Messages in this thread | | | Subject | Re: [PATCH v7 08/19] iommu: Implement reserved_regions iommu-group sysfs file | From | Auger Eric <> | Date | Tue, 10 Jan 2017 22:21:28 +0100 |
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Hi Joerg, On 10/01/2017 18:14, Joerg Roedel wrote: > On Tue, Jan 10, 2017 at 05:20:34PM +0100, Auger Eric wrote: >> The /sys/kernel/iommu_groups/n directory seems to be removed before this >> gets called and this may produce a WARNING when devices get removed from >> the group. I intend to remove the call since I have the feeling >> everything gets cleaned up properly. > > A feeling is not enough, please check that in the code.
So my understanding is on group's kobject_release we have: kobject_release |_ kobject_cleanup |_ kobject_del |_ sysfs_remove_dir |_ kernfs_remove |_ _kernfs_remove ../.. |_ ktype release (iommu_group_release)
_kernfs_remove() calls kernfs_put() on all descendant nodes, leading to the whole directory cleanup.
In iommu_group_release I called sysfs_remove_file on the reserved_regions attribute file. My understanding is its job is identifical as what was done previously and the node was already destroyed hence the warning.
sysfs_remove_file |_ sysfs_remove_file_ns |_ kernfs_remove_by_name_ns |_kernfs_remove
So my understanding is it is safe to remove it.
Thanks
Eric > > > Joerg > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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