[SCSI] Derive the FLUSH_TIMEOUT from the basic I/O timeout

Rather than having a separate constant for specifying the timeout on FLUSH
operations, use the basic I/O timeout value that is already configurable
on a per target basis to derive the FLUSH timeout. Looking at the current
definitions of these timeout values, the FLUSH operation is supposed to have
a value that is twice the normal timeout value. This patch preserves this
relationship while leveraging the flexibility of specifying the I/O timeout.

Based on a prior patch by KY Srinivasan <kys@microsoft.com>

Reviewed-by: KY Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 7a049de22051..26895ff247c5 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -13,7 +13,11 @@
  */
 #define SD_TIMEOUT              (30 * HZ)
 #define SD_MOD_TIMEOUT          (75 * HZ)
-#define SD_FLUSH_TIMEOUT        (60 * HZ)
+/*
+ * Flush timeout is a multiplier over the standard device timeout which is
+ * user modifiable via sysfs but initially set to SD_TIMEOUT
+ */
+#define SD_FLUSH_TIMEOUT_MULTIPLIER     2
 #define SD_WRITE_SAME_TIMEOUT   (120 * HZ)
 
 /*