ceph/src/pmdk/src/libpmemblk/btt_layout.h

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2 /* Copyright 2014-2020, Intel Corporation */
   3
   4 /*
   5  * btt_layout.h -- block translation table on-media layout definitions
   6  */
   7
   8 /*
   9  * Layout of BTT info block.  All integers are stored little-endian.
  10  */
  11
  12 #ifndef BTT_LAYOUT_H
  13 #define BTT_LAYOUT_H 1
  14
  15 #ifdef __cplusplus
  16 extern "C" {
  17 #endif
  18
  19 #define BTT_ALIGNMENT ((uintptr_t)4096) /* alignment of all BTT structures */
  20 #define BTTINFO_SIG_LEN 16
  21 #define BTTINFO_UUID_LEN 16
  22 #define BTTINFO_UNUSED_LEN 3968
  23 #define BTTINFO_SIG             "BTT_ARENA_INFO\0"
  24
  25 struct btt_info {
  26         char sig[BTTINFO_SIG_LEN];      /* must be "BTT_ARENA_INFO\0\0" */
  27         uint8_t uuid[BTTINFO_UUID_LEN]; /* BTT UUID */
  28         uint8_t parent_uuid[BTTINFO_UUID_LEN];  /* UUID of container */
  29         uint32_t flags;                 /* see flag bits below */
  30         uint16_t major;                 /* major version */
  31         uint16_t minor;                 /* minor version */
  32         uint32_t external_lbasize;      /* advertised LBA size (bytes) */
  33         uint32_t external_nlba;         /* advertised LBAs in this arena */
  34         uint32_t internal_lbasize;      /* size of data area blocks (bytes) */
  35         uint32_t internal_nlba;         /* number of blocks in data area */
  36         uint32_t nfree;                 /* number of free blocks */
  37         uint32_t infosize;              /* size of this info block */
  38
  39         /*
  40          * The following offsets are relative to the beginning of
  41          * the btt_info block.
  42          */
  43         uint64_t nextoff;               /* offset to next arena (or zero) */
  44         uint64_t dataoff;               /* offset to arena data area */
  45         uint64_t mapoff;                /* offset to area map */
  46         uint64_t flogoff;               /* offset to area flog */
  47         uint64_t infooff;               /* offset to backup info block */
  48
  49         char unused[BTTINFO_UNUSED_LEN];        /* must be zero */
  50
  51         uint64_t checksum;              /* Fletcher64 of all fields */
  52 };
  53
  54 /*
  55  * Definitions for flags mask for btt_info structure above.
  56  */
  57 #define BTTINFO_FLAG_ERROR      0x00000001 /* error state (read-only) */
  58 #define BTTINFO_FLAG_ERROR_MASK 0x00000001 /* all error bits */
  59
  60 /*
  61  * Current on-media format versions.
  62  */
  63 #define BTTINFO_MAJOR_VERSION 1
  64 #define BTTINFO_MINOR_VERSION 1
  65
  66 /*
  67  * Layout of a BTT "flog" entry.  All integers are stored little-endian.
  68  *
  69  * The "nfree" field in the BTT info block determines how many of these
  70  * flog entries there are, and each entry consists of two of the following
  71  * structs (entry updates alternate between the two structs), padded up
  72  * to a cache line boundary to isolate adjacent updates.
  73  */
  74
  75 #define BTT_FLOG_PAIR_ALIGN ((uintptr_t)64)
  76
  77 struct btt_flog {
  78         uint32_t lba;           /* last pre-map LBA using this entry */
  79         uint32_t old_map;       /* old post-map LBA (the freed block) */
  80         uint32_t new_map;       /* new post-map LBA */
  81         uint32_t seq;           /* sequence number (01, 10, 11) */
  82 };
  83
  84 /*
  85  * Layout of a BTT "map" entry.  4-byte internal LBA offset, little-endian.
  86  */
  87 #define BTT_MAP_ENTRY_SIZE 4
  88 #define BTT_MAP_ENTRY_ERROR 0x40000000U
  89 #define BTT_MAP_ENTRY_ZERO 0x80000000U
  90 #define BTT_MAP_ENTRY_NORMAL 0xC0000000U
  91 #define BTT_MAP_ENTRY_LBA_MASK 0x3fffffffU
  92 #define BTT_MAP_LOCK_ALIGN ((uintptr_t)64)
  93
  94 /*
  95  * BTT layout properties...
  96  */
  97 #define BTT_MIN_SIZE ((1u << 20) * 16)
  98 #define BTT_MAX_ARENA (1ull << 39) /* 512GB per arena */
  99 #define BTT_MIN_LBA_SIZE (size_t)512
 100 #define BTT_INTERNAL_LBA_ALIGNMENT 256U
 101 #define BTT_DEFAULT_NFREE 256
 102
 103 #ifdef __cplusplus
 104 }
 105 #endif
 106
 107 #endif