fs/ceph/mds_client.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _FS_CEPH_MDS_CLIENT_H
   3 #define _FS_CEPH_MDS_CLIENT_H
   4
   5 #include <linux/completion.h>
   6 #include <linux/kref.h>
   7 #include <linux/list.h>
   8 #include <linux/mutex.h>
   9 #include <linux/rbtree.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/refcount.h>
  12 #include <linux/utsname.h>
  13
  14 #include <linux/ceph/types.h>
  15 #include <linux/ceph/messenger.h>
  16 #include <linux/ceph/mdsmap.h>
  17 #include <linux/ceph/auth.h>
  18
  19 /*
  20  * Some lock dependencies:
  21  *
  22  * session->s_mutex
  23  *         mdsc->mutex
  24  *
  25  *         mdsc->snap_rwsem
  26  *
  27  *         ci->i_ceph_lock
  28  *                 mdsc->snap_flush_lock
  29  *                 mdsc->cap_delay_lock
  30  *
  31  */
  32
  33 struct ceph_fs_client;
  34 struct ceph_cap;
  35
  36 /*
  37  * parsed info about a single inode.  pointers are into the encoded
  38  * on-wire structures within the mds reply message payload.
  39  */
  40 struct ceph_mds_reply_info_in {
  41         struct ceph_mds_reply_inode *in;
  42         struct ceph_dir_layout dir_layout;
  43         u32 symlink_len;
  44         char *symlink;
  45         u32 xattr_len;
  46         char *xattr_data;
  47         u64 inline_version;
  48         u32 inline_len;
  49         char *inline_data;
  50         u32 pool_ns_len;
  51         char *pool_ns_data;
  52 };
  53
  54 struct ceph_mds_reply_dir_entry {
  55         char                          *name;
  56         u32                           name_len;
  57         struct ceph_mds_reply_lease   *lease;
  58         struct ceph_mds_reply_info_in inode;
  59         loff_t                        offset;
  60 };
  61
  62 /*
  63  * parsed info about an mds reply, including information about
  64  * either: 1) the target inode and/or its parent directory and dentry,
  65  * and directory contents (for readdir results), or
  66  * 2) the file range lock info (for fcntl F_GETLK results).
  67  */
  68 struct ceph_mds_reply_info_parsed {
  69         struct ceph_mds_reply_head    *head;
  70
  71         /* trace */
  72         struct ceph_mds_reply_info_in diri, targeti;
  73         struct ceph_mds_reply_dirfrag *dirfrag;
  74         char                          *dname;
  75         u32                           dname_len;
  76         struct ceph_mds_reply_lease   *dlease;
  77
  78         /* extra */
  79         union {
  80                 /* for fcntl F_GETLK results */
  81                 struct ceph_filelock *filelock_reply;
  82
  83                 /* for readdir results */
  84                 struct {
  85                         struct ceph_mds_reply_dirfrag *dir_dir;
  86                         size_t                        dir_buf_size;
  87                         int                           dir_nr;
  88                         bool                          dir_end;
  89                         bool                          dir_complete;
  90                         bool                          hash_order;
  91                         bool                          offset_hash;
  92                         struct ceph_mds_reply_dir_entry  *dir_entries;
  93                 };
  94
  95                 /* for create results */
  96                 struct {
  97                         bool has_create_ino;
  98                         u64 ino;
  99                 };
 100         };
 101
 102         /* encoded blob describing snapshot contexts for certain
 103            operations (e.g., open) */
 104         void *snapblob;
 105         int snapblob_len;
 106 };
 107
 108
 109 /*
 110  * cap releases are batched and sent to the MDS en masse.
 111  *
 112  * Account for per-message overhead of mds_cap_release header
 113  * and __le32 for osd epoch barrier trailing field.
 114  */
 115 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 116                                 sizeof(struct ceph_mds_cap_release)) /  \
 117                                 sizeof(struct ceph_mds_cap_item))
 118
 119
 120 /*
 121  * state associated with each MDS<->client session
 122  */
 123 enum {
 124         CEPH_MDS_SESSION_NEW = 1,
 125         CEPH_MDS_SESSION_OPENING = 2,
 126         CEPH_MDS_SESSION_OPEN = 3,
 127         CEPH_MDS_SESSION_HUNG = 4,
 128         CEPH_MDS_SESSION_CLOSING = 5,
 129         CEPH_MDS_SESSION_RESTARTING = 6,
 130         CEPH_MDS_SESSION_RECONNECTING = 7,
 131         CEPH_MDS_SESSION_REJECTED = 8,
 132 };
 133
 134 struct ceph_mds_session {
 135         struct ceph_mds_client *s_mdsc;
 136         int               s_mds;
 137         int               s_state;
 138         unsigned long     s_ttl;      /* time until mds kills us */
 139         u64               s_seq;      /* incoming msg seq # */
 140         struct mutex      s_mutex;    /* serialize session messages */
 141
 142         struct ceph_connection s_con;
 143
 144         struct ceph_auth_handshake s_auth;
 145
 146         /* protected by s_gen_ttl_lock */
 147         spinlock_t        s_gen_ttl_lock;
 148         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 149         unsigned long     s_cap_ttl;  /* when session caps expire */
 150
 151         /* protected by s_cap_lock */
 152         spinlock_t        s_cap_lock;
 153         struct list_head  s_caps;     /* all caps issued by this session */
 154         int               s_nr_caps, s_trim_caps;
 155         int               s_num_cap_releases;
 156         int               s_cap_reconnect;
 157         int               s_readonly;
 158         struct list_head  s_cap_releases; /* waiting cap_release messages */
 159         struct ceph_cap  *s_cap_iterator;
 160
 161         /* protected by mutex */
 162         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 163         unsigned long     s_renew_requested; /* last time we sent a renew req */
 164         u64               s_renew_seq;
 165
 166         refcount_t          s_ref;
 167         struct list_head  s_waiting;  /* waiting requests */
 168         struct list_head  s_unsafe;   /* unsafe requests */
 169 };
 170
 171 /*
 172  * modes of choosing which MDS to send a request to
 173  */
 174 enum {
 175         USE_ANY_MDS,
 176         USE_RANDOM_MDS,
 177         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 178 };
 179
 180 struct ceph_mds_request;
 181 struct ceph_mds_client;
 182
 183 /*
 184  * request completion callback
 185  */
 186 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 187                                              struct ceph_mds_request *req);
 188 /*
 189  * wait for request completion callback
 190  */
 191 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 192                                                  struct ceph_mds_request *req);
 193
 194 /*
 195  * an in-flight mds request
 196  */
 197 struct ceph_mds_request {
 198         u64 r_tid;                   /* transaction id */
 199         struct rb_node r_node;
 200         struct ceph_mds_client *r_mdsc;
 201
 202         int r_op;                    /* mds op code */
 203
 204         /* operation on what? */
 205         struct inode *r_inode;              /* arg1 */
 206         struct dentry *r_dentry;            /* arg1 */
 207         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 208         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 209         char *r_path1, *r_path2;
 210         struct ceph_vino r_ino1, r_ino2;
 211
 212         struct inode *r_parent;             /* parent dir inode */
 213         struct inode *r_target_inode;       /* resulting inode */
 214
 215 #define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 216 #define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 217 #define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 218 #define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 219 #define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 220 #define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 221 #define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 222         unsigned long   r_req_flags;
 223
 224         struct mutex r_fill_mutex;
 225
 226         union ceph_mds_request_args r_args;
 227         int r_fmode;        /* file mode, if expecting cap */
 228         kuid_t r_uid;
 229         kgid_t r_gid;
 230         struct timespec r_stamp;
 231
 232         /* for choosing which mds to send this request to */
 233         int r_direct_mode;
 234         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 235
 236         /* data payload is used for xattr ops */
 237         struct ceph_pagelist *r_pagelist;
 238
 239         /* what caps shall we drop? */
 240         int r_inode_drop, r_inode_unless;
 241         int r_dentry_drop, r_dentry_unless;
 242         int r_old_dentry_drop, r_old_dentry_unless;
 243         struct inode *r_old_inode;
 244         int r_old_inode_drop, r_old_inode_unless;
 245
 246         struct ceph_msg  *r_request;  /* original request */
 247         int r_request_release_offset;
 248         struct ceph_msg  *r_reply;
 249         struct ceph_mds_reply_info_parsed r_reply_info;
 250         struct page *r_locked_page;
 251         int r_err;
 252
 253         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 254         unsigned long r_started;  /* start time to measure timeout against */
 255         unsigned long r_request_started; /* start time for mds request only,
 256                                             used to measure lease durations */
 257
 258         /* link unsafe requests to parent directory, for fsync */
 259         struct inode    *r_unsafe_dir;
 260         struct list_head r_unsafe_dir_item;
 261
 262         /* unsafe requests that modify the target inode */
 263         struct list_head r_unsafe_target_item;
 264
 265         struct ceph_mds_session *r_session;
 266
 267         int               r_attempts;   /* resend attempts */
 268         int               r_num_fwd;    /* number of forward attempts */
 269         int               r_resend_mds; /* mds to resend to next, if any*/
 270         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 271
 272         struct kref       r_kref;
 273         struct list_head  r_wait;
 274         struct completion r_completion;
 275         struct completion r_safe_completion;
 276         ceph_mds_request_callback_t r_callback;
 277         ceph_mds_request_wait_callback_t r_wait_for_completion;
 278         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 279
 280         long long         r_dir_release_cnt;
 281         long long         r_dir_ordered_cnt;
 282         int               r_readdir_cache_idx;
 283         u32               r_readdir_offset;
 284
 285         struct ceph_cap_reservation r_caps_reservation;
 286         int r_num_caps;
 287 };
 288
 289 struct ceph_pool_perm {
 290         struct rb_node node;
 291         int perm;
 292         s64 pool;
 293         size_t pool_ns_len;
 294         char pool_ns[];
 295 };
 296
 297 /*
 298  * mds client state
 299  */
 300 struct ceph_mds_client {
 301         struct ceph_fs_client  *fsc;
 302         struct mutex            mutex;         /* all nested structures */
 303
 304         struct ceph_mdsmap      *mdsmap;
 305         struct completion       safe_umount_waiters;
 306         wait_queue_head_t       session_close_wq;
 307         struct list_head        waiting_for_map;
 308         int                     mdsmap_err;
 309
 310         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 311         atomic_t                num_sessions;
 312         int                     max_sessions;  /* len of s_mds_sessions */
 313         int                     stopping;      /* true if shutting down */
 314
 315         /*
 316          * snap_rwsem will cover cap linkage into snaprealms, and
 317          * realm snap contexts.  (later, we can do per-realm snap
 318          * contexts locks..)  the empty list contains realms with no
 319          * references (implying they contain no inodes with caps) that
 320          * should be destroyed.
 321          */
 322         u64                     last_snap_seq;
 323         struct rw_semaphore     snap_rwsem;
 324         struct rb_root          snap_realms;
 325         struct list_head        snap_empty;
 326         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 327
 328         u64                    last_tid;      /* most recent mds request */
 329         u64                    oldest_tid;    /* oldest incomplete mds request,
 330                                                  excluding setfilelock requests */
 331         struct rb_root         request_tree;  /* pending mds requests */
 332         struct delayed_work    delayed_work;  /* delayed work */
 333         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 334         struct list_head cap_delay_list;   /* caps with delayed release */
 335         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 336         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 337         spinlock_t       snap_flush_lock;
 338
 339         u64               last_cap_flush_tid;
 340         struct list_head  cap_flush_list;
 341         struct list_head  cap_dirty;        /* inodes with dirty caps */
 342         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 343         int               num_cap_flushing; /* # caps we are flushing */
 344         spinlock_t        cap_dirty_lock;   /* protects above items */
 345         wait_queue_head_t cap_flushing_wq;
 346
 347         /*
 348          * Cap reservations
 349          *
 350          * Maintain a global pool of preallocated struct ceph_caps, referenced
 351          * by struct ceph_caps_reservations.  This ensures that we preallocate
 352          * memory needed to successfully process an MDS response.  (If an MDS
 353          * sends us cap information and we fail to process it, we will have
 354          * problems due to the client and MDS being out of sync.)
 355          *
 356          * Reservations are 'owned' by a ceph_cap_reservation context.
 357          */
 358         spinlock_t      caps_list_lock;
 359         struct          list_head caps_list; /* unused (reserved or
 360                                                 unreserved) */
 361         int             caps_total_count;    /* total caps allocated */
 362         int             caps_use_count;      /* in use */
 363         int             caps_reserve_count;  /* unused, reserved */
 364         int             caps_avail_count;    /* unused, unreserved */
 365         int             caps_min_count;      /* keep at least this many
 366                                                 (unreserved) */
 367         spinlock_t        dentry_lru_lock;
 368         struct list_head  dentry_lru;
 369         int               num_dentry;
 370
 371         struct rw_semaphore     pool_perm_rwsem;
 372         struct rb_root          pool_perm_tree;
 373
 374         char nodename[__NEW_UTS_LEN + 1];
 375 };
 376
 377 extern const char *ceph_mds_op_name(int op);
 378
 379 extern struct ceph_mds_session *
 380 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 381
 382 static inline struct ceph_mds_session *
 383 ceph_get_mds_session(struct ceph_mds_session *s)
 384 {
 385         refcount_inc(&s->s_ref);
 386         return s;
 387 }
 388
 389 extern const char *ceph_session_state_name(int s);
 390
 391 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 392
 393 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 394                              struct ceph_msg *msg, int mds);
 395
 396 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 397 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 398 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 399 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 400
 401 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 402
 403 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 404 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 405                                            struct inode *dir);
 406 extern struct ceph_mds_request *
 407 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 408 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 409                                      struct ceph_mds_request *req);
 410 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 411                                 struct inode *dir,
 412                                 struct ceph_mds_request *req);
 413 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 414 {
 415         kref_get(&req->r_kref);
 416 }
 417 extern void ceph_mdsc_release_request(struct kref *kref);
 418 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 419 {
 420         kref_put(&req->r_kref, ceph_mdsc_release_request);
 421 }
 422
 423 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 424                                    struct ceph_mds_session *session);
 425
 426 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 427
 428 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 429                                   int stop_on_nosnap);
 430
 431 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 432 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 433                                      struct inode *inode,
 434                                      struct dentry *dentry, char action,
 435                                      u32 seq);
 436
 437 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 438                                     struct ceph_msg *msg);
 439 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 440                                    struct ceph_msg *msg);
 441
 442 extern struct ceph_mds_session *
 443 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 444 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 445                                           struct ceph_mds_session *session);
 446
 447 extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
 448                           struct ceph_mds_session *session,
 449                           int max_caps);
 450 #endif