Re: [PATCH v3 5/7] selftests: add memfd/sealing page-pinning tests

[Hugh Dickins <hughd@google.com>]

On Fri, 13 Jun 2014, David Herrmann wrote:

> Setting SEAL_WRITE is not possible if there're pending GUP users. This
> commit adds selftests for memfd+sealing that use FUSE to create pending
> page-references. FUSE is very helpful here in that it allows us to delay
> direct-IO operations for an arbitrary amount of time. This way, we can
> force the kernel to pin pages and then run our normal selftests.
> 
> Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

I had a number of problems in getting this working (on openSUSE 13.1):
rpm told me I had fuse installed, yet I had to download and install
the tarball to get header files needed; then "make fuse_mnt" told me
to add -D_FILE_OFFSET_BITS=64 to the compile flags; after which I
got "undefined reference to `fuse_main_real'"; but then I tried
"make run_fuse" as root, and it seemed to sort these issues out
for itself, aside from "./run_fuse_test.sh: Permission denied" -
which was within my bounds of comprehension unlike the rest!

No complaint, thanks for providing the test (though I didn't check
the source to convince myself that "DONE" has done what's claimed):
some rainy day someone can get the Makefile working more smoothly,
no need to delay the patchset for this.

Hugh