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/*
* 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;
}
}
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