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 * 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); 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); 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