1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Functions to convert BTRFS structures from disk to CPU endianness and back. 4 * 5 * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz 6 */ 7 8 #ifndef __BTRFS_CONV_FUNCS_H__ 9 #define __BTRFS_CONV_FUNCS_H__ 10 11 #include "ctree.h" 12 #include <u-boot/variadic-macro.h> 13 #include <asm/byteorder.h> 14 15 /* We are using variadic macros and C11 _Generic to achieve compact code. 16 17 We want to define macro DEFINE_CONV(x, ...), where the first argument is the 18 name of the structure for which it shall define conversion functions (the 19 names of the functions shall be x_to_cpu and x_to_disk), and the other 20 arguments are names of the members on which the functions shall do 21 endianness conversion. */ 22 23 #if defined(__LITTLE_ENDIAN) 24 25 /* If the target machine is little endian, the conversion functions do 26 nothing, since the on disk format is little endian. */ 27 28 # define DEFINE_CONV(n,...) \ 29 static inline struct n *n##_to_disk(struct n * r) \ 30 { \ 31 return r; \ 32 } \ 33 static inline struct n *n##_to_cpu(struct n * r) \ 34 { \ 35 return r; \ 36 } 37 38 # define DEFINE_CONV_ALT(n,a,...) \ 39 static inline struct n *n##_to_disk_##a(struct n * r) \ 40 { \ 41 return r; \ 42 } \ 43 static inline struct n *n##_to_cpu_##a(struct n * r) \ 44 { \ 45 return r; \ 46 } 47 48 #else /* !defined(__LITTLE_ENDIAN) */ 49 50 /* Some structures contain not only scalar members, but compound types as well 51 (for example, struct btrfs_inode_item contains members of type struct 52 btrfs_timespec. 53 54 For these members we want to call the conversion function recursively, so 55 first we declare the functions taking pointers to this types (these function 56 will be defined later by the DEFINE_CONV macro) and then we define 57 correspond functions taking non-pointers, so that they can be used in the 58 expansion of the _Generic. */ 59 # define DEFINE_CONV_FOR_STRUCT(n) \ 60 static inline struct n * n##_to_disk(struct n *); \ 61 static inline struct n * n##_to_cpu(struct n *); \ 62 static inline struct n n##_to_disk_v(struct n x) { \ 63 return *n##_to_disk(&x); \ 64 } \ 65 static inline struct n n##_to_cpu_v(struct n x) { \ 66 return *n##_to_cpu(&x); \ 67 } 68 69 DEFINE_CONV_FOR_STRUCT(btrfs_key) 70 DEFINE_CONV_FOR_STRUCT(btrfs_stripe) 71 DEFINE_CONV_FOR_STRUCT(btrfs_timespec) 72 DEFINE_CONV_FOR_STRUCT(btrfs_inode_item) 73 DEFINE_CONV_FOR_STRUCT(btrfs_root_backup) 74 DEFINE_CONV_FOR_STRUCT(btrfs_dev_item) 75 76 /* Now define the _Generic for both CPU to LE and LE to CPU */ 77 # define DEFINE_CONV_CPU_TO_LE(x) \ 78 (d->x) = _Generic((d->x), \ 79 __u16: cpu_to_le16, \ 80 __u32: cpu_to_le32, \ 81 __u64: cpu_to_le64, \ 82 struct btrfs_key: btrfs_key_to_disk_v, \ 83 struct btrfs_stripe: btrfs_stripe_to_disk_v, \ 84 struct btrfs_timespec: btrfs_timespec_to_disk_v, \ 85 struct btrfs_inode_item: btrfs_inode_item_to_disk_v, \ 86 struct btrfs_root_backup: btrfs_root_backup_to_disk_v, \ 87 struct btrfs_dev_item: btrfs_dev_item_to_disk_v \ 88 )((d->x)); 89 90 # define DEFINE_CONV_LE_TO_CPU(x) \ 91 (d->x) = _Generic((d->x), \ 92 __u16: le16_to_cpu, \ 93 __u32: le32_to_cpu, \ 94 __u64: le64_to_cpu, \ 95 struct btrfs_key: btrfs_key_to_cpu_v, \ 96 struct btrfs_stripe: btrfs_stripe_to_cpu_v, \ 97 struct btrfs_timespec: btrfs_timespec_to_cpu_v, \ 98 struct btrfs_inode_item: btrfs_inode_item_to_cpu_v, \ 99 struct btrfs_root_backup: btrfs_root_backup_to_cpu_v, \ 100 struct btrfs_dev_item: btrfs_dev_item_to_cpu_v \ 101 )((d->x)); 102 103 # define DEFINE_CONV_ONE(t,n,m,...) \ 104 static inline struct t * n(struct t * d) { \ 105 CALL_MACRO_FOR_EACH(m, ##__VA_ARGS__) \ 106 return d; \ 107 } 108 109 /* Finally define the DEFINE_CONV macro */ 110 # define DEFINE_CONV(n,...) \ 111 DEFINE_CONV_ONE(n,n##_to_disk,DEFINE_CONV_CPU_TO_LE,##__VA_ARGS__) \ 112 DEFINE_CONV_ONE(n,n##_to_cpu,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__) 113 114 # define DEFINE_CONV_ALT(n,a,...) \ 115 DEFINE_CONV_ONE(n,n##_to_disk_##a,DEFINE_CONV_CPU_TO_LE, \ 116 ##__VA_ARGS__) \ 117 DEFINE_CONV_ONE(n,n##_to_cpu_##a,DEFINE_CONV_LE_TO_CPU,##__VA_ARGS__) 118 119 #endif /* !defined(__LITTLE_ENDIAN) */ 120 121 DEFINE_CONV(btrfs_key, objectid, offset) 122 DEFINE_CONV(btrfs_dev_item, devid, total_bytes, bytes_used, io_align, io_width, 123 sector_size, type, generation, start_offset, dev_group) 124 DEFINE_CONV(btrfs_stripe, devid, offset) 125 DEFINE_CONV(btrfs_chunk, length, owner, stripe_len, type, io_align, io_width, 126 sector_size, num_stripes, sub_stripes) 127 DEFINE_CONV(btrfs_free_space_entry, offset, bytes) 128 DEFINE_CONV(btrfs_free_space_header, location, generation, num_entries, 129 num_bitmaps) 130 DEFINE_CONV(btrfs_extent_item, refs, generation, flags) 131 DEFINE_CONV(btrfs_tree_block_info, key) 132 DEFINE_CONV(btrfs_extent_data_ref, root, objectid, offset, count) 133 DEFINE_CONV(btrfs_shared_data_ref, count) 134 DEFINE_CONV(btrfs_extent_inline_ref, offset) 135 DEFINE_CONV(btrfs_dev_extent, chunk_tree, chunk_objectid, chunk_offset, length) 136 DEFINE_CONV(btrfs_inode_ref, index, name_len) 137 DEFINE_CONV(btrfs_inode_extref, parent_objectid, index, name_len) 138 DEFINE_CONV(btrfs_timespec, sec, nsec) 139 DEFINE_CONV(btrfs_inode_item, generation, transid, size, nbytes, block_group, 140 nlink, uid, gid, mode, rdev, flags, sequence, atime, ctime, mtime, 141 otime) 142 DEFINE_CONV(btrfs_dir_log_item, end) 143 DEFINE_CONV(btrfs_dir_item, location, transid, data_len, name_len) 144 DEFINE_CONV(btrfs_root_item, inode, generation, root_dirid, bytenr, byte_limit, 145 bytes_used, last_snapshot, flags, refs, drop_progress, 146 generation_v2, ctransid, otransid, stransid, rtransid, ctime, 147 otime, stime, rtime) 148 DEFINE_CONV(btrfs_root_ref, dirid, sequence, name_len) 149 DEFINE_CONV(btrfs_file_extent_item, generation, ram_bytes, other_encoding, 150 disk_bytenr, disk_num_bytes, offset, num_bytes) 151 DEFINE_CONV_ALT(btrfs_file_extent_item, inl, generation, ram_bytes, 152 other_encoding) 153 DEFINE_CONV(btrfs_dev_replace_item, src_devid, cursor_left, cursor_right, 154 cont_reading_from_srcdev_mode, replace_state, time_started, 155 time_stopped, num_write_errors, num_uncorrectable_read_errors) 156 DEFINE_CONV(btrfs_block_group_item, used, chunk_objectid, flags) 157 DEFINE_CONV(btrfs_free_space_info, extent_count, flags) 158 159 DEFINE_CONV(btrfs_header, bytenr, flags, generation, owner, nritems) 160 DEFINE_CONV(btrfs_root_backup, tree_root, tree_root_gen, chunk_root, 161 chunk_root_gen, extent_root, extent_root_gen, fs_root, fs_root_gen, 162 dev_root, dev_root_gen, csum_root, csum_root_gen, total_bytes, 163 bytes_used, num_devices) 164 DEFINE_CONV(btrfs_super_block, bytenr, flags, magic, generation, root, 165 chunk_root, log_root, log_root_transid, total_bytes, bytes_used, 166 root_dir_objectid, num_devices, sectorsize, nodesize, 167 __unused_leafsize, stripesize, sys_chunk_array_size, 168 chunk_root_generation, compat_flags, compat_ro_flags, 169 incompat_flags, csum_type, dev_item, cache_generation, 170 uuid_tree_generation, super_roots[0], super_roots[1], 171 super_roots[2], super_roots[3]) 172 DEFINE_CONV(btrfs_item, key, offset, size) 173 DEFINE_CONV(btrfs_key_ptr, key, blockptr, generation) 174 175 #endif /* __BTRFS_CONV_FUNCS_H__ */ 176