github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

rust: block: implement Send and Sync for TagSet

Browse Source 
`TagSet` never implemented `Send` or `Sync`. This did not matter until
commit "rust: block: fix `Send` bound for `GenDisk`" made `GenDisk: Send`
depend on `Arc<TagSet<T>>: Send`, which in turn requires `TagSet<T>: Send +
Sync`. With that bound unsatisfiable, `GenDisk` is never `Send`, and the
rnull driver fails to build once configfs requires `GroupOperations::Child:
Send`.

`TagSet` owns no data typed by `T`. It only wraps the C `struct
blk_mq_tag_set`, which can be dropped from any thread by calling
`blk_mq_free_tag_set`. Thus, implement `Send` and `Sync` for `TagSet`
unconditionally.

Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/r/d1381ed8-eab8-4fd7-8b15-1e94876d7099@leemhuis.info
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260930-tag-set-send-sync-v1-1-51acdb36f4bb@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Andreas Hindborg 2026-09-30 21:43:55 +02:00 committed by Jens Axboe
parent 67b7a2728e
commit 06dad60393
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
rust/kernel/block/mq/tag_set.rs
View File

@ -83,3 +83,10 @@ fn drop(self: Pin<&mut Self>) {
unsafe { bindings::blk_mq_free_tag_set(self.inner.get()) };
}
}
// SAFETY: It is safe to transfer ownership of `TagSet` between threads.
unsafe impl<T: Operations> Send for TagSet<T> {}
// SAFETY: It is safe to share `&TagSet` across threads. `TagSet` exposes no
// `&self` methods that mutate the contained `blk_mq_tag_set`.
unsafe impl<T: Operations> Sync for TagSet<T> {}