[kbuild-all] Re: [PATCH v2] ovl: provide real_file() and overlayfs get_unmapped_area()

On Wed, Jun 10, 2020 at 05:13:52PM -0700, Mike Kravetz wrote: > To address this issue, > - Add a new file operation f_real while will return the underlying file. > Only overlayfs provides a function for this operation. > - Add a new routine real_file() which can be used by core code get an > underlying file. > - Update is_file_hugepages to get the real file. Egads... So to find out whether it's a hugetlb you would * check if a method is NULL * if not, call it * ... and check if the method table of the result is hugetlbfs one? Here's a radical suggestion: FMODE_HUGEPAGES. Just have it set by ->open() and let is_file_hugepages() check it. In ->f_mode. And make the bloody hugetlbfs_file_operations static, while we are at it.

while (file->f_op == &ovl_file_operations) file = file->private_data; return file;