177 lines
6.9 KiB
C
177 lines
6.9 KiB
C
/*
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* Functions to convert BTRFS structures from disk to CPU endianness and back.
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*
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* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef __BTRFS_CONV_FUNCS_H__
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#define __BTRFS_CONV_FUNCS_H__
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#include "ctree.h"
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#include <u-boot/variadic-macro.h>
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#include <asm/byteorder.h>
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/* We are using variadic macros and C11 _Generic to achieve compact code.
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We want to define macro DEFINE_CONV(x, ...), where the first argument is the
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name of the structure for which it shall define conversion functions (the
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names of the functions shall be x_to_cpu and x_to_disk), and the other
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arguments are names of the members on which the functions shall do
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endianness conversion. */
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#if defined(__LITTLE_ENDIAN)
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/* If the target machine is little endian, the conversion functions do
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nothing, since the on disk format is little endian. */
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# define DEFINE_CONV(n,...) \
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static inline struct n *n##_to_disk(struct n * r) \
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{ \
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return r; \
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} \
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static inline struct n *n##_to_cpu(struct n * r) \
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{ \
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return r; \
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}
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# define DEFINE_CONV_ALT(n,a,...) \
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static inline struct n *n##_to_disk_##a(struct n * r) \
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{ \
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return r; \
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} \
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static inline struct n *n##_to_cpu_##a(struct n * r) \
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{ \
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return r; \
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}
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#else /* !defined(__LITTLE_ENDIAN) */
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/* Some structures contain not only scalar members, but compound types as well
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(for example, struct btrfs_inode_item contains members of type struct
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btrfs_timespec.
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For these members we want to call the conversion function recursively, so
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first we declare the functions taking pointers to this types (these function
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will be defined later by the DEFINE_CONV macro) and then we define
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correspond functions taking non-pointers, so that they can be used in the
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expansion of the _Generic. */
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# define DEFINE_CONV_FOR_STRUCT(n) \
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static inline struct n * n##_to_disk(struct n *); \
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static inline struct n * n##_to_cpu(struct n *); \
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static inline struct n n##_to_disk_v(struct n x) { \
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return *n##_to_disk(&x); \
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} \
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static inline struct n n##_to_cpu_v(struct n x) { \
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return *n##_to_cpu(&x); \
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}
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DEFINE_CONV_FOR_STRUCT(btrfs_key)
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DEFINE_CONV_FOR_STRUCT(btrfs_stripe)
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DEFINE_CONV_FOR_STRUCT(btrfs_timespec)
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DEFINE_CONV_FOR_STRUCT(btrfs_inode_item)
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DEFINE_CONV_FOR_STRUCT(btrfs_root_backup)
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DEFINE_CONV_FOR_STRUCT(btrfs_dev_item)
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/* Now define the _Generic for both CPU to LE and LE to CPU */
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# define DEFINE_CONV_CPU_TO_LE(x) \
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(d->x) = _Generic((d->x), \
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__u16: cpu_to_le16, \
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__u32: cpu_to_le32, \
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__u64: cpu_to_le64, \
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struct btrfs_key: btrfs_key_to_disk_v, \
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struct btrfs_stripe: btrfs_stripe_to_disk_v, \
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struct btrfs_timespec: btrfs_timespec_to_disk_v, \
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struct btrfs_inode_item: btrfs_inode_item_to_disk_v, \
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struct btrfs_root_backup: btrfs_root_backup_to_disk_v, \
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struct btrfs_dev_item: btrfs_dev_item_to_disk_v \
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)((d->x));
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# define DEFINE_CONV_LE_TO_CPU(x) \
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(d->x) = _Generic((d->x), \
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__u16: le16_to_cpu, \
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__u32: le32_to_cpu, \
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__u64: le64_to_cpu, \
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struct btrfs_key: btrfs_key_to_cpu_v, \
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struct btrfs_stripe: btrfs_stripe_to_cpu_v, \
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struct btrfs_timespec: btrfs_timespec_to_cpu_v, \
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struct btrfs_inode_item: btrfs_inode_item_to_cpu_v, \
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struct btrfs_root_backup: btrfs_root_backup_to_cpu_v, \
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struct btrfs_dev_item: btrfs_dev_item_to_cpu_v \
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)((d->x));
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# define DEFINE_CONV_ONE(t,n,m,...) \
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static inline struct t * n(struct t * d) { \
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CALL_MACRO_FOR_EACH(m, ##__VA_ARGS__) \
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return d; \
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}
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/* Finally define the DEFINE_CONV macro */
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# define DEFINE_CONV(n,...) \
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DEFINE_CONV_ONE(n,n##_to_disk,DEFINE_CONV_CPU_TO_LE,##__VA_ARGS__) \
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DEFINE_CONV_ONE(n,n##_to_cpu,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__)
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# define DEFINE_CONV_ALT(n,a,...) \
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DEFINE_CONV_ONE(n,n##_to_disk_##a,DEFINE_CONV_CPU_TO_LE, \
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##__VA_ARGS__) \
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DEFINE_CONV_ONE(n,n##_to_cpu_##a,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__)
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#endif /* !defined(__LITTLE_ENDIAN) */
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DEFINE_CONV(btrfs_key, objectid, offset)
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DEFINE_CONV(btrfs_dev_item, devid, total_bytes, bytes_used, io_align, io_width,
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sector_size, type, generation, start_offset, dev_group)
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DEFINE_CONV(btrfs_stripe, devid, offset)
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DEFINE_CONV(btrfs_chunk, length, owner, stripe_len, type, io_align, io_width,
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sector_size, num_stripes, sub_stripes)
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DEFINE_CONV(btrfs_free_space_entry, offset, bytes)
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DEFINE_CONV(btrfs_free_space_header, location, generation, num_entries,
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num_bitmaps)
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DEFINE_CONV(btrfs_extent_item, refs, generation, flags)
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DEFINE_CONV(btrfs_tree_block_info, key)
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DEFINE_CONV(btrfs_extent_data_ref, root, objectid, offset, count)
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DEFINE_CONV(btrfs_shared_data_ref, count)
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DEFINE_CONV(btrfs_extent_inline_ref, offset)
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DEFINE_CONV(btrfs_dev_extent, chunk_tree, chunk_objectid, chunk_offset, length)
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DEFINE_CONV(btrfs_inode_ref, index, name_len)
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DEFINE_CONV(btrfs_inode_extref, parent_objectid, index, name_len)
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DEFINE_CONV(btrfs_timespec, sec, nsec)
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DEFINE_CONV(btrfs_inode_item, generation, transid, size, nbytes, block_group,
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nlink, uid, gid, mode, rdev, flags, sequence, atime, ctime, mtime,
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otime)
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DEFINE_CONV(btrfs_dir_log_item, end)
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DEFINE_CONV(btrfs_dir_item, location, transid, data_len, name_len)
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DEFINE_CONV(btrfs_root_item, inode, generation, root_dirid, bytenr, byte_limit,
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bytes_used, last_snapshot, flags, refs, drop_progress,
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generation_v2, ctransid, otransid, stransid, rtransid, ctime,
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otime, stime, rtime)
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DEFINE_CONV(btrfs_root_ref, dirid, sequence, name_len)
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DEFINE_CONV(btrfs_file_extent_item, generation, ram_bytes, other_encoding,
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disk_bytenr, disk_num_bytes, offset, num_bytes)
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DEFINE_CONV_ALT(btrfs_file_extent_item, inl, generation, ram_bytes,
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other_encoding)
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DEFINE_CONV(btrfs_dev_replace_item, src_devid, cursor_left, cursor_right,
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cont_reading_from_srcdev_mode, replace_state, time_started,
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time_stopped, num_write_errors, num_uncorrectable_read_errors)
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DEFINE_CONV(btrfs_block_group_item, used, chunk_objectid, flags)
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DEFINE_CONV(btrfs_free_space_info, extent_count, flags)
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DEFINE_CONV(btrfs_header, bytenr, flags, generation, owner, nritems)
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DEFINE_CONV(btrfs_root_backup, tree_root, tree_root_gen, chunk_root,
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chunk_root_gen, extent_root, extent_root_gen, fs_root, fs_root_gen,
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dev_root, dev_root_gen, csum_root, csum_root_gen, total_bytes,
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bytes_used, num_devices)
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DEFINE_CONV(btrfs_super_block, bytenr, flags, magic, generation, root,
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chunk_root, log_root, log_root_transid, total_bytes, bytes_used,
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root_dir_objectid, num_devices, sectorsize, nodesize,
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__unused_leafsize, stripesize, sys_chunk_array_size,
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chunk_root_generation, compat_flags, compat_ro_flags,
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incompat_flags, csum_type, dev_item, cache_generation,
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uuid_tree_generation, super_roots[0], super_roots[1],
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super_roots[2], super_roots[3])
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DEFINE_CONV(btrfs_item, key, offset, size)
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DEFINE_CONV(btrfs_key_ptr, key, blockptr, generation)
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#endif /* __BTRFS_CONV_FUNCS_H__ */
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