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Commit c3c94c5a authored by Tejun Heo's avatar Tejun Heo Committed by James Bottomley
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[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: default avatarTejun Heo <htejun@gmail.com>

Rejections fixed and
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 3721050a

drivers/scsi/scsi_sysfs.c

+27 −4
Original line number Diff line number Diff line
@@ -278,6 +278,7 @@ static int scsi_bus_match(struct device *dev, struct device_driver *gendrv) 


static int scsi_bus_suspend(struct device * dev, pm_message_t state)

{

	struct device_driver *drv = dev->driver;

	struct scsi_device *sdev = to_scsi_device(dev);

	struct scsi_host_template *sht = sdev->host->hostt;

	int err;
@@ -286,23 +287,45 @@ static int scsi_bus_suspend(struct device * dev, pm_message_t state) 
	if (err)

		return err;



	if (sht->suspend)

		err = sht->suspend(sdev, state);

	/* call HLD suspend first */

	if (drv && drv->suspend) {

		err = drv->suspend(dev, state);

		if (err)

			return err;

	}



	/* then, call host suspend */

	if (sht->suspend) {

		err = sht->suspend(sdev, state);

		if (err) {

			if (drv && drv->resume)

				drv->resume(dev);

			return err;

		}

	}



	return 0;

}



static int scsi_bus_resume(struct device * dev)

{

	struct device_driver *drv = dev->driver;

	struct scsi_device *sdev = to_scsi_device(dev);

	struct scsi_host_template *sht = sdev->host->hostt;

	int err = 0;

	int err = 0, err2 = 0;



	/* call host resume first */

	if (sht->resume)

		err = sht->resume(sdev);



	/* then, call HLD resume */

	if (drv && drv->resume)

		err2 = drv->resume(dev);



	scsi_device_resume(sdev);

	return err;



	/* favor LLD failure */

	return err ? err : err2;;

}



struct bus_type scsi_bus_type = {

drivers/scsi/sd.c

+101 −0
Original line number Diff line number Diff line
@@ -147,6 +147,20 @@ static ssize_t sd_store_cache_type(struct class_device *cdev, const char *buf, 
	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 @@ static ssize_t sd_show_fua(struct class_device *cdev, char *buf) 
	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 @@ static struct class_device_attribute sd_disk_attrs[] = { 
	__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 @@ static struct scsi_driver sd_template = { 
		.name		= "sd",

		.probe		= sd_probe,

		.remove		= sd_remove,

		.suspend	= sd_suspend,

		.resume		= sd_resume,

		.shutdown	= sd_shutdown,

	},

	.rescan			= sd_rescan,
@@ -1707,6 +1733,32 @@ static void scsi_disk_release(struct class_device *cdev) 
	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 scsi_disk_release(struct class_device *cdev) 
 */

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 @@ static void sd_shutdown(struct device *dev) 
		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).

include/scsi/scsi_device.h

+1 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ struct scsi_device { 
	unsigned use_192_bytes_for_3f:1; /* ask for 192 bytes from page 0x3f */

	unsigned no_start_on_add:1;	/* do not issue start on add */

	unsigned allow_restart:1; /* issue START_UNIT in error handler */

	unsigned manage_start_stop:1;	/* Let HLD (sd) manage start/stop */

	unsigned no_uld_attach:1; /* disable connecting to upper level drivers */

	unsigned select_no_atn:1;

	unsigned fix_capacity:1;	/* READ_CAPACITY is too high by 1 */

include/scsi/sd.h

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,8 @@ static void sd_rw_intr(struct scsi_cmnd * SCpnt); 
static int  sd_probe(struct device *);

static int  sd_remove(struct device *);

static void sd_shutdown(struct device *dev);

static int sd_suspend(struct device *dev, pm_message_t state);

static int sd_resume(struct device *dev);

static void sd_rescan(struct device *);

static int  sd_init_command(struct scsi_cmnd *);

static int  sd_issue_flush(struct device *, sector_t *);