zfsonlinux/zfs — pull request #1508 by ryao (2013-06-08 07:44:23+00:00)
Title: Do not block in vdev_disk_io_flush()

vdev_disk_io_flush() currently uses GFP_KERNEL, which can block on
swap operations. If we are doing swap operations on a zvol and we block
in vdev_disk_io_flush(), the system will deadlock.

Signed-off-by: Richard Yao