On Wed, Nov 08, 2006 at 12:01:09AM +0000, Alasdair G Kergon wrote: > On Wed, Nov 08, 2006 at 12:42:02AM +0100, Rafael J. Wysocki wrote: > > On Wednesday, 8 November 2006 00:18, Eric Sandeen wrote: > > > But, how is a stampede of fs-freezers -supposed- to work? I could > > > imagine something like a freezer count, and the filesystem is only > > > unfrozen after everyone has thawed? Or should only one freezer be > > > active at a time... which is what we have now I guess. > > I think it shouldn't be possible to freeze an fs more than once. > > In device-mapper today, the only way to get more than one freeze on the > same device is to use xfs and issue xfs_freeze before creating an lvm snapshot > (or issuing the dmsetup equivalent), and at the moment we tell people not to do > that any more. But it's trivial to detect this condition - if (sb->s_frozen != SB_UNFROZEN) then the filesystem is already frozen and you shouldn't try to freeze it again. It's simple to do, and the whole problem then just goes away.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
