prev_mergeable   1169 fs/btrfs/ioctl.c 	bool prev_mergeable = true;
prev_mergeable   1191 fs/btrfs/ioctl.c 		prev_mergeable = false;
prev_mergeable   1199 fs/btrfs/ioctl.c 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))