On Tue 26-01-21 13:34:06, Christoph Hellwig wrote: > On Tue, Jan 26, 2021 at 02:17:52PM +0100, Jan Kara wrote: > > Well, I don't think that "wait until unfrozen" is that strange e.g. for > > Q_SETQUOTA - it behaves like setxattr() or any other filesystem > > modification operation. And IMO it is desirable that filesystem freezing is > > transparent for operations like these. For stuff like Q_QUOTAON, I agree > > that returning EBUSY makes sense but then I'm not convinced it's really > > simpler or more useful behavior... > > If we want it to behave like other syscalls we'll just need to throw in > a mnt_want_write/mnt_drop_write pair. Than it behaves exactly like other > syscalls. Right, we could do that. I'd just note that the "wait until unfrozen" and holding of sb->s_umount semaphore is equivalent to mnt_want_write/mnt_drop_write pair. But I agree mnt_want_write/mnt_drop_write is easier to understand and there's no reason not to use it. So I'm for that simplification in the new syscall. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
