From 02040353f4fedb823f011f27962325f328d0689f Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Tue, 6 May 2025 17:47:27 +0530 Subject: [PATCH] io_uring: enable per-io write streams Allow userspace to pass a per-I/O write stream in the SQE: __u8 write_stream; The __u8 type matches the size the filesystems and block layer support. Application can query the supported values from the block devices max_write_streams sysfs attribute. Unsupported values are ignored by file operations that do not support write streams or rejected with an error by those that support them. Reviewed-by: Hannes Reinecke Reviewed-by: Nitesh Shetty Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20250506121732.8211-7-joshi.k@samsung.com Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 4 ++++ io_uring/io_uring.c | 2 ++ io_uring/rw.c | 1 + 3 files changed, 7 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 8f1fc12bac46..50e372ea97c5 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -93,6 +93,10 @@ struct io_uring_sqe { __u16 addr_len; __u16 __pad3[1]; }; + struct { + __u8 write_stream; + __u8 __pad4[3]; + }; }; union { struct { diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index c6209fe44cb1..479205df3485 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3919,6 +3919,8 @@ static int __init io_uring_init(void) BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); BUILD_BUG_SQE_ELEM(44, __u32, file_index); BUILD_BUG_SQE_ELEM(44, __u16, addr_len); + BUILD_BUG_SQE_ELEM(44, __u8, write_stream); + BUILD_BUG_SQE_ELEM(45, __u8, __pad4[0]); BUILD_BUG_SQE_ELEM(46, __u16, __pad3[0]); BUILD_BUG_SQE_ELEM(48, __u64, addr3); BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd); diff --git a/io_uring/rw.c b/io_uring/rw.c index 039e063f7091..b8389674a747 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -276,6 +276,7 @@ static int __io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, } rw->kiocb.dio_complete = NULL; rw->kiocb.ki_flags = 0; + rw->kiocb.ki_write_stream = READ_ONCE(sqe->write_stream); if (req->ctx->flags & IORING_SETUP_IOPOLL) rw->kiocb.ki_complete = io_complete_rw_iopoll; -- 2.25.1