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/*
* Copyright 2014-2017, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* btt_layout.h -- block translation table on-media layout definitions
*/
/*
* Layout of BTT info block. All integers are stored little-endian.
*/
#define BTT_ALIGNMENT ((uintptr_t)4096) /* alignment of all BTT structures */
#define BTTINFO_SIG_LEN 16
#define BTTINFO_UUID_LEN 16
#define BTTINFO_UNUSED_LEN 3968
#define BTTINFO_SIG "BTT_ARENA_INFO\0"
struct btt_info {
char sig[BTTINFO_SIG_LEN]; /* must be "BTT_ARENA_INFO\0\0" */
uint8_t uuid[BTTINFO_UUID_LEN]; /* BTT UUID */
uint8_t parent_uuid[BTTINFO_UUID_LEN]; /* UUID of container */
uint32_t flags; /* see flag bits below */
uint16_t major; /* major version */
uint16_t minor; /* minor version */
uint32_t external_lbasize; /* advertised LBA size (bytes) */
uint32_t external_nlba; /* advertised LBAs in this arena */
uint32_t internal_lbasize; /* size of data area blocks (bytes) */
uint32_t internal_nlba; /* number of blocks in data area */
uint32_t nfree; /* number of free blocks */
uint32_t infosize; /* size of this info block */
/*
* The following offsets are relative to the beginning of
* the btt_info block.
*/
uint64_t nextoff; /* offset to next arena (or zero) */
uint64_t dataoff; /* offset to arena data area */
uint64_t mapoff; /* offset to area map */
uint64_t flogoff; /* offset to area flog */
uint64_t infooff; /* offset to backup info block */
char unused[BTTINFO_UNUSED_LEN]; /* must be zero */
uint64_t checksum; /* Fletcher64 of all fields */
};
/*
* Definitions for flags mask for btt_info structure above.
*/
#define BTTINFO_FLAG_ERROR 0x00000001 /* error state (read-only) */
#define BTTINFO_FLAG_ERROR_MASK 0x00000001 /* all error bits */
/*
* Current on-media format versions.
*/
#define BTTINFO_MAJOR_VERSION 1
#define BTTINFO_MINOR_VERSION 1
/*
* Layout of a BTT "flog" entry. All integers are stored little-endian.
*
* The "nfree" field in the BTT info block determines how many of these
* flog entries there are, and each entry consists of two of the following
* structs (entry updates alternate between the two structs), padded up
* to a cache line boundary to isolate adjacent updates.
*/
#define BTT_FLOG_PAIR_ALIGN ((uintptr_t)64)
struct btt_flog {
uint32_t lba; /* last pre-map LBA using this entry */
uint32_t old_map; /* old post-map LBA (the freed block) */
uint32_t new_map; /* new post-map LBA */
uint32_t seq; /* sequence number (01, 10, 11) */
};
/*
* Layout of a BTT "map" entry. 4-byte internal LBA offset, little-endian.
*/
#define BTT_MAP_ENTRY_SIZE 4
#define BTT_MAP_ENTRY_ERROR 0x40000000U
#define BTT_MAP_ENTRY_ZERO 0x80000000U
#define BTT_MAP_ENTRY_NORMAL 0xC0000000U
#define BTT_MAP_ENTRY_LBA_MASK 0x3fffffffU
#define BTT_MAP_LOCK_ALIGN ((uintptr_t)64)
/*
* BTT layout properties...
*/
#define BTT_MIN_SIZE ((1u << 20) * 16)
#define BTT_MAX_ARENA (1ull << 39) /* 512GB per arena */
#define BTT_MIN_LBA_SIZE (size_t)512
#define BTT_INTERNAL_LBA_ALIGNMENT 256U
#define BTT_DEFAULT_NFREE 256