BLKDEV_ZERO_NOUNMAP
if (flags & BLKDEV_ZERO_NOUNMAP)
flags = BLKDEV_ZERO_NOUNMAP;
BLKDEV_ZERO_NOUNMAP | BLKDEV_ZERO_KILLABLE);
(flags & EE_TRIM) ? 0 : BLKDEV_ZERO_NOUNMAP);
GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);