On Thu, Jul 02, 2020 at 11:52:21AM +0000, Martin Wilck wrote: > On Wed, 2020-03-25 at 17:00 -0500, Benjamin Marzinski wrote: > > On Wed, Mar 25, 2020 at 03:52:55PM -0500, Benjamin Marzinski wrote: > > > On Wed, Mar 25, 2020 at 03:16:50PM +0000, Martin Wilck wrote: > > > > On Tue, 2020-03-24 at 16:03 -0500, Benjamin Marzinski wrote: > > > > > > > > AFAICS, this function has been in libdm since 1.02.111. We > > > > support > > > > 1.02.89 (if all features enabled, otherwise even older). Perhaps > > > > we > > > > should make this function call conditional on the libdm verson? > > > > > > > > But perhaps more importantly, why do we still need to call > > > > dm_lib_release()? AFAICS it's only needed for systems that have > > > > no udev > > > > support for creating device nodes (to call update_devs() via > > > > dm_lib_release()), and we don't support that anymore anyway, do > > > > we? > > > > > > > > Since 26c4bb0, we're always setting the > > > > DM_UDEV_DISABLE_LIBRARY_FALLBACK flag, and the cookie, too > > > > (we aren't setting it for DM_DEVICE_RELOAD, but it isn't needed > > > > for > > > > that, either, since no device nodes need to be created or > > > > removed); so > > > > dm_lib_release() should really have no effect. > > > > > > > > Regards > > > > Martin > > > > > > Good call. I'll redo this patch. > > > > Actually, I've changed my mind. Calling dm_lib_release() lets us > > release > > the memory that device-mapper uses to store all the node ops that it > > was saving up. Without calling dm_lib_release(), AFAICS, that memory > > keeps growing until the daemon exits. > > Sorry for coming back to this so late. I've just stared at the libdm > code again. > > We always set DM_UDEV_DISABLE_LIBRARY_FALLBACK. In the standard CREATE > and REMOVE cases, libdm doesn't stack any operations if this flag is > set. The only exceptions are > > a) RESUME operations with DM_ADD_NODE_ON_RESUME set. This happens > implicity when we create new maps > b) RENAME operations > > In both cases, we call dm_udev_wait() after the libdm operation, which > calls update_devs() and should thus have the same effect as > dm_lib_release(). IOW, I still believe we don't need to call > dm_lib_release() any more. Sure. But can we leave this patch as is, and remove those calls in a different patch? -Ben > Regards, > Martin > > -- > Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107 > SUSE Software Solutions Germany GmbH > HRB 36809, AG Nürnberg GF: Felix > Imendörffer > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
