On Mon, 20 Apr 2009, Kiyoshi Ueda wrote: > Hi Alasdair, Mikulas, > > On 2009/04/17 22:22 +0900, Alasdair G Kergon wrote: > > On Fri, Apr 17, 2009 at 01:57:02PM +0900, Kiyoshi Ueda wrote: > >> 1. The semantics of flush suspend has been changed. > > > > We absolutely must complete any I/O issued as a result of the lock_fs() > > call in dm_suspend(). > > I think that lock_fs() waits for I/O to complete, so no semantics change > in case of LOCKFS && FLUSH. (All I/O issued from lock_fs() are flushed.) True. It waits, so there's no problem with it. > But in case of NO_LOCKFS && FLUSH, the semantics is changed: > from: I/Os submitted before the suspend invocation are flushed > to: I/Os submitted even before the suspend invocation may not be flushed > > I have no idea whether someone gets real damage by this semantics change. I have no idea whether it hurts too. I think it doesn't hurt because suspend may come only from ioctl and that ioctl syscall doesn't submit any requests prior to suspend. It would be trivial to fix, but I don't know about any case where it could cause a bug. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
