Hello, On Sun, Aug 30, 2015 at 08:30:41AM -0400, Josh Boyer wrote: > Mike and Jeff suggested you be informed of the oops one of our > community members is hitting in Fedora with 4.2-rcX. I thought they > had already sent this upstream to you, but apparently they didn't. > > The latest oops is below. That is with 4.2-rc8. I believe the first > report was against a merge window 4.2 kernel. The full bug report is > here: https://bugzilla.redhat.com/show_bug.cgi?id=1237136 > > I believe Mike and Jeff suspected the cgroup writeback patches. > > josh > > lvm vgchange -a n > /run/lvm/lvmetad.socket: connect failed: No such file or directory > WARNING: Failed to connect to lvmetad. Falling back to internal scanning. > [ 36.157672] BUG: unable to handle kernel NULL pointer dereference > at 0000000000000558 > [ 36.157672] IP: [<ffffffff81389746>] __blkg_lookup+0x26/0x70 ... > [ 36.157672] [<ffffffff8138d14a>] blk_throtl_drain+0x5a/0x110 > [ 36.157672] [<ffffffff8138a108>] blkcg_drain_queue+0x18/0x20 > [ 36.157672] [<ffffffff81369a70>] __blk_drain_queue+0xc0/0x170 > [ 36.157672] [<ffffffff8136a101>] blk_queue_bypass_start+0x61/0x80 > [ 36.157672] [<ffffffff81388c59>] blkcg_deactivate_policy+0x39/0x100 > [ 36.157672] [<ffffffff8138d328>] blk_throtl_exit+0x38/0x50 > [ 36.157672] [<ffffffff8138a14e>] blkcg_exit_queue+0x3e/0x50 > [ 36.157672] [<ffffffff8137016e>] blk_release_queue+0x1e/0xc0 > [ 36.157672] [<ffffffff8139bcba>] kobject_release+0x7a/0x190 > [ 36.157672] [<ffffffff8139bb6f>] kobject_put+0x2f/0x60 > [ 36.157672] [<ffffffff8136a2b1>] blk_cleanup_queue+0x111/0x140 > [ 36.157672] [<ffffffff815f13fc>] cleanup_mapped_device+0xdc/0x100 > [ 36.157672] [<ffffffff815f2311>] __dm_destroy+0x161/0x260 > [ 36.157672] [<ffffffff815f45d3>] dm_destroy+0x13/0x20 > [ 36.157672] [<ffffffff815f9ebd>] dev_remove+0x10d/0x170 > [ 36.157672] [<ffffffff815fa572>] ctl_ioctl+0x232/0x4d0 > [ 36.157672] [<ffffffff815fa823>] dm_ctl_ioctl+0x13/0x20 > [ 36.157672] [<ffffffff8122ebd5>] do_vfs_ioctl+0x295/0x470 > [ 36.157672] [<ffffffff8122ee29>] SyS_ioctl+0x79/0x90 > [ 36.157672] [<ffffffff817750ae>] entry_SYSCALL_64_fastpath+0x12/0x71 I think the offending commit is 776687bce42b ("block, blk-mq: draining can't be skipped even if bypass_depth was non-zero"). It looks like the patch makes shutdown path travel data structure which is already destroyed. Will post the fix soon. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
