fix(runtime): remove tokio io-uring feature and add regression guard (#4364)

Drop the [target.'cfg(target_os = "linux")'.dependencies] tokio
"io-uring" feature from 6 crates and the rustfs binary. Because
.cargo/config.toml enables --cfg tokio_unstable globally, this feature
switched every Linux build's file I/O onto tokio's io_uring runtime
backend. Restricted Linux environments (Docker default seccomp, gVisor,
proot, old kernels) reject io_uring_setup with EACCES/ENOSYS, which
tokio surfaced as PermissionDenied and RustFS reported as
DiskAccessDenied at startup.

Add scripts/check_no_tokio_io_uring.sh so the feature cannot silently
return: it fails on any tokio dependency line enabling "io-uring", while
still allowing a future application-level io-uring crate dependency.
Wire it into make pre-commit/pre-pr/dev-check and CI.

Tracking: rustfs/backlog#890 (parent rustfs/backlog#897)

Co-authored-by: heihutu <heihutu@gmail.com>

crates/ecstore/Cargo.toml

@@ -171,7 +171,3 @@ harness = false
 
 [lib]
 doctest = false
-
-# io-uring is Linux-only. Scope the feature to Linux targets.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }

crates/io-core/Cargo.toml

@@ -34,13 +34,6 @@ tokio = { workspace = true, features = ["io-util", "fs", "rt", "sync"] }
 memmap2 = { workspace = true }
 rustfs-io-metrics = { workspace = true }
 
-# Enable tokio's io_uring-based runtime backend on Linux.
-# Note: this is a tokio runtime feature, not application-level io_uring usage.
-# See the Tokio 1.52.0 release notes and tokio-rs/tokio#7907 for the upstream
-# runtime feature context.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }
-
 [dev-dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }
 

crates/kms/Cargo.toml

@@ -70,7 +70,3 @@ temp-env = { workspace = true }
 
 [features]
 default = []
-
-# io-uring is Linux-only. Scope the feature to Linux targets.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }

crates/protocols/Cargo.toml

@@ -136,7 +136,3 @@ tokio = { workspace = true, features = ["test-util", "macros", "rt"] }
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
-
-# io-uring is Linux-only. Scope the feature to Linux targets.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }

crates/scanner/Cargo.toml

@@ -62,7 +62,3 @@ tokio = { workspace = true, features = ["test-util"] }
 
 [lib]
 doctest = false
-
-# io-uring is Linux-only. Scope the feature to Linux targets.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }

crates/zip/Cargo.toml

@@ -54,7 +54,3 @@ tempfile = { workspace = true }
 
 [lints]
 workspace = true
-
-# io-uring is Linux-only. Scope the feature to Linux targets.
-[target.'cfg(target_os = "linux")'.dependencies]
-tokio = { workspace = true, features = ["io-uring"] }