From 4e5314b56a7ea11c7a5f2b8418992b2f49648a25 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 8 Nov 2005 21:39:22 -0800 Subject: [PATCH] md: better handling of readerrors with raid5. This patch changes the behaviour of raid5 when it gets a read error. Instead of just failing the device, it tried to find out what should have been there, and writes it over the bad block. For some media-errors, this has a reasonable chance of fixing the error. If the write succeeds, and a subsequent read succeeds as well, raid5 decided the address is OK and conitnues. Instead of failing a drive on read-error, we attempt to re-write the block, and then re-read. If that all works, we allow the device to remain in the array. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/raid/raid5.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/raid/raid5.h') diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h index 176fc653c284..f025ba6fb14c 100644 --- a/include/linux/raid/raid5.h +++ b/include/linux/raid/raid5.h @@ -154,6 +154,8 @@ struct stripe_head { #define R5_Wantwrite 5 #define R5_Syncio 6 /* this io need to be accounted as resync io */ #define R5_Overlap 7 /* There is a pending overlapping request on this block */ +#define R5_ReadError 8 /* seen a read error here recently */ +#define R5_ReWrite 9 /* have tried to over-write the readerror */ /* * Write method -- cgit v1.2.3-59-g8ed1b