Hi

On Wed, Jul 16, 2014 at 12:08 PM, Hugh Dickins [off-list ref] wrote:

On Fri, 13 Jun 2014, David Herrmann wrote:

quoted

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 <redacted>

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.

_FILE_OFFSET_BITS=64 makes sense. I added it. The "undefined ref"
thing doesn't make sense to me and I cannot reproduce it. I will see
what I can do.

The "Permission denied" obviously just requires access to /dev/fuse,
as you figured out yourself.

Thanks
David

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>