15007b4e2b
setmntent() doesn't support root_fd, but manual parsing of /proc/mounts is fragile, and actually buggy for very long mount lines (see open-mpi/hwloc#142 (comment)). Since we only openat("/proc/mounts") there, just manually concatenate the fsroot_path and use setmntent(). Thanks to Nathan Hjelm for the report. (Cherry-picked from open-mpi/hwloc@d2d07b9a22) Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>