Remove our copies of the samba libraries.

Packages are already available in debian unstable and will soon land in Fedora.
See BUILD.TXT for details.
We still keep libreplace as we still use its configure macros, until we find
time to extract only waht we need and have our own macros.

1 files changed, 0 insertions, 1119 deletions

diff --git a/tdb/common/transaction.c b/tdb/common/transaction.c
deleted file mode 100644
index 7acda640c..000000000
--- a/tdb/common/transaction.c
+++ /dev/null
@@ -1,1119 +0,0 @@
- /* 
-   Unix SMB/CIFS implementation.
-
-   trivial database library
-
-   Copyright (C) Andrew Tridgell              2005
-
-     ** 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"
-
-/*
-  transaction design:
-
-  - only allow a single transaction at a time per database. This makes
-    using the transaction API simpler, as otherwise the caller would
-    have to cope with temporary failures in transactions that conflict
-    with other current transactions
-
-  - keep the transaction recovery information in the same file as the
-    database, using a special 'transaction recovery' record pointed at
-    by the header. This removes the need for extra journal files as
-    used by some other databases
-
-  - dynamically allocated the transaction recover record, re-using it
-    for subsequent transactions. If a larger record is needed then
-    tdb_free() the old record to place it on the normal tdb freelist
-    before allocating the new record
-
-  - during transactions, keep a linked list of writes all that have
-    been performed by intercepting all tdb_write() calls. The hooked
-    transaction versions of tdb_read() and tdb_write() check this
-    linked list and try to use the elements of the list in preference
-    to the real database.
-
-  - don't allow any locks to be held when a transaction starts,
-    otherwise we can end up with deadlock (plus lack of lock nesting
-    in posix locks would mean the lock is lost)
-
-  - if the caller gains a lock during the transaction but doesn't
-    release it then fail the commit
-
-  - allow for nested calls to tdb_transaction_start(), re-using the
-    existing transaction record. If the inner transaction is cancelled
-    then a subsequent commit will fail
- 
-  - keep a mirrored copy of the tdb hash chain heads to allow for the
-    fast hash heads scan on traverse, updating the mirrored copy in
-    the transaction version of tdb_write
-
-  - allow callers to mix transaction and non-transaction use of tdb,
-    although once a transaction is started then an exclusive lock is
-    gained until the transaction is committed or cancelled
-
-  - the commit stategy involves first saving away all modified data
-    into a linearised buffer in the transaction recovery area, then
-    marking the transaction recovery area with a magic value to
-    indicate a valid recovery record. In total 4 fsync/msync calls are
-    needed per commit to prevent race conditions. It might be possible
-    to reduce this to 3 or even 2 with some more work.
-
-  - check for a valid recovery record on open of the tdb, while the
-    global lock is held. Automatically recover from the transaction
-    recovery area if needed, then continue with the open as
-    usual. This allows for smooth crash recovery with no administrator
-    intervention.
-
-  - if TDB_NOSYNC is passed to flags in tdb_open then transactions are
-    still available, but no transaction recovery area is used and no
-    fsync/msync calls are made.
-
-*/
-
-
-/*
-  hold the context of any current transaction
-*/
-struct tdb_transaction {
-	/* we keep a mirrored copy of the tdb hash heads here so
-	   tdb_next_hash_chain() can operate efficiently */
-	uint32_t *hash_heads;
-
-	/* the original io methods - used to do IOs to the real db */
-	const struct tdb_methods *io_methods;
-
-	/* the list of transaction blocks. When a block is first
-	   written to, it gets created in this list */
-	uint8_t **blocks;
-	uint32_t num_blocks;
-	uint32_t block_size;      /* bytes in each block */
-	uint32_t last_block_size; /* number of valid bytes in the last block */
-
-	/* non-zero when an internal transaction error has
-	   occurred. All write operations will then fail until the
-	   transaction is ended */
-	int transaction_error;
-
-	/* when inside a transaction we need to keep track of any
-	   nested tdb_transaction_start() calls, as these are allowed,
-	   but don't create a new transaction */
-	int nesting;
-
-	/* old file size before transaction */
-	tdb_len_t old_map_size;
-};
-
-
-/*
-  read while in a transaction. We need to check first if the data is in our list
-  of transaction elements, then if not do a real read
-*/
-static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf, 
-			    tdb_len_t len, int cv)
-{
-	uint32_t blk;
-
-	/* break it down into block sized ops */
-	while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
-		tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
-		if (transaction_read(tdb, off, buf, len2, cv) != 0) {
-			return -1;
-		}
-		len -= len2;
-		off += len2;
-		buf = (void *)(len2 + (char *)buf);
-	}
-
-	if (len == 0) {
-		return 0;
-	}
-
-	blk = off / tdb->transaction->block_size;
-
-	/* see if we have it in the block list */
-	if (tdb->transaction->num_blocks <= blk ||
-	    tdb->transaction->blocks[blk] == NULL) {
-		/* nope, do a real read */
-		if (tdb->transaction->io_methods->tdb_read(tdb, off, buf, len, cv) != 0) {
-			goto fail;
-		}
-		return 0;
-	}
-
-	/* it is in the block list. Now check for the last block */
-	if (blk == tdb->transaction->num_blocks-1) {
-		if (len > tdb->transaction->last_block_size) {
-			goto fail;
-		}
-	}
-	
-	/* now copy it out of this block */
-	memcpy(buf, tdb->transaction->blocks[blk] + (off % tdb->transaction->block_size), len);
-	if (cv) {
-		tdb_convert(buf, len);
-	}
-	return 0;
-
-fail:
-	TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_read: failed at off=%d len=%d\n", off, len));
-	tdb->ecode = TDB_ERR_IO;
-	tdb->transaction->transaction_error = 1;
-	return -1;
-}
-
-
-/*
-  write while in a transaction
-*/
-static int transaction_write(struct tdb_context *tdb, tdb_off_t off, 
-			     const void *buf, tdb_len_t len)
-{
-	uint32_t blk;
-
-	/* if the write is to a hash head, then update the transaction
-	   hash heads */
-	if (len == sizeof(tdb_off_t) && off >= FREELIST_TOP &&
-	    off < FREELIST_TOP+TDB_HASHTABLE_SIZE(tdb)) {
-		uint32_t chain = (off-FREELIST_TOP) / sizeof(tdb_off_t);
-		memcpy(&tdb->transaction->hash_heads[chain], buf, len);
-	}
-
-	/* break it up into block sized chunks */
-	while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
-		tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
-		if (transaction_write(tdb, off, buf, len2) != 0) {
-			return -1;
-		}
-		len -= len2;
-		off += len2;
-		if (buf != NULL) {
-			buf = (const void *)(len2 + (const char *)buf);
-		}
-	}
-
-	if (len == 0) {
-		return 0;
-	}
-
-	blk = off / tdb->transaction->block_size;
-	off = off % tdb->transaction->block_size;
-
-	if (tdb->transaction->num_blocks <= blk) {
-		uint8_t **new_blocks;
-		/* expand the blocks array */
-		if (tdb->transaction->blocks == NULL) {
-			new_blocks = (uint8_t **)malloc(
-				(blk+1)*sizeof(uint8_t *));
-		} else {
-			new_blocks = (uint8_t **)realloc(
-				tdb->transaction->blocks,
-				(blk+1)*sizeof(uint8_t *));
-		}
-		if (new_blocks == NULL) {
-			tdb->ecode = TDB_ERR_OOM;
-			goto fail;
-		}
-		memset(&new_blocks[tdb->transaction->num_blocks], 0, 
-		       (1+(blk - tdb->transaction->num_blocks))*sizeof(uint8_t *));
-		tdb->transaction->blocks = new_blocks;
-		tdb->transaction->num_blocks = blk+1;
-		tdb->transaction->last_block_size = 0;
-	}
-
-	/* allocate and fill a block? */
-	if (tdb->transaction->blocks[blk] == NULL) {
-		tdb->transaction->blocks[blk] = (uint8_t *)calloc(tdb->transaction->block_size, 1);
-		if (tdb->transaction->blocks[blk] == NULL) {
-			tdb->ecode = TDB_ERR_OOM;
-			tdb->transaction->transaction_error = 1;
-			return -1;			
-		}
-		if (tdb->transaction->old_map_size > blk * tdb->transaction->block_size) {
-			tdb_len_t len2 = tdb->transaction->block_size;
-			if (len2 + (blk * tdb->transaction->block_size) > tdb->transaction->old_map_size) {
-				len2 = tdb->transaction->old_map_size - (blk * tdb->transaction->block_size);
-			}
-			if (tdb->transaction->io_methods->tdb_read(tdb, blk * tdb->transaction->block_size, 
-								   tdb->transaction->blocks[blk], 
-								   len2, 0) != 0) {
-				SAFE_FREE(tdb->transaction->blocks[blk]);				
-				tdb->ecode = TDB_ERR_IO;
-				goto fail;
-			}
-			if (blk == tdb->transaction->num_blocks-1) {
-				tdb->transaction->last_block_size = len2;
-			}			
-		}
-	}
-	
-	/* overwrite part of an existing block */
-	if (buf == NULL) {
-		memset(tdb->transaction->blocks[blk] + off, 0, len);
-	} else {
-		memcpy(tdb->transaction->blocks[blk] + off, buf, len);
-	}
-	if (blk == tdb->transaction->num_blocks-1) {
-		if (len + off > tdb->transaction->last_block_size) {
-			tdb->transaction->last_block_size = len + off;
-		}
-	}
-
-	return 0;
-
-fail:
-	TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_write: failed at off=%d len=%d\n", 
-		 (blk*tdb->transaction->block_size) + off, len));
-	tdb->transaction->transaction_error = 1;
-	return -1;
-}
-
-
-/*
-  write while in a transaction - this varient never expands the transaction blocks, it only
-  updates existing blocks. This means it cannot change the recovery size
-*/
-static int transaction_write_existing(struct tdb_context *tdb, tdb_off_t off, 
-				      const void *buf, tdb_len_t len)
-{
-	uint32_t blk;
-
-	/* break it up into block sized chunks */
-	while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
-		tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
-		if (transaction_write_existing(tdb, off, buf, len2) != 0) {
-			return -1;
-		}
-		len -= len2;
-		off += len2;
-		if (buf != NULL) {
-			buf = (const void *)(len2 + (const char *)buf);
-		}
-	}
-
-	if (len == 0) {
-		return 0;
-	}
-
-	blk = off / tdb->transaction->block_size;
-	off = off % tdb->transaction->block_size;
-
-	if (tdb->transaction->num_blocks <= blk ||
-	    tdb->transaction->blocks[blk] == NULL) {
-		return 0;
-	}
-
-	if (blk == tdb->transaction->num_blocks-1 &&
-	    off + len > tdb->transaction->last_block_size) {
-		if (off >= tdb->transaction->last_block_size) {
-			return 0;
-		}
-		len = tdb->transaction->last_block_size - off;
-	}
-
-	/* overwrite part of an existing block */
-	memcpy(tdb->transaction->blocks[blk] + off, buf, len);
-
-	return 0;
-}
-
-
-/*
-  accelerated hash chain head search, using the cached hash heads
-*/
-static void transaction_next_hash_chain(struct tdb_context *tdb, uint32_t *chain)
-{
-	uint32_t h = *chain;
-	for (;h < tdb->header.hash_size;h++) {
-		/* the +1 takes account of the freelist */
-		if (0 != tdb->transaction->hash_heads[h+1]) {
-			break;
-		}
-	}
-	(*chain) = h;
-}
-
-/*
-  out of bounds check during a transaction
-*/
-static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, int probe)
-{
-	if (len <= tdb->map_size) {
-		return 0;
-	}
-	return TDB_ERRCODE(TDB_ERR_IO, -1);
-}
-
-/*
-  transaction version of tdb_expand().
-*/
-static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t size, 
-				   tdb_off_t addition)
-{
-	/* add a write to the transaction elements, so subsequent
-	   reads see the zero data */
-	if (transaction_write(tdb, size, NULL, addition) != 0) {
-		return -1;
-	}
-
-	return 0;
-}
-
-/*
-  brlock during a transaction - ignore them
-*/
-static int transaction_brlock(struct tdb_context *tdb, tdb_off_t offset, 
-			      int rw_type, int lck_type, int probe, size_t len)
-{
-	return 0;
-}
-
-static const struct tdb_methods transaction_methods = {
-	transaction_read,
-	transaction_write,
-	transaction_next_hash_chain,
-	transaction_oob,
-	transaction_expand_file,
-	transaction_brlock
-};
-
-
-/*
-  start a tdb transaction. No token is returned, as only a single
-  transaction is allowed to be pending per tdb_context
-*/
-int tdb_transaction_start(struct tdb_context *tdb)
-{
-	/* some sanity checks */
-	if (tdb->read_only || (tdb->flags & TDB_INTERNAL) || tdb->traverse_read) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction on a read-only or internal db\n"));
-		tdb->ecode = TDB_ERR_EINVAL;
-		return -1;
-	}
-
-	/* cope with nested tdb_transaction_start() calls */
-	if (tdb->transaction != NULL) {
-		tdb->transaction->nesting++;
-		TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: nesting %d\n", 
-			 tdb->transaction->nesting));
-		return 0;
-	}
-
-	if (tdb->num_locks != 0 || tdb->global_lock.count) {
-		/* the caller must not have any locks when starting a
-		   transaction as otherwise we'll be screwed by lack
-		   of nested locks in posix */
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction with locks held\n"));
-		tdb->ecode = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	if (tdb->travlocks.next != NULL) {
-		/* you cannot use transactions inside a traverse (although you can use
-		   traverse inside a transaction) as otherwise you can end up with
-		   deadlock */
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction within a traverse\n"));
-		tdb->ecode = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	tdb->transaction = (struct tdb_transaction *)
-		calloc(sizeof(struct tdb_transaction), 1);
-	if (tdb->transaction == NULL) {
-		tdb->ecode = TDB_ERR_OOM;
-		return -1;
-	}
-
-	/* a page at a time seems like a reasonable compromise between compactness and efficiency */
-	tdb->transaction->block_size = tdb->page_size;
-
-	/* get the transaction write lock. This is a blocking lock. As
-	   discussed with Volker, there are a number of ways we could
-	   make this async, which we will probably do in the future */
-	if (tdb_transaction_lock(tdb, F_WRLCK) == -1) {
-		SAFE_FREE(tdb->transaction->blocks);
-		SAFE_FREE(tdb->transaction);
-		return -1;
-	}
-	
-	/* get a read lock from the freelist to the end of file. This
-	   is upgraded to a write lock during the commit */
-	if (tdb_brlock(tdb, FREELIST_TOP, F_RDLCK, F_SETLKW, 0, 0) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to get hash locks\n"));
-		tdb->ecode = TDB_ERR_LOCK;
-		goto fail;
-	}
-
-	/* setup a copy of the hash table heads so the hash scan in
-	   traverse can be fast */
-	tdb->transaction->hash_heads = (uint32_t *)
-		calloc(tdb->header.hash_size+1, sizeof(uint32_t));
-	if (tdb->transaction->hash_heads == NULL) {
-		tdb->ecode = TDB_ERR_OOM;
-		goto fail;
-	}
-	if (tdb->methods->tdb_read(tdb, FREELIST_TOP, tdb->transaction->hash_heads,
-				   TDB_HASHTABLE_SIZE(tdb), 0) != 0) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_start: failed to read hash heads\n"));
-		tdb->ecode = TDB_ERR_IO;
-		goto fail;
-	}
-
-	/* make sure we know about any file expansions already done by
-	   anyone else */
-	tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
-	tdb->transaction->old_map_size = tdb->map_size;
-
-	/* finally hook the io methods, replacing them with
-	   transaction specific methods */
-	tdb->transaction->io_methods = tdb->methods;
-	tdb->methods = &transaction_methods;
-
-	return 0;
-	
-fail:
-	tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0);
-	tdb_transaction_unlock(tdb);
-	SAFE_FREE(tdb->transaction->blocks);
-	SAFE_FREE(tdb->transaction->hash_heads);
-	SAFE_FREE(tdb->transaction);
-	return -1;
-}
-
-
-/*
-  cancel the current transaction
-*/
-int tdb_transaction_cancel(struct tdb_context *tdb)
-{	
-	int i;
-
-	if (tdb->transaction == NULL) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_cancel: no transaction\n"));
-		return -1;
-	}
-
-	if (tdb->transaction->nesting != 0) {
-		tdb->transaction->transaction_error = 1;
-		tdb->transaction->nesting--;
-		return 0;
-	}		
-
-	tdb->map_size = tdb->transaction->old_map_size;
-
-	/* free all the transaction blocks */
-	for (i=0;i<tdb->transaction->num_blocks;i++) {
-		if (tdb->transaction->blocks[i] != NULL) {
-			free(tdb->transaction->blocks[i]);
-		}
-	}
-	SAFE_FREE(tdb->transaction->blocks);
-
-	/* remove any global lock created during the transaction */
-	if (tdb->global_lock.count != 0) {
-		tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 4*tdb->header.hash_size);
-		tdb->global_lock.count = 0;
-	}
-
-	/* remove any locks created during the transaction */
-	if (tdb->num_locks != 0) {
-		for (i=0;i<tdb->num_lockrecs;i++) {
-			tdb_brlock(tdb,FREELIST_TOP+4*tdb->lockrecs[i].list,
-				   F_UNLCK,F_SETLKW, 0, 1);
-		}
-		tdb->num_locks = 0;
-		tdb->num_lockrecs = 0;
-		SAFE_FREE(tdb->lockrecs);
-	}
-
-	/* restore the normal io methods */
-	tdb->methods = tdb->transaction->io_methods;
-
-	tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0);
-	tdb_transaction_unlock(tdb);
-	SAFE_FREE(tdb->transaction->hash_heads);
-	SAFE_FREE(tdb->transaction);
-	
-	return 0;
-}
-
-/*
-  sync to disk
-*/
-static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length)
-{	
-	if (fsync(tdb->fd) != 0) {
-		tdb->ecode = TDB_ERR_IO;
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: fsync failed\n"));
-		return -1;
-	}
-#ifdef HAVE_MMAP
-	if (tdb->map_ptr) {
-		tdb_off_t moffset = offset & ~(tdb->page_size-1);
-		if (msync(moffset + (char *)tdb->map_ptr, 
-			  length + (offset - moffset), MS_SYNC) != 0) {
-			tdb->ecode = TDB_ERR_IO;
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: msync failed - %s\n",
-				 strerror(errno)));
-			return -1;
-		}
-	}
-#endif
-	return 0;
-}
-
-
-/*
-  work out how much space the linearised recovery data will consume
-*/
-static tdb_len_t tdb_recovery_size(struct tdb_context *tdb)
-{
-	tdb_len_t recovery_size = 0;
-	int i;
-
-	recovery_size = sizeof(uint32_t);
-	for (i=0;i<tdb->transaction->num_blocks;i++) {
-		if (i * tdb->transaction->block_size >= tdb->transaction->old_map_size) {
-			break;
-		}
-		if (tdb->transaction->blocks[i] == NULL) {
-			continue;
-		}
-		recovery_size += 2*sizeof(tdb_off_t);
-		if (i == tdb->transaction->num_blocks-1) {
-			recovery_size += tdb->transaction->last_block_size;
-		} else {
-			recovery_size += tdb->transaction->block_size;
-		}
-	}	
-
-	return recovery_size;
-}
-
-/*
-  allocate the recovery area, or use an existing recovery area if it is
-  large enough
-*/
-static int tdb_recovery_allocate(struct tdb_context *tdb, 
-				 tdb_len_t *recovery_size,
-				 tdb_off_t *recovery_offset,
-				 tdb_len_t *recovery_max_size)
-{
-	struct list_struct rec;
-	const struct tdb_methods *methods = tdb->transaction->io_methods;
-	tdb_off_t recovery_head;
-
-	if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery head\n"));
-		return -1;
-	}
-
-	rec.rec_len = 0;
-
-	if (recovery_head != 0 && 
-	    methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery record\n"));
-		return -1;
-	}
-
-	*recovery_size = tdb_recovery_size(tdb);
-
-	if (recovery_head != 0 && *recovery_size <= rec.rec_len) {
-		/* it fits in the existing area */
-		*recovery_max_size = rec.rec_len;
-		*recovery_offset = recovery_head;
-		return 0;
-	}
-
-	/* we need to free up the old recovery area, then allocate a
-	   new one at the end of the file. Note that we cannot use
-	   tdb_allocate() to allocate the new one as that might return
-	   us an area that is being currently used (as of the start of
-	   the transaction) */
-	if (recovery_head != 0) {
-		if (tdb_free(tdb, recovery_head, &rec) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to free previous recovery area\n"));
-			return -1;
-		}
-	}
-
-	/* the tdb_free() call might have increased the recovery size */
-	*recovery_size = tdb_recovery_size(tdb);
-
-	/* round up to a multiple of page size */
-	*recovery_max_size = TDB_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec);
-	*recovery_offset = tdb->map_size;
-	recovery_head = *recovery_offset;
-
-	if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, 
-				     (tdb->map_size - tdb->transaction->old_map_size) +
-				     sizeof(rec) + *recovery_max_size) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to create recovery area\n"));
-		return -1;
-	}
-
-	/* remap the file (if using mmap) */
-	methods->tdb_oob(tdb, tdb->map_size + 1, 1);
-
-	/* we have to reset the old map size so that we don't try to expand the file
-	   again in the transaction commit, which would destroy the recovery area */
-	tdb->transaction->old_map_size = tdb->map_size;
-
-	/* write the recovery header offset and sync - we can sync without a race here
-	   as the magic ptr in the recovery record has not been set */
-	CONVERT(recovery_head);
-	if (methods->tdb_write(tdb, TDB_RECOVERY_HEAD, 
-			       &recovery_head, sizeof(tdb_off_t)) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to write recovery head\n"));
-		return -1;
-	}
-	if (transaction_write_existing(tdb, TDB_RECOVERY_HEAD, &recovery_head, sizeof(tdb_off_t)) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to write recovery head\n"));
-		return -1;
-	}
-
-	return 0;
-}
-
-
-/*
-  setup the recovery data that will be used on a crash during commit
-*/
-static int transaction_setup_recovery(struct tdb_context *tdb, 
-				      tdb_off_t *magic_offset)
-{
-	tdb_len_t recovery_size;
-	unsigned char *data, *p;
-	const struct tdb_methods *methods = tdb->transaction->io_methods;
-	struct list_struct *rec;
-	tdb_off_t recovery_offset, recovery_max_size;
-	tdb_off_t old_map_size = tdb->transaction->old_map_size;
-	uint32_t magic, tailer;
-	int i;
-
-	/*
-	  check that the recovery area has enough space
-	*/
-	if (tdb_recovery_allocate(tdb, &recovery_size, 
-				  &recovery_offset, &recovery_max_size) == -1) {
-		return -1;
-	}
-
-	data = (unsigned char *)malloc(recovery_size + sizeof(*rec));
-	if (data == NULL) {
-		tdb->ecode = TDB_ERR_OOM;
-		return -1;
-	}
-
-	rec = (struct list_struct *)data;
-	memset(rec, 0, sizeof(*rec));
-
-	rec->magic    = 0;
-	rec->data_len = recovery_size;
-	rec->rec_len  = recovery_max_size;
-	rec->key_len  = old_map_size;
-	CONVERT(rec);
-
-	/* build the recovery data into a single blob to allow us to do a single
-	   large write, which should be more efficient */
-	p = data + sizeof(*rec);
-	for (i=0;i<tdb->transaction->num_blocks;i++) {
-		tdb_off_t offset;
-		tdb_len_t length;
-
-		if (tdb->transaction->blocks[i] == NULL) {
-			continue;
-		}
-
-		offset = i * tdb->transaction->block_size;
-		length = tdb->transaction->block_size;
-		if (i == tdb->transaction->num_blocks-1) {
-			length = tdb->transaction->last_block_size;
-		}
-		
-		if (offset >= old_map_size) {
-			continue;
-		}
-		if (offset + length > tdb->transaction->old_map_size) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: transaction data over new region boundary\n"));
-			free(data);
-			tdb->ecode = TDB_ERR_CORRUPT;
-			return -1;
-		}
-		memcpy(p, &offset, 4);
-		memcpy(p+4, &length, 4);
-		if (DOCONV()) {
-			tdb_convert(p, 8);
-		}
-		/* the recovery area contains the old data, not the
-		   new data, so we have to call the original tdb_read
-		   method to get it */
-		if (methods->tdb_read(tdb, offset, p + 8, length, 0) != 0) {
-			free(data);
-			tdb->ecode = TDB_ERR_IO;
-			return -1;
-		}
-		p += 8 + length;
-	}
-
-	/* and the tailer */
-	tailer = sizeof(*rec) + recovery_max_size;
-	memcpy(p, &tailer, 4);
-	CONVERT(p);
-
-	/* write the recovery data to the recovery area */
-	if (methods->tdb_write(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery data\n"));
-		free(data);
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-	if (transaction_write_existing(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write secondary recovery data\n"));
-		free(data);
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	/* as we don't have ordered writes, we have to sync the recovery
-	   data before we update the magic to indicate that the recovery
-	   data is present */
-	if (transaction_sync(tdb, recovery_offset, sizeof(*rec) + recovery_size) == -1) {
-		free(data);
-		return -1;
-	}
-
-	free(data);
-
-	magic = TDB_RECOVERY_MAGIC;
-	CONVERT(magic);
-
-	*magic_offset = recovery_offset + offsetof(struct list_struct, magic);
-
-	if (methods->tdb_write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery magic\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-	if (transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write secondary recovery magic\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	/* ensure the recovery magic marker is on disk */
-	if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) {
-		return -1;
-	}
-
-	return 0;
-}
-
-/*
-  commit the current transaction
-*/
-int tdb_transaction_commit(struct tdb_context *tdb)
-{	
-	const struct tdb_methods *methods;
-	tdb_off_t magic_offset = 0;
-	uint32_t zero = 0;
-	int i;
-
-	if (tdb->transaction == NULL) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: no transaction\n"));
-		return -1;
-	}
-
-	if (tdb->transaction->transaction_error) {
-		tdb->ecode = TDB_ERR_IO;
-		tdb_transaction_cancel(tdb);
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: transaction error pending\n"));
-		return -1;
-	}
-
-
-	if (tdb->transaction->nesting != 0) {
-		tdb->transaction->nesting--;
-		return 0;
-	}		
-
-	/* check for a null transaction */
-	if (tdb->transaction->blocks == NULL) {
-		tdb_transaction_cancel(tdb);
-		return 0;
-	}
-
-	methods = tdb->transaction->io_methods;
-	
-	/* if there are any locks pending then the caller has not
-	   nested their locks properly, so fail the transaction */
-	if (tdb->num_locks || tdb->global_lock.count) {
-		tdb->ecode = TDB_ERR_LOCK;
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: locks pending on commit\n"));
-		tdb_transaction_cancel(tdb);
-		return -1;
-	}
-
-	/* upgrade the main transaction lock region to a write lock */
-	if (tdb_brlock_upgrade(tdb, FREELIST_TOP, 0) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to upgrade hash locks\n"));
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb_transaction_cancel(tdb);
-		return -1;
-	}
-
-	/* get the global lock - this prevents new users attaching to the database
-	   during the commit */
-	if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: failed to get global lock\n"));
-		tdb->ecode = TDB_ERR_LOCK;
-		tdb_transaction_cancel(tdb);
-		return -1;
-	}
-
-	if (!(tdb->flags & TDB_NOSYNC)) {
-		/* write the recovery data to the end of the file */
-		if (transaction_setup_recovery(tdb, &magic_offset) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to setup recovery data\n"));
-			tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-			tdb_transaction_cancel(tdb);
-			return -1;
-		}
-	}
-
-	/* expand the file to the new size if needed */
-	if (tdb->map_size != tdb->transaction->old_map_size) {
-		if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, 
-					     tdb->map_size - 
-					     tdb->transaction->old_map_size) == -1) {
-			tdb->ecode = TDB_ERR_IO;
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: expansion failed\n"));
-			tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-			tdb_transaction_cancel(tdb);
-			return -1;
-		}
-		tdb->map_size = tdb->transaction->old_map_size;
-		methods->tdb_oob(tdb, tdb->map_size + 1, 1);
-	}
-
-	/* perform all the writes */
-	for (i=0;i<tdb->transaction->num_blocks;i++) {
-		tdb_off_t offset;
-		tdb_len_t length;
-
-		if (tdb->transaction->blocks[i] == NULL) {
-			continue;
-		}
-
-		offset = i * tdb->transaction->block_size;
-		length = tdb->transaction->block_size;
-		if (i == tdb->transaction->num_blocks-1) {
-			length = tdb->transaction->last_block_size;
-		}
-
-		if (methods->tdb_write(tdb, offset, tdb->transaction->blocks[i], length) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed during commit\n"));
-			
-			/* we've overwritten part of the data and
-			   possibly expanded the file, so we need to
-			   run the crash recovery code */
-			tdb->methods = methods;
-			tdb_transaction_recover(tdb); 
-
-			tdb_transaction_cancel(tdb);
-			tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed\n"));
-			return -1;
-		}
-		SAFE_FREE(tdb->transaction->blocks[i]);
-	} 
-
-	SAFE_FREE(tdb->transaction->blocks);
-	tdb->transaction->num_blocks = 0;
-
-	if (!(tdb->flags & TDB_NOSYNC)) {
-		/* ensure the new data is on disk */
-		if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
-			return -1;
-		}
-
-		/* remove the recovery marker */
-		if (methods->tdb_write(tdb, magic_offset, &zero, 4) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to remove recovery magic\n"));
-			return -1;
-		}
-
-		/* ensure the recovery marker has been removed on disk */
-		if (transaction_sync(tdb, magic_offset, 4) == -1) {
-			return -1;
-		}
-	}
-
-	tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-
-	/*
-	  TODO: maybe write to some dummy hdr field, or write to magic
-	  offset without mmap, before the last sync, instead of the
-	  utime() call
-	*/
-
-	/* on some systems (like Linux 2.6.x) changes via mmap/msync
-	   don't change the mtime of the file, this means the file may
-	   not be backed up (as tdb rounding to block sizes means that
-	   file size changes are quite rare too). The following forces
-	   mtime changes when a transaction completes */
-#ifdef HAVE_UTIME
-	utime(tdb->name, NULL);
-#endif
-
-	/* use a transaction cancel to free memory and remove the
-	   transaction locks */
-	tdb_transaction_cancel(tdb);
-
-	return 0;
-}
-
-
-/*
-  recover from an aborted transaction. Must be called with exclusive
-  database write access already established (including the global
-  lock to prevent new processes attaching)
-*/
-int tdb_transaction_recover(struct tdb_context *tdb)
-{
-	tdb_off_t recovery_head, recovery_eof;
-	unsigned char *data, *p;
-	uint32_t zero = 0;
-	struct list_struct rec;
-
-	/* find the recovery area */
-	if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery head\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	if (recovery_head == 0) {
-		/* we have never allocated a recovery record */
-		return 0;
-	}
-
-	/* read the recovery record */
-	if (tdb->methods->tdb_read(tdb, recovery_head, &rec, 
-				   sizeof(rec), DOCONV()) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery record\n"));		
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	if (rec.magic != TDB_RECOVERY_MAGIC) {
-		/* there is no valid recovery data */
-		return 0;
-	}
-
-	if (tdb->read_only) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: attempt to recover read only database\n"));
-		tdb->ecode = TDB_ERR_CORRUPT;
-		return -1;
-	}
-
-	recovery_eof = rec.key_len;
-
-	data = (unsigned char *)malloc(rec.data_len);
-	if (data == NULL) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to allocate recovery data\n"));		
-		tdb->ecode = TDB_ERR_OOM;
-		return -1;
-	}
-
-	/* read the full recovery data */
-	if (tdb->methods->tdb_read(tdb, recovery_head + sizeof(rec), data,
-				   rec.data_len, 0) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery data\n"));		
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	/* recover the file data */
-	p = data;
-	while (p+8 < data + rec.data_len) {
-		uint32_t ofs, len;
-		if (DOCONV()) {
-			tdb_convert(p, 8);
-		}
-		memcpy(&ofs, p, 4);
-		memcpy(&len, p+4, 4);
-
-		if (tdb->methods->tdb_write(tdb, ofs, p+8, len) == -1) {
-			free(data);
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to recover %d bytes at offset %d\n", len, ofs));
-			tdb->ecode = TDB_ERR_IO;
-			return -1;
-		}
-		p += 8 + len;
-	}
-
-	free(data);
-
-	if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync recovery\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	/* if the recovery area is after the recovered eof then remove it */
-	if (recovery_eof <= recovery_head) {
-		if (tdb_ofs_write(tdb, TDB_RECOVERY_HEAD, &zero) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery head\n"));
-			tdb->ecode = TDB_ERR_IO;
-			return -1;			
-		}
-	}
-
-	/* remove the recovery magic */
-	if (tdb_ofs_write(tdb, recovery_head + offsetof(struct list_struct, magic), 
-			  &zero) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery magic\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;			
-	}
-	
-	/* reduce the file size to the old size */
-	tdb_munmap(tdb);
-	if (ftruncate(tdb->fd, recovery_eof) != 0) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to reduce to recovery size\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;			
-	}
-	tdb->map_size = recovery_eof;
-	tdb_mmap(tdb);
-
-	if (transaction_sync(tdb, 0, recovery_eof) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync2 recovery\n"));
-		tdb->ecode = TDB_ERR_IO;
-		return -1;
-	}
-
-	TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_recover: recovered %d byte database\n", 
-		 recovery_eof));
-
-	/* all done */
-	return 0;
-}