[LTP] [PATCH v2 4/5] API/cgroup: Make tst_cgroup_group_mk sprintf like

[Richard Palethorpe]

Allows the name to be formatted which is trivial because we already
copy it into a buffer. Also this removes the init function which is
now just unnecessary verbiage.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
Suggested-by: Cyril Hrubis <chrubis@suse.cz>
---
 include/tst_cgroup.h |  5 +++--
 lib/tst_cgroup.c     | 29 ++++++++++++-----------------
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/include/tst_cgroup.h b/include/tst_cgroup.h
index 17adefd2b..d7a3433fa 100644
--- a/include/tst_cgroup.h
+++ b/include/tst_cgroup.h
@@ -126,8 +126,9 @@ void tst_cgroup_init(void);
 /* Create a descendant CGroup */
 struct tst_cgroup_group *
 tst_cgroup_group_mk(const struct tst_cgroup_group *const parent,
-		    const char *const group_name)
-		    __attribute__ ((nonnull, warn_unused_result));
+		    const char *const group_name_fmt, ...)
+	    __attribute__ ((nonnull, warn_unused_result, format (printf, 2, 3)));
+
 const char *
 tst_cgroup_group_name(const struct tst_cgroup_group *const cg)
 		      __attribute__ ((nonnull, warn_unused_result));
diff --git a/lib/tst_cgroup.c b/lib/tst_cgroup.c
index d9cd6aa8e..66f17575e 100644
--- a/lib/tst_cgroup.c
+++ b/lib/tst_cgroup.c
@@ -840,21 +840,6 @@ clear_data:
 	memset(roots, 0, sizeof(roots));
 }
 
-__attribute__((nonnull(1)))
-static void cgroup_group_init(struct tst_cgroup_group *const cg,
-			      const char *const group_name)
-{
-	memset(cg, 0, sizeof(*cg));
-
-	if (!group_name)
-		return;
-
-	if (strlen(group_name) > NAME_MAX)
-		tst_brk(TBROK, "Group name is too long");
-
-	strcpy(cg->group_name, group_name);
-}
-
 __attribute__((nonnull(2, 3)))
 static void cgroup_group_add_dir(const struct tst_cgroup_group *const parent,
 				 struct tst_cgroup_group *const cg,
@@ -886,14 +871,24 @@ static void cgroup_group_add_dir(const struct tst_cgroup_group *const parent,
 
 struct tst_cgroup_group *
 tst_cgroup_group_mk(const struct tst_cgroup_group *const parent,
-		    const char *const group_name)
+		    const char *const group_name_fmt, ...)
 {
 	struct tst_cgroup_group *cg;
 	struct cgroup_dir *const *dir;
 	struct cgroup_dir *new_dir;
+	va_list ap;
+	size_t name_len;
 
 	cg = SAFE_MALLOC(sizeof(*cg));
-	cgroup_group_init(cg, group_name);
+	memset(cg, 0, sizeof(*cg));
+
+	va_start(ap, group_name_fmt);
+	name_len = vsnprintf(cg->group_name, NAME_MAX,
+			     group_name_fmt, ap);
+	va_end(ap);
+
+	if (name_len >= NAME_MAX)
+		tst_brk(TBROK, "CGroup name is too long");
 
 	for_each_dir(parent, 0, dir) {
 		new_dir = SAFE_MALLOC(sizeof(*new_dir));
-- 
2.34.1