On Tue, Sep 22, 2020 at 11:16:42AM +0200, Jan Kara wrote: > Looks like btrfs issue. Adding relevant people to CC. Thanks. > On Mon 21-09-20 02:32:21, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 325d0eab Merge branch 'akpm' (patches from Andrew) > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=102425d9900000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=b12e84189082991c > > dashboard link: https://syzkaller.appspot.com/bug?extid=84a0634dc5d21d488419 > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+84a0634dc5d21d488419@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ====================================================== > > WARNING: possible circular locking dependency detected > > 5.9.0-rc5-syzkaller #0 Not tainted > > ------------------------------------------------------ > > syz-executor.0/6878 is trying to acquire lock: > > ffff88804c17d780 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_put+0x30/0x520 fs/block_dev.c:1804 > > > > but task is already holding lock: > > ffff8880908cfce0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: close_fs_devices.part.0+0x2e/0x800 fs/btrfs/volumes.c:1159 > > > > which lock already depends on the new lock. That matches what "btrfs: move btrfs_rm_dev_replace_free_srcdev outside of all locks" fixes, among other syzbot reports. On the way to master: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git/commit/?h=next-fixes&id=d1db82c9a34451e8c0288315b51d9a67fb8eff95
