fs/ceph/mds_client.h

   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         u64 inline_version;
  45         u32 inline_len;
  46         char *inline_data;
  47         u32 pool_ns_len;
  48 };
  49
  50 struct ceph_mds_reply_dir_entry {
  51         char                          *name;
  52         u32                           name_len;
  53         struct ceph_mds_reply_lease   *lease;
  54         struct ceph_mds_reply_info_in inode;
  55         loff_t                        offset;
  56 };
  57
  58 /*
  59  * parsed info about an mds reply, including information about
  60  * either: 1) the target inode and/or its parent directory and dentry,
  61  * and directory contents (for readdir results), or
  62  * 2) the file range lock info (for fcntl F_GETLK results).
  63  */
  64 struct ceph_mds_reply_info_parsed {
  65         struct ceph_mds_reply_head    *head;
  66
  67         /* trace */
  68         struct ceph_mds_reply_info_in diri, targeti;
  69         struct ceph_mds_reply_dirfrag *dirfrag;
  70         char                          *dname;
  71         u32                           dname_len;
  72         struct ceph_mds_reply_lease   *dlease;
  73
  74         /* extra */
  75         union {
  76                 /* for fcntl F_GETLK results */
  77                 struct ceph_filelock *filelock_reply;
  78
  79                 /* for readdir results */
  80                 struct {
  81                         struct ceph_mds_reply_dirfrag *dir_dir;
  82                         size_t                        dir_buf_size;
  83                         int                           dir_nr;
  84                         bool                          dir_complete;
  85                         bool                          dir_end;
  86                         bool                          hash_order;
  87                         struct ceph_mds_reply_dir_entry  *dir_entries;
  88                 };
  89
  90                 /* for create results */
  91                 struct {
  92                         bool has_create_ino;
  93                         u64 ino;
  94                 };
  95         };
  96
  97         /* encoded blob describing snapshot contexts for certain
  98            operations (e.g., open) */
  99         void *snapblob;
 100         int snapblob_len;
 101 };
 102
 103
 104 /*
 105  * cap releases are batched and sent to the MDS en masse.
 106  */
 107 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE -                     \
 108                                 sizeof(struct ceph_mds_cap_release)) /  \
 109                                sizeof(struct ceph_mds_cap_item))
 110
 111
 112 /*
 113  * state associated with each MDS<->client session
 114  */
 115 enum {
 116         CEPH_MDS_SESSION_NEW = 1,
 117         CEPH_MDS_SESSION_OPENING = 2,
 118         CEPH_MDS_SESSION_OPEN = 3,
 119         CEPH_MDS_SESSION_HUNG = 4,
 120         CEPH_MDS_SESSION_CLOSING = 5,
 121         CEPH_MDS_SESSION_RESTARTING = 6,
 122         CEPH_MDS_SESSION_RECONNECTING = 7,
 123 };
 124
 125 struct ceph_mds_session {
 126         struct ceph_mds_client *s_mdsc;
 127         int               s_mds;
 128         int               s_state;
 129         unsigned long     s_ttl;      /* time until mds kills us */
 130         u64               s_seq;      /* incoming msg seq # */
 131         struct mutex      s_mutex;    /* serialize session messages */
 132
 133         struct ceph_connection s_con;
 134
 135         struct ceph_auth_handshake s_auth;
 136
 137         /* protected by s_gen_ttl_lock */
 138         spinlock_t        s_gen_ttl_lock;
 139         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 140         unsigned long     s_cap_ttl;  /* when session caps expire */
 141
 142         /* protected by s_cap_lock */
 143         spinlock_t        s_cap_lock;
 144         struct list_head  s_caps;     /* all caps issued by this session */
 145         int               s_nr_caps, s_trim_caps;
 146         int               s_num_cap_releases;
 147         int               s_cap_reconnect;
 148         int               s_readonly;
 149         struct list_head  s_cap_releases; /* waiting cap_release messages */
 150         struct ceph_cap  *s_cap_iterator;
 151
 152         /* protected by mutex */
 153         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 154         struct list_head  s_cap_snaps_flushing;
 155         unsigned long     s_renew_requested; /* last time we sent a renew req */
 156         u64               s_renew_seq;
 157
 158         atomic_t          s_ref;
 159         struct list_head  s_waiting;  /* waiting requests */
 160         struct list_head  s_unsafe;   /* unsafe requests */
 161 };
 162
 163 /*
 164  * modes of choosing which MDS to send a request to
 165  */
 166 enum {
 167         USE_ANY_MDS,
 168         USE_RANDOM_MDS,
 169         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 170 };
 171
 172 struct ceph_mds_request;
 173 struct ceph_mds_client;
 174
 175 /*
 176  * request completion callback
 177  */
 178 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 179                                              struct ceph_mds_request *req);
 180 /*
 181  * wait for request completion callback
 182  */
 183 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 184                                                  struct ceph_mds_request *req);
 185
 186 /*
 187  * an in-flight mds request
 188  */
 189 struct ceph_mds_request {
 190         u64 r_tid;                   /* transaction id */
 191         struct rb_node r_node;
 192         struct ceph_mds_client *r_mdsc;
 193
 194         int r_op;                    /* mds op code */
 195
 196         /* operation on what? */
 197         struct inode *r_inode;              /* arg1 */
 198         struct dentry *r_dentry;            /* arg1 */
 199         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 200         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 201         char *r_path1, *r_path2;
 202         struct ceph_vino r_ino1, r_ino2;
 203
 204         struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
 205         struct inode *r_target_inode;       /* resulting inode */
 206
 207         struct mutex r_fill_mutex;
 208
 209         union ceph_mds_request_args r_args;
 210         int r_fmode;        /* file mode, if expecting cap */
 211         kuid_t r_uid;
 212         kgid_t r_gid;
 213         struct timespec r_stamp;
 214
 215         /* for choosing which mds to send this request to */
 216         int r_direct_mode;
 217         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 218         bool r_direct_is_hash;  /* true if r_direct_hash is valid */
 219
 220         /* data payload is used for xattr ops */
 221         struct ceph_pagelist *r_pagelist;
 222
 223         /* what caps shall we drop? */
 224         int r_inode_drop, r_inode_unless;
 225         int r_dentry_drop, r_dentry_unless;
 226         int r_old_dentry_drop, r_old_dentry_unless;
 227         struct inode *r_old_inode;
 228         int r_old_inode_drop, r_old_inode_unless;
 229
 230         struct ceph_msg  *r_request;  /* original request */
 231         int r_request_release_offset;
 232         struct ceph_msg  *r_reply;
 233         struct ceph_mds_reply_info_parsed r_reply_info;
 234         struct page *r_locked_page;
 235         int r_err;
 236         bool r_aborted;
 237
 238         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 239         unsigned long r_started;  /* start time to measure timeout against */
 240         unsigned long r_request_started; /* start time for mds request only,
 241                                             used to measure lease durations */
 242
 243         /* link unsafe requests to parent directory, for fsync */
 244         struct inode    *r_unsafe_dir;
 245         struct list_head r_unsafe_dir_item;
 246
 247         /* unsafe requests that modify the target inode */
 248         struct list_head r_unsafe_target_item;
 249
 250         struct ceph_mds_session *r_session;
 251
 252         int               r_attempts;   /* resend attempts */
 253         int               r_num_fwd;    /* number of forward attempts */
 254         int               r_resend_mds; /* mds to resend to next, if any*/
 255         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 256
 257         struct kref       r_kref;
 258         struct list_head  r_wait;
 259         struct completion r_completion;
 260         struct completion r_safe_completion;
 261         ceph_mds_request_callback_t r_callback;
 262         ceph_mds_request_wait_callback_t r_wait_for_completion;
 263         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 264         bool              r_got_unsafe, r_got_safe, r_got_result;
 265
 266         bool              r_did_prepopulate;
 267         long long         r_dir_release_cnt;
 268         long long         r_dir_ordered_cnt;
 269         int               r_readdir_cache_idx;
 270         u32               r_readdir_offset;
 271
 272         struct ceph_cap_reservation r_caps_reservation;
 273         int r_num_caps;
 274 };
 275
 276 struct ceph_pool_perm {
 277         struct rb_node node;
 278         u32 pool;
 279         int perm;
 280 };
 281
 282 /*
 283  * mds client state
 284  */
 285 struct ceph_mds_client {
 286         struct ceph_fs_client  *fsc;
 287         struct mutex            mutex;         /* all nested structures */
 288
 289         struct ceph_mdsmap      *mdsmap;
 290         struct completion       safe_umount_waiters;
 291         wait_queue_head_t       session_close_wq;
 292         struct list_head        waiting_for_map;
 293
 294         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 295         atomic_t                num_sessions;
 296         int                     max_sessions;  /* len of s_mds_sessions */
 297         int                     stopping;      /* true if shutting down */
 298
 299         /*
 300          * snap_rwsem will cover cap linkage into snaprealms, and
 301          * realm snap contexts.  (later, we can do per-realm snap
 302          * contexts locks..)  the empty list contains realms with no
 303          * references (implying they contain no inodes with caps) that
 304          * should be destroyed.
 305          */
 306         u64                     last_snap_seq;
 307         struct rw_semaphore     snap_rwsem;
 308         struct rb_root          snap_realms;
 309         struct list_head        snap_empty;
 310         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 311
 312         u64                    last_tid;      /* most recent mds request */
 313         u64                    oldest_tid;    /* oldest incomplete mds request,
 314                                                  excluding setfilelock requests */
 315         struct rb_root         request_tree;  /* pending mds requests */
 316         struct delayed_work    delayed_work;  /* delayed work */
 317         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 318         struct list_head cap_delay_list;   /* caps with delayed release */
 319         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 320         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 321         spinlock_t       snap_flush_lock;
 322
 323         u64               last_cap_flush_tid;
 324         struct rb_root    cap_flush_tree;
 325         struct list_head  cap_dirty;        /* inodes with dirty caps */
 326         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 327         int               num_cap_flushing; /* # caps we are flushing */
 328         spinlock_t        cap_dirty_lock;   /* protects above items */
 329         wait_queue_head_t cap_flushing_wq;
 330
 331         /*
 332          * Cap reservations
 333          *
 334          * Maintain a global pool of preallocated struct ceph_caps, referenced
 335          * by struct ceph_caps_reservations.  This ensures that we preallocate
 336          * memory needed to successfully process an MDS response.  (If an MDS
 337          * sends us cap information and we fail to process it, we will have
 338          * problems due to the client and MDS being out of sync.)
 339          *
 340          * Reservations are 'owned' by a ceph_cap_reservation context.
 341          */
 342         spinlock_t      caps_list_lock;
 343         struct          list_head caps_list; /* unused (reserved or
 344                                                 unreserved) */
 345         int             caps_total_count;    /* total caps allocated */
 346         int             caps_use_count;      /* in use */
 347         int             caps_reserve_count;  /* unused, reserved */
 348         int             caps_avail_count;    /* unused, unreserved */
 349         int             caps_min_count;      /* keep at least this many
 350                                                 (unreserved) */
 351         spinlock_t        dentry_lru_lock;
 352         struct list_head  dentry_lru;
 353         int               num_dentry;
 354
 355         struct rw_semaphore     pool_perm_rwsem;
 356         struct rb_root          pool_perm_tree;
 357 };
 358
 359 extern const char *ceph_mds_op_name(int op);
 360
 361 extern struct ceph_mds_session *
 362 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 363
 364 static inline struct ceph_mds_session *
 365 ceph_get_mds_session(struct ceph_mds_session *s)
 366 {
 367         atomic_inc(&s->s_ref);
 368         return s;
 369 }
 370
 371 extern const char *ceph_session_state_name(int s);
 372
 373 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 374
 375 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 376                              struct ceph_msg *msg, int mds);
 377
 378 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 379 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 380 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 381 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 382
 383 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 384
 385 extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
 386                                     struct inode *inode,
 387                                     struct dentry *dn);
 388
 389 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 390 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 391                                            struct inode *dir);
 392 extern struct ceph_mds_request *
 393 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 394 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 395                                      struct ceph_mds_request *req);
 396 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 397                                 struct inode *dir,
 398                                 struct ceph_mds_request *req);
 399 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 400 {
 401         kref_get(&req->r_kref);
 402 }
 403 extern void ceph_mdsc_release_request(struct kref *kref);
 404 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 405 {
 406         kref_put(&req->r_kref, ceph_mdsc_release_request);
 407 }
 408
 409 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 410                                    struct ceph_mds_session *session);
 411
 412 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 413
 414 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 415                                   int stop_on_nosnap);
 416
 417 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 418 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 419                                      struct inode *inode,
 420                                      struct dentry *dentry, char action,
 421                                      u32 seq);
 422
 423 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
 424                                  struct ceph_msg *msg);
 425
 426 extern struct ceph_mds_session *
 427 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 428 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 429                                           struct ceph_mds_session *session);
 430
 431 #endif