Re: [PATCH 1/2] kernfs: dont take i_lock on inode attr read

[Tejun Heo]

On Tue, Oct 18, 2022 at 10:32:42AM +0800, Ian Kent wrote:
> The kernfs write lock is held when the kernfs node inode attributes
> are updated. Therefore, when either kernfs_iop_getattr() or
> kernfs_iop_permission() are called the kernfs node inode attributes
> won't change.
> 
> Consequently concurrent kernfs_refresh_inode() calls always copy the
> same values from the kernfs node.
> 
> So there's no need to take the inode i_lock to get consistent values
> for generic_fillattr() and generic_permission(), the kernfs read lock
> is sufficient.
> 
> Signed-off-by: Ian Kent <raven@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

-- 
tejun