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