LXR linux/fs/ceph/mds

   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
  31struct ceph_fs_client;
  32struct 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 */
  38struct 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
  52struct 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 */
  66struct 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 */
 121enum {
 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
 132struct 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 */
 172enum {
 173        USE_ANY_MDS,
 174        USE_RANDOM_MDS,
 175        USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 176};
 177
 178struct ceph_mds_request;
 179struct ceph_mds_client;
 180
 181/*
 182 * request completion callback
 183 */
 184typedef 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 */
 189typedef 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 */
 195struct 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
 287struct 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 */
 298struct 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
 373extern const char *ceph_mds_op_name(int op);
 374
 375extern struct ceph_mds_session *
 376__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 377
 378static inline struct ceph_mds_session *
 379ceph_get_mds_session(struct ceph_mds_session *s)
 380{
 381        refcount_inc(&s->s_ref);
 382        return s;
 383}
 384
 385extern const char *ceph_session_state_name(int s);
 386
 387extern void ceph_put_mds_session(struct ceph_mds_session *s);
 388
 389extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 390                             struct ceph_msg *msg, int mds);
 391
 392extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 393extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 394extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 395extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 396
 397extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 398
 399extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 400extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 401                                           struct inode *dir);
 402extern struct ceph_mds_request *
 403ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 404extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 405                                     struct ceph_mds_request *req);
 406extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 407                                struct inode *dir,
 408                                struct ceph_mds_request *req);
 409static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 410{
 411        kref_get(&req->r_kref);
 412}
 413extern void ceph_mdsc_release_request(struct kref *kref);
 414static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 415{
 416        kref_put(&req->r_kref, ceph_mdsc_release_request);
 417}
 418
 419extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 420                                   struct ceph_mds_session *session);
 421
 422extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 423
 424extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 425                                  int stop_on_nosnap);
 426
 427extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 428extern 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
 433extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 434                                    struct ceph_msg *msg);
 435extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 436                                   struct ceph_msg *msg);
 437
 438extern struct ceph_mds_session *
 439ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 440extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 441                                          struct ceph_mds_session *session);
 442
 443#endif
 444