fb6c082460
syscall.Unmount failed sometimes when user interrupted exporting, for example a Ctrl-C, or pipe to commands which closed the pipe early, like "docker export <container_name> | file -"; this syscall.Unmount could sometimes return EBUSY and didn't actually umount the filesystem; which would cause a following export command fail to mount; change to lazy Unmount with MNT_DETACH can fix the problem, this is the same behavior as in Shutdown; ```text time="2015-01-03T21:27:26Z" level=error msg="Warning: error unmounting device 34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e: device or resource busy" ``` ``` $ docker export thirsty_ardinghelli | file - /dev/stdin: POSIX tar archive time="2015-01-03T21:58:17Z" level=fatal msg="write /dev/stdout: broken pipe" $ docker export thirsty_ardinghelli time="2015-01-03T21:54:33Z" level=fatal msg="Error: thirsty_ardinghelli: Error getting container 34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e from driver devicemapper: Error mounting '/dev/mapper/docker-253:0-3148372-34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e' on '/var/lib/docker/devicemapper/mnt/34a3e77cdbca17ceffd0636aee0415bb412996adb12360bfe2585ce30467fa8e': device or resource busy" ``` Signed-off-by: Derek Che <drc@yahoo-inc.com> Upstream-commit: 9bbed5ab4ceaff5e78c21f0fa2d84de5ffd41f94 Component: engine