scsi: restructure command initialization for TYPE_FS requests

We should call the device handler prep_fn for all TYPE_FS requests,
not just simple read/write calls that are handled by the disk driver.

Restructure the common I/O code to call the prep_fn handler and zero
out the CDB, and just leave the call to scsi_init_io to the ULDs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

1 files changed, 12 insertions, 10 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 150d7bb675a1..2afb96b801cb 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1082,11 +1082,10 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
 
 /*
- * Setup a REQ_TYPE_FS command.  These are simple read/write request
- * from filesystems that still need to be translated to SCSI CDBs from
- * the ULD.
+ * Setup a REQ_TYPE_FS command.  These are simple request from filesystems
+ * that still need to be translated to SCSI CDBs from the ULD.
  */
-int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
+static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
 {
         struct scsi_cmnd *cmd = req->special;
 
@@ -1098,9 +1097,8 @@ int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
         }
 
         memset(cmd->cmnd, 0, BLK_MAX_CDB);
-        return scsi_init_io(cmd, GFP_ATOMIC);
+        return scsi_cmd_to_driver(cmd)->init_command(cmd);
 }
-EXPORT_SYMBOL(scsi_setup_fs_cmnd);
 
 static int
 scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
@@ -1205,12 +1203,16 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                 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)
+        switch (req->cmd_type) {
+        case REQ_TYPE_FS:
+                ret = scsi_setup_fs_cmnd(sdev, req);
+                break;
+        case REQ_TYPE_BLOCK_PC:
                 ret = scsi_setup_blk_pc_cmnd(sdev, req);
-        else
+                break;
+        default:
                 ret = BLKPREP_KILL;
+        }
 
 out:
         return scsi_prep_return(q, req, ret);