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 #include <linux/refcount.h>
  11
  12 #include <linux/ceph/types.h>
  13 #include <linux/ceph/messenger.h>
  14 #include <linux/ceph/mdsmap.h>
  15 #include <linux/ceph/auth.h>
  16
  17 /*
  18  * Some lock dependencies:
  19  *
  20  * session->s_mutex
  21  *         mdsc->mutex
  22  *
  23  *         mdsc->snap_rwsem
  24  *
  25  *         ci->i_ceph_lock
  26  *                 mdsc->snap_flush_lock
  27  *                 mdsc->cap_delay_lock
  28  *
  29  */
  30
  31 struct ceph_fs_client;
  32 struct ceph_cap;
  33
  34 /*
  35  * parsed info about a single inode.  pointers are into the encoded
  36  * on-wire structures within the mds reply message payload.
  37  */
  38 struct ceph_mds_reply_info_in {
  39         struct ceph_mds_reply_inode *in;
  40         struct ceph_dir_layout dir_layout;
  41         u32 symlink_len;
  42         char *symlink;
  43         u32 xattr_len;
  44         char *xattr_data;
  45         u64 inline_version;
  46         u32 inline_len;
  47         char *inline_data;
  48         u32 pool_ns_len;
  49         char *pool_ns_data;
  50 };
  51
  52 struct ceph_mds_reply_dir_entry {
  53         char                          *name;
  54         u32                           name_len;
  55         struct ceph_mds_reply_lease   *lease;
  56         struct ceph_mds_reply_info_in inode;
  57         loff_t                        offset;
  58 };
  59
  60 /*
  61  * parsed info about an mds reply, including information about
  62  * either: 1) the target inode and/or its parent directory and dentry,
  63  * and directory contents (for readdir results), or
  64  * 2) the file range lock info (for fcntl F_GETLK results).
  65  */
  66 struct ceph_mds_reply_info_parsed {
  67         struct ceph_mds_reply_head    *head;
  68
  69         /* trace */
  70         struct ceph_mds_reply_info_in diri, targeti;
  71         struct ceph_mds_reply_dirfrag *dirfrag;
  72         char                          *dname;
  73         u32                           dname_len;
  74         struct ceph_mds_reply_lease   *dlease;
  75
  76         /* extra */
  77         union {
  78                 /* for fcntl F_GETLK results */
  79                 struct ceph_filelock *filelock_reply;
  80
  81                 /* for readdir results */
  82                 struct {
  83                         struct ceph_mds_reply_dirfrag *dir_dir;
  84                         size_t                        dir_buf_size;
  85                         int                           dir_nr;
  86                         bool                          dir_end;
  87                         bool                          dir_complete;
  88                         bool                          hash_order;
  89                         bool                          offset_hash;
  90                         struct ceph_mds_reply_dir_entry  *dir_entries;
  91                 };
  92
  93                 /* for create results */
  94                 struct {
  95                         bool has_create_ino;
  96                         u64 ino;
  97                 };
  98         };
  99
 100         /* encoded blob describing snapshot contexts for certain
 101            operations (e.g., open) */
 102         void *snapblob;
 103         int snapblob_len;
 104 };
 105
 106
 107 /*
 108  * cap releases are batched and sent to the MDS en masse.
 109  *
 110  * Account for per-message overhead of mds_cap_release header
 111  * and __le32 for osd epoch barrier trailing field.
 112  */
 113 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 114                                 sizeof(struct ceph_mds_cap_release)) /  \
 115                                 sizeof(struct ceph_mds_cap_item))
 116
 117
 118 /*
 119  * state associated with each MDS<->client session
 120  */
 121 enum {
 122         CEPH_MDS_SESSION_NEW = 1,
 123         CEPH_MDS_SESSION_OPENING = 2,
 124         CEPH_MDS_SESSION_OPEN = 3,
 125         CEPH_MDS_SESSION_HUNG = 4,
 126         CEPH_MDS_SESSION_CLOSING = 5,
 127         CEPH_MDS_SESSION_RESTARTING = 6,
 128         CEPH_MDS_SESSION_RECONNECTING = 7,
 129         CEPH_MDS_SESSION_REJECTED = 8,
 130 };
 131
 132 struct ceph_mds_session {
 133         struct ceph_mds_client *s_mdsc;
 134         int               s_mds;
 135         int               s_state;
 136         unsigned long     s_ttl;      /* time until mds kills us */
 137         u64               s_seq;      /* incoming msg seq # */
 138         struct mutex      s_mutex;    /* serialize session messages */
 139
 140         struct ceph_connection s_con;
 141
 142         struct ceph_auth_handshake s_auth;
 143
 144         /* protected by s_gen_ttl_lock */
 145         spinlock_t        s_gen_ttl_lock;
 146         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 147         unsigned long     s_cap_ttl;  /* when session caps expire */
 148
 149         /* protected by s_cap_lock */
 150         spinlock_t        s_cap_lock;
 151         struct list_head  s_caps;     /* all caps issued by this session */
 152         int               s_nr_caps, s_trim_caps;
 153         int               s_num_cap_releases;
 154         int               s_cap_reconnect;
 155         int               s_readonly;
 156         struct list_head  s_cap_releases; /* waiting cap_release messages */
 157         struct ceph_cap  *s_cap_iterator;
 158
 159         /* protected by mutex */
 160         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 161         unsigned long     s_renew_requested; /* last time we sent a renew req */
 162         u64               s_renew_seq;
 163
 164         refcount_t          s_ref;
 165         struct list_head  s_waiting;  /* waiting requests */
 166         struct list_head  s_unsafe;   /* unsafe requests */
 167 };
 168
 169 /*
 170  * modes of choosing which MDS to send a request to
 171  */
 172 enum {
 173         USE_ANY_MDS,
 174         USE_RANDOM_MDS,
 175         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 176 };
 177
 178 struct ceph_mds_request;
 179 struct ceph_mds_client;
 180
 181 /*
 182  * request completion callback
 183  */
 184 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 185                                              struct ceph_mds_request *req);
 186 /*
 187  * wait for request completion callback
 188  */
 189 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 190                                                  struct ceph_mds_request *req);
 191
 192 /*
 193  * an in-flight mds request
 194  */
 195 struct ceph_mds_request {
 196         u64 r_tid;                   /* transaction id */
 197         struct rb_node r_node;
 198         struct ceph_mds_client *r_mdsc;
 199
 200         int r_op;                    /* mds op code */
 201
 202         /* operation on what? */
 203         struct inode *r_inode;              /* arg1 */
 204         struct dentry *r_dentry;            /* arg1 */
 205         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 206         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 207         char *r_path1, *r_path2;
 208         struct ceph_vino r_ino1, r_ino2;
 209
 210         struct inode *r_parent;             /* parent dir inode */
 211         struct inode *r_target_inode;       /* resulting inode */
 212
 213 #define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 214 #define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 215 #define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 216 #define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 217 #define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 218 #define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 219 #define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 220         unsigned long   r_req_flags;
 221
 222         struct mutex r_fill_mutex;
 223
 224         union ceph_mds_request_args r_args;
 225         int r_fmode;        /* file mode, if expecting cap */
 226         kuid_t r_uid;
 227         kgid_t r_gid;
 228         struct timespec r_stamp;
 229
 230         /* for choosing which mds to send this request to */
 231         int r_direct_mode;
 232         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 233
 234         /* data payload is used for xattr ops */
 235         struct ceph_pagelist *r_pagelist;
 236
 237         /* what caps shall we drop? */
 238         int r_inode_drop, r_inode_unless;
 239         int r_dentry_drop, r_dentry_unless;
 240         int r_old_dentry_drop, r_old_dentry_unless;
 241         struct inode *r_old_inode;
 242         int r_old_inode_drop, r_old_inode_unless;
 243
 244         struct ceph_msg  *r_request;  /* original request */
 245         int r_request_release_offset;
 246         struct ceph_msg  *r_reply;
 247         struct ceph_mds_reply_info_parsed r_reply_info;
 248         struct page *r_locked_page;
 249         int r_err;
 250
 251         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 252         unsigned long r_started;  /* start time to measure timeout against */
 253         unsigned long r_request_started; /* start time for mds request only,
 254                                             used to measure lease durations */
 255
 256         /* link unsafe requests to parent directory, for fsync */
 257         struct inode    *r_unsafe_dir;
 258         struct list_head r_unsafe_dir_item;
 259
 260         /* unsafe requests that modify the target inode */
 261         struct list_head r_unsafe_target_item;
 262
 263         struct ceph_mds_session *r_session;
 264
 265         int               r_attempts;   /* resend attempts */
 266         int               r_num_fwd;    /* number of forward attempts */
 267         int               r_resend_mds; /* mds to resend to next, if any*/
 268         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 269
 270         struct kref       r_kref;
 271         struct list_head  r_wait;
 272         struct completion r_completion;
 273         struct completion r_safe_completion;
 274         ceph_mds_request_callback_t r_callback;
 275         ceph_mds_request_wait_callback_t r_wait_for_completion;
 276         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 277
 278         long long         r_dir_release_cnt;
 279         long long         r_dir_ordered_cnt;
 280         int               r_readdir_cache_idx;
 281         u32               r_readdir_offset;
 282
 283         struct ceph_cap_reservation r_caps_reservation;
 284         int r_num_caps;
 285 };
 286
 287 struct ceph_pool_perm {
 288         struct rb_node node;
 289         int perm;
 290         s64 pool;
 291         size_t pool_ns_len;
 292         char pool_ns[];
 293 };
 294
 295 /*
 296  * mds client state
 297  */
 298 struct ceph_mds_client {
 299         struct ceph_fs_client  *fsc;
 300         struct mutex            mutex;         /* all nested structures */
 301
 302         struct ceph_mdsmap      *mdsmap;
 303         struct completion       safe_umount_waiters;
 304         wait_queue_head_t       session_close_wq;
 305         struct list_head        waiting_for_map;
 306         int                     mdsmap_err;
 307
 308         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 309         atomic_t                num_sessions;
 310         int                     max_sessions;  /* len of s_mds_sessions */
 311         int                     stopping;      /* true if shutting down */
 312
 313         /*
 314          * snap_rwsem will cover cap linkage into snaprealms, and
 315          * realm snap contexts.  (later, we can do per-realm snap
 316          * contexts locks..)  the empty list contains realms with no
 317          * references (implying they contain no inodes with caps) that
 318          * should be destroyed.
 319          */
 320         u64                     last_snap_seq;
 321         struct rw_semaphore     snap_rwsem;
 322         struct rb_root          snap_realms;
 323         struct list_head        snap_empty;
 324         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 325
 326         u64                    last_tid;      /* most recent mds request */
 327         u64                    oldest_tid;    /* oldest incomplete mds request,
 328                                                  excluding setfilelock requests */
 329         struct rb_root         request_tree;  /* pending mds requests */
 330         struct delayed_work    delayed_work;  /* delayed work */
 331         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 332         struct list_head cap_delay_list;   /* caps with delayed release */
 333         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 334         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 335         spinlock_t       snap_flush_lock;
 336
 337         u64               last_cap_flush_tid;
 338         struct list_head  cap_flush_list;
 339         struct list_head  cap_dirty;        /* inodes with dirty caps */
 340         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 341         int               num_cap_flushing; /* # caps we are flushing */
 342         spinlock_t        cap_dirty_lock;   /* protects above items */
 343         wait_queue_head_t cap_flushing_wq;
 344
 345         /*
 346          * Cap reservations
 347          *
 348          * Maintain a global pool of preallocated struct ceph_caps, referenced
 349          * by struct ceph_caps_reservations.  This ensures that we preallocate
 350          * memory needed to successfully process an MDS response.  (If an MDS
 351          * sends us cap information and we fail to process it, we will have
 352          * problems due to the client and MDS being out of sync.)
 353          *
 354          * Reservations are 'owned' by a ceph_cap_reservation context.
 355          */
 356         spinlock_t      caps_list_lock;
 357         struct          list_head caps_list; /* unused (reserved or
 358                                                 unreserved) */
 359         int             caps_total_count;    /* total caps allocated */
 360         int             caps_use_count;      /* in use */
 361         int             caps_reserve_count;  /* unused, reserved */
 362         int             caps_avail_count;    /* unused, unreserved */
 363         int             caps_min_count;      /* keep at least this many
 364                                                 (unreserved) */
 365         spinlock_t        dentry_lru_lock;
 366         struct list_head  dentry_lru;
 367         int               num_dentry;
 368
 369         struct rw_semaphore     pool_perm_rwsem;
 370         struct rb_root          pool_perm_tree;
 371 };
 372
 373 extern const char *ceph_mds_op_name(int op);
 374
 375 extern struct ceph_mds_session *
 376 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 377
 378 static inline struct ceph_mds_session *
 379 ceph_get_mds_session(struct ceph_mds_session *s)
 380 {
 381         refcount_inc(&s->s_ref);
 382         return s;
 383 }
 384
 385 extern const char *ceph_session_state_name(int s);
 386
 387 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 388
 389 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 390                              struct ceph_msg *msg, int mds);
 391
 392 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 393 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 394 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 395 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 396
 397 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 398
 399 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 400 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 401                                            struct inode *dir);
 402 extern struct ceph_mds_request *
 403 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 404 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 405                                      struct ceph_mds_request *req);
 406 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 407                                 struct inode *dir,
 408                                 struct ceph_mds_request *req);
 409 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 410 {
 411         kref_get(&req->r_kref);
 412 }
 413 extern void ceph_mdsc_release_request(struct kref *kref);
 414 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 415 {
 416         kref_put(&req->r_kref, ceph_mdsc_release_request);
 417 }
 418
 419 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 420                                    struct ceph_mds_session *session);
 421
 422 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 423
 424 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 425                                   int stop_on_nosnap);
 426
 427 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 428 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 429                                      struct inode *inode,
 430                                      struct dentry *dentry, char action,
 431                                      u32 seq);
 432
 433 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 434                                     struct ceph_msg *msg);
 435 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 436                                    struct ceph_msg *msg);
 437
 438 extern struct ceph_mds_session *
 439 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 440 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 441                                           struct ceph_mds_session *session);
 442
 443 #endif