block: unify request timeout handling

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 38 insertions, 22 deletions

diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index 822d5214692b..c387c15a2128 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -464,7 +464,6 @@ int __gdth_execute(struct scsi_device *sdev, gdth_cmd_str *gdtcmd, char *cmnd,
 
     /* use request field to save the ptr. to completion struct. */
     scp->request = (struct request *)&wait;
-    scp->timeout_per_command = timeout*HZ;
     scp->cmd_len = 12;
     scp->cmnd = cmnd;
     cmndinfo.priority = IOCTL_PRI;
@@ -1995,23 +1994,12 @@ static void gdth_putq(gdth_ha_str *ha, Scsi_Cmnd *scp, unchar priority)
     register Scsi_Cmnd *pscp;
     register Scsi_Cmnd *nscp;
     ulong flags;
-    unchar b, t;
 
     TRACE(("gdth_putq() priority %d\n",priority));
     spin_lock_irqsave(&ha->smp_lock, flags);
 
-    if (!cmndinfo->internal_command) {
+    if (!cmndinfo->internal_command)
         cmndinfo->priority = priority;
-        b = scp->device->channel;
-        t = scp->device->id;
-        if (priority >= DEFAULT_PRI) {
-            if ((b != ha->virt_bus && ha->raw[BUS_L2P(ha,b)].lock) ||
-                (b==ha->virt_bus && t<MAX_HDRIVES && ha->hdr[t].lock)) {
-                TRACE2(("gdth_putq(): locked IO ->update_timeout()\n"));
-                cmndinfo->timeout = gdth_update_timeout(scp, 0);
-            }
-        }
-    }
 
     if (ha->req_first==NULL) {
         ha->req_first = scp;                    /* queue was empty */
@@ -3899,6 +3887,39 @@ static const char *gdth_info(struct Scsi_Host *shp)
     return ((const char *)ha->binfo.type_string);
 }
 
+static enum blk_eh_timer_return gdth_timed_out(struct scsi_cmnd *scp)
+{
+        gdth_ha_str *ha = shost_priv(scp->device->host);
+        struct gdth_cmndinfo *cmndinfo = gdth_cmnd_priv(scp);
+        unchar b, t;
+        ulong flags;
+        enum blk_eh_timer_return retval = BLK_EH_NOT_HANDLED;
+
+        TRACE(("%s() cmd 0x%x\n", scp->cmnd[0], __func__));
+        b = scp->device->channel;
+        t = scp->device->id;
+
+        /*
+         * We don't really honor the command timeout, but we try to
+         * honor 6 times of the actual command timeout! So reset the
+         * timer if this is less than 6th timeout on this command!
+         */
+        if (++cmndinfo->timeout_count < 6)
+                retval = BLK_EH_RESET_TIMER;
+
+        /* Reset the timeout if it is locked IO */
+        spin_lock_irqsave(&ha->smp_lock, flags);
+        if ((b != ha->virt_bus && ha->raw[BUS_L2P(ha, b)].lock) ||
+            (b == ha->virt_bus && t < MAX_HDRIVES && ha->hdr[t].lock)) {
+                TRACE2(("%s(): locked IO, reset timeout\n", __func__));
+                retval = BLK_EH_RESET_TIMER;
+        }
+        spin_unlock_irqrestore(&ha->smp_lock, flags);
+
+        return retval;
+}
+
+
 static int gdth_eh_bus_reset(Scsi_Cmnd *scp)
 {
     gdth_ha_str *ha = shost_priv(scp->device->host);
@@ -3992,7 +4013,7 @@ static int gdth_queuecommand(struct scsi_cmnd *scp,
     BUG_ON(!cmndinfo);
 
     scp->scsi_done = done;
-    gdth_update_timeout(scp, scp->timeout_per_command * 6);
+    cmndinfo->timeout_count = 0;
     cmndinfo->priority = DEFAULT_PRI;
 
     return __gdth_queuecommand(ha, scp, cmndinfo);
@@ -4096,12 +4117,10 @@ static int ioc_lockdrv(void __user *arg)
             ha->hdr[j].lock = 1;
             spin_unlock_irqrestore(&ha->smp_lock, flags);
             gdth_wait_completion(ha, ha->bus_cnt, j);
-            gdth_stop_timeout(ha, ha->bus_cnt, j);
         } else {
             spin_lock_irqsave(&ha->smp_lock, flags);
             ha->hdr[j].lock = 0;
             spin_unlock_irqrestore(&ha->smp_lock, flags);
-            gdth_start_timeout(ha, ha->bus_cnt, j);
             gdth_next(ha);
         }
     } 
@@ -4539,18 +4558,14 @@ static int gdth_ioctl(struct inode *inode, struct file *filep,
                 spin_lock_irqsave(&ha->smp_lock, flags);
                 ha->raw[i].lock = 1;
                 spin_unlock_irqrestore(&ha->smp_lock, flags);
-                for (j = 0; j < ha->tid_cnt; ++j) {
+                for (j = 0; j < ha->tid_cnt; ++j)
                     gdth_wait_completion(ha, i, j);
-                    gdth_stop_timeout(ha, i, j);
-                }
             } else {
                 spin_lock_irqsave(&ha->smp_lock, flags);
                 ha->raw[i].lock = 0;
                 spin_unlock_irqrestore(&ha->smp_lock, flags);
-                for (j = 0; j < ha->tid_cnt; ++j) {
-                    gdth_start_timeout(ha, i, j);
+                for (j = 0; j < ha->tid_cnt; ++j)
                     gdth_next(ha);
-                }
             }
         } 
         break;
@@ -4644,6 +4659,7 @@ static struct scsi_host_template gdth_template = {
         .slave_configure        = gdth_slave_configure,
         .bios_param             = gdth_bios_param,
         .proc_info              = gdth_proc_info,
+        .eh_timed_out           = gdth_timed_out,
         .proc_name              = "gdth",
         .can_queue              = GDTH_MAXCMDS,
         .this_id                = -1,