Hi list, apologies if I'm at the wrong place, but I think this is dm related (even though in practice the device I'm talking about is using the dm-crypt target). This is my problem: I have a open dm-crypt mapping (LUKS) on which I do perform some block operations (copying). There are no mounted file systems on the copied device handles at any time. Let's say my device is called under /dev/mapper/foobar and I'm writing to that block device. The file descriptor that points to the /dev/mapper/foobar is then closed via close(2). Then I call sync(2). Afterwards I fork/exec the command "dmsetup remove foobar". This yields: device-mapper: remove ioctl on foobar failed: Device or resource busy Command failed And results in return code 1. I'm only getting this behavior with slow disks (i.e. cannot reproduce with a loop device that points to /dev/shm as underlying block device). And I'm guessing there's some buffers/caches still in use (i.e. pending writes) which is why dmsetup returns EBUSY. What I don't understand is why the sync(2) call does not block until all pending writes have been flushed. If I do insert sleep(10) before my "dmsetup remove" call, it works smoothly -- but this is hardly a solution. Do you have any pointers on why this happens and how I can cleanly solve this? Thank you very much, Cheers, Johannes -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
