commit 75720bff62a84896e9a0654afc7cf9408cf89a38
Author: Filipe Brandenburger <filbranden@google.com>
Date:   Sun Jul 15 22:43:35 2018 -0700

    build-sys: Detect whether struct statx is defined in sys/stat.h
    
    Starting with glibc 2.27.9000-36.fc29, include file sys/stat.h will have a
    definition for struct statx, in which case include file linux/stat.h should be
    avoided, in order to prevent a duplicate definition.
    
        In file included from ../src/basic/missing.h:18,
                         from ../src/basic/util.h:28,
                         from ../src/basic/hashmap.h:10,
                         from ../src/shared/bus-util.h:12,
                         from ../src/libsystemd/sd-bus/bus-creds.c:11:
        /usr/include/linux/stat.h:99:8: error: redefinition of ‘struct statx’
         struct statx {
                ^~~~~
        In file included from /usr/include/sys/stat.h:446,
                         from ../src/basic/util.h:19,
                         from ../src/basic/hashmap.h:10,
                         from ../src/shared/bus-util.h:12,
                         from ../src/libsystemd/sd-bus/bus-creds.c:11:
        /usr/include/bits/statx.h:36:8: note: originally defined here
         struct statx
                ^~~~~
    
    Extend our meson.build to look for struct statx when only sys/stat.h is
    included and, in that case, do not include linux/stat.h anymore.
    
    Tested that systemd builds correctly when using a glibc version that includes a
    definition for struct statx.
    
    glibc Fedora RPM update:
    https://src.fedoraproject.org/rpms/glibc/c/28cb5d31fc1e5887912283c889689c47076278ae
    
    glibc upstream commit:
    https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=fd70af45528d59a00eb3190ef6706cb299488fcd

diff --git a/meson.build b/meson.build
index dd904c714..68423bdfa 100644
--- a/meson.build
+++ b/meson.build
@@ -425,6 +425,7 @@ decl_headers = '''
 #include <sys/stat.h>
 '''
 # FIXME: key_serial_t is only defined in keyutils.h, this is bound to fail
+# FIXME: these should use -D_GNU_SOURCE, since that is defined at build time
 
 foreach decl : ['char16_t',
                 'char32_t',
@@ -439,6 +440,10 @@ foreach decl : ['char16_t',
         conf.set10('HAVE_' + decl.underscorify().to_upper(), have)
 endforeach
 
+conf.set10('HAVE_STRUCT_STATX_IN_SYS_STAT_H', cc.sizeof('struct statx', prefix : '''
+#include <sys/stat.h>
+''', args : '-D_GNU_SOURCE') > 0)
+
 foreach decl : [['IFLA_INET6_ADDR_GEN_MODE',         'linux/if_link.h'],
                 ['IN6_ADDR_GEN_MODE_STABLE_PRIVACY', 'linux/if_link.h'],
                 ['IFLA_VRF_TABLE',                   'linux/if_link.h'],
diff --git a/src/basic/missing.h b/src/basic/missing.h
index 71a07d057..14ad3d491 100644
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -15,7 +15,6 @@
 #include <linux/neighbour.h>
 #include <linux/oom.h>
 #include <linux/rtnetlink.h>
-#include <linux/stat.h>
 #include <net/ethernet.h>
 #include <stdlib.h>
 #include <sys/resource.h>
@@ -25,6 +24,10 @@
 #include <uchar.h>
 #include <unistd.h>
 
+#if !HAVE_STRUCT_STATX_IN_SYS_STAT_H
+#include <linux/stat.h>
+#endif
+
 #if HAVE_AUDIT
 #include <libaudit.h>
 #endif
diff --git a/src/basic/xattr-util.c b/src/basic/xattr-util.c
index c5c55ea84..0ee097983 100644
--- a/src/basic/xattr-util.c
+++ b/src/basic/xattr-util.c
@@ -2,7 +2,6 @@
 
 #include <errno.h>
 #include <fcntl.h>
-#include <linux/stat.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
commit 9c869d08d82c73f62ab3527567858ce4b0cf1257
Author: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date:   Wed Jul 18 17:26:17 2018 +0200

    meson: unify linux/stat.h check with other checks and use _GNU_SOURCE
    
    Using _GNU_SOURCE is better because that's how we include the headers in the
    actual build, and some headers define different stuff when it is defined.
    sys/stat.h for example defines 'struct statx' conditionally.

diff --git a/meson.build b/meson.build
index 68423bdfa..99035d230 100644
--- a/meson.build
+++ b/meson.build
@@ -421,11 +421,9 @@ decl_headers = '''
 #include <uchar.h>
 #include <linux/ethtool.h>
 #include <linux/fib_rules.h>
-#include <linux/stat.h>
 #include <sys/stat.h>
 '''
 # FIXME: key_serial_t is only defined in keyutils.h, this is bound to fail
-# FIXME: these should use -D_GNU_SOURCE, since that is defined at build time
 
 foreach decl : ['char16_t',
                 'char32_t',
@@ -436,13 +434,23 @@ foreach decl : ['char16_t',
                ]
 
         # We get -1 if the size cannot be determined
-        have = cc.sizeof(decl, prefix : decl_headers) > 0
+        have = cc.sizeof(decl, prefix : decl_headers, args : '-D_GNU_SOURCE') > 0
+
+        if decl == 'struct statx'
+                if have
+                        want_linux_stat_h = false
+                else
+                        have = cc.sizeof(decl,
+                                         prefix : decl_headers + '#include <linux/stat.h>',
+                                         args : '-D_GNU_SOURCE') > 0
+                        want_linux_stat_h = have
+                endif
+        endif
+
         conf.set10('HAVE_' + decl.underscorify().to_upper(), have)
 endforeach
 
-conf.set10('HAVE_STRUCT_STATX_IN_SYS_STAT_H', cc.sizeof('struct statx', prefix : '''
-#include <sys/stat.h>
-''', args : '-D_GNU_SOURCE') > 0)
+conf.set10('WANT_LINUX_STAT_H', want_linux_stat_h)
 
 foreach decl : [['IFLA_INET6_ADDR_GEN_MODE',         'linux/if_link.h'],
                 ['IN6_ADDR_GEN_MODE_STABLE_PRIVACY', 'linux/if_link.h'],
diff --git a/src/basic/missing.h b/src/basic/missing.h
index 14ad3d491..9044683b1 100644
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -24,7 +24,7 @@
 #include <uchar.h>
 #include <unistd.h>
 
-#if !HAVE_STRUCT_STATX_IN_SYS_STAT_H
+#if WANT_LINUX_STAT_H
 #include <linux/stat.h>
 #endif