Hi, I noticed that a freshly booted 4.8-rc4 kernel gives the following kernel messages a few times: BUG: sleeping function called from invalid context at fs/dcache.c:757 in_atomic(): 1, irqs_disabled(): 0, pid: 8431, name: automount 1 lock held by automount/8431: #0: (&(&sbi->fs_lock)->rlock){+.+...}, at: [<ffffffff81345736>] autofs4_expire_indirect+0x136/0x2d0 CPU: 4 PID: 8431 Comm: automount Not tainted 4.8.0-rc4-test2+ #210 Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A12 01/10/2013 0000000000000000 ffff8801843efc30 ffffffff813bbdd3 ffff88019e6500c0 ffffffff81a330b6 ffff8801843efc58 ffffffff810a3052 ffffffff81a330b6 00000000000002f5 0000000000000000 ffff8801843efc80 ffffffff810a3149 Call Trace: [<ffffffff813bbdd3>] dump_stack+0x86/0xc3 [<ffffffff810a3052>] ___might_sleep+0x142/0x1f0 [<ffffffff810a3149>] __might_sleep+0x49/0x80 [<ffffffff81260b17>] ? dput+0x37/0x400 [<ffffffff81260b26>] dput+0x46/0x400 [<ffffffff8126c96d>] ? lookup_mnt+0x14d/0x1d0 [<ffffffff8124ff54>] ? follow_down_one+0x14/0x60 [<ffffffff8124ff67>] follow_down_one+0x27/0x60 [<ffffffff81344da2>] autofs4_mount_busy+0x32/0x110 [<ffffffff81345081>] should_expire+0x51/0x3d0 [<ffffffff81345790>] autofs4_expire_indirect+0x190/0x2d0 [<ffffffff81345fa0>] ? autofs_dev_ioctl_askumount+0x30/0x30 [<ffffffff81345bb4>] autofs4_do_expire_multi+0x94/0xb0 [<ffffffff81345fa0>] ? autofs_dev_ioctl_askumount+0x30/0x30 [<ffffffff81345fbf>] autofs_dev_ioctl_expire+0x1f/0x30 [<ffffffff81346679>] _autofs_dev_ioctl+0x2b9/0x350 [<ffffffff81346723>] autofs_dev_ioctl+0x13/0x20 [<ffffffff8125af54>] do_vfs_ioctl+0x94/0x690 [<ffffffff8126820d>] ? __fget+0x10d/0x200 [<ffffffff81268105>] ? __fget+0x5/0x200 [<ffffffff8125b5c9>] SyS_ioctl+0x79/0x90 [<ffffffff8170ef00>] entry_SYSCALL_64_fastpath+0x23/0xc1 I don't remember of a similar stack trace in the past, so if any, it can be a regression in 4.8 kernel. But I cannot say it in 100%, as this looks spontaneous, nor I would be able to reproduce it at the next boot... thanks, Takashi -- To unsubscribe from this list: send the line "unsubscribe autofs" in