io_send_zc() guards its call to io_send_zc_import() with if (!done_io)
in an attempt to avoid calling it redundantly on the same req. However,
if the initial non-blocking issue returns -EAGAIN, done_io will stay 0.
This causes the subsequent issue to unnecessarily re-import the buffer.
Add an explicit flag "imported" to io_sr_msg to track if its buffer has
already been imported. Clear the flag in io_send_zc_prep(). Call
io_send_zc_import() and set the flag in io_send_zc() if it is unset.
Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
Fixes: 54cdcca05abd ("io_uring/net: switch io_send() and io_send_zc() to using io_async_msghdr")
---
io_uring/net.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/io_uring/net.c b/io_uring/net.c
index 6d13d378358b..a29893d567b8 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -74,10 +74,11 @@ struct io_sr_msg {
unsigned nr_multishot_loops;
u16 flags;
/* initialised and used only by !msg send variants */
u16 buf_group;
bool retry;
+ bool imported; /* only for io_send_zc */
void __user *msg_control;
/* used only for send zerocopy */
struct io_kiocb *notif;
};
@@ -1222,10 +1223,11 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *notif;
zc->done_io = 0;
zc->retry = false;
+ zc->imported = false;
req->flags |= REQ_F_POLL_NO_LAZY;
if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
return -EINVAL;
/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
@@ -1369,11 +1371,12 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
if (!(req->flags & REQ_F_POLLED) &&
(zc->flags & IORING_RECVSEND_POLL_FIRST))
return -EAGAIN;
- if (!zc->done_io) {
+ if (!zc->imported) {
+ zc->imported = true;
ret = io_send_zc_import(req, issue_flags);
if (unlikely(ret))
return ret;
}
--
2.45.2
