On Tue, Jul 01, 2008 at 04:10:26AM -0400, Christoph Hellwig wrote: > I still disagree with this whole patch. Same here - if you want a timeout, what stops you from implementing it in a userspace process? If your concern is that the process might die without thawing the filesystem, take a look at the userspace LVM/multipath code for ideas - lock into memory, disable OOM killer, run from ramdisk etc. In practice, those techniques seem to be good enough. > call can hang and this would be theoretically useful is when the > filesystem is already frozen by someone else, but this should be fixed > by refusing to do the second freeze, as suggested in my comment to patch > 1. Similarly if a device-mapper device is involved, how should the following sequence behave - A, B or C? 1. dmsetup suspend (freezes) 2. FIFREEZE 3. FITHAW 4. dmsetup resume (thaws) A: 1 succeeds, freezes 2 succeeds, remains frozen 3 succeeds, remains frozen 4 succeeds, thaws B: 1 succeeds, freezes 2 fails, remains frozen 3 shouldn't be called because 2 failed but if it is: succeeds, thaws 4 succeeds (already thawed, but still does the device-mapper parts) C: 1 succeeds, freezes 2 fails, remains frozen 3 fails (because device-mapper owns the freeze/thaw), remains frozen 4 succeeds, thaws Alasdair -- agk@xxxxxxxxxx -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
