Hi Yasui-san, On 01/21/2010 07:58 AM +0900, Takahiro Yasui wrote: > Kiyoshi Ueda wrote: >> On 01/20/2010 05:40 AM +0900, Takahiro Yasui wrote: >>> Introduce a target handler, cancel_presuspend, to cancel status changes >>> done by a target specific presuspend handler. >> >> How about using ->resume as a cancelling method? >> Though you have to audit existing targets' ->resume handler, >> I think it's better idea than adding another target handler >> just for this purpose. > <snip> > > I'm afraid that we need to modify each target's resume handler so that > they work properly even after processing presuspend handler but before > postsuspend handler. > > Please let me know if there is some oversight. There is no oversight. Perhaps I should have said 'audit (and modify if necessary)'. If auditing and modifying all targets are difficult, I don't object your approach which adds ->cancel_presuspend. But ->cancel_presuspend should be a subset of ->resume and it should make some code duplication. If ->resume can always restore target state correctly, it may avoid such duplication. Althrough I'm not sure the following idea is really reasonable, I think it should be worth to consider about it: When ->postsuspend is called and the device is really suspended, DMF_SUSPENDED flag is set in md->flags. So targets' ->resume handler can use it to check ->postsuspend had been called or not. Thanks, Kiyoshi Ueda -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
