hostfs: fix UML crash: remove f_spare from hostfs

365b1818 ("add f_flags to struct statfs(64)") resized f_spare within
struct statfs which caused a UML crash.  There is no need to copy f_spare.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hostfs/hostfs.h

@@ -91,7 +91,6 @@ extern int rename_file(char *from, char *to);
 extern int do_statfs(char *root, long *bsize_out, long long *blocks_out,
 		     long long *bfree_out, long long *bavail_out,
 		     long long *files_out, long long *ffree_out,
-		     void *fsid_out, int fsid_size, long *namelen_out,
-		     long *spare_out);
+		     void *fsid_out, int fsid_size, long *namelen_out);
 
 #endif

fs/hostfs/hostfs_kern.c

@@ -217,7 +217,7 @@ int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
 	err = do_statfs(dentry->d_sb->s_fs_info,
 			&sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files,
 			&f_ffree, &sf->f_fsid, sizeof(sf->f_fsid),
-			&sf->f_namelen, sf->f_spare);
+			&sf->f_namelen);
 	if (err)
 		return err;
 	sf->f_blocks = f_blocks;

fs/hostfs/hostfs_user.c

@@ -364,8 +364,7 @@ int rename_file(char *from, char *to)
 int do_statfs(char *root, long *bsize_out, long long *blocks_out,
 	      long long *bfree_out, long long *bavail_out,
 	      long long *files_out, long long *ffree_out,
-	      void *fsid_out, int fsid_size, long *namelen_out,
-	      long *spare_out)
+	      void *fsid_out, int fsid_size, long *namelen_out)
 {
 	struct statfs64 buf;
 	int err;
@@ -384,10 +383,6 @@ int do_statfs(char *root, long *bsize_out, long long *blocks_out,
 	       sizeof(buf.f_fsid) > fsid_size ? fsid_size :
 	       sizeof(buf.f_fsid));
 	*namelen_out = buf.f_namelen;
-	spare_out[0] = buf.f_spare[0];
-	spare_out[1] = buf.f_spare[1];
-	spare_out[2] = buf.f_spare[2];
-	spare_out[3] = buf.f_spare[3];
-	spare_out[4] = buf.f_spare[4];
+
 	return 0;
 }