ptio: Improve ptio_open_dev()

Instead of always passing O_RDWR to ptio_open_dev(), pass the transfer
direction as the second argument and automatically decide on the open
mode based on that direction, that is, open the device read-write if
data is to be transfered to the device and read-only otherwise.

Signed-off-by: Damien Le Moal <[email protected]>

Author: damien-lemoal

src/ptio.c

@@ -59,7 +59,7 @@ static int ptio_revalidate(struct ptio_dev *dev)
 }
 
 static int ptio_exec(struct ptio_dev *dev, char *cdb_str,
-		     enum ptio_cdb_type cdb_type, int dxfer,
+		     enum ptio_cdb_type cdb_type, enum ptio_dxfer dxfer,
 		     char *buf_path, size_t bufsz)
 {
 	struct ptio_cmd cmd;
@@ -147,7 +147,7 @@ int main(int argc, char **argv)
 	struct ptio_dev dev;
 	char *cdb_str = NULL;
 	enum ptio_cdb_type cdb_type = PTIO_CDB_NONE;
-	int dxfer = PTIO_DXFER_NONE;
+	enum ptio_dxfer dxfer = PTIO_DXFER_NONE;
 	char *buf_path = NULL;
 	int bufsz = 0;
 	int i, ret;
@@ -277,7 +277,7 @@ int main(int argc, char **argv)
 	}
 
 	/* Open the device and printf some information about it */
-	ret = ptio_open_dev(&dev, O_RDWR);
+	ret = ptio_open_dev(&dev, dxfer);
 	if (ret)
 		return 1;
 

src/ptio.h

@@ -109,7 +109,7 @@ struct ptio_cmd {
 int ptio_get_sense(struct ptio_dev *dev, struct ptio_cmd *cmd);
 
 /* In ptio_dev.c */
-int ptio_open_dev(struct ptio_dev *dev, mode_t mode);
+int ptio_open_dev(struct ptio_dev *dev, enum ptio_dxfer dxfer);
 void ptio_close_dev(struct ptio_dev *dev);
 int ptio_revalidate_dev(struct ptio_dev *dev);
 int ptio_get_dev_information(struct ptio_dev *dev);

src/ptio_dev.c

@@ -548,9 +548,10 @@ int ptio_write_buf(char *path, uint8_t *buf, size_t bufsz)
 /*
  * Open a device.
  */
-int ptio_open_dev(struct ptio_dev *dev, mode_t mode)
+int ptio_open_dev(struct ptio_dev *dev, enum ptio_dxfer dxfer)
 {
 	struct stat st;
+	mode_t mode;
 
 	/* Check that this is a block device */
 	if (stat(dev->path, &st) < 0) {
@@ -566,6 +567,19 @@ int ptio_open_dev(struct ptio_dev *dev, mode_t mode)
 	}
 
 	/* Open device */
+	switch (dxfer) {
+	case PTIO_DXFER_TO_DEV:
+		mode = O_RDWR;
+		break;
+	case PTIO_DXFER_NONE:
+	case PTIO_DXFER_FROM_DEV:
+		mode = O_RDONLY;
+		break;
+	default:
+		fprintf(stderr, "Invalid dxfer type\n");
+		return -1;
+	}
+
 	dev->fd = open(dev->path, mode | O_EXCL);
 	if (dev->fd < 0) {
 		fprintf(stderr, "Open %s failed %d (%s)\n",