On Thu, Sep 17, 2015 at 07:58:24AM -0400, Jeff Layton wrote: > In order to allow the client to make a sane determination of what > happened with racing LAYOUTGET/LAYOUTRETURN/CB_LAYOUTRECALL calls, we > must ensure that the seqids return accurately represent the order of > operations. The simplest way to do that is to ensure that operations on > a single stateid are serialized. > > This patch adds a mutex to the layout stateid, and locks it when > checking the layout stateid's seqid. The mutex is held over the entire > operation and released after the seqid is bumped. > > Note that in the case of CB_LAYOUTRECALL we must move the increment of > the seqid and setting into a new cb "prepare" operation. The lease > infrastructure will call the lm_break callback with a spinlock held, so > and we can't take the mutex in that codepath. I can't say I like the long running mutex all that much. What kinds of reproducers do you have where the current behavior causes problems? -- 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
