[PATCH] md: handle errors when read-only
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h
index cbe4238..9d5494a 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -109,6 +109,13 @@
/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
};
+/* 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)
+
/* bits for r1bio.state */
#define R1BIO_Uptodate 0
#define R1BIO_IsSync 1