scsi: sd: Do not issue commands to suspended disks on shutdown

If an error occurs when resuming a host adapter before the devices
attached to the adapter are resumed, the adapter low level driver may
remove the scsi host, resulting in a call to sd_remove() for the
disks of the host. This in turn results in a call to sd_shutdown() which
will issue a synchronize cache command and a start stop unit command to
spindown the disk. sd_shutdown() issues the commands only if the device
is not already runtime suspended but does not check the power state for
system-wide suspend/resume. That is, the commands may be issued with the
device in a suspended state, which causes PM resume to hang, forcing a
reset of the machine to recover.

Fix this by tracking the suspended state of a disk by introducing the
suspended boolean field in the scsi_disk structure. This flag is set to
true when the disk is suspended is sd_suspend_common() and resumed with
sd_resume(). When suspended is true, sd_shutdown() is not executed from
sd_remove().

Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 5a1b802..83b6a3f 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3741,7 +3741,8 @@ static int sd_remove(struct device *dev)
 
        device_del(&sdkp->disk_dev);
        del_gendisk(sdkp->disk);
-       sd_shutdown(dev);
+       if (!sdkp->suspended)
+               sd_shutdown(dev);
 
        put_disk(sdkp->disk);
        return 0;
@@ -3872,6 +3873,9 @@ static int sd_suspend_common(struct device *dev, bool runtime)
                        ret = 0;
        }
 
+       if (!ret)
+               sdkp->suspended = true;
+
        return ret;
 }
 
@@ -3891,21 +3895,26 @@ static int sd_suspend_runtime(struct device *dev)
 static int sd_resume(struct device *dev, bool runtime)
 {
        struct scsi_disk *sdkp = dev_get_drvdata(dev);
-       int ret;
+       int ret = 0;
 
        if (!sdkp)      /* E.g.: runtime resume at the start of sd_probe() */
                return 0;
 
-       if (!sd_do_start_stop(sdkp->device, runtime))
+       if (!sd_do_start_stop(sdkp->device, runtime)) {
+               sdkp->suspended = false;
                return 0;
+       }
 
        if (!sdkp->device->no_start_on_resume) {
                sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
                ret = sd_start_stop_device(sdkp, 1);
        }
 
-       if (!ret)
+       if (!ret) {
                opal_unlock_from_suspend(sdkp->opal_dev);
+               sdkp->suspended = false;
+       }
+
        return ret;
 }
 

diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 5eea762..409dda5 100644 (file)
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -131,6 +131,7 @@ struct scsi_disk {
        u8              provisioning_mode;
        u8              zeroing_mode;
        u8              nr_actuators;           /* Number of actuators */
+       bool            suspended;      /* Disk is suspended (stopped) */
        unsigned        ATO : 1;        /* state of disk ATO bit */
        unsigned        cache_override : 1; /* temp override of WCE,RCD */
        unsigned        WCE : 1;        /* state of disk WCE bit */