From 914e0dc5082a335ea5e7d905e99e1a1cde001369 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 22 May 2025 23:20:40 +0800 Subject: ublk: run auto buf unregisgering in same io_ring_ctx with registering UBLK_F_AUTO_BUF_REG requires that the buffer registered automatically is unregistered in same `io_ring_ctx`, so check it explicitly. Document this requirement for UBLK_F_AUTO_BUF_REG. Drop WARN_ON_ONCE() which is triggered from userspace code path. Fixes: 99c1e4eb6a3f ("ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG") Reported-by: Caleb Sander Mateos Reviewed-by: Caleb Sander Mateos Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250522152043.399824-3-ming.lei@redhat.com Signed-off-by: Jens Axboe --- include/uapi/linux/ublk_cmd.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index c4b9942697fc..1c40632cb164 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -226,7 +226,11 @@ * * For using this feature: * - * - ublk server has to create sparse buffer table + * - ublk server has to create sparse buffer table on the same `io_ring_ctx` + * for issuing `UBLK_IO_FETCH_REQ` and `UBLK_IO_COMMIT_AND_FETCH_REQ`. + * If uring_cmd isn't issued on same `io_ring_ctx`, it is ublk server's + * responsibility to unregister the buffer by issuing `IO_UNREGISTER_IO_BUF` + * manually, otherwise this ublk request won't complete. * * - ublk server passes auto buf register data via uring_cmd's sqe->addr, * `struct ublk_auto_buf_reg` is populated from sqe->addr, please see -- cgit v1.2.3