| 129,7 → 129,7 |
|---|
| unsigned sf; |
| unsigned ssa; /* size of the system area */ |
| unsigned clusters, max_clusters; |
| fat_cluster_t lastc, clst = firstc; |
| fat_cluster_t lastc; |
| |
| bps = uint16_t_le2host(bs->bps); |
| rscnt = uint16_t_le2host(bs->rscnt); |
| 158,7 → 158,6 |
|---|
| return b; |
| } |
| |
| |
| /** Fill the gap between EOF and a new file position. |
| * |
| * @param bs Buffer holding the boot sector for nodep. |
| 203,16 → 202,43 |
|---|
| } |
| } |
| |
| /** Mark cluster in one instance of FAT. |
| /** Get cluster from the first FAT. |
| * |
| * @param bs Buffer holding the boot sector for the file system. |
| * @param dev_handle Device handle for the file system. |
| * @param clst Cluster which to get. |
| * |
| * @return Value found in the cluster. |
| */ |
| fat_cluster_t |
| fat_get_cluster(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t clst) |
| { |
| block_t *b; |
| uint16_t bps; |
| uint16_t rscnt; |
| fat_cluster_t *cp, value; |
| |
| bps = uint16_t_le2host(bs->bps); |
| rscnt = uint16_t_le2host(bs->rscnt); |
| |
| b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps); |
| cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t)); |
| value = uint16_t_le2host(*cp); |
| block_put(b); |
| |
| return value; |
| } |
| |
| /** Set cluster in one instance of FAT. |
| * |
| * @param bs Buffer holding the boot sector for the file system. |
| * @param dev_handle Device handle for the file system. |
| * @param fatno Number of the FAT instance where to make the change. |
| * @param clst Cluster which is to be marked. |
| * @param value Value mark the cluster with. |
| * @param clst Cluster which is to be set. |
| * @param value Value to set the cluster with. |
| */ |
| void |
| fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno, |
| fat_set_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno, |
| fat_cluster_t clst, fat_cluster_t value) |
| { |
| block_t *b; |
| 249,7 → 275,7 |
|---|
| |
| for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) { |
| for (c = 0; c < nclsts; c++) { |
| fat_mark_cluster(bs, dev_handle, fatno, lifo[c], |
| fat_set_cluster(bs, dev_handle, fatno, lifo[c], |
| c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]); |
| } |
| } |
| 333,7 → 359,7 |
|---|
| * we have allocated so far. |
| */ |
| while (found--) { |
| fat_mark_cluster(bs, dev_handle, FAT1, lifo[found], |
| fat_set_cluster(bs, dev_handle, FAT1, lifo[found], |
| FAT_CLST_RES0); |
| } |
| |
| 341,9 → 367,32 |
|---|
| return ENOSPC; |
| } |
| |
| /** Free clusters forming a cluster chain in all copies of FAT. |
| * |
| * @param bs Buffer hodling the boot sector of the file system. |
| * @param dev_handle Device handle of the file system. |
| * @param firstc First cluster in the chain which is to be freed. |
| */ |
| void |
| fat_free_clusters(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc) |
| { |
| unsigned fatno; |
| fat_cluster_t nextc; |
| |
| /* Mark all clusters in the chain as free in all copies of FAT. */ |
| while (firstc < FAT_CLST_LAST1) { |
| nextc = fat_get_cluster(bs, dev_handle, firstc); |
| assert(nextc >= FAT_CLST_FIRST && nextc < FAT_CLST_BAD); |
| for (fatno = FAT1; fatno < bs->fatcnt; fatno++) |
| fat_set_cluster(bs, dev_handle, fatno, firstc, |
| FAT_CLST_RES0); |
| firstc = nextc; |
| } |
| } |
| |
| /** Append a cluster chain to the last file cluster in all FATs. |
| * |
| * @param bs Buffer holding boot sector of the file system. |
| * @param bs Buffer holding the boot sector of the file system. |
| * @param nodep Node representing the file. |
| * @param mcl First cluster of the cluster chain to append. |
| */ |
| 353,7 → 402,7 |
|---|
| fat_cluster_t lcl; |
| uint8_t fatno; |
| |
| if (fat_cluster_walk(bs, nodep->idx->dev_handle, nodep->firstc, &lcl, |
| if (fat_cluster_walk(bs, dev_handle, nodep->firstc, &lcl, |
| (uint16_t) -1) == 0) { |
| /* No clusters allocated to the node yet. */ |
| nodep->firstc = host2uint16_t_le(mcl); |
| 362,9 → 411,40 |
|---|
| } |
| |
| for (fatno = FAT1; fatno < bs->fatcnt; fatno++) |
| fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl); |
| fat_set_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl); |
| } |
| |
| /** Chop off node clusters in all copies of FAT. |
| * |
| * @param bs Buffer holding the boot sector of the file system. |
| * @param nodep FAT node where the chopping will take place. |
| * @param lastc Last cluster which will remain in the node. If this |
| * argument is FAT_CLST_RES0, then all clusters will |
| * be choped off. |
| */ |
| void fat_chop_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t lastc) |
| { |
| dev_handle_t dev_handle = nodep->idx->dev_handle; |
| if (lastc == FAT_CLST_RES0) { |
| /* The node will have zero size and no clusters allocated. */ |
| fat_free_clusters(bs, dev_handle, nodep->firstc); |
| nodep->firstc = FAT_CLST_RES0; |
| nodep->dirty = true; /* need to sync node */ |
| } else { |
| fat_cluster_t nextc; |
| unsigned fatno; |
| |
| nextc = fat_get_cluster(bs, dev_handle, lastc); |
| |
| /* Terminate the cluster chain in all copies of FAT. */ |
| for (fatno = FAT1; fatno < bs->fatcnt; fatno++) |
| fat_set_cluster(bs, dev_handle, fatno, lastc, FAT_CLST_LAST1); |
| |
| /* Free all following clusters. */ |
| fat_free_clusters(bs, dev_handle, nextc); |
| } |
| } |
| |
| /** |
| * @} |
| */ |