md/bitmap: remove rcu annotation from pointer arithmetic.
Evaluating "&mddev->disks" is simple pointer arithmetic, so
it does not need 'rcu' annotations - no dereferencing is happening.
Also enhance the comment to explain that 'rdev' in that case
is not actually a pointer to an rdev.
Reported-by: Patrick Marlier <patrick.marlier@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 2bc56e2..135a090 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -177,11 +177,16 @@
* nr_pending is 0 and In_sync is clear, the entries we return will
* still be in the same position on the list when we re-enter
* list_for_each_entry_continue_rcu.
+ *
+ * Note that if entered with 'rdev == NULL' to start at the
+ * beginning, we temporarily assign 'rdev' to an address which
+ * isn't really an rdev, but which can be used by
+ * list_for_each_entry_continue_rcu() to find the first entry.
*/
rcu_read_lock();
if (rdev == NULL)
/* start at the beginning */
- rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set);
+ rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
else {
/* release the previous rdev and start from there. */
rdev_dec_pending(rdev, mddev);