linux/fs/ceph/mds_client.h
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   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#include <linux/ktime.h>
  14
  15#include <linux/ceph/types.h>
  16#include <linux/ceph/messenger.h>
  17#include <linux/ceph/mdsmap.h>
  18#include <linux/ceph/auth.h>
  19
  20#include "metric.h"
  21#include "super.h"
  22
  23/* The first 8 bits are reserved for old ceph releases */
  24enum ceph_feature_type {
  25        CEPHFS_FEATURE_MIMIC = 8,
  26        CEPHFS_FEATURE_REPLY_ENCODING,
  27        CEPHFS_FEATURE_RECLAIM_CLIENT,
  28        CEPHFS_FEATURE_LAZY_CAP_WANTED,
  29        CEPHFS_FEATURE_MULTI_RECONNECT,
  30        CEPHFS_FEATURE_DELEG_INO,
  31        CEPHFS_FEATURE_METRIC_COLLECT,
  32
  33        CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_METRIC_COLLECT,
  34};
  35
  36/*
  37 * This will always have the highest feature bit value
  38 * as the last element of the array.
  39 */
  40#define CEPHFS_FEATURES_CLIENT_SUPPORTED {      \
  41        0, 1, 2, 3, 4, 5, 6, 7,                 \
  42        CEPHFS_FEATURE_MIMIC,                   \
  43        CEPHFS_FEATURE_REPLY_ENCODING,          \
  44        CEPHFS_FEATURE_LAZY_CAP_WANTED,         \
  45        CEPHFS_FEATURE_MULTI_RECONNECT,         \
  46        CEPHFS_FEATURE_DELEG_INO,               \
  47        CEPHFS_FEATURE_METRIC_COLLECT,          \
  48                                                \
  49        CEPHFS_FEATURE_MAX,                     \
  50}
  51#define CEPHFS_FEATURES_CLIENT_REQUIRED {}
  52
  53/*
  54 * Some lock dependencies:
  55 *
  56 * session->s_mutex
  57 *         mdsc->mutex
  58 *
  59 *         mdsc->snap_rwsem
  60 *
  61 *         ci->i_ceph_lock
  62 *                 mdsc->snap_flush_lock
  63 *                 mdsc->cap_delay_lock
  64 *
  65 */
  66
  67struct ceph_fs_client;
  68struct ceph_cap;
  69
  70/*
  71 * parsed info about a single inode.  pointers are into the encoded
  72 * on-wire structures within the mds reply message payload.
  73 */
  74struct ceph_mds_reply_info_in {
  75        struct ceph_mds_reply_inode *in;
  76        struct ceph_dir_layout dir_layout;
  77        u32 symlink_len;
  78        char *symlink;
  79        u32 xattr_len;
  80        char *xattr_data;
  81        u64 inline_version;
  82        u32 inline_len;
  83        char *inline_data;
  84        u32 pool_ns_len;
  85        char *pool_ns_data;
  86        u64 max_bytes;
  87        u64 max_files;
  88        s32 dir_pin;
  89        struct ceph_timespec btime;
  90        struct ceph_timespec snap_btime;
  91        u64 rsnaps;
  92        u64 change_attr;
  93};
  94
  95struct ceph_mds_reply_dir_entry {
  96        char                          *name;
  97        u32                           name_len;
  98        struct ceph_mds_reply_lease   *lease;
  99        struct ceph_mds_reply_info_in inode;
 100        loff_t                        offset;
 101};
 102
 103/*
 104 * parsed info about an mds reply, including information about
 105 * either: 1) the target inode and/or its parent directory and dentry,
 106 * and directory contents (for readdir results), or
 107 * 2) the file range lock info (for fcntl F_GETLK results).
 108 */
 109struct ceph_mds_reply_info_parsed {
 110        struct ceph_mds_reply_head    *head;
 111
 112        /* trace */
 113        struct ceph_mds_reply_info_in diri, targeti;
 114        struct ceph_mds_reply_dirfrag *dirfrag;
 115        char                          *dname;
 116        u32                           dname_len;
 117        struct ceph_mds_reply_lease   *dlease;
 118
 119        /* extra */
 120        union {
 121                /* for fcntl F_GETLK results */
 122                struct ceph_filelock *filelock_reply;
 123
 124                /* for readdir results */
 125                struct {
 126                        struct ceph_mds_reply_dirfrag *dir_dir;
 127                        size_t                        dir_buf_size;
 128                        int                           dir_nr;
 129                        bool                          dir_end;
 130                        bool                          dir_complete;
 131                        bool                          hash_order;
 132                        bool                          offset_hash;
 133                        struct ceph_mds_reply_dir_entry  *dir_entries;
 134                };
 135
 136                /* for create results */
 137                struct {
 138                        bool has_create_ino;
 139                        u64 ino;
 140                };
 141        };
 142
 143        /* encoded blob describing snapshot contexts for certain
 144           operations (e.g., open) */
 145        void *snapblob;
 146        int snapblob_len;
 147};
 148
 149
 150/*
 151 * cap releases are batched and sent to the MDS en masse.
 152 *
 153 * Account for per-message overhead of mds_cap_release header
 154 * and __le32 for osd epoch barrier trailing field.
 155 */
 156#define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 157                                sizeof(struct ceph_mds_cap_release)) /  \
 158                                sizeof(struct ceph_mds_cap_item))
 159
 160
 161/*
 162 * state associated with each MDS<->client session
 163 */
 164enum {
 165        CEPH_MDS_SESSION_NEW = 1,
 166        CEPH_MDS_SESSION_OPENING = 2,
 167        CEPH_MDS_SESSION_OPEN = 3,
 168        CEPH_MDS_SESSION_HUNG = 4,
 169        CEPH_MDS_SESSION_RESTARTING = 5,
 170        CEPH_MDS_SESSION_RECONNECTING = 6,
 171        CEPH_MDS_SESSION_CLOSING = 7,
 172        CEPH_MDS_SESSION_CLOSED = 8,
 173        CEPH_MDS_SESSION_REJECTED = 9,
 174};
 175
 176struct ceph_mds_session {
 177        struct ceph_mds_client *s_mdsc;
 178        int               s_mds;
 179        int               s_state;
 180        unsigned long     s_ttl;      /* time until mds kills us */
 181        unsigned long     s_features;
 182        u64               s_seq;      /* incoming msg seq # */
 183        struct mutex      s_mutex;    /* serialize session messages */
 184
 185        struct ceph_connection s_con;
 186
 187        struct ceph_auth_handshake s_auth;
 188
 189        atomic_t          s_cap_gen;  /* inc each time we get mds stale msg */
 190        unsigned long     s_cap_ttl;  /* when session caps expire. protected by s_mutex */
 191
 192        /* protected by s_cap_lock */
 193        spinlock_t        s_cap_lock;
 194        refcount_t        s_ref;
 195        struct list_head  s_caps;     /* all caps issued by this session */
 196        struct ceph_cap  *s_cap_iterator;
 197        int               s_nr_caps;
 198        int               s_num_cap_releases;
 199        int               s_cap_reconnect;
 200        int               s_readonly;
 201        struct list_head  s_cap_releases; /* waiting cap_release messages */
 202        struct work_struct s_cap_release_work;
 203
 204        /* See ceph_inode_info->i_dirty_item. */
 205        struct list_head  s_cap_dirty;        /* inodes w/ dirty caps */
 206
 207        /* See ceph_inode_info->i_flushing_item. */
 208        struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 209
 210        unsigned long     s_renew_requested; /* last time we sent a renew req */
 211        u64               s_renew_seq;
 212
 213        struct list_head  s_waiting;  /* waiting requests */
 214        struct list_head  s_unsafe;   /* unsafe requests */
 215        struct xarray     s_delegated_inos;
 216};
 217
 218/*
 219 * modes of choosing which MDS to send a request to
 220 */
 221enum {
 222        USE_ANY_MDS,
 223        USE_RANDOM_MDS,
 224        USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 225};
 226
 227struct ceph_mds_request;
 228struct ceph_mds_client;
 229
 230/*
 231 * request completion callback
 232 */
 233typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 234                                             struct ceph_mds_request *req);
 235/*
 236 * wait for request completion callback
 237 */
 238typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 239                                                 struct ceph_mds_request *req);
 240
 241/*
 242 * an in-flight mds request
 243 */
 244struct ceph_mds_request {
 245        u64 r_tid;                   /* transaction id */
 246        struct rb_node r_node;
 247        struct ceph_mds_client *r_mdsc;
 248
 249        struct kref       r_kref;
 250        int r_op;                    /* mds op code */
 251
 252        /* operation on what? */
 253        struct inode *r_inode;              /* arg1 */
 254        struct dentry *r_dentry;            /* arg1 */
 255        struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 256        struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 257        char *r_path1, *r_path2;
 258        struct ceph_vino r_ino1, r_ino2;
 259
 260        struct inode *r_parent;             /* parent dir inode */
 261        struct inode *r_target_inode;       /* resulting inode */
 262
 263#define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 264#define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 265#define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 266#define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 267#define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 268#define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 269#define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 270#define CEPH_MDS_R_ASYNC                (8) /* async request */
 271        unsigned long   r_req_flags;
 272
 273        struct mutex r_fill_mutex;
 274
 275        union ceph_mds_request_args r_args;
 276        int r_fmode;        /* file mode, if expecting cap */
 277        const struct cred *r_cred;
 278        int r_request_release_offset;
 279        struct timespec64 r_stamp;
 280
 281        /* for choosing which mds to send this request to */
 282        int r_direct_mode;
 283        u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 284
 285        /* data payload is used for xattr ops */
 286        struct ceph_pagelist *r_pagelist;
 287
 288        /* what caps shall we drop? */
 289        int r_inode_drop, r_inode_unless;
 290        int r_dentry_drop, r_dentry_unless;
 291        int r_old_dentry_drop, r_old_dentry_unless;
 292        struct inode *r_old_inode;
 293        int r_old_inode_drop, r_old_inode_unless;
 294
 295        struct ceph_msg  *r_request;  /* original request */
 296        struct ceph_msg  *r_reply;
 297        struct ceph_mds_reply_info_parsed r_reply_info;
 298        int r_err;
 299
 300
 301        struct page *r_locked_page;
 302        int r_dir_caps;
 303        int r_num_caps;
 304        u32               r_readdir_offset;
 305
 306        unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 307        unsigned long r_started;  /* start time to measure timeout against */
 308        unsigned long r_start_latency;  /* start time to measure latency */
 309        unsigned long r_end_latency;    /* finish time to measure latency */
 310        unsigned long r_request_started; /* start time for mds request only,
 311                                            used to measure lease durations */
 312
 313        /* link unsafe requests to parent directory, for fsync */
 314        struct inode    *r_unsafe_dir;
 315        struct list_head r_unsafe_dir_item;
 316
 317        /* unsafe requests that modify the target inode */
 318        struct list_head r_unsafe_target_item;
 319
 320        struct ceph_mds_session *r_session;
 321
 322        int               r_attempts;   /* resend attempts */
 323        int               r_num_fwd;    /* number of forward attempts */
 324        int               r_resend_mds; /* mds to resend to next, if any*/
 325        u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 326        u64               r_deleg_ino;
 327
 328        struct list_head  r_wait;
 329        struct completion r_completion;
 330        struct completion r_safe_completion;
 331        ceph_mds_request_callback_t r_callback;
 332        ceph_mds_request_wait_callback_t r_wait_for_completion;
 333        struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 334
 335        long long         r_dir_release_cnt;
 336        long long         r_dir_ordered_cnt;
 337        int               r_readdir_cache_idx;
 338
 339        struct ceph_cap_reservation r_caps_reservation;
 340};
 341
 342struct ceph_pool_perm {
 343        struct rb_node node;
 344        int perm;
 345        s64 pool;
 346        size_t pool_ns_len;
 347        char pool_ns[];
 348};
 349
 350struct ceph_snapid_map {
 351        struct rb_node node;
 352        struct list_head lru;
 353        atomic_t ref;
 354        u64 snap;
 355        dev_t dev;
 356        unsigned long last_used;
 357};
 358
 359/*
 360 * node for list of quotarealm inodes that are not visible from the filesystem
 361 * mountpoint, but required to handle, e.g. quotas.
 362 */
 363struct ceph_quotarealm_inode {
 364        struct rb_node node;
 365        u64 ino;
 366        unsigned long timeout; /* last time a lookup failed for this inode */
 367        struct mutex mutex;
 368        struct inode *inode;
 369};
 370
 371struct cap_wait {
 372        struct list_head        list;
 373        u64                     ino;
 374        pid_t                   tgid;
 375        int                     need;
 376        int                     want;
 377};
 378
 379/*
 380 * mds client state
 381 */
 382struct ceph_mds_client {
 383        struct ceph_fs_client  *fsc;
 384        struct mutex            mutex;         /* all nested structures */
 385
 386        struct ceph_mdsmap      *mdsmap;
 387        struct completion       safe_umount_waiters;
 388        wait_queue_head_t       session_close_wq;
 389        struct list_head        waiting_for_map;
 390        int                     mdsmap_err;
 391
 392        struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 393        atomic_t                num_sessions;
 394        int                     max_sessions;  /* len of sessions array */
 395        int                     stopping;      /* true if shutting down */
 396
 397        atomic64_t              quotarealms_count; /* # realms with quota */
 398        /*
 399         * We keep a list of inodes we don't see in the mountpoint but that we
 400         * need to track quota realms.
 401         */
 402        struct rb_root          quotarealms_inodes;
 403        struct mutex            quotarealms_inodes_mutex;
 404
 405        /*
 406         * snap_rwsem will cover cap linkage into snaprealms, and
 407         * realm snap contexts.  (later, we can do per-realm snap
 408         * contexts locks..)  the empty list contains realms with no
 409         * references (implying they contain no inodes with caps) that
 410         * should be destroyed.
 411         */
 412        u64                     last_snap_seq;
 413        struct rw_semaphore     snap_rwsem;
 414        struct rb_root          snap_realms;
 415        struct list_head        snap_empty;
 416        int                     num_snap_realms;
 417        spinlock_t              snap_empty_lock;  /* protect snap_empty */
 418
 419        u64                    last_tid;      /* most recent mds request */
 420        u64                    oldest_tid;    /* oldest incomplete mds request,
 421                                                 excluding setfilelock requests */
 422        struct rb_root         request_tree;  /* pending mds requests */
 423        struct delayed_work    delayed_work;  /* delayed work */
 424        unsigned long    last_renew_caps;  /* last time we renewed our caps */
 425        struct list_head cap_delay_list;   /* caps with delayed release */
 426        spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 427        struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 428        spinlock_t       snap_flush_lock;
 429
 430        u64               last_cap_flush_tid;
 431        struct list_head  cap_flush_list;
 432        struct list_head  cap_dirty_migrating; /* ...that are migration... */
 433        int               num_cap_flushing; /* # caps we are flushing */
 434        spinlock_t        cap_dirty_lock;   /* protects above items */
 435        wait_queue_head_t cap_flushing_wq;
 436
 437        struct work_struct cap_reclaim_work;
 438        atomic_t           cap_reclaim_pending;
 439
 440        /*
 441         * Cap reservations
 442         *
 443         * Maintain a global pool of preallocated struct ceph_caps, referenced
 444         * by struct ceph_caps_reservations.  This ensures that we preallocate
 445         * memory needed to successfully process an MDS response.  (If an MDS
 446         * sends us cap information and we fail to process it, we will have
 447         * problems due to the client and MDS being out of sync.)
 448         *
 449         * Reservations are 'owned' by a ceph_cap_reservation context.
 450         */
 451        spinlock_t      caps_list_lock;
 452        struct          list_head caps_list; /* unused (reserved or
 453                                                unreserved) */
 454        struct          list_head cap_wait_list;
 455        int             caps_total_count;    /* total caps allocated */
 456        int             caps_use_count;      /* in use */
 457        int             caps_use_max;        /* max used caps */
 458        int             caps_reserve_count;  /* unused, reserved */
 459        int             caps_avail_count;    /* unused, unreserved */
 460        int             caps_min_count;      /* keep at least this many
 461                                                (unreserved) */
 462        spinlock_t        dentry_list_lock;
 463        struct list_head  dentry_leases;     /* fifo list */
 464        struct list_head  dentry_dir_leases; /* lru list */
 465
 466        struct ceph_client_metric metric;
 467
 468        spinlock_t              snapid_map_lock;
 469        struct rb_root          snapid_map_tree;
 470        struct list_head        snapid_map_lru;
 471
 472        struct rw_semaphore     pool_perm_rwsem;
 473        struct rb_root          pool_perm_tree;
 474
 475        char nodename[__NEW_UTS_LEN + 1];
 476};
 477
 478extern const char *ceph_mds_op_name(int op);
 479
 480extern bool check_session_state(struct ceph_mds_session *s);
 481void inc_session_sequence(struct ceph_mds_session *s);
 482
 483extern struct ceph_mds_session *
 484__ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 485
 486extern const char *ceph_session_state_name(int s);
 487
 488extern struct ceph_mds_session *
 489ceph_get_mds_session(struct ceph_mds_session *s);
 490extern void ceph_put_mds_session(struct ceph_mds_session *s);
 491
 492extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 493                             struct ceph_msg *msg, int mds);
 494
 495extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 496extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 497extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 498extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 499
 500extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 501
 502extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 503extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 504                                           struct inode *dir);
 505extern struct ceph_mds_request *
 506ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 507extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 508                                    struct inode *dir,
 509                                    struct ceph_mds_request *req);
 510extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 511                                struct inode *dir,
 512                                struct ceph_mds_request *req);
 513extern void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req);
 514extern void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req);
 515static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 516{
 517        kref_get(&req->r_kref);
 518}
 519extern void ceph_mdsc_release_request(struct kref *kref);
 520static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 521{
 522        kref_put(&req->r_kref, ceph_mdsc_release_request);
 523}
 524
 525extern void __ceph_queue_cap_release(struct ceph_mds_session *session,
 526                                    struct ceph_cap *cap);
 527extern void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
 528                                    struct ceph_mds_session *session);
 529extern void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc);
 530extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
 531extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
 532                                     int (*cb)(struct inode *,
 533                                               struct ceph_cap *, void *),
 534                                     void *arg);
 535extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 536
 537static inline void ceph_mdsc_free_path(char *path, int len)
 538{
 539        if (!IS_ERR_OR_NULL(path))
 540                __putname(path - (PATH_MAX - 1 - len));
 541}
 542
 543extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 544                                  int stop_on_nosnap);
 545
 546extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 547extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 548                                     struct dentry *dentry, char action,
 549                                     u32 seq);
 550
 551extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 552                                    struct ceph_msg *msg);
 553extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 554                                   struct ceph_msg *msg);
 555
 556extern struct ceph_mds_session *
 557ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 558extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 559                                          struct ceph_mds_session *session);
 560
 561extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
 562                          struct ceph_mds_session *session,
 563                          int max_caps);
 564
 565static inline int ceph_wait_on_async_create(struct inode *inode)
 566{
 567        struct ceph_inode_info *ci = ceph_inode(inode);
 568
 569        return wait_on_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT,
 570                           TASK_INTERRUPTIBLE);
 571}
 572
 573extern u64 ceph_get_deleg_ino(struct ceph_mds_session *session);
 574extern int ceph_restore_deleg_ino(struct ceph_mds_session *session, u64 ino);
 575#endif
 576