bug#8091: fiemap_capable_ misbehaves in a chroot

[Adam Sampson]

Hi,

A minor bug in the testsuite in coreutils 8.10...

I package software in a chroot. At the moment, my chroot doesn't contain
an mtab file, which means df can't tell what type the filesystem is:

$ df -T /
Filesystem    Type   1K-blocks      Used Available Use% Mounted on
-                -   288370908  90872412 194568804  32% /

The fiemap_capable_ function in tests/init.cfg uses df to tell whether
the filesystem it's running on supports fiemap, by asking it to only
list filesystems that it knows are fiemap-capable using -t. However, the
selected_fstype function in df.c will always include filesystems that it
doesn't know the type of, even when -t is specified:

$ df -T -t blahfs /
Filesystem    Type   1K-blocks      Used Available Use% Mounted on
-                -   288370908  90872400 194568816  32% /

The result is that fiemap_capable_ assumes my chrooted filesystem
supports fiemap when it doesn't, so the tests that use it fail.

I'm not sure at this point whether df -t is doing the wrong thing or
fiemap_capable_ is using it incorrectly. Any thoughts?

Thanks very much,

-- 
Adam Sampson <address@hidden>                         <http://offog.org/>