[PATCH] md: attempt to auto-correct read errors in raid1
On a read-error we suspend the array, then synchronously read the block from
other arrays until we find one where we can read it. Then we try writing the
good data back everywhere and make sure it works. If any write or subsequent
read fails, only then do we fail the device out of the array.
To be able to suspend the array, we need to also keep track of how many
requests are queued for handling by raid1d.
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 c556742..cbe4238 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -46,6 +46,7 @@
spinlock_t resync_lock;
int nr_pending;
int nr_waiting;
+ int nr_queued;
int barrier;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
@@ -57,6 +58,8 @@
struct pool_info *poolinfo;
+ struct page *tmppage;
+
mempool_t *r1bio_pool;
mempool_t *r1buf_pool;
};