It does, even for reading (cat /dev/nvme0n1 > /dev/null). As per changelog: 1.5.2 - 10 February 2014 allow --watchfd to look at block devices You can

It does, even for reading (cat /dev/nvme0n1 > /dev/null). As per changelog: 1.5.2 - 10 February 2014 allow --watchfd to look at block devices You can see the position in /proc/<pid>/fdinfo/<num>