[SCSI] sd: implement START/STOP management
Implement SBC START/STOP management. sdev->mange_start_stop is added.
When it's set to one, sd STOPs the device on suspend and shutdown and
STARTs it on resume. sdev->manage_start_stop defaults is in sdev
instead of scsi_disk cdev to allow ->slave_config() override the
default configuration but is exported under scsi_disk sysfs node as
sdev->allow_restart is.
When manage_start_stop is zero (the default value), this patch doesn't
introduce any behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Rejections fixed and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3dda77c..49a94ae 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -147,6 +147,20 @@
return count;
}
+static ssize_t sd_store_manage_start_stop(struct class_device *cdev,
+ const char *buf, size_t count)
+{
+ struct scsi_disk *sdkp = to_scsi_disk(cdev);
+ struct scsi_device *sdp = sdkp->device;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
+
+ return count;
+}
+
static ssize_t sd_store_allow_restart(struct class_device *cdev, const char *buf,
size_t count)
{
@@ -179,6 +193,14 @@
return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
}
+static ssize_t sd_show_manage_start_stop(struct class_device *cdev, char *buf)
+{
+ struct scsi_disk *sdkp = to_scsi_disk(cdev);
+ struct scsi_device *sdp = sdkp->device;
+
+ return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
+}
+
static ssize_t sd_show_allow_restart(struct class_device *cdev, char *buf)
{
struct scsi_disk *sdkp = to_scsi_disk(cdev);
@@ -192,6 +214,8 @@
__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
sd_store_allow_restart),
+ __ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
+ sd_store_manage_start_stop),
__ATTR_NULL,
};
@@ -208,6 +232,8 @@
.name = "sd",
.probe = sd_probe,
.remove = sd_remove,
+ .suspend = sd_suspend,
+ .resume = sd_resume,
.shutdown = sd_shutdown,
},
.rescan = sd_rescan,
@@ -1707,6 +1733,32 @@
kfree(sdkp);
}
+static int sd_start_stop_device(struct scsi_device *sdp, int start)
+{
+ unsigned char cmd[6] = { START_STOP }; /* START_VALID */
+ struct scsi_sense_hdr sshdr;
+ int res;
+
+ if (start)
+ cmd[4] |= 1; /* START */
+
+ if (!scsi_device_online(sdp))
+ return -ENODEV;
+
+ res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
+ SD_TIMEOUT, SD_MAX_RETRIES);
+ if (res) {
+ printk(KERN_WARNING "FAILED\n status = %x, message = %02x, "
+ "host = %d, driver = %02x\n ",
+ status_byte(res), msg_byte(res),
+ host_byte(res), driver_byte(res));
+ if (driver_byte(res) & DRIVER_SENSE)
+ scsi_print_sense_hdr("sd", &sshdr);
+ }
+
+ return res;
+}
+
/*
* Send a SYNCHRONIZE CACHE instruction down to the device through
* the normal SCSI command structure. Wait for the command to
@@ -1714,6 +1766,7 @@
*/
static void sd_shutdown(struct device *dev)
{
+ struct scsi_device *sdp = to_scsi_device(dev);
struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
if (!sdkp)
@@ -1723,9 +1776,57 @@
sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
sd_sync_cache(sdkp);
}
+
+ if (system_state != SYSTEM_RESTART && sdp->manage_start_stop) {
+ printk(KERN_NOTICE "Stopping disk %s: \n",
+ sdkp->disk->disk_name);
+ sd_start_stop_device(sdp, 0);
+ }
+
scsi_disk_put(sdkp);
}
+static int sd_suspend(struct device *dev, pm_message_t mesg)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
+ int ret;
+
+ if (!sdkp)
+ return 0; /* this can happen */
+
+ if (sdkp->WCE) {
+ printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
+ sdkp->disk->disk_name);
+ ret = sd_sync_cache(sdkp);
+ if (ret)
+ return ret;
+ }
+
+ if (mesg.event == PM_EVENT_SUSPEND && sdp->manage_start_stop) {
+ printk(KERN_NOTICE "Stopping disk %s: \n",
+ sdkp->disk->disk_name);
+ ret = sd_start_stop_device(sdp, 0);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int sd_resume(struct device *dev)
+{
+ struct scsi_device *sdp = to_scsi_device(dev);
+ struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
+
+ if (!sdp->manage_start_stop)
+ return 0;
+
+ printk(KERN_NOTICE "Starting disk %s: \n", sdkp->disk->disk_name);
+
+ return sd_start_stop_device(sdp, 1);
+}
+
/**
* init_sd - entry point for this driver (both when built in or when
* a module).