next: lsns: issues with NSFS detection

[t-8ch]

1. Meson does not set HAVE_LINUX_NSFS_H
2. Not all symbols from linux/nsfs.h are guarded with HAVE_LINUX_NSFS_H:

cc -Ilsns.p -I. -I.. -Iinclude -I../include -Ilibblkid -I../libblkid -I../libblkid/src -Ilibsmartcols -I../libsmartcols -I../libsmartcols/src -Ilibmount -I../libmount -I../libmount/src -Ilibfdisk -I../libfdisk -I../libfdisk/src -I../libuuid/src -Isys-utils -I../sys-utils -flto=auto -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -D_GNU_SOURCE -include config.h -fPIE -MD -MQ lsns.p/sys-utils_lsns.c.o -MF lsns.p/sys-utils_lsns.c.o.d -o lsns.p/sys-utils_lsns.c.o -c ../sys-utils/lsns.c
../sys-utils/lsns.c: In function ‘add_namespace_for_nsfd’:
../sys-utils/lsns.c:710:32: error: ‘NS_GET_NSTYPE’ undeclared (first use in this function)
  710 |         clone_type = ioctl(fd, NS_GET_NSTYPE);
      |                                ^~~~~~~~~~~~~
../sys-utils/lsns.c:710:32: note: each undeclared identifier is reported only once for each function it appears in
../sys-utils/lsns.c:717:30: error: ‘NS_GET_USERNS’ undeclared (first use in this function); did you mean ‘F_GET_SEALS’?
  717 |         fd_owner = ioctl(fd, NS_GET_USERNS);
      |                              ^~~~~~~~~~~~~
      |                              F_GET_SEALS
../sys-utils/lsns.c:725:31: error: ‘NS_GET_PARENT’ undeclared (first use in this function); did you mean ‘LSNS_TREE_PARENT’?
  725 |         fd_parent = ioctl(fd, NS_GET_PARENT);
      |                               ^~~~~~~~~~~~~
      |                               LSNS_TREE_PARENT
../sys-utils/lsns.c:734:19: error: ‘NS_GET_OWNER_UID’ undeclared (first use in this function)
  734 |         ioctl(fd, NS_GET_OWNER_UID, &ns->uid_fallback);
      |                   ^~~~~~~~~~~~~~~~
../sys-utils/lsns.c: In function ‘interpolate_missing_namespaces’:
../sys-utils/lsns.c:764:33: error: ‘NS_GET_PARENT’ undeclared (first use in this function); did you mean ‘LSNS_TREE_PARENT’?
  764 |                 [RELA_PARENT] = NS_GET_PARENT,
      |                                 ^~~~~~~~~~~~~
      |                                 LSNS_TREE_PARENT
../sys-utils/lsns.c:765:32: error: ‘NS_GET_USERNS’ undeclared (first use in this function); did you mean ‘F_GET_SEALS’?
  765 |                 [RELA_OWNER] = NS_GET_USERNS
      |                                ^~~~~~~~~~~~~
      |                                F_GET_SEALS

[karelzak]

Fixed. I have also added ./tools/compare-buildsys.sh to compare config.h from both build-systems. It's obvious that our meson configuration will require a lot of love in the next releases ;-)

[t-8ch]

Thanks.
One point for that would be to validate that the version listed in meson.build is synchronized with autotools.
(Currently it's out of date)

[karelzak]

Yes, and also list of header files could be shared and maybe more things, meson also does not care about version-info for shared libs, etc.