[SCSI] fix sym scsi boot hang (59897dad) · Commits · 戴 / test

On Wed, 2005-09-14 at 18:06 +1000, Anton Blanchard wrote: > And in particular it looks like the scsi_unprep_request in > scsi_queue_insert is causing it. The following patch fixes the boot > problems on the vscsi machine: OK, my fault. Your fix is almost correct .. I was going to do this eventually, honest, because there's no need to unprep and reprep a command that comes in through scsi_queue_insert(). However, I decided to leave it in to exercise the scsi_unprep_request() path just to make sure it was working. What's happening, I think, is that we also use this path for retries. Since we kill and reget the command each time, the retries decrement is never seen, so we're retrying forever. Signed-off-by:

James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_lib.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -140,14 +140,12 @@ static void scsi_unprep_request(struct request *req)
		* commands.
		* Notes: This could be called either from an interrupt context or a
		* normal process context.
		* Notes: Upon return, cmd is a stale pointer.
		*/
		int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
		{
		struct Scsi_Host *host = cmd->device->host;
		struct scsi_device *device = cmd->device;
		struct request_queue *q = device->request_queue;
		struct request *req = cmd->request;
		unsigned long flags;

		SCSI_LOG_MLQUEUE(1,
		@@ -188,9 +186,8 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
		* function. The SCSI request function detects the blocked condition
		* and plugs the queue appropriately.
		*/
		scsi_unprep_request(req);
		spin_lock_irqsave(q->queue_lock, flags);
		blk_requeue_request(q, req);
		blk_requeue_request(q, cmd->request);
		spin_unlock_irqrestore(q->queue_lock, flags);

		scsi_run_queue(q);

Admin message