Add write_stream support to Write opcode
#381
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Expose the write_stream field from io_uring_sqe for IORING_OP_WRITE. Uses Option<u8> to only set the field when explicitly configured, avoiding potential issues on older kernels that don't support this feature.
Make write_stream support optional via cargo feature. Only compiles write_stream field and setter when feature is enabled, ensuring compatibility with older kernel versions.
Use cfg_attr to apply allow(dead_code) annotation only when write_stream feature is disabled. This is more targeted than module-level suppression.
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| ioprio: u16 = 0, | ||
| rw_flags: i32 = 0 | ||
| rw_flags: i32 = 0, | ||
| #[cfg_attr(not(feature = "write_stream"), allow(dead_code))] |
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I don't think this need a feature.
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I'm more than happy to remove the feature!!
I want to call this out again; I personally think not supporting old kernels is fine, but I expect some people will be kind of unhappy:
A new
write_streamfeature is used to enable this capability. This allows kernels <6.16 to still compile, while newer kernel users can enable write_stream to get the feature.
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It should work correctly on older kernels as long as the user doesn't set the flag.
We don't use a feature for every opcode flag.
src/opcode.rs
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| rw_flags: i32 = 0 | ||
| rw_flags: i32 = 0, | ||
| #[cfg_attr(not(feature = "write_stream"), allow(dead_code))] | ||
| write_stream: Option<u8> = None |
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Is Option required? can it be u8?
src/opcode.rs
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| sqe.__bindgen_anon_3.rw_flags = rw_flags as _; | ||
| #[cfg(feature = "write_stream")] | ||
| if let Some(stream) = write_stream { | ||
| sqe.__bindgen_anon_5.__bindgen_anon_2.write_stream = stream; |
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It would be nice if we had a test.
Simplify the write_stream API by changing from Option<u8> to a plain u8 with default value 0. When write_stream is 0, it is not set on the SQE. This removes the need for conditional compilation in the struct destructuring and simplifies the code.
Add a test for the write_stream feature to io-uring-test. The test verifies that write_stream=1 works correctly by performing a write and read operation.
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Resolves #380.
Expose the write_stream field from
io_uring_sqeforIORING_OP_WRITE. UsesOption<u8>to only set the field when explicitly configured.caveats
This PR has big caveats, on an otherwise very simple change:
write_streamfeature is used to enable this capability. This allows kernels <6.16 to still compile, while newer kernel users can enablewrite_streamto get the feature.write_streamfeature isn't on we got adead_codewarning, for code inside theopcode!macro. Added anallow(dead_code)there.