dm: sysfs skip output when device is being destroyed
Do not process sysfs attributes when device is being destroyed.
Otherwise code can cause
BUG_ON(test_bit(DMF_FREEING, &md->flags));
in dm_put() call.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 48db308..f1db689 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1777,6 +1777,10 @@
if (&md->kobj != kobj)
return NULL;
+ if (test_bit(DMF_FREEING, &md->flags) ||
+ test_bit(DMF_DELETING, &md->flags))
+ return NULL;
+
dm_get(md);
return md;
}