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 "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 29 struct ceph_client; 30 struct 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 */ 36 struct 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 */ 49 struct 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 */ 84 enum { 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 94 struct 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 */ 101 102 struct ceph_connection s_con; 103 104 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; 107 108 /* 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 struct ceph_cap *s_cap_iterator; 118 119 /* protected by mutex */ 120 struct list_head s_cap_flushing; /* inodes w/ flushing caps */ 121 struct list_head s_cap_snaps_flushing; 122 unsigned long s_renew_requested; /* last time we sent a renew req */ 123 u64 s_renew_seq; 124 125 atomic_t s_ref; 126 struct list_head s_waiting; /* waiting requests */ 127 struct list_head s_unsafe; /* unsafe requests */ 128 }; 129 130 /* 131 * modes of choosing which MDS to send a request to 132 */ 133 enum { 134 USE_ANY_MDS, 135 USE_RANDOM_MDS, 136 USE_AUTH_MDS, /* prefer authoritative mds for this metadata item */ 137 }; 138 139 struct ceph_mds_request; 140 struct ceph_mds_client; 141 142 /* 143 * request completion callback 144 */ 145 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc, 146 struct ceph_mds_request *req); 147 148 /* 149 * an in-flight mds request 150 */ 151 struct ceph_mds_request { 152 u64 r_tid; /* transaction id */ 153 struct rb_node r_node; 154 struct ceph_mds_client *r_mdsc; 155 156 int r_op; /* mds op code */ 157 int r_mds; 158 159 /* operation on what? */ 160 struct inode *r_inode; /* arg1 */ 161 struct dentry *r_dentry; /* arg1 */ 162 struct dentry *r_old_dentry; /* arg2: rename from or link from */ 163 char *r_path1, *r_path2; 164 struct ceph_vino r_ino1, r_ino2; 165 166 struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */ 167 struct inode *r_target_inode; /* resulting inode */ 168 169 struct mutex r_fill_mutex; 170 171 union ceph_mds_request_args r_args; 172 int r_fmode; /* file mode, if expecting cap */ 173 174 /* for choosing which mds to send this request to */ 175 int r_direct_mode; 176 u32 r_direct_hash; /* choose dir frag based on this dentry hash */ 177 bool r_direct_is_hash; /* true if r_direct_hash is valid */ 178 179 /* data payload is used for xattr ops */ 180 struct page **r_pages; 181 int r_num_pages; 182 int r_data_len; 183 184 /* what caps shall we drop? */ 185 int r_inode_drop, r_inode_unless; 186 int r_dentry_drop, r_dentry_unless; 187 int r_old_dentry_drop, r_old_dentry_unless; 188 struct inode *r_old_inode; 189 int r_old_inode_drop, r_old_inode_unless; 190 191 struct ceph_msg *r_request; /* original request */ 192 int r_request_release_offset; 193 struct ceph_msg *r_reply; 194 struct ceph_mds_reply_info_parsed r_reply_info; 195 int r_err; 196 bool r_aborted; 197 198 unsigned long r_timeout; /* optional. jiffies */ 199 unsigned long r_started; /* start time to measure timeout against */ 200 unsigned long r_request_started; /* start time for mds request only, 201 used to measure lease durations */ 202 203 /* link unsafe requests to parent directory, for fsync */ 204 struct inode *r_unsafe_dir; 205 struct list_head r_unsafe_dir_item; 206 207 struct ceph_mds_session *r_session; 208 209 int r_attempts; /* resend attempts */ 210 int r_num_fwd; /* number of forward attempts */ 211 int r_resend_mds; /* mds to resend to next, if any*/ 212 u32 r_sent_on_mseq; /* cap mseq request was sent at*/ 213 214 struct kref r_kref; 215 struct list_head r_wait; 216 struct completion r_completion; 217 struct completion r_safe_completion; 218 ceph_mds_request_callback_t r_callback; 219 struct list_head r_unsafe_item; /* per-session unsafe list item */ 220 bool r_got_unsafe, r_got_safe, r_got_result; 221 222 bool r_did_prepopulate; 223 u32 r_readdir_offset; 224 225 struct ceph_cap_reservation r_caps_reservation; 226 int r_num_caps; 227 }; 228 229 /* 230 * mds client state 231 */ 232 struct ceph_mds_client { 233 struct ceph_client *client; 234 struct mutex mutex; /* all nested structures */ 235 236 struct ceph_mdsmap *mdsmap; 237 struct completion safe_umount_waiters, session_close_waiters; 238 struct list_head waiting_for_map; 239 240 struct ceph_mds_session **sessions; /* NULL for mds if no session */ 241 int max_sessions; /* len of s_mds_sessions */ 242 int stopping; /* true if shutting down */ 243 244 /* 245 * snap_rwsem will cover cap linkage into snaprealms, and 246 * realm snap contexts. (later, we can do per-realm snap 247 * contexts locks..) the empty list contains realms with no 248 * references (implying they contain no inodes with caps) that 249 * should be destroyed. 250 */ 251 struct rw_semaphore snap_rwsem; 252 struct rb_root snap_realms; 253 struct list_head snap_empty; 254 spinlock_t snap_empty_lock; /* protect snap_empty */ 255 256 u64 last_tid; /* most recent mds request */ 257 struct rb_root request_tree; /* pending mds requests */ 258 struct delayed_work delayed_work; /* delayed work */ 259 unsigned long last_renew_caps; /* last time we renewed our caps */ 260 struct list_head cap_delay_list; /* caps with delayed release */ 261 spinlock_t cap_delay_lock; /* protects cap_delay_list */ 262 struct list_head snap_flush_list; /* cap_snaps ready to flush */ 263 spinlock_t snap_flush_lock; 264 265 u64 cap_flush_seq; 266 struct list_head cap_dirty; /* inodes with dirty caps */ 267 int num_cap_flushing; /* # caps we are flushing */ 268 spinlock_t cap_dirty_lock; /* protects above items */ 269 wait_queue_head_t cap_flushing_wq; 270 271 /* 272 * Cap reservations 273 * 274 * Maintain a global pool of preallocated struct ceph_caps, referenced 275 * by struct ceph_caps_reservations. This ensures that we preallocate 276 * memory needed to successfully process an MDS response. (If an MDS 277 * sends us cap information and we fail to process it, we will have 278 * problems due to the client and MDS being out of sync.) 279 * 280 * Reservations are 'owned' by a ceph_cap_reservation context. 281 */ 282 spinlock_t caps_list_lock; 283 struct list_head caps_list; /* unused (reserved or 284 unreserved) */ 285 int caps_total_count; /* total caps allocated */ 286 int caps_use_count; /* in use */ 287 int caps_reserve_count; /* unused, reserved */ 288 int caps_avail_count; /* unused, unreserved */ 289 int caps_min_count; /* keep at least this many 290 (unreserved) */ 291 292 #ifdef CONFIG_DEBUG_FS 293 struct dentry *debugfs_file; 294 #endif 295 296 spinlock_t dentry_lru_lock; 297 struct list_head dentry_lru; 298 int num_dentry; 299 }; 300 301 extern const char *ceph_mds_op_name(int op); 302 303 extern struct ceph_mds_session * 304 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds); 305 306 static inline struct ceph_mds_session * 307 ceph_get_mds_session(struct ceph_mds_session *s) 308 { 309 atomic_inc(&s->s_ref); 310 return s; 311 } 312 313 extern void ceph_put_mds_session(struct ceph_mds_session *s); 314 315 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc, 316 struct ceph_msg *msg, int mds); 317 318 extern int ceph_mdsc_init(struct ceph_mds_client *mdsc, 319 struct ceph_client *client); 320 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc); 321 extern void ceph_mdsc_stop(struct ceph_mds_client *mdsc); 322 323 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc); 324 325 extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, 326 struct inode *inode, 327 struct dentry *dn, int mask); 328 329 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req); 330 331 extern struct ceph_mds_request * 332 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode); 333 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, 334 struct ceph_mds_request *req); 335 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc, 336 struct inode *dir, 337 struct ceph_mds_request *req); 338 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req) 339 { 340 kref_get(&req->r_kref); 341 } 342 extern void ceph_mdsc_release_request(struct kref *kref); 343 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req) 344 { 345 kref_put(&req->r_kref, ceph_mdsc_release_request); 346 } 347 348 extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc, 349 struct ceph_mds_session *session); 350 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc, 351 struct ceph_mds_session *session); 352 353 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc); 354 355 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base, 356 int stop_on_nosnap); 357 358 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry); 359 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session, 360 struct inode *inode, 361 struct dentry *dentry, char action, 362 u32 seq); 363 364 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, 365 struct ceph_msg *msg); 366 367 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc, 368 struct ceph_mds_session *session); 369 370 #endif 371