James: When a request is deferred in scsi_init_io because the sg table could not be allocated, the associated scsi_cmnd is not released and the request is not marked with REQ_DONTPREP. When the command is retried, if scsi_prep_fn decides to kill it then the scsi_cmnd will never be released. This patch (as573) changes scsi_init_io so that it calls scsi_put_command before deferring a request. Alan Stern Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> --- It may still be too soon to apply this patch. I don't know how it will interact with the old scsi_request mechanism (if that is still being used). Also, at some stage you will want to delete the code paths in scsi_prep_fn that assign cmd = req->special, because unprepared requests will _never_ have an already-associated scsi_cmnd. Index: usb-2.6/drivers/scsi/scsi_lib.c =================================================================== --- usb-2.6.orig/drivers/scsi/scsi_lib.c +++ usb-2.6/drivers/scsi/scsi_lib.c @@ -97,7 +97,6 @@ int scsi_insert_special_req(struct scsi_ } static void scsi_run_queue(struct request_queue *q); -static void scsi_release_buffers(struct scsi_cmnd *cmd); /* * Function: scsi_unprep_request() @@ -1040,8 +1039,10 @@ static int scsi_init_io(struct scsi_cmnd * if sg table allocation fails, requeue request later. */ sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC); - if (unlikely(!sgpnt)) + if (unlikely(!sgpnt)) { + scsi_unprep_request(req); return BLKPREP_DEFER; + } cmd->request_buffer = (char *) sgpnt; cmd->request_bufflen = req->nr_sectors << 9; @@ -1245,8 +1246,8 @@ static int scsi_prep_fn(struct request_q */ ret = scsi_init_io(cmd); switch(ret) { + /* For BLKPREP_KILL/DEFER the cmd was released */ case BLKPREP_KILL: - /* BLKPREP_KILL return also releases the command */ goto kill; case BLKPREP_DEFER: goto defer; - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html