LXR linux/fs/ceph/mds

   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/* The first 8 bits are reserved for old ceph releases */
  20#define CEPHFS_FEATURE_MIMIC    8
  21
  22#define CEPHFS_FEATURES_ALL {           \
  23  0, 1, 2, 3, 4, 5, 6, 7,               \
  24  CEPHFS_FEATURE_MIMIC,                 \
  25}
  26
  27#define CEPHFS_FEATURES_CLIENT_SUPPORTED CEPHFS_FEATURES_ALL
  28#define CEPHFS_FEATURES_CLIENT_REQUIRED {}
  29
  30
  31/*
  32 * Some lock dependencies:
  33 *
  34 * session->s_mutex
  35 *         mdsc->mutex
  36 *
  37 *         mdsc->snap_rwsem
  38 *
  39 *         ci->i_ceph_lock
  40 *                 mdsc->snap_flush_lock
  41 *                 mdsc->cap_delay_lock
  42 *
  43 */
  44
  45struct ceph_fs_client;
  46struct ceph_cap;
  47
  48/*
  49 * parsed info about a single inode.  pointers are into the encoded
  50 * on-wire structures within the mds reply message payload.
  51 */
  52struct ceph_mds_reply_info_in {
  53        struct ceph_mds_reply_inode *in;
  54        struct ceph_dir_layout dir_layout;
  55        u32 symlink_len;
  56        char *symlink;
  57        u32 xattr_len;
  58        char *xattr_data;
  59        u64 inline_version;
  60        u32 inline_len;
  61        char *inline_data;
  62        u32 pool_ns_len;
  63        char *pool_ns_data;
  64        u64 max_bytes;
  65        u64 max_files;
  66};
  67
  68struct ceph_mds_reply_dir_entry {
  69        char                          *name;
  70        u32                           name_len;
  71        struct ceph_mds_reply_lease   *lease;
  72        struct ceph_mds_reply_info_in inode;
  73        loff_t                        offset;
  74};
  75
  76/*
  77 * parsed info about an mds reply, including information about
  78 * either: 1) the target inode and/or its parent directory and dentry,
  79 * and directory contents (for readdir results), or
  80 * 2) the file range lock info (for fcntl F_GETLK results).
  81 */
  82struct ceph_mds_reply_info_parsed {
  83        struct ceph_mds_reply_head    *head;
  84
  85        /* trace */
  86        struct ceph_mds_reply_info_in diri, targeti;
  87        struct ceph_mds_reply_dirfrag *dirfrag;
  88        char                          *dname;
  89        u32                           dname_len;
  90        struct ceph_mds_reply_lease   *dlease;
  91
  92        /* extra */
  93        union {
  94                /* for fcntl F_GETLK results */
  95                struct ceph_filelock *filelock_reply;
  96
  97                /* for readdir results */
  98                struct {
  99                        struct ceph_mds_reply_dirfrag *dir_dir;
 100                        size_t                        dir_buf_size;
 101                        int                           dir_nr;
 102                        bool                          dir_end;
 103                        bool                          dir_complete;
 104                        bool                          hash_order;
 105                        bool                          offset_hash;
 106                        struct ceph_mds_reply_dir_entry  *dir_entries;
 107                };
 108
 109                /* for create results */
 110                struct {
 111                        bool has_create_ino;
 112                        u64 ino;
 113                };
 114        };
 115
 116        /* encoded blob describing snapshot contexts for certain
 117           operations (e.g., open) */
 118        void *snapblob;
 119        int snapblob_len;
 120};
 121
 122
 123/*
 124 * cap releases are batched and sent to the MDS en masse.
 125 *
 126 * Account for per-message overhead of mds_cap_release header
 127 * and __le32 for osd epoch barrier trailing field.
 128 */
 129#define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 130                                sizeof(struct ceph_mds_cap_release)) /  \
 131                                sizeof(struct ceph_mds_cap_item))
 132
 133
 134/*
 135 * state associated with each MDS<->client session
 136 */
 137enum {
 138        CEPH_MDS_SESSION_NEW = 1,
 139        CEPH_MDS_SESSION_OPENING = 2,
 140        CEPH_MDS_SESSION_OPEN = 3,
 141        CEPH_MDS_SESSION_HUNG = 4,
 142        CEPH_MDS_SESSION_CLOSING = 5,
 143        CEPH_MDS_SESSION_RESTARTING = 6,
 144        CEPH_MDS_SESSION_RECONNECTING = 7,
 145        CEPH_MDS_SESSION_REJECTED = 8,
 146};
 147
 148struct ceph_mds_session {
 149        struct ceph_mds_client *s_mdsc;
 150        int               s_mds;
 151        int               s_state;
 152        unsigned long     s_ttl;      /* time until mds kills us */
 153        u64               s_seq;      /* incoming msg seq # */
 154        struct mutex      s_mutex;    /* serialize session messages */
 155
 156        struct ceph_connection s_con;
 157
 158        struct ceph_auth_handshake s_auth;
 159
 160        /* protected by s_gen_ttl_lock */
 161        spinlock_t        s_gen_ttl_lock;
 162        u32               s_cap_gen;  /* inc each time we get mds stale msg */
 163        unsigned long     s_cap_ttl;  /* when session caps expire */
 164
 165        /* protected by s_cap_lock */
 166        spinlock_t        s_cap_lock;
 167        struct list_head  s_caps;     /* all caps issued by this session */
 168        int               s_nr_caps, s_trim_caps;
 169        int               s_num_cap_releases;
 170        int               s_cap_reconnect;
 171        int               s_readonly;
 172        struct list_head  s_cap_releases; /* waiting cap_release messages */
 173        struct ceph_cap  *s_cap_iterator;
 174
 175        /* protected by mutex */
 176        struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 177        unsigned long     s_renew_requested; /* last time we sent a renew req */
 178        u64               s_renew_seq;
 179
 180        refcount_t          s_ref;
 181        struct list_head  s_waiting;  /* waiting requests */
 182        struct list_head  s_unsafe;   /* unsafe requests */
 183};
 184
 185/*
 186 * modes of choosing which MDS to send a request to
 187 */
 188enum {
 189        USE_ANY_MDS,
 190        USE_RANDOM_MDS,
 191        USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 192};
 193
 194struct ceph_mds_request;
 195struct ceph_mds_client;
 196
 197/*
 198 * request completion callback
 199 */
 200typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 201                                             struct ceph_mds_request *req);
 202/*
 203 * wait for request completion callback
 204 */
 205typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 206                                                 struct ceph_mds_request *req);
 207
 208/*
 209 * an in-flight mds request
 210 */
 211struct ceph_mds_request {
 212        u64 r_tid;                   /* transaction id */
 213        struct rb_node r_node;
 214        struct ceph_mds_client *r_mdsc;
 215
 216        int r_op;                    /* mds op code */
 217
 218        /* operation on what? */
 219        struct inode *r_inode;              /* arg1 */
 220        struct dentry *r_dentry;            /* arg1 */
 221        struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 222        struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 223        char *r_path1, *r_path2;
 224        struct ceph_vino r_ino1, r_ino2;
 225
 226        struct inode *r_parent;             /* parent dir inode */
 227        struct inode *r_target_inode;       /* resulting inode */
 228
 229#define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 230#define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 231#define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 232#define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 233#define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 234#define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 235#define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 236        unsigned long   r_req_flags;
 237
 238        struct mutex r_fill_mutex;
 239
 240        union ceph_mds_request_args r_args;
 241        int r_fmode;        /* file mode, if expecting cap */
 242        kuid_t r_uid;
 243        kgid_t r_gid;
 244        struct timespec64 r_stamp;
 245
 246        /* for choosing which mds to send this request to */
 247        int r_direct_mode;
 248        u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 249
 250        /* data payload is used for xattr ops */
 251        struct ceph_pagelist *r_pagelist;
 252
 253        /* what caps shall we drop? */
 254        int r_inode_drop, r_inode_unless;
 255        int r_dentry_drop, r_dentry_unless;
 256        int r_old_dentry_drop, r_old_dentry_unless;
 257        struct inode *r_old_inode;
 258        int r_old_inode_drop, r_old_inode_unless;
 259
 260        struct ceph_msg  *r_request;  /* original request */
 261        int r_request_release_offset;
 262        struct ceph_msg  *r_reply;
 263        struct ceph_mds_reply_info_parsed r_reply_info;
 264        struct page *r_locked_page;
 265        int r_err;
 266
 267        unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 268        unsigned long r_started;  /* start time to measure timeout against */
 269        unsigned long r_request_started; /* start time for mds request only,
 270                                            used to measure lease durations */
 271
 272        /* link unsafe requests to parent directory, for fsync */
 273        struct inode    *r_unsafe_dir;
 274        struct list_head r_unsafe_dir_item;
 275
 276        /* unsafe requests that modify the target inode */
 277        struct list_head r_unsafe_target_item;
 278
 279        struct ceph_mds_session *r_session;
 280
 281        int               r_attempts;   /* resend attempts */
 282        int               r_num_fwd;    /* number of forward attempts */
 283        int               r_resend_mds; /* mds to resend to next, if any*/
 284        u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 285
 286        struct kref       r_kref;
 287        struct list_head  r_wait;
 288        struct completion r_completion;
 289        struct completion r_safe_completion;
 290        ceph_mds_request_callback_t r_callback;
 291        ceph_mds_request_wait_callback_t r_wait_for_completion;
 292        struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 293
 294        long long         r_dir_release_cnt;
 295        long long         r_dir_ordered_cnt;
 296        int               r_readdir_cache_idx;
 297        u32               r_readdir_offset;
 298
 299        struct ceph_cap_reservation r_caps_reservation;
 300        int r_num_caps;
 301};
 302
 303struct ceph_pool_perm {
 304        struct rb_node node;
 305        int perm;
 306        s64 pool;
 307        size_t pool_ns_len;
 308        char pool_ns[];
 309};
 310
 311/*
 312 * mds client state
 313 */
 314struct ceph_mds_client {
 315        struct ceph_fs_client  *fsc;
 316        struct mutex            mutex;         /* all nested structures */
 317
 318        struct ceph_mdsmap      *mdsmap;
 319        struct completion       safe_umount_waiters;
 320        wait_queue_head_t       session_close_wq;
 321        struct list_head        waiting_for_map;
 322        int                     mdsmap_err;
 323
 324        struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 325        atomic_t                num_sessions;
 326        int                     max_sessions;  /* len of s_mds_sessions */
 327        int                     stopping;      /* true if shutting down */
 328
 329        atomic64_t              quotarealms_count; /* # realms with quota */
 330
 331        /*
 332         * snap_rwsem will cover cap linkage into snaprealms, and
 333         * realm snap contexts.  (later, we can do per-realm snap
 334         * contexts locks..)  the empty list contains realms with no
 335         * references (implying they contain no inodes with caps) that
 336         * should be destroyed.
 337         */
 338        u64                     last_snap_seq;
 339        struct rw_semaphore     snap_rwsem;
 340        struct rb_root          snap_realms;
 341        struct list_head        snap_empty;
 342        spinlock_t              snap_empty_lock;  /* protect snap_empty */
 343
 344        u64                    last_tid;      /* most recent mds request */
 345        u64                    oldest_tid;    /* oldest incomplete mds request,
 346                                                 excluding setfilelock requests */
 347        struct rb_root         request_tree;  /* pending mds requests */
 348        struct delayed_work    delayed_work;  /* delayed work */
 349        unsigned long    last_renew_caps;  /* last time we renewed our caps */
 350        struct list_head cap_delay_list;   /* caps with delayed release */
 351        spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 352        struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 353        spinlock_t       snap_flush_lock;
 354
 355        u64               last_cap_flush_tid;
 356        struct list_head  cap_flush_list;
 357        struct list_head  cap_dirty;        /* inodes with dirty caps */
 358        struct list_head  cap_dirty_migrating; /* ...that are migration... */
 359        int               num_cap_flushing; /* # caps we are flushing */
 360        spinlock_t        cap_dirty_lock;   /* protects above items */
 361        wait_queue_head_t cap_flushing_wq;
 362
 363        /*
 364         * Cap reservations
 365         *
 366         * Maintain a global pool of preallocated struct ceph_caps, referenced
 367         * by struct ceph_caps_reservations.  This ensures that we preallocate
 368         * memory needed to successfully process an MDS response.  (If an MDS
 369         * sends us cap information and we fail to process it, we will have
 370         * problems due to the client and MDS being out of sync.)
 371         *
 372         * Reservations are 'owned' by a ceph_cap_reservation context.
 373         */
 374        spinlock_t      caps_list_lock;
 375        struct          list_head caps_list; /* unused (reserved or
 376                                                unreserved) */
 377        int             caps_total_count;    /* total caps allocated */
 378        int             caps_use_count;      /* in use */
 379        int             caps_reserve_count;  /* unused, reserved */
 380        int             caps_avail_count;    /* unused, unreserved */
 381        int             caps_min_count;      /* keep at least this many
 382                                                (unreserved) */
 383        spinlock_t        dentry_lru_lock;
 384        struct list_head  dentry_lru;
 385        int               num_dentry;
 386
 387        struct rw_semaphore     pool_perm_rwsem;
 388        struct rb_root          pool_perm_tree;
 389
 390        char nodename[__NEW_UTS_LEN + 1];
 391};
 392
 393extern const char *ceph_mds_op_name(int op);
 394
 395extern struct ceph_mds_session *
 396__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 397
 398static inline struct ceph_mds_session *
 399ceph_get_mds_session(struct ceph_mds_session *s)
 400{
 401        refcount_inc(&s->s_ref);
 402        return s;
 403}
 404
 405extern const char *ceph_session_state_name(int s);
 406
 407extern void ceph_put_mds_session(struct ceph_mds_session *s);
 408
 409extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 410                             struct ceph_msg *msg, int mds);
 411
 412extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 413extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 414extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 415extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 416
 417extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 418
 419extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 420extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 421                                           struct inode *dir);
 422extern struct ceph_mds_request *
 423ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 424extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 425                                     struct ceph_mds_request *req);
 426extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 427                                struct inode *dir,
 428                                struct ceph_mds_request *req);
 429static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 430{
 431        kref_get(&req->r_kref);
 432}
 433extern void ceph_mdsc_release_request(struct kref *kref);
 434static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 435{
 436        kref_put(&req->r_kref, ceph_mdsc_release_request);
 437}
 438
 439extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 440                                   struct ceph_mds_session *session);
 441
 442extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 443
 444extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 445                                  int stop_on_nosnap);
 446
 447extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 448extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 449                                     struct inode *inode,
 450                                     struct dentry *dentry, char action,
 451                                     u32 seq);
 452
 453extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 454                                    struct ceph_msg *msg);
 455extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 456                                   struct ceph_msg *msg);
 457
 458extern struct ceph_mds_session *
 459ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 460extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 461                                          struct ceph_mds_session *session);
 462
 463extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
 464                          struct ceph_mds_session *session,
 465                          int max_caps);
 466#endif
 467