block: ioc_task_link() can't fail
ioc_task_link() is used to share %current's ioc on clone. If
%current->io_context is set, %current is guaranteed to have refcount
on the ioc and, thus, ioc_task_link() can't fail.
Replace error checking in ioc_task_link() with WARN_ON_ONCE() and make
it just increment refcount and nr_tasks.
-v2: Description typo fix (Vivek).
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index 1a30180..81a8870 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -120,18 +120,12 @@
struct work_struct release_work;
};
-static inline struct io_context *ioc_task_link(struct io_context *ioc)
+static inline void ioc_task_link(struct io_context *ioc)
{
- /*
- * if ref count is zero, don't allow sharing (ioc is going away, it's
- * a race).
- */
- if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
- atomic_inc(&ioc->nr_tasks);
- return ioc;
- }
-
- return NULL;
+ WARN_ON_ONCE(atomic_long_read(&ioc->refcount) <= 0);
+ WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);
+ atomic_long_inc(&ioc->refcount);
+ atomic_inc(&ioc->nr_tasks);
}
struct task_struct;