xfs: add XFS_IOC_FREE_EOFBLOCKS ioctl

The XFS_IOC_FREE_EOFBLOCKS ioctl allows users to invoke an EOFBLOCKS
scan. The xfs_eofblocks structure is defined to support the command
parameters (scan mode).

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index 0948c04..0cfa308 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -340,6 +340,22 @@
 
 
 /*
+ * Speculative preallocation trimming.
+ */
+#define XFS_EOFBLOCKS_VERSION		1
+struct xfs_eofblocks {
+	__u32		eof_version;
+	__u32		eof_flags;
+	__u64		pad[15];
+};
+
+/* eof_flags values */
+#define XFS_EOF_FLAGS_SYNC		(1 << 0) /* sync/wait mode scan */
+#define XFS_EOF_FLAGS_VALID	\
+	(XFS_EOF_FLAGS_SYNC)
+
+
+/*
  * The user-level Handle Request interface structure.
  */
 typedef struct xfs_fsop_handlereq {
@@ -457,6 +473,7 @@
 /*	XFS_IOC_GETBIOSIZE ---- deprecated 47	   */
 #define XFS_IOC_GETBMAPX	_IOWR('X', 56, struct getbmap)
 #define XFS_IOC_ZERO_RANGE	_IOW ('X', 57, struct xfs_flock64)
+#define XFS_IOC_FREE_EOFBLOCKS	_IOR ('X', 58, struct xfs_eofblocks)
 
 /*
  * ioctl commands that replace IRIX syssgi()'s