Add a new sendzc flag, IORING_SENDZC_COPY_TAG. When set and the request
flushing a notification, it'll set the notification tag to
sqe->user_data. This adds a bit more flexibility allowing to specify
notification tags on per-request basis.
One use cases is combining the new flag with IOSQE_CQE_SKIP_SUCCESS,
so either the request fails and we expect an CQE with a failure and no
notification, or it succedees, then there will be no request completion
but only a zc notification with an overriden tag. In other words, in the
described scheme it posts only one CQE with user_data set to the current
requests sqe->user_data.
note 1: the flat has no effect if nothing is flushed, e.g. there was
no IORING_SENDZC_FLUSH or the request failed.
note 2: copying sqe->user_data may be not ideal, but we don't have
extra space in SQE to keep a second tag/user_data.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 9 +++++++--
include/uapi/linux/io_uring.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f5fe2ab5622a..08c98a4d9bd2 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6581,7 +6581,8 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags)
return 0;
}
-#define IO_SENDZC_VALID_FLAGS (IORING_SENDZC_FIXED_BUF|IORING_SENDZC_FLUSH)
+#define IO_SENDZC_VALID_FLAGS (IORING_SENDZC_FIXED_BUF | IORING_SENDZC_FLUSH | \
+ IORING_SENDZC_OVERRIDE_TAG)
static int io_sendzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
@@ -6686,7 +6687,11 @@ static int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
ret = sock_sendmsg(sock, &msg);
if (likely(ret >= min_ret)) {
- if (req->msgzc.zc_flags & IORING_SENDZC_FLUSH)
+ unsigned zc_flags = req->msgzc.zc_flags;
+
+ if (zc_flags & IORING_SENDZC_OVERRIDE_TAG)
+ notif->tag = req->cqe.user_data;
+ if (zc_flags & IORING_SENDZC_FLUSH)
io_notif_slot_flush_submit(notif_slot, 0);
} else {
if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 7d77d90a5f8a..7533387f25d3 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -280,6 +280,7 @@ enum {
enum {
IORING_SENDZC_FIXED_BUF = (1U << 0),
IORING_SENDZC_FLUSH = (1U << 1),
+ IORING_SENDZC_OVERRIDE_TAG = (1U << 2),
};
/*
--
2.36.1
