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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 | /* SPDX-License-Identifier: GPL-2.0+ */ /* * Functions to convert BTRFS structures from disk to CPU endianness and back. * * 2017 Marek Behún, CZ.NIC, kabel@kernel.org */ #ifndef __BTRFS_CONV_FUNCS_H__ #define __BTRFS_CONV_FUNCS_H__ #include "ctree.h" #include <u-boot/variadic-macro.h> #include <asm/byteorder.h> /* We are using variadic macros and C11 _Generic to achieve compact code. We want to define macro DEFINE_CONV(x, ...), where the first argument is the name of the structure for which it shall define conversion functions (the names of the functions shall be x_to_cpu and x_to_disk), and the other arguments are names of the members on which the functions shall do endianness conversion. */ #if defined(__LITTLE_ENDIAN) /* If the target machine is little endian, the conversion functions do nothing, since the on disk format is little endian. */ # define DEFINE_CONV(n,...) \ static inline struct n *n##_to_disk(struct n * r) \ { \ return r; \ } \ static inline struct n *n##_to_cpu(struct n * r) \ { \ return r; \ } # define DEFINE_CONV_ALT(n,a,...) \ static inline struct n *n##_to_disk_##a(struct n * r) \ { \ return r; \ } \ static inline struct n *n##_to_cpu_##a(struct n * r) \ { \ return r; \ } #else /* !defined(__LITTLE_ENDIAN) */ /* Some structures contain not only scalar members, but compound types as well (for example, struct btrfs_inode_item contains members of type struct btrfs_timespec. For these members we want to call the conversion function recursively, so first we declare the functions taking pointers to this types (these function will be defined later by the DEFINE_CONV macro) and then we define correspond functions taking non-pointers, so that they can be used in the expansion of the _Generic. */ # define DEFINE_CONV_FOR_STRUCT(n) \ static inline struct n * n##_to_disk(struct n *); \ static inline struct n * n##_to_cpu(struct n *); \ static inline struct n n##_to_disk_v(struct n x) { \ return *n##_to_disk(&x); \ } \ static inline struct n n##_to_cpu_v(struct n x) { \ return *n##_to_cpu(&x); \ } DEFINE_CONV_FOR_STRUCT(btrfs_key) DEFINE_CONV_FOR_STRUCT(btrfs_stripe) DEFINE_CONV_FOR_STRUCT(btrfs_timespec) DEFINE_CONV_FOR_STRUCT(btrfs_inode_item) DEFINE_CONV_FOR_STRUCT(btrfs_root_backup) DEFINE_CONV_FOR_STRUCT(btrfs_dev_item) /* Now define the _Generic for both CPU to LE and LE to CPU */ # define DEFINE_CONV_CPU_TO_LE(x) \ (d->x) = _Generic((d->x), \ __u16: cpu_to_le16, \ __u32: cpu_to_le32, \ __u64: cpu_to_le64, \ struct btrfs_key: btrfs_key_to_disk_v, \ struct btrfs_stripe: btrfs_stripe_to_disk_v, \ struct btrfs_timespec: btrfs_timespec_to_disk_v, \ struct btrfs_inode_item: btrfs_inode_item_to_disk_v, \ struct btrfs_root_backup: btrfs_root_backup_to_disk_v, \ struct btrfs_dev_item: btrfs_dev_item_to_disk_v \ )((d->x)); # define DEFINE_CONV_LE_TO_CPU(x) \ (d->x) = _Generic((d->x), \ __u16: le16_to_cpu, \ __u32: le32_to_cpu, \ __u64: le64_to_cpu, \ struct btrfs_key: btrfs_key_to_cpu_v, \ struct btrfs_stripe: btrfs_stripe_to_cpu_v, \ struct btrfs_timespec: btrfs_timespec_to_cpu_v, \ struct btrfs_inode_item: btrfs_inode_item_to_cpu_v, \ struct btrfs_root_backup: btrfs_root_backup_to_cpu_v, \ struct btrfs_dev_item: btrfs_dev_item_to_cpu_v \ )((d->x)); # define DEFINE_CONV_ONE(t,n,m,...) \ static inline struct t * n(struct t * d) { \ CALL_MACRO_FOR_EACH(m, ##__VA_ARGS__) \ return d; \ } /* Finally define the DEFINE_CONV macro */ # define DEFINE_CONV(n,...) \ DEFINE_CONV_ONE(n,n##_to_disk,DEFINE_CONV_CPU_TO_LE,##__VA_ARGS__) \ DEFINE_CONV_ONE(n,n##_to_cpu,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__) # define DEFINE_CONV_ALT(n,a,...) \ DEFINE_CONV_ONE(n,n##_to_disk_##a,DEFINE_CONV_CPU_TO_LE, \ ##__VA_ARGS__) \ DEFINE_CONV_ONE(n,n##_to_cpu_##a,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__) #endif /* !defined(__LITTLE_ENDIAN) */ DEFINE_CONV(btrfs_key, objectid, offset) DEFINE_CONV(btrfs_dev_item, devid, total_bytes, bytes_used, io_align, io_width, sector_size, type, generation, start_offset, dev_group) DEFINE_CONV(btrfs_stripe, devid, offset) DEFINE_CONV(btrfs_chunk, length, owner, stripe_len, type, io_align, io_width, sector_size, num_stripes, sub_stripes) DEFINE_CONV(btrfs_free_space_entry, offset, bytes) DEFINE_CONV(btrfs_free_space_header, location, generation, num_entries, num_bitmaps) DEFINE_CONV(btrfs_extent_item, refs, generation, flags) DEFINE_CONV(btrfs_tree_block_info, key) DEFINE_CONV(btrfs_extent_data_ref, root, objectid, offset, count) DEFINE_CONV(btrfs_shared_data_ref, count) DEFINE_CONV(btrfs_extent_inline_ref, offset) DEFINE_CONV(btrfs_dev_extent, chunk_tree, chunk_objectid, chunk_offset, length) DEFINE_CONV(btrfs_inode_ref, index, name_len) DEFINE_CONV(btrfs_inode_extref, parent_objectid, index, name_len) DEFINE_CONV(btrfs_timespec, sec, nsec) DEFINE_CONV(btrfs_inode_item, generation, transid, size, nbytes, block_group, nlink, uid, gid, mode, rdev, flags, sequence, atime, ctime, mtime, otime) DEFINE_CONV(btrfs_dir_log_item, end) DEFINE_CONV(btrfs_dir_item, location, transid, data_len, name_len) DEFINE_CONV(btrfs_root_item, inode, generation, root_dirid, bytenr, byte_limit, bytes_used, last_snapshot, flags, refs, drop_progress, generation_v2, ctransid, otransid, stransid, rtransid, ctime, otime, stime, rtime) DEFINE_CONV(btrfs_root_ref, dirid, sequence, name_len) DEFINE_CONV(btrfs_file_extent_item, generation, ram_bytes, other_encoding, disk_bytenr, disk_num_bytes, offset, num_bytes) DEFINE_CONV_ALT(btrfs_file_extent_item, inl, generation, ram_bytes, other_encoding) DEFINE_CONV(btrfs_dev_replace_item, src_devid, cursor_left, cursor_right, cont_reading_from_srcdev_mode, replace_state, time_started, time_stopped, num_write_errors, num_uncorrectable_read_errors) DEFINE_CONV(btrfs_block_group_item, used, chunk_objectid, flags) DEFINE_CONV(btrfs_free_space_info, extent_count, flags) DEFINE_CONV(btrfs_header, bytenr, flags, generation, owner, nritems) DEFINE_CONV(btrfs_root_backup, tree_root, tree_root_gen, chunk_root, chunk_root_gen, extent_root, extent_root_gen, fs_root, fs_root_gen, dev_root, dev_root_gen, csum_root, csum_root_gen, total_bytes, bytes_used, num_devices) DEFINE_CONV(btrfs_super_block, bytenr, flags, magic, generation, root, chunk_root, log_root, log_root_transid, total_bytes, bytes_used, root_dir_objectid, num_devices, sectorsize, nodesize, __unused_leafsize, stripesize, sys_chunk_array_size, chunk_root_generation, compat_flags, compat_ro_flags, incompat_flags, csum_type, dev_item, cache_generation, uuid_tree_generation, super_roots[0], super_roots[1], super_roots[2], super_roots[3]) DEFINE_CONV(btrfs_item, key, offset, size) DEFINE_CONV(btrfs_key_ptr, key, blockptr, generation) #endif /* __BTRFS_CONV_FUNCS_H__ */ |