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; |
|
} |
|
/** |