On Thu 15-05-14 08:47:25, Ted Tso wrote: > On Thu, May 15, 2014 at 12:01:57PM +0200, Jan Kara wrote: > > I was tracking down a couple of times what the hell is freezing the > > filesystem (and not unfreezing it) and I agree with Mateusz it would be > > nice if we could tell after the fact who froze the fs. Maybe we could store > > that information in superblock and dump it during emergency thaw? > > Saving it in the superblock would require changing a bunch of file > systems. What if we store this information in memory, and print it > out under certain conditions (i.e., after a soft lockup detection, or > upon request of some magic sysrq request)? By 'superblock' I meant 'struct super_block' ;) So we are in agreement I believe. > Or we could create a tunable threshold and print a message after a > file system has been frozen more than a particular specified duration, > with that duration set conservatively to something like 60 or 120 > seconds by default. I was thinking about this as well but all these "warn after X seconds" warnings tend to have quite a few false positives in practice so dumping this in emergency-thaw sysrq handler or exposing the information somewhere in proc (e.g. mountinfo) would look like a better option to me. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
