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