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Sage Weil2f2dc052009-10-06 11:31:09 -07001#ifndef _FS_CEPH_MDS_CLIENT_H
2#define _FS_CEPH_MDS_CLIENT_H
3
4#include <linux/completion.h>
Sage Weil153c8e62009-12-07 12:31:09 -08005#include <linux/kref.h>
Sage Weil2f2dc052009-10-06 11:31:09 -07006#include <linux/list.h>
7#include <linux/mutex.h>
8#include <linux/radix-tree.h>
9#include <linux/spinlock.h>
10
11#include "types.h"
12#include "messenger.h"
13#include "mdsmap.h"
14
15/*
16 * Some lock dependencies:
17 *
18 * session->s_mutex
19 * mdsc->mutex
20 *
21 * mdsc->snap_rwsem
22 *
23 * inode->i_lock
24 * mdsc->snap_flush_lock
25 * mdsc->cap_delay_lock
26 *
27 */
28
29struct ceph_client;
30struct ceph_cap;
31
32/*
33 * parsed info about a single inode. pointers are into the encoded
34 * on-wire structures within the mds reply message payload.
35 */
36struct ceph_mds_reply_info_in {
37 struct ceph_mds_reply_inode *in;
38 u32 symlink_len;
39 char *symlink;
40 u32 xattr_len;
41 char *xattr_data;
42};
43
44/*
45 * parsed info about an mds reply, including information about the
46 * target inode and/or its parent directory and dentry, and directory
47 * contents (for readdir results).
48 */
49struct ceph_mds_reply_info_parsed {
50 struct ceph_mds_reply_head *head;
51
52 struct ceph_mds_reply_info_in diri, targeti;
53 struct ceph_mds_reply_dirfrag *dirfrag;
54 char *dname;
55 u32 dname_len;
56 struct ceph_mds_reply_lease *dlease;
57
58 struct ceph_mds_reply_dirfrag *dir_dir;
59 int dir_nr;
60 char **dir_dname;
61 u32 *dir_dname_len;
62 struct ceph_mds_reply_lease **dir_dlease;
63 struct ceph_mds_reply_info_in *dir_in;
64 u8 dir_complete, dir_end;
65
66 /* encoded blob describing snapshot contexts for certain
67 operations (e.g., open) */
68 void *snapblob;
69 int snapblob_len;
70};
71
72
73/*
74 * cap releases are batched and sent to the MDS en masse.
75 */
76#define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE - \
77 sizeof(struct ceph_mds_cap_release)) / \
78 sizeof(struct ceph_mds_cap_item))
79
80
81/*
82 * state associated with each MDS<->client session
83 */
84enum {
85 CEPH_MDS_SESSION_NEW = 1,
86 CEPH_MDS_SESSION_OPENING = 2,
87 CEPH_MDS_SESSION_OPEN = 3,
88 CEPH_MDS_SESSION_HUNG = 4,
89 CEPH_MDS_SESSION_CLOSING = 5,
90 CEPH_MDS_SESSION_RESTARTING = 6,
91 CEPH_MDS_SESSION_RECONNECTING = 7,
92};
93
94struct ceph_mds_session {
95 struct ceph_mds_client *s_mdsc;
96 int s_mds;
97 int s_state;
98 unsigned long s_ttl; /* time until mds kills us */
99 u64 s_seq; /* incoming msg seq # */
100 struct mutex s_mutex; /* serialize session messages */
101
Sage Weil2f2dc052009-10-06 11:31:09 -0700102 struct ceph_connection s_con;
103
Sage Weil4e7a5dc2009-11-18 16:19:57 -0800104 struct ceph_authorizer *s_authorizer;
105 void *s_authorizer_buf, *s_authorizer_reply_buf;
106 size_t s_authorizer_buf_len, s_authorizer_reply_buf_len;
107
Sage Weil2f2dc052009-10-06 11:31:09 -0700108 /* protected by s_cap_lock */
109 spinlock_t s_cap_lock;
110 u32 s_cap_gen; /* inc each time we get mds stale msg */
111 unsigned long s_cap_ttl; /* when session caps expire */
112 struct list_head s_caps; /* all caps issued by this session */
113 int s_nr_caps, s_trim_caps;
114 int s_num_cap_releases;
115 struct list_head s_cap_releases; /* waiting cap_release messages */
116 struct list_head s_cap_releases_done; /* ready to send */
117
118 /* protected by mutex */
119 struct list_head s_cap_flushing; /* inodes w/ flushing caps */
120 struct list_head s_cap_snaps_flushing;
121 unsigned long s_renew_requested; /* last time we sent a renew req */
122 u64 s_renew_seq;
123
124 atomic_t s_ref;
125 struct list_head s_waiting; /* waiting requests */
126 struct list_head s_unsafe; /* unsafe requests */
127};
128
129/*
130 * modes of choosing which MDS to send a request to
131 */
132enum {
133 USE_ANY_MDS,
134 USE_RANDOM_MDS,
135 USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */
136};
137
138struct ceph_mds_request;
139struct ceph_mds_client;
140
141/*
142 * request completion callback
143 */
144typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
145 struct ceph_mds_request *req);
146
147/*
148 * an in-flight mds request
149 */
150struct ceph_mds_request {
151 u64 r_tid; /* transaction id */
152
153 int r_op; /* mds op code */
154 int r_mds;
155
156 /* operation on what? */
157 struct inode *r_inode; /* arg1 */
158 struct dentry *r_dentry; /* arg1 */
159 struct dentry *r_old_dentry; /* arg2: rename from or link from */
160 char *r_path1, *r_path2;
161 struct ceph_vino r_ino1, r_ino2;
162
163 struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
164 struct inode *r_target_inode; /* resulting inode */
165
166 union ceph_mds_request_args r_args;
167 int r_fmode; /* file mode, if expecting cap */
168
169 /* for choosing which mds to send this request to */
170 int r_direct_mode;
171 u32 r_direct_hash; /* choose dir frag based on this dentry hash */
172 bool r_direct_is_hash; /* true if r_direct_hash is valid */
173
174 /* data payload is used for xattr ops */
175 struct page **r_pages;
176 int r_num_pages;
177 int r_data_len;
178
179 /* what caps shall we drop? */
180 int r_inode_drop, r_inode_unless;
181 int r_dentry_drop, r_dentry_unless;
182 int r_old_dentry_drop, r_old_dentry_unless;
183 struct inode *r_old_inode;
184 int r_old_inode_drop, r_old_inode_unless;
185
186 struct ceph_msg *r_request; /* original request */
187 struct ceph_msg *r_reply;
188 struct ceph_mds_reply_info_parsed r_reply_info;
189 int r_err;
190
191 unsigned long r_timeout; /* optional. jiffies */
192 unsigned long r_started; /* start time to measure timeout against */
193 unsigned long r_request_started; /* start time for mds request only,
194 used to measure lease durations */
195
196 /* link unsafe requests to parent directory, for fsync */
197 struct inode *r_unsafe_dir;
198 struct list_head r_unsafe_dir_item;
199
200 struct ceph_mds_session *r_session;
201
202 int r_attempts; /* resend attempts */
203 int r_num_fwd; /* number of forward attempts */
204 int r_num_stale;
205 int r_resend_mds; /* mds to resend to next, if any*/
206
Sage Weil153c8e62009-12-07 12:31:09 -0800207 struct kref r_kref;
Sage Weil2f2dc052009-10-06 11:31:09 -0700208 struct list_head r_wait;
209 struct completion r_completion;
210 struct completion r_safe_completion;
211 ceph_mds_request_callback_t r_callback;
212 struct list_head r_unsafe_item; /* per-session unsafe list item */
213 bool r_got_unsafe, r_got_safe;
214
215 bool r_did_prepopulate;
216 u32 r_readdir_offset;
217
218 struct ceph_cap_reservation r_caps_reservation;
219 int r_num_caps;
220};
221
222/*
223 * mds client state
224 */
225struct ceph_mds_client {
226 struct ceph_client *client;
227 struct mutex mutex; /* all nested structures */
228
229 struct ceph_mdsmap *mdsmap;
230 struct completion safe_umount_waiters, session_close_waiters;
231 struct list_head waiting_for_map;
232
233 struct ceph_mds_session **sessions; /* NULL for mds if no session */
234 int max_sessions; /* len of s_mds_sessions */
235 int stopping; /* true if shutting down */
236
237 /*
238 * snap_rwsem will cover cap linkage into snaprealms, and
239 * realm snap contexts. (later, we can do per-realm snap
240 * contexts locks..) the empty list contains realms with no
241 * references (implying they contain no inodes with caps) that
242 * should be destroyed.
243 */
244 struct rw_semaphore snap_rwsem;
245 struct radix_tree_root snap_realms;
246 struct list_head snap_empty;
247 spinlock_t snap_empty_lock; /* protect snap_empty */
248
249 u64 last_tid; /* most recent mds request */
250 struct radix_tree_root request_tree; /* pending mds requests */
251 struct delayed_work delayed_work; /* delayed work */
252 unsigned long last_renew_caps; /* last time we renewed our caps */
253 struct list_head cap_delay_list; /* caps with delayed release */
254 spinlock_t cap_delay_lock; /* protects cap_delay_list */
255 struct list_head snap_flush_list; /* cap_snaps ready to flush */
256 spinlock_t snap_flush_lock;
257
258 u64 cap_flush_seq;
259 struct list_head cap_dirty; /* inodes with dirty caps */
260 int num_cap_flushing; /* # caps we are flushing */
261 spinlock_t cap_dirty_lock; /* protects above items */
262 wait_queue_head_t cap_flushing_wq;
263
Sage Weil039934b2009-11-12 15:05:52 -0800264#ifdef CONFIG_DEBUG_FS
Sage Weil2f2dc052009-10-06 11:31:09 -0700265 struct dentry *debugfs_file;
Sage Weil039934b2009-11-12 15:05:52 -0800266#endif
Sage Weil2f2dc052009-10-06 11:31:09 -0700267
268 spinlock_t dentry_lru_lock;
269 struct list_head dentry_lru;
270 int num_dentry;
271};
272
273extern const char *ceph_mds_op_name(int op);
274
275extern struct ceph_mds_session *
276__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
277
278static inline struct ceph_mds_session *
279ceph_get_mds_session(struct ceph_mds_session *s)
280{
281 atomic_inc(&s->s_ref);
282 return s;
283}
284
285extern void ceph_put_mds_session(struct ceph_mds_session *s);
286
287extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
288 struct ceph_msg *msg, int mds);
289
Sage Weil5f44f142009-11-18 14:52:18 -0800290extern int ceph_mdsc_init(struct ceph_mds_client *mdsc,
Sage Weil2f2dc052009-10-06 11:31:09 -0700291 struct ceph_client *client);
292extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
293extern void ceph_mdsc_stop(struct ceph_mds_client *mdsc);
294
295extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
296
297extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
298 struct inode *inode,
299 struct dentry *dn, int mask);
300
301extern struct ceph_mds_request *
302ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
303extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
304 struct ceph_mds_request *req);
305extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
306 struct inode *dir,
307 struct ceph_mds_request *req);
308static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
309{
Sage Weil153c8e62009-12-07 12:31:09 -0800310 kref_get(&req->r_kref);
Sage Weil2f2dc052009-10-06 11:31:09 -0700311}
Sage Weil153c8e62009-12-07 12:31:09 -0800312extern void ceph_mdsc_release_request(struct kref *kref);
313static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
314{
315 kref_put(&req->r_kref, ceph_mdsc_release_request);
316}
Sage Weil2f2dc052009-10-06 11:31:09 -0700317
318extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
319
320extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
321 int stop_on_nosnap);
322
323extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
324extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
325 struct inode *inode,
326 struct dentry *dentry, char action,
327 u32 seq);
328
329extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
330 struct ceph_msg *msg);
331
332#endif