On Wed 2016-07-20 16:11:16, Charles Gong wrote: > "SYSRQ + J" triggers a call to emergency_thaw_all(). Currently, this > is an infinite loop. Once we trigger it, we'll need to do a hard > power-cycle. There are users reporting this bug from 2012 to 2016, for > example, at https://bugzilla.kernel.org/show_bug.cgi?id=47741. > > This happens because thaw_bdev() fails to return -EINVAL in the > non-frozen case, so fix it so that do_one_thaw() can recognize this case > and quit from looping. I checked that none of the other thaw_bdev() > callers check the return value. > > The regression was introduced in commit 4504230a7156 ("freeze_bdev: grab > active reference to frozen superblocks"). > > Reviewed-by: Chris Mason <c...@fb.com> > Signed-off-by: Charles Gong <cgg...@fb.com>
Acked-by: Pavel Machek <pa...@ucw.cz> (even magic should be finite...) -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
