Merge: io_uring: enable per-io write streams

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/7523

io_uring: enable per-io write streams

JIRA: https://issues.redhat.com/browse/RHEL-122870

This is actually one bug fix for initializing kiocb.ki_write_stream,
otherwise it may fail blktests block/035.

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Approved-by: Brian Foster <bfoster@redhat.com>
Approved-by: John Meneghini <jmeneghi@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

include/uapi/linux/io_uring.h

@@ -92,6 +92,10 @@ struct io_uring_sqe {
 			__u16	addr_len;
 			__u16	__pad3[1];
 		};
+		struct {
+			__u8	write_stream;
+			__u8	__pad4[3];
+		};
 	};
 	union {
 		struct {

io_uring/io_uring.c

@@ -3895,6 +3895,8 @@ 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);

io_uring/rw.c

@@ -291,6 +291,7 @@ 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;