cgroup-util: modernize cg_get_keyed_attribute()

- assert on supplied keys being unique
- Reject duplicate attributes with -EBADMSG
- Rename 'ret_values' to just 'values', given we don't
  allocate the array
- Remove now unused cg_get_keyed_attribute_graceful()

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 21e8811e8d3c439b051cf6fc67ac244b92a2779f..d8e94c3ed9d0bf2826924b4db8c6ab471d04147f 100644 (file)
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -1777,56 +1777,61 @@ int cg_get_owner(const char *path, uid_t *ret_uid) {
         return 0;
 }
 
-int cg_get_keyed_attribute_full(
+int cg_get_keyed_attribute(
                 const char *controller,
                 const char *path,
                 const char *attribute,
-                char **keys,
-                char **ret_values,
-                CGroupKeyMode mode) {
+                char * const *keys,
+                char **values) {
 
         _cleanup_free_ char *filename = NULL, *contents = NULL;
-        const char *p;
-        size_t n, i, n_done = 0;
-        char **v;
+        size_t n;
         int r;
 
+        assert(path);
+        assert(attribute);
+
         /* Reads one or more fields of a cgroup v2 keyed attribute file. The 'keys' parameter should be an strv with
-         * all keys to retrieve. The 'ret_values' parameter should be passed as string size with the same number of
+         * all keys to retrieve. The 'values' parameter should be passed as string size with the same number of
          * entries as 'keys'. On success each entry will be set to the value of the matching key.
          *
-         * If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. If mode
-         * is set to GG_KEY_MODE_GRACEFUL we ignore missing keys and return those that were parsed successfully. */
+         * If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. */
 
         r = cg_get_path(controller, path, attribute, &filename);
         if (r < 0)
                 return r;
 
-        r = read_full_file(filename, &contents, NULL);
+        r = read_full_file(filename, &contents, /* ret_size = */ NULL);
         if (r < 0)
                 return r;
 
         n = strv_length(keys);
         if (n == 0) /* No keys to retrieve? That's easy, we are done then */
                 return 0;
+        assert(strv_is_uniq(keys));
 
         /* Let's build this up in a temporary array for now in order not to clobber the return parameter on failure */
-        v = newa0(char*, n);
+        char **v = newa0(char*, n);
+        size_t n_done = 0;
 
-        for (p = contents; *p;) {
-                const char *w = NULL;
+        for (const char *p = contents; *p;) {
+                const char *w;
+                size_t i;
 
-                for (i = 0; i < n; i++)
-                        if (!v[i]) {
-                                w = first_word(p, keys[i]);
-                                if (w)
-                                        break;
-                        }
+                for (i = 0; i < n; i++) {
+                        w = first_word(p, keys[i]);
+                        if (w)
+                                break;
+                }
 
                 if (w) {
-                        size_t l;
+                        if (v[i]) { /* duplicate entry? */
+                                r = -EBADMSG;
+                                goto fail;
+                        }
+
+                        size_t l = strcspn(w, NEWLINE);
 
-                        l = strcspn(w, NEWLINE);
                         v[i] = strndup(w, l);
                         if (!v[i]) {
                                 r = -ENOMEM;
@@ -1835,7 +1840,7 @@ int cg_get_keyed_attribute_full(
 
                         n_done++;
                         if (n_done >= n)
-                                goto done;
+                                break;
 
                         p = w + l;
                 } else
@@ -1844,21 +1849,17 @@ int cg_get_keyed_attribute_full(
                 p += strspn(p, NEWLINE);
         }
 
-        if (mode & CG_KEY_MODE_GRACEFUL)
-                goto done;
+        if (n_done < n) {
+                r = -ENXIO;
+                goto fail;
+        }
 
-        r = -ENXIO;
+        memcpy(values, v, sizeof(char*) * n);
+        return 0;
 
 fail:
         free_many_charp(v, n);
         return r;
-
-done:
-        memcpy(ret_values, v, sizeof(char*) * n);
-        if (mode & CG_KEY_MODE_GRACEFUL)
-                return n_done;
-
-        return 0;
 }
 
 int cg_mask_to_string(CGroupMask mask, char **ret) {

diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
index 5af7643b6f0c02d4173857944b8007712550c440..1d67174b43c20233e7fd11841cfb7a3644af85e1 100644 (file)
--- a/src/basic/cgroup-util.h
+++ b/src/basic/cgroup-util.h
@@ -226,31 +226,9 @@ int cg_is_delegated_fd(int fd);
 
 int cg_has_coredump_receive(const char *path);
 
-typedef enum {
-        CG_KEY_MODE_GRACEFUL = 1 << 0,
-} CGroupKeyMode;
-
 int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value);
 int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret);
-int cg_get_keyed_attribute_full(const char *controller, const char *path, const char *attribute, char **keys, char **values, CGroupKeyMode mode);
-
-static inline int cg_get_keyed_attribute(
-                const char *controller,
-                const char *path,
-                const char *attribute,
-                char **keys,
-                char **ret_values) {
-        return cg_get_keyed_attribute_full(controller, path, attribute, keys, ret_values, 0);
-}
-
-static inline int cg_get_keyed_attribute_graceful(
-                const char *controller,
-                const char *path,
-                const char *attribute,
-                char **keys,
-                char **ret_values) {
-        return cg_get_keyed_attribute_full(controller, path, attribute, keys, ret_values, CG_KEY_MODE_GRACEFUL);
-}
+int cg_get_keyed_attribute(const char *controller, const char *path, const char *attribute, char * const *keys, char **values);
 
 int cg_get_attribute_as_uint64(const char *controller, const char *path, const char *attribute, uint64_t *ret);
 

diff --git a/src/test/test-cgroup-util.c b/src/test/test-cgroup-util.c
index 32505f8293257e4127f00249664e8d9bbc8d0ce7..5bd3427ab4a40d8f66e5a1ecf7c7c932add16511 100644 (file)
--- a/src/test/test-cgroup-util.c
+++ b/src/test/test-cgroup-util.c
@@ -426,49 +426,22 @@ TEST(cg_get_keyed_attribute) {
         }
 
         assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat", STRV_MAKE("no_such_attr"), &val) == -ENXIO);
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat", STRV_MAKE("no_such_attr"), &val) == 0);
         ASSERT_NULL(val);
 
         assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec"), &val) == 0);
         val = mfree(val);
 
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec"), &val) == 1);
-        log_info("cpu /init.scope cpu.stat [usage_usec] → \"%s\"", val);
-
         assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec", "no_such_attr"), vals3) == -ENXIO);
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec", "no_such_attr"), vals3) == 1);
-        assert_se(vals3[0] && !vals3[1]);
-        free(vals3[0]);
-
-        assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec", "usage_usec"), vals3) == -ENXIO);
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat", STRV_MAKE("usage_usec", "usage_usec"), vals3) == 1);
-        assert_se(vals3[0] && !vals3[1]);
-        free(vals3[0]);
 
         assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat",
                                          STRV_MAKE("usage_usec", "user_usec", "system_usec"), vals3) == 0);
         for (size_t i = 0; i < 3; i++)
                 free(vals3[i]);
 
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat",
-                                         STRV_MAKE("usage_usec", "user_usec", "system_usec"), vals3) == 3);
-        log_info("cpu /init.scope cpu.stat [usage_usec user_usec system_usec] → \"%s\", \"%s\", \"%s\"",
-                 vals3[0], vals3[1], vals3[2]);
-
         assert_se(cg_get_keyed_attribute("cpu", "/init.scope", "cpu.stat",
                                          STRV_MAKE("system_usec", "user_usec", "usage_usec"), vals3a) == 0);
         for (size_t i = 0; i < 3; i++)
                 free(vals3a[i]);
-
-        assert_se(cg_get_keyed_attribute_graceful("cpu", "/init.scope", "cpu.stat",
-                                         STRV_MAKE("system_usec", "user_usec", "usage_usec"), vals3a) == 3);
-        log_info("cpu /init.scope cpu.stat [system_usec user_usec usage_usec] → \"%s\", \"%s\", \"%s\"",
-                 vals3a[0], vals3a[1], vals3a[2]);
-
-        for (size_t i = 0; i < 3; i++) {
-                free(vals3[i]);
-                free(vals3a[i]);
-        }
 }
 
 TEST(bfq_weight_conversion) {