rcutorture: Abstract torture_shutdown_absorb()

Because handling races between rmmod and normal shutdown is not specific
to rcutorture, this commit renames rcutorture_shutdown_absorb() to
torture_shutdown_absorb() and pulls it out into then kernel/torture.c
module.  This implies pulling the fullstop mechanism into kernel/torture.c
as well.

The exporting of fullstop and fullstop_mutex is ugly and must die.
And it does in fact die in later commits that introduce higher-level
APIs that encapsulate both of these variables.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>`

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/torture.h b/include/linux/torture.h
index 09be8887fb0..8474d776c86 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -41,6 +41,18 @@
 	module_param(name, type, 0444); \
 	MODULE_PARM_DESC(name, msg);
 
+/* Mediate rmmod and system shutdown.  Concurrent rmmod & shutdown illegal! */
+#define FULLSTOP_DONTSTOP 0	/* Normal operation. */
+#define FULLSTOP_SHUTDOWN 1	/* System shutdown with rcutorture running. */
+#define FULLSTOP_RMMOD    2	/* Normal rmmod of rcutorture. */
+extern int fullstop;
+/* Protect fullstop transitions and spawning of kthreads.  */
+extern struct mutex fullstop_mutex;
+
+/* Common module parameters. */
+extern char *torture_type;
+extern bool verbose;
+
 #define TORTURE_FLAG "-torture:"
 #define TOROUT_STRING(s) \
 	pr_alert("%s" TORTURE_FLAG s "\n", torture_type)
@@ -57,4 +69,7 @@ struct torture_random_state {
 #define DEFINE_TORTURE_RANDOM(name) struct torture_random_state name = { 0, 0 }
 unsigned long torture_random(struct torture_random_state *trsp);
 
+/* Shutdown task absorption, for when the tasks cannot safely be killed. */
+void torture_shutdown_absorb(const char *title);
+
 #endif /* __LINUX_TORTURE_H */