tools/xenstore: switch quota management to be table based

Instead of having individual quota variables switch to a table based
approach like the generic accounting. Include all the related data in
the same table and add accessor functions.

This enables to use the command line --quota parameter for setting all
possible quota values, keeping the previous parameters for
compatibility.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>

tools/xenstore/xenstored_control.c

@@ -221,35 +221,6 @@ static int do_control_log(const void *ctx, struct connection *conn,
 	return 0;
 }
 
-struct quota {
-	const char *name;
-	int *quota;
-	const char *descr;
-};
-
-static const struct quota hard_quotas[] = {
-	{ "nodes", &quota_nb_entry_per_domain, "Nodes per domain" },
-	{ "watches", &quota_nb_watch_per_domain, "Watches per domain" },
-	{ "transactions", &quota_max_transaction, "Transactions per domain" },
-	{ "outstanding", &quota_req_outstanding,
-		"Outstanding requests per domain" },
-	{ "transaction-nodes", &quota_trans_nodes,
-		"Max. number of accessed nodes per transaction" },
-	{ "memory", &quota_memory_per_domain_hard,
-		"Total Xenstore memory per domain (error level)" },
-	{ "node-size", &quota_max_entry_size, "Max. size of a node" },
-	{ "path-max", &quota_max_path_len, "Max. length of a node path" },
-	{ "permissions", &quota_nb_perms_per_node,
-		"Max. number of permissions per node" },
-	{ NULL, NULL, NULL }
-};
-
-static const struct quota soft_quotas[] = {
-	{ "memory", &quota_memory_per_domain_soft,
-		"Total Xenstore memory per domain (warning level)" },
-	{ NULL, NULL, NULL }
-};
-
 static int quota_show_current(const void *ctx, struct connection *conn,
 			      const struct quota *quotas)
 {
@@ -260,9 +231,11 @@ static int quota_show_current(const void *ctx, struct connection *conn,
 	if (!resp)
 		return ENOMEM;
 
-	for (i = 0; quotas[i].quota; i++) {
+	for (i = 0; i < ACC_N; i++) {
+		if (!quotas[i].name)
+			continue;
 		resp = talloc_asprintf_append(resp, "%-17s: %8d %s\n",
-					      quotas[i].name, *quotas[i].quota,
+					      quotas[i].name, quotas[i].val,
 					      quotas[i].descr);
 		if (!resp)
 			return ENOMEM;
@@ -274,7 +247,7 @@ static int quota_show_current(const void *ctx, struct connection *conn,
 }
 
 static int quota_set(const void *ctx, struct connection *conn,
-		     char **vec, int num, const struct quota *quotas)
+		     char **vec, int num, struct quota *quotas)
 {
 	unsigned int i;
 	int val;
@@ -286,9 +259,9 @@ static int quota_set(const void *ctx, struct connection *conn,
 	if (val < 1)
 		return EINVAL;
 
-	for (i = 0; quotas[i].quota; i++) {
-		if (!strcmp(vec[0], quotas[i].name)) {
-			*quotas[i].quota = val;
+	for (i = 0; i < ACC_N; i++) {
+		if (quotas[i].name && !strcmp(vec[0], quotas[i].name)) {
+			quotas[i].val = val;
 			send_ack(conn, XS_CONTROL);
 			return 0;
 		}

tools/xenstore/xenstored_core.c

@@ -89,17 +89,6 @@ unsigned int trace_flags = TRACE_OBJ | TRACE_IO;
 
 static const char *sockmsg_string(enum xsd_sockmsg_type type);
 
-int quota_nb_entry_per_domain = 1000;
-int quota_nb_watch_per_domain = 128;
-int quota_max_entry_size = 2048; /* 2K */
-int quota_max_transaction = 10;
-int quota_nb_perms_per_node = 5;
-int quota_trans_nodes = 1024;
-int quota_max_path_len = XENSTORE_REL_PATH_MAX;
-int quota_req_outstanding = 20;
-int quota_memory_per_domain_soft = 2 * 1024 * 1024; /* 2 MB */
-int quota_memory_per_domain_hard = 2 * 1024 * 1024 + 512 * 1024; /* 2.5 MB */
-
 unsigned int timeout_watch_event_msec = 20000;
 
 void trace(const char *fmt, ...)
@@ -800,8 +789,7 @@ int write_node_raw(struct connection *conn, TDB_DATA *key, struct node *node,
 		+ node->datalen + node->childlen;
 
 	/* Call domain_max_chk() in any case in order to record max values. */
-	if (domain_max_chk(conn, ACC_NODESZ, data.dsize, quota_max_entry_size)
-	    && !no_quota_check) {
+	if (domain_max_chk(conn, ACC_NODESZ, data.dsize) && !no_quota_check) {
 		errno = ENOSPC;
 		return errno;
 	}
@@ -1191,8 +1179,7 @@ bool is_valid_nodename(const struct connection *conn, const char *node)
 	if (sscanf(node, "/local/domain/%5u/%n", &domid, &local_off) != 1)
 		local_off = 0;
 
-	if (domain_max_chk(conn, ACC_PATHLEN, strlen(node) - local_off,
-			   quota_max_path_len))
+	if (domain_max_chk(conn, ACC_PATHLEN, strlen(node) - local_off))
 		return false;
 
 	return valid_chars(node);
@@ -1504,7 +1491,7 @@ static struct node *create_node(struct connection *conn, const void *ctx,
 	for (i = node; i; i = i->parent) {
 		/* i->parent is set for each new node, so check quota. */
 		if (i->parent &&
-		    domain_nbentry(conn) >= quota_nb_entry_per_domain) {
+		    domain_nbentry(conn) >= hard_quotas[ACC_NODES].val) {
 			ret = ENOSPC;
 			goto err;
 		}
@@ -1786,7 +1773,7 @@ static int do_set_perms(const void *ctx, struct connection *conn,
 		return EINVAL;
 
 	perms.num--;
-	if (domain_max_chk(conn, ACC_NPERM, perms.num, quota_nb_perms_per_node))
+	if (domain_max_chk(conn, ACC_NPERM, perms.num))
 		return ENOSPC;
 
 	permstr = in->buffer + strlen(in->buffer) + 1;
@@ -2655,7 +2642,16 @@ static void usage(void)
 "                          memory: total used memory per domain for nodes,\n"
 "                                  transactions, watches and requests, above\n"
 "                                  which Xenstore will stop talking to domain\n"
+"                          nodes: number nodes owned by a domain\n"
+"                          node-permissions: number of access permissions per\n"
+"                                            node\n"
+"                          node-size: total size of a node (permissions +\n"
+"                                     children names + content)\n"
 "                          outstanding: number of outstanding requests\n"
+"                          path-length: length of a node path\n"
+"                          transactions: number of concurrent transactions\n"
+"                                        per domain\n"
+"                          watches: number of watches per domain"
 "  -q, --quota-soft <what>=<nb> set a soft quota <what> to the value <nb>,\n"
 "                          causing a warning to be issued via syslog() if the\n"
 "                          limit is violated, allowed quotas are:\n"
@@ -2720,7 +2716,12 @@ static unsigned int get_optval_uint(const char *arg)
 
 static bool what_matches(const char *arg, const char *what)
 {
-	unsigned int what_len = strlen(what);
+	unsigned int what_len;
+
+	if (!what)
+		return false;
+
+	what_len = strlen(what);
 
 	return !strncmp(arg, what, what_len) && arg[what_len] == '=';
 }
@@ -2728,7 +2729,7 @@ static bool what_matches(const char *arg, const char *what)
 static void set_timeout(const char *arg)
 {
 	const char *eq = strchr(arg, '=');
-	int val;
+	unsigned int val;
 
 	if (!eq)
 		barf("quotas must be specified via <what>=<seconds>\n");
@@ -2742,22 +2743,22 @@ static void set_timeout(const char *arg)
 static void set_quota(const char *arg, bool soft)
 {
 	const char *eq = strchr(arg, '=');
-	int val;
+	struct quota *q = soft ? soft_quotas : hard_quotas;
+	unsigned int val;
+	unsigned int i;
 
 	if (!eq)
 		barf("quotas must be specified via <what>=<nb>\n");
 	val = get_optval_uint(eq + 1);
-	if (what_matches(arg, "outstanding") && !soft)
-		quota_req_outstanding = val;
-	else if (what_matches(arg, "transaction-nodes") && !soft)
-		quota_trans_nodes = val;
-	else if (what_matches(arg, "memory")) {
-		if (soft)
-			quota_memory_per_domain_soft = val;
-		else
-			quota_memory_per_domain_hard = val;
-	} else
-		barf("unknown quota \"%s\"\n", arg);
+
+	for (i = 0; i < ACC_N; i++) {
+		if (what_matches(arg, q[i].name)) {
+			q[i].val = val;
+			return;
+		}
+	}
+
+	barf("unknown quota \"%s\"\n", arg);
 }
 
 /* Sorted by bit values of TRACE_* flags. Flag is (1u << index). */
@@ -2819,7 +2820,7 @@ int main(int argc, char *argv[])
 			no_domain_init = true;
 			break;
 		case 'E':
-			quota_nb_entry_per_domain = strtol(optarg, NULL, 10);
+			hard_quotas[ACC_NODES].val = strtoul(optarg, NULL, 10);
 			break;
 		case 'F':
 			pidfile = optarg;
@@ -2837,10 +2838,10 @@ int main(int argc, char *argv[])
 			recovery = false;
 			break;
 		case 'S':
-			quota_max_entry_size = strtol(optarg, NULL, 10);
+			hard_quotas[ACC_NODESZ].val = strtoul(optarg, NULL, 10);
 			break;
 		case 't':
-			quota_max_transaction = strtol(optarg, NULL, 10);
+			hard_quotas[ACC_TRANS].val = strtoul(optarg, NULL, 10);
 			break;
 		case 'T':
 			tracefile = optarg;
@@ -2860,15 +2861,17 @@ int main(int argc, char *argv[])
 			verbose = true;
 			break;
 		case 'W':
-			quota_nb_watch_per_domain = strtol(optarg, NULL, 10);
+			hard_quotas[ACC_WATCH].val = strtoul(optarg, NULL, 10);
 			break;
 		case 'A':
-			quota_nb_perms_per_node = strtol(optarg, NULL, 10);
+			hard_quotas[ACC_NPERM].val = strtoul(optarg, NULL, 10);
 			break;
 		case 'M':
-			quota_max_path_len = strtol(optarg, NULL, 10);
-			quota_max_path_len = min(XENSTORE_REL_PATH_MAX,
-						 quota_max_path_len);
+			hard_quotas[ACC_PATHLEN].val =
+				strtoul(optarg, NULL, 10);
+			hard_quotas[ACC_PATHLEN].val =
+				 min((unsigned int)XENSTORE_REL_PATH_MAX,
+				     hard_quotas[ACC_PATHLEN].val);
 			break;
 		case 'Q':
 			set_quota(optarg, false);

tools/xenstore/xenstored_core.h

@@ -316,16 +316,6 @@ extern TDB_CONTEXT *tdb_ctx;
 extern int dom0_domid;
 extern int dom0_event;
 extern int priv_domid;
-extern int quota_nb_watch_per_domain;
-extern int quota_max_transaction;
-extern int quota_max_entry_size;
-extern int quota_nb_perms_per_node;
-extern int quota_max_path_len;
-extern int quota_nb_entry_per_domain;
-extern int quota_req_outstanding;
-extern int quota_trans_nodes;
-extern int quota_memory_per_domain_soft;
-extern int quota_memory_per_domain_hard;
 extern bool keep_orphans;
 
 extern unsigned int timeout_watch_event_msec;

tools/xenstore/xenstored_domain.c

@@ -43,7 +43,61 @@ static evtchn_port_t virq_port;
 
 xenevtchn_handle *xce_handle = NULL;
 
-static unsigned int acc_global_max[ACC_N];
+struct quota hard_quotas[ACC_N] = {
+	[ACC_NODES] = {
+		.name = "nodes",
+		.descr = "Nodes per domain",
+		.val = 1000,
+	},
+	[ACC_WATCH] = {
+		.name = "watches",
+		.descr = "Watches per domain",
+		.val = 128,
+	},
+	[ACC_OUTST] = {
+		.name = "outstanding",
+		.descr = "Outstanding requests per domain",
+		.val = 20,
+	},
+	[ACC_MEM] = {
+		.name = "memory",
+		.descr = "Total Xenstore memory per domain (error level)",
+		.val = 2 * 1024 * 1024 + 512 * 1024,	/* 2.5 MB */
+	},
+	[ACC_TRANS] = {
+		.name = "transactions",
+		.descr = "Active transactions per domain",
+		.val = 10,
+	},
+	[ACC_TRANSNODES] = {
+		.name = "transaction-nodes",
+		.descr = "Max. number of accessed nodes per transaction",
+		.val = 1024,
+	},
+	[ACC_NPERM] = {
+		.name = "node-permissions",
+		.descr = "Max. number of permissions per node",
+		.val = 5,
+	},
+	[ACC_PATHLEN] = {
+		.name = "path-max",
+		.descr = "Max. length of a node path",
+		.val = XENSTORE_REL_PATH_MAX,
+	},
+	[ACC_NODESZ] = {
+		.name = "node-size",
+		.descr = "Max. size of a node",
+		.val = 2048,
+	},
+};
+
+struct quota soft_quotas[ACC_N] = {
+	[ACC_MEM] = {
+		.name = "memory",
+		.descr = "Total Xenstore memory per domain (warning level)",
+		.val = 2 * 1024 * 1024,			/* 2.0 MB */
+	},
+};
 
 struct domain
 {
@@ -204,10 +258,10 @@ static bool domain_can_read(struct connection *conn)
 	if (domain_is_unprivileged(conn)) {
 		if (domain->wrl_credit < 0)
 			return false;
-		if (domain->acc[ACC_OUTST].val >= quota_req_outstanding)
+		if (domain->acc[ACC_OUTST].val >= hard_quotas[ACC_OUTST].val)
 			return false;
-		if (domain->acc[ACC_MEM].val >= quota_memory_per_domain_hard &&
-		    quota_memory_per_domain_hard)
+		if (domain->acc[ACC_MEM].val >= hard_quotas[ACC_MEM].val &&
+		    hard_quotas[ACC_MEM].val)
 			return false;
 	}
 
@@ -421,6 +475,7 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 {
 	struct domain *d = find_domain_struct(domid);
 	char *resp;
+	unsigned int i;
 
 	if (!d)
 		return ENOENT;
@@ -429,22 +484,15 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 	if (!resp)
 		return ENOMEM;
 
-#define ent(t, e) \
-	resp = talloc_asprintf_append(resp, "%-17s: %8u (max: %8u\n", #t, \
-				      d->acc[e].val, d->acc[e].max); \
-	if (!resp) return ENOMEM
-
-	ent(nodes, ACC_NODES);
-	ent(watches, ACC_WATCH);
-	ent(transactions, ACC_TRANS);
-	ent(outstanding, ACC_OUTST);
-	ent(memory, ACC_MEM);
-	ent(transaction-nodes, ACC_TRANSNODES);
-	ent(node-permissions, ACC_NPERM);
-	ent(path-length, ACC_PATHLEN);
-	ent(node-size, ACC_NODESZ);
-
-#undef ent
+	for (i = 0; i < ACC_N; i++) {
+		if (!hard_quotas[i].name)
+			continue;
+		resp = talloc_asprintf_append(resp, "%-17s: %8u (max %8u)\n",
+					      hard_quotas[i].name,
+					      d->acc[i].val, d->acc[i].max);
+		if (!resp)
+			return ENOMEM;
+	}
 
 	send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
 
@@ -454,27 +502,21 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 int domain_max_global_acc(const void *ctx, struct connection *conn)
 {
 	char *resp;
+	unsigned int i;
 
 	resp = talloc_asprintf(ctx, "Max. seen accounting values:\n");
 	if (!resp)
 		return ENOMEM;
 
-#define ent(t, e) \
-	resp = talloc_asprintf_append(resp, "%-17s: %8u\n", #t,   \
-				      acc_global_max[e]);         \
-	if (!resp) return ENOMEM
-
-	ent(nodes, ACC_NODES);
-	ent(watches, ACC_WATCH);
-	ent(transactions, ACC_TRANS);
-	ent(outstanding, ACC_OUTST);
-	ent(memory, ACC_MEM);
-	ent(transaction-nodes, ACC_TRANSNODES);
-	ent(node-permissions, ACC_NPERM);
-	ent(path-length, ACC_PATHLEN);
-	ent(node-size, ACC_NODESZ);
-
-#undef ent
+	for (i = 0; i < ACC_N; i++) {
+		if (!hard_quotas[i].name)
+			continue;
+		resp = talloc_asprintf_append(resp, "%-17s: %8u\n",
+					      hard_quotas[i].name,
+					      hard_quotas[i].max);
+		if (!resp)
+			return ENOMEM;
+	}
 
 	send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
 
@@ -589,7 +631,7 @@ int acc_fix_domains(struct list_head *head, bool chk_quota, bool update)
 	list_for_each_entry(cd, head, list) {
 		cnt = domain_nbentry_fix(cd->domid, cd->acc[ACC_NODES], update);
 		if (!update) {
-			if (chk_quota && cnt >= quota_nb_entry_per_domain)
+			if (chk_quota && cnt >= hard_quotas[ACC_NODES].val)
 				return ENOSPC;
 			if (cnt < 0)
 				return ENOMEM;
@@ -1090,12 +1132,12 @@ static void domain_acc_valid_max(struct domain *d, enum accitem what,
 				 unsigned int val)
 {
 	assert(what < ARRAY_SIZE(d->acc));
-	assert(what < ARRAY_SIZE(acc_global_max));
+	assert(what < ARRAY_SIZE(hard_quotas));
 
 	if (val > d->acc[what].max)
 		d->acc[what].max = val;
-	if (val > acc_global_max[what] && domid_is_unprivileged(d->domid))
-		acc_global_max[what] = val;
+	if (val > hard_quotas[what].max && domid_is_unprivileged(d->domid))
+		hard_quotas[what].max = val;
 }
 
 static int domain_acc_add_valid(struct domain *d, enum accitem what, int add)
@@ -1232,19 +1274,19 @@ void domain_reset_global_acc(void)
 	unsigned int i;
 
 	for (i = 0; i < ACC_N; i++)
-		acc_global_max[i] = 0;
+		hard_quotas[i].max = 0;
 
 	/* Set current max values seen. */
 	hashtable_iterate(domhash, domain_reset_global_acc_sub, NULL);
 }
 
 bool domain_max_chk(const struct connection *conn, enum accitem what,
-		    unsigned int val, unsigned int quota)
+		    unsigned int val)
 {
 	if (!conn || !conn->domain)
 		return false;
 
-	if (domain_is_unprivileged(conn) && val > quota)
+	if (domain_is_unprivileged(conn) && val > hard_quotas[what].val)
 		return true;
 
 	domain_acc_valid_max(conn->domain, what, val);
@@ -1293,8 +1335,7 @@ static bool domain_chk_quota(struct connection *conn, unsigned int mem)
 	domain = conn->domain;
 	now = time(NULL);
 
-	if (mem >= quota_memory_per_domain_hard &&
-	    quota_memory_per_domain_hard) {
+	if (mem >= hard_quotas[ACC_MEM].val && hard_quotas[ACC_MEM].val) {
 		if (domain->hard_quota_reported)
 			return true;
 		syslog(LOG_ERR, "Domain %u exceeds hard memory quota, Xenstore interface to domain stalled\n",
@@ -1311,15 +1352,14 @@ static bool domain_chk_quota(struct connection *conn, unsigned int mem)
 			syslog(LOG_INFO, "Domain %u below hard memory quota again\n",
 			       domain->domid);
 		}
-		if (mem >= quota_memory_per_domain_soft &&
-		    quota_memory_per_domain_soft &&
-		    !domain->soft_quota_reported) {
+		if (mem >= soft_quotas[ACC_MEM].val &&
+		    soft_quotas[ACC_MEM].val && !domain->soft_quota_reported) {
 			domain->mem_last_msg = now;
 			domain->soft_quota_reported = true;
 			syslog(LOG_WARNING, "Domain %u exceeds soft memory quota\n",
 			       domain->domid);
 		}
-		if (mem < quota_memory_per_domain_soft &&
+		if (mem < soft_quotas[ACC_MEM].val &&
 		    domain->soft_quota_reported) {
 			domain->mem_last_msg = now;
 			domain->soft_quota_reported = false;

tools/xenstore/xenstored_domain.h

@@ -40,6 +40,16 @@ enum accitem {
 	ACC_N,			/* Number of elements per domain. */
 };
 
+struct quota {
+	const char *name;
+	const char *descr;
+	unsigned int val;
+	unsigned int max;
+};
+
+extern struct quota hard_quotas[ACC_N];
+extern struct quota soft_quotas[ACC_N];
+
 void handle_event(void);
 
 void check_domains(void);
@@ -134,7 +144,7 @@ void acc_commit(struct connection *conn);
 int domain_max_global_acc(const void *ctx, struct connection *conn);
 void domain_reset_global_acc(void);
 bool domain_max_chk(const struct connection *conn, unsigned int what,
-		    unsigned int val, unsigned int quota);
+		    unsigned int val);
 
 /* Write rate limiting */
 

tools/xenstore/xenstored_transaction.c

@@ -252,8 +252,7 @@ int access_node(struct connection *conn, struct node *node,
 
 	i = find_accessed_node(trans, node->name);
 	if (!i) {
-		if (domain_max_chk(conn, ACC_TRANSNODES, trans->nodes + 1,
-				   quota_trans_nodes)) {
+		if (domain_max_chk(conn, ACC_TRANSNODES, trans->nodes + 1)) {
 			ret = ENOSPC;
 			goto err;
 		}
@@ -479,7 +478,7 @@ int do_transaction_start(const void *ctx, struct connection *conn,
 	if (conn->transaction)
 		return EBUSY;
 
-	if (domain_transaction_get(conn) > quota_max_transaction)
+	if (domain_transaction_get(conn) > hard_quotas[ACC_TRANS].val)
 		return ENOSPC;
 
 	/* Attach transaction to ctx for autofree until it's complete */

tools/xenstore/xenstored_watch.c

@@ -239,7 +239,7 @@ int do_watch(const void *ctx, struct connection *conn, struct buffered_data *in)
 			return EEXIST;
 	}
 
-	if (domain_watch(conn) > quota_nb_watch_per_domain)
+	if (domain_watch(conn) > hard_quotas[ACC_WATCH].val)
 		return E2BIG;
 
 	watch = add_watch(conn, vec[0], vec[1], relative, false);