任务由于挂起的设备映射器设备而阻止

Issue

• 任务被挂起的任务 watchdog 报告为 blocked：

Apr 26 02:25:01 kernel: INFO: task lvcreate:15067 blocked for more than 120 seconds.
Apr 26 02:25:01 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Apr 26 02:25:01 kernel: lvcreate      D 0000000000000000     0 15067  15066 0x00000080
Apr 26 02:25:01 kernel: ffff8801b385bac8 0000000000000082 ffff8801b385ba88 ffffffffa00043fc
Apr 26 02:25:01 kernel: ffff8801b385ba98 00000000628b5d4f ffff8801b385bab8 ffff880194e7d180
Apr 26 02:25:01 kernel: ffff88061fd51ab8 ffff8801b385bfd8 000000000000fb88 ffff88061fd51ab8
Apr 26 02:25:01 kernel: Call Trace:
Apr 26 02:25:01 kernel: [<ffffffffa00043fc>] ? dm_table_unplug_all+0x5c/0x100 [dm_mod]
Apr 26 02:25:01 kernel: [<ffffffff810a2431>] ? ktime_get_ts+0xb1/0xf0
Apr 26 02:25:01 kernel: [<ffffffff8150e8c3>] io_schedule+0x73/0xc0
Apr 26 02:25:01 kernel: [<ffffffff811bed0e>] __blockdev_direct_IO_newtrunc+0x6de/0xb30
Apr 26 02:25:01 kernel: [<ffffffff811bf1be>] __blockdev_direct_IO+0x5e/0xd0
Apr 26 02:25:01 kernel: [<ffffffff811bb590>] ? blkdev_get_blocks+0x0/0xc0
Apr 26 02:25:01 kernel: [<ffffffff811bc657>] blkdev_direct_IO+0x57/0x60
Apr 26 02:25:01 kernel: [<ffffffff811bb590>] ? blkdev_get_blocks+0x0/0xc0
Apr 26 02:25:01 kernel: [<ffffffff8111bcab>] generic_file_aio_read+0x6bb/0x700
Apr 26 02:25:01 kernel: [<ffffffff812235d1>] ? avc_has_perm+0x71/0x90
Apr 26 02:25:01 kernel: [<ffffffff811bd029>] ? __blkdev_get+0x1a9/0x3b0
Apr 26 02:25:01 kernel: [<ffffffff811bbba3>] blkdev_aio_read+0x53/0xc0
Apr 26 02:25:01 kernel: [<ffffffff811811aa>] do_sync_read+0xfa/0x140
Apr 26 02:25:01 kernel: [<ffffffff81096da0>] ? autoremove_wake_function+0x0/0x40
Apr 26 02:25:01 kernel: [<ffffffff810d9e7d>] ? audit_filter_rules+0x2d/0xdd0
Apr 26 02:25:01 kernel: [<ffffffff81228ffb>] ? selinux_file_permission+0xfb/0x150
Apr 26 02:25:01 kernel: [<ffffffff8121bed6>] ? security_file_permission+0x16/0x20
Apr 26 02:25:01 kernel: [<ffffffff81181a95>] vfs_read+0xb5/0x1a0
Apr 26 02:25:01 kernel: [<ffffffff81181bd1>] sys_read+0x51/0x90
Apr 26 02:25:01 kernel: [<ffffffff810dc685>] ? __audit_syscall_exit+0x265/0x290
Apr 26 02:25:01 kernel: [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b