w1: hold bus_mutex in netlink and search
The bus_mutex needs to be taken to serialize access to a specific bus.
netlink wasn't updated when bus_mutex was added and was calling
without that lock held, and not all of the masters were holding the
bus_mutex in a search. This was causing the ds2490 hardware to stop
responding when both netlink and /sys slaves were executing bus
commands at the same time.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c
index a5dc219..5234964 100644
--- a/drivers/w1/w1_netlink.c
+++ b/drivers/w1/w1_netlink.c
@@ -246,11 +246,16 @@
{
int err = -EINVAL;
+ /* drop bus_mutex for search (does it's own locking), and add/remove
+ * which doesn't use the bus
+ */
switch (req_cmd->cmd) {
case W1_CMD_SEARCH:
case W1_CMD_ALARM_SEARCH:
case W1_CMD_LIST_SLAVES:
+ mutex_unlock(&dev->bus_mutex);
err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
+ mutex_lock(&dev->bus_mutex);
break;
case W1_CMD_READ:
case W1_CMD_WRITE:
@@ -262,8 +267,12 @@
break;
case W1_CMD_SLAVE_ADD:
case W1_CMD_SLAVE_REMOVE:
+ mutex_unlock(&dev->bus_mutex);
+ mutex_lock(&dev->mutex);
err = w1_process_command_addremove(dev, req_msg, req_hdr,
req_cmd);
+ mutex_unlock(&dev->mutex);
+ mutex_lock(&dev->bus_mutex);
break;
default:
err = -EINVAL;
@@ -400,7 +409,7 @@
struct w1_slave *sl = node->sl;
struct w1_netlink_cmd *cmd = NULL;
- mutex_lock(&dev->mutex);
+ mutex_lock(&dev->bus_mutex);
dev->portid = node->block->portid;
if (sl && w1_reset_select_slave(sl))
err = -ENODEV;
@@ -437,7 +446,7 @@
else
atomic_dec(&dev->refcnt);
dev->portid = 0;
- mutex_unlock(&dev->mutex);
+ mutex_unlock(&dev->bus_mutex);
mutex_lock(&dev->list_mutex);
list_del(&async_cmd->async_entry);