[11/12] mm: add kiocb_wait_page_queue_init() helper
diff mbox series

Message ID 20200526195123.29053-12-axboe@kernel.dk
State New
Headers show
Series
  • Add support for async buffered reads
Related show

Commit Message

Jens Axboe May 26, 2020, 7:51 p.m. UTC
Checks if the file supports it, and initializes the values that we need.
Caller passes in 'data' pointer, if any, and the callback function to
be used.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/pagemap.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

Comments

Johannes Weiner May 26, 2020, 10:01 p.m. UTC | #1
On Tue, May 26, 2020 at 01:51:22PM -0600, Jens Axboe wrote:
> Checks if the file supports it, and initializes the values that we need.
> Caller passes in 'data' pointer, if any, and the callback function to
> be used.
> 
> Signed-off-by: Jens Axboe <axboe@kernel.dk>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Patch
diff mbox series

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index d3e63c9c61ae..8b65420410ee 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -493,6 +493,27 @@  static inline int wake_page_match(struct wait_page_queue *wait_page,
 	return 1;
 }
 
+static inline int kiocb_wait_page_queue_init(struct kiocb *kiocb,
+					     struct wait_page_queue *wait,
+					     wait_queue_func_t func,
+					     void *data)
+{
+	/* Can't support async wakeup with polled IO */
+	if (kiocb->ki_flags & IOCB_HIPRI)
+		return -EINVAL;
+	if (kiocb->ki_filp->f_mode & FMODE_BUF_RASYNC) {
+		wait->wait.func = func;
+		wait->wait.private = data;
+		wait->wait.flags = 0;
+		INIT_LIST_HEAD(&wait->wait.entry);
+		kiocb->ki_flags |= IOCB_WAITQ;
+		kiocb->ki_waitq = wait;
+		return 0;
+	}
+
+	return -EOPNOTSUPP;
+}
+
 extern void __lock_page(struct page *page);
 extern int __lock_page_killable(struct page *page);
 extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);