Hi Enzo, ... > On Thu 14-03-24 15:14:49, Enzo Matsumiya wrote: > > Hello, > > > > Having implemented data compression for SMB2 messages in cifs.ko, I'd > > like to attend LSF/MM to discuss: > > > > - implementation decisions, both in the protocol level and in the > > compression algorithms; e.g. performance improvements, what could, > > if possible/wanted, turn into a lib/ module, etc > > > > - compression algorithms in general; talk about algorithms to determine > > if/how compressible a blob of data is > > * several such algorithms already exist and are used by on-disk > > compression tools, but for over-the-wire compression maybe the > > fastest one with good (not great nor best) predictability > > could work? Ideally there could be some overlap between on-disk and over-the-wire compression algorithm support. That could allow optimally aligned / sized IOs to avoid unnecessary compression / decompression cycles on an SMB server / client if the underlying filesystem supports encoded I/O via e.g. BTRFS_IOC_ENCODED_READ/WRITE. IIUC, we currently have: SMB: LZ77, LZ77+Huffman (DEFLATE?), LZNT1, LZ4 Btrfs: zlib/DEFLATE, LZO, Zstd Bcachefs: zlib/DEFLATE, LZ4, Zstd. Currently no encoded I/O support. Cheers, David
