I ran all kernel selftests on some test machine, and stumbled upon cachestat failing (among others). These patches fix the run on older kernels and when the current directory is on a tmpfs instance.
I dropped the first two fix patches from v1, since Shuah applied those already. [PATCH v2 1/2] is almost the same as [PATCH 3/3] from v1, but using the proper skip function from kselftest.h. I am not sure if Shuah applied that already, if yes, it's not a big problem, the output is the same.
Patch 2/2 implements the tmpfs detection that Nhat suggested the last time (many thanks for pointing me to statfs and the magics!).
Cheers, Andre
Andre Przywara (2): selftests: cachestat: test for cachestat availability selftests: cachestat: catch failing fsync test on tmpfs
.../selftests/cachestat/test_cachestat.c | 80 +++++++++++++++---- 1 file changed, 65 insertions(+), 15 deletions(-)