* mds to resend to next, if any*/
256 u32 r_sent_on_mseq; /* cap mseq request was sent at*/
257
258 struct kref r_kref;
259 struct list_head r_wait;
260 struct completion r_completion;
261 struct completion r_safe_completion;
262 ceph_mds_request_callback_t r_callback;
263 ceph_mds_request_wait_callback_t r_wait_for_completion;
264 struct list_head r_unsafe_item; /* per-session unsafe list item */
265 bool r_got_unsafe, r_got_safe, r_got_result;
266
267 bool r_did_prepopulate;
268 long long r_dir_release_cnt;
269 long long r_dir_ordered_cnt;
270 int r_readdir_cache_idx;
271 u32 r_readdir_offset;
272
273 struct ceph_cap_reservation r_caps_reservation;
274 int r_num_caps;
275 };
276
277 struct ceph_pool_perm {
278 struct rb_node node;
279 int perm;
280 s64 pool;
281 size_t pool_ns_len;
282 char pool_ns[];
283 };
284
285 /*
286 * mds client state
287 */
288 struct ceph_mds_client {
289 struct ceph_fs_client *fsc;
290 struct mutex mutex; /* all nested structures */
291
292 struct ceph_mdsmap *mdsmap;
293 struct completion safe_umount_waiters;
294 wait_queue_head_t session_close_wq;
295 struct list_head waiting_for_map;
296 int mdsmap_err;
297
298 struct ceph_mds_session **sessions; /* NULL for mds if no session */
299 atomic_t num_sessions;
300 int max_sessions; /* len of s_mds_sessions */
301 int stopping; /* true if shutting down */
302
303 /*
304 * snap_rwsem will cover cap linkage into snaprealms, and
305 * realm snap contexts. (later, we can do per-realm snap
306 * contexts locks..) the empty list contains realms with no
307 * references (implying they contain no inodes with caps) that
308 * should be destroyed.
309 */
310 u64 last_snap_seq;
311 struct rw_semaphore snap_rwsem;
312 struct rb_root snap_realms;
313 struct list_head snap_empty;
314 spinlock_t snap_empty_lock; /* protect snap_empty */
315
316 u64 last_tid; /* most recent mds request */
317 u64 oldest_tid; /* oldest incomplete mds request,
318 excluding setfilelock requests */
319 struct rb_root request_tree; /* pending mds requests */
320 struct delayed_work delayed_work; /* delayed work */
321 unsigned long last_renew_caps; /* last time we renewed our caps */
322 struct list_head cap_delay_list; /* caps with delayed release */
323 spinlock_t cap_delay_lock; /* protects cap_delay_list */
324 struct list_head snap_flush_list; /* cap_snaps ready to flush */
325 spinlock_t snap_flush_lock;
326
327 u64 last_cap_flush_tid;
328 struct list_head cap_flush_list;
329 struct list_head cap_dirty; /* inodes with dirty caps */
330 struct list_head cap_dirty_migrating; /* ...that are migration... */
331 int num_cap_flushing; /* # caps we are flushing */
332 spinlock_t cap_dirty_lock; /* protects above items */
333 wait_queue_head_t cap_flushing_wq;
334
335 /*
336 * Cap reservations
337 *
338 * Maintain a global pool of preallocated struct ceph_caps, referenced
339 * by struct ceph_caps_reservations. This ensures that we preallocate
340 * memory needed to successfully process an MDS response. (If an MDS
341 * sends us cap information and we fail to process it, we will have
342 * problems due to the client and MDS being out of sync.)
343 *
344 * Reservations are 'owned' by a ceph_cap_reservation context.
345 */
346 spinlock_t caps_list_lock;
347 struct list_head caps_list; /* unused (reserved or
348 unreserved) */
349 int caps_total_count; /* total caps allocated */
350 int caps_use_count; /* in use */
351 int caps_reserve_count; /* unused, reserved */
352 int caps_avail_count; /* unused, unreserved */
353 int caps_min_count; /* keep at least this many
354 (unreserved) */
355 spinlock_t dentry_lru_lock;
356 struct list_head dentry_lru;
357 int num_dentry;
358
359 struct rw_semaphore pool_perm_rwsem;
360 struct rb_root pool_perm_tree;
361 };
362
363 extern const char *ceph_mds_op_name(int op);
364
365 extern struct ceph_mds_session *
366 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
367
368 static inline struct ceph_mds_session *
ceph_get_mds_session(struct ceph_mds_session * s)369 ceph_get_mds_session(struct ceph_mds_session *s)
370 {
371 atomic_inc(&s->s_ref);
372 return s;
373 }
374
375 extern const char *ceph_session_state_name(int s);
376
377 extern void ceph_put_mds_session(struct ceph_mds_session *s);
378
379 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
380 struct ceph_msg *msg, int mds);
381
382 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
383 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
384 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
385 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
386
387 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
388
389 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
390 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
391 struct inode *dir);
392 extern struct ceph_mds_request *
393 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
394 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
395 struct ceph_mds_request *req);
396 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
397 struct inode *dir,
398 struct ceph_mds_request *req);
ceph_mdsc_get_request(struct ceph_mds_request * req)399 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
400 {
401 kref_get(&req->r_kref);
402 }
403 extern void ceph_mdsc_release_request(struct kref *kref);
ceph_mdsc_put_request(struct ceph_mds_request * req)404 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
405 {
406 kref_put(&req->r_kref, ceph_mdsc_release_request);
407 }
408
409 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
410 struct ceph_mds_session *session);
411
412 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
413
414 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
415 int stop_on_nosnap);
416
417 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
418 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
419 struct inode *inode,
420 struct dentry *dentry, char action,
421 u32 seq);
422
423 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
424 struct ceph_msg *msg);
425 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
426 struct ceph_msg *msg);
427
428 extern struct ceph_mds_session *
429 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
430 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
431 struct ceph_mds_session *session);
432
433 #endif
434