rust: Some doc and misc tweaks

Prep for a first publishing of the crates.

Signed-off-by: Colin Walters <[email protected]>

rust/composefs-core/Cargo.toml

@@ -25,7 +25,7 @@ v1_0_4 = ["composefs-sys/v1_0_4"]
 [dependencies]
 anyhow = "1.0"
 libc = "0.2"
-composefs-sys = { path = "../composefs-sys" }
+composefs-sys = { version = "0.1.0", path = "../composefs-sys" }
 
 [dev-dependencies]
 tar = "0.4.38"

rust/composefs-core/src/fsverity.rs

@@ -1,7 +1,6 @@
-//! # Bindings for computing fsverity
+//! # Bindings for fsverity
 //!
-//! This collection of APIs is for computing fsverity digests as
-//! used by composefs.
+//! This collection of APIs is for fsverity as used by composefs.
 
 use std::os::fd::{AsRawFd, BorrowedFd};
 

rust/composefs-core/src/lib.rs

@@ -1,7 +1,11 @@
 //! # Rust composefs library
 //!
-//! This crate builds on top of the core composefs tooling, adding a Rust
-//! API especially oriented around OCI container images.
+//! This crate builds on top of the core composefs tooling; it currently requires
+//! both the `libcomposefs` C library as well as the external executables
+//! `mkcomposefs` and `composefs-info`.
+//!
+//! The core functionality exposed at the moment is just support for creating
+//! and parsing composefs "superblock" entries.
 
 // See https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html
 #![deny(missing_docs)]
@@ -25,7 +29,10 @@ pub mod mkcomposefs;
 
 pub mod fsverity;
 
-/// Parse a composefs superblock.
+/// Parse a composefs superblock.  The provided callback will be invoked
+/// for each entry in the target image, containing exactly one parsed entry.
+///
+/// This function depends on an external `composefs-info` binary currently.
 pub fn dump<F>(f: File, mut callback: F) -> Result<()>
 where
     F: FnMut(&'_ Entry) -> Result<()>,