[PATCH 099/145] xfs: support FS_XFLAG_REFLINK on reflink filesystems

[Darrick J. Wong]

Add support for reporting the "reflink" inode flag in the XFS-specific
getxflags ioctl, and allow the user to clear the flag if file size is
zero.

v2: Move the reflink flag out of the way of the DAX flag, and add the
new cowextsize flag.

v3: do not report (or allow changes to) FL_NOCOW_FL, since we don't
support a flag to prevent CoWing and the reflink flag is a poor
proxy.  We'll try to design away the need for the NOCOW flag.

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
 include/darwin.h  |    2 ++
 include/freebsd.h |    2 ++
 include/irix.h    |    2 ++
 include/linux.h   |    2 ++
 4 files changed, 8 insertions(+)


diff --git a/include/darwin.h b/include/darwin.h
index 2935b4c..abb2a22 100644
--- a/include/darwin.h
+++ b/include/darwin.h
@@ -314,6 +314,8 @@ struct fsxattr {
 #define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
+#define FS_XFLAG_REFLINK	0x00010000	/* file is reflinked */
+#define FS_XFLAG_COWEXTSIZE	0x00020000	/* CoW extent size allocator hint */
 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
 
 #define FS_IOC_FSGETXATTR     _IOR ('X', 31, struct fsxattr)
diff --git a/include/freebsd.h b/include/freebsd.h
index 3feca07..fc58a74 100644
--- a/include/freebsd.h
+++ b/include/freebsd.h
@@ -204,6 +204,8 @@ struct fsxattr {
 #define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
+#define FS_XFLAG_REFLINK	0x00010000	/* file is reflinked */
+#define FS_XFLAG_COWEXTSIZE	0x00020000	/* CoW extent size allocator hint */
 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
 
 #define FS_IOC_FSGETXATTR     _IOR ('X', 31, struct fsxattr)
diff --git a/include/irix.h b/include/irix.h
index 45c8594..c4d25b5 100644
--- a/include/irix.h
+++ b/include/irix.h
@@ -449,6 +449,8 @@ struct fsxattr {
 #define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
+#define FS_XFLAG_REFLINK	0x00010000	/* file is reflinked */
+#define FS_XFLAG_COWEXTSIZE	0x00020000	/* CoW extent size allocator hint */
 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
 
 #define FS_IOC_FSGETXATTR		F_FSGETXATTR
diff --git a/include/linux.h b/include/linux.h
index cd4b3eb..d47a29c 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -207,6 +207,8 @@ struct fsxattr {
 #define FS_XFLAG_NODEFRAG	0x00002000	/* do not defragment */
 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
+#define FS_XFLAG_REFLINK	0x00010000	/* file is reflinked */
+#define FS_XFLAG_COWEXTSIZE	0x00020000	/* CoW extent size allocator hint */
 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
 
 #define FS_IOC_FSGETXATTR     _IOR ('X', 31, struct fsxattr)