Hello, On Thu, Dec 17, 2020 at 07:48:49PM +0800, Ian Kent wrote: > > What could be done is to make the kernfs node attr_mutex > > a pointer and dynamically allocate it but even that is too > > costly a size addition to the kernfs node structure as > > Tejun has said. > > I guess the question to ask is, is there really a need to > call kernfs_refresh_inode() from functions that are usually > reading/checking functions. > > Would it be sufficient to refresh the inode in the write/set > operations in (if there's any) places where things like > setattr_copy() is not already called? > > Perhaps GKH or Tejun could comment on this?
My memory is a bit hazy but invalidations on reads is how sysfs namespace is implemented, so I don't think there's an easy around that. The only thing I can think of is embedding the lock into attrs and doing xchg dance when attaching it. Thanks. -- tejun
