compat: sync compat_stats with statfs.

This was found by inspection while tracking a similar
bug in compat_statfs64, that has been fixed in mainline
since decemeber.

- This fixes a bug where not all of the f_spare fields
  were cleared on mips and s390.
- Add the f_flags field to struct compat_statfs
- Copy f_flags to userspace in case someone cares.
- Use __clear_user to copy the f_spare field to userspace
  to ensure that all of the elements of f_spare are cleared.
  On some architectures f_spare is has 5 ints and on some
  architectures f_spare only has 4 ints.  Which makes
  the previous technique of clearing each int individually
  broken.

I don't expect anyone actually uses the old statfs system
call anymore but if they do let them benefit from having
the compat and the native version working the same.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

6 files changed, 12 insertions, 6 deletions

diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index dbc51065df5..b77df0366ee 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -111,7 +111,8 @@ struct compat_statfs {
 	int		f_bavail;
 	compat_fsid_t	f_fsid;
 	int		f_namelen;
-	int		f_spare[6];
+	int		f_flags;
+	int		f_spare[5];
 };
 
 #define COMPAT_RLIM_INFINITY	0x7fffffffUL
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index efa0b60c63f..760f331d4fa 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -105,7 +105,8 @@ struct compat_statfs {
 	__kernel_fsid_t	f_fsid;
 	s32		f_namelen;
 	s32		f_frsize;
-	s32		f_spare[5];
+	s32		f_flags;
+	s32		f_spare[4];
 };
 
 struct compat_sigcontext {
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 91010e8f847..88e602f6430 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -100,7 +100,8 @@ struct compat_statfs {
 	compat_fsid_t	f_fsid;
 	int		f_namelen;	/* SunOS ignores this field. */
 	int		f_frsize;
-	int		f_spare[5];
+	int		f_flags;
+	int		f_spare[4];
 };
 
 #define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index da359ca6fe5..cdb9b78f6c0 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -131,7 +131,8 @@ struct compat_statfs {
 	compat_fsid_t	f_fsid;
 	s32		f_namelen;
 	s32		f_frsize;
-	s32		f_spare[6];
+	s32		f_flags;
+	s32		f_spare[5];
 };
 
 #define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 6f57325bb88..b8be20d42a0 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -134,7 +134,8 @@ struct compat_statfs {
 	compat_fsid_t	f_fsid;
 	int		f_namelen;	/* SunOS ignores this field. */
 	int		f_frsize;
-	int		f_spare[5];
+	int		f_flags;
+	int		f_spare[4];
 };
 
 #define COMPAT_RLIM_INFINITY 0x7fffffff
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 1d9cd27c292..30d737ef2a4 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -108,7 +108,8 @@ struct compat_statfs {
 	compat_fsid_t	f_fsid;
 	int		f_namelen;	/* SunOS ignores this field. */
 	int		f_frsize;
-	int		f_spare[5];
+	int		f_flags;
+	int		f_spare[4];
 };
 
 #define COMPAT_RLIM_OLD_INFINITY	0x7fffffff