notify.c

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	for (i=0;i<d->num_entries;i++) {
		d->max_mask |= d->entries[i].filter;
		d->max_mask_subdir |= d->entries[i].subdir_filter;
	}

	return notify_save(notify);
}

/*
  add a notify watch. This is called when a notify is first setup on a open
  directory handle.
*/
NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
		    void (*callback)(void *, const struct notify_event *), 
		    void *private_data)
{
	struct notify_entry e = *e0;
	NTSTATUS status;
	char *tmp_path = NULL;
	struct notify_list *listel;
	size_t len;
	int depth;

	/* see if change notify is enabled at all */
	if (notify == NULL) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}

	status = notify_lock(notify);
	NT_STATUS_NOT_OK_RETURN(status);

	status = notify_load(notify);
	if (!NT_STATUS_IS_OK(status)) {
		goto done;
	}

	/* cope with /. on the end of the path */
	len = strlen(e.path);
	if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
		tmp_path = talloc_strndup(notify, e.path, len-2);
		if (tmp_path == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto done;
		}
		e.path = tmp_path;
	}

	depth = count_chars(e.path, '/');

	listel = talloc_zero(notify, struct notify_list);
	if (listel == NULL) {
		status = NT_STATUS_NO_MEMORY;
		goto done;
	}

	listel->private_data = private_data;
	listel->callback = callback;
	listel->depth = depth;
	DLIST_ADD(notify->list, listel);

	/* ignore failures from sys_notify */
	if (notify->sys_notify_ctx != NULL) {
		/*
		  this call will modify e.filter and e.subdir_filter
		  to remove bits handled by the backend
		*/
		status = sys_notify_watch(notify->sys_notify_ctx, &e,
					  sys_notify_callback, listel, 
					  &listel->sys_notify_handle);
		if (NT_STATUS_IS_OK(status)) {
			talloc_steal(listel, listel->sys_notify_handle);
		}
	}

	/* if the system notify handler couldn't handle some of the
	   filter bits, or couldn't handle a request for recursion
	   then we need to install it in the array used for the
	   intra-samba notify handling */
	if (e.filter != 0 || e.subdir_filter != 0) {
		status = notify_add_array(notify, &e, private_data, depth);
	}

done:
	notify_unlock(notify);
	talloc_free(tmp_path);

	return status;
}

/*
  remove a notify watch. Called when the directory handle is closed
*/
NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
{
	NTSTATUS status;
	struct notify_list *listel;
	int i, depth;
	struct notify_depth *d;

	/* see if change notify is enabled at all */
	if (notify == NULL) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}

	for (listel=notify->list;listel;listel=listel->next) {
		if (listel->private_data == private_data) {
			DLIST_REMOVE(notify->list, listel);
			break;
		}
	}
	if (listel == NULL) {
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	depth = listel->depth;

	talloc_free(listel);

	status = notify_lock(notify);
	NT_STATUS_NOT_OK_RETURN(status);

	status = notify_load(notify);
	if (!NT_STATUS_IS_OK(status)) {
		notify_unlock(notify);
		return status;
	}

	if (depth >= notify->array->num_depths) {
		notify_unlock(notify);
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	/* we only have to search at the depth of this element */
	d = &notify->array->depth[depth];

	for (i=0;i<d->num_entries;i++) {
		if (private_data == d->entries[i].private_data &&
		    cluster_id_equal(&notify->server, &d->entries[i].server)) {
			break;
		}
	}
	if (i == d->num_entries) {
		notify_unlock(notify);
		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
	}

	if (i < d->num_entries-1) {
		memmove(&d->entries[i], &d->entries[i+1], 
			sizeof(d->entries[i])*(d->num_entries-(i+1)));
	}
	d->num_entries--;

	status = notify_save(notify);

	notify_unlock(notify);

	return status;
}

/*
  remove all notify watches for this messaging server
*/
static NTSTATUS notify_remove_all(struct notify_context *notify)
{
	NTSTATUS status;
	int i, depth, del_count=0;

	if (notify->list == NULL) {
		return NT_STATUS_OK;
	}

	status = notify_lock(notify);
	NT_STATUS_NOT_OK_RETURN(status);

	status = notify_load(notify);
	if (!NT_STATUS_IS_OK(status)) {
		notify_unlock(notify);
		return status;
	}

	/* we have to search for all entries across all depths, looking for matches
	   for our server id */
	for (depth=0;depth<notify->array->num_depths;depth++) {
		struct notify_depth *d = &notify->array->depth[depth];
		for (i=0;i<d->num_entries;i++) {
			if (cluster_id_equal(&notify->server, &d->entries[i].server)) {
				if (i < d->num_entries-1) {
					memmove(&d->entries[i], &d->entries[i+1], 
						sizeof(d->entries[i])*(d->num_entries-(i+1)));
				}
				i--;
				d->num_entries--;
				del_count++;
			}
		}
	}

	if (del_count > 0) {
		status = notify_save(notify);
	}

	notify_unlock(notify);

	return status;
}


/*
  send a notify message to another messaging server
*/
static void notify_send(struct notify_context *notify, struct notify_entry *e,
			const char *path, uint32_t action)
{
	struct notify_event ev;
	DATA_BLOB data;
	NTSTATUS status;
	enum ndr_err_code ndr_err;
	TALLOC_CTX *tmp_ctx;

	ev.action = action;
	ev.path = path;
	ev.private_data = e->private_data;

	tmp_ctx = talloc_new(notify);

	ndr_err = ndr_push_struct_blob(&data, tmp_ctx, notify->iconv_convenience, &ev, (ndr_push_flags_fn_t)ndr_push_notify_event);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		talloc_free(tmp_ctx);
		return;
	}

	status = messaging_send(notify->messaging_ctx, e->server, 
				MSG_PVFS_NOTIFY, &data);
	talloc_free(tmp_ctx);
}


/*
  trigger a notify message for anyone waiting on a matching event

  This function is called a lot, and needs to be very fast. The unusual data structure
  and traversal is designed to be fast in the average case, even for large numbers of
  notifies
*/
void notify_trigger(struct notify_context *notify,
		    uint32_t action, uint32_t filter, const char *path)
{
	NTSTATUS status;
	int depth;
	const char *p, *next_p;

	/* see if change notify is enabled at all */
	if (notify == NULL) {
		return;
	}

	status = notify_load(notify);
	if (!NT_STATUS_IS_OK(status)) {
		return;
	}

	/* loop along the given path, working with each directory depth separately */
	for (depth=0,p=path;
	     p && depth < notify->array->num_depths;
	     p=next_p,depth++) {
		int p_len = p - path;
		int min_i, max_i, i;
		struct notify_depth *d = &notify->array->depth[depth];
		next_p = strchr(p+1, '/');

		/* see if there are any entries at this depth */
		if (d->num_entries == 0) continue;
		
		/* try to skip based on the maximum mask. If next_p is
		 NULL then we know it will be a 'this directory'
		 match, otherwise it must be a subdir match */
		if (next_p != NULL) {
			if (0 == (filter & d->max_mask_subdir)) {
				continue;
			}
		} else {
			if (0 == (filter & d->max_mask)) {
				continue;
			}
		}

		/* we know there is an entry here worth looking
		 for. Use a bisection search to find the first entry
		 with a matching path */
		min_i = 0;
		max_i = d->num_entries-1;

		while (min_i < max_i) {
			struct notify_entry *e;
			int cmp;
			i = (min_i+max_i)/2;
			e = &d->entries[i];
			cmp = strncmp(path, e->path, p_len);
			if (cmp == 0) {
				if (p_len == e->path_len) {
					max_i = i;
				} else {
					max_i = i-1;
				}
			} else if (cmp < 0) {
				max_i = i-1;
			} else {
				min_i = i+1;
			}
		}

		if (min_i != max_i) {
			/* none match */
			continue;
		}

		/* we now know that the entries start at min_i */
		for (i=min_i;i<d->num_entries;i++) {
			struct notify_entry *e = &d->entries[i];
			if (p_len != e->path_len ||
			    strncmp(path, e->path, p_len) != 0) break;
			if (next_p != NULL) {
				if (0 == (filter & e->subdir_filter)) {
					continue;
				}
			} else {
				if (0 == (filter & e->filter)) {
					continue;
				}
			}
			notify_send(notify, e, path + e->path_len + 1, action);
		}
	}
}