Merge the hotpath-rs wall-time instrumentation from the backlog#936 analysis worktree behind an opt-in 'hotpath' cargo feature, keeping the default build at zero overhead and zero dependency.
- hotpath is an optional dependency everywhere (dep:hotpath feature syntax); the default dependency tree contains no hotpath crate at all
- 40+ measurement points across S3 handlers, ECStore/SetDisks object and multipart ops, erasure encode/decode, bitrot, LocalDisk I/O, FileMeta codec, and HashReader
- attribute sites use #[cfg_attr(feature = "hotpath", hotpath::measure)]; async_trait bodies use per-crate hp_guard! macros (ecstore + rustfs bin); rio gates measure_block! behind hp_measure_block!
- feature chain: rustfs -> rustfs-ecstore -> rustfs-rio / rustfs-filemeta, each crate owning its own gate
- hotpath-alloc is intentionally not wired up (hotpath 0.21.x TLS panic on cross-thread guard drop under tokio, see backlog#935); mimalloc stays the unconditional global allocator
- docs/development/hotpath-profiling.md documents building, HOTPATH_* env vars, SIGTERM report flow, and how to reproduce the backlog#936 timing reports
Refs: https://github.com/rustfs/backlog/issues/935 (HP-14, item 2), https://github.com/rustfs/backlog/issues/936
Co-authored-by: heihutu <heihutu@gmail.com>
The codec streaming GET reader divides by erasure.block_size in
build_codec_streaming_part_reader without validating the erasure
dimensions, unlike the legacy multipart path which already rejects
block_size==0 / data_shards==0. FileInfo::is_valid() does not check
block_size, so corrupted on-disk metadata (block_size==0, data_blocks>0)
passes validation and panics the read task with a divide-by-zero.
Add Erasure::has_valid_dimensions() and reject invalid dimensions at the
codec streaming entry before any disk access, mirroring the legacy guard
(which now reuses the same predicate).
Refs backlog#868 (868-1).
Zhengchao An