ovl: use ovl_do_getxattr() for private xattr

Use the convention of calling ovl_do_foo() for operations which are overlay
specific.

This patch is a no-op, and will have significance for supporting
"user.overlay." xattr namespace.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/inode.c

@@ -748,7 +748,8 @@ unsigned int ovl_get_nlink(struct dentry *lowerdentry,
 	if (!lowerdentry || !upperdentry || d_inode(lowerdentry)->i_nlink == 1)
 		return fallback;
 
-	err = vfs_getxattr(upperdentry, OVL_XATTR_NLINK, &buf, sizeof(buf) - 1);
+	err = ovl_do_getxattr(upperdentry, OVL_XATTR_NLINK,
+			      &buf, sizeof(buf) - 1);
 	if (err < 0)
 		goto fail;
 

fs/overlayfs/namei.c

@@ -109,7 +109,7 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
 	int res, err;
 	struct ovl_fh *fh = NULL;
 
-	res = vfs_getxattr(dentry, name, NULL, 0);
+	res = ovl_do_getxattr(dentry, name, NULL, 0);
 	if (res < 0) {
 		if (res == -ENODATA || res == -EOPNOTSUPP)
 			return NULL;
@@ -123,7 +123,7 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
 	if (!fh)
 		return ERR_PTR(-ENOMEM);
 
-	res = vfs_getxattr(dentry, name, fh->buf, res);
+	res = ovl_do_getxattr(dentry, name, fh->buf, res);
 	if (res < 0)
 		goto fail;
 

fs/overlayfs/overlayfs.h

@@ -170,6 +170,12 @@ static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
 	return err;
 }
 
+static inline ssize_t ovl_do_getxattr(struct dentry *dentry, const char *name,
+				      void *value, size_t size)
+{
+	return vfs_getxattr(dentry, name, value, size);
+}
+
 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
 				  const void *value, size_t size, int flags)
 {

fs/overlayfs/util.c

@@ -548,7 +548,7 @@ bool ovl_check_origin_xattr(struct dentry *dentry)
 {
 	int res;
 
-	res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
+	res = ovl_do_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
 
 	/* Zero size value means "copied up but origin unknown" */
 	if (res >= 0)
@@ -565,7 +565,7 @@ bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
 	if (!d_is_dir(dentry))
 		return false;
 
-	res = vfs_getxattr(dentry, name, &val, 1);
+	res = ovl_do_getxattr(dentry, name, &val, 1);
 	if (res == 1 && val == 'y')
 		return true;
 
@@ -853,7 +853,7 @@ int ovl_check_metacopy_xattr(struct dentry *dentry)
 	if (!S_ISREG(d_inode(dentry)->i_mode))
 		return 0;
 
-	res = vfs_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0);
+	res = ovl_do_getxattr(dentry, OVL_XATTR_METACOPY, NULL, 0);
 	if (res < 0) {
 		if (res == -ENODATA || res == -EOPNOTSUPP)
 			return 0;
@@ -887,7 +887,7 @@ char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
 	int res;
 	char *s, *next, *buf = NULL;
 
-	res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
+	res = ovl_do_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
 	if (res == -ENODATA || res == -EOPNOTSUPP)
 		return NULL;
 	if (res < 0)
@@ -899,7 +899,7 @@ char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 
-	res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
+	res = ovl_do_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
 	if (res < 0)
 		goto fail;
 	if (res == 0)