On 19 December 2016 at 10:24, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Sun, Dec 18, 2016 at 06:57:27PM +0000, Sami Kerola wrote: >> An attempt to freeze a filesystem that does not support such operation is >> reported as EOPNOTSUPP to user. Running unfreeze to the same filesystem >> returns EINVAL. Later is a little misleading, users can mix that message >> with return value from unfreezing when filesystem is not frozen. > > This is going to break gfs2 with it's odd ->that_super method. Thank you for feedback, there's just one small problem with it. I don't quite understand the breakage. Proposed change uses similar logic as ioctl_fsfreeze()[1] and it works fine. If I am not entirely mistaking freeze and thaw hooks where added[2] to avoid issues with gfs2. And looking gfs2 super_operations init[3] does not make me any wiser what might be wrong. Maybe feedback had typo s/that_super/thaw_super/[4]. But even then it is unclear to me how a null could cause breakage. [1] https://github.com/torvalds/linux/blob/master/fs/ioctl.c#L553 [2] https://github.com/torvalds/linux/commit/48b6bca6b7b8309697fc8a101793befe92d249d9 [3] https://github.com/torvalds/linux/blob/master/fs/gfs2/super.c#L1683 [4] https://github.com/torvalds/linux/blob/master/fs/super.c#L1446 -- Sami Kerola http://www.iki.fi/kerolasa/ -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html