[PATCH v7 04/12] hv: Use driver_set_override() instead of open-coding

Krzysztof Kozlowski
2022-04-19T11:35:27Z

Use a helper to set driver_override to the reduce amount of duplicated
code. Make the driver_override field const char, because it is not
modified by the core and it matches other subsystems.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
drivers/hv/vmbus_drv.c | 28 ++++------------------------
include/linux/hyperv.h | 6 +++++-
2 files changed, 9 insertions(+), 25 deletions(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 14de17087864..607e40aba18e 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -575,31 +575,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
- char *driver_override, *old, *cp;
-
- /* We need to keep extra room for a newline */
- if (count >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, count, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
-
- cp = strchr(driver_override, '\n');
- if (cp)
- *cp = '\0';
-
- device_lock(dev);
- old = hv_dev->driver_override;
- if (strlen(driver_override)) {
- hv_dev->driver_override = driver_override;
- } else {
- kfree(driver_override);
- hv_dev->driver_override = NULL;
- }
- device_unlock(dev);
+ int ret;

- kfree(old);
+ ret = driver_set_override(dev, &hv_dev->driver_override, buf, count);
+ if (ret)
+ return ret;

return count;
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index fe2e0179ed51..12e2336b23b7 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1257,7 +1257,11 @@ struct hv_device {
u16 device_id;

struct device device;
- char *driver_override; /* Driver name to force a match */
+ /*
+ * Driver name to force a match. Do not set directly, because core
+ * frees it. Use driver_set_override() to set or clear it.
+ */
+ const char *driver_override;

struct vmbus_channel *channel;
struct kset *channels_kset;
--
2.32.0