xenstore: call each xenstored command function with temporary context

In order to be able to avoid leaving temporary memory allocated after
processing of a command in xenstored call all command functions with
the temporary "in" context. Each function can then make use of that
temporary context for allocating temporary memory instead of either
leaving that memory allocated until the connection is dropped (or
even until end of xenstored) or freeing the memory itself.

This requires to modify the interfaces of the functions taking only
one argument from the connection by moving the call of onearg() into
the single functions. Other than that no functional change.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 51fb0b3fc1db49de20f4be5d9715200e8491b7fd..accca82069adbad03fabd67f2f84c472b2f117ef 100644 (file)
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -723,7 +723,7 @@ bool is_valid_nodename(const char *node)
 /* We expect one arg in the input: return NULL otherwise.
  * The payload must contain exactly one nul, at the end.
  */
-static const char *onearg(struct buffered_data *in)
+const char *onearg(struct buffered_data *in)
 {
        if (!in->used || get_string(in, 0) != in->used)
                return NULL;
@@ -771,9 +771,10 @@ bool check_event_node(const char *node)
        return true;
 }
 
-static void send_directory(struct connection *conn, const char *name)
+static void send_directory(struct connection *conn, struct buffered_data *in)
 {
        struct node *node;
+       const char *name = onearg(in);
 
        name = canonicalize(conn, name);
        node = get_node(conn, name, XS_PERM_READ);
@@ -785,9 +786,10 @@ static void send_directory(struct connection *conn, const char *name)
        send_reply(conn, XS_DIRECTORY, node->children, node->childlen);
 }
 
-static void do_read(struct connection *conn, const char *name)
+static void do_read(struct connection *conn, struct buffered_data *in)
 {
        struct node *node;
+       const char *name = onearg(in);
 
        name = canonicalize(conn, name);
        node = get_node(conn, name, XS_PERM_READ);
@@ -953,9 +955,10 @@ static void do_write(struct connection *conn, struct buffered_data *in)
        send_ack(conn, XS_WRITE);
 }
 
-static void do_mkdir(struct connection *conn, const char *name)
+static void do_mkdir(struct connection *conn, struct buffered_data *in)
 {
        struct node *node;
+       const char *name = onearg(in);
 
        name = canonicalize(conn, name);
        node = get_node(conn, name, XS_PERM_WRITE);
@@ -1070,9 +1073,10 @@ static void internal_rm(const char *name)
 }
 
 
-static void do_rm(struct connection *conn, const char *name)
+static void do_rm(struct connection *conn, struct buffered_data *in)
 {
        struct node *node;
+       const char *name = onearg(in);
 
        name = canonicalize(conn, name);
        node = get_node(conn, name, XS_PERM_WRITE);
@@ -1104,9 +1108,10 @@ static void do_rm(struct connection *conn, const char *name)
 }
 
 
-static void do_get_perms(struct connection *conn, const char *name)
+static void do_get_perms(struct connection *conn, struct buffered_data *in)
 {
        struct node *node;
+       const char *name = onearg(in);
        char *strings;
        unsigned int len;
 
@@ -1220,11 +1225,11 @@ static void process_message(struct connection *conn, struct buffered_data *in)
 
        switch (in->hdr.msg.type) {
        case XS_DIRECTORY:
-               send_directory(conn, onearg(in));
+               send_directory(conn, in);
                break;
 
        case XS_READ:
-               do_read(conn, onearg(in));
+               do_read(conn, in);
                break;
 
        case XS_WRITE:
@@ -1232,15 +1237,15 @@ static void process_message(struct connection *conn, struct buffered_data *in)
                break;
 
        case XS_MKDIR:
-               do_mkdir(conn, onearg(in));
+               do_mkdir(conn, in);
                break;
 
        case XS_RM:
-               do_rm(conn, onearg(in));
+               do_rm(conn, in);
                break;
 
        case XS_GET_PERMS:
-               do_get_perms(conn, onearg(in));
+               do_get_perms(conn, in);
                break;
 
        case XS_SET_PERMS:
@@ -1264,7 +1269,7 @@ static void process_message(struct connection *conn, struct buffered_data *in)
                break;
 
        case XS_TRANSACTION_END:
-               do_transaction_end(conn, onearg(in));
+               do_transaction_end(conn, in);
                break;
 
        case XS_INTRODUCE:
@@ -1272,19 +1277,19 @@ static void process_message(struct connection *conn, struct buffered_data *in)
                break;
 
        case XS_IS_DOMAIN_INTRODUCED:
-               do_is_domain_introduced(conn, onearg(in));
+               do_is_domain_introduced(conn, in);
                break;
 
        case XS_RELEASE:
-               do_release(conn, onearg(in));
+               do_release(conn, in);
                break;
 
        case XS_GET_DOMAIN_PATH:
-               do_get_domain_path(conn, onearg(in));
+               do_get_domain_path(conn, in);
                break;
 
        case XS_RESUME:
-               do_resume(conn, onearg(in));
+               do_resume(conn, in);
                break;
 
        case XS_SET_TARGET:
@@ -1292,7 +1297,7 @@ static void process_message(struct connection *conn, struct buffered_data *in)
                break;
 
        case XS_RESET_WATCHES:
-               do_reset_watches(conn);
+               do_reset_watches(conn, in);
                break;
 
        default:

diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 3a497f758a05522d5b08b0b114928bfcd8bfeeda..5dbf9c816f56294f74331e4c2c25208b6ea17045 100644 (file)
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -122,6 +122,9 @@ struct node {
        char *children;
 };
 
+/* Return the only argument in the input. */
+const char *onearg(struct buffered_data *in);
+
 /* Break input into vectors, return the number, fill in up to num of them. */
 unsigned int get_strings(struct buffered_data *data,
                         char *vec[], unsigned int num);

diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 47b4f03156e34baf962793dd61f72128f4aa6b2d..c66539a6efea087995072ef6f6eef940fdb0bd07 100644 (file)
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -453,8 +453,9 @@ void do_set_target(struct connection *conn, struct buffered_data *in)
 }
 
 /* domid */
-void do_release(struct connection *conn, const char *domid_str)
+void do_release(struct connection *conn, struct buffered_data *in)
 {
+       const char *domid_str = onearg(in);
        struct domain *domain;
        unsigned int domid;
 
@@ -490,10 +491,11 @@ void do_release(struct connection *conn, const char *domid_str)
        send_ack(conn, XS_RELEASE);
 }
 
-void do_resume(struct connection *conn, const char *domid_str)
+void do_resume(struct connection *conn, struct buffered_data *in)
 {
        struct domain *domain;
        unsigned int domid;
+       const char *domid_str = onearg(in);
 
        if (!domid_str) {
                send_error(conn, EINVAL);
@@ -527,9 +529,10 @@ void do_resume(struct connection *conn, const char *domid_str)
        send_ack(conn, XS_RESUME);
 }
 
-void do_get_domain_path(struct connection *conn, const char *domid_str)
+void do_get_domain_path(struct connection *conn, struct buffered_data *in)
 {
        char *path;
+       const char *domid_str = onearg(in);
 
        if (!domid_str) {
                send_error(conn, EINVAL);
@@ -543,10 +546,11 @@ void do_get_domain_path(struct connection *conn, const char *domid_str)
        talloc_free(path);
 }
 
-void do_is_domain_introduced(struct connection *conn, const char *domid_str)
+void do_is_domain_introduced(struct connection *conn, struct buffered_data *in)
 {
        int result;
        unsigned int domid;
+       const char *domid_str = onearg(in);
 
        if (!domid_str) {
                send_error(conn, EINVAL);
@@ -563,7 +567,7 @@ void do_is_domain_introduced(struct connection *conn, const char *domid_str)
 }
 
 /* Allow guest to reset all watches */
-void do_reset_watches(struct connection *conn)
+void do_reset_watches(struct connection *conn, struct buffered_data *in)
 {
        conn_delete_all_watches(conn);
        conn_delete_all_transactions(conn);

diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index 83488edd4b434554d4eae9b869817ae1603c12c2..2554423f00584de88652aba3a582fcee2f2063a8 100644 (file)
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -25,22 +25,22 @@ void handle_event(void);
 void do_introduce(struct connection *conn, struct buffered_data *in);
 
 /* domid */
-void do_is_domain_introduced(struct connection *conn, const char *domid_str);
+void do_is_domain_introduced(struct connection *conn, struct buffered_data *in);
 
 /* domid */
-void do_release(struct connection *conn, const char *domid_str);
+void do_release(struct connection *conn, struct buffered_data *in);
 
 /* domid */
-void do_resume(struct connection *conn, const char *domid_str);
+void do_resume(struct connection *conn, struct buffered_data *in);
 
 /* domid, target */
 void do_set_target(struct connection *conn, struct buffered_data *in);
 
 /* domid */
-void do_get_domain_path(struct connection *conn, const char *domid_str);
+void do_get_domain_path(struct connection *conn, struct buffered_data *in);
 
 /* Allow guest to reset all watches */
-void do_reset_watches(struct connection *conn);
+void do_reset_watches(struct connection *conn, struct buffered_data *in);
 
 void domain_init(void);
 

diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c
index d0e47399808395021bbd9fc220cf1348f6b6eb7c..3cde26e532426f139f711e3633254b0cfcfcc8f0 100644 (file)
--- a/tools/xenstore/xenstored_transaction.c
+++ b/tools/xenstore/xenstored_transaction.c
@@ -184,8 +184,9 @@ void do_transaction_start(struct connection *conn, struct buffered_data *in)
        send_reply(conn, XS_TRANSACTION_START, id_str, strlen(id_str)+1);
 }
 
-void do_transaction_end(struct connection *conn, const char *arg)
+void do_transaction_end(struct connection *conn, struct buffered_data *in)
 {
+       const char *arg = onearg(in);
        struct changed_node *i;
        struct changed_domain *d;
        struct transaction *trans;

diff --git a/tools/xenstore/xenstored_transaction.h b/tools/xenstore/xenstored_transaction.h
index cfeeae1ae0f05f231bcfa32aabde6e04d7711efc..0c868ee504ee53e4bf60a4c486019c352e6f287c 100644 (file)
--- a/tools/xenstore/xenstored_transaction.h
+++ b/tools/xenstore/xenstored_transaction.h
@@ -22,7 +22,7 @@
 struct transaction;
 
 void do_transaction_start(struct connection *conn, struct buffered_data *node);
-void do_transaction_end(struct connection *conn, const char *arg);
+void do_transaction_end(struct connection *conn, struct buffered_data *in);
 
 struct transaction *transaction_lookup(struct connection *conn, uint32_t id);