int
nffs_crc_flash(uint16_t initial_crc, uint8_t area_idx, uint32_t area_offset,
uint32_t len, uint16_t *out_crc)
{
uint32_t chunk_len;
uint16_t crc;
int rc;
crc = initial_crc;
/* Copy data in chunks small enough to fit in the flash buffer. */
while (len > 0) {
if (len > sizeof nffs_flash_buf) {
chunk_len = sizeof nffs_flash_buf;
} else {
chunk_len = len;
}
rc = nffs_flash_read(area_idx, area_offset, nffs_flash_buf, chunk_len);
if (rc != 0) {
return rc;
}
crc = crc16_ccitt(crc, nffs_flash_buf, chunk_len);
area_offset += chunk_len;
len -= chunk_len;
}
*out_crc = crc;
return 0;
}
/**
* Turns a scratch area into a non-scratch area. If the specified area is not
* actually a scratch area, this function falls back to a slower full format
* operation.
*/
int
nffs_format_from_scratch_area(uint8_t area_idx, uint8_t area_id)
{
struct nffs_disk_area disk_area;
int rc;
assert(area_idx < nffs_num_areas);
rc = nffs_flash_read(area_idx, 0, &disk_area, sizeof disk_area);
if (rc != 0) {
return rc;
}
nffs_areas[area_idx].na_id = area_id;
if (!nffs_area_is_scratch(&disk_area)) {
rc = nffs_format_area(area_idx, 0);
if (rc != 0) {
return rc;
}
} else {
disk_area.nda_id = area_id;
rc = nffs_flash_write(area_idx, NFFS_AREA_OFFSET_ID,
&disk_area.nda_id, sizeof disk_area.nda_id);
if (rc != 0) {
return rc;
}
}
return 0;
}
/**
* Copies a chunk of data from one region of flash to another.
*
* @param area_idx_from The index of the area to copy from.
* @param area_offset_from The offset within the area to copy from.
* @param area_idx_to The index of the area to copy to.
* @param area_offset_to The offset within the area to copy to.
* @param len The number of bytes to copy.
*
* @return 0 on success; nonzero on failure.
*/
int
nffs_flash_copy(uint8_t area_idx_from, uint32_t area_offset_from,
uint8_t area_idx_to, uint32_t area_offset_to,
uint32_t len)
{
uint32_t chunk_len;
int rc;
/* Copy data in chunks small enough to fit in the flash buffer. */
while (len > 0) {
if (len > sizeof nffs_flash_buf) {
chunk_len = sizeof nffs_flash_buf;
} else {
chunk_len = len;
}
rc = nffs_flash_read(area_idx_from, area_offset_from, nffs_flash_buf,
chunk_len);
if (rc != 0) {
return rc;
}
rc = nffs_flash_write(area_idx_to, area_offset_to, nffs_flash_buf,
chunk_len);
if (rc != 0) {
return rc;
}
area_offset_from += chunk_len;
area_offset_to += chunk_len;
len -= chunk_len;
}
return 0;
}
/**
* Reads a single disk object from flash.
*
* @param area_idx The area to read the object from.
* @param area_offset The offset within the area to read from.
* @param out_disk_object On success, the restored object gets written
* here.
*
* @return 0 on success; nonzero on failure.
*/
static int
nffs_restore_disk_object(int area_idx, uint32_t area_offset,
struct nffs_disk_object *out_disk_object)
{
int rc;
rc = nffs_flash_read(area_idx, area_offset,
&out_disk_object->ndo_un_obj,
sizeof(out_disk_object->ndo_un_obj));
if (rc != 0) {
return rc;
}
STATS_INC(nffs_stats, nffs_readcnt_object);
if (nffs_hash_id_is_inode(out_disk_object->ndo_disk_inode.ndi_id)) {
out_disk_object->ndo_type = NFFS_OBJECT_TYPE_INODE;
} else if (nffs_hash_id_is_block(out_disk_object->ndo_disk_block.ndb_id)) {
out_disk_object->ndo_type = NFFS_OBJECT_TYPE_BLOCK;
} else if (out_disk_object->ndo_disk_block.ndb_id == NFFS_ID_NONE) {
return FS_EEMPTY;
} else {
return FS_ECORRUPT;
}
out_disk_object->ndo_area_idx = area_idx;
out_disk_object->ndo_offset = area_offset;
return 0;
}
/**
* Reads a data block header from flash.
*
* @param area_idx The index of the area to read from.
* @param area_offset The offset within the area to read from.
* @param out_disk_block On success, the block header is writteh here.
*
* @return 0 on success; nonzero on failure.
*/
int
nffs_block_read_disk(uint8_t area_idx, uint32_t area_offset,
struct nffs_disk_block *out_disk_block)
{
int rc;
rc = nffs_flash_read(area_idx, area_offset, out_disk_block,
sizeof *out_disk_block);
if (rc != 0) {
return rc;
}
if (out_disk_block->ndb_magic != NFFS_BLOCK_MAGIC) {
return FS_EUNEXP;
}
return 0;
}
/**
* Reads a data block header from flash.
*
* @param area_idx The index of the area to read from.
* @param area_offset The offset within the area to read from.
* @param out_disk_block On success, the block header is writteh here.
*
* @return 0 on success;
* FS_EOFFSET on an attempt to read an invalid
* address range;
* FS_EHW on flash error;
* FS_EUNEXP if the specified disk location does
* not contain a block.
*/
int
nffs_block_read_disk(uint8_t area_idx, uint32_t area_offset,
struct nffs_disk_block *out_disk_block)
{
int rc;
rc = nffs_flash_read(area_idx, area_offset, out_disk_block,
sizeof *out_disk_block);
if (rc != 0) {
return rc;
}
if (!nffs_hash_id_is_block(out_disk_block->ndb_id)) {
return FS_EUNEXP;
}
return 0;
}
/**
* Reads a single disk object from flash.
*
* @param area_idx The area to read the object from.
* @param area_offset The offset within the area to read from.
* @param out_disk_object On success, the restored object gets written
* here.
*
* @return 0 on success; nonzero on failure.
*/
static int
nffs_restore_disk_object(int area_idx, uint32_t area_offset,
struct nffs_disk_object *out_disk_object)
{
uint32_t magic;
int rc;
rc = nffs_flash_read(area_idx, area_offset, &magic, sizeof magic);
if (rc != 0) {
return rc;
}
switch (magic) {
case NFFS_INODE_MAGIC:
out_disk_object->ndo_type = NFFS_OBJECT_TYPE_INODE;
rc = nffs_inode_read_disk(area_idx, area_offset,
&out_disk_object->ndo_disk_inode);
break;
case NFFS_BLOCK_MAGIC:
out_disk_object->ndo_type = NFFS_OBJECT_TYPE_BLOCK;
rc = nffs_block_read_disk(area_idx, area_offset,
&out_disk_object->ndo_disk_block);
break;
case 0xffffffff:
rc = FS_EEMPTY;
break;
default:
rc = FS_ECORRUPT;
break;
}
if (rc != 0) {
return rc;
}
out_disk_object->ndo_area_idx = area_idx;
out_disk_object->ndo_offset = area_offset;
return 0;
}
int
nffs_block_read_data(const struct nffs_block *block, uint16_t offset,
uint16_t length, void *dst)
{
uint32_t area_offset;
uint8_t area_idx;
int rc;
nffs_flash_loc_expand(block->nb_hash_entry->nhe_flash_loc,
&area_idx, &area_offset);
area_offset += sizeof (struct nffs_disk_block);
area_offset += offset;
rc = nffs_flash_read(area_idx, area_offset, dst, length);
if (rc != 0) {
return rc;
}
return 0;
}
/**
* Moves a chain of blocks from one area to another. This function attempts to
* collate the blocks into a single new block in the destination area.
*
* @param last_entry The last block entry in the chain.
* @param data_len The total length of data to collate.
* @param to_area_idx The index of the area to copy to.
* @param inout_next This parameter is only necessary if you are
* calling this function during an iteration
* of the entire hash table; pass null
* otherwise.
* On input, this points to the next hash entry
* you plan on processing.
* On output, this points to the next hash entry
* that should be processed.
*
* @return 0 on success;
* FS_ENOMEM if there is insufficient heap;
* other nonzero on failure.
*/
static int
nffs_gc_block_chain_collate(struct nffs_hash_entry *last_entry,
uint32_t data_len, uint8_t to_area_idx,
struct nffs_hash_entry **inout_next)
{
struct nffs_disk_block disk_block;
struct nffs_hash_entry *entry;
struct nffs_area *to_area;
struct nffs_block last_block;
struct nffs_block block;
uint32_t to_area_offset;
uint32_t from_area_offset;
uint32_t data_offset;
uint8_t *data;
uint8_t from_area_idx;
int rc;
memset(&last_block, 0, sizeof last_block);
data = malloc(data_len);
if (data == NULL) {
rc = FS_ENOMEM;
goto done;
}
memset(&last_block, 0, sizeof(last_block));
to_area = nffs_areas + to_area_idx;
entry = last_entry;
data_offset = data_len;
while (data_offset > 0) {
rc = nffs_block_from_hash_entry(&block, entry);
if (rc != 0) {
goto done;
}
data_offset -= block.nb_data_len;
nffs_flash_loc_expand(block.nb_hash_entry->nhe_flash_loc,
&from_area_idx, &from_area_offset);
from_area_offset += sizeof disk_block;
STATS_INC(nffs_stats, nffs_readcnt_gccollate);
rc = nffs_flash_read(from_area_idx, from_area_offset,
data + data_offset, block.nb_data_len);
if (rc != 0) {
goto done;
}
if (entry != last_entry) {
if (inout_next != NULL && *inout_next == entry) {
*inout_next = SLIST_NEXT(entry, nhe_next);
}
nffs_block_delete_from_ram(entry);
} else {
last_block = block;
}
entry = block.nb_prev;
}
/* we had better have found the last block */
assert(last_block.nb_hash_entry);
/* The resulting block should inherit its ID from its last constituent
* block (this is the ID referenced by the parent inode and subsequent data
* block). The previous ID gets inherited from the first constituent
* block.
*/
memset(&disk_block, 0, sizeof disk_block);
disk_block.ndb_id = last_block.nb_hash_entry->nhe_id;
disk_block.ndb_seq = last_block.nb_seq + 1;
disk_block.ndb_inode_id = last_block.nb_inode_entry->nie_hash_entry.nhe_id;
if (entry == NULL) {
disk_block.ndb_prev_id = NFFS_ID_NONE;
} else {
disk_block.ndb_prev_id = entry->nhe_id;
}
disk_block.ndb_data_len = data_len;
nffs_crc_disk_block_fill(&disk_block, data);
to_area_offset = to_area->na_cur;
rc = nffs_flash_write(to_area_idx, to_area_offset,
&disk_block, sizeof disk_block);
if (rc != 0) {
goto done;
}
rc = nffs_flash_write(to_area_idx, to_area_offset + sizeof disk_block,
data, data_len);
if (rc != 0) {
goto done;
}
last_entry->nhe_flash_loc = nffs_flash_loc(to_area_idx, to_area_offset);
rc = 0;
ASSERT_IF_TEST(nffs_crc_disk_block_validate(&disk_block, to_area_idx,
to_area_offset) == 0);
done:
free(data);
return rc;
}
/**
* Moves a chain of blocks from one area to another. This function attempts to
* collate the blocks into a single new block in the destination area.
*
* @param last_entry The last block entry in the chain.
* @param data_len The total length of data to collate.
* @param to_area_idx The index of the area to copy to.
* @param inout_next This parameter is only necessary if you are
* calling this function during an iteration
* of the entire hash table; pass null
* otherwise.
* On input, this points to the next hash entry
* you plan on processing.
* On output, this points to the next hash entry
* that should be processed.
*
* @return 0 on success;
* FS_ENOMEM if there is insufficient heap;
* other nonzero on failure.
*/
static int
nffs_gc_block_chain_collate(struct nffs_hash_entry *last_entry,
uint32_t data_len, uint8_t to_area_idx,
struct nffs_hash_entry **inout_next)
{
struct nffs_disk_block disk_block;
struct nffs_hash_entry *entry;
struct nffs_area *to_area;
struct nffs_block block;
uint32_t to_area_offset;
uint32_t from_area_offset;
uint32_t data_offset;
uint8_t *data;
uint8_t from_area_idx;
int rc;
data = malloc(data_len);
if (data == NULL) {
rc = FS_ENOMEM;
goto done;
}
to_area = nffs_areas + to_area_idx;
entry = last_entry;
data_offset = data_len;
while (data_offset > 0) {
rc = nffs_block_from_hash_entry(&block, entry);
if (rc != 0) {
goto done;
}
data_offset -= block.nb_data_len;
nffs_flash_loc_expand(block.nb_hash_entry->nhe_flash_loc,
&from_area_idx, &from_area_offset);
from_area_offset += sizeof disk_block;
rc = nffs_flash_read(from_area_idx, from_area_offset,
data + data_offset, block.nb_data_len);
if (rc != 0) {
goto done;
}
if (entry != last_entry) {
if (inout_next != NULL && *inout_next == entry) {
*inout_next = SLIST_NEXT(entry, nhe_next);
}
nffs_block_delete_from_ram(entry);
}
entry = block.nb_prev;
}
memset(&disk_block, 0, sizeof disk_block);
disk_block.ndb_magic = NFFS_BLOCK_MAGIC;
disk_block.ndb_id = block.nb_hash_entry->nhe_id;
disk_block.ndb_seq = block.nb_seq + 1;
disk_block.ndb_inode_id = block.nb_inode_entry->nie_hash_entry.nhe_id;
if (entry == NULL) {
disk_block.ndb_prev_id = NFFS_ID_NONE;
} else {
disk_block.ndb_prev_id = entry->nhe_id;
}
disk_block.ndb_data_len = data_len;
nffs_crc_disk_block_fill(&disk_block, data);
to_area_offset = to_area->na_cur;
rc = nffs_flash_write(to_area_idx, to_area_offset,
&disk_block, sizeof disk_block);
if (rc != 0) {
goto done;
}
rc = nffs_flash_write(to_area_idx, to_area_offset + sizeof disk_block,
data, data_len);
if (rc != 0) {
goto done;
}
last_entry->nhe_flash_loc = nffs_flash_loc(to_area_idx, to_area_offset);
rc = 0;
ASSERT_IF_TEST(nffs_crc_disk_block_validate(&disk_block, to_area_idx,
to_area_offset) == 0);
done:
free(data);
return rc;
}
