On Thu, Jan 20, 2011 at 6:46 AM, Jeff Moyer <jmoyer@xxxxxxxxxx> wrote: > Jeff Moyer <jmoyer@xxxxxxxxxx> writes: > >> Jan Kara <jack@xxxxxxx> writes: >> >>> But there's the second race I describe making it possible >>> for new IO to be created after io_destroy() has waited for all IO to >>> finish... >> >> Can't that be solved by introducing memory barriers around the accesses >> to ->dead? > > Upon further consideration, I don't think so. > > Given the options, I think adding the synchronize rcu to the io_destroy > path is the best way forward. You're already waiting for a bunch of > queued I/O to finish, so there is no guarantee that you're going to > finish that call quickly. I think synchronize_rcu() is not something to sprinkle around outside very slow paths. It can be done without synchronize_rcu. -- 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
