[LTP] [PATCH v3 1/2] API/cgroup: Expose memory_recursiveprot V2 mount opt

[Richard Palethorpe]

This changes the effect of trunk nodes' memory.low and memory.min on
their leaf nodes. So we need to change the expectations of some tests.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
Suggested-by: Michal Koutný <mkoutny@suse.com>
---
 include/tst_cgroup.h |  3 +++
 lib/tst_cgroup.c     | 13 ++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/tst_cgroup.h b/include/tst_cgroup.h
index d32d62399..b822798e0 100644
--- a/include/tst_cgroup.h
+++ b/include/tst_cgroup.h
@@ -215,4 +215,7 @@ int safe_cg_occursin(const char *file, const int lineno,
 			 const char *const file_name,
 			 const char *const needle);
 
+int tst_cg_memory_recursiveprot(void)
+	__attribute__ ((warn_unused_result));
+
 #endif /* TST_CGROUP_H */
diff --git a/lib/tst_cgroup.c b/lib/tst_cgroup.c
index dc090b70a..01fa55e5b 100644
--- a/lib/tst_cgroup.c
+++ b/lib/tst_cgroup.c
@@ -76,6 +76,8 @@ struct cgroup_root {
 	int we_mounted_it:1;
 	/* cpuset is in compatability mode */
 	int no_cpuset_prefix:1;
+	/* V2 is mounted with memory_recursive_prot */
+	int memory_recursiveprot:1;
 };
 
 /* Controller sub-systems */
@@ -368,7 +370,7 @@ static void cgroup_root_scan(const char *const mnt_type,
 	const struct cgroup_ctrl *const_ctrl;
 	struct cgroup_ctrl *ctrl;
 	uint32_t ctrl_field = 0;
-	int no_prefix = 0;
+	int no_prefix = 0, memory_recursiveprot = 0;
 	char buf[BUFSIZ];
 	char *tok;
 	const int mnt_dfd = SAFE_OPEN(mnt_dir, O_PATH | O_DIRECTORY);
@@ -376,6 +378,9 @@ static void cgroup_root_scan(const char *const mnt_type,
 	if (!strcmp(mnt_type, "cgroup"))
 		goto v1;
 
+	for (tok = strtok(mnt_opts, ","); tok; tok = strtok(NULL, ","))
+		memory_recursiveprot |= !strcmp("memory_recursiveprot", tok);
+
 	SAFE_FILE_READAT(mnt_dfd, "cgroup.controllers", buf, sizeof(buf));
 
 	for (tok = strtok(buf, " "); tok; tok = strtok(NULL, " ")) {
@@ -433,6 +438,7 @@ backref:
 	root->mnt_dir.dir_fd = mnt_dfd;
 	root->ctrl_field = ctrl_field;
 	root->no_cpuset_prefix = no_prefix;
+	root->memory_recursiveprot = memory_recursiveprot;
 
 	for_each_ctrl(ctrl) {
 		if (has_ctrl(root->ctrl_field, ctrl))
@@ -1212,3 +1218,8 @@ int safe_cg_occursin(const char *const file, const int lineno,
 
 	return !!strstr(buf, needle);
 }
+
+int tst_cg_memory_recursiveprot(void)
+{
+	return roots[0].memory_recursiveprot;
+}
-- 
2.34.1