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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 | // SPDX-License-Identifier: GPL-2.0 /* * 2017 by Marek Behún <kabel@kernel.org> * * Derived from code in ext4/dev.c, which was based on reiserfs/dev.c */ #define LOG_CATEGORY LOGC_CORE #include <blk.h> #include <compiler.h> #include <log.h> #include <part.h> #include <memalign.h> int fs_devread(struct blk_desc *blk, struct disk_partition *partition, lbaint_t sector, int byte_offset, int byte_len, char *buf) { unsigned block_len; int log2blksz; ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (blk ? blk->blksz : 0)); if (blk == NULL) { log_err("** Invalid Block Device Descriptor (NULL)\n"); return 0; } log2blksz = blk->log2blksz; /* Check partition boundaries */ if ((sector + ((byte_offset + byte_len - 1) >> log2blksz)) >= partition->size) { log_err("** Read outside partition " LBAFU "\n", sector); return 0; } /* Get the read to the beginning of a partition */ sector += byte_offset >> log2blksz; byte_offset &= blk->blksz - 1; log_debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len); if (byte_offset != 0) { int readlen; /* read first part which isn't aligned with start of sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s read error **\n", __func__); return 0; } readlen = min((int)blk->blksz - byte_offset, byte_len); memcpy(buf, sec_buf + byte_offset, readlen); buf += readlen; byte_len -= readlen; sector++; } if (byte_len == 0) return 1; /* read sector aligned part */ block_len = byte_len & ~(blk->blksz - 1); if (block_len == 0) { ALLOC_CACHE_ALIGN_BUFFER(u8, p, blk->blksz); block_len = blk->blksz; blk_dread(blk, partition->start + sector, 1, (void *)p); memcpy(buf, p, byte_len); return 1; } if (blk_dread(blk, partition->start + sector, block_len >> log2blksz, (void *)buf) != block_len >> log2blksz) { log_err(" ** %s read error - block\n", __func__); return 0; } block_len = byte_len & ~(blk->blksz - 1); buf += block_len; byte_len -= block_len; sector += block_len / blk->blksz; if (byte_len != 0) { /* read rest of data which are not in whole sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err("* %s read error - last part\n", __func__); return 0; } memcpy(buf, sec_buf, byte_len); } return 1; } int fs_devwrite(struct blk_desc *blk, struct disk_partition *partition, lbaint_t sector, int byte_offset, int byte_len, const char *buf) { unsigned block_len; int log2blksz; ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (blk ? blk->blksz : 0)); if (blk == NULL) { log_err("** Invalid Block Device Descriptor (NULL)\n"); return 0; } log2blksz = blk->log2blksz; /* Check partition boundaries */ if ((sector + ((byte_offset + byte_len - 1) >> log2blksz)) >= partition->size) { log_debug("read outside partition " LBAFU "\n", sector); return 0; } /* Get the read to the beginning of a partition */ sector += byte_offset >> log2blksz; byte_offset &= blk->blksz - 1; log_debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len); if (byte_offset != 0) { int readlen; /* read first part which isn't aligned with start of sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s read error **\n", __func__); return 0; } readlen = min((int)blk->blksz - byte_offset, byte_len); memcpy(sec_buf + byte_offset, buf, readlen); if (blk_dwrite(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s write error **\n", __func__); return 0; } buf += readlen; byte_len -= readlen; sector++; } if (byte_len == 0) return 1; /* write sector aligned part */ block_len = byte_len & ~(blk->blksz - 1); if (block_len == 0) { if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s read error **\n", __func__); return 0; } memcpy(sec_buf, buf, byte_len); if (blk_dwrite(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s write error **\n", __func__); return 0; } return 1; } if (blk_dwrite(blk, partition->start + sector, block_len >> log2blksz, (void *)buf) != block_len >> log2blksz) { log_err(" ** %s write error - block\n", __func__); return 0; } block_len = byte_len & ~(blk->blksz - 1); buf += block_len; byte_len -= block_len; sector += block_len / blk->blksz; if (byte_len != 0) { /* read rest of data which are not in whole sector */ if (blk_dread(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err("* %s read error - last part **\n", __func__); return 0; } memcpy(sec_buf, buf, byte_len); if (blk_dwrite(blk, partition->start + sector, 1, (void *)sec_buf) != 1) { log_err(" ** %s write error - last part **\n", __func__); return 0; } } return 1; } |