status_t
Inode::_ShrinkDataStream(Transaction& transaction, off_t size)
{
TRACE("Inode::_ShrinkDataStream()\n");
if (size < 0)
return B_BAD_VALUE;
uint32 blockSize = fVolume->BlockSize();
off_t oldSize = Size();
off_t lastByte = oldSize == 0 ? 0 : oldSize - 1;
off_t minSize = (lastByte / blockSize + 1) * blockSize;
// Minimum size that doesn't require freeing blocks
if (size > minSize) {
// No need to allocate more blocks
TRACE("Inode::_ShrinkDataStream(): No need to allocate more blocks\n");
TRACE("Inode::_ShrinkDataStream(): Setting size to %lld\n", size);
fNode.SetSize(size);
return B_OK;
}
off_t end = size == 0 ? 0 : (size - 1) / fVolume->BlockSize() + 1;
if (Flags() & EXT2_INODE_EXTENTS) {
ExtentStream stream(fVolume, &fNode.extent_stream, Size());
stream.Shrink(transaction, end);
ASSERT(stream.Check());
} else {
DataStream stream(fVolume, &fNode.stream, oldSize);
stream.Shrink(transaction, end);
}
fNode.SetSize(size);
return _SetNumBlocks(_NumBlocks() - end * (fVolume->BlockSize() / 512));
}
status_t
Inode::_EnlargeDataStream(Transaction& transaction, off_t size)
{
if (size < 0)
return B_BAD_VALUE;
TRACE("Inode::_EnlargeDataStream()\n");
uint32 blockSize = fVolume->BlockSize();
off_t oldSize = Size();
off_t maxSize = oldSize;
if (maxSize % blockSize != 0)
maxSize += blockSize - maxSize % blockSize;
if (size <= maxSize) {
// No need to allocate more blocks
TRACE("Inode::_EnlargeDataStream(): No need to allocate more blocks\n");
TRACE("Inode::_EnlargeDataStream(): Setting size to %" B_PRIdOFF "\n",
size);
fNode.SetSize(size);
return B_OK;
}
off_t end = size == 0 ? 0 : (size - 1) / fVolume->BlockSize() + 1;
if (Flags() & EXT2_INODE_EXTENTS) {
ExtentStream stream(fVolume, &fNode.extent_stream, Size());
stream.Enlarge(transaction, end);
ASSERT(stream.Check());
} else {
DataStream stream(fVolume, &fNode.stream, oldSize);
stream.Enlarge(transaction, end);
}
TRACE("Inode::_EnlargeDataStream(): Setting size to %" B_PRIdOFF "\n",
size);
fNode.SetSize(size);
TRACE("Inode::_EnlargeDataStream(): Setting allocated block count to %"
B_PRIdOFF "\n", end);
return _SetNumBlocks(_NumBlocks() + end * (fVolume->BlockSize() / 512));
}
