drivers/block/rbd_types.h

   1 /*
   2  * Ceph - scalable distributed file system
   3  *
   4  * Copyright (C) 2004-2010 Sage Weil <sage@newdream.net>
   5  *
   6  * This is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License version 2.1, as published by the Free Software
   9  * Foundation.  See file COPYING.
  10  *
  11  */
  12
  13 #ifndef CEPH_RBD_TYPES_H
  14 #define CEPH_RBD_TYPES_H
  15
  16 #include <linux/types.h>
  17
  18 /* For format version 2, rbd image 'foo' consists of objects
  19  *   rbd_id.foo         - id of image
  20  *   rbd_header.<id>    - image metadata
  21  *   rbd_data.<id>.0000000000000000
  22  *   rbd_data.<id>.0000000000000001
  23  *   ...                - data
  24  * Clients do not access header data directly in rbd format 2.
  25  */
  26
  27 #define RBD_HEADER_PREFIX      "rbd_header."
  28 #define RBD_DATA_PREFIX        "rbd_data."
  29 #define RBD_ID_PREFIX          "rbd_id."
  30
  31 /*
  32  * For format version 1, rbd image 'foo' consists of objects
  33  *   foo.rbd            - image metadata
  34  *   rb.<idhi>.<idlo>.00000000
  35  *   rb.<idhi>.<idlo>.00000001
  36  *   ...                - data
  37  * There is no notion of a persistent image id in rbd format 1.
  38  */
  39
  40 #define RBD_SUFFIX              ".rbd"
  41
  42 #define RBD_DIRECTORY           "rbd_directory"
  43 #define RBD_INFO                "rbd_info"
  44
  45 #define RBD_DEFAULT_OBJ_ORDER   22   /* 4MB */
  46 #define RBD_MIN_OBJ_ORDER       16
  47 #define RBD_MAX_OBJ_ORDER       30
  48
  49 #define RBD_MAX_SEG_NAME_LEN    128
  50
  51 #define RBD_COMP_NONE           0
  52 #define RBD_CRYPT_NONE          0
  53
  54 #define RBD_HEADER_TEXT         "<<< Rados Block Device Image >>>\n"
  55 #define RBD_HEADER_SIGNATURE    "RBD"
  56 #define RBD_HEADER_VERSION      "001.005"
  57
  58 struct rbd_image_snap_ondisk {
  59         __le64 id;
  60         __le64 image_size;
  61 } __attribute__((packed));
  62
  63 struct rbd_image_header_ondisk {
  64         char text[40];
  65         char object_prefix[24];
  66         char signature[4];
  67         char version[8];
  68         struct {
  69                 __u8 order;
  70                 __u8 crypt_type;
  71                 __u8 comp_type;
  72                 __u8 unused;
  73         } __attribute__((packed)) options;
  74         __le64 image_size;
  75         __le64 snap_seq;
  76         __le32 snap_count;
  77         __le32 reserved;
  78         __le64 snap_names_len;
  79         struct rbd_image_snap_ondisk snaps[0];
  80 } __attribute__((packed));
  81
  82
  83 #endif