static void
mdeg_notify_client(void *arg)
{
mdeg_clnt_t *clnt = (mdeg_clnt_t *)arg;
md_diff_cookie_t mdd = MD_INVAL_DIFF_COOKIE;
mdeg_result_t mdeg_res;
mde_cookie_t md_prev_start;
mde_cookie_t md_curr_start;
/*
* mdeg.rwlock must be held as a reader while this function
* executes. However, we do not need to acquire the lock as a
* reader here because it is held as a reader by the thread
* executing mdeg_notify_clients which triggers the execution
* of this function from a taskq. Since mdeg_notify_clients
* holds the lock as a reader until the taskq callbacks have
* completed, it will be held for the life of this function call.
* Furthermore, we must not attempt to acquire the lock as a
* reader with rw_enter because if there is a pending writer,
* we will block, creating a circular deadlock with this function,
* the writer, and mdeg_notify_clients. Since we do not need
* to acquire the lock, just assert that it is held.
*/
ASSERT(RW_READ_HELD(&mdeg.rwlock));
if (!mdeg.enabled) {
/* trying to shutdown */
MDEG_DBG("mdeg_notify_client: mdeg disabled, aborting\n");
goto cleanup;
}
/*
* Handle the special case where the node specification
* is NULL. In this case, call the client callback without
* any results. All processing is left to the client.
*/
if (clnt->pspec == NULL) {
/* call the client callback */
(*clnt->cb)(clnt->cb_arg, NULL);
MDEG_DBG("MDEG client callback done\n");
goto cleanup;
}
/* find our start nodes */
md_prev_start = mdeg_find_start_node(mdeg.md_prev, clnt->pspec);
if (md_prev_start == MDE_INVAL_ELEM_COOKIE) {
goto cleanup;
}
md_curr_start = mdeg_find_start_node(mdeg.md_curr, clnt->pspec);
if (md_curr_start == MDE_INVAL_ELEM_COOKIE) {
goto cleanup;
}
/* diff the MDs */
mdd = md_diff_init(mdeg.md_prev, md_prev_start, mdeg.md_curr,
md_curr_start, clnt->nmatch->namep, clnt->nmatch->matchp);
if (mdd == MD_INVAL_DIFF_COOKIE) {
MDEG_DBG("unable to diff MDs\n");
goto cleanup;
}
/*
* Cache the results of the diff
*/
mdeg_get_diff_results(mdd, &mdeg_res);
/* call the client callback */
(*clnt->cb)(clnt->cb_arg, &mdeg_res);
MDEG_DBG("MDEG client callback done\n");
cleanup:
if (mdd != MD_INVAL_DIFF_COOKIE)
(void) md_diff_fini(mdd);
}
static void
mdeg_notify_client(void *arg)
{
mdeg_clnt_t *clnt = (mdeg_clnt_t *)arg;
md_diff_cookie_t mdd = MD_INVAL_DIFF_COOKIE;
mdeg_result_t mdeg_res;
mde_cookie_t md_prev_start;
mde_cookie_t md_curr_start;
rw_enter(&mdeg.rwlock, RW_READER);
if (!mdeg.enabled) {
/* trying to shutdown */
MDEG_DBG("mdeg_notify_client: mdeg disabled, aborting\n");
goto cleanup;
}
/*
* Handle the special case where the node specification
* is NULL. In this case, call the client callback without
* any results. All processing is left to the client.
*/
if (clnt->pspec == NULL) {
/* call the client callback */
(*clnt->cb)(clnt->cb_arg, NULL);
MDEG_DBG("MDEG client callback done\n");
goto cleanup;
}
/* find our start nodes */
md_prev_start = mdeg_find_start_node(mdeg.md_prev, clnt->pspec);
if (md_prev_start == MDE_INVAL_ELEM_COOKIE) {
goto cleanup;
}
md_curr_start = mdeg_find_start_node(mdeg.md_curr, clnt->pspec);
if (md_curr_start == MDE_INVAL_ELEM_COOKIE) {
goto cleanup;
}
/* diff the MDs */
mdd = md_diff_init(mdeg.md_prev, md_prev_start, mdeg.md_curr,
md_curr_start, clnt->nmatch->namep, clnt->nmatch->matchp);
if (mdd == MD_INVAL_DIFF_COOKIE) {
MDEG_DBG("unable to diff MDs\n");
goto cleanup;
}
/*
* Cache the results of the diff
*/
mdeg_get_diff_results(mdd, &mdeg_res);
/* call the client callback */
(*clnt->cb)(clnt->cb_arg, &mdeg_res);
MDEG_DBG("MDEG client callback done\n");
cleanup:
rw_exit(&mdeg.rwlock);
if (mdd != MD_INVAL_DIFF_COOKIE)
(void) md_diff_fini(mdd);
}
