[RFC PATCH 1/4] block: introduce async ioctl operation

[Kanchan Joshi]

Add a new block-dev operation for async-ioctl.
Driver managing the block-dev can choose to implement it.

Signed-off-by: Kanchan Joshi <josh...@samsung.com>
---
 include/linux/blkdev.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f94ee3089e01..c9f6cc26d675 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1848,6 +1848,16 @@ static inline void blk_ksm_unregister(struct 
request_queue *q) { }
 
 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
 
+struct pt_ioctl_ctx {
+       /* submitter task context */
+       struct task_struct *task;
+       /* callback supplied by upper layer */
+       void (*pt_complete)(struct pt_ioctl_ctx *ptioc, long ret);
+       /* driver-allocated data */
+       void *ioc_data;
+       /* to schedule task-work */
+       struct callback_head pt_work;
+};
 
 struct block_device_operations {
        blk_qc_t (*submit_bio) (struct bio *bio);
@@ -1856,6 +1866,8 @@ struct block_device_operations {
        int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned 
int);
        int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
        int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned 
long);
+       int (*async_ioctl) (struct block_device *, fmode_t, unsigned, unsigned 
long,
+                               struct pt_ioctl_ctx *);
        unsigned int (*check_events) (struct gendisk *disk,
                                      unsigned int clearing);
        void (*unlock_native_capacity) (struct gendisk *);
-- 
2.25.1