Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

[tomoyo/tomoyo-test1.git] / drivers / scsi / scsi_lib.c

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 06c260f..df4905d 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -978,28 +978,12 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                scsi_io_completion_action(cmd, result);
 }
 
-static blk_status_t scsi_init_sgtable(struct request *req,
-               struct scsi_data_buffer *sdb)
+static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
+               struct request *rq)
 {
-       int count;
-
-       /*
-        * If sg table allocation fails, requeue request later.
-        */
-       if (unlikely(sg_alloc_table_chained(&sdb->table,
-                       blk_rq_nr_phys_segments(req), sdb->table.sgl,
-                       SCSI_INLINE_SG_CNT)))
-               return BLK_STS_RESOURCE;
-
-       /* 
-        * Next, walk the list, and fill in the addresses and sizes of
-        * each segment.
-        */
-       count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
-       BUG_ON(count > sdb->table.nents);
-       sdb->table.nents = count;
-       sdb->length = blk_rq_payload_bytes(req);
-       return BLK_STS_OK;
+       return sdev->dma_drain_len && blk_rq_is_passthrough(rq) &&
+              !op_is_write(req_op(rq)) &&
+              sdev->host->hostt->dma_need_drain(rq);
 }
 
 /*
@@ -1015,19 +999,62 @@ static blk_status_t scsi_init_sgtable(struct request *req,
  */
 blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
 {
+       struct scsi_device *sdev = cmd->device;
        struct request *rq = cmd->request;
+       unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
+       struct scatterlist *last_sg = NULL;
        blk_status_t ret;
+       bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq);
+       int count;
 
-       if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
+       if (WARN_ON_ONCE(!nr_segs))
                return BLK_STS_IOERR;
 
-       ret = scsi_init_sgtable(rq, &cmd->sdb);
-       if (ret)
-               return ret;
+       /*
+        * Make sure there is space for the drain.  The driver must adjust
+        * max_hw_segments to be prepared for this.
+        */
+       if (need_drain)
+               nr_segs++;
+
+       /*
+        * If sg table allocation fails, requeue request later.
+        */
+       if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs,
+                       cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT)))
+               return BLK_STS_RESOURCE;
+
+       /*
+        * Next, walk the list, and fill in the addresses and sizes of
+        * each segment.
+        */
+       count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg);
+
+       if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) {
+               unsigned int pad_len =
+                       (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
+
+               last_sg->length += pad_len;
+               cmd->extra_len += pad_len;
+       }
+
+       if (need_drain) {
+               sg_unmark_end(last_sg);
+               last_sg = sg_next(last_sg);
+               sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len);
+               sg_mark_end(last_sg);
+
+               cmd->extra_len += sdev->dma_drain_len;
+               count++;
+       }
+
+       BUG_ON(count > cmd->sdb.table.nents);
+       cmd->sdb.table.nents = count;
+       cmd->sdb.length = blk_rq_payload_bytes(rq);
 
        if (blk_integrity_rq(rq)) {
                struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
-               int ivecs, count;
+               int ivecs;
 
                if (WARN_ON_ONCE(!prot_sdb)) {
                        /*
@@ -1610,12 +1637,7 @@ static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
        struct request_queue *q = hctx->queue;
        struct scsi_device *sdev = q->queuedata;
 
-       if (scsi_dev_queue_ready(q, sdev))
-               return true;
-
-       if (atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev))
-               blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
-       return false;
+       return scsi_dev_queue_ready(q, sdev);
 }
 
 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
@@ -1684,6 +1706,7 @@ out_put_budget:
        case BLK_STS_OK:
                break;
        case BLK_STS_RESOURCE:
+       case BLK_STS_ZONE_RESOURCE:
                if (atomic_read(&sdev->device_busy) ||
                    scsi_device_blocked(sdev))
                        ret = BLK_STS_DEV_RESOURCE;