[PATCH 12/17] hw/block/nvme: refactor NvmeRequest clearing

[Klaus Jensen]

From: Klaus Jensen <k.jensen@samsung.com>

Move clearing of the structure from "clear before use" to "clear after
use". Also, carry a reference to the namespace the (I/O) command is
acting on instead of passing it around explicitly.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/block/nvme.c | 28 ++++++++++++++++------------
 hw/block/nvme.h |  1 +
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 12f1b6331c43..3d38f61b61e5 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -174,6 +174,12 @@ static void nvme_irq_deassert(NvmeCtrl *n, NvmeCQueue *cq)
     }
 }
 
+static void nvme_req_clear(NvmeRequest *req)
+{
+    req->ns = NULL;
+    memset(&req->cqe, 0x0, sizeof(req->cqe));
+}
+
 static uint16_t nvme_map_addr_cmb(NvmeCtrl *n, QEMUIOVector *iov, hwaddr addr,
                                   size_t len)
 {
@@ -423,6 +429,7 @@ static void nvme_post_cqes(void *opaque)
         nvme_inc_cq_tail(cq);
         pci_dma_write(&n->parent_obj, addr, (void *)&req->cqe,
             sizeof(req->cqe));
+        nvme_req_clear(req);
         QTAILQ_INSERT_TAIL(&sq->req_list, req, entry);
     }
     if (cq->tail != cq->head) {
@@ -569,8 +576,7 @@ static void nvme_rw_cb(void *opaque, int ret)
     nvme_enqueue_req_completion(cq, req);
 }
 
-static uint16_t nvme_flush(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
-    NvmeRequest *req)
+static uint16_t nvme_flush(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
     block_acct_start(blk_get_stats(n->conf.blk), &req->acct, 0,
          BLOCK_ACCT_FLUSH);
@@ -579,10 +585,10 @@ static uint16_t nvme_flush(NvmeCtrl *n, NvmeNamespace 
*ns, NvmeCmd *cmd,
     return NVME_NO_COMPLETE;
 }
 
-static uint16_t nvme_write_zeroes(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
-    NvmeRequest *req)
+static uint16_t nvme_write_zeroes(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
     NvmeRwCmd *rw = (NvmeRwCmd *)cmd;
+    NvmeNamespace *ns = req->ns;
     const uint8_t lba_index = NVME_ID_NS_FLBAS_INDEX(ns->id_ns.flbas);
     const uint8_t data_shift = ns->id_ns.lbaf[lba_index].ds;
     uint64_t slba = le64_to_cpu(rw->slba);
@@ -606,10 +612,10 @@ static uint16_t nvme_write_zeroes(NvmeCtrl *n, 
NvmeNamespace *ns, NvmeCmd *cmd,
     return NVME_NO_COMPLETE;
 }
 
-static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
-    NvmeRequest *req)
+static uint16_t nvme_rw(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
     NvmeRwCmd *rw = (NvmeRwCmd *)cmd;
+    NvmeNamespace *ns = req->ns;
     uint32_t nlb  = le32_to_cpu(rw->nlb) + 1;
     uint64_t slba = le64_to_cpu(rw->slba);
 
@@ -665,7 +671,6 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, 
NvmeCmd *cmd,
 
 static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
-    NvmeNamespace *ns;
     uint32_t nsid = le32_to_cpu(cmd->nsid);
 
     trace_pci_nvme_io_cmd(nvme_cid(req), nsid, nvme_sqid(req), cmd->opcode);
@@ -675,15 +680,15 @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, 
NvmeRequest *req)
         return NVME_INVALID_NSID | NVME_DNR;
     }
 
-    ns = &n->namespaces[nsid - 1];
+    req->ns = &n->namespaces[nsid - 1];
     switch (cmd->opcode) {
     case NVME_CMD_FLUSH:
-        return nvme_flush(n, ns, cmd, req);
+        return nvme_flush(n, cmd, req);
     case NVME_CMD_WRITE_ZEROES:
-        return nvme_write_zeroes(n, ns, cmd, req);
+        return nvme_write_zeroes(n, cmd, req);
     case NVME_CMD_WRITE:
     case NVME_CMD_READ:
-        return nvme_rw(n, ns, cmd, req);
+        return nvme_rw(n, cmd, req);
     default:
         trace_pci_nvme_err_invalid_opc(cmd->opcode);
         return NVME_INVALID_OPCODE | NVME_DNR;
@@ -1554,7 +1559,6 @@ static void nvme_process_sq(void *opaque)
         req = QTAILQ_FIRST(&sq->req_list);
         QTAILQ_REMOVE(&sq->req_list, req, entry);
         QTAILQ_INSERT_TAIL(&sq->out_req_list, req, entry);
-        memset(&req->cqe, 0, sizeof(req->cqe));
         req->cqe.cid = cmd.cid;
 
         status = sq->sqid ? nvme_io_cmd(n, &cmd, req) :
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index b5ce51c6e84b..6eaafd2e35f5 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -21,6 +21,7 @@ typedef struct NvmeAsyncEvent {
 
 typedef struct NvmeRequest {
     struct NvmeSQueue       *sq;
+    struct NvmeNamespace    *ns;
     BlockAIOCB              *aiocb;
     uint16_t                status;
     NvmeCqe                 cqe;
-- 
2.27.0