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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 6b78476..9e0c63e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -564,10 +564,12 @@
}
}
-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 @@
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 @@
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 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);
- }
+ revalidate_disk(sdkp->disk);
}
@@ -3149,13 +3125,13 @@
*/
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 @@
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 @@
}
done:
- scsi_disk_put(sdkp);
return ret;
}
@@ -3215,18 +3187,13 @@
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);
}
/**