On Sat, Apr 02, 2022 at 08:26:23PM +0900, Tetsuo Handa wrote: > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=168d578db00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=be9183de0824e4d7 > > dashboard link: https://syzkaller.appspot.com/bug?extid=4f1a237abaf14719db49 > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > This is a known problem, and Christoph does not like a mitigation patch. > https://lkml.kernel.org/r/YgoQBTzb3b0l1SzP@xxxxxxxxxxxxx And this report shows why: your patch makes the lock acquisition in blkdev_fallocate killable. Which would not help with this problem at all, as it does not come through blkdev_fallocate. The problem is that the loop writing actual zeroes to the disk can take forever, and we hold the invalidate_lock over that.
