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 };
45
46 /*
47 * parsed info about an mds reply, including information about
48 * either: 1) the target inode and/or its parent directory and dentry,
49 * and directory contents (for readdir results), or
50 * 2) the file range lock info (for fcntl F_GETLK results).
51 */
52 struct ceph_mds_reply_info_parsed {
53 struct ceph_mds_reply_head *head;
54
55 /* trace */
56 struct ceph_mds_reply_info_in diri, targeti;
57 struct ceph_mds_reply_dirfrag *dirfrag;
58 char *dname;
59 u32 dname_len;
60 struct ceph_mds_reply_lease *dlease;
61
62 /* extra */
63 union {
64 /* for fcntl F_GETLK results */
65 struct ceph_filelock *filelock_reply;
66
67 /* for readdir results */
68 struct {
69 struct ceph_mds_reply_dirfrag *dir_dir;
70 int dir_nr;
71 char **dir_dname;
72 u32 *dir_dname_len;
73 struct ceph_mds_reply_lease **dir_dlease;
74 struct ceph_mds_reply_info_in *dir_in;
75 u8 dir_complete, dir_end;
76 };
77 };
78
79 /* encoded blob describing snapshot contexts for certain
80 operations (e.g., open) */
81 void *snapblob;
82 int snapblob_len;
83 };
84
85
86 /*
87 * cap releases are batched and sent to the MDS en masse.
88 */
89 #define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \
90 sizeof(struct ceph_mds_cap_release)) / \
91 sizeof(struct ceph_mds_cap_item))
92
93
94 /*
95 * state associated with each MDS<->client session
96 */
97 enum {
98 CEPH_MDS_SESSION_NEW = 1,
99 CEPH_MDS_SESSION_OPENING = 2,
100 CEPH_MDS_SESSION_OPEN = 3,
101 CEPH_MDS_SESSION_HUNG = 4,
102 CEPH_MDS_SESSION_CLOSING = 5,
103 CEPH_MDS_SESSION_RESTARTING = 6,
104 CEPH_MDS_SESSION_RECONNECTING = 7,
105 };
106
107 struct ceph_mds_session {
108 struct ceph_mds_client *s_mdsc;
109 int s_mds;
110 int s_state;
111 unsigned long s_ttl; /* time until mds kills us */
112 u64 s_seq; /* incoming msg seq # */
113 struct mutex s_mutex; /* serialize session messages */
114
115 struct ceph_connection s_con;
116
117 struct ceph_auth_handshake s_auth;
118
119 /* protected by s_gen_ttl_lock */
120 spinlock_t s_gen_ttl_lock;
121 u32 s_cap_gen; /* inc each time we get mds stale msg */
122 unsigned long s_cap_ttl; /* when session caps expire */
123
124 /* protected by s_cap_lock */
125 spinlock_t s_cap_lock;
126 struct list_head s_caps; /* all caps issued by this session */
127 int s_nr_caps, s_trim_caps;
128 int s_num_cap_releases;
129 struct list_head s_cap_releases; /* waiting cap_release messages */
130 struct list_head s_cap_releases_done; /* ready to send */
131 struct ceph_cap *s_cap_iterator;
132
133 /* protected by mutex */
134 struct list_head s_cap_flushing; /* inodes w/ flushing caps */
135 struct list_head s_cap_snaps_flushing;
136 unsigned long s_renew_requested; /* last time we sent a renew req */
137 u64 s_renew_seq;
138
139 atomic_t s_ref;
140 struct list_head s_waiting; /* waiting requests */
141 struct list_head s_unsafe; /* unsafe requests */
142 };
143
144 /*
145 * modes of choosing which MDS to send a request to
146 */
147 enum {
148 USE_ANY_MDS,
149 USE_RANDOM_MDS,
150 USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
151 };
152
153 struct ceph_mds_request;
154 struct ceph_mds_client;
155
156 /*
157 * request completion callback
158 */
159 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
160 struct ceph_mds_request *req);
161
162 /*
163 * an in-flight mds request
164 */
165 struct ceph_mds_request {
166 u64 r_tid; /* transaction id */
167 struct rb_node r_node;
168 struct ceph_mds_client *r_mdsc;
169
170 int r_op; /* mds op code */
171
172 /* operation on what? */
173 struct inode *r_inode; /* arg1 */
174 struct dentry *r_dentry; /* arg1 */
175 struct dentry *r_old_dentry; /* arg2: rename from or link from */
176 struct inode *r_old_dentry_dir; /* arg2: old dentry's parent dir */
177 char *r_path1, *r_path2;
178 struct ceph_vino r_ino1, r_ino2;
179
180 struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
181 struct inode *r_target_inode; /* resulting inode */
182
183 struct mutex r_fill_mutex;
184
185 union ceph_mds_request_args r_args;
186 int r_fmode; /* file mode, if expecting cap */
187 uid_t r_uid;
188 gid_t r_gid;
189
190 /* for choosing which mds to send this request to */
191 int r_direct_mode;
192 u32 r_direct_hash; /* choose dir frag based on this dentry hash */
193 bool r_direct_is_hash; /* true if r_direct_hash is valid */
194
195 /* data payload is used for xattr ops */
196 struct page **r_pages;
197 int r_num_pages;
198 int r_data_len;
199
200 /* what caps shall we drop? */
201 int r_inode_drop, r_inode_unless;
202 int r_dentry_drop, r_dentry_unless;
203 int r_old_dentry_drop, r_old_dentry_unless;
204 struct inode *r_old_inode;
205 int r_old_inode_drop, r_old_inode_unless;
206
207 struct ceph_msg *r_request; /* original request */
208 int r_request_release_offset;
209 struct ceph_msg *r_reply;
210 struct ceph_mds_reply_info_parsed r_reply_info;
211 int r_err;
212 bool r_aborted;
213
214 unsigned long r_timeout; /* optional. jiffies */
215 unsigned long r_started; /* start time to measure timeout against */
216 unsigned long r_request_started; /* start time for mds request only,
217 used to measure lease durations */
218
219 /* link unsafe requests to parent directory, for fsync */
220 struct inode *r_unsafe_dir;
221 struct list_head r_unsafe_dir_item;
222
223 struct ceph_mds_session *r_session;
224
225 int r_attempts; /* resend attempts */
226 int r_num_fwd; /* number of forward attempts */
227 int r_resend_mds; /* mds to resend to next, if any*/
228 u32 r_sent_on_mseq; /* cap mseq request was sent at*/
229
230 struct kref r_kref;
231 struct list_head r_wait;
232 struct completion r_completion;
233 struct completion r_safe_completion;
234 ceph_mds_request_callback_t r_callback;
235 struct list_head r_unsafe_item; /* per-session unsafe list item */
236 bool r_got_unsafe, r_got_safe, r_got_result;
237
238 bool r_did_prepopulate;
239 u32 r_readdir_offset;
240
241 struct ceph_cap_reservation r_caps_reservation;
242 int r_num_caps;
243 };
244
245 /*
246 * mds client state
247 */
248 struct ceph_mds_client {
249 struct ceph_fs_client *fsc;
250 struct mutex mutex; /* all nested structures */
251
252 struct ceph_mdsmap *mdsmap;
253 struct completion safe_umount_waiters;
254 wait_queue_head_t session_close_wq;
255 struct list_head waiting_for_map;
256
257 struct ceph_mds_session **sessions; /* NULL for mds if no session */
258 int max_sessions; /* len of s_mds_sessions */
259 int stopping; /* true if shutting down */
260
261 /*
262 * snap_rwsem will cover cap linkage into snaprealms, and
263 * realm snap contexts. (later, we can do per-realm snap
264 * contexts locks..) the empty list contains realms with no
265 * references (implying they contain no inodes with caps) that
266 * should be destroyed.
267 */
268 struct rw_semaphore snap_rwsem;
269 struct rb_root snap_realms;
270 struct list_head snap_empty;
271 spinlock_t snap_empty_lock; /* protect snap_empty */
272
273 u64 last_tid; /* most recent mds request */
274 struct rb_root request_tree; /* pending mds requests */
275 struct delayed_work delayed_work; /* delayed work */
276 unsigned long last_renew_caps; /* last time we renewed our caps */
277 struct list_head cap_delay_list; /* caps with delayed release */
278 spinlock_t cap_delay_lock; /* protects cap_delay_list */
279 struct list_head snap_flush_list; /* cap_snaps ready to flush */
280 spinlock_t snap_flush_lock;
281
282 u64 cap_flush_seq;
283 struct list_head cap_dirty; /* inodes with dirty caps */
284 struct list_head cap_dirty_migrating; /* ...that are migration... */
285 int num_cap_flushing; /* # caps we are flushing */
286 spinlock_t cap_dirty_lock; /* protects above items */
287 wait_queue_head_t cap_flushing_wq;
288
289 /*
290 * Cap reservations
291 *
292 * Maintain a global pool of preallocated struct ceph_caps, referenced
293 * by struct ceph_caps_reservations. This ensures that we preallocate
294 * memory needed to successfully process an MDS response. (If an MDS
295 * sends us cap information and we fail to process it, we will have
296 * problems due to the client and MDS being out of sync.)
297 *
298 * Reservations are 'owned' by a ceph_cap_reservation context.
299 */
300 spinlock_t caps_list_lock;
301 struct list_head caps_list; /* unused (reserved or
302 unreserved) */
303 int caps_total_count; /* total caps allocated */
304 int caps_use_count; /* in use */
305 int caps_reserve_count; /* unused, reserved */
306 int caps_avail_count; /* unused, unreserved */
307 int caps_min_count; /* keep at least this many
308 (unreserved) */
309 spinlock_t dentry_lru_lock;
310 struct list_head dentry_lru;
311 int num_dentry;
312 };
313
314 extern const char *ceph_mds_op_name(int op);
315
316 extern struct ceph_mds_session *
317 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
318
319 static inline struct ceph_mds_session *
ceph_get_mds_session(struct ceph_mds_session * s)320 ceph_get_mds_session(struct ceph_mds_session *s)
321 {
322 atomic_inc(&s->s_ref);
323 return s;
324 }
325
326 extern void ceph_put_mds_session(struct ceph_mds_session *s);
327
328 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
329 struct ceph_msg *msg, int mds);
330
331 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
332 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
333 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
334
335 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
336
337 extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
338 struct inode *inode,
339 struct dentry *dn);
340
341 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
342
343 extern struct ceph_mds_request *
344 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
345 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
346 struct ceph_mds_request *req);
347 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
348 struct inode *dir,
349 struct ceph_mds_request *req);
ceph_mdsc_get_request(struct ceph_mds_request * req)350 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
351 {
352 kref_get(&req->r_kref);
353 }
354 extern void ceph_mdsc_release_request(struct kref *kref);
ceph_mdsc_put_request(struct ceph_mds_request * req)355 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
356 {
357 kref_put(&req->r_kref, ceph_mdsc_release_request);
358 }
359
360 extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
361 struct ceph_mds_session *session);
362 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
363 struct ceph_mds_session *session);
364
365 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
366
367 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
368 int stop_on_nosnap);
369
370 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
371 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
372 struct inode *inode,
373 struct dentry *dentry, char action,
374 u32 seq);
375
376 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
377 struct ceph_msg *msg);
378
379 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
380 struct ceph_mds_session *session);
381
382 #endif
383