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/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Jeremy Allison 2006
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb_private.h"
/* Check the freelist is good and contains no loops.
Very memory intensive - only do this as a consistency
checker. Heh heh - uses an in memory tdb as the storage
for the "seen" record list. For some reason this strikes
me as extremely clever as I don't have to write another tree
data structure implementation :-).
*/
static int seen_insert(struct tdb_context *mem_tdb, tdb_off_t rec_ptr)
{
TDB_DATA key, data;
memset(&data, '\0', sizeof(data));
key.dptr = (unsigned char *)&rec_ptr;
key.dsize = sizeof(rec_ptr);
return tdb_store(mem_tdb, key, data, TDB_INSERT);
}
_PUBLIC_ int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries)
{
struct tdb_context *mem_tdb = NULL;
struct tdb_record rec;
tdb_off_t rec_ptr, last_ptr;
int ret = -1;
*pnum_entries = 0;
mem_tdb = tdb_open("flval", tdb->header.hash_size,
TDB_INTERNAL, O_RDWR, 0600);
if (!mem_tdb) {
return -1;
}
if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
tdb_close(mem_tdb);
return 0;
}
last_ptr = FREELIST_TOP;
/* Store the FREELIST_TOP record. */
if (seen_insert(mem_tdb, last_ptr) == -1) {
tdb->ecode = TDB_ERR_CORRUPT;
ret = -1;
goto fail;
}
/* read in the freelist top */
if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) {
goto fail;
}
while (rec_ptr) {
/* If we can't store this record (we've seen it
before) then the free list has a loop and must
be corrupt. */
if (seen_insert(mem_tdb, rec_ptr)) {
tdb->ecode = TDB_ERR_CORRUPT;
ret = -1;
goto fail;
}
if (tdb_rec_free_read(tdb, rec_ptr, &rec) == -1) {
goto fail;
}
/* move to the next record */
last_ptr = rec_ptr;
rec_ptr = rec.next;
*pnum_entries += 1;
}
ret = 0;
fail:
tdb_close(mem_tdb);
tdb_unlock(tdb, -1, F_WRLCK);
return ret;
}
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