e2fsck: add portability fallback in case getpwuid_r is not present

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

configure

@@ -10893,7 +10893,7 @@ if test "$ac_res" != no; then :
 fi
 
 fi
-for ac_func in  	__secure_getenv 	backtrace 	blkid_probe_get_topology 	chflags 	fallocate 	fallocate64 	fchown 	fdatasync 	fstat64 	ftruncate64 	getdtablesize 	getmntinfo 	getrlimit 	getrusage 	jrand48 	llseek 	lseek64 	mallinfo 	mbstowcs 	memalign 	mmap 	msync 	nanosleep 	open64 	pathconf 	posix_fadvise 	posix_memalign 	prctl 	quotactl 	setresgid 	setresuid 	srandom 	strcasecmp 	strdup 	strnlen 	strptime 	strtoull 	sync_file_range 	sysconf 	usleep 	utime 	valloc
+for ac_func in  	__secure_getenv 	backtrace 	blkid_probe_get_topology 	chflags 	fallocate 	fallocate64 	fchown 	fdatasync 	fstat64 	ftruncate64 	getdtablesize 	getmntinfo 	getpwuid_r 	getrlimit 	getrusage 	jrand48 	llseek 	lseek64 	mallinfo 	mbstowcs 	memalign 	mmap 	msync 	nanosleep 	open64 	pathconf 	posix_fadvise 	posix_memalign 	prctl 	quotactl 	setresgid 	setresuid 	srandom 	strcasecmp 	strdup 	strnlen 	strptime 	strtoull 	sync_file_range 	sysconf 	usleep 	utime 	valloc
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"

configure.in

@@ -968,6 +968,7 @@ AC_CHECK_FUNCS(m4_flatten([
 	ftruncate64
 	getdtablesize
 	getmntinfo
+	getpwuid_r
 	getrlimit
 	getrusage
 	jrand48

e2fsck/logfile.c

@@ -126,7 +126,11 @@ static void expand_percent_expression(e2fsck_t ctx, char ch,
 		strcpy(buf, "tytso");
 		break;
 #else
+#ifdef HAVE_GETPWUID_R
 		getpwuid_r(getuid(), &pw_struct, buf, sizeof(buf), &pw);
+#else
+		pw = getpwuid(getuid());
+#endif
 		if (pw)
 			append_string(s, pw->pw_name, 0);
 		return;

lib/config.h.in

@@ -145,6 +145,9 @@
 /* Define to 1 if you have the `getpagesize' function. */
 #undef HAVE_GETPAGESIZE
 
+/* Define to 1 if you have the `getpwuid_r' function. */
+#undef HAVE_GETPWUID_R
+
 /* Define to 1 if you have the `getrlimit' function. */
 #undef HAVE_GETRLIMIT