Bug#854400: systemd: FTBFS if /tmp is an overlayfs

[Michael Biebl]

Am 06.02.2017 um 18:07 schrieb James Cowgill:
> Source: systemd
> Version: 232-15
> Severity: important
> 
> Hi,
> 
> While testing #852811 I discovered that systemd does not build within an
> overlayfs schroot (which all my mips chroots are setup as). Specifically
> the "test-copy" test fails with:
> 
>> FAIL: test-copy
>> ===============
>>
>> test_copy_file
>> test_copy_file_fd
>> test_copy_tree
>> Assertion 'access(f, F_OK) == 0' failed at ../src/test/test-copy.c:136, function test_copy_tree(). Aborting.
>> FAIL test-copy (exit status: 134)
> 
> The assertion is caused by a file not being copied by copy_tree and that
> is in turn caused by this line:
> https://sources.debian.net/src/systemd/232-15/src/basic/copy.c/#L342
> 
> The above line does not copy files if the device of the file is not the
> same as the device of the parent directory, however on an overlayfs
> filesystem this is condition is always true for non-directories.
> 
> From https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt:
>> This approach is 'hybrid' because the objects that appear in the
>> filesystem do not all appear to belong to that filesystem.  In many
>> cases an object accessed in the union will be indistinguishable
>> from accessing the corresponding object from the original filesystem.
>> This is most obvious from the 'st_dev' field returned by stat(2).
>>
>> While directories will report an st_dev from the overlay-filesystem,
>> all non-directory objects will report an st_dev from the lower or
>> upper filesystem that is providing the object.  Similarly st_ino will
>> only be unique when combined with st_dev, and both of these can change
>> over the lifetime of a non-directory object.  Many applications and
>> tools ignore these values and will not be affected.
> 
> Note that this behavior is different from say 'cp -Rx'. cp only checks
> the value of st_dev if the file is a directory. This allows it to work
> correctly with overlayfs.
> http://sources.debian.net/src/coreutils/8.26-2/src/copy.c/?hl=2547#L2547
> 

I think this is a bug in overlayfs.


-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://alioth-lists.debian.net/pipermail/pkg-systemd-maintainers/attachments/20170206/497d8c88/attachment-0002.sig>