fallocate fails with No such file or directory

[Sean McCully]

preallocate_images=space

fallocate fails with No such file or directory. Not sure how this is supposed to work, but fallocate fails because disk.fallocate_test file does not exist.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/188249

[Sean McCully (sean-mccully)]

Apparently this wasn't clear in the bug report that fallocate expects the file to exist,

http://git.kernel.org/cgit/utils/util-linux/util-linux.git/tree/sys-utils/fallocate.c#n321
http://git.kernel.org/cgit/utils/util-linux/util-linux.git/tree/sys-utils/fallocate.c#n371

This can be validated on the command line,

$ /usr/bin/fallocate -n -l 1 /tmp/test_file.fallocate

2015-06-29 02:58:39.425 DEBUG oslo_concurrency.processutils [req-6b576698-dfcd-4bd9-9166-0fcc22180794 None None] CMD "fallocate -n -l 1 /opt/openstack/nova/instances/80ebc3ae-f005-4c6c-9a78-33664df5c78f/disk.fallocate_test" returned: 0 in 0.036s

[OpenStack Infra (hudson-openstack)]

Change abandoned by Michael Still (<email address hidden>) on branch: master
Review: https://review.openstack.org/188249
Reason: This patch is quite old, so I am abandoning it to keep the review queue manageable. Feel free to restore the change if you're still interested in working on it.