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 };
48
49 /*
50 * parsed info about an mds reply, including information about
51 * either: 1) the target inode and/or its parent directory and dentry,
52 * and directory contents (for readdir results), or
53 * 2) the file range lock info (for fcntl F_GETLK results).
54 */
55 struct ceph_mds_reply_info_parsed {
56 struct ceph_mds_reply_head *head;
57
58 /* trace */
59 struct ceph_mds_reply_info_in diri, targeti;
60 struct ceph_mds_reply_dirfrag *dirfrag;
61 char *dname;
62 u32 dname_len;
63 struct ceph_mds_reply_lease *dlease;
64
65 /* extra */
66 union {
67 /* for fcntl F_GETLK results */
68 struct ceph_filelock *filelock_reply;
69
70 /* for readdir results */
71 struct {
72 struct ceph_mds_reply_dirfrag *dir_dir;
73 size_t dir_buf_size;
74 int dir_nr;
75 char **dir_dname;
76 u32 *dir_dname_len;
77 struct ceph_mds_reply_lease **dir_dlease;
78 struct ceph_mds_reply_info_in *dir_in;
79 u8 dir_complete, dir_end;
80 };
81
82 /* for create results */
83 struct {
84 bool has_create_ino;
85 u64 ino;
86 };
87 };
88
89 /* encoded blob describing snapshot contexts for certain
90 operations (e.g., open) */
91 void *snapblob;
92 int snapblob_len;
93 };
94
95
96 /*
97 * cap releases are batched and sent to the MDS en masse.
98 */
99 #define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \
100 sizeof(struct ceph_mds_cap_release)) / \
101 sizeof(struct ceph_mds_cap_item))
102
103
104 /*
105 * state associated with each MDS<->client session
106 */
107 enum {
108 CEPH_MDS_SESSION_NEW = 1,
109 CEPH_MDS_SESSION_OPENING = 2,
110 CEPH_MDS_SESSION_OPEN = 3,
111 CEPH_MDS_SESSION_HUNG = 4,
112 CEPH_MDS_SESSION_CLOSING = 5,
113 CEPH_MDS_SESSION_RESTARTING = 6,
114 CEPH_MDS_SESSION_RECONNECTING = 7,
115 };
116
117 struct ceph_mds_session {
118 struct ceph_mds_client *s_mdsc;
119 int s_mds;
120 int s_state;
121 unsigned long s_ttl; /* time until mds kills us */
122 u64 s_seq; /* incoming msg seq # */
123 struct mutex s_mutex; /* serialize session messages */
124
125 struct ceph_connection s_con;
126
127 struct ceph_auth_handshake s_auth;
128
129 /* protected by s_gen_ttl_lock */
130 spinlock_t s_gen_ttl_lock;
131 u32 s_cap_gen; /* inc each time we get mds stale msg */
132 unsigned long s_cap_ttl; /* when session caps expire */
133
134 /* protected by s_cap_lock */
135 spinlock_t s_cap_lock;
136 struct list_head s_caps; /* all caps issued by this session */
137 int s_nr_caps, s_trim_caps;
138 int s_num_cap_releases;
139 int s_cap_reconnect;
140 int s_readonly;
141 struct list_head s_cap_releases; /* waiting cap_release messages */
142 struct ceph_cap *s_cap_iterator;
143
144 /* protected by mutex */
145 struct list_head s_cap_flushing; /* inodes w/ flushing caps */
146 struct list_head s_cap_snaps_flushing;
147 unsigned long s_renew_requested; /* last time we sent a renew req */
148 u64 s_renew_seq;
149
150 atomic_t s_ref;
151 struct list_head s_waiting; /* waiting requests */
152 struct list_head s_unsafe; /* unsafe requests */
153 };
154
155 /*
156 * modes of choosing which MDS to send a request to
157 */
158 enum {
159 USE_ANY_MDS,
160 USE_RANDOM_MDS,
161 USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
162 };
163
164 struct ceph_mds_request;
165 struct ceph_mds_client;
166
167 /*
168 * request completion callback
169 */
170 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
171 struct ceph_mds_request *req);
172 /*
173 * wait for request completion callback
174 */
175 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
176 struct ceph_mds_request *req);
177
178 /*
179 * an in-flight mds request
180 */
181 struct ceph_mds_request {
182 u64 r_tid; /* transaction id */
183 struct rb_node r_node;
184 struct ceph_mds_client *r_mdsc;
185
186 int r_op; /* mds op code */
187
188 /* operation on what? */
189 struct inode *r_inode; /* arg1 */
190 struct dentry *r_dentry; /* arg1 */
191 struct dentry *r_old_dentry; /* arg2: rename from or link from */
192 struct inode *r_old_dentry_dir; /* arg2: old dentry's parent dir */
193 char *r_path1, *r_path2;
194 struct ceph_vino r_ino1, r_ino2;
195
196 struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
197 struct inode *r_target_inode; /* resulting inode */
198
199 struct mutex r_fill_mutex;
200
201 union ceph_mds_request_args r_args;
202 int r_fmode; /* file mode, if expecting cap */
203 kuid_t r_uid;
204 kgid_t r_gid;
205 struct timespec r_stamp;
206
207 /* for choosing which mds to send this request to */
208 int r_direct_mode;
209 u32 r_direct_hash; /* choose dir frag based on this dentry hash */
210 bool r_direct_is_hash; /* true if r_direct_hash is valid */
211
212 /* data payload is used for xattr ops */
213 struct ceph_pagelist *r_pagelist;
214
215 /* what caps shall we drop? */
216 int r_inode_drop, r_inode_unless;
217 int r_dentry_drop, r_dentry_unless;
218 int r_old_dentry_drop, r_old_dentry_unless;
219 struct inode *r_old_inode;
220 int r_old_inode_drop, r_old_inode_unless;
221
222 struct ceph_msg *r_request; /* original request */
223 int r_request_release_offset;
224 struct ceph_msg *r_reply;
225 struct ceph_mds_reply_info_parsed r_reply_info;
226 struct page *r_locked_page;
227 int r_err;
228 bool r_aborted;
229
230 unsigned long r_timeout; /* optional. jiffies, 0 is "wait forever" */
231 unsigned long r_started; /* start time to measure timeout against */
232 unsigned long r_request_started; /* start time for mds request only,
233 used to measure lease durations */
234
235 /* link unsafe requests to parent directory, for fsync */
236 struct inode *r_unsafe_dir;
237 struct list_head r_unsafe_dir_item;
238
239 /* unsafe requests that modify the target inode */
240 struct list_head r_unsafe_target_item;
241
242 struct ceph_mds_session *r_session;
243
244 int r_attempts; /* resend attempts */
245 int r_num_fwd; /* number of forward attempts */
246 int r_resend_mds; /* mds to resend to next, if any*/
247 u32 r_sent_on_mseq; /* cap mseq request was sent at*/
248
249 struct kref r_kref;
250 struct list_head r_wait;
251 struct completion r_completion;
252 struct completion r_safe_completion;
253 ceph_mds_request_callback_t r_callback;
254 ceph_mds_request_wait_callback_t r_wait_for_completion;
255 struct list_head r_unsafe_item; /* per-session unsafe list item */
256 bool r_got_unsafe, r_got_safe, r_got_result;
257
258 bool r_did_prepopulate;
259 long long r_dir_release_cnt;
260 long long r_dir_ordered_cnt;
261 int r_readdir_cache_idx;
262 u32 r_readdir_offset;
263
264 struct ceph_cap_reservation r_caps_reservation;
265 int r_num_caps;
266 };
267
268 struct ceph_pool_perm {
269 struct rb_node node;
270 u32 pool;
271 int perm;
272 };
273
274 /*
275 * mds client state
276 */
277 struct ceph_mds_client {
278 struct ceph_fs_client *fsc;
279 struct mutex mutex; /* all nested structures */
280
281 struct ceph_mdsmap *mdsmap;
282 struct completion safe_umount_waiters;
283 wait_queue_head_t session_close_wq;
284 struct list_head waiting_for_map;
285
286 struct ceph_mds_session **sessions; /* NULL for mds if no session */
287 atomic_t num_sessions;
288 int max_sessions; /* len of s_mds_sessions */
289 int stopping; /* true if shutting down */
290
291 /*
292 * snap_rwsem will cover cap linkage into snaprealms, and
293 * realm snap contexts. (later, we can do per-realm snap
294 * contexts locks..) the empty list contains realms with no
295 * references (implying they contain no inodes with caps) that
296 * should be destroyed.
297 */
298 u64 last_snap_seq;
299 struct rw_semaphore snap_rwsem;
300 struct rb_root snap_realms;
301 struct list_head snap_empty;
302 spinlock_t snap_empty_lock; /* protect snap_empty */
303
304 u64 last_tid; /* most recent mds request */
305 u64 oldest_tid; /* oldest incomplete mds request,
306 excluding setfilelock requests */
307 struct rb_root request_tree; /* pending mds requests */
308 struct delayed_work delayed_work; /* delayed work */
309 unsigned long last_renew_caps; /* last time we renewed our caps */
310 struct list_head cap_delay_list; /* caps with delayed release */
311 spinlock_t cap_delay_lock; /* protects cap_delay_list */
312 struct list_head snap_flush_list; /* cap_snaps ready to flush */
313 spinlock_t snap_flush_lock;
314
315 u64 last_cap_flush_tid;
316 struct rb_root cap_flush_tree;
317 struct list_head cap_dirty; /* inodes with dirty caps */
318 struct list_head cap_dirty_migrating; /* ...that are migration... */
319 int num_cap_flushing; /* # caps we are flushing */
320 spinlock_t cap_dirty_lock; /* protects above items */
321 wait_queue_head_t cap_flushing_wq;
322
323 /*
324 * Cap reservations
325 *
326 * Maintain a global pool of preallocated struct ceph_caps, referenced
327 * by struct ceph_caps_reservations. This ensures that we preallocate
328 * memory needed to successfully process an MDS response. (If an MDS
329 * sends us cap information and we fail to process it, we will have
330 * problems due to the client and MDS being out of sync.)
331 *
332 * Reservations are 'owned' by a ceph_cap_reservation context.
333 */
334 spinlock_t caps_list_lock;
335 struct list_head caps_list; /* unused (reserved or
336 unreserved) */
337 int caps_total_count; /* total caps allocated */
338 int caps_use_count; /* in use */
339 int caps_reserve_count; /* unused, reserved */
340 int caps_avail_count; /* unused, unreserved */
341 int caps_min_count; /* keep at least this many
342 (unreserved) */
343 spinlock_t dentry_lru_lock;
344 struct list_head dentry_lru;
345 int num_dentry;
346
347 struct rw_semaphore pool_perm_rwsem;
348 struct rb_root pool_perm_tree;
349 };
350
351 extern const char *ceph_mds_op_name(int op);
352
353 extern struct ceph_mds_session *
354 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
355
356 static inline struct ceph_mds_session *
ceph_get_mds_session(struct ceph_mds_session * s)357 ceph_get_mds_session(struct ceph_mds_session *s)
358 {
359 atomic_inc(&s->s_ref);
360 return s;
361 }
362
363 extern const char *ceph_session_state_name(int s);
364
365 extern void ceph_put_mds_session(struct ceph_mds_session *s);
366
367 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
368 struct ceph_msg *msg, int mds);
369
370 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
371 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
372 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
373 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
374
375 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
376
377 extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
378 struct inode *inode,
379 struct dentry *dn);
380
381 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
382 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
383 struct inode *dir);
384 extern struct ceph_mds_request *
385 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
386 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
387 struct ceph_mds_request *req);
388 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
389 struct inode *dir,
390 struct ceph_mds_request *req);
ceph_mdsc_get_request(struct ceph_mds_request * req)391 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
392 {
393 kref_get(&req->r_kref);
394 }
395 extern void ceph_mdsc_release_request(struct kref *kref);
ceph_mdsc_put_request(struct ceph_mds_request * req)396 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
397 {
398 kref_put(&req->r_kref, ceph_mdsc_release_request);
399 }
400
401 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
402 struct ceph_mds_session *session);
403
404 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
405
406 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
407 int stop_on_nosnap);
408
409 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
410 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
411 struct inode *inode,
412 struct dentry *dentry, char action,
413 u32 seq);
414
415 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
416 struct ceph_msg *msg);
417
418 extern struct ceph_mds_session *
419 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
420 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
421 struct ceph_mds_session *session);
422
423 #endif
424