[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, 3 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3824e754ca1d..fd874b846dc1 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -830,7 +830,7 @@ static int sd_setup_write_same_cmnd(struct scsi_device *sdp, struct request *rq)
 
 static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
 {
-        rq->timeout = SD_FLUSH_TIMEOUT;
+        rq->timeout *= SD_FLUSH_TIMEOUT_MULTIPLIER;
         rq->retries = SD_MAX_RETRIES;
         rq->cmd[0] = SYNCHRONIZE_CACHE;
         rq->cmd_len = 10;
@@ -1434,6 +1434,8 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
 {
         int retries, res;
         struct scsi_device *sdp = sdkp->device;
+        const int timeout = sdp->request_queue->rq_timeout
+                * SD_FLUSH_TIMEOUT_MULTIPLIER;
         struct scsi_sense_hdr sshdr;
 
         if (!scsi_device_online(sdp))
@@ -1448,8 +1450,8 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
                  * flush everything.
                  */
                 res = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0,
-                                             &sshdr, SD_FLUSH_TIMEOUT,
-                                             SD_MAX_RETRIES, NULL, REQ_PM);
+                                             &sshdr, timeout, SD_MAX_RETRIES,
+                                             NULL, REQ_PM);
                 if (res == 0)
                         break;
         }