[PATCH v5 21/36] debugfs: Make debugfs_cancellation a context lock struct

[Marco Elver]

When compiling include/linux/debugfs.h with CONTEXT_ANALYSIS enabled, we
can see this error:

./include/linux/debugfs.h:239:17: error: use of undeclared identifier 'cancellation'
  239 | void __acquires(cancellation)

Move the __acquires(..) attribute after the declaration, so that the
compiler can see the cancellation function argument, as well as making
struct debugfs_cancellation a real context lock to benefit from Clang's
context analysis.

This change is a preparatory change to allow enabling context analysis
in subsystems that include the above header.

Signed-off-by: Marco Elver <elver at google.com>
---
v5:
* Rename "context guard" -> "context lock".

v4:
* Rename capability -> context analysis.
---
 include/linux/debugfs.h | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 7cecda29447e..4177c4738282 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -239,18 +239,16 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
  * @cancel: callback to call
  * @cancel_data: extra data for the callback to call
  */
-struct debugfs_cancellation {
+context_lock_struct(debugfs_cancellation) {
 	struct list_head list;
 	void (*cancel)(struct dentry *, void *);
 	void *cancel_data;
 };
 
-void __acquires(cancellation)
-debugfs_enter_cancellation(struct file *file,
-			   struct debugfs_cancellation *cancellation);
-void __releases(cancellation)
-debugfs_leave_cancellation(struct file *file,
-			   struct debugfs_cancellation *cancellation);
+void debugfs_enter_cancellation(struct file *file,
+				struct debugfs_cancellation *cancellation) __acquires(cancellation);
+void debugfs_leave_cancellation(struct file *file,
+				struct debugfs_cancellation *cancellation) __releases(cancellation);
 
 #else
 
-- 
2.52.0.322.g1dd061c0dc-goog