- Read path: eliminate redundant allocation in bsPerformCommand - remove
the pre-allocation before bs.Read() and the append loop for zero-fill,
use direct copy and in-place zero-fill instead
- parseHeader: use command pool (getCommand) instead of direct allocation,
reducing GC pressure on the hot path
- Unmap: use a shared 1MB zero buffer instead of allocating per-descriptor,
dramatically reducing allocations for large unmap operations
- Network I/O: add 256KB bufio.Writer to iSCSI connections, batching
small PDU writes into fewer syscalls. Flush after txHandler completes
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The UNMAP command was a no-op in all backing stores, causing unmapped
blocks to retain stale data instead of returning zeros per SCSI spec.
- Implement Unmap in FileBackingStore to zero out unmapped blocks
- Implement Unmap in IOUringBackingStore to zero out unmapped blocks
- Enable Unmap in RemBackingStore (was commented out)
- Change UnmapBlockDescriptor.TL from uint32 to uint64 to prevent
integer overflow when converting block count to byte length with
large block shifts
Fixes#119
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Convert constant to var so that it can be configured from backend
- Add options to disable persistent reservation and ORWrite16 commands
Signed-off-by: Utkarsh Mani Tripathi <utkarsh.tripathi@mayadata.io>
- support Block Limits VPD page (0xB0)
- add UNMAP to REPORT SUPPORTED OPERATION CODES
- READ CAPACITY(16): set LBPME when Thin provisioning is enabled
- move Thinprovisioning and BlockShift to config
- add Unmap to BackingStore
