linux-kernel - [PATCH v4 2/2] vfio/mdev: Re-order sysfs attribute creation

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Date:   Fri, 18 May 2018 13:10:35 -0600
From:   Alex Williamson <alex.williamson@...hat.com>
To:     kwankhede@...dia.com
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        alex.williamson@...hat.com, cohuck@...hat.com, pasic@...ux.ibm.com
Subject: [PATCH v4 2/2] vfio/mdev: Re-order sysfs attribute creation

There exists a gap at the end of mdev_device_create() where the device
is visible to userspace, but we're not yet ready to handle removal, as
triggered through the 'remove' attribute.  We handle this properly in
mdev_device_remove() with an -EAGAIN return, but we can marginally
reduce this gap by adding this attribute as a final step of our sysfs
setup.

Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
---
 drivers/vfio/mdev/mdev_sysfs.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 802df210929b..249472f05509 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -257,24 +257,24 @@ int  mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
 {
 	int ret;
 
-	ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
-	if (ret)
-		return ret;
-
 	ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
 	if (ret)
-		goto device_link_failed;
+		return ret;
 
 	ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
 	if (ret)
 		goto type_link_failed;
 
+	ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
+	if (ret)
+		goto create_files_failed;
+
 	return ret;
 
+create_files_failed:
+	sysfs_remove_link(&dev->kobj, "mdev_type");
 type_link_failed:
 	sysfs_remove_link(type->devices_kobj, dev_name(dev));
-device_link_failed:
-	sysfs_remove_files(&dev->kobj, mdev_device_attrs);
 	return ret;
 }