skd: Reorder the code in skd_process_request()

Prepare the S/G-list before allocating a FIT msg such that the FIT
msg always contains at least one request after the for-loop is
finished.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index ab344bfa91c9d24775727843c8e0046590e3a675..cbebaf4b08781ba5e610f390ea1ca006e0940c04 100644 (file)
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -612,6 +612,15 @@ static void skd_request_fn(struct request_queue *q)
                skreq->req = req;
                skreq->fitmsg_id = 0;
 
+               skreq->sg_data_dir = data_dir == READ ?
+                       SKD_DATA_DIR_CARD_TO_HOST : SKD_DATA_DIR_HOST_TO_CARD;
+
+               if (req->bio && !skd_preop_sg_list(skdev, skreq)) {
+                       dev_dbg(&skdev->pdev->dev, "error Out\n");
+                       skd_end_request(skdev, skreq, BLK_STS_RESOURCE);
+                       continue;
+               }
+
                /* Either a FIT msg is in progress or we have to start one. */
                if (skmsg == NULL) {
                        /* Are there any FIT msg buffers available? */
@@ -639,15 +648,6 @@ static void skd_request_fn(struct request_queue *q)
 
                skreq->fitmsg_id = skmsg->id;
 
-               /*
-                * Note that a FIT msg may have just been started
-                * but contains no SoFIT requests yet.
-                */
-
-               /*
-                * Transcode the request, checking as we go. The outcome of
-                * the transcoding is represented by the error variable.
-                */
                cmd_ptr = &skmsg->msg_buf[skmsg->length];
                memset(cmd_ptr, 0, 32);
 
@@ -658,11 +658,6 @@ static void skd_request_fn(struct request_queue *q)
                scsi_req->hdr.tag = cmdctxt;
                scsi_req->hdr.sg_list_dma_address = be_dmaa;
 
-               if (data_dir == READ)
-                       skreq->sg_data_dir = SKD_DATA_DIR_CARD_TO_HOST;
-               else
-                       skreq->sg_data_dir = SKD_DATA_DIR_HOST_TO_CARD;
-
                if (flush == SKD_FLUSH_ZERO_SIZE_FIRST) {
                        skd_prep_zerosize_flush_cdb(scsi_req, skreq);
                        SKD_ASSERT(skreq->flush_cmd == 1);
@@ -673,25 +668,6 @@ static void skd_request_fn(struct request_queue *q)
                if (fua)
                        scsi_req->cdb[1] |= SKD_FUA_NV;
 
-               if (!req->bio)
-                       goto skip_sg;
-
-               if (!skd_preop_sg_list(skdev, skreq)) {
-                       /*
-                        * Complete the native request with error.
-                        * Note that the request context is still at the
-                        * head of the free list, and that the SoFIT request
-                        * was encoded into the FIT msg buffer but the FIT
-                        * msg length has not been updated. In short, the
-                        * only resource that has been allocated but might
-                        * not be used is that the FIT msg could be empty.
-                        */
-                       dev_dbg(&skdev->pdev->dev, "error Out\n");
-                       skd_end_request(skdev, skreq, BLK_STS_RESOURCE);
-                       continue;
-               }
-
-skip_sg:
                scsi_req->hdr.sg_list_len_bytes =
                        cpu_to_be32(skreq->sg_byte_count);