| 634,6 → 634,7 |
|---|
| block_t *b; |
| uint16_t bps; |
| unsigned spc; |
| unsigned bpc; /* bytes per cluster */ |
| off_t boundary; |
| |
| if (!nodep) { |
| 650,6 → 651,11 |
|---|
| return; |
| } |
| |
| bs = block_bb_get(dev_handle); |
| bps = uint16_t_le2host(bs->bps); |
| spc = bs->spc; |
| bpc = bps * spc; |
| |
| /* |
| * In all scenarios, we will attempt to write out only one block worth |
| * of data at maximum. There might be some more efficient approaches, |
| 658,12 → 664,8 |
|---|
| * value signalizing a smaller number of bytes written. |
| */ |
| bytes = min(len, bps - pos % bps); |
| |
| bs = block_bb_get(dev_handle); |
| bps = uint16_t_le2host(bs->bps); |
| spc = bs->spc; |
| |
| boundary = ROUND_UP(nodep->size, bps * spc); |
| boundary = ROUND_UP(nodep->size, bpc); |
| if (pos < boundary) { |
| /* |
| * This is the easier case - we are either overwriting already |
| 693,11 → 695,9 |
|---|
| unsigned nclsts; |
| fat_cluster_t mcl, lcl; |
| |
| nclsts = (ROUND_UP(pos + bytes, bps * spc) - boundary) / |
| bps * spc; |
| nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc; |
| /* create an independent chain of nclsts clusters in all FATs */ |
| status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, |
| &lcl); |
| status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl); |
| if (status != EOK) { |
| /* could not allocate a chain of nclsts clusters */ |
| fat_node_put(nodep); |
| 731,6 → 731,10 |
|---|
| fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| size_t size = (off_t)IPC_GET_ARG3(*request); |
| fat_node_t *nodep = (fat_node_t *)fat_node_get(dev_handle, index); |
| fat_bs_t *bs; |
| uint16_t bps; |
| uint8_t spc; |
| unsigned bpc; /* bytes per cluster */ |
| int rc; |
| |
| if (!nodep) { |
| 738,24 → 742,45 |
|---|
| return; |
| } |
| |
| bs = block_bb_get(dev_handle); |
| bps = uint16_t_le2host(bs->bps); |
| spc = bs->spc; |
| bpc = bps * spc; |
| |
| if (nodep->size == size) { |
| rc = EOK; |
| } else if (nodep->size < size) { |
| /* |
| * TODO: the standard says we have the freedom to grow the file. |
| * The standard says we have the freedom to grow the node. |
| * For now, we simply return an error. |
| */ |
| rc = EINVAL; |
| } else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) { |
| /* |
| * The node will be shrunk, but no clusters will be deallocated. |
| */ |
| nodep->size = size; |
| nodep->dirty = true; /* need to sync node */ |
| rc = EOK; |
| } else { |
| /* |
| * The file is to be shrunk. |
| * The node will be shrunk, clusters will be deallocated. |
| */ |
| rc = ENOTSUP; /* XXX */ |
| if (size == 0) { |
| fat_chop_clusters(bs, nodep, FAT_CLST_RES0); |
| } else { |
| fat_cluster_t lastc; |
| (void) fat_cluster_walk(bs, dev_handle, nodep->firstc, |
| &lastc, (size - 1) / bpc); |
| fat_chop_clusters(bs, nodep, lastc); |
| } |
| nodep->size = size; |
| nodep->dirty = true; /* need to sync node */ |
| rc = EOK; |
| } |
| fat_node_put(nodep); |
| ipc_answer_0(rid, rc); |
| return; |
| |
| } |
| |
| /** |