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path: root/drivers/xen/xenbus/xenbus_dev_frontend.c
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Diffstat (limited to 'drivers/xen/xenbus/xenbus_dev_frontend.c')
-rw-r--r--drivers/xen/xenbus/xenbus_dev_frontend.c49
1 files changed, 28 insertions, 21 deletions
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 6c0ead4be784..79130b310247 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -302,6 +302,29 @@ static void watch_fired(struct xenbus_watch *watch,
mutex_unlock(&adap->dev_data->reply_mutex);
}
+static int xenbus_command_reply(struct xenbus_file_priv *u,
+ unsigned int msg_type, const char *reply)
+{
+ struct {
+ struct xsd_sockmsg hdr;
+ const char body[16];
+ } msg;
+ int rc;
+
+ msg.hdr = u->u.msg;
+ msg.hdr.type = msg_type;
+ msg.hdr.len = strlen(reply) + 1;
+ if (msg.hdr.len > sizeof(msg.body))
+ return -E2BIG;
+
+ mutex_lock(&u->reply_mutex);
+ rc = queue_reply(&u->read_buffers, &msg, sizeof(msg.hdr) + msg.hdr.len);
+ wake_up(&u->read_waitq);
+ mutex_unlock(&u->reply_mutex);
+
+ return rc;
+}
+
static int xenbus_write_transaction(unsigned msg_type,
struct xenbus_file_priv *u)
{
@@ -316,12 +339,12 @@ static int xenbus_write_transaction(unsigned msg_type,
rc = -ENOMEM;
goto out;
}
- } else if (msg_type == XS_TRANSACTION_END) {
+ } else if (u->u.msg.tx_id != 0) {
list_for_each_entry(trans, &u->transactions, list)
if (trans->handle.id == u->u.msg.tx_id)
break;
if (&trans->list == &u->transactions)
- return -ESRCH;
+ return xenbus_command_reply(u, XS_ERROR, "ENOENT");
}
reply = xenbus_dev_request_and_reply(&u->u.msg);
@@ -372,12 +395,12 @@ static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
path = u->u.buffer + sizeof(u->u.msg);
token = memchr(path, 0, u->u.msg.len);
if (token == NULL) {
- rc = -EILSEQ;
+ rc = xenbus_command_reply(u, XS_ERROR, "EINVAL");
goto out;
}
token++;
if (memchr(token, 0, u->u.msg.len - (token - path)) == NULL) {
- rc = -EILSEQ;
+ rc = xenbus_command_reply(u, XS_ERROR, "EINVAL");
goto out;
}
@@ -411,23 +434,7 @@ static int xenbus_write_watch(unsigned msg_type, struct xenbus_file_priv *u)
}
/* Success. Synthesize a reply to say all is OK. */
- {
- struct {
- struct xsd_sockmsg hdr;
- char body[3];
- } __packed reply = {
- {
- .type = msg_type,
- .len = sizeof(reply.body)
- },
- "OK"
- };
-
- mutex_lock(&u->reply_mutex);
- rc = queue_reply(&u->read_buffers, &reply, sizeof(reply));
- wake_up(&u->read_waitq);
- mutex_unlock(&u->reply_mutex);
- }
+ rc = xenbus_command_reply(u, msg_type, "OK");
out:
return rc;