| 59,10 → 59,7 |
|---|
| * @param bs Buffer holding the boot sector for the file. |
| * @param dev_handle Device handle of the device with the file. |
| * @param firstc First cluster to start the walk with. |
| * @param penult If non-NULL, output argument hodling the |
| * the penultimate cluster visited. |
| * @param ult If non-NULL, output argument holding the |
| * ultimate cluster visited. |
| * @param lastc If non-NULL, output argument hodling the last cluster number visited. |
| * @param max_clusters Maximum number of clusters to visit. |
| * |
| * @return Number of clusters seen during the walk. |
| 69,7 → 66,7 |
|---|
| */ |
| uint16_t |
| fat_cluster_walk(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
| fat_cluster_t *penult, fat_cluster_t *ult, uint16_t max_clusters) |
| fat_cluster_t *lastc, uint16_t max_clusters) |
| { |
| block_t *b; |
| unsigned bps; |
| 82,22 → 79,18 |
|---|
| |
| if (firstc == FAT_CLST_RES0) { |
| /* No space allocated to the file. */ |
| if (ult) |
| *ult = firstc; |
| if (lastc) |
| *lastc = firstc; |
| return 0; |
| } |
| |
| /* At this point, the meaning of penult is not well-defined. */ |
| if (penult) |
| *penult = FAT_CLST_RES0; |
| |
| while (clst < FAT_CLST_LAST1 && clusters < max_clusters) { |
| unsigned fsec; /* sector offset relative to FAT1 */ |
| bn_t fsec; /* sector offset relative to FAT1 */ |
| unsigned fidx; /* FAT1 entry index */ |
| |
| assert(clst >= FAT_CLST_FIRST); |
| if (penult) |
| *penult = clst; /* remember the penultimate cluster */ |
| if (lastc) |
| *lastc = clst; /* remember the last cluster number */ |
| fsec = (clst * sizeof(fat_cluster_t)) / bps; |
| fidx = clst % (bps / sizeof(fat_cluster_t)); |
| /* read FAT1 */ |
| 108,8 → 101,8 |
|---|
| clusters++; |
| } |
| |
| if (ult) |
| *ult = clst; |
| if (lastc && clst < FAT_CLST_LAST1) |
| *lastc = clst; |
| |
| return clusters; |
| } |
| 120,13 → 113,13 |
|---|
| * @param dev_handle Device handle of the file system. |
| * @param firstc First cluster used by the file. Can be zero if the file |
| * is empty. |
| * @param offset Offset in blocks. |
| * @param bn Block number. |
| * |
| * @return Block structure holding the requested block. |
| */ |
| block_t * |
| _fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc, |
| off_t offset) |
| bn_t bn) |
| { |
| block_t *b; |
| unsigned bps; |
| 149,18 → 142,18 |
|---|
| |
| if (firstc == FAT_CLST_ROOT) { |
| /* root directory special case */ |
| assert(offset < rds); |
| b = block_get(dev_handle, rscnt + bs->fatcnt * sf + offset); |
| assert(bn < rds); |
| b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn); |
| return b; |
| } |
| |
| max_clusters = offset / bs->spc; |
| clusters = fat_cluster_walk(bs, dev_handle, firstc, NULL, &lastc, |
| max_clusters = bn / bs->spc; |
| clusters = fat_cluster_walk(bs, dev_handle, firstc, &lastc, |
| max_clusters); |
| assert(clusters == max_clusters); |
| |
| b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc + |
| offset % bs->spc); |
| bn % bs->spc); |
| |
| return b; |
| } |
| 361,7 → 354,7 |
|---|
| uint8_t fatno; |
| |
| if (fat_cluster_walk(bs, nodep->idx->dev_handle, nodep->firstc, &lcl, |
| NULL, (uint16_t) -1) == 0) { |
| (uint16_t) -1) == 0) { |
| /* No clusters allocated to the node yet. */ |
| nodep->firstc = host2uint16_t_le(mcl); |
| nodep->dirty = true; /* need to sync node */ |