[PATCH 2/6] libmultipath: directio: don't reset ct->running after io_cancel()

[mwilck@xxxxxxxx]

From: Martin Wilck <mwilck@xxxxxxxx>

io_cancel() never succeeds, and even if it did, io_getevents() must
still be called to reclaim the IO resources from the kernel.
Don't pretend the opposite by resetting ct->running, or freeing the
memory, before io_getevents() has indicated that the request is finished.

Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
 libmultipath/checkers/directio.c | 13 ++-----------
 tests/directio.c                 | 10 +---------
 2 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/libmultipath/checkers/directio.c b/libmultipath/checkers/directio.c
index 25b2383..71ce4cb 100644
--- a/libmultipath/checkers/directio.c
+++ b/libmultipath/checkers/directio.c
@@ -216,7 +216,6 @@ out:
 void libcheck_free (struct checker * c)
 {
 	struct directio_context * ct = (struct directio_context *)c->context;
-	struct io_event event;
 	long flags;
 
 	if (!ct)
@@ -232,9 +231,7 @@ void libcheck_free (struct checker * c)
 		}
 	}
 
-	if (ct->running &&
-	    (ct->req->state != PATH_PENDING ||
-	     io_cancel(ct->aio_grp->ioctx, &ct->req->io, &event) == 0))
+	if (ct->running && ct->req->state != PATH_PENDING)
 		ct->running = 0;
 	if (!ct->running) {
 		free(ct->req->buf);
@@ -351,13 +348,7 @@ check_state(int fd, struct directio_context *ct, int sync, int timeout_secs)
 
 		LOG(3, "abort check on timeout");
 
-		r = io_cancel(ct->aio_grp->ioctx, &ct->req->io, &event);
-		/*
-		 * Only reset ct->running if we really
-		 * could abort the pending I/O
-		 */
-		if (!r)
-			ct->running = 0;
+		io_cancel(ct->aio_grp->ioctx, &ct->req->io, &event);
 		rc = PATH_DOWN;
 	} else {
 		LOG(4, "async io pending");
diff --git a/tests/directio.c b/tests/directio.c
index db9643e..b340498 100644
--- a/tests/directio.c
+++ b/tests/directio.c
@@ -501,13 +501,8 @@ static void test_free_with_pending(void **state)
 	check_aio_grp(aio_grp, 2, 0);
         libcheck_free(&c[0]);
 	check_aio_grp(aio_grp, 1, 0);
-        will_return(__wrap_io_cancel, 0);
         libcheck_free(&c[1]);
-#ifdef DIO_TEST_DEV
-	check_aio_grp(aio_grp, 1, 1); /* real cancel doesn't remove request */
-#else
-        check_aio_grp(aio_grp, 0, 0);
-#endif
+	check_aio_grp(aio_grp, 1, 1); /* cancel doesn't remove request */
         do_libcheck_reset(1);
 }
 
@@ -533,7 +528,6 @@ static void test_orphaned_aio_group(void **state)
 	assert_int_equal(i, 1);
 	for (i = 0; i < AIO_GROUP_SIZE; i++) {
 		assert_true(is_checker_running(&c[i]));
-		will_return(__wrap_io_cancel, -1);
 		if (i == AIO_GROUP_SIZE - 1) {
 			/* remove the orphaned group and create a new one */
 			will_return(__wrap_io_destroy, 0);
@@ -637,7 +631,6 @@ static void test_orphan_checker_cleanup(void **state)
 	aio_grp = get_aio_grp(c);
 	return_io_getevents_none();
 	do_check_state(&c[0], 0, 30, PATH_PENDING);
-	will_return(__wrap_io_cancel, -1);
 	check_aio_grp(aio_grp, 2, 0);
 	libcheck_free(&c[0]);
 	check_aio_grp(aio_grp, 2, 1);
@@ -662,7 +655,6 @@ static void test_orphan_reset_cleanup(void **state)
 	orphan_aio_grp = get_aio_grp(&c);
 	return_io_getevents_none();
 	do_check_state(&c, 0, 30, PATH_PENDING);
-	will_return(__wrap_io_cancel, -1);
 	check_aio_grp(orphan_aio_grp, 1, 0);
 	libcheck_free(&c);
 	check_aio_grp(orphan_aio_grp, 1, 1);
-- 
2.42.0