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 #include <linux/utsname.h>
  12
  13 #include <linux/ceph/types.h>
  14 #include <linux/ceph/messenger.h>
  15 #include <linux/ceph/mdsmap.h>
  16 #include <linux/ceph/auth.h>
  17
  18 /*
  19  * Some lock dependencies:
  20  *
  21  * session->s_mutex
  22  *         mdsc->mutex
  23  *
  24  *         mdsc->snap_rwsem
  25  *
  26  *         ci->i_ceph_lock
  27  *                 mdsc->snap_flush_lock
  28  *                 mdsc->cap_delay_lock
  29  *
  30  */
  31
  32 struct ceph_fs_client;
  33 struct ceph_cap;
  34
  35 /*
  36  * parsed info about a single inode.  pointers are into the encoded
  37  * on-wire structures within the mds reply message payload.
  38  */
  39 struct ceph_mds_reply_info_in {
  40         struct ceph_mds_reply_inode *in;
  41         struct ceph_dir_layout dir_layout;
  42         u32 symlink_len;
  43         char *symlink;
  44         u32 xattr_len;
  45         char *xattr_data;
  46         u64 inline_version;
  47         u32 inline_len;
  48         char *inline_data;
  49         u32 pool_ns_len;
  50         char *pool_ns_data;
  51 };
  52
  53 struct ceph_mds_reply_dir_entry {
  54         char                          *name;
  55         u32                           name_len;
  56         struct ceph_mds_reply_lease   *lease;
  57         struct ceph_mds_reply_info_in inode;
  58         loff_t                        offset;
  59 };
  60
  61 /*
  62  * parsed info about an mds reply, including information about
  63  * either: 1) the target inode and/or its parent directory and dentry,
  64  * and directory contents (for readdir results), or
  65  * 2) the file range lock info (for fcntl F_GETLK results).
  66  */
  67 struct ceph_mds_reply_info_parsed {
  68         struct ceph_mds_reply_head    *head;
  69
  70         /* trace */
  71         struct ceph_mds_reply_info_in diri, targeti;
  72         struct ceph_mds_reply_dirfrag *dirfrag;
  73         char                          *dname;
  74         u32                           dname_len;
  75         struct ceph_mds_reply_lease   *dlease;
  76
  77         /* extra */
  78         union {
  79                 /* for fcntl F_GETLK results */
  80                 struct ceph_filelock *filelock_reply;
  81
  82                 /* for readdir results */
  83                 struct {
  84                         struct ceph_mds_reply_dirfrag *dir_dir;
  85                         size_t                        dir_buf_size;
  86                         int                           dir_nr;
  87                         bool                          dir_end;
  88                         bool                          dir_complete;
  89                         bool                          hash_order;
  90                         bool                          offset_hash;
  91                         struct ceph_mds_reply_dir_entry  *dir_entries;
  92                 };
  93
  94                 /* for create results */
  95                 struct {
  96                         bool has_create_ino;
  97                         u64 ino;
  98                 };
  99         };
 100
 101         /* encoded blob describing snapshot contexts for certain
 102            operations (e.g., open) */
 103         void *snapblob;
 104         int snapblob_len;
 105 };
 106
 107
 108 /*
 109  * cap releases are batched and sent to the MDS en masse.
 110  *
 111  * Account for per-message overhead of mds_cap_release header
 112  * and __le32 for osd epoch barrier trailing field.
 113  */
 114 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 115                                 sizeof(struct ceph_mds_cap_release)) /  \
 116                                 sizeof(struct ceph_mds_cap_item))
 117
 118
 119 /*
 120  * state associated with each MDS<->client session
 121  */
 122 enum {
 123         CEPH_MDS_SESSION_NEW = 1,
 124         CEPH_MDS_SESSION_OPENING = 2,
 125         CEPH_MDS_SESSION_OPEN = 3,
 126         CEPH_MDS_SESSION_HUNG = 4,
 127         CEPH_MDS_SESSION_CLOSING = 5,
 128         CEPH_MDS_SESSION_RESTARTING = 6,
 129         CEPH_MDS_SESSION_RECONNECTING = 7,
 130         CEPH_MDS_SESSION_REJECTED = 8,
 131 };
 132
 133 struct ceph_mds_session {
 134         struct ceph_mds_client *s_mdsc;
 135         int               s_mds;
 136         int               s_state;
 137         unsigned long     s_ttl;      /* time until mds kills us */
 138         u64               s_seq;      /* incoming msg seq # */
 139         struct mutex      s_mutex;    /* serialize session messages */
 140
 141         struct ceph_connection s_con;
 142
 143         struct ceph_auth_handshake s_auth;
 144
 145         /* protected by s_gen_ttl_lock */
 146         spinlock_t        s_gen_ttl_lock;
 147         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 148         unsigned long     s_cap_ttl;  /* when session caps expire */
 149
 150         /* protected by s_cap_lock */
 151         spinlock_t        s_cap_lock;
 152         struct list_head  s_caps;     /* all caps issued by this session */
 153         int               s_nr_caps, s_trim_caps;
 154         int               s_num_cap_releases;
 155         int               s_cap_reconnect;
 156         int               s_readonly;
 157         struct list_head  s_cap_releases; /* waiting cap_release messages */
 158         struct ceph_cap  *s_cap_iterator;
 159
 160         /* protected by mutex */
 161         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 162         unsigned long     s_renew_requested; /* last time we sent a renew req */
 163         u64               s_renew_seq;
 164
 165         refcount_t          s_ref;
 166         struct list_head  s_waiting;  /* waiting requests */
 167         struct list_head  s_unsafe;   /* unsafe requests */
 168 };
 169
 170 /*
 171  * modes of choosing which MDS to send a request to
 172  */
 173 enum {
 174         USE_ANY_MDS,
 175         USE_RANDOM_MDS,
 176         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 177 };
 178
 179 struct ceph_mds_request;
 180 struct ceph_mds_client;
 181
 182 /*
 183  * request completion callback
 184  */
 185 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 186                                              struct ceph_mds_request *req);
 187 /*
 188  * wait for request completion callback
 189  */
 190 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 191                                                  struct ceph_mds_request *req);
 192
 193 /*
 194  * an in-flight mds request
 195  */
 196 struct ceph_mds_request {
 197         u64 r_tid;                   /* transaction id */
 198         struct rb_node r_node;
 199         struct ceph_mds_client *r_mdsc;
 200
 201         int r_op;                    /* mds op code */
 202
 203         /* operation on what? */
 204         struct inode *r_inode;              /* arg1 */
 205         struct dentry *r_dentry;            /* arg1 */
 206         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 207         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 208         char *r_path1, *r_path2;
 209         struct ceph_vino r_ino1, r_ino2;
 210
 211         struct inode *r_parent;             /* parent dir inode */
 212         struct inode *r_target_inode;       /* resulting inode */
 213
 214 #define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 215 #define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 216 #define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 217 #define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 218 #define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 219 #define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 220 #define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 221         unsigned long   r_req_flags;
 222
 223         struct mutex r_fill_mutex;
 224
 225         union ceph_mds_request_args r_args;
 226         int r_fmode;        /* file mode, if expecting cap */
 227         kuid_t r_uid;
 228         kgid_t r_gid;
 229         struct timespec r_stamp;
 230
 231         /* for choosing which mds to send this request to */
 232         int r_direct_mode;
 233         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 234
 235         /* data payload is used for xattr ops */
 236         struct ceph_pagelist *r_pagelist;
 237
 238         /* what caps shall we drop? */
 239         int r_inode_drop, r_inode_unless;
 240         int r_dentry_drop, r_dentry_unless;
 241         int r_old_dentry_drop, r_old_dentry_unless;
 242         struct inode *r_old_inode;
 243         int r_old_inode_drop, r_old_inode_unless;
 244
 245         struct ceph_msg  *r_request;  /* original request */
 246         int r_request_release_offset;
 247         struct ceph_msg  *r_reply;
 248         struct ceph_mds_reply_info_parsed r_reply_info;
 249         struct page *r_locked_page;
 250         int r_err;
 251
 252         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 253         unsigned long r_started;  /* start time to measure timeout against */
 254         unsigned long r_request_started; /* start time for mds request only,
 255                                             used to measure lease durations */
 256
 257         /* link unsafe requests to parent directory, for fsync */
 258         struct inode    *r_unsafe_dir;
 259         struct list_head r_unsafe_dir_item;
 260
 261         /* unsafe requests that modify the target inode */
 262         struct list_head r_unsafe_target_item;
 263
 264         struct ceph_mds_session *r_session;
 265
 266         int               r_attempts;   /* resend attempts */
 267         int               r_num_fwd;    /* number of forward attempts */
 268         int               r_resend_mds; /* mds to resend to next, if any*/
 269         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 270
 271         struct kref       r_kref;
 272         struct list_head  r_wait;
 273         struct completion r_completion;
 274         struct completion r_safe_completion;
 275         ceph_mds_request_callback_t r_callback;
 276         ceph_mds_request_wait_callback_t r_wait_for_completion;
 277         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 278
 279         long long         r_dir_release_cnt;
 280         long long         r_dir_ordered_cnt;
 281         int               r_readdir_cache_idx;
 282         u32               r_readdir_offset;
 283
 284         struct ceph_cap_reservation r_caps_reservation;
 285         int r_num_caps;
 286 };
 287
 288 struct ceph_pool_perm {
 289         struct rb_node node;
 290         int perm;
 291         s64 pool;
 292         size_t pool_ns_len;
 293         char pool_ns[];
 294 };
 295
 296 /*
 297  * mds client state
 298  */
 299 struct ceph_mds_client {
 300         struct ceph_fs_client  *fsc;
 301         struct mutex            mutex;         /* all nested structures */
 302
 303         struct ceph_mdsmap      *mdsmap;
 304         struct completion       safe_umount_waiters;
 305         wait_queue_head_t       session_close_wq;
 306         struct list_head        waiting_for_map;
 307         int                     mdsmap_err;
 308
 309         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 310         atomic_t                num_sessions;
 311         int                     max_sessions;  /* len of s_mds_sessions */
 312         int                     stopping;      /* true if shutting down */
 313
 314         /*
 315          * snap_rwsem will cover cap linkage into snaprealms, and
 316          * realm snap contexts.  (later, we can do per-realm snap
 317          * contexts locks..)  the empty list contains realms with no
 318          * references (implying they contain no inodes with caps) that
 319          * should be destroyed.
 320          */
 321         u64                     last_snap_seq;
 322         struct rw_semaphore     snap_rwsem;
 323         struct rb_root          snap_realms;
 324         struct list_head        snap_empty;
 325         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 326
 327         u64                    last_tid;      /* most recent mds request */
 328         u64                    oldest_tid;    /* oldest incomplete mds request,
 329                                                  excluding setfilelock requests */
 330         struct rb_root         request_tree;  /* pending mds requests */
 331         struct delayed_work    delayed_work;  /* delayed work */
 332         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 333         struct list_head cap_delay_list;   /* caps with delayed release */
 334         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 335         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 336         spinlock_t       snap_flush_lock;
 337
 338         u64               last_cap_flush_tid;
 339         struct list_head  cap_flush_list;
 340         struct list_head  cap_dirty;        /* inodes with dirty caps */
 341         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 342         int               num_cap_flushing; /* # caps we are flushing */
 343         spinlock_t        cap_dirty_lock;   /* protects above items */
 344         wait_queue_head_t cap_flushing_wq;
 345
 346         /*
 347          * Cap reservations
 348          *
 349          * Maintain a global pool of preallocated struct ceph_caps, referenced
 350          * by struct ceph_caps_reservations.  This ensures that we preallocate
 351          * memory needed to successfully process an MDS response.  (If an MDS
 352          * sends us cap information and we fail to process it, we will have
 353          * problems due to the client and MDS being out of sync.)
 354          *
 355          * Reservations are 'owned' by a ceph_cap_reservation context.
 356          */
 357         spinlock_t      caps_list_lock;
 358         struct          list_head caps_list; /* unused (reserved or
 359                                                 unreserved) */
 360         int             caps_total_count;    /* total caps allocated */
 361         int             caps_use_count;      /* in use */
 362         int             caps_reserve_count;  /* unused, reserved */
 363         int             caps_avail_count;    /* unused, unreserved */
 364         int             caps_min_count;      /* keep at least this many
 365                                                 (unreserved) */
 366         spinlock_t        dentry_lru_lock;
 367         struct list_head  dentry_lru;
 368         int               num_dentry;
 369
 370         struct rw_semaphore     pool_perm_rwsem;
 371         struct rb_root          pool_perm_tree;
 372
 373         char nodename[__NEW_UTS_LEN + 1];
 374 };
 375
 376 extern const char *ceph_mds_op_name(int op);
 377
 378 extern struct ceph_mds_session *
 379 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 380
 381 static inline struct ceph_mds_session *
 382 ceph_get_mds_session(struct ceph_mds_session *s)
 383 {
 384         refcount_inc(&s->s_ref);
 385         return s;
 386 }
 387
 388 extern const char *ceph_session_state_name(int s);
 389
 390 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 391
 392 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 393                              struct ceph_msg *msg, int mds);
 394
 395 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 396 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 397 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 398 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 399
 400 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 401
 402 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 403 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 404                                            struct inode *dir);
 405 extern struct ceph_mds_request *
 406 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 407 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 408                                      struct ceph_mds_request *req);
 409 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 410                                 struct inode *dir,
 411                                 struct ceph_mds_request *req);
 412 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 413 {
 414         kref_get(&req->r_kref);
 415 }
 416 extern void ceph_mdsc_release_request(struct kref *kref);
 417 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 418 {
 419         kref_put(&req->r_kref, ceph_mdsc_release_request);
 420 }
 421
 422 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 423                                    struct ceph_mds_session *session);
 424
 425 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 426
 427 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 428                                   int stop_on_nosnap);
 429
 430 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 431 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 432                                      struct inode *inode,
 433                                      struct dentry *dentry, char action,
 434                                      u32 seq);
 435
 436 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 437                                     struct ceph_msg *msg);
 438 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 439                                    struct ceph_msg *msg);
 440
 441 extern struct ceph_mds_session *
 442 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 443 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 444                                           struct ceph_mds_session *session);
 445
 446 #endif