diff options
| author | David Fries <david@fries.net> | 2008-10-15 22:04:38 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:49 -0700 |
| commit | c30c9b15187e977ab5928f7276e9dfcd8d6f9460 (patch) | |
| tree | d36d7513c5acf1d39f581625ffa5c1915ae5627f /drivers/w1/w1_int.c | |
| parent | dd78c9439fc1e031835bccb934d27b978c72c536 (diff) | |
| download | linux-c30c9b15187e977ab5928f7276e9dfcd8d6f9460.tar.bz2 | |
W1: fix deadlocks and remove w1_control_thread
w1_control_thread was removed which would wake up every second and process
newly registered family codes and complete some final cleanup for a
removed master. Those routines were moved to the threads that were
previously requesting those operations. A new function
w1_reconnect_slaves takes care of reconnecting existing slave devices when
a new family code is registered or removed. The removal case was missing
and would cause a deadlock waiting for the family code reference count to
decrease, which will now happen. A problem with registering a family code
was fixed. A slave device would be unattached if it wasn't yet claimed,
then attached at the end of the list, two unclaimed slaves would cause an
infinite loop.
The struct w1_bus_master.search now takes a pointer to the struct
w1_master device to avoid searching for it, which would have caused a
lock ordering deadlock with the removal of w1_control_thread.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/w1/w1_int.c')
| -rw-r--r-- | drivers/w1/w1_int.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c index 6840dfebe4d4..ed3228017dad 100644 --- a/drivers/w1/w1_int.c +++ b/drivers/w1/w1_int.c @@ -148,10 +148,22 @@ err_out_free_dev: void __w1_remove_master_device(struct w1_master *dev) { struct w1_netlink_msg msg; + struct w1_slave *sl, *sln; set_bit(W1_MASTER_NEED_EXIT, &dev->flags); kthread_stop(dev->thread); + mutex_lock(&w1_mlock); + list_del(&dev->w1_master_entry); + mutex_unlock(&w1_mlock); + + mutex_lock(&dev->mutex); + list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) + w1_slave_detach(sl); + w1_destroy_master_attributes(dev); + mutex_unlock(&dev->mutex); + atomic_dec(&dev->refcnt); + while (atomic_read(&dev->refcnt)) { dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", dev->name, atomic_read(&dev->refcnt)); |