Problem was found during reshaping 2 volumes /raid0 and raid5/ in container.
Sometimes mdmon throws core dump due to NULL pointer exception.
Problem occurs in scenario:
- managemon: is about spare activation (degraded raid4 volume == raid0 under takeover)
- managemon: detect level change and signals monitor (manage_member() calls replace_array())
- monitor: detects transition raid4/5->raid0 and sets a->container to NULL
to indicate array deactivation
- managemon : continues his work and tries to activate spare (a->check_degraded is set).
NULL pointer is passed to metadata handler activate_spare()
Core dump is generated.
To resolve this situation managemon (after monitor kick) checks again
a->container pointer to learn if current array is not to be deactivated.
Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
---
managemon.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/managemon.c b/managemon.c
index d020f82..3540dac 100644
--- a/managemon.c
+++ b/managemon.c
@@ -475,6 +475,12 @@ static void manage_member(struct mdstat_ent *mdstat,
}
}
+ /* we are after monitor kick,
+ * so container field can be cleared - check it again
+ */
+ if (a->container == NULL)
+ return;
+
/* We don't check the array while any update is pending, as it
* might container a change (such as a spare assignment) which
* could affect our decisions.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
