The netfs_io_stream::front member is meant to point to the subrequest
currently being collected on a stream, but it isn't actually used this way
by direct write (which mostly ignores it). However, there's a tracepoint
which looks at it. Further, stream->front is actually redundant with
stream->subrequests.next.
Fix the potential problem in the direct code by just removing the member
and using stream->subrequests.next instead, thereby also simplifying the
code.
Fixes: a0b4c7a491 ("netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence")
Reported-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/4158599.1774426817@warthog.procyon.org.uk
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
0e764b9d46