| Marek Behún | 2938754 | 2017-09-03 17:00:28 +0200 | [diff] [blame] | 1 | /* |
| 2 | * BTRFS filesystem implementation for U-Boot |
| 3 | * |
| 4 | * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz |
| 5 | * |
| 6 | * SPDX-License-Identifier: GPL-2.0+ |
| 7 | */ |
| 8 | |
| 9 | #include "btrfs.h" |
| 10 | #include <malloc.h> |
| 11 | |
| 12 | u64 btrfs_read_extent_inline(struct btrfs_path *path, |
| 13 | struct btrfs_file_extent_item *extent, u64 offset, |
| 14 | u64 size, char *out) |
| 15 | { |
| 16 | u32 clen, dlen, orig_size = size, res; |
| 17 | const char *cbuf; |
| 18 | char *dbuf; |
| 19 | const int data_off = offsetof(struct btrfs_file_extent_item, |
| 20 | disk_bytenr); |
| 21 | |
| 22 | clen = btrfs_path_item_size(path) - data_off; |
| 23 | cbuf = (const char *) extent + data_off; |
| 24 | dlen = extent->ram_bytes; |
| 25 | |
| 26 | if (offset > dlen) |
| 27 | return -1ULL; |
| 28 | |
| 29 | if (size > dlen - offset) |
| 30 | size = dlen - offset; |
| 31 | |
| 32 | if (extent->compression == BTRFS_COMPRESS_NONE) { |
| 33 | memcpy(out, cbuf + offset, size); |
| 34 | return size; |
| 35 | } |
| 36 | |
| 37 | if (dlen > orig_size) { |
| 38 | dbuf = malloc(dlen); |
| 39 | if (!dbuf) |
| 40 | return -1ULL; |
| 41 | } else { |
| 42 | dbuf = out; |
| 43 | } |
| 44 | |
| 45 | res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen); |
| 46 | if (res == -1 || res != dlen) |
| 47 | goto err; |
| 48 | |
| 49 | if (dlen > orig_size) { |
| 50 | memcpy(out, dbuf + offset, size); |
| 51 | free(dbuf); |
| 52 | } else if (offset) { |
| 53 | memmove(out, dbuf + offset, size); |
| 54 | } |
| 55 | |
| 56 | return size; |
| 57 | |
| 58 | err: |
| 59 | if (dlen > orig_size) |
| 60 | free(dbuf); |
| 61 | return -1ULL; |
| 62 | } |
| 63 | |
| 64 | u64 btrfs_read_extent_reg(struct btrfs_path *path, |
| 65 | struct btrfs_file_extent_item *extent, u64 offset, |
| 66 | u64 size, char *out) |
| 67 | { |
| 68 | u64 physical, clen, dlen, orig_size = size; |
| 69 | u32 res; |
| 70 | char *cbuf, *dbuf; |
| 71 | |
| 72 | clen = extent->disk_num_bytes; |
| 73 | dlen = extent->num_bytes; |
| 74 | |
| 75 | if (offset > dlen) |
| 76 | return -1ULL; |
| 77 | |
| 78 | if (size > dlen - offset) |
| 79 | size = dlen - offset; |
| 80 | |
| 81 | physical = btrfs_map_logical_to_physical(extent->disk_bytenr); |
| 82 | if (physical == -1ULL) |
| 83 | return -1ULL; |
| 84 | |
| 85 | if (extent->compression == BTRFS_COMPRESS_NONE) { |
| 86 | physical += extent->offset + offset; |
| 87 | if (!btrfs_devread(physical, size, out)) |
| 88 | return -1ULL; |
| 89 | |
| 90 | return size; |
| 91 | } |
| 92 | |
| 93 | cbuf = malloc(dlen > size ? clen + dlen : clen); |
| 94 | if (!cbuf) |
| 95 | return -1ULL; |
| 96 | |
| 97 | if (dlen > orig_size) |
| 98 | dbuf = cbuf + clen; |
| 99 | else |
| 100 | dbuf = out; |
| 101 | |
| 102 | if (!btrfs_devread(physical, clen, cbuf)) |
| 103 | goto err; |
| 104 | |
| 105 | res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen); |
| 106 | if (res == -1) |
| 107 | goto err; |
| 108 | |
| 109 | if (dlen > orig_size) |
| 110 | memcpy(out, dbuf + offset, size); |
| 111 | else |
| 112 | memmove(out, dbuf + offset, size); |
| 113 | |
| 114 | free(cbuf); |
| 115 | return res; |
| 116 | |
| 117 | err: |
| 118 | free(cbuf); |
| 119 | return -1ULL; |
| 120 | } |