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-rw-r--r--drivers/scsi/scsi_scan.c18
-rw-r--r--include/scsi/scsi_host.h2
2 files changed, 18 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 52014b2d39e1..3db4d31a03a1 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1619,12 +1619,24 @@ int scsi_add_device(struct Scsi_Host *host, uint channel,
}
EXPORT_SYMBOL(scsi_add_device);
-void scsi_rescan_device(struct scsi_device *sdev)
+int scsi_rescan_device(struct scsi_device *sdev)
{
struct device *dev = &sdev->sdev_gendev;
+ int ret = 0;
device_lock(dev);
+ /*
+ * Bail out if the device is not running. Otherwise, the rescan may
+ * block waiting for commands to be executed, with us holding the
+ * device lock. This can result in a potential deadlock in the power
+ * management core code when system resume is on-going.
+ */
+ if (sdev->sdev_state != SDEV_RUNNING) {
+ ret = -EWOULDBLOCK;
+ goto unlock;
+ }
+
scsi_attach_vpd(sdev);
scsi_cdl_check(sdev);
@@ -1638,7 +1650,11 @@ void scsi_rescan_device(struct scsi_device *sdev)
drv->rescan(dev);
module_put(dev->driver->owner);
}
+
+unlock:
device_unlock(dev);
+
+ return ret;
}
EXPORT_SYMBOL(scsi_rescan_device);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 49f768d0ff37..4c2dc8150c6d 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -764,7 +764,7 @@ scsi_template_proc_dir(const struct scsi_host_template *sht);
#define scsi_template_proc_dir(sht) NULL
#endif
extern void scsi_scan_host(struct Scsi_Host *);
-extern void scsi_rescan_device(struct scsi_device *);
+extern int scsi_rescan_device(struct scsi_device *sdev);
extern void scsi_remove_host(struct Scsi_Host *);
extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
extern int scsi_host_busy(struct Scsi_Host *shost);