/* SPDX-License-Identifier: GPL-2.0-only */ /* * Block Translation Table library * Copyright (c) 2014-2015, Intel Corporation. */ #ifndef _LINUX_BTT_H #define _LINUX_BTT_H #include <linux/types.h> #define BTT_SIG_LEN 16 #define BTT_SIG "BTT_ARENA_INFO\0" #define MAP_ENT_SIZE 4 #define MAP_TRIM_SHIFT 31 #define MAP_TRIM_MASK (1 << MAP_TRIM_SHIFT) #define MAP_ERR_SHIFT 30 #define MAP_ERR_MASK (1 << MAP_ERR_SHIFT) #define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT))) #define MAP_ENT_NORMAL 0xC0000000 #define LOG_GRP_SIZE sizeof(struct log_group) #define LOG_ENT_SIZE sizeof(struct log_entry) #define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */ #define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */ #define RTT_VALID (1UL << 31) #define RTT_INVALID 0 #define BTT_PG_SIZE 4096 #define BTT_DEFAULT_NFREE ND_MAX_LANES #define LOG_SEQ_INIT 1 #define IB_FLAG_ERROR 0x00000001 #define IB_FLAG_ERROR_MASK 0x00000001 #define ent_lba(ent) (ent & MAP_LBA_MASK) #define ent_e_flag(ent) (!!(ent & MAP_ERR_MASK)) #define ent_z_flag(ent) (!!(ent & MAP_TRIM_MASK)) #define set_e_flag(ent) (ent |= MAP_ERR_MASK) /* 'normal' is both e and z flags set */ #define ent_normal(ent) (ent_e_flag(ent) && ent_z_flag(ent)) enum btt_init_state { INIT_UNCHECKED = 0, INIT_NOTFOUND, INIT_READY }; /* * A log group represents one log 'lane', and consists of four log entries. * Two of the four entries are valid entries, and the remaining two are * padding. Due to an old bug in the padding location, we need to perform a * test to determine the padding scheme being used, and use that scheme * thereafter. * * In kernels prior to 4.15, 'log group' would have actual log entries at * indices (0, 2) and padding at indices (1, 3), where as the correct/updated * format has log entries at indices (0, 1) and padding at indices (2, 3). * * Old (pre 4.15) format: * +-----------------+-----------------+ * | ent[0] | ent[1] | * | 16B | 16B | * | lba/old/new/seq | pad | * +-----------------------------------+ * | ent[2] | ent[3] | * | 16B | 16B | * | lba/old/new/seq | pad | * +-----------------+-----------------+ * * New format: * +-----------------+-----------------+ * | ent[0] | ent[1] | * | 16B | 16B | * | lba/old/new/seq | lba/old/new/seq | * +-----------------------------------+ * | ent[2] | ent[3] | * | 16B | 16B | * | pad | pad | * +-----------------+-----------------+ * * We detect during start-up which format is in use, and set * arena->log_index[(0, 1)] with the detected format. */ struct log_entry { __le32 lba; __le32 old_map; __le32 new_map; __le32 seq; }; struct log_group { struct log_entry ent[4]; }; struct btt_sb { u8 signature[BTT_SIG_LEN]; u8 uuid[16]; u8 parent_uuid[16]; __le32 flags; __le16 version_major; __le16 version_minor; __le32 external_lbasize; __le32 external_nlba; __le32 internal_lbasize; __le32 internal_nlba; __le32 nfree; __le32 infosize; __le64 nextoff; __le64 dataoff; __le64 mapoff; __le64 logoff; __le64 info2off; u8 padding[3968]; __le64 checksum; }; struct free_entry { u32 block; u8 sub; u8 seq; u8 has_err; }; struct aligned_lock { union { spinlock_t lock; u8 cacheline_padding[L1_CACHE_BYTES]; }; }; /** * struct arena_info - handle for an arena * @size: Size in bytes this arena occupies on the raw device. * This includes arena metadata. * @external_lba_start: The first external LBA in this arena. * @internal_nlba: Number of internal blocks available in the arena * including nfree reserved blocks * @internal_lbasize: Internal and external lba sizes may be different as * we can round up 'odd' external lbasizes such as 520B * to be aligned. * @external_nlba: Number of blocks contributed by the arena to the number * reported to upper layers. (internal_nlba - nfree) * @external_lbasize: LBA size as exposed to upper layers. * @nfree: A reserve number of 'free' blocks that is used to * handle incoming writes. * @version_major: Metadata layout version major. * @version_minor: Metadata layout version minor. * @sector_size: The Linux sector size - 512 or 4096 * @nextoff: Offset in bytes to the start of the next arena. * @infooff: Offset in bytes to the info block of this arena. * @dataoff: Offset in bytes to the data area of this arena. * @mapoff: Offset in bytes to the map area of this arena. * @logoff: Offset in bytes to the log area of this arena. * @info2off: Offset in bytes to the backup info block of this arena. * @freelist: Pointer to in-memory list of free blocks * @rtt: Pointer to in-memory "Read Tracking Table" * @map_locks: Spinlocks protecting concurrent map writes * @nd_btt: Pointer to parent nd_btt structure. * @list: List head for list of arenas * @debugfs_dir: Debugfs dentry * @flags: Arena flags - may signify error states. * @err_lock: Mutex for synchronizing error clearing. * @log_index: Indices of the valid log entries in a log_group * * arena_info is a per-arena handle. Once an arena is narrowed down for an * IO, this struct is passed around for the duration of the IO. */ struct arena_info { u64 size; /* Total bytes for this arena */ u64 external_lba_start; u32 internal_nlba; u32 internal_lbasize; u32 external_nlba; u32 external_lbasize; u32 nfree; u16 version_major; u16 version_minor; u32 sector_size; /* Byte offsets to the different on-media structures */ u64 nextoff; u64 infooff; u64 dataoff; u64 mapoff; u64 logoff; u64 info2off; /* Pointers to other in-memory structures for this arena */ struct free_entry *freelist; u32 *rtt; struct aligned_lock *map_locks; struct nd_btt *nd_btt; struct list_head list; struct dentry *debugfs_dir; /* Arena flags */ u32 flags; struct mutex err_lock; int log_index[2]; }; struct badblocks; /** * struct btt - handle for a BTT instance * @btt_disk: Pointer to the gendisk for BTT device * @arena_list: Head of the list of arenas * @debugfs_dir: Debugfs dentry * @nd_btt: Parent nd_btt struct * @nlba: Number of logical blocks exposed to the upper layers * after removing the amount of space needed by metadata * @rawsize: Total size in bytes of the available backing device * @lbasize: LBA size as requested and presented to upper layers. * This is sector_size + size of any metadata. * @sector_size: The Linux sector size - 512 or 4096 * @lanes: Per-lane spinlocks * @init_lock: Mutex used for the BTT initialization * @init_state: Flag describing the initialization state for the BTT * @num_arenas: Number of arenas in the BTT instance * @phys_bb: Pointer to the namespace's badblocks structure */ struct btt { struct gendisk *btt_disk; struct list_head arena_list; struct dentry *debugfs_dir; struct nd_btt *nd_btt; u64 nlba; unsigned long long rawsize; u32 lbasize; u32 sector_size; struct nd_region *nd_region; struct mutex init_lock; int init_state; int num_arenas; struct badblocks *phys_bb; }; bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, struct btt_sb *btt_sb); #endif
