s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request

Currently, if CCW request creation fails with -EINVAL, the DASD driver
returns BLK_STS_IOERR to the block layer.

This can happen, for example, when a user-space application such as QEMU
passes a misaligned buffer, but the original cause of the error is
masked as a generic I/O error.

This patch changes the behavior so that -EINVAL is returned as
BLK_STS_INVAL, allowing user space to properly detect alignment issues
instead of interpreting them as I/O errors.

Reviewed-by: Stefan Haberland <[email protected]>
Cc: [email protected] #6.11+
Signed-off-by: Jaehoon Kim <[email protected]>
Signed-off-by: Stefan Haberland <[email protected]>

Author: Jaehoon Kim

drivers/s390/block/dasd.c

@@ -3114,12 +3114,14 @@ static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
 		    PTR_ERR(cqr) == -ENOMEM ||
 		    PTR_ERR(cqr) == -EAGAIN) {
 			rc = BLK_STS_RESOURCE;
-			goto out;
+		} else if (PTR_ERR(cqr) == -EINVAL) {
+			rc = BLK_STS_INVAL;
+		} else {
+			DBF_DEV_EVENT(DBF_ERR, basedev,
+				      "CCW creation failed (rc=%ld) on request %p",
+				      PTR_ERR(cqr), req);
+			rc = BLK_STS_IOERR;
 		}
-		DBF_DEV_EVENT(DBF_ERR, basedev,
-			      "CCW creation failed (rc=%ld) on request %p",
-			      PTR_ERR(cqr), req);
-		rc = BLK_STS_IOERR;
 		goto out;
 	}
 	/*