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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>
*/
#include <uapi/linux/lustre/lustre_idl.h>
#include <obd.h>
#include <lustre_linkea.h>
int linkea_data_new(struct linkea_data *ldata, struct lu_buf *buf)
{
ldata->ld_buf = lu_buf_check_and_alloc(buf, PAGE_SIZE);
if (!ldata->ld_buf->lb_buf)
return -ENOMEM;
ldata->ld_leh = ldata->ld_buf->lb_buf;
ldata->ld_leh->leh_magic = LINK_EA_MAGIC;
ldata->ld_leh->leh_len = sizeof(struct link_ea_header);
ldata->ld_leh->leh_reccount = 0;
ldata->ld_leh->leh_overflow_time = 0;
ldata->ld_leh->leh_padding = 0;
return 0;
}
EXPORT_SYMBOL(linkea_data_new);
int linkea_init(struct linkea_data *ldata)
{
struct link_ea_header *leh;
LASSERT(ldata->ld_buf);
leh = ldata->ld_buf->lb_buf;
if (leh->leh_magic == __swab32(LINK_EA_MAGIC)) {
leh->leh_magic = LINK_EA_MAGIC;
leh->leh_reccount = __swab32(leh->leh_reccount);
leh->leh_len = __swab64(leh->leh_len);
leh->leh_overflow_time = __swab32(leh->leh_overflow_time);
leh->leh_padding = __swab32(leh->leh_padding);
/* individual entries are swabbed by linkea_entry_unpack() */
}
if (leh->leh_magic != LINK_EA_MAGIC)
return -EINVAL;
if (leh->leh_reccount == 0 && leh->leh_overflow_time == 0)
return -ENODATA;
ldata->ld_leh = leh;
return 0;
}
EXPORT_SYMBOL(linkea_init);
int linkea_init_with_rec(struct linkea_data *ldata)
{
int rc;
rc = linkea_init(ldata);
if (!rc && ldata->ld_leh->leh_reccount == 0)
rc = -ENODATA;
return rc;
}
EXPORT_SYMBOL(linkea_init_with_rec);
/**
* Pack a link_ea_entry.
* All elements are stored as chars to avoid alignment issues.
* Numbers are always big-endian
* \retval record length
*/
int linkea_entry_pack(struct link_ea_entry *lee, const struct lu_name *lname,
const struct lu_fid *pfid)
{
struct lu_fid tmpfid;
int reclen;
tmpfid = *pfid;
if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LINKEA_CRASH))
tmpfid.f_ver = ~0;
fid_cpu_to_be(&tmpfid, &tmpfid);
memcpy(&lee->lee_parent_fid, &tmpfid, sizeof(tmpfid));
memcpy(lee->lee_name, lname->ln_name, lname->ln_namelen);
reclen = sizeof(struct link_ea_entry) + lname->ln_namelen;
lee->lee_reclen[0] = (reclen >> 8) & 0xff;
lee->lee_reclen[1] = reclen & 0xff;
return reclen;
}
EXPORT_SYMBOL(linkea_entry_pack);
void linkea_entry_unpack(const struct link_ea_entry *lee, int *reclen,
struct lu_name *lname, struct lu_fid *pfid)
{
LASSERT(lee);
*reclen = (lee->lee_reclen[0] << 8) | lee->lee_reclen[1];
memcpy(pfid, &lee->lee_parent_fid, sizeof(*pfid));
fid_be_to_cpu(pfid, pfid);
if (lname) {
lname->ln_name = lee->lee_name;
lname->ln_namelen = *reclen - sizeof(struct link_ea_entry);
}
}
EXPORT_SYMBOL(linkea_entry_unpack);
/**
* Add a record to the end of link ea buf
**/
int linkea_add_buf(struct linkea_data *ldata, const struct lu_name *lname,
const struct lu_fid *pfid)
{
struct link_ea_header *leh = ldata->ld_leh;
int reclen;
LASSERT(leh);
if (!lname || !pfid)
return -EINVAL;
reclen = lname->ln_namelen + sizeof(struct link_ea_entry);
if (unlikely(leh->leh_len + reclen > MAX_LINKEA_SIZE)) {
/*
* Use 32-bits to save the overflow time, although it will
* shrink the ktime_get_real_seconds() returned 64-bits value
* to 32-bits value, it is still quite large and can be used
* for about 140 years. That is enough.
*/
leh->leh_overflow_time = ktime_get_real_seconds();
if (unlikely(leh->leh_overflow_time == 0))
leh->leh_overflow_time++;
CDEBUG(D_INODE, "No enough space to hold linkea entry '" DFID ": %.*s' at %u\n",
PFID(pfid), lname->ln_namelen,
lname->ln_name, leh->leh_overflow_time);
return 0;
}
if (leh->leh_len + reclen > ldata->ld_buf->lb_len) {
if (lu_buf_check_and_grow(ldata->ld_buf,
leh->leh_len + reclen) < 0)
return -ENOMEM;
leh = ldata->ld_leh = ldata->ld_buf->lb_buf;
}
ldata->ld_lee = ldata->ld_buf->lb_buf + leh->leh_len;
ldata->ld_reclen = linkea_entry_pack(ldata->ld_lee, lname, pfid);
leh->leh_len += ldata->ld_reclen;
leh->leh_reccount++;
CDEBUG(D_INODE, "New link_ea name '" DFID ":%.*s' is added\n",
PFID(pfid), lname->ln_namelen, lname->ln_name);
return 0;
}
EXPORT_SYMBOL(linkea_add_buf);
/** Del the current record from the link ea buf */
void linkea_del_buf(struct linkea_data *ldata, const struct lu_name *lname)
{
LASSERT(ldata->ld_leh && ldata->ld_lee);
LASSERT(ldata->ld_leh->leh_reccount > 0);
ldata->ld_leh->leh_reccount--;
ldata->ld_leh->leh_len -= ldata->ld_reclen;
memmove(ldata->ld_lee, (char *)ldata->ld_lee + ldata->ld_reclen,
(char *)ldata->ld_leh + ldata->ld_leh->leh_len -
(char *)ldata->ld_lee);
CDEBUG(D_INODE, "Old link_ea name '%.*s' is removed\n",
lname->ln_namelen, lname->ln_name);
if ((char *)ldata->ld_lee >= ((char *)ldata->ld_leh +
ldata->ld_leh->leh_len))
ldata->ld_lee = NULL;
}
EXPORT_SYMBOL(linkea_del_buf);
/**
* Check if such a link exists in linkEA.
*
* \param ldata link data the search to be done on
* \param lname name in the parent's directory entry pointing to this object
* \param pfid parent fid the link to be found for
*
* \retval 0 success
* \retval -ENOENT link does not exist
* \retval -ve on error
*/
int linkea_links_find(struct linkea_data *ldata, const struct lu_name *lname,
const struct lu_fid *pfid)
{
struct lu_name tmpname;
struct lu_fid tmpfid;
int count;
LASSERT(ldata->ld_leh);
/* link #0, if leh_reccount == 0 we skip the loop and return -ENOENT */
if (likely(ldata->ld_leh->leh_reccount > 0))
ldata->ld_lee = (struct link_ea_entry *)(ldata->ld_leh + 1);
for (count = 0; count < ldata->ld_leh->leh_reccount; count++) {
linkea_entry_unpack(ldata->ld_lee, &ldata->ld_reclen,
&tmpname, &tmpfid);
if (tmpname.ln_namelen == lname->ln_namelen &&
lu_fid_eq(&tmpfid, pfid) &&
(strncmp(tmpname.ln_name, lname->ln_name,
tmpname.ln_namelen) == 0))
break;
ldata->ld_lee = (struct link_ea_entry *)((char *)ldata->ld_lee +
ldata->ld_reclen);
}
if (count == ldata->ld_leh->leh_reccount) {
CDEBUG(D_INODE, "Old link_ea name '%.*s' not found\n",
lname->ln_namelen, lname->ln_name);
ldata->ld_lee = NULL;
ldata->ld_reclen = 0;
return -ENOENT;
}
return 0;
}
EXPORT_SYMBOL(linkea_links_find);
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