md/raid5: STRIPE_ACTIVE has lock semantics, add barriers
All updates that occur under STRIPE_ACTIVE should be globally visible
when STRIPE_ACTIVE clears. test_and_set_bit() implies a barrier, but
clear_bit() does not.
This is suitable for 3.1-stable.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 318bdae..297e260 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3110,7 +3110,7 @@
struct r5dev *pdev, *qdev;
clear_bit(STRIPE_HANDLE, &sh->state);
- if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) {
+ if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
/* already being handled, ensure it gets handled
* again when current action finishes */
set_bit(STRIPE_HANDLE, &sh->state);
@@ -3375,7 +3375,7 @@
return_io(s.return_bi);
- clear_bit(STRIPE_ACTIVE, &sh->state);
+ clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
}
static void raid5_activate_delayed(struct r5conf *conf)