Add a function - cgroup_convert_cgroup() - that can convert from
one cgroup version to another. This function will be the building
block for the libcgroup abstraction layer.
Signed-off-by: Tom Hromatka <tom.hroma...@oracle.com>
---
src/abstraction-common.c | 103 +++++++++++++++++++++++++++++++++++++++
src/abstraction-common.h | 17 +++++++
src/libcgroup-internal.h | 1 +
src/libcgroup.map | 4 ++
4 files changed, 125 insertions(+)
diff --git a/src/abstraction-common.c b/src/abstraction-common.c
index df5fa1b3a452..e0e3984006b7 100644
--- a/src/abstraction-common.c
+++ b/src/abstraction-common.c
@@ -29,6 +29,7 @@
#include <unistd.h>
#include "abstraction-common.h"
+#include "abstraction-map.h"
int cgroup_strtol(const char * const in_str, int base,
long int * const out_value)
@@ -108,3 +109,105 @@ out:
return ret;
}
+
+static int convert_setting(struct cgroup_controller * const out_cgc,
+ const struct control_value * const in_ctrl_val)
+{
+ const struct cgroup_abstraction_map *convert_tbl;
+ int tbl_sz = 0;
+ int ret = ECGINVAL;
+ int i;
+
+ switch (out_cgc->version) {
+ case CGROUP_V1:
+ convert_tbl = cgroup_v2_to_v1_map;
+ tbl_sz = cgroup_v2_to_v1_map_sz;
+ break;
+ case CGROUP_V2:
+ convert_tbl = cgroup_v1_to_v2_map;
+ tbl_sz = cgroup_v1_to_v2_map_sz;
+ break;
+ default:
+ ret = ECGFAIL;
+ goto out;
+ }
+
+ for (i = 0; i < tbl_sz; i++) {
+ if (strcmp(convert_tbl[i].in_setting, in_ctrl_val->name) == 0) {
+ ret = convert_tbl[i].cgroup_convert(out_cgc,
+ in_ctrl_val->value,
+ convert_tbl[i].out_setting,
+ convert_tbl[i].in_dflt,
+ convert_tbl[i].out_dflt);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static int convert_controller(struct cgroup_controller * const out_cgc,
+ const struct cgroup_controller * const in_cgc)
+{
+ int ret;
+ int i;
+
+
+ if (in_cgc->version == out_cgc->version) {
+ ret = cgroup_copy_controller_values(out_cgc, in_cgc);
+ /* regardless of success/failure, there's nothing more to do */
+ goto out;
+ }
+
+ for (i = 0; i < in_cgc->index; i++) {
+ ret = convert_setting(out_cgc, in_cgc->values[i]);
+ if (ret)
+ goto out;
+ }
+
+out:
+ return ret;
+}
+
+int cgroup_convert_cgroup(struct cgroup * const out_cgroup,
+ enum cg_version_t out_version,
+ const struct cgroup * const in_cgroup,
+ enum cg_version_t in_version)
+{
+ struct cgroup_controller *cgc;
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < in_cgroup->index; i++) {
+ cgc = cgroup_add_controller(out_cgroup,
+ in_cgroup->controller[i]->name);
+ if (cgc == NULL) {
+ ret = ECGFAIL;
+ goto out;
+ }
+
+ /* the user has overridden the version */
+ if (in_version == CGROUP_V1 || in_version == CGROUP_V2) {
+ in_cgroup->controller[i]->version = in_version;
+ }
+
+ cgc->version = out_version;
+
+ if (cgc->version == CGROUP_UNK ||
+ cgc->version == CGROUP_DISK) {
+ ret = cgroup_get_controller_version(cgc->name,
+ &cgc->version);
+ if (ret)
+ goto out;
+ }
+
+ ret = convert_controller(cgc, in_cgroup->controller[i]);
+ if (ret)
+ goto out;
+ }
+
+out:
+ return ret;
+}
diff --git a/src/abstraction-common.h b/src/abstraction-common.h
index 02f7b9ff9541..69a28538e091 100644
--- a/src/abstraction-common.h
+++ b/src/abstraction-common.h
@@ -57,6 +57,23 @@ int cgroup_convert_int(struct cgroup_controller * const
dst_cgc,
const char * const out_setting,
void *in_dflt, void *out_dflt);
+/*
+ * Convert from one cgroup version to another version
+ *
+ * @param out_cgroup Destination cgroup
+ * @param out_version Destination cgroup version
+ * @param in_cgroup Source cgroup
+ * @param in_version Source cgroup version, only used if set to v1 or v2
+ *
+ * @return 0 on success
+ * ECGFAIL conversion failed
+ * ECGCONTROLLERNOTEQUAL incorrect controller version provided
+ */
+int cgroup_convert_cgroup(struct cgroup * const out_cgroup,
+ enum cg_version_t out_version,
+ const struct cgroup * const in_cgroup,
+ enum cg_version_t in_version);
+
#ifdef __cplusplus
} /* extern "C" */
#endif
diff --git a/src/libcgroup-internal.h b/src/libcgroup-internal.h
index 34c5be703920..6d9de03a00bc 100644
--- a/src/libcgroup-internal.h
+++ b/src/libcgroup-internal.h
@@ -89,6 +89,7 @@ enum cg_version_t {
CGROUP_UNK = 0,
CGROUP_V1,
CGROUP_V2,
+ CGROUP_DISK = 0xFF,
};
struct control_value {
diff --git a/src/libcgroup.map b/src/libcgroup.map
index 68098cd3accb..d99a2ce73c04 100644
--- a/src/libcgroup.map
+++ b/src/libcgroup.map
@@ -139,3 +139,7 @@ CGROUP_2.0 {
cg_mount_table_lock;
cgroup_get_controller_version;
} CGROUP_0.42;
+
+CGROUP_3.0 {
+ cgroup_convert_cgroup;
+} CGROUP_2.0;
--
2.25.1
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