On Thu, 2017-08-24 at 11:07 +0200, Christoph Hellwig wrote: > On Wed, Aug 23, 2017 at 02:39:57PM -0700, Bart Van Assche wrote: > > Only annotate pointers that are shared across threads with __rcu. > > Use rcu_dereference() when dereferencing an RCU pointer. Protect > > also the RCU pointer dereferences when freeing RCU pointers. This > > patch suppresses about twenty sparse complaints about the vpd_pg8[03] > > pointers. > > Shouldn't the kfrees be kfree_rcu? or where else is the rcu protection > for them? Hello Christoph, My understanding of the SCSI VPD code is as follows: * rcu_read_lock() / rcu_read_unlock() is used to prevent that another thread updates a VPD buffer while it is being read. * All code that either updates or reads a VPD buffer holds a reference on the SCSI device that buffer is associated with. That is why I think it is not needed to use kfree_rcu() in scsi_device_dev_release_usercontext(). Bart.
