man/io_uring_enter.2: make it clear that chains terminate at submit
The man page does state that:
"This flag has no effect on previous SQE submissions [...]"
but add some more verbiage to make it absolutely clear that chains
cannot persist across submission boundaries.
Link:
@@ -1047,12 +1047,14 @@ submitted SQEs have completed, and new SQEs will not be started before this
one completes. Available since 5.2.
.TP
.B IOSQE_IO_LINK
-When this flag is specified, it forms a link with the next SQE in the
-submission ring. That next SQE will not be started before this one completes.
-This, in effect, forms a chain of SQEs, which can be arbitrarily long. The tail
-of the chain is denoted by the first SQE that does not have this flag set.
-This flag has no effect on previous SQE submissions, nor does it impact SQEs
-that are outside of the chain tail. This means that multiple chains can be
+When this flag is specified, the SQE forms a link with the next SQE in the
+submission ring. That next SQE will not be started before the previous request
+completes. This, in effect, forms a chain of SQEs, which can be arbitrarily
+long. The tail of the chain is denoted by the first SQE that does not have this
+flag set. Chains are not supported across submission boundaries. EVen if the
+last SQE in a submission has this flag set, it will still terminate the current
+chain. This flag has no effect on previous SQE submissions, nor does it impact
+SQEs that are outside of the chain tail. This means that multiple chains can be
executing in parallel, or chains and individual SQEs. Only members inside the
chain are serialized. A chain of SQEs will be broken, if any request in that
chain ends in error. io_uring considers any unexpected result an error. This
