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  * mount options
  35  */
  36 #define CEPH_OPT_FSID             (1<<0)
  37 #define CEPH_OPT_NOSHARE          (1<<1) /* don't share client with other sbs */
  38 #define CEPH_OPT_MYIP             (1<<2) /* specified my ip */
  39 #define CEPH_OPT_DIRSTAT          (1<<4) /* funky `cat dirname` for stats */
  40 #define CEPH_OPT_RBYTES           (1<<5) /* dir st_bytes = rbytes */
  41 #define CEPH_OPT_NOCRC            (1<<6) /* no data crc on writes */
  42 #define CEPH_OPT_NOASYNCREADDIR   (1<<7) /* no dcache readdir */
  43
  44 #define CEPH_OPT_DEFAULT   (CEPH_OPT_RBYTES)
  45
  46 #define ceph_set_opt(client, opt) \
  47         (client)->mount_args->flags |= CEPH_OPT_##opt;
  48 #define ceph_test_opt(client, opt) \
  49         (!!((client)->mount_args->flags & CEPH_OPT_##opt))
  50
  51
  52 struct ceph_mount_args {
  53         int sb_flags;
  54         int flags;
  55         struct ceph_fsid fsid;
  56         struct ceph_entity_addr my_addr;
  57         int num_mon;
  58         struct ceph_entity_addr *mon_addr;
  59         int mount_timeout;
  60         int osd_idle_ttl;
  61         int osd_timeout;
  62         int osd_keepalive_timeout;
  63         int wsize;
  64         int rsize;            /* max readahead */
  65         int congestion_kb;    /* max writeback in flight */
  66         int caps_wanted_delay_min, caps_wanted_delay_max;
  67         int cap_release_safety;
  68         int max_readdir;       /* max readdir result (entires) */
  69         int max_readdir_bytes; /* max readdir result (bytes) */
  70         char *snapdir_name;   /* default ".snap" */
  71         char *name;
  72         char *secret;
  73 };
  74
  75 /*
  76  * defaults
  77  */
  78 #define CEPH_MOUNT_TIMEOUT_DEFAULT  60
  79 #define CEPH_OSD_TIMEOUT_DEFAULT    60  /* seconds */
  80 #define CEPH_OSD_KEEPALIVE_DEFAULT  5
  81 #define CEPH_OSD_IDLE_TTL_DEFAULT    60
  82 #define CEPH_MOUNT_RSIZE_DEFAULT    (512*1024) /* readahead */
  83 #define CEPH_MAX_READDIR_DEFAULT    1024
  84 #define CEPH_MAX_READDIR_BYTES_DEFAULT    (512*1024)
  85
  86 #define CEPH_MSG_MAX_FRONT_LEN  (16*1024*1024)
  87 #define CEPH_MSG_MAX_DATA_LEN   (16*1024*1024)
  88
  89 #define CEPH_SNAPDIRNAME_DEFAULT ".snap"
  90 #define CEPH_AUTH_NAME_DEFAULT   "guest"
  91 /*
  92  * Delay telling the MDS we no longer want caps, in case we reopen
  93  * the file.  Delay a minimum amount of time, even if we send a cap
  94  * message for some other reason.  Otherwise, take the oppotunity to
  95  * update the mds to avoid sending another message later.
  96  */
  97 #define CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT      5  /* cap release delay */
  98 #define CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT     60  /* cap release delay */
  99
 100 #define CEPH_CAP_RELEASE_SAFETY_DEFAULT        (CEPH_CAPS_PER_RELEASE * 4)
 101
 102 /* mount state */
 103 enum {
 104         CEPH_MOUNT_MOUNTING,
 105         CEPH_MOUNT_MOUNTED,
 106         CEPH_MOUNT_UNMOUNTING,
 107         CEPH_MOUNT_UNMOUNTED,
 108         CEPH_MOUNT_SHUTDOWN,
 109 };
 110
 111 /*
 112  * subtract jiffies
 113  */
 114 static inline unsigned long time_sub(unsigned long a, unsigned long b)
 115 {
 116         BUG_ON(time_after(b, a));
 117         return (long)a - (long)b;
 118 }
 119
 120 /*
 121  * per-filesystem client state
 122  *
 123  * possibly shared by multiple mount points, if they are
 124  * mounting the same ceph filesystem/cluster.
 125  */
 126 struct ceph_client {
 127         struct ceph_fsid fsid;
 128         bool have_fsid;
 129
 130         struct mutex mount_mutex;       /* serialize mount attempts */
 131         struct ceph_mount_args *mount_args;
 132
 133         struct super_block *sb;
 134
 135         unsigned long mount_state;
 136         wait_queue_head_t auth_wq;
 137
 138         int auth_err;
 139
 140         int min_caps;                  /* min caps i added */
 141
 142         struct ceph_messenger *msgr;   /* messenger instance */
 143         struct ceph_mon_client monc;
 144         struct ceph_mds_client mdsc;
 145         struct ceph_osd_client osdc;
 146
 147         /* writeback */
 148         mempool_t *wb_pagevec_pool;
 149         struct workqueue_struct *wb_wq;
 150         struct workqueue_struct *pg_inv_wq;
 151         struct workqueue_struct *trunc_wq;
 152         atomic_long_t writeback_count;
 153
 154         struct backing_dev_info backing_dev_info;
 155
 156 #ifdef CONFIG_DEBUG_FS
 157         struct dentry *debugfs_monmap;
 158         struct dentry *debugfs_mdsmap, *debugfs_osdmap;
 159         struct dentry *debugfs_dir, *debugfs_dentry_lru, *debugfs_caps;
 160         struct dentry *debugfs_congestion_kb;
 161         struct dentry *debugfs_bdi;
 162 #endif
 163 };
 164
 165 /*
 166  * File i/o capability.  This tracks shared state with the metadata
 167  * server that allows us to cache or writeback attributes or to read
 168  * and write data.  For any given inode, we should have one or more
 169  * capabilities, one issued by each metadata server, and our
 170  * cumulative access is the OR of all issued capabilities.
 171  *
 172  * Each cap is referenced by the inode's i_caps rbtree and by per-mds
 173  * session capability lists.
 174  */
 175 struct ceph_cap {
 176         struct ceph_inode_info *ci;
 177         struct rb_node ci_node;          /* per-ci cap tree */
 178         struct ceph_mds_session *session;
 179         struct list_head session_caps;   /* per-session caplist */
 180         int mds;
 181         u64 cap_id;       /* unique cap id (mds provided) */
 182         int issued;       /* latest, from the mds */
 183         int implemented;  /* implemented superset of issued (for revocation) */
 184         int mds_wanted;
 185         u32 seq, issue_seq, mseq;
 186         u32 cap_gen;      /* active/stale cycle */
 187         unsigned long last_used;
 188         struct list_head caps_item;
 189 };
 190
 191 #define CHECK_CAPS_NODELAY    1  /* do not delay any further */
 192 #define CHECK_CAPS_AUTHONLY   2  /* only check auth cap */
 193 #define CHECK_CAPS_FLUSH      4  /* flush any dirty caps */
 194
 195 /*
 196  * Snapped cap state that is pending flush to mds.  When a snapshot occurs,
 197  * we first complete any in-process sync writes and writeback any dirty
 198  * data before flushing the snapped state (tracked here) back to the MDS.
 199  */
 200 struct ceph_cap_snap {
 201         atomic_t nref;
 202         struct ceph_inode_info *ci;
 203         struct list_head ci_item, flushing_item;
 204
 205         u64 follows, flush_tid;
 206         int issued, dirty;
 207         struct ceph_snap_context *context;
 208
 209         mode_t mode;
 210         uid_t uid;
 211         gid_t gid;
 212
 213         void *xattr_blob;
 214         int xattr_len;
 215         u64 xattr_version;
 216
 217         u64 size;
 218         struct timespec mtime, atime, ctime;
 219         u64 time_warp_seq;
 220         int writing;   /* a sync write is still in progress */
 221         int dirty_pages;     /* dirty pages awaiting writeback */
 222 };
 223
 224 static inline void ceph_put_cap_snap(struct ceph_cap_snap *capsnap)
 225 {
 226         if (atomic_dec_and_test(&capsnap->nref))
 227                 kfree(capsnap);
 228 }
 229
 230 /*
 231  * The frag tree describes how a directory is fragmented, potentially across
 232  * multiple metadata servers.  It is also used to indicate points where
 233  * metadata authority is delegated, and whether/where metadata is replicated.
 234  *
 235  * A _leaf_ frag will be present in the i_fragtree IFF there is
 236  * delegation info.  That is, if mds >= 0 || ndist > 0.
 237  */
 238 #define CEPH_MAX_DIRFRAG_REP 4
 239
 240 struct ceph_inode_frag {
 241         struct rb_node node;
 242
 243         /* fragtree state */
 244         u32 frag;
 245         int split_by;         /* i.e. 2^(split_by) children */
 246
 247         /* delegation and replication info */
 248         int mds;              /* -1 if same authority as parent */
 249         int ndist;            /* >0 if replicated */
 250         int dist[CEPH_MAX_DIRFRAG_REP];
 251 };
 252
 253 /*
 254  * We cache inode xattrs as an encoded blob until they are first used,
 255  * at which point we parse them into an rbtree.
 256  */
 257 struct ceph_inode_xattr {
 258         struct rb_node node;
 259
 260         const char *name;
 261         int name_len;
 262         const char *val;
 263         int val_len;
 264         int dirty;
 265
 266         int should_free_name;
 267         int should_free_val;
 268 };
 269
 270 struct ceph_inode_xattrs_info {
 271         /*
 272          * (still encoded) xattr blob. we avoid the overhead of parsing
 273          * this until someone actually calls getxattr, etc.
 274          *
 275          * blob->vec.iov_len == 4 implies there are no xattrs; blob ==
 276          * NULL means we don't know.
 277         */
 278         struct ceph_buffer *blob, *prealloc_blob;
 279
 280         struct rb_root index;
 281         bool dirty;
 282         int count;
 283         int names_size;
 284         int vals_size;
 285         u64 version, index_version;
 286 };
 287
 288 /*
 289  * Ceph inode.
 290  */
 291 #define CEPH_I_COMPLETE  1  /* we have complete directory cached */
 292 #define CEPH_I_NODELAY   4  /* do not delay cap release */
 293 #define CEPH_I_FLUSH     8  /* do not delay flush of dirty metadata */
 294 #define CEPH_I_NOFLUSH  16  /* do not flush dirty caps */
 295
 296 struct ceph_inode_info {
 297         struct ceph_vino i_vino;   /* ceph ino + snap */
 298
 299         u64 i_version;
 300         u32 i_time_warp_seq;
 301
 302         unsigned i_ceph_flags;
 303         unsigned long i_release_count;
 304
 305         struct ceph_file_layout i_layout;
 306         char *i_symlink;
 307
 308         /* for dirs */
 309         struct timespec i_rctime;
 310         u64 i_rbytes, i_rfiles, i_rsubdirs;
 311         u64 i_files, i_subdirs;
 312         u64 i_max_offset;  /* largest readdir offset, set with I_COMPLETE */
 313
 314         struct rb_root i_fragtree;
 315         struct mutex i_fragtree_mutex;
 316
 317         struct ceph_inode_xattrs_info i_xattrs;
 318
 319         /* capabilities.  protected _both_ by i_lock and cap->session's
 320          * s_mutex. */
 321         struct rb_root i_caps;           /* cap list */
 322         struct ceph_cap *i_auth_cap;     /* authoritative cap, if any */
 323         unsigned i_dirty_caps, i_flushing_caps;     /* mask of dirtied fields */
 324         struct list_head i_dirty_item, i_flushing_item;
 325         u64 i_cap_flush_seq;
 326         /* we need to track cap writeback on a per-cap-bit basis, to allow
 327          * overlapping, pipelined cap flushes to the mds.  we can probably
 328          * reduce the tid to 8 bits if we're concerned about inode size. */
 329         u16 i_cap_flush_last_tid, i_cap_flush_tid[CEPH_CAP_BITS];
 330         wait_queue_head_t i_cap_wq;      /* threads waiting on a capability */
 331         unsigned long i_hold_caps_min; /* jiffies */
 332         unsigned long i_hold_caps_max; /* jiffies */
 333         struct list_head i_cap_delay_list;  /* for delayed cap release to mds */
 334         int i_cap_exporting_mds;         /* to handle cap migration between */
 335         unsigned i_cap_exporting_mseq;   /*  mds's. */
 336         unsigned i_cap_exporting_issued;
 337         struct ceph_cap_reservation i_cap_migration_resv;
 338         struct list_head i_cap_snaps;   /* snapped state pending flush to mds */
 339         struct ceph_snap_context *i_head_snapc;  /* set if wr_buffer_head > 0 */
 340         unsigned i_snap_caps;           /* cap bits for snapped files */
 341
 342         int i_nr_by_mode[CEPH_FILE_MODE_NUM];  /* open file counts */
 343
 344         u32 i_truncate_seq;        /* last truncate to smaller size */
 345         u64 i_truncate_size;       /*  and the size we last truncated down to */
 346         int i_truncate_pending;    /*  still need to call vmtruncate */
 347
 348         u64 i_max_size;            /* max file size authorized by mds */
 349         u64 i_reported_size; /* (max_)size reported to or requested of mds */
 350         u64 i_wanted_max_size;     /* offset we'd like to write too */
 351         u64 i_requested_max_size;  /* max_size we've requested */
 352
 353         /* held references to caps */
 354         int i_pin_ref;
 355         int i_rd_ref, i_rdcache_ref, i_wr_ref;
 356         int i_wrbuffer_ref, i_wrbuffer_ref_head;
 357         u32 i_shared_gen;       /* increment each time we get FILE_SHARED */
 358         u32 i_rdcache_gen;      /* we increment this each time we get
 359                                    FILE_CACHE.  If it's non-zero, we
 360                                    _may_ have cached pages. */
 361         u32 i_rdcache_revoking; /* RDCACHE gen to async invalidate, if any */
 362
 363         struct list_head i_unsafe_writes; /* uncommitted sync writes */
 364         struct list_head i_unsafe_dirops; /* uncommitted mds dir ops */
 365         spinlock_t i_unsafe_lock;
 366
 367         struct ceph_snap_realm *i_snap_realm; /* snap realm (if caps) */
 368         int i_snap_realm_counter; /* snap realm (if caps) */
 369         struct list_head i_snap_realm_item;
 370         struct list_head i_snap_flush_item;
 371
 372         struct work_struct i_wb_work;  /* writeback work */
 373         struct work_struct i_pg_inv_work;  /* page invalidation work */
 374
 375         struct work_struct i_vmtruncate_work;
 376
 377         struct inode vfs_inode; /* at end */
 378 };
 379
 380 static inline struct ceph_inode_info *ceph_inode(struct inode *inode)
 381 {
 382         return container_of(inode, struct ceph_inode_info, vfs_inode);
 383 }
 384
 385 static inline void ceph_i_clear(struct inode *inode, unsigned mask)
 386 {
 387         struct ceph_inode_info *ci = ceph_inode(inode);
 388
 389         spin_lock(&inode->i_lock);
 390         ci->i_ceph_flags &= ~mask;
 391         spin_unlock(&inode->i_lock);
 392 }
 393
 394 static inline void ceph_i_set(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 bool ceph_i_test(struct inode *inode, unsigned mask)
 404 {
 405         struct ceph_inode_info *ci = ceph_inode(inode);
 406         bool r;
 407
 408         smp_mb();
 409         r = (ci->i_ceph_flags & mask) == mask;
 410         return r;
 411 }
 412
 413
 414 /* find a specific frag @f */
 415 extern struct ceph_inode_frag *__ceph_find_frag(struct ceph_inode_info *ci,
 416                                                 u32 f);
 417
 418 /*
 419  * choose fragment for value @v.  copy frag content to pfrag, if leaf
 420  * exists
 421  */
 422 extern u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
 423                             struct ceph_inode_frag *pfrag,
 424                             int *found);
 425
 426 /*
 427  * Ceph dentry state
 428  */
 429 struct ceph_dentry_info {
 430         struct ceph_mds_session *lease_session;
 431         u32 lease_gen, lease_shared_gen;
 432         u32 lease_seq;
 433         unsigned long lease_renew_after, lease_renew_from;
 434         struct list_head lru;
 435         struct dentry *dentry;
 436         u64 time;
 437         u64 offset;
 438 };
 439
 440 static inline struct ceph_dentry_info *ceph_dentry(struct dentry *dentry)
 441 {
 442         return (struct ceph_dentry_info *)dentry->d_fsdata;
 443 }
 444
 445 static inline loff_t ceph_make_fpos(unsigned frag, unsigned off)
 446 {
 447         return ((loff_t)frag << 32) | (loff_t)off;
 448 }
 449
 450 /*
 451  * ino_t is <64 bits on many architectures, blech.
 452  *
 453  * don't include snap in ino hash, at least for now.
 454  */
 455 static inline ino_t ceph_vino_to_ino(struct ceph_vino vino)
 456 {
 457         ino_t ino = (ino_t)vino.ino;  /* ^ (vino.snap << 20); */
 458 #if BITS_PER_LONG == 32
 459         ino ^= vino.ino >> (sizeof(u64)-sizeof(ino_t)) * 8;
 460         if (!ino)
 461                 ino = 1;
 462 #endif
 463         return ino;
 464 }
 465
 466 static inline int ceph_set_ino_cb(struct inode *inode, void *data)
 467 {
 468         ceph_inode(inode)->i_vino = *(struct ceph_vino *)data;
 469         inode->i_ino = ceph_vino_to_ino(*(struct ceph_vino *)data);
 470         return 0;
 471 }
 472
 473 static inline struct ceph_vino ceph_vino(struct inode *inode)
 474 {
 475         return ceph_inode(inode)->i_vino;
 476 }
 477
 478 /* for printf-style formatting */
 479 #define ceph_vinop(i) ceph_inode(i)->i_vino.ino, ceph_inode(i)->i_vino.snap
 480
 481 static inline u64 ceph_ino(struct inode *inode)
 482 {
 483         return ceph_inode(inode)->i_vino.ino;
 484 }
 485 static inline u64 ceph_snap(struct inode *inode)
 486 {
 487         return ceph_inode(inode)->i_vino.snap;
 488 }
 489
 490 static inline int ceph_ino_compare(struct inode *inode, void *data)
 491 {
 492         struct ceph_vino *pvino = (struct ceph_vino *)data;
 493         struct ceph_inode_info *ci = ceph_inode(inode);
 494         return ci->i_vino.ino == pvino->ino &&
 495                 ci->i_vino.snap == pvino->snap;
 496 }
 497
 498 static inline struct inode *ceph_find_inode(struct super_block *sb,
 499                                             struct ceph_vino vino)
 500 {
 501         ino_t t = ceph_vino_to_ino(vino);
 502         return ilookup5(sb, t, ceph_ino_compare, &vino);
 503 }
 504
 505
 506 /*
 507  * caps helpers
 508  */
 509 static inline bool __ceph_is_any_real_caps(struct ceph_inode_info *ci)
 510 {
 511         return !RB_EMPTY_ROOT(&ci->i_caps);
 512 }
 513
 514 extern int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented);
 515 extern int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int t);
 516 extern int __ceph_caps_issued_other(struct ceph_inode_info *ci,
 517                                     struct ceph_cap *cap);
 518
 519 static inline int ceph_caps_issued(struct ceph_inode_info *ci)
 520 {
 521         int issued;
 522         spin_lock(&ci->vfs_inode.i_lock);
 523         issued = __ceph_caps_issued(ci, NULL);
 524         spin_unlock(&ci->vfs_inode.i_lock);
 525         return issued;
 526 }
 527
 528 static inline int ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask,
 529                                         int touch)
 530 {
 531         int r;
 532         spin_lock(&ci->vfs_inode.i_lock);
 533         r = __ceph_caps_issued_mask(ci, mask, touch);
 534         spin_unlock(&ci->vfs_inode.i_lock);
 535         return r;
 536 }
 537
 538 static inline int __ceph_caps_dirty(struct ceph_inode_info *ci)
 539 {
 540         return ci->i_dirty_caps | ci->i_flushing_caps;
 541 }
 542 extern void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask);
 543
 544 extern int ceph_caps_revoking(struct ceph_inode_info *ci, int mask);
 545 extern int __ceph_caps_used(struct ceph_inode_info *ci);
 546
 547 extern int __ceph_caps_file_wanted(struct ceph_inode_info *ci);
 548
 549 /*
 550  * wanted, by virtue of open file modes AND cap refs (buffered/cached data)
 551  */
 552 static inline int __ceph_caps_wanted(struct ceph_inode_info *ci)
 553 {
 554         int w = __ceph_caps_file_wanted(ci) | __ceph_caps_used(ci);
 555         if (w & CEPH_CAP_FILE_BUFFER)
 556                 w |= CEPH_CAP_FILE_EXCL;  /* we want EXCL if dirty data */
 557         return w;
 558 }
 559
 560 /* what the mds thinks we want */
 561 extern int __ceph_caps_mds_wanted(struct ceph_inode_info *ci);
 562
 563 extern void ceph_caps_init(void);
 564 extern void ceph_caps_finalize(void);
 565 extern void ceph_adjust_min_caps(int delta);
 566 extern int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need);
 567 extern int ceph_unreserve_caps(struct ceph_cap_reservation *ctx);
 568 extern void ceph_reservation_status(struct ceph_client *client,
 569                                     int *total, int *avail, int *used,
 570                                     int *reserved, int *min);
 571
 572 static inline struct ceph_client *ceph_inode_to_client(struct inode *inode)
 573 {
 574         return (struct ceph_client *)inode->i_sb->s_fs_info;
 575 }
 576
 577 static inline struct ceph_client *ceph_sb_to_client(struct super_block *sb)
 578 {
 579         return (struct ceph_client *)sb->s_fs_info;
 580 }
 581
 582
 583 /*
 584  * we keep buffered readdir results attached to file->private_data
 585  */
 586 struct ceph_file_info {
 587         int fmode;     /* initialized on open */
 588
 589         /* readdir: position within the dir */
 590         u32 frag;
 591         struct ceph_mds_request *last_readdir;
 592         int at_end;
 593
 594         /* readdir: position within a frag */
 595         unsigned offset;       /* offset of last chunk, adjusted for . and .. */
 596         u64 next_offset;       /* offset of next chunk (last_name's + 1) */
 597         char *last_name;       /* last entry in previous chunk */
 598         struct dentry *dentry; /* next dentry (for dcache readdir) */
 599         unsigned long dir_release_count;
 600
 601         /* used for -o dirstat read() on directory thing */
 602         char *dir_info;
 603         int dir_info_len;
 604 };
 605
 606
 607
 608 /*
 609  * snapshots
 610  */
 611
 612 /*
 613  * A "snap context" is the set of existing snapshots when we
 614  * write data.  It is used by the OSD to guide its COW behavior.
 615  *
 616  * The ceph_snap_context is refcounted, and attached to each dirty
 617  * page, indicating which context the dirty data belonged when it was
 618  * dirtied.
 619  */
 620 struct ceph_snap_context {
 621         atomic_t nref;
 622         u64 seq;
 623         int num_snaps;
 624         u64 snaps[];
 625 };
 626
 627 static inline struct ceph_snap_context *
 628 ceph_get_snap_context(struct ceph_snap_context *sc)
 629 {
 630         /*
 631         printk("get_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),
 632                atomic_read(&sc->nref)+1);
 633         */
 634         if (sc)
 635                 atomic_inc(&sc->nref);
 636         return sc;
 637 }
 638
 639 static inline void ceph_put_snap_context(struct ceph_snap_context *sc)
 640 {
 641         if (!sc)
 642                 return;
 643         /*
 644         printk("put_snap_context %p %d -> %d\n", sc, atomic_read(&sc->nref),
 645                atomic_read(&sc->nref)-1);
 646         */
 647         if (atomic_dec_and_test(&sc->nref)) {
 648                 /*printk(" deleting snap_context %p\n", sc);*/
 649                 kfree(sc);
 650         }
 651 }
 652
 653 /*
 654  * A "snap realm" describes a subset of the file hierarchy sharing
 655  * the same set of snapshots that apply to it.  The realms themselves
 656  * are organized into a hierarchy, such that children inherit (some of)
 657  * the snapshots of their parents.
 658  *
 659  * All inodes within the realm that have capabilities are linked into a
 660  * per-realm list.
 661  */
 662 struct ceph_snap_realm {
 663         u64 ino;
 664         atomic_t nref;
 665         struct rb_node node;
 666
 667         u64 created, seq;
 668         u64 parent_ino;
 669         u64 parent_since;   /* snapid when our current parent became so */
 670
 671         u64 *prior_parent_snaps;      /* snaps inherited from any parents we */
 672         int num_prior_parent_snaps;   /*  had prior to parent_since */
 673         u64 *snaps;                   /* snaps specific to this realm */
 674         int num_snaps;
 675
 676         struct ceph_snap_realm *parent;
 677         struct list_head children;       /* list of child realms */
 678         struct list_head child_item;
 679
 680         struct list_head empty_item;     /* if i have ref==0 */
 681
 682         /* the current set of snaps for this realm */
 683         struct ceph_snap_context *cached_context;
 684
 685         struct list_head inodes_with_caps;
 686         spinlock_t inodes_with_caps_lock;
 687 };
 688
 689
 690
 691 /*
 692  * calculate the number of pages a given length and offset map onto,
 693  * if we align the data.
 694  */
 695 static inline int calc_pages_for(u64 off, u64 len)
 696 {
 697         return ((off+len+PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT) -
 698                 (off >> PAGE_CACHE_SHIFT);
 699 }
 700
 701
 702
 703 /* snap.c */
 704 struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
 705                                                u64 ino);
 706 extern void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
 707                                 struct ceph_snap_realm *realm);
 708 extern void ceph_put_snap_realm(struct ceph_mds_client *mdsc,
 709                                 struct ceph_snap_realm *realm);
 710 extern int ceph_update_snap_trace(struct ceph_mds_client *m,
 711                                   void *p, void *e, bool deletion);
 712 extern void ceph_handle_snap(struct ceph_mds_client *mdsc,
 713                              struct ceph_mds_session *session,
 714                              struct ceph_msg *msg);
 715 extern void ceph_queue_cap_snap(struct ceph_inode_info *ci);
 716 extern int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
 717                                   struct ceph_cap_snap *capsnap);
 718 extern void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc);
 719
 720 /*
 721  * a cap_snap is "pending" if it is still awaiting an in-progress
 722  * sync write (that may/may not still update size, mtime, etc.).
 723  */
 724 static inline bool __ceph_have_pending_cap_snap(struct ceph_inode_info *ci)
 725 {
 726         return !list_empty(&ci->i_cap_snaps) &&
 727                 list_entry(ci->i_cap_snaps.prev, struct ceph_cap_snap,
 728                            ci_item)->writing;
 729 }
 730
 731
 732 /* super.c */
 733 extern struct kmem_cache *ceph_inode_cachep;
 734 extern struct kmem_cache *ceph_cap_cachep;
 735 extern struct kmem_cache *ceph_dentry_cachep;
 736 extern struct kmem_cache *ceph_file_cachep;
 737
 738 extern const char *ceph_msg_type_name(int type);
 739 extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid);
 740
 741 #define FSID_FORMAT "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-" \
 742         "%02x%02x%02x%02x%02x%02x"
 743 #define PR_FSID(f) (f)->fsid[0], (f)->fsid[1], (f)->fsid[2], (f)->fsid[3], \
 744                 (f)->fsid[4], (f)->fsid[5], (f)->fsid[6], (f)->fsid[7],    \
 745                 (f)->fsid[8], (f)->fsid[9], (f)->fsid[10], (f)->fsid[11],  \
 746                 (f)->fsid[12], (f)->fsid[13], (f)->fsid[14], (f)->fsid[15]
 747
 748 /* inode.c */
 749 extern const struct inode_operations ceph_file_iops;
 750
 751 extern struct inode *ceph_alloc_inode(struct super_block *sb);
 752 extern void ceph_destroy_inode(struct inode *inode);
 753
 754 extern struct inode *ceph_get_inode(struct super_block *sb,
 755                                     struct ceph_vino vino);
 756 extern struct inode *ceph_get_snapdir(struct inode *parent);
 757 extern int ceph_fill_file_size(struct inode *inode, int issued,
 758                                u32 truncate_seq, u64 truncate_size, u64 size);
 759 extern void ceph_fill_file_time(struct inode *inode, int issued,
 760                                 u64 time_warp_seq, struct timespec *ctime,
 761                                 struct timespec *mtime, struct timespec *atime);
 762 extern int ceph_fill_trace(struct super_block *sb,
 763                            struct ceph_mds_request *req,
 764                            struct ceph_mds_session *session);
 765 extern int ceph_readdir_prepopulate(struct ceph_mds_request *req,
 766                                     struct ceph_mds_session *session);
 767
 768 extern int ceph_inode_holds_cap(struct inode *inode, int mask);
 769
 770 extern int ceph_inode_set_size(struct inode *inode, loff_t size);
 771 extern void __ceph_do_pending_vmtruncate(struct inode *inode);
 772 extern void ceph_queue_vmtruncate(struct inode *inode);
 773
 774 extern void ceph_queue_invalidate(struct inode *inode);
 775 extern void ceph_queue_writeback(struct inode *inode);
 776
 777 extern int ceph_do_getattr(struct inode *inode, int mask);
 778 extern int ceph_permission(struct inode *inode, int mask);
 779 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
 780 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
 781                         struct kstat *stat);
 782
 783 /* xattr.c */
 784 extern int ceph_setxattr(struct dentry *, const char *, const void *,
 785                          size_t, int);
 786 extern ssize_t ceph_getxattr(struct dentry *, const char *, void *, size_t);
 787 extern ssize_t ceph_listxattr(struct dentry *, char *, size_t);
 788 extern int ceph_removexattr(struct dentry *, const char *);
 789 extern void __ceph_build_xattrs_blob(struct ceph_inode_info *ci);
 790 extern void __ceph_destroy_xattrs(struct ceph_inode_info *ci);
 791
 792 /* caps.c */
 793 extern const char *ceph_cap_string(int c);
 794 extern void ceph_handle_caps(struct ceph_mds_session *session,
 795                              struct ceph_msg *msg);
 796 extern int ceph_add_cap(struct inode *inode,
 797                         struct ceph_mds_session *session, u64 cap_id,
 798                         int fmode, unsigned issued, unsigned wanted,
 799                         unsigned cap, unsigned seq, u64 realmino, int flags,
 800                         struct ceph_cap_reservation *caps_reservation);
 801 extern void __ceph_remove_cap(struct ceph_cap *cap);
 802 static inline void ceph_remove_cap(struct ceph_cap *cap)
 803 {
 804         struct inode *inode = &cap->ci->vfs_inode;
 805         spin_lock(&inode->i_lock);
 806         __ceph_remove_cap(cap);
 807         spin_unlock(&inode->i_lock);
 808 }
 809 extern void ceph_put_cap(struct ceph_cap *cap);
 810
 811 extern void ceph_queue_caps_release(struct inode *inode);
 812 extern int ceph_write_inode(struct inode *inode, struct writeback_control *wbc);
 813 extern int ceph_fsync(struct file *file, int datasync);
 814 extern void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
 815                                     struct ceph_mds_session *session);
 816 extern int ceph_get_cap_mds(struct inode *inode);
 817 extern void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps);
 818 extern void ceph_put_cap_refs(struct ceph_inode_info *ci, int had);
 819 extern void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
 820                                        struct ceph_snap_context *snapc);
 821 extern void __ceph_flush_snaps(struct ceph_inode_info *ci,
 822                                struct ceph_mds_session **psession);
 823 extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
 824                             struct ceph_mds_session *session);
 825 extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
 826 extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
 827
 828 extern int ceph_encode_inode_release(void **p, struct inode *inode,
 829                                      int mds, int drop, int unless, int force);
 830 extern int ceph_encode_dentry_release(void **p, struct dentry *dn,
 831                                       int mds, int drop, int unless);
 832
 833 extern int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
 834                          int *got, loff_t endoff);
 835
 836 /* for counting open files by mode */
 837 static inline void __ceph_get_fmode(struct ceph_inode_info *ci, int mode)
 838 {
 839         ci->i_nr_by_mode[mode]++;
 840 }
 841 extern void ceph_put_fmode(struct ceph_inode_info *ci, int mode);
 842
 843 /* addr.c */
 844 extern const struct address_space_operations ceph_aops;
 845 extern int ceph_mmap(struct file *file, struct vm_area_struct *vma);
 846
 847 /* file.c */
 848 extern const struct file_operations ceph_file_fops;
 849 extern const struct address_space_operations ceph_aops;
 850 extern int ceph_open(struct inode *inode, struct file *file);
 851 extern struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 852                                        struct nameidata *nd, int mode,
 853                                        int locked_dir);
 854 extern int ceph_release(struct inode *inode, struct file *filp);
 855 extern void ceph_release_page_vector(struct page **pages, int num_pages);
 856
 857 /* dir.c */
 858 extern const struct file_operations ceph_dir_fops;
 859 extern const struct inode_operations ceph_dir_iops;
 860 extern struct dentry_operations ceph_dentry_ops, ceph_snap_dentry_ops,
 861         ceph_snapdir_dentry_ops;
 862
 863 extern int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry);
 864 extern struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 865                                          struct dentry *dentry, int err);
 866
 867 extern void ceph_dentry_lru_add(struct dentry *dn);
 868 extern void ceph_dentry_lru_touch(struct dentry *dn);
 869 extern void ceph_dentry_lru_del(struct dentry *dn);
 870 extern void ceph_invalidate_dentry_lease(struct dentry *dentry);
 871
 872 /*
 873  * our d_ops vary depending on whether the inode is live,
 874  * snapshotted (read-only), or a virtual ".snap" directory.
 875  */
 876 int ceph_init_dentry(struct dentry *dentry);
 877
 878
 879 /* ioctl.c */
 880 extern long ceph_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 881
 882 /* export.c */
 883 extern const struct export_operations ceph_export_ops;
 884
 885 /* debugfs.c */
 886 extern int ceph_debugfs_init(void);
 887 extern void ceph_debugfs_cleanup(void);
 888 extern int ceph_debugfs_client_init(struct ceph_client *client);
 889 extern void ceph_debugfs_client_cleanup(struct ceph_client *client);
 890
 891 static inline struct inode *get_dentry_parent_inode(struct dentry *dentry)
 892 {
 893         if (dentry && dentry->d_parent)
 894                 return dentry->d_parent->d_inode;
 895
 896         return NULL;
 897 }
 898
 899 #endif /* _FS_CEPH_SUPER_H */