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Commit 3d9a1f53 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by James Bottomley
Browse files

sd: don't grab a device references from driver methods 



The device model already takes care of races between ->remove and
->shutdown vs its other methods, and we now take care about locking
them out for ->rescan as well.

This is a partial revert of commit 39b7f1 ("[SCSI] sd: Fix refcounting").

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent e27829dc

drivers/scsi/sd.c

+11 −44
Original line number Diff line number Diff line
@@ -564,10 +564,12 @@ static int sd_major(int major_idx) 
	}

}



static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)

static struct scsi_disk *scsi_disk_get(struct gendisk *disk)

{

	struct scsi_disk *sdkp = NULL;



	mutex_lock(&sd_ref_mutex);



	if (disk->private_data) {

		sdkp = scsi_disk(disk);

		if (scsi_device_get(sdkp->device) == 0)
@@ -575,27 +577,6 @@ static struct scsi_disk *__scsi_disk_get(struct gendisk *disk) 
		else

			sdkp = NULL;

	}

	return sdkp;

}



static struct scsi_disk *scsi_disk_get(struct gendisk *disk)

{

	struct scsi_disk *sdkp;



	mutex_lock(&sd_ref_mutex);

	sdkp = __scsi_disk_get(disk);

	mutex_unlock(&sd_ref_mutex);

	return sdkp;

}



static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)

{

	struct scsi_disk *sdkp;



	mutex_lock(&sd_ref_mutex);

	sdkp = dev_get_drvdata(dev);

	if (sdkp)

		sdkp = __scsi_disk_get(sdkp->disk);

	mutex_unlock(&sd_ref_mutex);

	return sdkp;

}
@@ -610,8 +591,6 @@ static void scsi_disk_put(struct scsi_disk *sdkp) 
	mutex_unlock(&sd_ref_mutex);

}







static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd,

					   unsigned int dix, unsigned int dif)

{
@@ -1525,12 +1504,9 @@ static int sd_sync_cache(struct scsi_disk *sdkp) 


static void sd_rescan(struct device *dev)

{

	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);

	struct scsi_disk *sdkp = dev_get_drvdata(dev);



	if (sdkp) {

	revalidate_disk(sdkp->disk);

		scsi_disk_put(sdkp);

	}

}
@@ -3149,13 +3125,13 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start) 
 */

static void sd_shutdown(struct device *dev)

{

	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);

	struct scsi_disk *sdkp = dev_get_drvdata(dev);



	if (!sdkp)

		return;         /* this can happen */



	if (pm_runtime_suspended(dev))

		goto exit;

		return;



	if (sdkp->WCE && sdkp->media_present) {

		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
@@ -3166,14 +3142,11 @@ static void sd_shutdown(struct device *dev) 
		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");

		sd_start_stop_device(sdkp, 0);

	}



exit:

	scsi_disk_put(sdkp);

}



static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)

{

	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);

	struct scsi_disk *sdkp = dev_get_drvdata(dev);

	int ret = 0;



	if (!sdkp)
@@ -3199,7 +3172,6 @@ static int sd_suspend_common(struct device *dev, bool ignore_stop_errors) 
	}



done:

	scsi_disk_put(sdkp);

	return ret;

}
@@ -3215,18 +3187,13 @@ static int sd_suspend_runtime(struct device *dev) 


static int sd_resume(struct device *dev)

{

	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);

	int ret = 0;

	struct scsi_disk *sdkp = dev_get_drvdata(dev);



	if (!sdkp->device->manage_start_stop)

		goto done;

		return 0;



	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");

	ret = sd_start_stop_device(sdkp, 1);



done:

	scsi_disk_put(sdkp);

	return ret;

	return sd_start_stop_device(sdkp, 1);

}



/**