[PATCH v2] block: move definition of blk_qc_t to types.h

[Jeffle Xu <jefflexu@linux.alibaba.com>]

So that kiocb.ki_cookie can be defined as blk_qc_t, which will enforce
the encapsulation.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
---
changes since v1: add trivial comments 
---
 include/linux/blk_types.h | 2 +-
 include/linux/fs.h        | 2 +-
 include/linux/types.h     | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 866f74261b3b..2e05244fc16d 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -532,7 +532,7 @@ static inline int op_stat_group(unsigned int op)
 	return op_is_write(op);
 }
 
-typedef unsigned int blk_qc_t;
+/* Macros for blk_qc_t */
 #define BLK_QC_T_NONE		-1U
 #define BLK_QC_T_SHIFT		16
 #define BLK_QC_T_INTERNAL	(1U << 31)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ad4cf1bae586..58db714c4834 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -330,7 +330,7 @@ struct kiocb {
 	u16			ki_hint;
 	u16			ki_ioprio; /* See linux/ioprio.h */
 	union {
-		unsigned int		ki_cookie; /* for ->iopoll */
+		blk_qc_t		ki_cookie; /* for ->iopoll */
 		struct wait_page_queue	*ki_waitq; /* for async buffered IO */
 	};
 
diff --git a/include/linux/types.h b/include/linux/types.h
index a147977602b5..da5ca7e1bea9 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -125,6 +125,9 @@ typedef s64			int64_t;
 typedef u64 sector_t;
 typedef u64 blkcnt_t;
 
+/* cookie used for iopoll */
+typedef unsigned int blk_qc_t;
+
 /*
  * The type of an index into the pagecache.
  */
-- 
2.27.0