[PATCH 1/2] s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request

Stefan Haberland
2025-09-25T15:47:17Z

From: Jaehoon Kim <jhkim@linux.ibm.com>

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 <sth@linux.ibm.com>
Cc: stable@vger.kernel.org #6.11+
Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
drivers/s390/block/dasd.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 506a947d00a5..6224ba412623 100644
--- a/drivers/s390/block/dasd.c
+++ b/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;
}
/*
--
2.48.1