w1: fixup search to support abort from netlink
Before 63706172f33 "rework kthread_stop()" kthread_should_stop()
always returned false when called from a non-kthread task, after it
would oops as a non-kthread didn't have that structure and netlink was
calling search from a thread which wasn't a kthread. 9d1817cab2f030
"w1: fix oops when w1_search is called from netlink connector",
modified the code to avoid calling kthread_stop from a netlink thread.
Introduce a w1_master flag and bit W1_ABORT_SEARCH to identify abort
to cleanly support both kthread and netlink search abort. A search
can take seconds to run, so it is important to abort early if the
hardware is removed in the middle of a search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Marcin Jurkowski <marcin1j@gmail.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 590bd8a..423f3c2 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -172,6 +172,7 @@
#if 0 /* Thread cleanup code, not required currently. */
err_out_kill_thread:
+ set_bit(W1_ABORT_SEARCH, &dev->flags);
kthread_stop(dev->thread);
#endif
err_out_rm_attr:
@@ -187,6 +188,7 @@
struct w1_netlink_msg msg;
struct w1_slave *sl, *sln;
+ set_bit(W1_ABORT_SEARCH, &dev->flags);
kthread_stop(dev->thread);
mutex_lock(&w1_mlock);