[Virtio-fs] [PATCH v8 3/7] fuse: support per inode DAX in fuse protocol

[Jeffle Xu]

Expand the fuse protocol to support per inode DAX.

FUSE_HAS_INODE_DAX flag is added indicating if fuse server/client
supporting per inode DAX. It can be conveyed in both FUSE_INIT request
and reply.

FUSE_ATTR_DAX flag is added indicating if DAX shall be enabled for
corresponding file. It is conveyed in FUSE_LOOKUP reply.

Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>
---
 include/uapi/linux/fuse.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index a1dc3ee1d17c..63a9a963f4d9 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -187,6 +187,7 @@
  *
  *  7.35
  *  - add FOPEN_NOFLUSH
+ *  - add FUSE_HAS_INODE_DAX, FUSE_ATTR_DAX
  */
 
 #ifndef _LINUX_FUSE_H
@@ -341,6 +342,7 @@ struct fuse_file_lock {
  *			write/truncate sgid is killed only if file has group
  *			execute permission. (Same as Linux VFS behavior).
  * FUSE_SETXATTR_EXT:	Server supports extended struct fuse_setxattr_in
+ * FUSE_HAS_INODE_DAX:  use per inode DAX
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -372,6 +374,7 @@ struct fuse_file_lock {
 #define FUSE_SUBMOUNTS		(1 << 27)
 #define FUSE_HANDLE_KILLPRIV_V2	(1 << 28)
 #define FUSE_SETXATTR_EXT	(1 << 29)
+#define FUSE_HAS_INODE_DAX	(1 << 30)
 
 /**
  * CUSE INIT request/reply flags
@@ -454,8 +457,10 @@ struct fuse_file_lock {
  * fuse_attr flags
  *
  * FUSE_ATTR_SUBMOUNT: Object is a submount root
+ * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
  */
 #define FUSE_ATTR_SUBMOUNT      (1 << 0)
+#define FUSE_ATTR_DAX		(1 << 1)
 
 /**
  * Open flags
-- 
2.27.0