* U = upper file handle
* L = lower file handle
*
- * (*) Connecting an overlay dir from real lower dentry is not always
+ * (*) Decoding a connected overlay dir from real lower dentry is not always
* possible when there are redirects in lower layers and non-indexed merge dirs.
* To mitigate those case, we may copy up the lower dir ancestor before encode
- * a lower dir file handle.
+ * of a decodable file handle for non-upper dir.
*
* Return 0 for upper file handle, > 0 for lower file handle or < 0 on error.
*/
static int ovl_check_encode_origin(struct dentry *dentry)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
+ bool decodable = ofs->config.nfs_export;
+
+ /* Lower file handle for non-upper non-decodable */
+ if (!ovl_dentry_upper(dentry) && !decodable)
+ return 0;
/* Upper file handle for pure upper */
if (!ovl_dentry_lower(dentry))
return 0;
/*
- * Upper file handle for non-indexed upper.
- *
* Root is never indexed, so if there's an upper layer, encode upper for
* root.
*/
- if (ovl_dentry_upper(dentry) &&
+ if (dentry == dentry->d_sb->s_root)
+ return 0;
+
+ /*
+ * Upper decodable file handle for non-indexed upper.
+ */
+ if (ovl_dentry_upper(dentry) && decodable &&
!ovl_test_flag(OVL_INDEX, d_inode(dentry)))
return 0;
* ovl_connect_layer() will try to make origin's layer "connected" by
* copying up a "connectable" ancestor.
*/
- if (d_is_dir(dentry) && ovl_upper_mnt(ofs))
+ if (d_is_dir(dentry) && ovl_upper_mnt(ofs) && decodable)
return ovl_connect_layer(dentry);
/* Lower file handle for indexed and non-upper dir/non-dir */
.get_name = ovl_get_name,
.get_parent = ovl_get_parent,
};
+
+/* encode_fh() encodes non-decodable file handles with nfs_export=off */
+const struct export_operations ovl_export_fid_operations = {
+ .encode_fh = ovl_encode_fh,
+};
pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
name);
}
+ ofs->nofh |= !fh_type;
/*
* Decoding origin file handle is required for persistent st_ino.
* Without persistent st_ino, xino=auto falls back to xino=off.
ofs->config.index = false;
pr_warn("upper fs does not support file handles, falling back to index=off.\n");
}
+ ofs->nofh |= !fh_type;
/* Check if upper fs has 32bit inode numbers */
if (fh_type != FILEID_INO32_GEN)
ofs->config.nfs_export = false;
}
+ /*
+ * Support encoding decodable file handles with nfs_export=on
+ * and encoding non-decodable file handles with nfs_export=off
+ * if all layers support file handles.
+ */
if (ofs->config.nfs_export)
sb->s_export_op = &ovl_export_operations;
+ else if (!ofs->nofh)
+ sb->s_export_op = &ovl_export_fid_operations;
/* Never override disk quota limits or use reserved space */
cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);