add f_flags to struct statfs(64)

Add a flags field to help glibc implementing statvfs(3) efficiently.

We copy the flag values from glibc, and add a new ST_VALID flag to
denote that f_flags is implemented.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/mips/include/asm/statfs.h b/arch/mips/include/asm/statfs.h
index c3ddf97..0f805c7 100644
--- a/arch/mips/include/asm/statfs.h
+++ b/arch/mips/include/asm/statfs.h
@@ -33,7 +33,8 @@
 	/* Linux specials */
 	__kernel_fsid_t	f_fsid;
 	long		f_namelen;
-	long		f_spare[6];
+	long		f_flags;
+	long		f_spare[5];
 };
 
 #if (_MIPS_SIM == _MIPS_SIM_ABI32) || (_MIPS_SIM == _MIPS_SIM_NABI32)
@@ -53,7 +54,8 @@
 	__u64	f_bavail;
 	__kernel_fsid_t f_fsid;
 	__u32	f_namelen;
-	__u32	f_spare[6];
+	__u32	f_flags;
+	__u32	f_spare[5];
 };
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
@@ -73,7 +75,8 @@
 	/* Linux specials */
 	__kernel_fsid_t	f_fsid;
 	long		f_namelen;
-	long		f_spare[6];
+	long		f_flags;
+	long		f_spare[5];
 };
 
 struct compat_statfs64 {
@@ -88,7 +91,8 @@
 	__u64	f_bavail;
 	__kernel_fsid_t f_fsid;
 	__u32	f_namelen;
-	__u32	f_spare[6];
+	__u32	f_flags;
+	__u32	f_spare[5];
 };
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */