Revert revert of "[SCSI] fix usb storage oops"
This reverts commit 1b0997f561bf46689cc6e0903f342e9bf2506bf1, which in
turn reverted 34ea80ec6a02ad02e6b9c75c478c18e5880d6713 (which is thus
re-instated).
Quoth James Bottomley:
"All it's doing is deferring the device_put() from the
scsi_put_command() to after the scsi_run_queue(), which doesn't fix
the sleep while atomic problem of the device release method. In both
cases we still get the semaphore in atomic context problem which is
caused by scsi_reap_target() doing a device_del(), which I assumed
(wrongly) was valid from atomic context."
who also promised to fix scsi_reap_target().
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 4afef5c..ce9d73a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -542,10 +542,17 @@
void scsi_next_command(struct scsi_cmnd *cmd)
{
- struct request_queue *q = cmd->device->request_queue;
+ struct scsi_device *sdev = cmd->device;
+ struct request_queue *q = sdev->request_queue;
+
+ /* need to hold a reference on the device before we let go of the cmd */
+ get_device(&sdev->sdev_gendev);
scsi_put_command(cmd);
scsi_run_queue(q);
+
+ /* ok to remove device now */
+ put_device(&sdev->sdev_gendev);
}
void scsi_run_host_queues(struct Scsi_Host *shost)
