int nxffs_wrverify(FAR struct nxffs_volume_s *volume, size_t size)
{
uint16_t iooffset;
int nerased;
int ret;
int i;
/* Search to the very last block in the volume if we have to */
while (volume->ioblock < volume->nblocks)
{
/* Make sure that the block is in memory */
ret = nxffs_rdcache(volume, volume->ioblock);
if (ret < 0)
{
/* Ignore the error... just skip to the next block. This should
* never happen with normal FLASH, but could occur with NAND if
* the block has uncorrectable bit errors.
*/
fdbg("ERROR: Failed to read block %d: %d\n",
volume->ioblock, -ret);
}
/* Search to the very end of this block if we have to */
else
{
iooffset = volume->iooffset;
nerased = 0;
for (i = volume->iooffset; i < volume->geo.blocksize; i++)
{
/* Is this byte erased? */
if (volume->cache[i] == CONFIG_NXFFS_ERASEDSTATE)
{
/* Yes.. increment the count of contiguous, erased bytes */
nerased++;
/* Is the whole header memory erased? */
if (nerased >= size)
{
/* Yes.. this this is where we will put the object */
off_t offset =
volume->ioblock * volume->geo.blocksize + iooffset;
/* Update the free flash offset and return success */
volume->froffset = offset + size;
return OK;
}
}
/* This byte is not erased! (It should be unless the block is
* bad)
*/
else
{
nerased = 0;
iooffset = i + 1;
}
}
}
/* If we get here, then either (1) this block is not read-able, or
* (2) we have looked at every byte in the block and did not find
* any sequence of erased bytes long enough to hold the object.
* Skip to the next, valid block.
*/
volume->ioblock++;
ret = nxffs_validblock(volume, &volume->ioblock);
if (ret < 0)
{
fdbg("ERROR: No more valid blocks\n");
return ret;
}
volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
volume->froffset = volume->ioblock * volume->geo.blocksize + SIZEOF_NXFFS_BLOCK_HDR;
}
/* Return -ENOSPC if there is no erased memory left in the volume for
* the object.
*/
fdbg("ERROR: Not enough memory left to hold the file header\n");
return -ENOSPC;
}
int nxffs_limits(FAR struct nxffs_volume_s *volume)
{
FAR struct nxffs_entry_s entry;
off_t block;
off_t offset;
bool noinodes = false;
int nerased;
int ret;
/* Get the offset to the first valid block on the FLASH */
block = 0;
ret = nxffs_validblock(volume, &block);
if (ret < 0)
{
fdbg("Failed to find a valid block: %d\n", -ret);
return ret;
}
/* Then find the first valid inode in or beyond the first valid block */
offset = block * volume->geo.blocksize;
ret = nxffs_nextentry(volume, offset, &entry);
if (ret < 0)
{
/* The value -ENOENT is special. This simply means that the FLASH
* was searched to the end and no valid inode was found... the file
* system is empty (or, in more perverse cases, all inodes are
* deleted or corrupted).
*/
if (ret != -ENOENT)
{
fdbg("nxffs_nextentry failed: %d\n", -ret);
return ret;
}
/* Set a flag the just indicates that no inodes were found. Later,
* we will set the location of the first inode to be the same as
* the location of the free FLASH region.
*/
fvdbg("No inodes found\n");
noinodes = true;
}
else
{
/* Save the offset to the first inode */
volume->inoffset = entry.hoffset;
fvdbg("First inode at offset %d\n", volume->inoffset);
/* Discard this entry and set the next offset. */
offset = nxffs_inodeend(volume, &entry);
nxffs_freeentry(&entry);
}
/* Now, search for the last valid entry */
if (!noinodes)
{
while ((ret = nxffs_nextentry(volume, offset, &entry)) == OK)
{
/* Discard the entry and guess the next offset. */
offset = nxffs_inodeend(volume, &entry);
nxffs_freeentry(&entry);
}
fvdbg("Last inode before offset %d\n", offset);
}
/* No inodes were found after this offset. Now search for a block of
* erased flash.
*/
nxffs_ioseek(volume, offset);
nerased = 0;
for (;;)
{
int ch = nxffs_getc(volume, 1);
if (ch < 0)
{
/* Failed to read the next byte... this could mean that the FLASH
* is full?
*/
if (volume->ioblock + 1 >= volume->nblocks &&
volume->iooffset + 1 >= volume->geo.blocksize)
{
/* Yes.. the FLASH is full. Force the offsets to the end of FLASH */
volume->froffset = volume->nblocks * volume->geo.blocksize;
fvdbg("Assume no free FLASH, froffset: %d\n", volume->froffset);
if (noinodes)
{
volume->inoffset = volume->froffset;
fvdbg("No inodes, inoffset: %d\n", volume->inoffset);
}
return OK;
}
// No? Then it is some other failure that we do not know how to handle
fdbg("nxffs_getc failed: %d\n", -ch);
return ch;
}
/* Check for another erased byte */
else if (ch == CONFIG_NXFFS_ERASEDSTATE)
{
/* If we have encountered NXFFS_NERASED number of consecutive
* erased bytes, then presume we have reached the end of valid
* data.
*/
if (++nerased >= NXFFS_NERASED)
{
/* Okay.. we have a long stretch of erased FLASH in a valid
* FLASH block. Let's say that this is the beginning of
* the free FLASH region.
*/
volume->froffset = offset;
fvdbg("Free FLASH region begins at offset: %d\n", volume->froffset);
if (noinodes)
{
volume->inoffset = offset;
fvdbg("First inode at offset %d\n", volume->inoffset);
}
return OK;
}
}
else
{
offset += nerased + 1;
nerased = 0;
}
}
/* Won't get here */
return OK;
}
int nxffs_wrreserve(FAR struct nxffs_volume_s *volume, size_t size)
{
int ret;
/* Seek to the beginning of the free FLASH region */
nxffs_ioseek(volume, volume->froffset);
/* Check for a seek past the end of the volume */
if (volume->ioblock >= volume->nblocks)
{
/* Return -ENOSPC to indicate that the volume is full */
return -ENOSPC;
}
/* Skip over block headers */
if (volume->iooffset < SIZEOF_NXFFS_BLOCK_HDR)
{
volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
}
/* Make sure that there is space there to hold the entire object */
if (volume->iooffset + size > volume->geo.blocksize)
{
/* We will need to skip to the next block. But first, check if we are
* already at the final block.
*/
if (volume->ioblock + 1 >= volume->nblocks)
{
/* Return -ENOSPC to indicate that the volume is full */
fdbg("ERROR: No space in last block\n");
return -ENOSPC;
}
/* This is not the last block in the volume, so just seek to the
* beginning of the next, valid block.
*/
volume->ioblock++;
ret = nxffs_validblock(volume, &volume->ioblock);
if (ret < 0)
{
fdbg("ERROR: No more valid blocks\n");
return ret;
}
volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
}
/* Update the pointer to the first next free FLASH memory -- reserving this
* block of memory.
*/
volume->froffset = nxffs_iotell(volume) + size;
return OK;
}
