On Thu, Dec 22, 2016 at 11:15 AM, Jan Kara <jack@xxxxxxx> wrote: > fanotify wants to drop fsnotify_mark_srcu lock when waiting for response > from userspace so that the whole notification subsystem is not blocked > during that time. This patch provides a framework for safely getting > mark reference for a mark found in the object list which pins the mark > in that list. We can then drop fsnotify_mark_srcu, wait for userspace > response and then safely continue iteration of the object list once we > reaquire fsnotify_mark_srcu. > > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- ... > + /* > + * Now that both marks are pinned by refcount we can drop SRCU lock. > + * Marks can still be removed from the list but because of refcount > + * they cannot be destroyed and we can safely resume the list iteration > + * once userspace returns. > + */ Sorry, forgot to comment on this. "Marks can still be removed from the list ... ... and we can safely resume the list iteration" I suppose you are plannig to get the mechanics right, by replacing hlist_del_init() with just __hlist_del() ?? but this sentence is confusing. Usually, it wouldn't be safe to resume iteration if items may have been removed, so perhaps rephrase or clarify. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
