From: Jason Gunthorpe <[email protected]> The device creator is supposed to use the dev.groups value to add sysfs files before device_add is called, not call sysfs_create_files() after device_add() returns. This creates a race with uevent delivery where the extra attribute will not be visible.
This was being done because the groups had been co-opted by the mdev driver, now that prior patches have moved the driver's groups to the struct device_driver the dev.group is properly free for use here. Signed-off-by: Jason Gunthorpe <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> --- drivers/vfio/mdev/mdev_core.c | 1 + drivers/vfio/mdev/mdev_private.h | 2 ++ drivers/vfio/mdev/mdev_sysfs.c | 19 ++++++++++--------- 3 files changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 19a20ff420b7f..b8b9e7911e559 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -269,6 +269,7 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid) mdev->dev.parent = parent->dev; mdev->dev.bus = &mdev_bus_type; mdev->dev.release = mdev_device_release; + mdev->dev.groups = mdev_device_groups; mdev->type = type; /* Pairs with the put in mdev_device_release() */ kobject_get(&type->kobj); diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 5a7ffd4e770fd..7c9fc79f3d838 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -32,6 +32,8 @@ struct mdev_type { unsigned int type_group_id; }; +extern const struct attribute_group *mdev_device_groups[]; + #define to_mdev_type_attr(_attr) \ container_of(_attr, struct mdev_type_attribute, attr) #define to_mdev_type(_kobj) \ diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c index 5a3873d1a275a..0ccfeb3dda245 100644 --- a/drivers/vfio/mdev/mdev_sysfs.c +++ b/drivers/vfio/mdev/mdev_sysfs.c @@ -244,11 +244,20 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_WO(remove); -static const struct attribute *mdev_device_attrs[] = { +static struct attribute *mdev_device_attrs[] = { &dev_attr_remove.attr, NULL, }; +static const struct attribute_group mdev_device_group = { + .attrs = mdev_device_attrs, +}; + +const struct attribute_group *mdev_device_groups[] = { + &mdev_device_group, + NULL +}; + int mdev_create_sysfs_files(struct mdev_device *mdev) { struct mdev_type *type = mdev->type; @@ -262,15 +271,8 @@ int mdev_create_sysfs_files(struct mdev_device *mdev) ret = sysfs_create_link(kobj, &type->kobj, "mdev_type"); if (ret) goto type_link_failed; - - ret = sysfs_create_files(kobj, mdev_device_attrs); - if (ret) - goto create_files_failed; - return ret; -create_files_failed: - sysfs_remove_link(kobj, "mdev_type"); type_link_failed: sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev)); return ret; @@ -280,7 +282,6 @@ void mdev_remove_sysfs_files(struct mdev_device *mdev) { struct kobject *kobj = &mdev->dev.kobj; - sysfs_remove_files(kobj, mdev_device_attrs); sysfs_remove_link(kobj, "mdev_type"); sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev)); } -- 2.30.2
