| /* |
| * GPL HEADER START |
| * |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 only, |
| * as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License version 2 for more details (a copy is included |
| * in the LICENSE file that accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License |
| * version 2 along with this program; If not, see |
| * http://www.gnu.org/licenses/gpl-2.0.html |
| * |
| * GPL HEADER END |
| */ |
| /* |
| * Copyright (c) 2013, 2014, Intel Corporation. |
| * Use is subject to license terms. |
| * |
| * Author: di wang <di.wang@intel.com> |
| */ |
| |
| /* There are several reasons to restrict the linkEA size: |
| * |
| * 1. Under DNE mode, if we do not restrict the linkEA size, and if there |
| * are too many cross-MDTs hard links to the same object, then it will |
| * casue the llog overflow. |
| * |
| * 2. Some backend has limited size for EA. For example, if without large |
| * EA enabled, the ldiskfs will make all EAs to share one (4K) EA block. |
| * |
| * 3. Too many entries in linkEA will seriously affect linkEA performance |
| * because we only support to locate linkEA entry consecutively. |
| */ |
| #define MAX_LINKEA_SIZE 4096 |
| |
| struct linkea_data { |
| /** |
| * Buffer to keep link EA body. |
| */ |
| struct lu_buf *ld_buf; |
| /** |
| * The matched header, entry and its length in the EA |
| */ |
| struct link_ea_header *ld_leh; |
| struct link_ea_entry *ld_lee; |
| int ld_reclen; |
| }; |
| |
| int linkea_data_new(struct linkea_data *ldata, struct lu_buf *buf); |
| int linkea_init(struct linkea_data *ldata); |
| int linkea_init_with_rec(struct linkea_data *ldata); |
| void linkea_entry_unpack(const struct link_ea_entry *lee, int *reclen, |
| struct lu_name *lname, struct lu_fid *pfid); |
| int linkea_entry_pack(struct link_ea_entry *lee, const struct lu_name *lname, |
| const struct lu_fid *pfid); |
| int linkea_add_buf(struct linkea_data *ldata, const struct lu_name *lname, |
| const struct lu_fid *pfid); |
| void linkea_del_buf(struct linkea_data *ldata, const struct lu_name *lname); |
| int linkea_links_find(struct linkea_data *ldata, const struct lu_name *lname, |
| const struct lu_fid *pfid); |
| |
| static inline void linkea_first_entry(struct linkea_data *ldata) |
| { |
| LASSERT(ldata); |
| LASSERT(ldata->ld_leh); |
| |
| if (ldata->ld_leh->leh_reccount == 0) |
| ldata->ld_lee = NULL; |
| else |
| ldata->ld_lee = (struct link_ea_entry *)(ldata->ld_leh + 1); |
| } |
| |
| static inline void linkea_next_entry(struct linkea_data *ldata) |
| { |
| LASSERT(ldata); |
| LASSERT(ldata->ld_leh); |
| |
| if (ldata->ld_lee) { |
| ldata->ld_lee = (struct link_ea_entry *)((char *)ldata->ld_lee + |
| ldata->ld_reclen); |
| if ((char *)ldata->ld_lee >= ((char *)ldata->ld_leh + |
| ldata->ld_leh->leh_len)) |
| ldata->ld_lee = NULL; |
| } |
| } |