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 /*
  51  * parsed info about an mds reply, including information about
  52  * either: 1) the target inode and/or its parent directory and dentry,
  53  * and directory contents (for readdir results), or
  54  * 2) the file range lock info (for fcntl F_GETLK results).
  55  */
  56 struct ceph_mds_reply_info_parsed {
  57         struct ceph_mds_reply_head    *head;
  58
  59         /* trace */
  60         struct ceph_mds_reply_info_in diri, targeti;
  61         struct ceph_mds_reply_dirfrag *dirfrag;
  62         char                          *dname;
  63         u32                           dname_len;
  64         struct ceph_mds_reply_lease   *dlease;
  65
  66         /* extra */
  67         union {
  68                 /* for fcntl F_GETLK results */
  69                 struct ceph_filelock *filelock_reply;
  70
  71                 /* for readdir results */
  72                 struct {
  73                         struct ceph_mds_reply_dirfrag *dir_dir;
  74                         size_t                        dir_buf_size;
  75                         int                           dir_nr;
  76                         char                          **dir_dname;
  77                         u32                           *dir_dname_len;
  78                         struct ceph_mds_reply_lease   **dir_dlease;
  79                         struct ceph_mds_reply_info_in *dir_in;
  80                         u8                            dir_complete, dir_end;
  81                 };
  82
  83                 /* for create results */
  84                 struct {
  85                         bool has_create_ino;
  86                         u64 ino;
  87                 };
  88         };
  89
  90         /* encoded blob describing snapshot contexts for certain
  91            operations (e.g., open) */
  92         void *snapblob;
  93         int snapblob_len;
  94 };
  95
  96
  97 /*
  98  * cap releases are batched and sent to the MDS en masse.
  99  */
 100 #define CEPH_CAPS_PER_RELEASE ((PAGE_CACHE_SIZE -                       \
 101                                 sizeof(struct ceph_mds_cap_release)) /  \
 102                                sizeof(struct ceph_mds_cap_item))
 103
 104
 105 /*
 106  * state associated with each MDS<->client session
 107  */
 108 enum {
 109         CEPH_MDS_SESSION_NEW = 1,
 110         CEPH_MDS_SESSION_OPENING = 2,
 111         CEPH_MDS_SESSION_OPEN = 3,
 112         CEPH_MDS_SESSION_HUNG = 4,
 113         CEPH_MDS_SESSION_CLOSING = 5,
 114         CEPH_MDS_SESSION_RESTARTING = 6,
 115         CEPH_MDS_SESSION_RECONNECTING = 7,
 116 };
 117
 118 struct ceph_mds_session {
 119         struct ceph_mds_client *s_mdsc;
 120         int               s_mds;
 121         int               s_state;
 122         unsigned long     s_ttl;      /* time until mds kills us */
 123         u64               s_seq;      /* incoming msg seq # */
 124         struct mutex      s_mutex;    /* serialize session messages */
 125
 126         struct ceph_connection s_con;
 127
 128         struct ceph_auth_handshake s_auth;
 129
 130         /* protected by s_gen_ttl_lock */
 131         spinlock_t        s_gen_ttl_lock;
 132         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 133         unsigned long     s_cap_ttl;  /* when session caps expire */
 134
 135         /* protected by s_cap_lock */
 136         spinlock_t        s_cap_lock;
 137         struct list_head  s_caps;     /* all caps issued by this session */
 138         int               s_nr_caps, s_trim_caps;
 139         int               s_num_cap_releases;
 140         int               s_cap_reconnect;
 141         int               s_readonly;
 142         struct list_head  s_cap_releases; /* waiting cap_release messages */
 143         struct ceph_cap  *s_cap_iterator;
 144
 145         /* protected by mutex */
 146         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 147         struct list_head  s_cap_snaps_flushing;
 148         unsigned long     s_renew_requested; /* last time we sent a renew req */
 149         u64               s_renew_seq;
 150
 151         atomic_t          s_ref;
 152         struct list_head  s_waiting;  /* waiting requests */
 153         struct list_head  s_unsafe;   /* unsafe requests */
 154 };
 155
 156 /*
 157  * modes of choosing which MDS to send a request to
 158  */
 159 enum {
 160         USE_ANY_MDS,
 161         USE_RANDOM_MDS,
 162         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 163 };
 164
 165 struct ceph_mds_request;
 166 struct ceph_mds_client;
 167
 168 /*
 169  * request completion callback
 170  */
 171 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 172                                              struct ceph_mds_request *req);
 173 /*
 174  * wait for request completion callback
 175  */
 176 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 177                                                  struct ceph_mds_request *req);
 178
 179 /*
 180  * an in-flight mds request
 181  */
 182 struct ceph_mds_request {
 183         u64 r_tid;                   /* transaction id */
 184         struct rb_node r_node;
 185         struct ceph_mds_client *r_mdsc;
 186
 187         int r_op;                    /* mds op code */
 188
 189         /* operation on what? */
 190         struct inode *r_inode;              /* arg1 */
 191         struct dentry *r_dentry;            /* arg1 */
 192         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 193         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 194         char *r_path1, *r_path2;
 195         struct ceph_vino r_ino1, r_ino2;
 196
 197         struct inode *r_locked_dir; /* dir (if any) i_mutex locked by vfs */
 198         struct inode *r_target_inode;       /* resulting inode */
 199
 200         struct mutex r_fill_mutex;
 201
 202         union ceph_mds_request_args r_args;
 203         int r_fmode;        /* file mode, if expecting cap */
 204         kuid_t r_uid;
 205         kgid_t r_gid;
 206         struct timespec r_stamp;
 207
 208         /* for choosing which mds to send this request to */
 209         int r_direct_mode;
 210         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 211         bool r_direct_is_hash;  /* true if r_direct_hash is valid */
 212
 213         /* data payload is used for xattr ops */
 214         struct ceph_pagelist *r_pagelist;
 215
 216         /* what caps shall we drop? */
 217         int r_inode_drop, r_inode_unless;
 218         int r_dentry_drop, r_dentry_unless;
 219         int r_old_dentry_drop, r_old_dentry_unless;
 220         struct inode *r_old_inode;
 221         int r_old_inode_drop, r_old_inode_unless;
 222
 223         struct ceph_msg  *r_request;  /* original request */
 224         int r_request_release_offset;
 225         struct ceph_msg  *r_reply;
 226         struct ceph_mds_reply_info_parsed r_reply_info;
 227         struct page *r_locked_page;
 228         int r_err;
 229         bool r_aborted;
 230
 231         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 232         unsigned long r_started;  /* start time to measure timeout against */
 233         unsigned long r_request_started; /* start time for mds request only,
 234                                             used to measure lease durations */
 235
 236         /* link unsafe requests to parent directory, for fsync */
 237         struct inode    *r_unsafe_dir;
 238         struct list_head r_unsafe_dir_item;
 239
 240         /* unsafe requests that modify the target inode */
 241         struct list_head r_unsafe_target_item;
 242
 243         struct ceph_mds_session *r_session;
 244
 245         int               r_attempts;   /* resend attempts */
 246         int               r_num_fwd;    /* number of forward attempts */
 247         int               r_resend_mds; /* mds to resend to next, if any*/
 248         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 249
 250         struct kref       r_kref;
 251         struct list_head  r_wait;
 252         struct completion r_completion;
 253         struct completion r_safe_completion;
 254         ceph_mds_request_callback_t r_callback;
 255         ceph_mds_request_wait_callback_t r_wait_for_completion;
 256         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 257         bool              r_got_unsafe, r_got_safe, r_got_result;
 258
 259         bool              r_did_prepopulate;
 260         long long         r_dir_release_cnt;
 261         long long         r_dir_ordered_cnt;
 262         int               r_readdir_cache_idx;
 263         u32               r_readdir_offset;
 264
 265         struct ceph_cap_reservation r_caps_reservation;
 266         int r_num_caps;
 267 };
 268
 269 struct ceph_pool_perm {
 270         struct rb_node node;
 271         u32 pool;
 272         int perm;
 273 };
 274
 275 /*
 276  * mds client state
 277  */
 278 struct ceph_mds_client {
 279         struct ceph_fs_client  *fsc;
 280         struct mutex            mutex;         /* all nested structures */
 281
 282         struct ceph_mdsmap      *mdsmap;
 283         struct completion       safe_umount_waiters;
 284         wait_queue_head_t       session_close_wq;
 285         struct list_head        waiting_for_map;
 286
 287         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 288         atomic_t                num_sessions;
 289         int                     max_sessions;  /* len of s_mds_sessions */
 290         int                     stopping;      /* true if shutting down */
 291
 292         /*
 293          * snap_rwsem will cover cap linkage into snaprealms, and
 294          * realm snap contexts.  (later, we can do per-realm snap
 295          * contexts locks..)  the empty list contains realms with no
 296          * references (implying they contain no inodes with caps) that
 297          * should be destroyed.
 298          */
 299         u64                     last_snap_seq;
 300         struct rw_semaphore     snap_rwsem;
 301         struct rb_root          snap_realms;
 302         struct list_head        snap_empty;
 303         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 304
 305         u64                    last_tid;      /* most recent mds request */
 306         u64                    oldest_tid;    /* oldest incomplete mds request,
 307                                                  excluding setfilelock requests */
 308         struct rb_root         request_tree;  /* pending mds requests */
 309         struct delayed_work    delayed_work;  /* delayed work */
 310         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 311         struct list_head cap_delay_list;   /* caps with delayed release */
 312         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 313         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 314         spinlock_t       snap_flush_lock;
 315
 316         u64               last_cap_flush_tid;
 317         struct rb_root    cap_flush_tree;
 318         struct list_head  cap_dirty;        /* inodes with dirty caps */
 319         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 320         int               num_cap_flushing; /* # caps we are flushing */
 321         spinlock_t        cap_dirty_lock;   /* protects above items */
 322         wait_queue_head_t cap_flushing_wq;
 323
 324         /*
 325          * Cap reservations
 326          *
 327          * Maintain a global pool of preallocated struct ceph_caps, referenced
 328          * by struct ceph_caps_reservations.  This ensures that we preallocate
 329          * memory needed to successfully process an MDS response.  (If an MDS
 330          * sends us cap information and we fail to process it, we will have
 331          * problems due to the client and MDS being out of sync.)
 332          *
 333          * Reservations are 'owned' by a ceph_cap_reservation context.
 334          */
 335         spinlock_t      caps_list_lock;
 336         struct          list_head caps_list; /* unused (reserved or
 337                                                 unreserved) */
 338         int             caps_total_count;    /* total caps allocated */
 339         int             caps_use_count;      /* in use */
 340         int             caps_reserve_count;  /* unused, reserved */
 341         int             caps_avail_count;    /* unused, unreserved */
 342         int             caps_min_count;      /* keep at least this many
 343                                                 (unreserved) */
 344         spinlock_t        dentry_lru_lock;
 345         struct list_head  dentry_lru;
 346         int               num_dentry;
 347
 348         struct rw_semaphore     pool_perm_rwsem;
 349         struct rb_root          pool_perm_tree;
 350 };
 351
 352 extern const char *ceph_mds_op_name(int op);
 353
 354 extern struct ceph_mds_session *
 355 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 356
 357 static inline struct ceph_mds_session *
 358 ceph_get_mds_session(struct ceph_mds_session *s)
 359 {
 360         atomic_inc(&s->s_ref);
 361         return s;
 362 }
 363
 364 extern const char *ceph_session_state_name(int s);
 365
 366 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 367
 368 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 369                              struct ceph_msg *msg, int mds);
 370
 371 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 372 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 373 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 374 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 375
 376 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 377
 378 extern void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc,
 379                                     struct inode *inode,
 380                                     struct dentry *dn);
 381
 382 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 383 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 384                                            struct inode *dir);
 385 extern struct ceph_mds_request *
 386 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 387 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 388                                      struct ceph_mds_request *req);
 389 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 390                                 struct inode *dir,
 391                                 struct ceph_mds_request *req);
 392 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 393 {
 394         kref_get(&req->r_kref);
 395 }
 396 extern void ceph_mdsc_release_request(struct kref *kref);
 397 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 398 {
 399         kref_put(&req->r_kref, ceph_mdsc_release_request);
 400 }
 401
 402 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 403                                    struct ceph_mds_session *session);
 404
 405 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 406
 407 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 408                                   int stop_on_nosnap);
 409
 410 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 411 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 412                                      struct inode *inode,
 413                                      struct dentry *dentry, char action,
 414                                      u32 seq);
 415
 416 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
 417                                  struct ceph_msg *msg);
 418
 419 extern struct ceph_mds_session *
 420 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 421 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 422                                           struct ceph_mds_session *session);
 423
 424 #endif