2 files changed, 21 insertions, 1 deletions

diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index 3e445a760f14..b075f601919b 100644
--- a/include/uapi/linux/falloc.h
+++ b/include/uapi/linux/falloc.h
@@ -58,4 +58,22 @@
  */
 #define FALLOC_FL_INSERT_RANGE          0x20
 
+/*
+ * FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the
+ * file size without overwriting any existing data. The purpose of this
+ * call is to preemptively reallocate any blocks that are subject to
+ * copy-on-write.
+ *
+ * Different filesystems may implement different limitations on the
+ * granularity of the operation. Most will limit operations to filesystem
+ * block size boundaries, but this boundary may be larger or smaller
+ * depending on the filesystem and/or the configuration of the filesystem
+ * or file.
+ *
+ * This flag can only be used with allocate-mode fallocate, which is
+ * to say that it cannot be used with the punch, zero, collapse, or
+ * insert range modes.
+ */
+#define FALLOC_FL_UNSHARE_RANGE         0x40
+
 #endif /* _UAPI_FALLOC_H_ */
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 2473272169f2..acb2b6152ba0 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -158,7 +158,8 @@ struct fsxattr {
         __u32           fsx_extsize;    /* extsize field value (get/set)*/
         __u32           fsx_nextents;   /* nextents field value (get)   */
         __u32           fsx_projid;     /* project identifier (get/set) */
-        unsigned char   fsx_pad[12];
+        __u32           fsx_cowextsize; /* CoW extsize field value (get/set)*/
+        unsigned char   fsx_pad[8];
 };
 
 /*
@@ -179,6 +180,7 @@ 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_COWEXTSIZE     0x00010000      /* CoW extent size allocator hint */
 #define FS_XFLAG_HASATTR        0x80000000      /* no DIFLAG for this   */
 
 /* the read-only stuff doesn't really belong here, but any other place is