fs/ceph/super.h

   1 #ifndef _FS_CEPH_SUPER_H
   2 #define _FS_CEPH_SUPER_H
   3
   4 #include "ceph_debug.h"
   5
   6 #include <asm/unaligned.h>
   7 #include <linux/backing-dev.h>
   8 #include <linux/completion.h>
   9 #include <linux/exportfs.h>
  10 #include <linux/fs.h>
  11 #include <linux/mempool.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/wait.h>
  14 #include <linux/writeback.h>
  15 #include <linux/slab.h>
  16
  17 #include "types.h"
  18 #include "messenger.h"
  19 #include "msgpool.h"
  20 #include "mon_client.h"
  21 #include "mds_client.h"
  22 #include "osd_client.h"
  23 #include "ceph_fs.h"
  24
  25 /* f_type in struct statfs */
  26 #define CEPH_SUPER_MAGIC 0x00c36400
  27
  28 /* large granularity for statfs utilization stats to facilitate
  29  * large volume sizes on 32-bit machines. */
  30 #define CEPH_BLOCK_SHIFT   20  /* 1 MB */
  31 #define CEPH_BLOCK         (1 << CEPH_BLOCK_SHIFT)
  32
  33 /*
  34  * Supported features
  35  */
  36 #define CEPH_FEATURE_SUPPORTED CEPH_FEATURE_NOSRCADDR | CEPH_FEATURE_FLOCK
  37 #define CEPH_FEATURE_REQUIRED  CEPH_FEATURE_NOSRCADDR
  38
  39 /*
  40  * mount options
  41  */
  42 #define CEPH_OPT_FSID             (1<<0)
  43 #define CEPH_OPT_NOSHARE          (1<<1) /* don't share client with other sbs */
  44 #define CEPH_OPT_MYIP             (1<<2) /* specified my ip */
  45 #define CEPH_OPT_DIRSTAT          (1<<4) /* funky `cat dirname` for stats */
  46 #define CEPH_OPT_RBYTES           (1<<5) /* dir st_bytes = rbytes */
  47 #define CEPH_OPT_NOCRC            (1<<6) /* no data crc on writes */
  48 #define CEPH_OPT_NOASYNCREADDIR   (1<<7) /* no dcache readdir */
  49
  50 #define CEPH_OPT_DEFAULT   (CEPH_OPT_RBYTES)
  51
  52 #define ceph_set_opt(client, opt) \
  53         (client)->mount_args->flags |= CEPH_OPT_##opt;
  54 #define ceph_test_opt(client, opt) \
  55         (!!((client)->mount_args->flags & CEPH_OPT_##opt))
  56
  57
  58 struct ceph_mount_args {
  59         int sb_flags;
  60         int flags;
  61         struct ceph_fsid fsid;
  62         struct ceph_entity_addr my_addr;
  63         int num_mon;
  64         struct ceph_entity_addr *mon_addr;
  65         int mount_timeout;
  66         int osd_idle_ttl;
  67         int osd_timeout;
  68         int osd_keepalive_timeout;
  69         int wsize;
  70         int rsize;            /* max readahead */
  71         int congestion_kb;    /* max writeback in flight */
  72         int caps_wanted_delay_min, caps_wanted_delay_max;
  73         int cap_release_safety;
  74         int max_readdir;       /* max readdir result (entires) */
  75         int max_readdir_bytes; /* max readdir result (bytes) */
  76         char *snapdir_name;   /* default ".snap" */
  77         char *name;
  78         char *secret;
  79 };
  80
  81 /*
  82  * defaults
  83  */
  84 #define CEPH_MOUNT_TIMEOUT_DEFAULT  60
  85 #define CEPH_OSD_TIMEOUT_DEFAULT    60  /* seconds */
  86 #define CEPH_OSD_KEEPALIVE_DEFAULT  5
  87 #define CEPH_OSD_IDLE_TTL_DEFAULT    60
  88 #define CEPH_MOUNT_RSIZE_DEFAULT    (512*1024) /* readahead */
  89 #define CEPH_MAX_READDIR_DEFAULT    1024
  90 #define CEPH_MAX_READDIR_BYTES_DEFAULT    (512*1024)
  91
  92 #define CEPH_MSG_MAX_FRONT_LEN  (16*1024*1024)
  93 #define CEPH_MSG_MAX_DATA_LEN   (16*1024*1024)
  94
  95 #define CEPH_SNAPDIRNAME_DEFAULT ".snap"
  96 #define CEPH_AUTH_NAME_DEFAULT   "guest"
  97 /*
  98  * Delay telling the MDS we no longer want caps, in case we reopen
  99  * the file.  Delay a minimum amount of time, even if we send a cap
 100  * message for some other reason.  Otherwise, take the oppotunity to
 101  * update the mds to avoid sending another message later.
 102  */
 103 #define CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT      5  /* cap release delay */
 104 #define CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT     60  /* cap release delay */
 105
 106 #define CEPH_CAP_RELEASE_SAFETY_DEFAULT        (CEPH_CAPS_PER_RELEASE * 4)
 107
 108 /* mount state */
 109 enum {
 110         CEPH_MOUNT_MOUNTING,
 111         CEPH_MOUNT_MOUNTED,
 112         CEPH_MOUNT_UNMOUNTING,
 113         CEPH_MOUNT_UNMOUNTED,
 114         CEPH_MOUNT_SHUTDOWN,
 115 };
 116
 117 /*
 118  * subtract jiffies
 119  */
 120 static inline unsigned long time_sub(unsigned long a, unsigned long b)
 121 {
 122         BUG_ON(time_after(b, a));
 123         return (long)a - (long)b;
 124 }
 125
 126 /*
 127  * per-filesystem client state
 128  *
 129  * possibly shared by multiple mount points, if they are
 130  * mounting the same ceph filesystem/cluster.
 131  */
 132 struct ceph_client {
 133         struct ceph_fsid fsid;
 134         bool have_fsid;
 135
 136         struct mutex mount_mutex;       /* serialize mount attempts */
 137         struct ceph_mount_args *mount_args;
 138
 139         struct super_block *sb;
 140
 141         unsigned long mount_state;
 142         wait_queue_head_t auth_wq;
 143
 144         int auth_err;
 145
 146         int min_caps;                  /* min caps i added */
 147
 148         struct ceph_messenger *msgr;   /* messenger instance */
 149         struct ceph_mon_client monc;
 150         struct ceph_mds_client mdsc;
 151         struct ceph_osd_client osdc;
 152
 153         /* writeback */
 154         mempool_t *wb_pagevec_pool;
 155         struct workqueue_struct *wb_wq;
 156         struct workqueue_struct *pg_inv_wq;
 157         struct workqueue_struct *trunc_wq;
 158         atomic_long_t writeback_count;
 159
 160         struct backing_dev_info backing_dev_info;
 161
 162 #ifdef CONFIG_DEBUG_FS
 163         struct dentry *debugfs_monmap;
 164         struct dentry *debugfs_mdsmap, *debugfs_osdmap;
 165         struct dentry *debugfs_dir, *debugfs_dentry_lru, *debugfs_caps;
 166         struct dentry *debugfs_congestion_kb;
 167         struct dentry *debugfs_bdi;
 168 #endif
 169 };
 170
 171 /*
 172  * File i/o capability.  This tracks shared state with the metadata
 173  * server that allows us to cache or writeback attributes or to read
 174  * and write data.  For any given inode, we should have one or more
 175  * capabilities, one issued by each metadata server, and our
 176  * cumulative access is the OR of all issued capabilities.
 177  *
 178  * Each cap is referenced by the inode's i_caps rbtree and by per-mds
 179  * session capability lists.
 180  */
 181 struct ceph_cap {
 182         struct ceph_inode_info *ci;
 183         struct rb_node ci_node;          /* per-ci cap tree */
 184         struct ceph_mds_session *session;
 185         struct list_head session_caps;   /* per-session caplist */
 186         int mds;
 187         u64 cap_id;       /* unique cap id (mds provided) */
 188         int issued;       /* latest, from the mds */
 189         int implemented;  /* implemented superset of issued (for revocation) */
 190         int mds_wanted;
 191         u32 seq, issue_seq, mseq;
 192         u32 cap_gen;      /* active/stale cycle */
 193         unsigned long last_used;
 194         struct list_head caps_item;
 195 };
 196
 197 #define CHECK_CAPS_NODELAY    1  /* do not delay any further */
 198 #define CHECK_CAPS_AUTHONLY   2  /* only check auth cap */
 199 #define CHECK_CAPS_FLUSH      4  /* flush any dirty caps */
 200
 201 /*
 202  * Snapped cap state that is pending flush to mds.  When a snapshot occurs,
 203  * we first complete any in-process sync writes and writeback any dirty
 204  * data before flushing the snapped state (tracked here) back to the MDS.
 205  */
 206 struct ceph_cap_snap {
 207         atomic_t nref;
 208         struct ceph_inode_info *ci;
 209         struct list_head ci_item, flushing_item;
 210
 211         u64 follows, flush_tid;
 212         int issued, dirty;
 213         struct ceph_snap_context *context;
 214
 215         mode_t mode;
 216         uid_t uid;
 217         gid_t gid;
 218
 219         struct ceph_buffer *xattr_blob;
 220         u64 xattr_version;
 221
 222         u64 size;
 223         struct timespec mtime, atime, ctime;
 224         u64 time_warp_seq;
 225         int writing;   /* a sync write is still in progress */
 226         int dirty_pages;     /* dirty pages awaiting writeback */
 227 };
 228
 229 static inline void ceph_put_cap_snap(struct ceph_cap_snap *capsnap)
 230 {
 231         if (atomic_dec_and_test(&capsnap->nref)) {
 232                 if (capsnap->xattr_blob)
 233                         ceph_buffer_put(capsnap->xattr_blob);
 234                 kfree(capsnap);
 235         }
 236 }
 237
 238 /*
 239  * The frag tree describes how a directory is fragmented, potentially across
 240  * multiple metadata servers.  It is also used to indicate points where
 241  * metadata authority is delegated, and whether/where metadata is replicated.
 242  *
 243  * A _leaf_ frag will be present in the i_fragtree IFF there is
 244  * delegation info.  That is, if mds >= 0 || ndist > 0.
 245  */
 246 #define CEPH_MAX_DIRFRAG_REP 4
 247
 248 struct ceph_inode_frag {
 249         struct rb_node node;
 250
 251         /* fragtree state */
 252         u32 frag;
 253         int split_by;         /* i.e. 2^(split_by) children */
 254
 255         /* delegation and replication info */
 256         int mds;              /* -1 if same authority as parent */
 257         int ndist;            /* >0 if replicated */
 258         int dist[CEPH_MAX_DIRFRAG_REP];
 259 };
 260
 261 /*
 262  * We cache inode xattrs as an encoded blob until they are first used,
 263  * at which point we parse them into an rbtree.
 264  */
 265 struct ceph_inode_xattr {
 266         struct rb_node node;
 267
 268         const char *name;
 269         int name_len;
 270         const char *val;
 271         int val_len;
 272         int dirty;
 273
 274         int should_free_name;
 275         int should_free_val;
 276 };
 277
 278 struct ceph_inode_xattrs_info {
 279         /*
 280          * (still encoded) xattr blob. we avoid the overhead of parsing
 281          * this until someone actually calls getxattr, etc.
 282          *
 283          * blob->vec.iov_len == 4 implies there are no xattrs; blob ==
 284          * NULL means we don't know.
 285         */
 286         struct ceph_buffer *blob, *prealloc_blob;
 287
 288         struct rb_root index;
 289         bool dirty;
 290         int count;
 291         int names_size;
 292         int vals_size;
 293         u64 version, index_version;
 294 };
 295
 296 /*
 297  * Ceph inode.
 298  */
 299 #define CEPH_I_COMPLETE  1  /* we have complete directory cached */
 300 #define CEPH_I_NODELAY   4  /* do not delay cap release */
 301 #define CEPH_I_FLUSH     8  /* do not delay flush of dirty metadata */
 302 #define CEPH_I_NOFLUSH  16  /* do not flush dirty caps */
 303
 304 struct ceph_inode_info {
 305         struct ceph_vino i_vino;   /* ceph ino + snap */
 306
 307         u64 i_version;
 308         u32 i_time_warp_seq;
 309
 310         unsigned i_ceph_flags;
 311         unsigned long i_release_count;
 312
 313         struct ceph_file_layout i_layout;
 314         char *i_symlink;
 315
 316         /* for dirs */
 317         struct timespec i_rctime;
 318         u64 i_rbytes, i_rfiles, i_rsubdirs;
 319         u64 i_files, i_subdirs;
 320         u64 i_max_offset;  /* largest readdir offset, set with I_COMPLETE */
 321
 322         struct rb_root i_fragtree;
 323         struct mutex i_fragtree_mutex;
 324
 325         struct ceph_inode_xattrs_info i_xattrs;
 326
 327         /* capabilities.  protected _both_ by i_lock and cap->session's
 328          * s_mutex. */
 329         struct rb_root i_caps;           /* cap list */
 330         struct ceph_cap *i_auth_cap;     /* authoritative cap, if any */
 331         unsigned i_dirty_caps, i_flushing_caps;     /* mask of dirtied fields */
 332         struct list_head i_dirty_item, i_flushing_item;
 333         u64 i_cap_flush_seq;
 334         /* we need to track cap writeback on a per-cap-bit basis, to allow
 335          * overlapping, pipelined cap flushes to the mds.  we can probably
 336          * reduce the tid to 8 bits if we're concerned about inode size. */
 337         u16 i_cap_flush_last_tid, i_cap_flush_tid[CEPH_CAP_BITS];
 338         wait_queue_head_t i_cap_wq;      /* threads waiting on a capability */
 339         unsigned long i_hold_caps_min; /* jiffies */
 340         unsigned long i_hold_caps_max; /* jiffies */
 341         struct list_head i_cap_delay_list;  /* for delayed cap release to mds */
 342         int i_cap_exporting_mds;         /* to handle cap migration between */
 343         unsigned i_cap_exporting_mseq;   /*  mds's. */
 344         unsigned i_cap_exporting_issued;
 345         struct ceph_cap_reservation i_cap_migration_resv;
 346         struct list_head i_cap_snaps;   /* snapped state pending flush to mds */
 347         struct ceph_snap_context *i_head_snapc;  /* set if wr_buffer_head > 0 or
 348                                                     dirty|flushing caps */
 349         unsigned i_snap_caps;           /* cap bits for snapped files */
 350
 351         int i_nr_by_mode[CEPH_FILE_MODE_NUM];  /* open file counts */
 352
 353         u32 i_truncate_seq;        /* last truncate to smaller size */
 354         u64 i_truncate_size;       /*  and the size we last truncated down to */
 355         int i_truncate_pending;    /*  still need to call vmtruncate */
 356
 357         u64 i_max_size;            /* max file size authorized by mds */
 358         u64 i_reported_size; /* (max_)size reported to or requested of mds */
 359         u64 i_wanted_max_size;     /* offset we'd like to write too */
 360         u64 i_requested_max_size;  /* max_size we've requested */
 361
 362         /* held references to caps */
 363         int i_pin_ref;
 364         int i_rd_ref, i_rdcache_ref, i_wr_ref;
 365         int i_wrbuffer_ref, i_wrbuffer_ref_head;
 366         u32 i_shared_gen;       /* increment each time we get FILE_SHARED */
 367         u32 i_rdcache_gen;      /* we increment this each time we get
 368                                    FILE_CACHE.  If it's non-zero, we
 369                                    _may_ have cached pages. */
 370         u32 i_rdcache_revoking; /* RDCACHE gen to async invalidate, if any */
 371
 372         struct list_head i_unsafe_writes; /* uncommitted sync writes */
 373         struct list_head i_unsafe_dirops; /* uncommitted mds dir ops */
 374         spinlock_t i_unsafe_lock;
 375
 376         struct ceph_snap_realm *i_snap_realm; /* snap realm (if caps) */
 377         int i_snap_realm_counter; /* snap realm (if caps) */
 378         struct list_head i_snap_realm_item;
 379         struct list_head i_snap_flush_item;
 380
 381         struct work_struct i_wb_work;  /* writeback work */
 382         struct work_struct i_pg_inv_work;  /* page invalidation work */
 383
 384         struct work_struct i_vmtruncate_work;
 385
 386         struct inode vfs_inode; /* at end */
 387 };
 388
 389 static inline struct ceph_inode_info *ceph_inode(struct inode *inode)
 390 {
 391         return container_of(inode, struct ceph_inode_info, vfs_inode);
 392 }
 393
 394 static inline void ceph_i_clear(struct inode *inode, unsigned mask)
 395 {
 396         struct ceph_inode_info *ci = ceph_inode(inode);
 397
 398         spin_lock(&inode->i_lock);
 399         ci->i_ceph_flags &= ~mask;
 400         spin_unlock(&inode->i_lock);
 401 }
 402
 403 static inline void ceph_i_set(struct inode *inode, unsigned mask)
 404 {
 405         struct ceph_inode_info *ci = ceph_inode(inode);
 406
 407         spin_lock(&inode->i_lock);
 408         ci->i_ceph_flags |= mask;
 409         spin_unlock(&inode->i_lock);
 410 }
 411
 412 static inline bool ceph_i_test(struct inode *inode, unsigned mask)
 413 {
 414         struct ceph_inode_info *ci = ceph_inode(inode);
 415         bool r;
 416
 417         smp_mb();
 418         r = (ci->i_ceph_flags & mask) == mask;
 419         return r;
 420 }
 421
 422
 423 /* find a specific frag @f */
 424 extern struct ceph_inode_frag *__ceph_find_frag(struct ceph_inode_info *ci,
 425                                                 u32 f);
 426
 427 /*
 428  * choose fragment for value @v.  copy frag content to pfrag, if leaf
 429  * exists
 430  */
 431 extern u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
 432                             struct ceph_inode_frag *pfrag,
 433                             int *found);
 434
 435 /*
 436  * Ceph dentry state
 437  */
 438 struct ceph_dentry_info {
 439         struct ceph_mds_session *lease_session;
 440         u32 lease_gen, lease_shared_gen;
 441         u32 lease_seq;
 442         unsigned long lease_renew_after, lease_renew_from;
 443         struct list_head lru;
 444         struct dentry *dentry;
 445         u64 time;
 446         u64 offset;
 447 };
 448
 449 static inline struct ceph_dentry_info *ceph_dentry(struct dentry *dentry)
 450 {
 451         return (struct ceph_dentry_info *)dentry->d_fsdata;
 452 }
 453
 454 static inline loff_t ceph_make_fpos(unsigned frag, unsigned off)
 455 {
 456         return ((loff_t)frag << 32) | (loff_t)off;
 457 }
 458
 459 /*
 460  * ino_t is <64 bits on many architectures, blech.
 461  *
 462  * don't include snap in ino hash, at least for now.
 463  */
 464 static inline ino_t ceph_vino_to_ino(struct ceph_vino vino)
 465 {
 466         ino_t ino = (ino_t)vino.ino;  /* ^ (vino.snap << 20); */
 467 #if BITS_PER_LONG == 32
 468         ino ^= vino.ino >> (sizeof(u64)-sizeof(ino_t)) * 8;
 469         if (!ino)
 470                 ino = 1;
 471 #endif
 472         return ino;
 473 }
 474
 475 static inline int ceph_set_ino_cb(struct inode *inode, void *data)
 476 {
 477         ceph_inode(inode)->i_vino = *(struct ceph_vino *)data;
 478         inode->i_ino = ceph_vino_to_ino(*(struct ceph_vino *)data);
 479         return 0;
 480 }
 481
 482 static inline struct ceph_vino ceph_vino(struct inode *inode)
 483 {
 484         return ceph_inode(inode)->i_vino;
 485 }
 486
 487 /* for printf-style formatting */
 488 #define ceph_vinop(i) ceph_inode(i)->i_vino.ino, ceph_inode(i)->i_vino.snap
 489
 490 static inline u64 ceph_ino(struct inode *inode)
 491 {
 492         return ceph_inode(inode)->i_vino.ino;
 493 }
 494 static inline u64 ceph_snap(struct inode *inode)
 495 {
 496         return ceph_inode(inode)->i_vino.snap;
 497 }
 498
 499 static inline int ceph_ino_compare(struct inode *inode, void *data)
 500 {
 501         struct ceph_vino *pvino = (struct ceph_vino *)data;
 502         struct ceph_inode_info *ci = ceph_inode(inode);
 503         return ci->i_vino.ino == pvino->ino &&
 504                 ci->i_vino.snap == pvino->snap;
 505 }
 506
 507 static inline struct inode *ceph_find_inode(struct super_block *sb,
 508                                             struct ceph_vino vino)
 509 {
 510         ino_t t = ceph_vino_to_ino(vino);
 511         return ilookup5(sb, t, ceph_ino_compare, &vino);
 512 }
 513
 514
 515 /*
 516  * caps helpers
 517  */
 518 static inline bool __ceph_is_any_real_caps(struct ceph_inode_info *ci)
 519 {
 520         return !RB_EMPTY_ROOT(&ci->i_caps);
 521 }
 522
 523 extern int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented);
 524 extern int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int t);
 525 extern int __ceph_caps_issued_other(struct ceph_inode_info *ci,
 526                                     struct ceph_cap *cap);
 527
 528 static inline int ceph_caps_issued(struct ceph_inode_info *ci)
 529 {
 530         int issued;
 531         spin_lock(&ci->vfs_inode.i_lock);
 532         issued = __ceph_caps_issued(ci, NULL);
 533         spin_unlock(&ci->vfs_inode.i_lock);
 534         return issued;
 535 }
 536
 537 static inline int ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask,
 538                                         int touch)
 539 {
 540         int r;
 541         spin_lock(&ci->vfs_inode.i_lock);
 542         r = __ceph_caps_issued_mask(ci, mask, touch);
 543         spin_unlock(&ci->vfs_inode.i_lock);
 544         return r;
 545 }
 546
 547 static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
 548 {
 549         return ci->i_dirty_caps | ci->i_flushing_caps;
 550 }
 551 extern void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
 552
 553 extern int ceph_caps_revoking(struct ceph_inode_info *ci, int mask);
 554 extern int __ceph_caps_used(struct ceph_inode_info *ci);
 555
 556 extern int __ceph_caps_file_wanted(struct ceph_inode_info *ci);
 557
 558 /*
 559  * wanted, by virtue of open file modes AND cap refs (buffered/cached data)
 560  */
 561 static inline int __ceph_caps_wanted(struct ceph_inode_info *ci)
 562 {
 563         int w = __ceph_caps_file_wanted(ci) | __ceph_caps_used(ci);
 564         if (w & CEPH_CAP_FILE_BUFFER)
 565                 w |= CEPH_CAP_FILE_EXCL;  /* we want EXCL if dirty data */
 566         return w;
 567 }
 568
 569 /* what the mds thinks we want */
 570 extern int __ceph_caps_mds_wanted(struct ceph_inode_info *ci);
 571
 572 extern void ceph_caps_init(struct ceph_mds_client *mdsc);
 573 extern void ceph_caps_finalize(struct ceph_mds_client *mdsc);
 574 extern void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta);
 575 extern int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 576                              struct ceph_cap_reservation *ctx, int need);
 577 extern int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 578                                struct ceph_cap_reservation *ctx);
 579 extern void ceph_reservation_status(struct ceph_client *client,
 580                                     int *total, int *avail, int *used,
 581                                     int *reserved, int *min);
 582
 583 static inline struct ceph_client *ceph_inode_to_client(struct inode *inode)
 584 {
 585         return (struct ceph_client *)inode->i_sb->s_fs_info;
 586 }
 587
 588 static inline struct ceph_client *ceph_sb_to_client(struct super_block *sb)
 589 {
 590         return (struct ceph_client *)sb->s_fs_info;
 591 }
 592
 593
 594 /*
 595  * we keep buffered readdir results attached to file->private_data
 596  */
 597 struct ceph_file_info {
 598         int fmode;     /* initialized on open */
 599
 600         /* readdir: position within the dir */
 601         u32 frag;
 602         struct ceph_mds_request *last_readdir;
 603         int at_end;
 604
 605         /* readdir: position within a frag */
 606         unsigned offset;       /* offset of last chunk, adjusted for . and .. */
 607         u64 next_offset;       /* offset of next chunk (last_name's + 1) */
 608         char *last_name;       /* last entry in previous chunk */
 609         struct dentry *dentry; /* next dentry (for dcache readdir) */
 610         unsigned long dir_release_count;
 611
 612         /* used for -o dirstat read() on directory thing */
 613         char *dir_info;
 614         int dir_info_len;
 615 };
 616
 617
 618
 619 /*
 620  * snapshots
 621  */
 622
 623 /*
 624  * A "snap context" is the set of existing snapshots when we
 625  * write data.  It is used by the OSD to guide its COW behavior.
 626  *
 627  * The ceph_snap_context is refcounted, and attached to each dirty
 628  * page, indicating which context the dirty data belonged when it was
 629  * dirtied.
 630  */
 631 struct ceph_snap_context {
 632         atomic_t nref;
 633         u64 seq;
 634         int num_snaps;
 635         u64 snaps[];
 636 };
 637
 638 static inline struct ceph_snap_context *
 639 ceph_get_snap_context(struct ceph_snap_context *sc)
 640 {
 641         /*
 642         printk("get_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),
 643                atomic_read(&sc->nref)+1);
 644         */
 645         if (sc)
 646                 atomic_inc(&sc->nref);
 647         return sc;
 648 }
 649
 650 static inline void ceph_put_snap_context(struct ceph_snap_context *sc)
 651 {
 652         if (!sc)
 653                 return;
 654         /*
 655         printk("put_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),
 656                atomic_read(&sc->nref)-1);
 657         */
 658         if (atomic_dec_and_test(&sc->nref)) {
 659                 /*printk(" deleting snap_context %p\n", sc);*/
 660                 kfree(sc);
 661         }
 662 }
 663
 664 /*
 665  * A "snap realm" describes a subset of the file hierarchy sharing
 666  * the same set of snapshots that apply to it.  The realms themselves
 667  * are organized into a hierarchy, such that children inherit (some of)
 668  * the snapshots of their parents.
 669  *
 670  * All inodes within the realm that have capabilities are linked into a
 671  * per-realm list.
 672  */
 673 struct ceph_snap_realm {
 674         u64 ino;
 675         atomic_t nref;
 676         struct rb_node node;
 677
 678         u64 created, seq;
 679         u64 parent_ino;
 680         u64 parent_since;   /* snapid when our current parent became so */
 681
 682         u64 *prior_parent_snaps;      /* snaps inherited from any parents we */
 683         int num_prior_parent_snaps;   /*  had prior to parent_since */
 684         u64 *snaps;                   /* snaps specific to this realm */
 685         int num_snaps;
 686
 687         struct ceph_snap_realm *parent;
 688         struct list_head children;       /* list of child realms */
 689         struct list_head child_item;
 690
 691         struct list_head empty_item;     /* if i have ref==0 */
 692
 693         /* the current set of snaps for this realm */
 694         struct ceph_snap_context *cached_context;
 695
 696         struct list_head inodes_with_caps;
 697         spinlock_t inodes_with_caps_lock;
 698 };
 699
 700
 701
 702 /*
 703  * calculate the number of pages a given length and offset map onto,
 704  * if we align the data.
 705  */
 706 static inline int calc_pages_for(u64 off, u64 len)
 707 {
 708         return ((off+len+PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT) -
 709                 (off >> PAGE_CACHE_SHIFT);
 710 }
 711
 712
 713
 714 /* snap.c */
 715 struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
 716                                                u64 ino);
 717 extern void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
 718                                 struct ceph_snap_realm *realm);
 719 extern void ceph_put_snap_realm(struct ceph_mds_client *mdsc,
 720                                 struct ceph_snap_realm *realm);
 721 extern int ceph_update_snap_trace(struct ceph_mds_client *m,
 722                                   void *p, void *e, bool deletion);
 723 extern void ceph_handle_snap(struct ceph_mds_client *mdsc,
 724                              struct ceph_mds_session *session,
 725                              struct ceph_msg *msg);
 726 extern void ceph_queue_cap_snap(struct ceph_inode_info *ci);
 727 extern int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
 728                                   struct ceph_cap_snap *capsnap);
 729 extern void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc);
 730
 731 /*
 732  * a cap_snap is "pending" if it is still awaiting an in-progress
 733  * sync write (that may/may not still update size, mtime, etc.).
 734  */
 735 static inline bool __ceph_have_pending_cap_snap(struct ceph_inode_info *ci)
 736 {
 737         return !list_empty(&ci->i_cap_snaps) &&
 738                 list_entry(ci->i_cap_snaps.prev, struct ceph_cap_snap,
 739                            ci_item)->writing;
 740 }
 741
 742
 743 /* super.c */
 744 extern struct kmem_cache *ceph_inode_cachep;
 745 extern struct kmem_cache *ceph_cap_cachep;
 746 extern struct kmem_cache *ceph_dentry_cachep;
 747 extern struct kmem_cache *ceph_file_cachep;
 748
 749 extern const char *ceph_msg_type_name(int type);
 750 extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid);
 751
 752 /* inode.c */
 753 extern const struct inode_operations ceph_file_iops;
 754
 755 extern struct inode *ceph_alloc_inode(struct super_block *sb);
 756 extern void ceph_destroy_inode(struct inode *inode);
 757
 758 extern struct inode *ceph_get_inode(struct super_block *sb,
 759                                     struct ceph_vino vino);
 760 extern struct inode *ceph_get_snapdir(struct inode *parent);
 761 extern int ceph_fill_file_size(struct inode *inode, int issued,
 762                                u32 truncate_seq, u64 truncate_size, u64 size);
 763 extern void ceph_fill_file_time(struct inode *inode, int issued,
 764                                 u64 time_warp_seq, struct timespec *ctime,
 765                                 struct timespec *mtime, struct timespec *atime);
 766 extern int ceph_fill_trace(struct super_block *sb,
 767                            struct ceph_mds_request *req,
 768                            struct ceph_mds_session *session);
 769 extern int ceph_readdir_prepopulate(struct ceph_mds_request *req,
 770                                     struct ceph_mds_session *session);
 771
 772 extern int ceph_inode_holds_cap(struct inode *inode, int mask);
 773
 774 extern int ceph_inode_set_size(struct inode *inode, loff_t size);
 775 extern void __ceph_do_pending_vmtruncate(struct inode *inode);
 776 extern void ceph_queue_vmtruncate(struct inode *inode);
 777
 778 extern void ceph_queue_invalidate(struct inode *inode);
 779 extern void ceph_queue_writeback(struct inode *inode);
 780
 781 extern int ceph_do_getattr(struct inode *inode, int mask);
 782 extern int ceph_permission(struct inode *inode, int mask);
 783 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
 784 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
 785                         struct kstat *stat);
 786
 787 /* xattr.c */
 788 extern int ceph_setxattr(struct dentry *, const char *, const void *,
 789                          size_t, int);
 790 extern ssize_t ceph_getxattr(struct dentry *, const char *, void *, size_t);
 791 extern ssize_t ceph_listxattr(struct dentry *, char *, size_t);
 792 extern int ceph_removexattr(struct dentry *, const char *);
 793 extern void __ceph_build_xattrs_blob(struct ceph_inode_info *ci);
 794 extern void __ceph_destroy_xattrs(struct ceph_inode_info *ci);
 795
 796 /* caps.c */
 797 extern const char *ceph_cap_string(int c);
 798 extern void ceph_handle_caps(struct ceph_mds_session *session,
 799                              struct ceph_msg *msg);
 800 extern int ceph_add_cap(struct inode *inode,
 801                         struct ceph_mds_session *session, u64 cap_id,
 802                         int fmode, unsigned issued, unsigned wanted,
 803                         unsigned cap, unsigned seq, u64 realmino, int flags,
 804                         struct ceph_cap_reservation *caps_reservation);
 805 extern void __ceph_remove_cap(struct ceph_cap *cap);
 806 static inline void ceph_remove_cap(struct ceph_cap *cap)
 807 {
 808         struct inode *inode = &cap->ci->vfs_inode;
 809         spin_lock(&inode->i_lock);
 810         __ceph_remove_cap(cap);
 811         spin_unlock(&inode->i_lock);
 812 }
 813 extern void ceph_put_cap(struct ceph_mds_client *mdsc,
 814                          struct ceph_cap *cap);
 815
 816 extern void ceph_queue_caps_release(struct inode *inode);
 817 extern int ceph_write_inode(struct inode *inode, struct writeback_control *wbc);
 818 extern int ceph_fsync(struct file *file, int datasync);
 819 extern void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
 820                                     struct ceph_mds_session *session);
 821 extern struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci,
 822                                              int mds);
 823 extern int ceph_get_cap_mds(struct inode *inode);
 824 extern void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps);
 825 extern void ceph_put_cap_refs(struct ceph_inode_info *ci, int had);
 826 extern void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
 827                                        struct ceph_snap_context *snapc);
 828 extern void __ceph_flush_snaps(struct ceph_inode_info *ci,
 829                                struct ceph_mds_session **psession);
 830 extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
 831                             struct ceph_mds_session *session);
 832 extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
 833 extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
 834
 835 extern int ceph_encode_inode_release(void **p, struct inode *inode,
 836                                      int mds, int drop, int unless, int force);
 837 extern int ceph_encode_dentry_release(void **p, struct dentry *dn,
 838                                       int mds, int drop, int unless);
 839
 840 extern int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
 841                          int *got, loff_t endoff);
 842
 843 /* for counting open files by mode */
 844 static inline void __ceph_get_fmode(struct ceph_inode_info *ci, int mode)
 845 {
 846         ci->i_nr_by_mode[mode]++;
 847 }
 848 extern void ceph_put_fmode(struct ceph_inode_info *ci, int mode);
 849
 850 /* addr.c */
 851 extern const struct address_space_operations ceph_aops;
 852 extern int ceph_mmap(struct file *file, struct vm_area_struct *vma);
 853
 854 /* file.c */
 855 extern const struct file_operations ceph_file_fops;
 856 extern const struct address_space_operations ceph_aops;
 857 extern int ceph_open(struct inode *inode, struct file *file);
 858 extern struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 859                                        struct nameidata *nd, int mode,
 860                                        int locked_dir);
 861 extern int ceph_release(struct inode *inode, struct file *filp);
 862 extern void ceph_release_page_vector(struct page **pages, int num_pages);
 863
 864 /* dir.c */
 865 extern const struct file_operations ceph_dir_fops;
 866 extern const struct inode_operations ceph_dir_iops;
 867 extern const struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
 868         ceph_snapdir_dentry_ops;
 869
 870 extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);
 871 extern struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 872                                          struct dentry *dentry, int err);
 873
 874 extern void ceph_dentry_lru_add(struct dentry *dn);
 875 extern void ceph_dentry_lru_touch(struct dentry *dn);
 876 extern void ceph_dentry_lru_del(struct dentry *dn);
 877 extern void ceph_invalidate_dentry_lease(struct dentry *dentry);
 878
 879 /*
 880  * our d_ops vary depending on whether the inode is live,
 881  * snapshotted (read-only), or a virtual ".snap" directory.
 882  */
 883 int ceph_init_dentry(struct dentry *dentry);
 884
 885
 886 /* ioctl.c */
 887 extern long ceph_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 888
 889 /* export.c */
 890 extern const struct export_operations ceph_export_ops;
 891
 892 /* debugfs.c */
 893 extern int ceph_debugfs_init(void);
 894 extern void ceph_debugfs_cleanup(void);
 895 extern int ceph_debugfs_client_init(struct ceph_client *client);
 896 extern void ceph_debugfs_client_cleanup(struct ceph_client *client);
 897
 898 /* locks.c */
 899 extern int ceph_lock(struct file *file, int cmd, struct file_lock *fl);
 900 extern int ceph_flock(struct file *file, int cmd, struct file_lock *fl);
 901 extern void ceph_count_locks(struct inode *inode, int *p_num, int *f_num);
 902 extern int ceph_encode_locks(struct inode *i, struct ceph_pagelist *p,
 903                              int p_locks, int f_locks);
 904 extern int lock_to_ceph_filelock(struct file_lock *fl, struct ceph_filelock *c);
 905
 906 static inline struct inode *get_dentry_parent_inode(struct dentry *dentry)
 907 {
 908         if (dentry && dentry->d_parent)
 909                 return dentry->d_parent->d_inode;
 910
 911         return NULL;
 912 }
 913
 914 #endif /* _FS_CEPH_SUPER_H */