On Thu 15-08-19 15:18:45, Jeff Layton wrote: > On Wed, 2019-08-14 at 19:46 +0200, Jan Kara wrote: > > Resending to proper Jeff's address... > > > > On Wed 14-08-19 19:33:45, Jan Kara wrote: > > > Hello Jeff, > > > > > > we've got a report from user > > > (https://bugzilla.suse.com/show_bug.cgi?id=1145007) wondering why his fstab > > > entry (for root filesystem!) using 'mand' mount option stopped working. > > > Now I understand your rationale in 9e8925b67a "locks: Allow disabling > > > mandatory locking at compile time" but I guess there's some work to do wrt > > > documentation. At least mount(8) manpage could mention that mandatory > > > locking is broken and may be disabled referencing the rationale in fcntl > > > manpage? Or the kernel could mention something in the log about failing > > > mount because of 'mand' mount option? What do you think? Because it took > > > me some code searching to understand why the mount is actually failing > > > which we can hardly expect from a normal sysadmin... > > > > > > Honza > > Wow, I think this is the first actual user fallout we've ever had from > that change! Why was he setting that option? Does he actually use > mandatory locking? Yeah, reportedly they had an application that required mandatory locking. But they don't use it anymore so they just removed the mount option. > I think a pr_notice() or pr_warn() at mount time when someone tries to > use it sounds like a very reasonable thing to do. Perhaps we can just > stick one in may_mandlock()? Yeah, sounds reasonable to me. > I'll draft up a patch, and also update > Documentation/filesystems/mandatory-locking.txt with the current > situation. Thanks! Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
