| 102,6 → 102,42 |
|---|
| block_put(b); |
| } |
| |
| static fat_node_t *fat_node_get_new(void) |
| { |
| fat_node_t *nodep; |
| |
| futex_down(&ffn_futex); |
| if (!list_empty(&ffn_head)) { |
| /* Try to use a cached free node structure. */ |
| fat_idx_t *idxp_tmp; |
| nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
| if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
| goto skip_cache; |
| idxp_tmp = nodep->idx; |
| if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
| futex_up(&nodep->lock); |
| goto skip_cache; |
| } |
| list_remove(&nodep->ffn_link); |
| futex_up(&ffn_futex); |
| if (nodep->dirty) |
| fat_node_sync(nodep); |
| idxp_tmp->nodep = NULL; |
| futex_up(&nodep->lock); |
| futex_up(&idxp_tmp->lock); |
| } else { |
| skip_cache: |
| /* Try to allocate a new node structure. */ |
| futex_up(&ffn_futex); |
| nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
| if (!nodep) |
| return NULL; |
| } |
| fat_node_initialize(nodep); |
| |
| return nodep; |
| } |
| |
| /** Internal version of fat_node_get(). |
| * |
| * @param idxp Locked index structure. |
| 134,34 → 170,9 |
|---|
| |
| assert(idxp->pfc); |
| |
| futex_down(&ffn_futex); |
| if (!list_empty(&ffn_head)) { |
| /* Try to use a cached free node structure. */ |
| fat_idx_t *idxp_tmp; |
| nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link); |
| if (futex_trydown(&nodep->lock) == ESYNCH_WOULD_BLOCK) |
| goto skip_cache; |
| idxp_tmp = nodep->idx; |
| if (futex_trydown(&idxp_tmp->lock) == ESYNCH_WOULD_BLOCK) { |
| futex_up(&nodep->lock); |
| goto skip_cache; |
| } |
| list_remove(&nodep->ffn_link); |
| futex_up(&ffn_futex); |
| if (nodep->dirty) |
| fat_node_sync(nodep); |
| idxp_tmp->nodep = NULL; |
| futex_up(&nodep->lock); |
| futex_up(&idxp_tmp->lock); |
| } else { |
| skip_cache: |
| /* Try to allocate a new node structure. */ |
| futex_up(&ffn_futex); |
| nodep = (fat_node_t *)malloc(sizeof(fat_node_t)); |
| if (!nodep) |
| return NULL; |
| } |
| fat_node_initialize(nodep); |
| nodep = fat_node_get_new(); |
| if (!nodep) |
| return NULL; |
| |
| bs = block_bb_get(idxp->dev_handle); |
| bps = uint16_t_le2host(bs->bps); |
| 233,7 → 244,7 |
|---|
| futex_up(&nodep->lock); |
| } |
| |
| static void *fat_create(int flags) |
| static void *fat_create(dev_handle_t dev_handle, int flags) |
| { |
| return NULL; /* not supported at the moment */ |
| } |
| 634,6 → 645,7 |
|---|
| block_t *b; |
| uint16_t bps; |
| unsigned spc; |
| unsigned bpc; /* bytes per cluster */ |
| off_t boundary; |
| |
| if (!nodep) { |
| 650,6 → 662,11 |
|---|
| 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 → 675,8 |
|---|
| * 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 |
| 681,8 → 694,8 |
|---|
| nodep->size = pos + bytes; |
| nodep->dirty = true; /* need to sync node */ |
| } |
| ipc_answer_2(rid, EOK, bytes, nodep->size); |
| fat_node_put(nodep); |
| ipc_answer_1(rid, EOK, bytes); |
| return; |
| } else { |
| /* |
| 693,11 → 706,9 |
|---|
| 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); |
| 719,8 → 730,8 |
|---|
| fat_append_clusters(bs, nodep, mcl); |
| nodep->size = pos + bytes; |
| nodep->dirty = true; /* need to sync node */ |
| ipc_answer_2(rid, EOK, bytes, nodep->size); |
| fat_node_put(nodep); |
| ipc_answer_1(rid, EOK, bytes); |
| return; |
| } |
| } |
| 731,6 → 742,10 |
|---|
| 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 → 753,45 |
|---|
| 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; |
| |
| } |
| |
| /** |