1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 57d6abd497ef..d3d3568b4fb1 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -46,6 +46,20 @@
  */
 #define NR_RAID1_BIOS 256
 
+/* when we get a read error on a read-only array, we redirect to another
+ * device without failing the first device, or trying to over-write to
+ * correct the read error.  To keep track of bad blocks on a per-bio
+ * level, we store IO_BLOCKED in the appropriate 'bios' pointer
+ */
+#define IO_BLOCKED ((struct bio *)1)
+/* When we successfully write to a known bad-block, we need to remove the
+ * bad-block marking which must be done from process context.  So we record
+ * the success by setting devs[n].bio to IO_MADE_GOOD
+ */
+#define IO_MADE_GOOD ((struct bio *)2)
+
+#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
+
 /* When there are this many requests queue to be written by
  * the raid1 thread, we become 'congested' to provide back-pressure
  * for writeback.