f2fs: support statx

Last kernel has already support new syscall statx() in commit a528d35e
("statx: Add a system call to make enhanced file info available"), with
this interface we can show more file info including file creation and some
attribute flags to user.

This patch tries to support this functionality.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -633,9 +633,30 @@ int f2fs_truncate(struct inode *inode)
 }
 
 int f2fs_getattr(const struct path *path, struct kstat *stat,
-		 u32 request_mask, unsigned int flags)
+		 u32 request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_inode(path->dentry);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	unsigned int flags;
+
+	flags = fi->i_flags & FS_FL_USER_VISIBLE;
+	if (flags & FS_APPEND_FL)
+		stat->attributes |= STATX_ATTR_APPEND;
+	if (flags & FS_COMPR_FL)
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+	if (f2fs_encrypted_inode(inode))
+		stat->attributes |= STATX_ATTR_ENCRYPTED;
+	if (flags & FS_IMMUTABLE_FL)
+		stat->attributes |= STATX_ATTR_IMMUTABLE;
+	if (flags & FS_NODUMP_FL)
+		stat->attributes |= STATX_ATTR_NODUMP;
+
+	stat->attributes_mask |= (STATX_ATTR_APPEND |
+				  STATX_ATTR_COMPRESSED |
+				  STATX_ATTR_ENCRYPTED |
+				  STATX_ATTR_IMMUTABLE |
+				  STATX_ATTR_NODUMP);
+
 	generic_fillattr(inode, stat);
 	stat->blocks <<= 3;
 	return 0;