[PATCH 10/11] mm: add kiocb_wait_page_async_init() helper

From: Jens Axboe
Date: Fri May 22 2020 - 21:51:19 EST


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@xxxxxxxxx>
---
include/linux/pagemap.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index e260bcd071e4..21ced353310a 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -468,6 +468,24 @@ struct wait_page_async {
struct wait_page_key key;
};

+static inline int kiocb_wait_page_async_init(struct kiocb *kiocb,
+ struct wait_page_async *wait,
+ wait_queue_func_t func,
+ void *data)
+{
+ 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->private = 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_async *wait);
--
2.26.2