Merge branch 'vfs-6.14.poll' into vfs.fixes

Bring in the fixes for __pollwait() and waitqueue_active() interactions.

Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 12 insertions, 14 deletions

diff --git a/include/linux/poll.h b/include/linux/poll.h
index d1ea4f3714a8..12bb18e8b978 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -25,14 +25,14 @@
 
 struct poll_table_struct;
 
-/* 
+/*
  * structures and helpers for f_op->poll implementations
  */
 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
 
 /*
- * Do not touch the structure directly, use the access functions
- * poll_does_not_wait() and poll_requested_events() instead.
+ * Do not touch the structure directly, use the access function
+ * poll_requested_events() instead.
  */
 typedef struct poll_table_struct {
 	poll_queue_proc _qproc;
@@ -41,18 +41,16 @@ typedef struct poll_table_struct {
 
 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
 {
-	if (p && p->_qproc && wait_address)
+	if (p && p->_qproc) {
 		p->_qproc(filp, wait_address, p);
-}
-
-/*
- * Return true if it is guaranteed that poll will not wait. This is the case
- * if the poll() of another file descriptor in the set got an event, so there
- * is no need for waiting.
- */
-static inline bool poll_does_not_wait(const poll_table *p)
-{
-	return p == NULL || p->_qproc == NULL;
+		/*
+		 * This memory barrier is paired in the wq_has_sleeper().
+		 * See the comment above prepare_to_wait(), we need to
+		 * ensure that subsequent tests in this thread can't be
+		 * reordered with __add_wait_queue() in _qproc() paths.
+		 */
+		smp_mb();
+	}
 }
 
 /*