[PATCH] replace tdb database by simple lockless file database

This makes the udev operation completely lockless by storing a
file for every node in /dev/.udevdb/* This solved the problem
with deadlocking concurrent udev processes waiting for each other
to release the file lock under heavy load.

1 files changed, 0 insertions, 2099 deletions

diff --git a/tdb/tdb.c b/tdb/tdb.c
deleted file mode 100644
index af475bb7ad..0000000000
--- a/tdb/tdb.c
+++ /dev/null
@@ -1,2099 +0,0 @@
- /* 
-   Unix SMB/CIFS implementation.
-   Samba database functions
-   Copyright (C) Andrew Tridgell              1999-2000
-   Copyright (C) Luke Kenneth Casson Leighton      2000
-   Copyright (C) Paul `Rusty' Russell		   2000
-   Copyright (C) Jeremy Allison			   2000-2003
-   
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
-   
-   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 for more details.
-   
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-
-/* NOTE: If you use tdbs under valgrind, and in particular if you run
- * tdbtorture, you may get spurious "uninitialized value" warnings.  I
- * think this is because valgrind doesn't understand that the mmap'd
- * area may be written to by other processes.  Memory can, from the
- * point of view of the grinded process, spontaneously become
- * initialized.
- *
- * I can think of a few solutions.  [mbp 20030311]
- *
- * 1 - Write suppressions for Valgrind so that it doesn't complain
- * about this.  Probably the most reasonable but people need to
- * remember to use them.
- *
- * 2 - Use IO not mmap when running under valgrind.  Not so nice.
- *
- * 3 - Use the special valgrind macros to mark memory as valid at the
- * right time.  Probably too hard -- the process just doesn't know.
- */ 
-
-/* udev defines */
-#define STANDALONE
-#define TDB_DEBUG
-#define HAVE_MMAP	1
-/* this should prevent deadlocks loops on corrupt databases
- * we've discovered. Most deadlocks happend by iterating over the
- * list of entries with the same hash value. */
-#define LOOP_MAX	100000
-#define TDB_LOG(x) TDB_LOG_UDEV x
-#define TDB_LOG_UDEV(tdb, level, format, arg...) info(format, ##arg)
-
-#ifdef STANDALONE
-#if HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#define _KLIBC_HAS_ARCH_SIG_ATOMIC_T
-#include <stdlib.h>
-#include <stdio.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <signal.h>
-#include "tdb.h"
-#include "spinlock.h"
-#include "../udev_lib.h"
-#include "../logging.h"
-#else
-#include "includes.h"
-#endif
-
-#define TDB_MAGIC_FOOD "TDB file\n"
-#define TDB_VERSION (0x26011967 + 6)
-#define TDB_MAGIC (0x26011999U)
-#define TDB_FREE_MAGIC (~TDB_MAGIC)
-#define TDB_DEAD_MAGIC (0xFEE1DEAD)
-#define TDB_ALIGNMENT 4
-#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
-#define DEFAULT_HASH_SIZE 131
-#define TDB_PAGE_SIZE 0x2000
-#define FREELIST_TOP (sizeof(struct tdb_header))
-#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
-#define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
-#define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
-#define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
-#define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
-
-/* NB assumes there is a local variable called "tdb" that is the
- * current context, also takes doubly-parenthesized print-style
- * argument. */
-#ifndef TDB_LOG
-#define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0)
-#endif
-
-/* lock offsets */
-#define GLOBAL_LOCK 0
-#define ACTIVE_LOCK 4
-
-#ifndef MAP_FILE
-#define MAP_FILE 0
-#endif
-
-#ifndef MAP_FAILED
-#define MAP_FAILED ((void *)-1)
-#endif
-
-/* free memory if the pointer is valid and zero the pointer */
-#ifndef SAFE_FREE
-#define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0)
-#endif
-
-#define BUCKET(hash) ((hash) % tdb->header.hash_size)
-TDB_DATA tdb_null;
-
-/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
-static TDB_CONTEXT *tdbs = NULL;
-
-static int tdb_munmap(TDB_CONTEXT *tdb)
-{
-	if (tdb->flags & TDB_INTERNAL)
-		return 0;
-
-#ifdef HAVE_MMAP
-	if (tdb->map_ptr) {
-		int ret = munmap(tdb->map_ptr, tdb->map_size);
-		if (ret != 0)
-			return ret;
-	}
-#endif
-	tdb->map_ptr = NULL;
-	return 0;
-}
-
-static void tdb_mmap(TDB_CONTEXT *tdb)
-{
-	if (tdb->flags & TDB_INTERNAL)
-		return;
-
-#ifdef HAVE_MMAP
-	if (!(tdb->flags & TDB_NOMMAP)) {
-		tdb->map_ptr = mmap(NULL, tdb->map_size, 
-				    PROT_READ|(tdb->read_only? 0:PROT_WRITE), 
-				    MAP_SHARED|MAP_FILE, tdb->fd, 0);
-
-		/*
-		 * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
-		 */
-
-		if (tdb->map_ptr == MAP_FAILED) {
-			tdb->map_ptr = NULL;
-			TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n", 
-				 tdb->map_size, strerror(errno)));
-		}
-	} else {
-		tdb->map_ptr = NULL;
-	}
-#else
-	tdb->map_ptr = NULL;
-#endif
-}
-
-/* Endian conversion: we only ever deal with 4 byte quantities */
-static void *convert(void *buf, u32 size)
-{
-	u32 i, *p = buf;
-	for (i = 0; i < size / 4; i++)
-		p[i] = TDB_BYTEREV(p[i]);
-	return buf;
-}
-#define DOCONV() (tdb->flags & TDB_CONVERT)
-#define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
-
-/* the body of the database is made of one list_struct for the free space
-   plus a separate data list for each hash value */
-struct list_struct {
-	tdb_off next; /* offset of the next record in the list */
-	tdb_len rec_len; /* total byte length of record */
-	tdb_len key_len; /* byte length of key */
-	tdb_len data_len; /* byte length of data */
-	u32 full_hash; /* the full 32 bit hash of the key */
-	u32 magic;   /* try to catch errors */
-	/* the following union is implied:
-		union {
-			char record[rec_len];
-			struct {
-				char key[key_len];
-				char data[data_len];
-			}
-			u32 totalsize; (tailer)
-		}
-	*/
-};
-
-/***************************************************************
- Allow a caller to set a "alarm" flag that tdb can check to abort
- a blocking lock on SIGALRM.
-***************************************************************/
-
-static sig_atomic_t *palarm_fired;
-
-void tdb_set_lock_alarm(sig_atomic_t *palarm)
-{
-	palarm_fired = palarm;
-}
-
-/* a byte range locking function - return 0 on success
-   this functions locks/unlocks 1 byte at the specified offset.
-
-   On error, errno is also set so that errors are passed back properly
-   through tdb_open(). */
-static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, 
-		      int rw_type, int lck_type, int probe)
-{
-	struct flock fl;
-	int ret;
-
-	if (tdb->flags & TDB_NOLOCK)
-		return 0;
-	if ((rw_type == F_WRLCK) && (tdb->read_only)) {
-		errno = EACCES;
-		return -1;
-	}
-
-	fl.l_type = rw_type;
-	fl.l_whence = SEEK_SET;
-	fl.l_start = offset;
-	fl.l_len = 1;
-	fl.l_pid = 0;
-
-	do {
-		ret = fcntl(tdb->fd,lck_type,&fl);
-		if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired)
-			break;
-	} while (ret == -1 && errno == EINTR);
-
-	if (ret == -1) {
-		if (!probe && lck_type != F_SETLK) {
-			/* Ensure error code is set for log fun to examine. */
-			if (errno == EINTR && palarm_fired && *palarm_fired)
-				tdb->ecode = TDB_ERR_LOCK_TIMEOUT;
-			else
-				tdb->ecode = TDB_ERR_LOCK;
-			TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n", 
-				 tdb->fd, offset, rw_type, lck_type));
-		}
-		/* Was it an alarm timeout ? */
-		if (errno == EINTR && palarm_fired && *palarm_fired)
-			return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT, -1);
-		/* Otherwise - generic lock error. */
-		/* errno set by fcntl */
-		return TDB_ERRCODE(TDB_ERR_LOCK, -1);
-	}
-	return 0;
-}
-
-/* lock a list in the database. list -1 is the alloc list */
-static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
-{
-	if (list < -1 || list >= (int)tdb->header.hash_size) {
-		TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n", 
-			   list, ltype));
-		return -1;
-	}
-	if (tdb->flags & TDB_NOLOCK)
-		return 0;
-
-	/* Since fcntl locks don't nest, we do a lock for the first one,
-	   and simply bump the count for future ones */
-	if (tdb->locked[list+1].count == 0) {
-		if (!tdb->read_only && tdb->header.rwlocks) {
-			if (tdb_spinlock(tdb, list, ltype)) {
-				TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n", 
-					   list, ltype));
-				return -1;
-			}
-		} else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) {
-			TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n", 
-					   list, ltype, strerror(errno)));
-			return -1;
-		}
-		tdb->locked[list+1].ltype = ltype;
-	}
-	tdb->locked[list+1].count++;
-	return 0;
-}
-
-/* unlock the database: returns void because it's too late for errors. */
-	/* changed to return int it may be interesting to know there
-	   has been an error  --simo */
-static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype)
-{
-	int ret = -1;
-
-	if (tdb->flags & TDB_NOLOCK)
-		return 0;
-
-	/* Sanity checks */
-	if (list < -1 || list >= (int)tdb->header.hash_size) {
-		TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size));
-		return ret;
-	}
-
-	if (tdb->locked[list+1].count==0) {
-		TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n"));
-		return ret;
-	}
-
-	if (tdb->locked[list+1].count == 1) {
-		/* Down to last nested lock: unlock underneath */
-		if (!tdb->read_only && tdb->header.rwlocks) {
-			ret = tdb_spinunlock(tdb, list, ltype);
-		} else {
-			ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0);
-		}
-	} else {
-		ret = 0;
-	}
-	tdb->locked[list+1].count--;
-
-	if (ret)
-		TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n")); 
-	return ret;
-}
-
-/* This is based on the hash algorithm from gdbm */
-static u32 tdb_hash(TDB_DATA *key)
-{
-	u32 value;	/* Used to compute the hash value.  */
-	u32   i;	/* Used to cycle through random values. */
-
-	/* Set the initial value from the key size. */
-	for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
-		value = (value + (key->dptr[i] << (i*5 % 24)));
-
-	return (1103515243 * value + 12345);  
-}
-
-/* check for an out of bounds access - if it is out of bounds then
-   see if the database has been expanded by someone else and expand
-   if necessary 
-   note that "len" is the minimum length needed for the db
-*/
-static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe)
-{
-	struct stat st;
-	if (len <= tdb->map_size)
-		return 0;
-	if (tdb->flags & TDB_INTERNAL) {
-		if (!probe) {
-			/* Ensure ecode is set for log fn. */
-			tdb->ecode = TDB_ERR_IO;
-			TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n",
-				 (int)len, (int)tdb->map_size));
-		}
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-	}
-
-	if (fstat(tdb->fd, &st) == -1)
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-
-	if (st.st_size < (size_t)len) {
-		if (!probe) {
-			/* Ensure ecode is set for log fn. */
-			tdb->ecode = TDB_ERR_IO;
-			TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n",
-				 (int)len, (int)st.st_size));
-		}
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-	}
-
-	/* Unmap, update size, remap */
-	if (tdb_munmap(tdb) == -1)
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-	tdb->map_size = st.st_size;
-	tdb_mmap(tdb);
-	return 0;
-}
-
-/* write a lump of data at a specified offset */
-static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len)
-{
-	if (tdb_oob(tdb, off + len, 0) != 0)
-		return -1;
-
-	if (tdb->map_ptr)
-		memcpy(off + (char *)tdb->map_ptr, buf, len);
-#ifdef HAVE_PWRITE
-	else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) {
-#else
-	else if (lseek(tdb->fd, off, SEEK_SET) != off
-		 || write(tdb->fd, buf, len) != (ssize_t)len) {
-#endif
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_IO;
-		TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n",
-			   off, len, strerror(errno)));
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-	}
-	return 0;
-}
-
-/* read a lump of data at a specified offset, maybe convert */
-static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv)
-{
-	if (tdb_oob(tdb, off + len, 0) != 0)
-		return -1;
-
-	if (tdb->map_ptr)
-		memcpy(buf, off + (char *)tdb->map_ptr, len);
-#ifdef HAVE_PREAD
-	else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) {
-#else
-	else if (lseek(tdb->fd, off, SEEK_SET) != off
-		 || read(tdb->fd, buf, len) != (ssize_t)len) {
-#endif
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_IO;
-		TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n",
-			   off, len, strerror(errno)));
-		return TDB_ERRCODE(TDB_ERR_IO, -1);
-	}
-	if (cv)
-		convert(buf, len);
-	return 0;
-}
-
-/* read a lump of data, allocating the space for it */
-static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len)
-{
-	char *buf;
-
-	if (!(buf = malloc(len))) {
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_OOM;
-		TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
-			   len, strerror(errno)));
-		return TDB_ERRCODE(TDB_ERR_OOM, buf);
-	}
-	if (tdb_read(tdb, offset, buf, len, 0) == -1) {
-		SAFE_FREE(buf);
-		return NULL;
-	}
-	return buf;
-}
-
-/* read/write a tdb_off */
-static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
-{
-	return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV());
-}
-static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
-{
-	tdb_off off = *d;
-	return tdb_write(tdb, offset, CONVERT(off), sizeof(*d));
-}
-
-/* read/write a record */
-static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
-	if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1)
-		return -1;
-	if (TDB_BAD_MAGIC(rec)) {
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_CORRUPT;
-		TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
-		return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-	}
-	return tdb_oob(tdb, rec->next+sizeof(*rec), 0);
-}
-static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
-	struct list_struct r = *rec;
-	return tdb_write(tdb, offset, CONVERT(r), sizeof(r));
-}
-
-/* read a freelist record and check for simple errors */
-static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
-{
-	if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
-		return -1;
-
-	if (rec->magic == TDB_MAGIC) {
-		/* this happens when a app is showdown while deleting a record - we should
-		   not completely fail when this happens */
-		TDB_LOG((tdb, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n", 
-			 rec->magic, off));
-		rec->magic = TDB_FREE_MAGIC;
-		if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1)
-			return -1;
-	}
-
-	if (rec->magic != TDB_FREE_MAGIC) {
-		/* Ensure ecode is set for log fn. */
-		tdb->ecode = TDB_ERR_CORRUPT;
-		TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n", 
-			   rec->magic, off));
-		return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-	}
-	if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
-		return -1;
-	return 0;
-}
-
-/* update a record tailer (must hold allocation lock) */
-static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset,
-			 const struct list_struct *rec)
-{
-	tdb_off totalsize;
-
-	/* Offset of tailer from record header */
-	totalsize = sizeof(*rec) + rec->rec_len;
-	return ofs_write(tdb, offset + totalsize - sizeof(tdb_off),
-			 &totalsize);
-}
-
-static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset)
-{
-	struct list_struct rec;
-	tdb_off tailer_ofs, tailer;
-
-	if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
-		printf("ERROR: failed to read record at %u\n", offset);
-		return 0;
-	}
-
-	printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
-	       offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic);
-
-	tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off);
-	if (ofs_read(tdb, tailer_ofs, &tailer) == -1) {
-		printf("ERROR: failed to read tailer at %u\n", tailer_ofs);
-		return rec.next;
-	}
-
-	if (tailer != rec.rec_len + sizeof(rec)) {
-		printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
-				(unsigned)tailer, (unsigned)(rec.rec_len + sizeof(rec)));
-	}
-	return rec.next;
-}
-
-static int tdb_dump_chain(TDB_CONTEXT *tdb, int i)
-{
-	tdb_off rec_ptr, top;
-
-	top = TDB_HASH_TOP(i);
-
-	if (tdb_lock(tdb, i, F_WRLCK) != 0)
-		return -1;
-
-	if (ofs_read(tdb, top, &rec_ptr) == -1)
-		return tdb_unlock(tdb, i, F_WRLCK);
-
-	if (rec_ptr)
-		printf("hash=%d\n", i);
-
-	while (rec_ptr) {
-		rec_ptr = tdb_dump_record(tdb, rec_ptr);
-	}
-
-	return tdb_unlock(tdb, i, F_WRLCK);
-}
-
-void tdb_dump_all(TDB_CONTEXT *tdb)
-{
-	int i;
-	for (i=0;i<tdb->header.hash_size;i++) {
-		tdb_dump_chain(tdb, i);
-	}
-	printf("freelist:\n");
-	tdb_dump_chain(tdb, -1);
-}
-
-int tdb_printfreelist(TDB_CONTEXT *tdb)
-{
-	int ret;
-	long total_free = 0;
-	tdb_off offset, rec_ptr;
-	struct list_struct rec;
-
-	if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0)
-		return ret;
-
-	offset = FREELIST_TOP;
-
-	/* read in the freelist top */
-	if (ofs_read(tdb, offset, &rec_ptr) == -1) {
-		tdb_unlock(tdb, -1, F_WRLCK);
-		return 0;
-	}
-
-	printf("freelist top=[0x%08x]\n", rec_ptr );
-	while (rec_ptr) {
-		if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
-			tdb_unlock(tdb, -1, F_WRLCK);
-			return -1;
-		}
-
-		if (rec.magic != TDB_FREE_MAGIC) {
-			printf("bad magic 0x%08x in free list\n", rec.magic);
-			tdb_unlock(tdb, -1, F_WRLCK);
-			return -1;
-		}
-
-		printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec.next, rec.rec_len, rec.rec_len );
-		total_free += rec.rec_len;
-
-		/* move to the next record */
-		rec_ptr = rec.next;
-	}
-	printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, 
-               (int)total_free);
-
-	return tdb_unlock(tdb, -1, F_WRLCK);
-}
-
-/* Remove an element from the freelist.  Must have alloc lock. */
-static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
-{
-	tdb_off last_ptr, i;
-	int maxloop;
-
-	/* read in the freelist top */
-	maxloop = LOOP_MAX;
-	last_ptr = FREELIST_TOP;
-	while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
-		if (i == off) {
-			/* We've found it! */
-			return ofs_write(tdb, last_ptr, &next);
-		}
-		/* Follow chain (next offset is at start of record) */
-		last_ptr = i;
-
-		maxloop--;
-		if (maxloop == 0) {
-			TDB_LOG((tdb, 0, "remove_from_freelist: maxloop reached; corrupt database!\n"));
-			return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-		}
-	}
-	TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
-	return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-}
-
-/* Add an element into the freelist. Merge adjacent records if
-   neccessary. */
-static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
-{
-	tdb_off right, left;
-
-	/* Allocation and tailer lock */
-	if (tdb_lock(tdb, -1, F_WRLCK) != 0)
-		return -1;
-
-	/* set an initial tailer, so if we fail we don't leave a bogus record */
-	if (update_tailer(tdb, offset, rec) != 0) {
-		TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n"));
-		goto fail;
-	}
-
-	/* Look right first (I'm an Australian, dammit) */
-	right = offset + sizeof(*rec) + rec->rec_len;
-	if (right + sizeof(*rec) <= tdb->map_size) {
-		struct list_struct r;
-
-		if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
-			TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right));
-			goto left;
-		}
-
-		/* If it's free, expand to include it. */
-		if (r.magic == TDB_FREE_MAGIC) {
-			if (remove_from_freelist(tdb, right, r.next) == -1) {
-				TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right));
-				goto left;
-			}
-			rec->rec_len += sizeof(r) + r.rec_len;
-		}
-	}
-
-left:
-	/* Look left */
-	left = offset - sizeof(tdb_off);
-	if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) {
-		struct list_struct l;
-		tdb_off leftsize;
-
-		/* Read in tailer and jump back to header */
-		if (ofs_read(tdb, left, &leftsize) == -1) {
-			TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left));
-			goto update;
-		}
-		left = offset - leftsize;
-
-		/* Now read in record */
-		if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
-			TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
-			goto update;
-		}
-
-		/* If it's free, expand to include it. */
-		if (l.magic == TDB_FREE_MAGIC) {
-			if (remove_from_freelist(tdb, left, l.next) == -1) {
-				TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left));
-				goto update;
-			} else {
-				offset = left;
-				rec->rec_len += leftsize;
-			}
-		}
-	}
-
-update:
-	if (update_tailer(tdb, offset, rec) == -1) {
-		TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset));
-		goto fail;
-	}
-
-	/* Now, prepend to free list */
-	rec->magic = TDB_FREE_MAGIC;
-
-	if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
-	    rec_write(tdb, offset, rec) == -1 ||
-	    ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
-		TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset));
-		goto fail;
-	}
-
-	/* And we're done. */
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
-
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return -1;
-}
-
-
-/* expand a file.  we prefer to use ftruncate, as that is what posix
-  says to use for mmap expansion */
-static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
-{
-	char buf[1024];
-#if HAVE_FTRUNCATE_EXTEND
-	if (ftruncate(tdb->fd, size+addition) != 0) {
-		TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n", 
-			   size+addition, strerror(errno)));
-		return -1;
-	}
-#else
-	char b = 0;
-
-#ifdef HAVE_PWRITE
-	if (pwrite(tdb->fd,  &b, 1, (size+addition) - 1) != 1) {
-#else
-	if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 || 
-	    write(tdb->fd, &b, 1) != 1) {
-#endif
-		TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n", 
-			   size+addition, strerror(errno)));
-		return -1;
-	}
-#endif
-
-	/* now fill the file with something. This ensures that the file isn't sparse, which would be
-	   very bad if we ran out of disk. This must be done with write, not via mmap */
-	memset(buf, 0x42, sizeof(buf));
-	while (addition) {
-		int n = addition>sizeof(buf)?sizeof(buf):addition;
-#ifdef HAVE_PWRITE
-		int ret = pwrite(tdb->fd, buf, n, size);
-#else
-		int ret;
-		if (lseek(tdb->fd, size, SEEK_SET) != size)
-			return -1;
-		ret = write(tdb->fd, buf, n);
-#endif
-		if (ret != n) {
-			TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n", 
-				   n, strerror(errno)));
-			return -1;
-		}
-		addition -= n;
-		size += n;
-	}
-	return 0;
-}
-
-
-/* expand the database at least size bytes by expanding the underlying
-   file and doing the mmap again if necessary */
-static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
-{
-	struct list_struct rec;
-	tdb_off offset;
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
-		TDB_LOG((tdb, 0, "lock failed in tdb_expand\n"));
-		return -1;
-	}
-
-	/* must know about any previous expansions by another process */
-	tdb_oob(tdb, tdb->map_size + 1, 1);
-
-	/* always make room for at least 10 more records, and round
-           the database up to a multiple of TDB_PAGE_SIZE */
-	size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size;
-
-	if (!(tdb->flags & TDB_INTERNAL))
-		tdb_munmap(tdb);
-
-	/*
-	 * We must ensure the file is unmapped before doing this
-	 * to ensure consistency with systems like OpenBSD where
-	 * writes and mmaps are not consistent.
-	 */
-
-	/* expand the file itself */
-	if (!(tdb->flags & TDB_INTERNAL)) {
-		if (expand_file(tdb, tdb->map_size, size) != 0)
-			goto fail;
-	}
-
-	tdb->map_size += size;
-
-	if (tdb->flags & TDB_INTERNAL)
-		tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size);
-	else {
-		/*
-		 * We must ensure the file is remapped before adding the space
-		 * to ensure consistency with systems like OpenBSD where
-		 * writes and mmaps are not consistent.
-		 */
-
-		/* We're ok if the mmap fails as we'll fallback to read/write */
-		tdb_mmap(tdb);
-	}
-
-	/* form a new freelist record */
-	memset(&rec,'\0',sizeof(rec));
-	rec.rec_len = size - sizeof(rec);
-
-	/* link it into the free list */
-	offset = tdb->map_size - size;
-	if (tdb_free(tdb, offset, &rec) == -1)
-		goto fail;
-
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return -1;
-}
-
-/* allocate some space from the free list. The offset returned points
-   to a unconnected list_struct within the database with room for at
-   least length bytes of total data
-
-   0 is returned if the space could not be allocated
- */
-static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
-			    struct list_struct *rec)
-{
-	tdb_off rec_ptr, last_ptr, newrec_ptr;
-	struct list_struct newrec;
-	int maxloop;
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1)
-		return 0;
-
-	/* Extra bytes required for tailer */
-	length += sizeof(tdb_off);
-
- again:
-	last_ptr = FREELIST_TOP;
-
-	/* read in the freelist top */
-	if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
-		goto fail;
-
-	/* keep looking until we find a freelist record big enough */
-	maxloop = LOOP_MAX;
-	while (rec_ptr) {
-		if (rec_free_read(tdb, rec_ptr, rec) == -1)
-			goto fail;
-
-		if (rec->rec_len >= length) {
-			/* found it - now possibly split it up  */
-			if (rec->rec_len > length + MIN_REC_SIZE) {
-				/* Length of left piece */
-				length = TDB_ALIGN(length, TDB_ALIGNMENT);
-
-				/* Right piece to go on free list */
-				newrec.rec_len = rec->rec_len
-					- (sizeof(*rec) + length);
-				newrec_ptr = rec_ptr + sizeof(*rec) + length;
-
-				/* And left record is shortened */
-				rec->rec_len = length;
-			} else
-				newrec_ptr = 0;
-
-			/* Remove allocated record from the free list */
-			if (ofs_write(tdb, last_ptr, &rec->next) == -1)
-				goto fail;
-
-			/* Update header: do this before we drop alloc
-                           lock, otherwise tdb_free() might try to
-                           merge with us, thinking we're free.
-                           (Thanks Jeremy Allison). */
-			rec->magic = TDB_MAGIC;
-			if (rec_write(tdb, rec_ptr, rec) == -1)
-				goto fail;
-
-			/* Did we create new block? */
-			if (newrec_ptr) {
-				/* Update allocated record tailer (we
-                                   shortened it). */
-				if (update_tailer(tdb, rec_ptr, rec) == -1)
-					goto fail;
-
-				/* Free new record */
-				if (tdb_free(tdb, newrec_ptr, &newrec) == -1)
-					goto fail;
-			}
-
-			/* all done - return the new record offset */
-			tdb_unlock(tdb, -1, F_WRLCK);
-			return rec_ptr;
-		}
-		/* move to the next record */
-		last_ptr = rec_ptr;
-		rec_ptr = rec->next;
-
-		maxloop--;
-		if (maxloop == 0) {
-			TDB_LOG((tdb, 0, "tdb_allocate: maxloop reached; corrupt database!\n"));
-			return TDB_ERRCODE(TDB_ERR_CORRUPT, 0);
-		}
-	}
-	/* we didn't find enough space. See if we can expand the
-	   database and if we can then try again */
-	if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
-		goto again;
- fail:
-	tdb_unlock(tdb, -1, F_WRLCK);
-	return 0;
-}
-
-/* initialise a new database with a specified hash size */
-static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
-{
-	struct tdb_header *newdb;
-	int size, ret = -1;
-
-	/* We make it up in memory, then write it out if not internal */
-	size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off);
-	if (!(newdb = calloc(size, 1)))
-		return TDB_ERRCODE(TDB_ERR_OOM, -1);
-
-	/* Fill in the header */
-	newdb->version = TDB_VERSION;
-	newdb->hash_size = hash_size;
-#ifdef USE_SPINLOCKS
-	newdb->rwlocks = size;
-#endif
-	if (tdb->flags & TDB_INTERNAL) {
-		tdb->map_size = size;
-		tdb->map_ptr = (char *)newdb;
-		memcpy(&tdb->header, newdb, sizeof(tdb->header));
-		/* Convert the `ondisk' version if asked. */
-		CONVERT(*newdb);
-		return 0;
-	}
-	if (lseek(tdb->fd, 0, SEEK_SET) == -1)
-		goto fail;
-
-	if (ftruncate(tdb->fd, 0) == -1)
-		goto fail;
-
-	/* This creates an endian-converted header, as if read from disk */
-	CONVERT(*newdb);
-	memcpy(&tdb->header, newdb, sizeof(tdb->header));
-	/* Don't endian-convert the magic food! */
-	memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
-	if (write(tdb->fd, newdb, size) != size)
-		ret = -1;
-	else
-		ret = tdb_create_rwlocks(tdb->fd, hash_size);
-
-  fail:
-	SAFE_FREE(newdb);
-	return ret;
-}
-
-/* Returns 0 on fail.  On success, return offset of record, and fills
-   in rec */
-static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
-			struct list_struct *r)
-{
-	tdb_off rec_ptr;
-	int maxloop;
-
-	/* read in the hash top */
-	if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
-		return 0;
-
-	/* keep looking until we find the right record */
-	maxloop = LOOP_MAX;
-	while (rec_ptr) {
-		if (rec_read(tdb, rec_ptr, r) == -1)
-			return 0;
-
-		if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) {
-			char *k;
-			/* a very likely hit - read the key */
-			k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r), 
-					   r->key_len);
-			if (!k)
-				return 0;
-
-			if (memcmp(key.dptr, k, key.dsize) == 0) {
-				SAFE_FREE(k);
-				return rec_ptr;
-			}
-			SAFE_FREE(k);
-		}
-		rec_ptr = r->next;
-
-		maxloop--;
-		if (maxloop == 0) {
-			TDB_LOG((tdb, 0, "tdb_find maxloop reached; corrupt database!\n"));
-			return TDB_ERRCODE(TDB_ERR_CORRUPT, 0);
-		}
-	}
-	return TDB_ERRCODE(TDB_ERR_NOEXIST, 0);
-}
-
-/* If they do lockkeys, check that this hash is one they locked */
-static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash)
-{
-	u32 i;
-	if (!tdb->lockedkeys)
-		return 1;
-	for (i = 0; i < tdb->lockedkeys[0]; i++)
-		if (tdb->lockedkeys[i+1] == hash)
-			return 1;
-	return TDB_ERRCODE(TDB_ERR_NOLOCK, 0);
-}
-
-/* As tdb_find, but if you succeed, keep the lock */
-static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype,
-			     struct list_struct *rec)
-{
-	u32 hash, rec_ptr;
-
-	hash = tdb_hash(&key);
-	if (!tdb_keylocked(tdb, hash))
-		return 0;
-	if (tdb_lock(tdb, BUCKET(hash), locktype) == -1)
-		return 0;
-	if (!(rec_ptr = tdb_find(tdb, key, hash, rec)))
-		tdb_unlock(tdb, BUCKET(hash), locktype);
-	return rec_ptr;
-}
-
-enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb)
-{
-	return tdb->ecode;
-}
-
-static struct tdb_errname {
-	enum TDB_ERROR ecode; const char *estring;
-} emap[] = { {TDB_SUCCESS, "Success"},
-	     {TDB_ERR_CORRUPT, "Corrupt database"},
-	     {TDB_ERR_IO, "IO Error"},
-	     {TDB_ERR_LOCK, "Locking error"},
-	     {TDB_ERR_OOM, "Out of memory"},
-	     {TDB_ERR_EXISTS, "Record exists"},
-	     {TDB_ERR_NOLOCK, "Lock exists on other keys"},
-	     {TDB_ERR_NOEXIST, "Record does not exist"} };
-
-/* Error string for the last tdb error */
-const char *tdb_errorstr(TDB_CONTEXT *tdb)
-{
-	u32 i;
-	for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++)
-		if (tdb->ecode == emap[i].ecode)
-			return emap[i].estring;
-	return "Invalid error code";
-}
-
-/* update an entry in place - this only works if the new data size
-   is <= the old data size and the key exists.
-   on failure return -1.
-*/
-
-static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf)
-{
-	struct list_struct rec;
-	tdb_off rec_ptr;
-
-	/* find entry */
-	if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec)))
-		return -1;
-
-	/* must be long enough key, data and tailer */
-	if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) {
-		tdb->ecode = TDB_SUCCESS; /* Not really an error */
-		return -1;
-	}
-
-	if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
-		      dbuf.dptr, dbuf.dsize) == -1)
-		return -1;
-
-	if (dbuf.dsize != rec.data_len) {
-		/* update size */
-		rec.data_len = dbuf.dsize;
-		return rec_write(tdb, rec_ptr, &rec);
-	}
- 
-	return 0;
-}
-
-/* find an entry in the database given a key */
-/* If an entry doesn't exist tdb_err will be set to
- * TDB_ERR_NOEXIST. If a key has no data attached
- * tdb_err will not be set. Both will return a
- * zero pptr and zero dsize.
- */
-
-TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	tdb_off rec_ptr;
-	struct list_struct rec;
-	TDB_DATA ret;
-
-	/* find which hash bucket it is in */
-	if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec)))
-		return tdb_null;
-
-	if (rec.data_len)
-		ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
-					  rec.data_len);
-	else
-		ret.dptr = NULL;
-	ret.dsize = rec.data_len;
-	tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
-	return ret;
-}
-
-/* check if an entry in the database exists 
-
-   note that 1 is returned if the key is found and 0 is returned if not found
-   this doesn't match the conventions in the rest of this module, but is
-   compatible with gdbm
-*/
-int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	struct list_struct rec;
-	
-	if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0)
-		return 0;
-	tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
-	return 1;
-}
-
-/* record lock stops delete underneath */
-static int lock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
-	return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0;
-}
-/*
-  Write locks override our own fcntl readlocks, so check it here.
-  Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
-  an error to fail to get the lock here.
-*/
- 
-static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
-	struct tdb_traverse_lock *i;
-	for (i = &tdb->travlocks; i; i = i->next)
-		if (i->off == off)
-			return -1;
-	return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1);
-}
-
-/*
-  Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
-  an error to fail to get the lock here.
-*/
-
-static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
-	return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0);
-}
-/* fcntl locks don't stack: avoid unlocking someone else's */
-static int unlock_record(TDB_CONTEXT *tdb, tdb_off off)
-{
-	struct tdb_traverse_lock *i;
-	u32 count = 0;
-
-	if (off == 0)
-		return 0;
-	for (i = &tdb->travlocks; i; i = i->next)
-		if (i->off == off)
-			count++;
-	return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0);
-}
-
-/* actually delete an entry in the database given the offset */
-static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
-{
-	tdb_off last_ptr, i;
-	struct list_struct lastrec;
-	int maxloop;
-
-	if (tdb->read_only) return -1;
-
-	if (write_lock_record(tdb, rec_ptr) == -1) {
-		/* Someone traversing here: mark it as dead */
-		rec->magic = TDB_DEAD_MAGIC;
-		return rec_write(tdb, rec_ptr, rec);
-	}
-	if (write_unlock_record(tdb, rec_ptr) != 0)
-		return -1;
-
-	/* find previous record in hash chain */
-	if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
-		return -1;
-
-	maxloop = LOOP_MAX;
-	for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) {
-		if (rec_read(tdb, i, &lastrec) == -1)
-			return -1;
-
-		maxloop--;
-		if (maxloop == 0) {
-			TDB_LOG((tdb, 0, "(tdb)do_delete: maxloop reached; corrupt database!\n"));
-			return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
-		}
-	}
-
-	/* unlink it: next ptr is at start of record. */
-	if (last_ptr == 0)
-		last_ptr = TDB_HASH_TOP(rec->full_hash);
-	if (ofs_write(tdb, last_ptr, &rec->next) == -1)
-		return -1;
-
-	/* recover the space */
-	if (tdb_free(tdb, rec_ptr, rec) == -1)
-		return -1;
-	return 0;
-}
-
-/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
-static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
-			 struct list_struct *rec)
-{
-	int want_next = (tlock->off != 0);
-
-	/* No traversal allows if you've called tdb_lockkeys() */
-	if (tdb->lockedkeys)
-		return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
-
-	/* Lock each chain from the start one. */
-	for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
-		if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1)
-			return -1;
-
-		/* No previous record?  Start at top of chain. */
-		if (!tlock->off) {
-			if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash),
-				     &tlock->off) == -1)
-				goto fail;
-		} else {
-			/* Otherwise unlock the previous record. */
-			if (unlock_record(tdb, tlock->off) != 0)
-				goto fail;
-		}
-
-		if (want_next) {
-			/* We have offset of old record: grab next */
-			if (rec_read(tdb, tlock->off, rec) == -1)
-				goto fail;
-			tlock->off = rec->next;
-		}
-
-		/* Iterate through chain */
-		while( tlock->off) {
-			tdb_off current;
-			if (rec_read(tdb, tlock->off, rec) == -1)
-				goto fail;
-			if (!TDB_DEAD(rec)) {
-				/* Woohoo: we found one! */
-				if (lock_record(tdb, tlock->off) != 0)
-					goto fail;
-				return tlock->off;
-			}
-			/* Try to clean dead ones from old traverses */
-			current = tlock->off;
-			tlock->off = rec->next;
-			if (!tdb->read_only && 
-			    do_delete(tdb, current, rec) != 0)
-				goto fail;
-		}
-		tdb_unlock(tdb, tlock->hash, F_WRLCK);
-		want_next = 0;
-	}
-	/* We finished iteration without finding anything */
-	return TDB_ERRCODE(TDB_SUCCESS, 0);
-
- fail:
-	tlock->off = 0;
-	if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0)
-		TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n"));
-	return -1;
-}
-
-/* traverse the entire database - calling fn(tdb, key, data) on each element.
-   return -1 on error or the record count traversed
-   if fn is NULL then it is not called
-   a non-zero return value from fn() indicates that the traversal should stop
-  */
-int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state)
-{
-	TDB_DATA key, dbuf;
-	struct list_struct rec;
-	struct tdb_traverse_lock tl = { NULL, 0, 0 };
-	int ret, count = 0;
-
-	/* This was in the initializaton, above, but the IRIX compiler
-	 * did not like it.  crh
-	 */
-	tl.next = tdb->travlocks.next;
-
-	/* fcntl locks don't stack: beware traverse inside traverse */
-	tdb->travlocks.next = &tl;
-
-	/* tdb_next_lock places locks on the record returned, and its chain */
-	while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) {
-		count++;
-		/* now read the full record */
-		key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec), 
-					  rec.key_len + rec.data_len);
-		if (!key.dptr) {
-			ret = -1;
-			if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0)
-				goto out;
-			if (unlock_record(tdb, tl.off) != 0)
-				TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
-			goto out;
-		}
-		key.dsize = rec.key_len;
-		dbuf.dptr = key.dptr + rec.key_len;
-		dbuf.dsize = rec.data_len;
-
-		/* Drop chain lock, call out */
-		if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) {
-			ret = -1;
-			goto out;
-		}
-		if (fn && fn(tdb, key, dbuf, state)) {
-			/* They want us to terminate traversal */
-			ret = count;
-			if (unlock_record(tdb, tl.off) != 0) {
-				TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));;
-				ret = -1;
-			}
-			tdb->travlocks.next = tl.next;
-			SAFE_FREE(key.dptr);
-			return count;
-		}
-		SAFE_FREE(key.dptr);
-	}
-out:
-	tdb->travlocks.next = tl.next;
-	if (ret < 0)
-		return -1;
-	else
-		return count;
-}
-
-/* find the first entry in the database and return its key */
-TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
-{
-	TDB_DATA key;
-	struct list_struct rec;
-
-	/* release any old lock */
-	if (unlock_record(tdb, tdb->travlocks.off) != 0)
-		return tdb_null;
-	tdb->travlocks.off = tdb->travlocks.hash = 0;
-
-	if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
-		return tdb_null;
-	/* now read the key */
-	key.dsize = rec.key_len;
-	key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
-	if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0)
-		TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
-	return key;
-}
-
-/* find the next entry in the database, returning its key */
-TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey)
-{
-	u32 oldhash;
-	TDB_DATA key = tdb_null;
-	struct list_struct rec;
-	char *k = NULL;
-
-	/* Is locked key the old key?  If so, traverse will be reliable. */
-	if (tdb->travlocks.off) {
-		if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK))
-			return tdb_null;
-		if (rec_read(tdb, tdb->travlocks.off, &rec) == -1
-		    || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
-					    rec.key_len))
-		    || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
-			/* No, it wasn't: unlock it and start from scratch */
-			if (unlock_record(tdb, tdb->travlocks.off) != 0)
-				return tdb_null;
-			if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
-				return tdb_null;
-			tdb->travlocks.off = 0;
-		}
-
-		SAFE_FREE(k);
-	}
-
-	if (!tdb->travlocks.off) {
-		/* No previous element: do normal find, and lock record */
-		tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec);
-		if (!tdb->travlocks.off)
-			return tdb_null;
-		tdb->travlocks.hash = BUCKET(rec.full_hash);
-		if (lock_record(tdb, tdb->travlocks.off) != 0) {
-			TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno)));
-			return tdb_null;
-		}
-	}
-	oldhash = tdb->travlocks.hash;
-
-	/* Grab next record: locks chain and returned record,
-	   unlocks old record */
-	if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
-		key.dsize = rec.key_len;
-		key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
-					  key.dsize);
-		/* Unlock the chain of this new record */
-		if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0)
-			TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
-	}
-	/* Unlock the chain of old record */
-	if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0)
-		TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
-	return key;
-}
-
-/* delete an entry in the database given a key */
-int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	tdb_off rec_ptr;
-	struct list_struct rec;
-	int ret;
-
-	if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec)))
-		return -1;
-	ret = do_delete(tdb, rec_ptr, &rec);
-	if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0)
-		TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n"));
-	return ret;
-}
-
-/* store an element in the database, replacing any existing element
-   with the same key 
-
-   return 0 on success, -1 on failure
-*/
-int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
-{
-	struct list_struct rec;
-	u32 hash;
-	tdb_off rec_ptr;
-	char *p = NULL;
-	int ret = 0;
-
-	/* find which hash bucket it is in */
-	hash = tdb_hash(&key);
-	if (!tdb_keylocked(tdb, hash))
-		return -1;
-	if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
-		return -1;
-
-	/* check for it existing, on insert. */
-	if (flag == TDB_INSERT) {
-		if (tdb_exists(tdb, key)) {
-			tdb->ecode = TDB_ERR_EXISTS;
-			goto fail;
-		}
-	} else {
-		/* first try in-place update, on modify or replace. */
-		if (tdb_update(tdb, key, dbuf) == 0)
-			goto out;
-		if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST)
-			goto fail;
-	}
-	/* reset the error code potentially set by the tdb_update() */
-	tdb->ecode = TDB_SUCCESS;
-
-	/* delete any existing record - if it doesn't exist we don't
-           care.  Doing this first reduces fragmentation, and avoids
-           coalescing with `allocated' block before it's updated. */
-	if (flag != TDB_INSERT)
-		tdb_delete(tdb, key);
-
-	/* Copy key+value *before* allocating free space in case malloc
-	   fails and we are left with a dead spot in the tdb. */
-
-	if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
-		tdb->ecode = TDB_ERR_OOM;
-		goto fail;
-	}
-
-	memcpy(p, key.dptr, key.dsize);
-	if (dbuf.dsize)
-		memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
-
-	/* now we're into insert / modify / replace of a record which
-	 * we know could not be optimised by an in-place store (for
-	 * various reasons).  */
-	if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec)))
-		goto fail;
-
-	/* Read hash top into next ptr */
-	if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
-		goto fail;
-
-	rec.key_len = key.dsize;
-	rec.data_len = dbuf.dsize;
-	rec.full_hash = hash;
-	rec.magic = TDB_MAGIC;
-
-	/* write out and point the top of the hash chain at it */
-	if (rec_write(tdb, rec_ptr, &rec) == -1
-	    || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
-	    || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
-		/* Need to tdb_unallocate() here */
-		goto fail;
-	}
- out:
-	SAFE_FREE(p); 
-	tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
-	return ret;
-fail:
-	ret = -1;
-	goto out;
-}
-
-/* Attempt to append data to an entry in place - this only works if the new data size
-   is <= the old data size and the key exists.
-   on failure return -1. Record must be locked before calling.
-*/
-static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
-{
-	struct list_struct rec;
-	tdb_off rec_ptr;
-
-	/* find entry */
-	if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec)))
-		return -1;
-
-	/* Append of 0 is always ok. */
-	if (new_dbuf.dsize == 0)
-		return 0;
-
-	/* must be long enough for key, old data + new data and tailer */
-	if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) {
-		/* No room. */
-		tdb->ecode = TDB_SUCCESS; /* Not really an error */
-		return -1;
-	}
-
-	if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len,
-		      new_dbuf.dptr, new_dbuf.dsize) == -1)
-		return -1;
-
-	/* update size */
-	rec.data_len += new_dbuf.dsize;
-	return rec_write(tdb, rec_ptr, &rec);
-}
-
-/* Append to an entry. Create if not exist. */
-
-int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf)
-{
-	struct list_struct rec;
-	u32 hash;
-	tdb_off rec_ptr;
-	char *p = NULL;
-	int ret = 0;
-	size_t new_data_size = 0;
-
-	/* find which hash bucket it is in */
-	hash = tdb_hash(&key);
-	if (!tdb_keylocked(tdb, hash))
-		return -1;
-	if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
-		return -1;
-
-	/* first try in-place. */
-	if (tdb_append_inplace(tdb, key, new_dbuf) == 0)
-		goto out;
-
-	/* reset the error code potentially set by the tdb_append_inplace() */
-	tdb->ecode = TDB_SUCCESS;
-
-	/* find entry */
-	if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) {
-		if (tdb->ecode != TDB_ERR_NOEXIST)
-			goto fail;
-
-		/* Not found - create. */
-
-		ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT);
-		goto out;
-	}
-
-	new_data_size = rec.data_len + new_dbuf.dsize;
-
-	/* Copy key+old_value+value *before* allocating free space in case malloc
-	   fails and we are left with a dead spot in the tdb. */
-
-	if (!(p = (char *)malloc(key.dsize + new_data_size))) {
-		tdb->ecode = TDB_ERR_OOM;
-		goto fail;
-	}
-
-	/* Copy the key in place. */
-	memcpy(p, key.dptr, key.dsize);
-
-	/* Now read the old data into place. */
-	if (rec.data_len &&
-		tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1)
-			goto fail;
-
-	/* Finally append the new data. */
-	if (new_dbuf.dsize)
-		memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize);
-
-	/* delete any existing record - if it doesn't exist we don't
-           care.  Doing this first reduces fragmentation, and avoids
-           coalescing with `allocated' block before it's updated. */
-
-	tdb_delete(tdb, key);
-
-	if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec)))
-		goto fail;
-
-	/* Read hash top into next ptr */
-	if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
-		goto fail;
-
-	rec.key_len = key.dsize;
-	rec.data_len = new_data_size;
-	rec.full_hash = hash;
-	rec.magic = TDB_MAGIC;
-
-	/* write out and point the top of the hash chain at it */
-	if (rec_write(tdb, rec_ptr, &rec) == -1
-	    || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1
-	    || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
-		/* Need to tdb_unallocate() here */
-		goto fail;
-	}
-
- out:
-	SAFE_FREE(p); 
-	tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
-	return ret;
-
-fail:
-	ret = -1;
-	goto out;
-}
-
-static int tdb_already_open(dev_t device,
-			    ino_t ino)
-{
-	TDB_CONTEXT *i;
-	
-	for (i = tdbs; i; i = i->next) {
-		if (i->device == device && i->inode == ino) {
-			return 1;
-		}
-	}
-
-	return 0;
-}
-
-/* open the database, creating it if necessary 
-
-   The open_flags and mode are passed straight to the open call on the
-   database file. A flags value of O_WRONLY is invalid. The hash size
-   is advisory, use zero for a default value.
-
-   Return is NULL on error, in which case errno is also set.  Don't 
-   try to call tdb_error or tdb_errname, just do strerror(errno).
-
-   @param name may be NULL for internal databases. */
-TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags,
-		      int open_flags, mode_t mode)
-{
-	return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL);
-}
-
-
-TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
-			 int open_flags, mode_t mode,
-			 tdb_log_func log_fn)
-{
-	TDB_CONTEXT *tdb;
-	struct stat st;
-	int rev = 0, locked;
-	unsigned char *vp;
-	u32 vertest;
-
-	if (!(tdb = calloc(1, sizeof *tdb))) {
-		/* Can't log this */
-		errno = ENOMEM;
-		goto fail;
-	}
-	tdb->fd = -1;
-	tdb->name = NULL;
-	tdb->map_ptr = NULL;
-	tdb->lockedkeys = NULL;
-	tdb->flags = tdb_flags;
-	tdb->open_flags = open_flags;
-	tdb->log_fn = log_fn;
-	
-	if ((open_flags & O_ACCMODE) == O_WRONLY) {
-		TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n",
-			 name));
-		errno = EINVAL;
-		goto fail;
-	}
-	
-	if (hash_size == 0)
-		hash_size = DEFAULT_HASH_SIZE;
-	if ((open_flags & O_ACCMODE) == O_RDONLY) {
-		tdb->read_only = 1;
-		/* read only databases don't do locking or clear if first */
-		tdb->flags |= TDB_NOLOCK;
-		tdb->flags &= ~TDB_CLEAR_IF_FIRST;
-	}
-
-	/* internal databases don't mmap or lock, and start off cleared */
-	if (tdb->flags & TDB_INTERNAL) {
-		tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
-		tdb->flags &= ~TDB_CLEAR_IF_FIRST;
-		if (tdb_new_database(tdb, hash_size) != 0) {
-			TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!"));
-			goto fail;
-		}
-		goto internal;
-	}
-
-	if ((tdb->fd = open(name, open_flags, mode)) == -1) {
-		TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n",
-			 name, strerror(errno)));
-		goto fail;	/* errno set by open(2) */
-	}
-
-	/* 
-	   Close file when execing another process.  
-	   Prevents SELinux access errors.
-	*/
-	set_cloexec_flag(tdb->fd, 1);
-
-	/* ensure there is only one process initialising at once */
-	if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) {
-		TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
-			 name, strerror(errno)));
-		goto fail;	/* errno set by tdb_brlock */
-	}
-
-	/* we need to zero database if we are the only one with it open */
-	if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))
-	    && (tdb_flags & TDB_CLEAR_IF_FIRST)) {
-		open_flags |= O_CREAT;
-		if (ftruncate(tdb->fd, 0) == -1) {
-			TDB_LOG((tdb, 0, "tdb_open_ex: "
-				 "failed to truncate %s: %s\n",
-				 name, strerror(errno)));
-			goto fail; /* errno set by ftruncate */
-		}
-	}
-
-	if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
-	    || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
-	    || (tdb->header.version != TDB_VERSION
-		&& !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
-		/* its not a valid database - possibly initialise it */
-		if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
-			errno = EIO; /* ie bad format or something */
-			goto fail;
-		}
-		rev = (tdb->flags & TDB_CONVERT);
-	}
-	vp = (unsigned char *)&tdb->header.version;
-	vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) |
-		  (((u32)vp[2]) << 8) | (u32)vp[3];
-	tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
-	if (!rev)
-		tdb->flags &= ~TDB_CONVERT;
-	else {
-		tdb->flags |= TDB_CONVERT;
-		convert(&tdb->header, sizeof(tdb->header));
-	}
-	if (fstat(tdb->fd, &st) == -1)
-		goto fail;
-
-	/* Is it already in the open list?  If so, fail. */
-	if (tdb_already_open(st.st_dev, st.st_ino)) {
-		TDB_LOG((tdb, 2, "tdb_open_ex: "
-			 "%s (%d:%d,%lld) is already open in this process\n",
-			 name, major(st.st_dev), minor(st.st_dev), (unsigned long long)st.st_ino));
-		errno = EBUSY;
-		goto fail;
-	}
-
-	if (!(tdb->name = (char *)strdup(name))) {
-		errno = ENOMEM;
-		goto fail;
-	}
-
-	tdb->map_size = st.st_size;
-	tdb->device = st.st_dev;
-	tdb->inode = st.st_ino;
-	tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0]));
-	if (!tdb->locked) {
-		TDB_LOG((tdb, 2, "tdb_open_ex: "
-			 "failed to allocate lock structure for %s\n",
-			 name));
-		errno = ENOMEM;
-		goto fail;
-	}
-	tdb_mmap(tdb);
-	if (locked) {
-		if (!tdb->read_only)
-			if (tdb_clear_spinlocks(tdb) != 0) {
-				TDB_LOG((tdb, 0, "tdb_open_ex: "
-				"failed to clear spinlock\n"));
-				goto fail;
-			}
-		if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
-			TDB_LOG((tdb, 0, "tdb_open_ex: "
-				 "failed to take ACTIVE_LOCK on %s: %s\n",
-				 name, strerror(errno)));
-			goto fail;
-		}
-	}
-	/* leave this lock in place to indicate it's in use */
-	if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
-		goto fail;
-
- internal:
-	/* Internal (memory-only) databases skip all the code above to
-	 * do with disk files, and resume here by releasing their
-	 * global lock and hooking into the active list. */
-	if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1)
-		goto fail;
-	tdb->next = tdbs;
-	tdbs = tdb;
-	return tdb;
-
- fail:
-	{ int save_errno = errno;
-
-	if (!tdb)
-		return NULL;
-	
-	if (tdb->map_ptr) {
-		if (tdb->flags & TDB_INTERNAL)
-			SAFE_FREE(tdb->map_ptr);
-		else
-			tdb_munmap(tdb);
-	}
-	SAFE_FREE(tdb->name);
-	if (tdb->fd != -1)
-		if (close(tdb->fd) != 0)
-			TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
-	SAFE_FREE(tdb->locked);
-	SAFE_FREE(tdb);
-	errno = save_errno;
-	return NULL;
-	}
-}
-
-/**
- * Close a database.
- *
- * @returns -1 for error; 0 for success.
- **/
-int tdb_close(TDB_CONTEXT *tdb)
-{
-	TDB_CONTEXT **i;
-	int ret = 0;
-
-	if (tdb->map_ptr) {
-		if (tdb->flags & TDB_INTERNAL)
-			SAFE_FREE(tdb->map_ptr);
-		else
-			tdb_munmap(tdb);
-	}
-	SAFE_FREE(tdb->name);
-	if (tdb->fd != -1)
-		ret = close(tdb->fd);
-	SAFE_FREE(tdb->locked);
-	SAFE_FREE(tdb->lockedkeys);
-
-	/* Remove from contexts list */
-	for (i = &tdbs; *i; i = &(*i)->next) {
-		if (*i == tdb) {
-			*i = tdb->next;
-			break;
-		}
-	}
-
-	memset(tdb, 0, sizeof(*tdb));
-	SAFE_FREE(tdb);
-
-	return ret;
-}
-
-/* lock/unlock entire database */
-int tdb_lockall(TDB_CONTEXT *tdb)
-{
-	u32 i;
-
-	/* There are no locks on read-only dbs */
-	if (tdb->read_only)
-		return TDB_ERRCODE(TDB_ERR_LOCK, -1);
-	if (tdb->lockedkeys)
-		return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
-	for (i = 0; i < tdb->header.hash_size; i++) 
-		if (tdb_lock(tdb, i, F_WRLCK))
-			break;
-
-	/* If error, release locks we have... */
-	if (i < tdb->header.hash_size) {
-		u32 j;
-
-		for ( j = 0; j < i; j++)
-			tdb_unlock(tdb, j, F_WRLCK);
-		return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
-	}
-
-	return 0;
-}
-void tdb_unlockall(TDB_CONTEXT *tdb)
-{
-	u32 i;
-	for (i=0; i < tdb->header.hash_size; i++)
-		tdb_unlock(tdb, i, F_WRLCK);
-}
-
-int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[])
-{
-	u32 i, j, hash;
-
-	/* Can't lock more keys if already locked */
-	if (tdb->lockedkeys)
-		return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
-	if (!(tdb->lockedkeys = malloc(sizeof(u32) * (number+1))))
-		return TDB_ERRCODE(TDB_ERR_OOM, -1);
-	/* First number in array is # keys */
-	tdb->lockedkeys[0] = number;
-
-	/* Insertion sort by bucket */
-	for (i = 0; i < number; i++) {
-		hash = tdb_hash(&keys[i]);
-		for (j = 0; j < i && BUCKET(tdb->lockedkeys[j+1]) < BUCKET(hash); j++);
-			memmove(&tdb->lockedkeys[j+2], &tdb->lockedkeys[j+1], sizeof(u32) * (i-j));
-		tdb->lockedkeys[j+1] = hash;
-	}
-	/* Finally, lock in order */
-	for (i = 0; i < number; i++)
-		if (tdb_lock(tdb, i, F_WRLCK))
-			break;
-
-	/* If error, release locks we have... */
-	if (i < number) {
-		for ( j = 0; j < i; j++)
-			tdb_unlock(tdb, j, F_WRLCK);
-		SAFE_FREE(tdb->lockedkeys);
-		return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
-	}
-	return 0;
-}
-
-/* Unlock the keys previously locked by tdb_lockkeys() */
-void tdb_unlockkeys(TDB_CONTEXT *tdb)
-{
-	u32 i;
-	if (!tdb->lockedkeys)
-		return;
-	for (i = 0; i < tdb->lockedkeys[0]; i++)
-		tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK);
-	SAFE_FREE(tdb->lockedkeys);
-}
-
-/* lock/unlock one hash chain. This is meant to be used to reduce
-   contention - it cannot guarantee how many records will be locked */
-int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
-}
-
-int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
-}
-
-int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK);
-}
-
-int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key)
-{
-	return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK);
-}
-
-
-/* register a loging function */
-void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...))
-{
-	tdb->log_fn = fn;
-}
-
-
-/* reopen a tdb - this is used after a fork to ensure that we have an independent
-   seek pointer from our parent and to re-establish locks */
-int tdb_reopen(TDB_CONTEXT *tdb)
-{
-	struct stat st;
-
-	if (tdb_munmap(tdb) != 0) {
-		TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
-		goto fail;
-	}
-	if (close(tdb->fd) != 0)
-		TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
-	tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
-	if (tdb->fd == -1) {
-		TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
-		goto fail;
-	}
-	if (fstat(tdb->fd, &st) != 0) {
-		TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
-		goto fail;
-	}
-	if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
-		TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
-		goto fail;
-	}
-	tdb_mmap(tdb);
-	if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) {
-		TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
-		goto fail;
-	}
-
-	return 0;
-
-fail:
-	tdb_close(tdb);
-	return -1;
-}
-
-/* reopen all tdb's */
-int tdb_reopen_all(void)
-{
-	TDB_CONTEXT *tdb;
-
-	for (tdb=tdbs; tdb; tdb = tdb->next) {
-		if (tdb_reopen(tdb) != 0) return -1;
-	}
-
-	return 0;
-}