On Mon, Apr 30, 2018 at 02:31:30PM +1000, NeilBrown wrote: > list_for_each_entry_from_rcu() is an RCU version of > list_for_each_entry_from(). It walks a linked list under rcu > protection, from a given start point. > > It is similar to list_for_each_entry_continue_rcu() but starts *at* > the given position rather than *after* it. > > Naturally, the start point must be known to be in the list. I'd suggest giving an explicit advisory comment to clarify and suggest correct usage: "This would typically require either that you obtained the node from a previous walk of the list in the same RCU read-side critical section, or that you held some sort of non-RCU reference (such as a reference count) to keep the node alive *and* in the list." (Feel free to wordsmith the exact wording, but something like that seems like it would help people understand how to use this correctly, and make it less likely that they'd use it incorrectly.) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
