bdev: add accessor function to get an I/O's iovec

Change-Id: I09321abe93303d6225fbcce4065b0024dd541b19
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/bdev.h

@@ -389,4 +389,13 @@ void spdk_bdev_io_get_nvme_status(const struct spdk_bdev_io *bdev_io, int *sct,
 void spdk_bdev_io_get_scsi_status(const struct spdk_bdev_io *bdev_io,
 				  int *sc, int *sk, int *asc, int *ascq);
 
+/**
+ * Get the iovec describing the data buffer of a bdev_io.
+ *
+ * \param bdev_io I/O to describe with iovec.
+ * \param iovp Pointer to be filled with iovec.
+ * \param iovcntp Pointer to be filled with number of iovec entries.
+ */
+void spdk_bdev_io_get_iovec(struct spdk_bdev_io *bdev_io, struct iovec **iovp, int *iovcntp);
+
 #endif /* SPDK_BDEV_H_ */

lib/bdev/bdev.c

@@ -1105,6 +1105,39 @@ spdk_bdev_io_get_rbuf(struct spdk_bdev_io *bdev_io, spdk_bdev_io_get_rbuf_cb cb)
 	}
 }
 
+void
+spdk_bdev_io_get_iovec(struct spdk_bdev_io *bdev_io, struct iovec **iovp, int *iovcntp)
+{
+	struct iovec *iovs;
+	int iovcnt;
+
+	if (bdev_io == NULL) {
+		return;
+	}
+
+	switch (bdev_io->type) {
+	case SPDK_BDEV_IO_TYPE_READ:
+		iovs = bdev_io->u.read.iovs;
+		iovcnt = bdev_io->u.read.iovcnt;
+		break;
+	case SPDK_BDEV_IO_TYPE_WRITE:
+		iovs = bdev_io->u.write.iovs;
+		iovcnt = bdev_io->u.write.iovcnt;
+		break;
+	default:
+		iovs = NULL;
+		iovcnt = 0;
+		break;
+	}
+
+	if (iovp) {
+		*iovp = iovs;
+	}
+	if (iovcntp) {
+		*iovcntp = iovcnt;
+	}
+}
+
 void spdk_bdev_module_list_add(struct spdk_bdev_module_if *bdev_module)
 {
 	TAILQ_INSERT_TAIL(&spdk_bdev_module_list, bdev_module, tailq);

lib/scsi/scsi_bdev.c

@@ -1225,6 +1225,8 @@ spdk_bdev_scsi_task_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_sta
 			     void *cb_arg)
 {
 	struct spdk_scsi_task		*task = cb_arg;
+	struct iovec			*iovs;
+	int				iovcnt;
 
 	if (task->type == SPDK_SCSI_TASK_TYPE_CMD) {
 		int sc, sk, asc, ascq;
@@ -1235,9 +1237,12 @@ spdk_bdev_scsi_task_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_sta
 		if (status == SPDK_BDEV_IO_STATUS_SUCCESS)
 			task->response = SPDK_SCSI_TASK_MGMT_RESP_SUCCESS;
 	}
-	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ && task->iovs != bdev_io->u.read.iovs) {
-		assert(task->iovcnt == bdev_io->u.read.iovcnt);
-		memcpy(task->iovs, bdev_io->u.read.iovs, sizeof(task->iovs[0]) * task->iovcnt);
+
+	spdk_bdev_io_get_iovec(bdev_io, &iovs, &iovcnt);
+	if (task->dxfer_dir == SPDK_SCSI_DIR_FROM_DEV && task->iovs != iovs) {
+		assert(iovs != NULL);
+		assert(task->iovcnt == iovcnt);
+		memcpy(task->iovs, iovs, sizeof(task->iovs[0]) * task->iovcnt);
 	}
 
 	spdk_scsi_lun_complete_task(task->lun, task);

test/lib/bdev/bdevperf/bdevperf.c

@@ -191,6 +191,8 @@ bdevperf_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status status,
 	struct io_target	*target;
 	struct bdevperf_task	*task = cb_arg;
 	struct spdk_event 	*complete;
+	struct iovec		*iovs;
+	int			iovcnt;
 
 	target = task->target;
 
@@ -200,8 +202,10 @@ bdevperf_complete(struct spdk_bdev_io *bdev_io, enum spdk_bdev_io_status status,
 			g_run_failed = true;
 		}
 	} else if (g_verify || g_reset || g_unmap) {
-		assert(bdev_io->u.read.iovcnt == 1);
-		if (memcmp(task->buf, bdev_io->u.read.iov.iov_base, g_io_size) != 0) {
+		spdk_bdev_io_get_iovec(bdev_io, &iovs, &iovcnt);
+		assert(iovcnt == 1);
+		assert(iovs != NULL);
+		if (memcmp(task->buf, iovs[0].iov_base, g_io_size) != 0) {
 			printf("Buffer mismatch! Disk Offset: %lu\n", task->offset);
 			target->is_draining = true;
 			g_run_failed = true;

test/lib/scsi/scsi_bdev/scsi_bdev_ut.c

@@ -133,6 +133,13 @@ spdk_bdev_io_get_scsi_status(const struct spdk_bdev_io *bdev_io,
 	}
 }
 
+void
+spdk_bdev_io_get_iovec(struct spdk_bdev_io *bdev_io, struct iovec **iovp, int *iovcntp)
+{
+	*iovp = NULL;
+	*iovcntp = 0;
+}
+
 struct spdk_bdev_io *
 spdk_bdev_read(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 	       void *buf, uint64_t offset, uint64_t nbytes,