[v6,07/14] tools/xenstore: use accounting data array for per-domain values

Commit Message

Jürgen Groß May 30, 2023, 8:24 a.m. UTC

Add the accounting of per-domain usage of Xenstore memory, watches, and
outstanding requests to the array based mechanism.

Signed-off-by: Juergen Gross <[e-mail]>
Acked-by: Julien Grall <[e-mail]>
---
V5:
- drop domid parameter from domain_outstanding_inc() (Julien Grall)
---
 tools/xenstore/xenstored_core.c   |   4 +-
 tools/xenstore/xenstored_domain.c | 109 +++++++++++-------------------
 tools/xenstore/xenstored_domain.h |   8 ++-
 3 files changed, 48 insertions(+), 73 deletions(-)

Patch

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 006ad9224c..43b8772cb3 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -255,7 +255,7 @@  static void free_buffered_data(struct buffered_data *out,
 			req->pend.ref.event_cnt--;
 			if (!req->pend.ref.event_cnt && !req->on_out_list) {
 				if (req->on_ref_list) {
-					domain_outstanding_domid_dec(
+					domain_outstanding_dec(conn,
 						req->pend.ref.domid);
 					list_del(&req->list);
 				}
@@ -271,7 +271,7 @@  static void free_buffered_data(struct buffered_data *out,
 		out->on_ref_list = true;
 		return;
 	} else
-		domain_outstanding_dec(conn);
+		domain_outstanding_dec(conn, conn->id);
 
 	talloc_free(out);
 }
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 7770c4f395..a35ed97fd7 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -72,19 +72,12 @@  struct domain
 	/* Accounting data for this domain. */
 	unsigned int acc[ACC_N];
 
-	/* Amount of memory allocated for this domain. */
-	int memory;
+	/* Memory quota data for this domain. */
 	bool soft_quota_reported;
 	bool hard_quota_reported;
 	time_t mem_last_msg;
 #define MEM_WARN_MINTIME_SEC 10
 
-	/* number of watch for this domain */
-	int nbwatch;
-
-	/* Number of outstanding requests. */
-	int nboutstanding;
-
 	/* write rate limit */
 	wrl_creditt wrl_credit; /* [ -wrl_config_writecost, +_dburst ] */
 	struct wrl_timestampt wrl_timestamp;
@@ -200,14 +193,15 @@  static bool domain_can_write(struct connection *conn)
 
 static bool domain_can_read(struct connection *conn)
 {
-	struct xenstore_domain_interface *intf = conn->domain->interface;
+	struct domain *domain = conn->domain;
+	struct xenstore_domain_interface *intf = domain->interface;
 
 	if (domain_is_unprivileged(conn)) {
-		if (conn->domain->wrl_credit < 0)
+		if (domain->wrl_credit < 0)
 			return false;
-		if (conn->domain->nboutstanding >= quota_req_outstanding)
+		if (domain->acc[ACC_OUTST] >= quota_req_outstanding)
 			return false;
-		if (conn->domain->memory >= quota_memory_per_domain_hard &&
+		if (domain->acc[ACC_MEM] >= quota_memory_per_domain_hard &&
 		    quota_memory_per_domain_hard)
 			return false;
 	}
@@ -438,10 +432,10 @@  int domain_get_quota(const void *ctx, struct connection *conn,
 	if (!resp) return ENOMEM
 
 	ent(nodes, d->acc[ACC_NODES]);
-	ent(watches, d->nbwatch);
+	ent(watches, d->acc[ACC_WATCH]);
 	ent(transactions, ta);
-	ent(outstanding, d->nboutstanding);
-	ent(memory, d->memory);
+	ent(outstanding, d->acc[ACC_OUTST]);
+	ent(memory, d->acc[ACC_MEM]);
 
 #undef ent
 
@@ -1187,14 +1181,16 @@  unsigned int domain_nbentry(struct connection *conn)
 	       ? domain_acc_add(conn, conn->id, ACC_NODES, 0, true) : 0;
 }
 
-static bool domain_chk_quota(struct domain *domain, int mem)
+static bool domain_chk_quota(struct connection *conn, unsigned int mem)
 {
 	time_t now;
+	struct domain *domain;
 
-	if (!domain || !domid_is_unprivileged(domain->domid) ||
-	    (domain->conn && domain->conn->is_ignored))
+	if (!conn || !domid_is_unprivileged(conn->id) ||
+	    conn->is_ignored)
 		return false;
 
+	domain = conn->domain;
 	now = time(NULL);
 
 	if (mem >= quota_memory_per_domain_hard &&
@@ -1239,80 +1235,57 @@  static bool domain_chk_quota(struct domain *domain, int mem)
 int domain_memory_add(struct connection *conn, unsigned int domid, int mem,
 		      bool no_quota_check)
 {
-	struct domain *domain;
+	int ret;
 
-	domain = find_domain_struct(domid);
-	if (domain) {
-		/*
-		 * domain_chk_quota() will print warning and also store whether
-		 * the soft/hard quota has been hit. So check no_quota_check
-		 * *after*.
-		 */
-		if (domain_chk_quota(domain, domain->memory + mem) &&
-		    !no_quota_check)
-			return ENOMEM;
-		domain->memory += mem;
-	} else {
-		/*
-		 * The domain the memory is to be accounted for should always
-		 * exist, as accounting is done either for a domain related to
-		 * the current connection, or for the domain owning a node
-		 * (which is always existing, as the owner of the node is
-		 * tested to exist and deleted or replaced by domid 0 if not).
-		 * So not finding the related domain MUST be an error in the
-		 * data base.
-		 */
-		errno = ENOENT;
-		corrupt(NULL, "Accounting called for non-existing domain %u\n",
-			domid);
-		return ENOENT;
-	}
+	ret = domain_acc_add(conn, domid, ACC_MEM, 0, true);
+	if (ret < 0)
+		return -ret;
+
+	/*
+	 * domain_chk_quota() will print warning and also store whether the
+	 * soft/hard quota has been hit. So check no_quota_check *after*.
+	 */
+	if (domain_chk_quota(conn, ret + mem) && !no_quota_check)
+		return ENOMEM;
+
+	/*
+	 * The domain the memory is to be accounted for should always exist,
+	 * as accounting is done either for a domain related to the current
+	 * connection, or for the domain owning a node (which is always
+	 * existing, as the owner of the node is tested to exist and deleted
+	 * or replaced by domid 0 if not).
+	 * So not finding the related domain MUST be an error in the data base.
+	 */
+	domain_acc_add(conn, domid, ACC_MEM, mem, true);
 
 	return 0;
 }
 
 void domain_watch_inc(struct connection *conn)
 {
-	if (!conn || !conn->domain)
-		return;
-	conn->domain->nbwatch++;
+	domain_acc_add(conn, conn->id, ACC_WATCH, 1, true);
 }
 
 void domain_watch_dec(struct connection *conn)
 {
-	if (!conn || !conn->domain)
-		return;
-	if (conn->domain->nbwatch)
-		conn->domain->nbwatch--;
+	domain_acc_add(conn, conn->id, ACC_WATCH, -1, true);
 }
 
 int domain_watch(struct connection *conn)
 {
 	return (domain_is_unprivileged(conn))
-		? conn->domain->nbwatch
+		? domain_acc_add(conn, conn->id, ACC_WATCH, 0, true)
 		: 0;
 }
 
 void domain_outstanding_inc(struct connection *conn)
 {
-	if (!conn || !conn->domain)
-		return;
-	conn->domain->nboutstanding++;
+	domain_acc_add(conn, conn->id, ACC_OUTST, 1, true);
 }
 
-void domain_outstanding_dec(struct connection *conn)
+void domain_outstanding_dec(struct connection *conn, unsigned int domid)
 {
-	if (!conn || !conn->domain)
-		return;
-	conn->domain->nboutstanding--;
-}
-
-void domain_outstanding_domid_dec(unsigned int domid)
-{
-	struct domain *d = find_domain_by_domid(domid);
-
-	if (d)
-		d->nboutstanding--;
+	domain_acc_add(conn, domid, ACC_OUTST, -1, true);
 }
 
 static wrl_creditt wrl_config_writecost      = WRL_FACTOR;
diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index b94548fd7d..086133407b 100644
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -29,7 +29,10 @@  enum accitem {
 	ACC_REQ_N,		/* Number of elements per request. */
 	ACC_TR_N = ACC_REQ_N,	/* Number of elements per transaction. */
 	ACC_CHD_N = ACC_TR_N,	/* max(ACC_REQ_N, ACC_TR_N), for changed dom. */
-	ACC_N = ACC_TR_N,	/* Number of elements per domain. */
+	ACC_WATCH = ACC_TR_N,
+	ACC_OUTST,
+	ACC_MEM,
+	ACC_N,			/* Number of elements per domain. */
 };
 
 void handle_event(void);
@@ -109,8 +112,7 @@  void domain_watch_inc(struct connection *conn);
 void domain_watch_dec(struct connection *conn);
 int domain_watch(struct connection *conn);
 void domain_outstanding_inc(struct connection *conn);
-void domain_outstanding_dec(struct connection *conn);
-void domain_outstanding_domid_dec(unsigned int domid);
+void domain_outstanding_dec(struct connection *conn, unsigned int domid);
 int domain_get_quota(const void *ctx, struct connection *conn,
 		     unsigned int domid);