From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Wed, 25 Aug 2021 17:20:57 +0000 (+0200)
Subject: conf: port cgroup settings to new list type
X-Git-Tag: lxc-5.0.0~102^2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c9dbb8edf972182c8b046ea6161d5e48e914cd01;p=thirdparty%2Flxc.git

conf: port cgroup settings to new list type

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 54b298910..23aef495c 100644
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -2707,11 +2707,8 @@ __cgfsng_ops static bool cgfsng_setup_limits_legacy(struct cgroup_ops *ops,
 						    struct lxc_conf *conf,
 						    bool do_devices)
 {
-	__do_free struct lxc_list *sorted_cgroup_settings = NULL;
-	struct lxc_list *cgroup_settings = &conf->cgroup;
-	struct lxc_list *iterator, *next;
-	struct lxc_cgroup *cg;
-	bool ret = false;
+	struct list_head *cgroup_settings;
+	struct lxc_cgroup *cgroup;
 
 	if (!ops)
 		return ret_set_errno(false, ENOENT);
@@ -2720,7 +2717,7 @@ __cgfsng_ops static bool cgfsng_setup_limits_legacy(struct cgroup_ops *ops,
 		return ret_set_errno(false, EINVAL);
 
 	cgroup_settings = &conf->cgroup;
-	if (lxc_list_empty(cgroup_settings))
+	if (list_empty(cgroup_settings))
 		return true;
 
 	if (!ops->hierarchies)
@@ -2729,35 +2726,23 @@ __cgfsng_ops static bool cgfsng_setup_limits_legacy(struct cgroup_ops *ops,
 	if (pure_unified_layout(ops))
 		return log_warn_errno(true, EINVAL, "Ignoring legacy cgroup limits on pure cgroup2 system");
 
-	sorted_cgroup_settings = sort_cgroup_settings(cgroup_settings);
-	if (!sorted_cgroup_settings)
-		return false;
-
-	lxc_list_for_each(iterator, sorted_cgroup_settings) {
-		cg = iterator->elem;
-
-		if (do_devices == strnequal("devices", cg->subsystem, 7)) {
-			if (cg_legacy_set_data(ops, cg->subsystem, cg->value, strnequal("cpuset", cg->subsystem, 6))) {
+	sort_cgroup_settings(conf);
+	list_for_each_entry(cgroup, cgroup_settings, head) {
+		if (do_devices == strnequal("devices", cgroup->subsystem, 7)) {
+			if (cg_legacy_set_data(ops, cgroup->subsystem, cgroup->value, strnequal("cpuset", cgroup->subsystem, 6))) {
 				if (do_devices && (errno == EACCES || errno == EPERM)) {
-					SYSWARN("Failed to set \"%s\" to \"%s\"", cg->subsystem, cg->value);
+					SYSWARN("Failed to set \"%s\" to \"%s\"", cgroup->subsystem, cgroup->value);
 					continue;
 				}
-				SYSERROR("Failed to set \"%s\" to \"%s\"", cg->subsystem, cg->value);
-				goto out;
+				SYSERROR("Failed to set \"%s\" to \"%s\"", cgroup->subsystem, cgroup->value);
+				return false;
 			}
-			DEBUG("Set controller \"%s\" set to \"%s\"", cg->subsystem, cg->value);
+			DEBUG("Set controller \"%s\" set to \"%s\"", cgroup->subsystem, cgroup->value);
 		}
 	}
 
-	ret = true;
 	INFO("Limits for the legacy cgroup hierarchies have been setup");
-out:
-	lxc_list_for_each_safe(iterator, sorted_cgroup_settings, next) {
-		lxc_list_del(iterator);
-		free(iterator);
-	}
-
-	return ret;
+	return true;
 }
 
 /*
@@ -2793,9 +2778,10 @@ static int bpf_device_cgroup_prepare(struct cgroup_ops *ops,
 __cgfsng_ops static bool cgfsng_setup_limits(struct cgroup_ops *ops,
 					     struct lxc_handler *handler)
 {
-	struct lxc_list *cgroup_settings, *iterator;
+	struct list_head *cgroup_settings;
 	struct hierarchy *h;
 	struct lxc_conf *conf;
+	struct lxc_cgroup *cgroup;
 
 	if (!ops)
 		return ret_set_errno(false, ENOENT);
@@ -2811,7 +2797,7 @@ __cgfsng_ops static bool cgfsng_setup_limits(struct cgroup_ops *ops,
 	conf = handler->conf;
 
 	cgroup_settings = &conf->cgroup2;
-	if (lxc_list_empty(cgroup_settings))
+	if (list_empty(cgroup_settings))
 		return true;
 
 	if (!pure_unified_layout(ops))
@@ -2821,18 +2807,17 @@ __cgfsng_ops static bool cgfsng_setup_limits(struct cgroup_ops *ops,
 		return false;
 	h = ops->unified;
 
-	lxc_list_for_each (iterator, cgroup_settings) {
-		struct lxc_cgroup *cg = iterator->elem;
+	list_for_each_entry(cgroup, cgroup_settings, head) {
 		int ret;
 
-		if (strnequal("devices", cg->subsystem, 7))
-			ret = bpf_device_cgroup_prepare(ops, conf, cg->subsystem, cg->value);
+		if (strnequal("devices", cgroup->subsystem, 7))
+			ret = bpf_device_cgroup_prepare(ops, conf, cgroup->subsystem, cgroup->value);
 		else
-			ret = lxc_write_openat(h->path_lim, cg->subsystem, cg->value, strlen(cg->value));
+			ret = lxc_write_openat(h->path_lim, cgroup->subsystem, cgroup->value, strlen(cgroup->value));
 		if (ret < 0)
-			return log_error_errno(false, errno, "Failed to set \"%s\" to \"%s\"", cg->subsystem, cg->value);
+			return log_error_errno(false, errno, "Failed to set \"%s\" to \"%s\"", cgroup->subsystem, cgroup->value);
 
-		TRACE("Set \"%s\" to \"%s\"", cg->subsystem, cg->value);
+		TRACE("Set \"%s\" to \"%s\"", cgroup->subsystem, cgroup->value);
 	}
 
 	return log_info(true, "Limits for the unified cgroup hierarchy have been setup");
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index d048874ef..f0c6c74be 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3379,8 +3379,8 @@ struct lxc_conf *lxc_conf_init(void)
 	new->rootfs.fd_path_pin = -EBADF;
 	new->rootfs.dfd_idmapped = -EBADF;
 	new->logfd = -1;
-	lxc_list_init(&new->cgroup);
-	lxc_list_init(&new->cgroup2);
+	INIT_LIST_HEAD(&new->cgroup);
+	INIT_LIST_HEAD(&new->cgroup2);
 	/* Block ("allowlist") all devices by default. */
 	new->bpf_devices.list_type = LXC_BPF_DEVICE_CGROUP_ALLOWLIST;
 	INIT_LIST_HEAD(&(new->bpf_devices).devices);
@@ -4538,11 +4538,12 @@ int lxc_clear_namespace(struct lxc_conf *c)
 
 int lxc_clear_cgroups(struct lxc_conf *c, const char *key, int version)
 {
-	char *global_token, *namespaced_token;
-	size_t namespaced_token_len;
-	struct lxc_list *it, *next, *list;
 	const char *k = key;
 	bool all = false;
+	char *global_token, *namespaced_token;
+	size_t namespaced_token_len;
+	struct list_head *list;
+	struct lxc_cgroup *cgroup, *ncgroup;
 
 	if (version == CGROUP2_SUPER_MAGIC) {
 		global_token		= "lxc.cgroup2";
@@ -4565,21 +4566,18 @@ int lxc_clear_cgroups(struct lxc_conf *c, const char *key, int version)
 	else
 		return ret_errno(EINVAL);
 
-	lxc_list_for_each_safe(it, list, next) {
-		struct lxc_cgroup *cg = it->elem;
-
-		if (!all && !strequal(cg->subsystem, k))
+	list_for_each_entry_safe(cgroup, ncgroup, list, head) {
+		if (!all && !strequal(cgroup->subsystem, k))
 			continue;
 
-		lxc_list_del(it);
-		free(cg->subsystem);
-		free(cg->value);
-		free(cg);
-		free(it);
+		list_del(&cgroup->head);
+		free(cgroup->subsystem);
+		free(cgroup->value);
+		free(cgroup);
 	}
 
 	if (all)
-		lxc_list_init(list);
+		INIT_LIST_HEAD(list);
 
 	return 0;
 }
@@ -5817,54 +5815,25 @@ void suggest_default_idmap(void)
 	ERROR("lxc.idmap = g 0 %u %u", gid, grange);
 }
 
-static void free_cgroup_settings(struct lxc_list *result)
-{
-	struct lxc_list *iterator, *next;
-
-	lxc_list_for_each_safe (iterator, result, next) {
-		lxc_list_del(iterator);
-		free_disarm(iterator);
-	}
-	free_disarm(result);
-}
-
 /* Return the list of cgroup_settings sorted according to the following rules
  * 1. Put memory.limit_in_bytes before memory.memsw.limit_in_bytes
  */
-struct lxc_list *sort_cgroup_settings(struct lxc_list *cgroup_settings)
+void sort_cgroup_settings(struct lxc_conf *conf)
 {
-	struct lxc_list *result;
-	struct lxc_cgroup *cg = NULL;
-	struct lxc_list *it = NULL, *item = NULL, *memsw_limit = NULL;
-
-	result = lxc_list_new();
-	if (!result)
-		return NULL;
-	lxc_list_init(result);
+	struct lxc_cgroup *cgroup, *memsw_limit, *ncgroup;
 
 	/* Iterate over the cgroup settings and copy them to the output list. */
-	lxc_list_for_each (it, cgroup_settings) {
-		item = zalloc(sizeof(*item));
-		if (!item) {
-			free_cgroup_settings(result);
-			return NULL;
-		}
-
-		item->elem = it->elem;
-		cg = it->elem;
-		if (strequal(cg->subsystem, "memory.memsw.limit_in_bytes")) {
+	list_for_each_entry_safe(cgroup, ncgroup, &conf->cgroup, head) {
+		if (strequal(cgroup->subsystem, "memory.memsw.limit_in_bytes")) {
 			/* Store the memsw_limit location */
-			memsw_limit = item;
-		} else if (strequal(cg->subsystem, "memory.limit_in_bytes") &&
-			   memsw_limit != NULL) {
-			/* lxc.cgroup.memory.memsw.limit_in_bytes is found
+			memsw_limit = cgroup;
+		} else if (memsw_limit && strequal(cgroup->subsystem, "memory.limit_in_bytes")) {
+			/*
+			 * lxc.cgroup.memory.memsw.limit_in_bytes is found
 			 * before lxc.cgroup.memory.limit_in_bytes, swap these
-			 * two items */
-			item->elem = memsw_limit->elem;
-			memsw_limit->elem = it->elem;
+			 * two items.
+			 */
+			list_swap(&memsw_limit->head, &cgroup->head);
 		}
-		lxc_list_add_tail(result, item);
 	}
-
-	return result;
 }
diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 00b4a5849..e8d776cdc 100644
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -78,6 +78,8 @@ struct lxc_cgroup {
 			bool relative;
 		};
 	};
+
+	struct list_head head;
 };
 
 static void free_lxc_cgroup(struct lxc_cgroup *ptr)
@@ -344,8 +346,8 @@ struct lxc_conf {
 	struct utsname *utsname;
 
 	struct {
-		struct lxc_list cgroup;
-		struct lxc_list cgroup2;
+		struct list_head cgroup;
+		struct list_head cgroup2;
 		struct bpf_devices bpf_devices;
 	};
 
@@ -557,7 +559,7 @@ __hidden extern int parse_mount_attrs(struct lxc_mount_options *opts, const char
 __hidden extern void tmp_proc_unmount(struct lxc_conf *lxc_conf);
 __hidden extern void suggest_default_idmap(void);
 __hidden extern FILE *make_anonymous_mount_file(struct lxc_list *mount, bool include_nesting_helpers);
-__hidden extern struct lxc_list *sort_cgroup_settings(struct lxc_list *cgroup_settings);
+__hidden extern void sort_cgroup_settings(struct lxc_conf *conf);
 __hidden extern int run_script(const char *name, const char *section, const char *script, ...);
 __hidden extern int run_script_argv(const char *name, unsigned int hook_version, const char *section,
 				    const char *script, const char *hookname, char **argsin);
diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 97b822b1a..513b917d9 100644
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -1858,8 +1858,7 @@ static int set_config_signal_stop(const char *key, const char *value,
 static int __set_config_cgroup_controller(const char *key, const char *value,
 					  struct lxc_conf *lxc_conf, int version)
 {
-	__do_free struct lxc_list *cglist = NULL;
-	call_cleaner(free_lxc_cgroup) struct lxc_cgroup *cgelem = NULL;
+	call_cleaner(free_lxc_cgroup) struct lxc_cgroup *new_cgroup = NULL;
 	const char *subkey, *token;
 	size_t token_len;
 
@@ -1883,31 +1882,25 @@ static int __set_config_cgroup_controller(const char *key, const char *value,
 	if (*subkey == '\0')
 		return ret_errno(EINVAL);
 
-	cglist = lxc_list_new();
-	if (!cglist)
+	new_cgroup = zalloc(sizeof(*new_cgroup));
+	if (!new_cgroup)
 		return ret_errno(ENOMEM);
 
-	cgelem = zalloc(sizeof(*cgelem));
-	if (!cgelem)
+	new_cgroup->subsystem = strdup(subkey);
+	if (!new_cgroup->subsystem)
 		return ret_errno(ENOMEM);
 
-	cgelem->subsystem = strdup(subkey);
-	if (!cgelem->subsystem)
+	new_cgroup->value = strdup(value);
+	if (!new_cgroup->value)
 		return ret_errno(ENOMEM);
 
-	cgelem->value = strdup(value);
-	if (!cgelem->value)
-		return ret_errno(ENOMEM);
-
-	cgelem->version = version;
-
-	lxc_list_add_elem(cglist, move_ptr(cgelem));
+	new_cgroup->version = version;
 
 	if (version == CGROUP2_SUPER_MAGIC)
-		lxc_list_add_tail(&lxc_conf->cgroup2, cglist);
+		list_add_tail(&new_cgroup->head, &lxc_conf->cgroup2);
 	else
-		lxc_list_add_tail(&lxc_conf->cgroup, cglist);
-	move_ptr(cglist);
+		list_add_tail(&new_cgroup->head, &lxc_conf->cgroup);
+	move_ptr(new_cgroup);
 
 	return 0;
 }
@@ -3842,12 +3835,13 @@ static int __get_config_cgroup_controller(const char *key, char *retv,
 					  int inlen, struct lxc_conf *c,
 					  int version)
 {
+	int fulllen = 0;
+	bool get_all = false;
 	int len;
 	size_t namespaced_token_len;
 	char *global_token, *namespaced_token;
-	struct lxc_list *it;
-	int fulllen = 0;
-	bool get_all = false;
+	struct list_head *list;
+	struct lxc_cgroup *cgroup;
 
 	if (!retv)
 		inlen = 0;
@@ -3858,10 +3852,12 @@ static int __get_config_cgroup_controller(const char *key, char *retv,
 		global_token = "lxc.cgroup2";
 		namespaced_token = "lxc.cgroup2.";
 		namespaced_token_len = STRLITERALLEN("lxc.cgroup2.");
+		list = &c->cgroup2;
 	} else if (version == CGROUP_SUPER_MAGIC) {
 		global_token = "lxc.cgroup";
 		namespaced_token = "lxc.cgroup.";
 		namespaced_token_len = STRLITERALLEN("lxc.cgroup.");
+		list = &c->cgroup;
 	} else {
 		return ret_errno(EINVAL);
 	}
@@ -3873,17 +3869,15 @@ static int __get_config_cgroup_controller(const char *key, char *retv,
 	else
 		return ret_errno(EINVAL);
 
-	lxc_list_for_each(it, &c->cgroup) {
-		struct lxc_cgroup *cg = it->elem;
-
+	list_for_each_entry(cgroup, list, head) {
 		if (get_all) {
-			if (version != cg->version)
+			if (version != cgroup->version)
 				continue;
 
 			strprint(retv, inlen, "%s.%s = %s\n", global_token,
-				 cg->subsystem, cg->value);
-		} else if (strequal(cg->subsystem, key)) {
-			strprint(retv, inlen, "%s\n", cg->value);
+				 cgroup->subsystem, cgroup->value);
+		} else if (strequal(cgroup->subsystem, key)) {
+			strprint(retv, inlen, "%s\n", cgroup->value);
 		}
 	}