Struct DeviceBlockStore 

pub struct DeviceBlockStore { /* private fields */ }

Block-device-backed block store for raw devices such as EBS volumes.

Unlike DiskBlockStore which operates on regular files, this backend targets raw block devices (e.g. /dev/xvdf, /dev/nvme1n1p1). The device must already exist; Linux does not allow creating device nodes from userspace in the normal flow.

Device size is discovered via lseek(SEEK_END) because stat() reports st_size = 0 for block devices. I/O uses pread/pwrite (via FileExt) exactly like DiskBlockStore.

Implementations

impl DeviceBlockStore

pub fn open(path: &str, block_size: usize, total_blocks: u64) -> FsResult<Self>

Open an existing block device.

total_blocks – pass 0 to infer from the device size.

pub fn initialize( path: &str, block_size: usize, total_blocks: u64, ) -> FsResult<Self>

Initialize a block device by filling every block with random data so that free space is indistinguishable from ciphertext.

Warning: this writes to every block and can take a long time on large volumes. Call this once when first provisioning the device.

total_blocks – pass 0 to use the entire device.

Trait Implementations

impl BlockStore for DeviceBlockStore

fn block_size(&self) -> usize

Block size in bytes.

fn total_blocks(&self) -> u64

Total number of blocks in the store.

fn read_block(&self, block_id: u64) -> FsResult<Vec<u8>>

Read a full block. Returns exactly block_size() bytes.

fn write_block(&self, block_id: u64, data: &[u8]) -> FsResult<()>

Write a full block. data must be exactly block_size() bytes.

fn sync(&self) -> FsResult<()>

Sync / flush all writes. No-op for in-memory stores.

fn read_blocks(&self, block_ids: &[u64]) -> FsResult<Vec<Vec<u8>>>

Read multiple blocks in one call.

fn write_blocks(&self, blocks: &[(u64, &[u8])]) -> FsResult<()>

Write multiple blocks in one call.