[95/98] [SCSI] Enable retries for SYNCRONIZE_CACHE commands to fix I/O error

From: Greg KH
Date: Mon May 10 2010 - 19:11:52 EST


2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Hannes Reinecke <hare@xxxxxxx>

commit c213e1407be6b04b144794399a91472e0ef92aec upstream.

Some arrays are giving I/O errors with ext3 filesystems when
SYNCHRONIZE_CACHE gets a UNIT_ATTENTION. What is happening is that
these commands have no retries, so the UNIT_ATTENTION causes the
barrier to fail. We should be enable retries here to clear any
transient error and allow the barrier to succeed.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/scsi/sd.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -971,6 +971,7 @@ static void sd_prepare_flush(struct requ
{
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = SD_TIMEOUT;
+ rq->retries = SD_MAX_RETRIES;
rq->cmd[0] = SYNCHRONIZE_CACHE;
rq->cmd_len = 10;
}


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