Merge tag 'md/3.19-fixes' of git://neil.brown.name/md
Pull two fixes for md from Neil Brown:
- Another live lock, needs backporting
- work-around false positive with new warnings.
* tag 'md/3.19-fixes' of git://neil.brown.name/md:
md/bitmap: fix a might_sleep() warning.
md/raid5: fix another livelock caused by non-aligned writes.
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index da3604e..1695ee5 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -72,6 +72,19 @@
/* this page has not been allocated yet */
spin_unlock_irq(&bitmap->lock);
+ /* It is possible that this is being called inside a
+ * prepare_to_wait/finish_wait loop from raid5c:make_request().
+ * In general it is not permitted to sleep in that context as it
+ * can cause the loop to spin freely.
+ * That doesn't apply here as we can only reach this point
+ * once with any loop.
+ * When this function completes, either bp[page].map or
+ * bp[page].hijacked. In either case, this function will
+ * abort before getting to this point again. So there is
+ * no risk of a free-spin, and so it is safe to assert
+ * that sleeping here is allowed.
+ */
+ sched_annotate_sleep();
mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
spin_lock_irq(&bitmap->lock);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c1b0d52..b98765f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3195,6 +3195,11 @@
(unsigned long long)sh->sector,
rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
}
+
+ if (rcw > disks && rmw > disks &&
+ !test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ set_bit(STRIPE_DELAYED, &sh->state);
+
/* now if nothing is locked, and if we have enough data,
* we can start a write request
*/