[dm-devel] [PATCH 2/2] realtime: avoid BUG when the list is not locked
Mikulas Patocka
mpatocka at redhat.com
Mon Nov 11 13:59:44 UTC 2019
list_bl.h would crash with BUG() if we used it without locking.
dm-snapshot uses its own locking on readltime kernels, so to avoid this
BUG, we must set LIST_BL_LOCKMASK = 0.
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Index: linux-rt-devel/include/linux/list_bl.h
===================================================================
--- linux-rt-devel.orig/include/linux/list_bl.h 2019-11-07 14:01:51.000000000 +0100
+++ linux-rt-devel/include/linux/list_bl.h 2019-11-08 10:12:49.000000000 +0100
@@ -19,7 +19,7 @@
* some fast and compact auxiliary data.
*/
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+#if (defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)) && !defined(CONFIG_PREEMPT_RT_BASE)
#define LIST_BL_LOCKMASK 1UL
#else
#define LIST_BL_LOCKMASK 0UL
@@ -161,9 +161,6 @@ static inline void hlist_bl_lock(struct
bit_spin_lock(0, (unsigned long *)b);
#else
raw_spin_lock(&b->lock);
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- __set_bit(0, (unsigned long *)b);
-#endif
#endif
}
@@ -172,9 +169,6 @@ static inline void hlist_bl_unlock(struc
#ifndef CONFIG_PREEMPT_RT_BASE
__bit_spin_unlock(0, (unsigned long *)b);
#else
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
- __clear_bit(0, (unsigned long *)b);
-#endif
raw_spin_unlock(&b->lock);
#endif
}
More information about the dm-devel
mailing list