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