[SCSI] expose eh_timed_out to the host template

It looks like megaraid_sas at least needs this to throttle its commands
as they begin to time out.  The code keeps the existing transport
template use of eh_timed_out (and allows the transport to override the
host if they both have this callback).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 23 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index b8edcf5b5451..7a1a1bb1341e 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -184,10 +184,19 @@ int scsi_delete_timer(struct scsi_cmnd *scmd)
  **/
 void scsi_times_out(struct scsi_cmnd *scmd)
 {
+        enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+
         scsi_log_completion(scmd, TIMEOUT_ERROR);
 
         if (scmd->device->host->transportt->eh_timed_out)
-                switch (scmd->device->host->transportt->eh_timed_out(scmd)) {
+                eh_timed_out = scmd->device->host->transportt->eh_timed_out;
+        else if (scmd->device->host->hostt->eh_timed_out)
+                eh_timed_out = scmd->device->host->hostt->eh_timed_out;
+        else
+                eh_timed_out = NULL;
+
+        if (eh_timed_out)
+                switch (eh_timed_out(scmd)) {
                 case EH_HANDLED:
                         __scsi_done(scmd);
                         return;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 965b6b8ffec5..68f461b7a835 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -326,6 +326,19 @@ struct scsi_host_template {
         int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
 
         /*
+         * This is an optional routine that allows the transport to become
+         * involved when a scsi io timer fires. The return value tells the
+         * timer routine how to finish the io timeout handling:
+         * EH_HANDLED:          I fixed the error, please complete the command
+         * EH_RESET_TIMER:      I need more time, reset the timer and
+         *                      begin counting again
+         * EH_NOT_HANDLED       Begin normal error recovery
+         *
+         * Status: OPTIONAL
+         */
+        enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+
+        /*
          * suspend support
          */
         int (*resume)(struct scsi_device *);