scsi: reintroduce scsi_driver.init_command
Instead of letting the ULD play games with the prep_fn move back to
the model of a central prep_fn with a callback to the ULD. This
already cleans up and shortens the code by itself, and will be required
to properly support blk-mq in the SCSI midlayer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 045822b..9f841df 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1073,15 +1073,7 @@
int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
{
- struct scsi_cmnd *cmd;
- int ret = scsi_prep_state_check(sdev, req);
-
- if (ret != BLKPREP_OK)
- return ret;
-
- cmd = scsi_get_cmd_from_req(sdev, req);
- if (unlikely(!cmd))
- return BLKPREP_DEFER;
+ struct scsi_cmnd *cmd = req->special;
/*
* BLOCK_PC requests may transfer data, in which case they must
@@ -1125,15 +1117,11 @@
*/
int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
{
- struct scsi_cmnd *cmd;
- int ret = scsi_prep_state_check(sdev, req);
-
- if (ret != BLKPREP_OK)
- return ret;
+ struct scsi_cmnd *cmd = req->special;
if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh
&& sdev->scsi_dh_data->scsi_dh->prep_fn)) {
- ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
+ int ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
if (ret != BLKPREP_OK)
return ret;
}
@@ -1143,16 +1131,13 @@
*/
BUG_ON(!req->nr_phys_segments);
- cmd = scsi_get_cmd_from_req(sdev, req);
- if (unlikely(!cmd))
- return BLKPREP_DEFER;
-
memset(cmd->cmnd, 0, BLK_MAX_CDB);
return scsi_init_io(cmd, GFP_ATOMIC);
}
EXPORT_SYMBOL(scsi_setup_fs_cmnd);
-int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
+static int
+scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
{
int ret = BLKPREP_OK;
@@ -1204,9 +1189,9 @@
}
return ret;
}
-EXPORT_SYMBOL(scsi_prep_state_check);
-int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+static int
+scsi_prep_return(struct request_queue *q, struct request *req, int ret)
{
struct scsi_device *sdev = q->queuedata;
@@ -1237,18 +1222,44 @@
return ret;
}
-EXPORT_SYMBOL(scsi_prep_return);
-int scsi_prep_fn(struct request_queue *q, struct request *req)
+static int scsi_prep_fn(struct request_queue *q, struct request *req)
{
struct scsi_device *sdev = q->queuedata;
- int ret = BLKPREP_KILL;
+ struct scsi_cmnd *cmd;
+ int ret;
- if (req->cmd_type == REQ_TYPE_BLOCK_PC)
+ ret = scsi_prep_state_check(sdev, req);
+ if (ret != BLKPREP_OK)
+ goto out;
+
+ cmd = scsi_get_cmd_from_req(sdev, req);
+ if (unlikely(!cmd)) {
+ ret = BLKPREP_DEFER;
+ goto out;
+ }
+
+ if (req->cmd_type == REQ_TYPE_FS)
+ ret = scsi_cmd_to_driver(cmd)->init_command(cmd);
+ else if (req->cmd_type == REQ_TYPE_BLOCK_PC)
ret = scsi_setup_blk_pc_cmnd(sdev, req);
+ else
+ ret = BLKPREP_KILL;
+
+out:
return scsi_prep_return(q, req, ret);
}
-EXPORT_SYMBOL(scsi_prep_fn);
+
+static void scsi_unprep_fn(struct request_queue *q, struct request *req)
+{
+ if (req->cmd_type == REQ_TYPE_FS) {
+ struct scsi_cmnd *cmd = req->special;
+ struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
+
+ if (drv->uninit_command)
+ drv->uninit_command(cmd);
+ }
+}
/*
* scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
@@ -1669,6 +1680,7 @@
return NULL;
blk_queue_prep_rq(q, scsi_prep_fn);
+ blk_queue_unprep_rq(q, scsi_unprep_fn);
blk_queue_softirq_done(q, scsi_softirq_done);
blk_queue_rq_timed_out(q, scsi_times_out);
blk_queue_lld_busy(q, scsi_lld_busy);