Hi,
On 08/31/2018 10:22 AM, AKASHI Takahiro wrote:
Hi Tuomas,
Thank you for interesting pointers.
On Thu, Aug 30, 2018 at 01:56:41PM +0300, Tuomas Tynkkynen wrote:
Hi Heinrich, Takahiro
On 08/30/2018 01:26 PM, AKASHI Takahiro wrote:
On Thu, Aug 30, 2018 at 12:01:32PM +0200, Heinrich Schuchardt wrote:
On 08/30/2018 08:52 AM, AKASHI Takahiro wrote:
On Wed, Aug 29, 2018 at 11:36:51PM +0200, Heinrich Schuchardt wrote:
...
Using sudo for me is a NO-NO. I will not run any test that uses sudo.
So this means that you have never tested file system using test-fs.sh.
Since my script is logically "general", it can, if we want, run against other file systems as well. "sudo mount" is the only solution for those cases.
There are two general non-root implementations that I know of:
- http://libguestfs.org/ which IIRC launches a small Linux VM in QEMU to do the filesystem accesses. I am not sure if the performance would be acceptable without KVM (which I assume we don't have in Travis).
I didn't dig into this tool, but if it is all about VM on qemu, the discussion here, whether we should be allowed to use sudo or not, would be pointless as we can do whatever we want to do under VM.
But that's exactly what was wanted - that the user running the tests for U-Boot doesn't need to have sudo access on their build machine.
BTW I briefly benchmarked this on a AWS free-tier machine (no KVM available), and copying a 2G file onto an ext4 partition took:
- 33s natively (sudo mount -o loop fs.img /mnt; sudo cp bigfile /mnt/; sudo umount /mnt) - 2m 44s with guestfs (guestfish add fs.img : run : mount /dev/sda / : copy-in bigfile /)
so a 80% slowdown for things like Travis CI but still not unbearably slow. I'm assuming here that it will run much faster with KVM and that developers usually have KVM-capable machines so this shouldn't affect developers too badly.
- https://github.com/lkl/linux which is a port of Linux to run in userspace as a library. It comes with tools like cptofs and lklfuse to access any filesystem Linux has a driver for.
It appears to be a kind of libos or unikernel, or rather, resembles a sandbox of u-boot?
Correct.
Sadly lkl isn't packaged in many distros.
Too bad.
Yes, I'd say libguestfs is the most promising solution so far.