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-rw-r--r--io_uring/io_uring.h8
-rw-r--r--io_uring/net.c55
-rw-r--r--io_uring/poll.c49
-rw-r--r--io_uring/poll.h9
-rw-r--r--io_uring/rw.c10
5 files changed, 92 insertions, 39 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 04e33f25919c..d5495710c178 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -15,12 +15,18 @@
#include <trace/events/io_uring.h>
#endif
-
enum {
IOU_OK = 0,
IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED,
/*
+ * Requeue the task_work to restart operations on this request. The
+ * actual value isn't important, should just be not an otherwise
+ * valid error code, yet less than -MAX_ERRNO and valid internally.
+ */
+ IOU_REQUEUE = -3072,
+
+ /*
* Intended only when both IO_URING_F_MULTISHOT is passed
* to indicate to the poll runner that multishot should be
* removed and the result is set on req->cqe.res.
diff --git a/io_uring/net.c b/io_uring/net.c
index 75d494dad7e2..161622029147 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -60,6 +60,7 @@ struct io_sr_msg {
unsigned len;
unsigned done_io;
unsigned msg_flags;
+ unsigned nr_multishot_loops;
u16 flags;
/* initialised and used only by !msg send variants */
u16 addr_len;
@@ -70,6 +71,13 @@ struct io_sr_msg {
struct io_kiocb *notif;
};
+/*
+ * Number of times we'll try and do receives if there's more data. If we
+ * exceed this limit, then add us to the back of the queue and retry from
+ * there. This helps fairness between flooding clients.
+ */
+#define MULTISHOT_MAX_RETRY 32
+
static inline bool io_check_multishot(struct io_kiocb *req,
unsigned int issue_flags)
{
@@ -611,6 +619,7 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
sr->done_io = 0;
+ sr->nr_multishot_loops = 0;
return 0;
}
@@ -645,23 +654,35 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
return true;
}
- if (!mshot_finished) {
- if (io_fill_cqe_req_aux(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
- *ret, cflags | IORING_CQE_F_MORE)) {
- io_recv_prep_retry(req);
- /* Known not-empty or unknown state, retry */
- if (cflags & IORING_CQE_F_SOCK_NONEMPTY ||
- msg->msg_inq == -1)
+ if (mshot_finished)
+ goto finish;
+
+ /*
+ * Fill CQE for this receive and see if we should keep trying to
+ * receive from this socket.
+ */
+ if (io_fill_cqe_req_aux(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
+ *ret, cflags | IORING_CQE_F_MORE)) {
+ struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+ int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;
+
+ io_recv_prep_retry(req);
+ /* Known not-empty or unknown state, retry */
+ if (cflags & IORING_CQE_F_SOCK_NONEMPTY || msg->msg_inq == -1) {
+ if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY)
return false;
- if (issue_flags & IO_URING_F_MULTISHOT)
- *ret = IOU_ISSUE_SKIP_COMPLETE;
- else
- *ret = -EAGAIN;
- return true;
+ /* mshot retries exceeded, force a requeue */
+ sr->nr_multishot_loops = 0;
+ mshot_retry_ret = IOU_REQUEUE;
}
- /* Otherwise stop multishot but use the current result. */
+ if (issue_flags & IO_URING_F_MULTISHOT)
+ *ret = mshot_retry_ret;
+ else
+ *ret = -EAGAIN;
+ return true;
}
-
+ /* Otherwise stop multishot but use the current result. */
+finish:
io_req_set_res(req, *ret, cflags);
if (issue_flags & IO_URING_F_MULTISHOT)
@@ -902,6 +923,7 @@ retry_multishot:
if (!buf)
return -ENOBUFS;
sr->buf = buf;
+ sr->len = len;
}
ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
@@ -1350,7 +1372,7 @@ retry:
* has already been done
*/
if (issue_flags & IO_URING_F_MULTISHOT)
- ret = IOU_ISSUE_SKIP_COMPLETE;
+ return IOU_ISSUE_SKIP_COMPLETE;
return ret;
}
if (ret == -ERESTARTSYS)
@@ -1375,7 +1397,8 @@ retry:
ret, IORING_CQE_F_MORE))
goto retry;
- return -ECANCELED;
+ io_req_set_res(req, ret, 0);
+ return IOU_STOP_MULTISHOT;
}
int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
diff --git a/io_uring/poll.c b/io_uring/poll.c
index d59b74a99d4e..7513afc7b702 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -226,8 +226,29 @@ enum {
IOU_POLL_NO_ACTION = 1,
IOU_POLL_REMOVE_POLL_USE_RES = 2,
IOU_POLL_REISSUE = 3,
+ IOU_POLL_REQUEUE = 4,
};
+static void __io_poll_execute(struct io_kiocb *req, int mask)
+{
+ unsigned flags = 0;
+
+ io_req_set_res(req, mask, 0);
+ req->io_task_work.func = io_poll_task_func;
+
+ trace_io_uring_task_add(req, mask);
+
+ if (!(req->flags & REQ_F_POLL_NO_LAZY))
+ flags = IOU_F_TWQ_LAZY_WAKE;
+ __io_req_task_work_add(req, flags);
+}
+
+static inline void io_poll_execute(struct io_kiocb *req, int res)
+{
+ if (io_poll_get_ownership(req))
+ __io_poll_execute(req, res);
+}
+
/*
* All poll tw should go through this. Checks for poll events, manages
* references, does rewait, etc.
@@ -309,6 +330,8 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts)
int ret = io_poll_issue(req, ts);
if (ret == IOU_STOP_MULTISHOT)
return IOU_POLL_REMOVE_POLL_USE_RES;
+ else if (ret == IOU_REQUEUE)
+ return IOU_POLL_REQUEUE;
if (ret < 0)
return ret;
}
@@ -331,8 +354,12 @@ void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts)
int ret;
ret = io_poll_check_events(req, ts);
- if (ret == IOU_POLL_NO_ACTION)
+ if (ret == IOU_POLL_NO_ACTION) {
+ return;
+ } else if (ret == IOU_POLL_REQUEUE) {
+ __io_poll_execute(req, 0);
return;
+ }
io_poll_remove_entries(req);
io_poll_tw_hash_eject(req, ts);
@@ -364,26 +391,6 @@ void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts)
}
}
-static void __io_poll_execute(struct io_kiocb *req, int mask)
-{
- unsigned flags = 0;
-
- io_req_set_res(req, mask, 0);
- req->io_task_work.func = io_poll_task_func;
-
- trace_io_uring_task_add(req, mask);
-
- if (!(req->flags & REQ_F_POLL_NO_LAZY))
- flags = IOU_F_TWQ_LAZY_WAKE;
- __io_req_task_work_add(req, flags);
-}
-
-static inline void io_poll_execute(struct io_kiocb *req, int res)
-{
- if (io_poll_get_ownership(req))
- __io_poll_execute(req, res);
-}
-
static void io_poll_cancel_req(struct io_kiocb *req)
{
io_poll_mark_cancelled(req);
diff --git a/io_uring/poll.h b/io_uring/poll.h
index ff4d5d753387..1dacae9e816c 100644
--- a/io_uring/poll.h
+++ b/io_uring/poll.h
@@ -24,6 +24,15 @@ struct async_poll {
struct io_poll *double_poll;
};
+/*
+ * Must only be called inside issue_flags & IO_URING_F_MULTISHOT, or
+ * potentially other cases where we already "own" this poll request.
+ */
+static inline void io_poll_multishot_retry(struct io_kiocb *req)
+{
+ atomic_inc(&req->poll_refs);
+}
+
int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_poll_add(struct io_kiocb *req, unsigned int issue_flags);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 118cc9f1cf16..d5e79d9bdc71 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -18,6 +18,7 @@
#include "opdef.h"
#include "kbuf.h"
#include "rsrc.h"
+#include "poll.h"
#include "rw.h"
struct io_rw {
@@ -962,8 +963,15 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags)
if (io_fill_cqe_req_aux(req,
issue_flags & IO_URING_F_COMPLETE_DEFER,
ret, cflags | IORING_CQE_F_MORE)) {
- if (issue_flags & IO_URING_F_MULTISHOT)
+ if (issue_flags & IO_URING_F_MULTISHOT) {
+ /*
+ * Force retry, as we might have more data to
+ * be read and otherwise it won't get retried
+ * until (if ever) another poll is triggered.
+ */
+ io_poll_multishot_retry(req);
return IOU_ISSUE_SKIP_COMPLETE;
+ }
return -EAGAIN;
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-19 22:00:10 +0000