quotacheck,quotaon: Suggest using quota feature for ext4

Ext4 supports quota using internal quota files for quite some time.
Suggest using this quota feature instead of external quota files if the
kernel is new enough since external quota files on ext4 will be
deprecated.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 27 insertions, 0 deletions

diff --git a/quotasys.c b/quotasys.c
index d8c0e48..885fb1f 100644
--- a/quotasys.c
+++ b/quotasys.c
@@ -24,6 +24,7 @@
 #include <sys/stat.h>
 #include <sys/vfs.h>
 #include <stdint.h>
+#include <sys/utsname.h>
 
 #include "pot.h"
 #include "bylabel.h"
@@ -1597,3 +1598,29 @@ void end_mounts_scan(void)
 	check_dirs = NULL;
 	check_dirs_cnt = 0;
 }
+
+/* Parse kernel version and return 1 if ext4 supports quota feature */
+int ext4_supports_quota_feature(void)
+{
+	struct utsname stats;
+	int v;
+	char *errch;
+
+	if (uname(&stats) < 0) {
+		errstr(_("Cannot get system info: %s\n"), strerror(errno));
+		return 0;
+	}
+	if (strcmp(stats.sysname, "Linux"))
+		return 0;
+	v = strtol(stats.release, &errch, 10);
+	if (v < 4)
+		return 0;
+	if (v > 4)
+		return 1;
+	if (*errch != '.')
+		return 0;
+	v = strtol(errch + 1, &errch, 10);
+	if (*errch != '.' || v < 9)
+		return 0;
+	return 1;
+}