X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftransaction.c;h=2cab4655661768a80e44593211f152dd3c73175c;hp=6e0b1669fcd9fa1e2276282e621856f1f8236c3c;hb=2b5cb9bd6be4e61870ba7a400d1a9d91c5933371;hpb=51a56b52627e635566253a3fae081c3f466b6bb6

diff --git a/ccan/tdb2/transaction.c b/ccan/tdb2/transaction.c
index 6e0b1669..2cab4655 100644
--- a/ccan/tdb2/transaction.c
+++ b/ccan/tdb2/transaction.c
@@ -53,13 +53,13 @@
 
   - 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)
+    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
+    existing transaction record. If the inner transaction is canceled
     then a subsequent commit will fail
 
   - keep a mirrored copy of the tdb hash chain heads to allow for the
@@ -68,7 +68,7 @@
 
   - 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
+    gained until the transaction is committed or canceled
 
   - the commit stategy involves first saving away all modified data
     into a linearised buffer in the transaction recovery area, then
@@ -125,16 +125,18 @@ struct tdb_transaction {
   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)
+static enum TDB_ERROR transaction_read(struct tdb_context *tdb, tdb_off_t off,
+				       void *buf, tdb_len_t len)
 {
 	size_t blk;
+	enum TDB_ERROR ecode;
 
 	/* break it down into block sized ops */
 	while (len + (off % getpagesize()) > getpagesize()) {
 		tdb_len_t len2 = getpagesize() - (off % getpagesize());
-		if (transaction_read(tdb, off, buf, len2) != 0) {
-			return -1;
+		ecode = transaction_read(tdb, off, buf, len2);
+		if (ecode != TDB_SUCCESS) {
+			return ecode;
 		}
 		len -= len2;
 		off += len2;
@@ -142,7 +144,7 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	}
 
 	if (len == 0) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	blk = off / getpagesize();
@@ -151,7 +153,8 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	if (tdb->transaction->num_blocks <= blk ||
 	    tdb->transaction->blocks[blk] == NULL) {
 		/* nope, do a real read */
-		if (tdb->transaction->io_methods->read(tdb, off, buf, len) != 0) {
+		ecode = tdb->transaction->io_methods->tread(tdb, off, buf, len);
+		if (ecode != TDB_SUCCESS) {
 			goto fail;
 		}
 		return 0;
@@ -160,43 +163,45 @@ static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
 	/* 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) {
+			ecode = TDB_ERR_IO;
 			goto fail;
 		}
 	}
 
 	/* now copy it out of this block */
 	memcpy(buf, tdb->transaction->blocks[blk] + (off % getpagesize()), len);
-	return 0;
+	return TDB_SUCCESS;
 
 fail:
-	tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-		   "transaction_read: failed at off=%zu len=%zu",
-		   (size_t)off, (size_t)len);
 	tdb->transaction->transaction_error = 1;
-	return -1;
+	return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+			  "transaction_read: failed at off=%zu len=%zu",
+			  (size_t)off, (size_t)len);
 }
 
 
 /*
   write while in a transaction
 */
-static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
-			     const void *buf, tdb_len_t len)
+static enum TDB_ERROR transaction_write(struct tdb_context *tdb, tdb_off_t off,
+					const void *buf, tdb_len_t len)
 {
 	size_t blk;
+	enum TDB_ERROR ecode;
 
 	/* Only a commit is allowed on a prepared transaction */
 	if (tdb->transaction->prepared) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_FATAL,
-			 "transaction_write: transaction already prepared,"
-			 " write not allowed");
+		ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
+				   "transaction_write: transaction already"
+				   " prepared, write not allowed");
 		goto fail;
 	}
 
 	/* break it up into block sized chunks */
 	while (len + (off % getpagesize()) > getpagesize()) {
 		tdb_len_t len2 = getpagesize() - (off % getpagesize());
-		if (transaction_write(tdb, off, buf, len2) != 0) {
+		ecode = transaction_write(tdb, off, buf, len2);
+		if (ecode != TDB_SUCCESS) {
 			return -1;
 		}
 		len -= len2;
@@ -207,7 +212,7 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 	}
 
 	if (len == 0) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	blk = off / getpagesize();
@@ -225,8 +230,9 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 				(blk+1)*sizeof(uint8_t *));
 		}
 		if (new_blocks == NULL) {
-			tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
-				   "transaction_write: failed to allocate");
+			ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+					   "transaction_write:"
+					   " failed to allocate");
 			goto fail;
 		}
 		memset(&new_blocks[tdb->transaction->num_blocks], 0,
@@ -240,8 +246,9 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 	if (tdb->transaction->blocks[blk] == NULL) {
 		tdb->transaction->blocks[blk] = (uint8_t *)calloc(getpagesize(), 1);
 		if (tdb->transaction->blocks[blk] == NULL) {
-			tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
-				   "transaction_write: failed to allocate");
+			ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+					   "transaction_write:"
+					   " failed to allocate");
 			goto fail;
 		}
 		if (tdb->transaction->old_map_size > blk * getpagesize()) {
@@ -249,13 +256,17 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 			if (len2 + (blk * getpagesize()) > tdb->transaction->old_map_size) {
 				len2 = tdb->transaction->old_map_size - (blk * getpagesize());
 			}
-			if (tdb->transaction->io_methods->read(tdb, blk * getpagesize(),
-							       tdb->transaction->blocks[blk],
-							       len2) != 0) {
-				tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
-					   "transaction_write: failed to"
-					   " read old block: %s",
-					   strerror(errno));
+			ecode = tdb->transaction->io_methods->tread(tdb,
+					blk * getpagesize(),
+					tdb->transaction->blocks[blk],
+					len2);
+			if (ecode != TDB_SUCCESS) {
+				ecode = tdb_logerr(tdb, ecode,
+						   TDB_LOG_ERROR,
+						   "transaction_write:"
+						   " failed to"
+						   " read old block: %s",
+						   strerror(errno));
 				SAFE_FREE(tdb->transaction->blocks[blk]);
 				goto fail;
 			}
@@ -277,16 +288,16 @@ static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
 		}
 	}
 
-	return 0;
+	return TDB_SUCCESS;
 
 fail:
 	tdb->transaction->transaction_error = 1;
-	return -1;
+	return ecode;
 }
 
 
 /*
-  write while in a transaction - this varient never expands the transaction blocks, it only
+  write while in a transaction - this variant never expands the transaction blocks, it only
   updates existing blocks. This means it cannot change the recovery size
 */
 static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
@@ -333,37 +344,40 @@ static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
 /*
   out of bounds check during a transaction
 */
-static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
+static enum TDB_ERROR transaction_oob(struct tdb_context *tdb, tdb_off_t len,
+				      bool probe)
 {
 	if (len <= tdb->map_size) {
-		return 0;
+		return TDB_SUCCESS;
 	}
-	tdb->ecode = TDB_ERR_IO;
 	if (!probe) {
-		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
+		tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 			   "tdb_oob len %lld beyond transaction size %lld",
 			   (long long)len,
 			   (long long)tdb->map_size);
 	}
-	return -1;
+	return TDB_ERR_IO;
 }
 
 /*
   transaction version of tdb_expand().
 */
-static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t addition)
+static enum TDB_ERROR transaction_expand_file(struct tdb_context *tdb,
+					      tdb_off_t addition)
 {
+	enum TDB_ERROR ecode;
+
 	/* add a write to the transaction elements, so subsequent
 	   reads see the zero data */
-	if (transaction_write(tdb, tdb->map_size, NULL, addition) != 0) {
-		return -1;
+	ecode = transaction_write(tdb, tdb->map_size, NULL, addition);
+	if (ecode == TDB_SUCCESS) {
+		tdb->map_size += addition;
 	}
-	tdb->map_size += addition;
-	return 0;
+	return ecode;
 }
 
 static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
-				size_t len, bool write)
+				size_t len, bool write_mode)
 {
 	size_t blk = off / getpagesize(), end_blk;
 
@@ -371,7 +385,7 @@ static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
 	end_blk = (off + len - 1) / getpagesize();
 
 	/* Can only do direct if in single block and we've already copied. */
-	if (write) {
+	if (write_mode) {
 		if (blk != end_blk)
 			return NULL;
 		if (blk >= tdb->transaction->num_blocks)
@@ -395,7 +409,7 @@ static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
 			return NULL;
 		blk++;
 	}
-	return tdb->transaction->io_methods->direct(tdb, off, len, write);
+	return tdb->transaction->io_methods->direct(tdb, off, len, false);
 }
 
 static const struct tdb_methods transaction_methods = {
@@ -409,40 +423,40 @@ static const struct tdb_methods transaction_methods = {
 /*
   sync to disk
 */
-static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length)
+static enum TDB_ERROR transaction_sync(struct tdb_context *tdb,
+				       tdb_off_t offset, tdb_len_t length)
 {
 	if (tdb->flags & TDB_NOSYNC) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	if (fsync(tdb->fd) != 0) {
-		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-			   "tdb_transaction: fsync failed: %s",
-			   strerror(errno));
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+				  "tdb_transaction: fsync failed: %s",
+				  strerror(errno));
 	}
 #ifdef MS_SYNC
 	if (tdb->map_ptr) {
 		tdb_off_t moffset = offset & ~(getpagesize()-1);
 		if (msync(moffset + (char *)tdb->map_ptr,
 			  length + (offset - moffset), MS_SYNC) != 0) {
-			tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_FATAL,
-				   "tdb_transaction: msync failed: %s",
-				   strerror(errno));
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+					  "tdb_transaction: msync failed: %s",
+					  strerror(errno));
 		}
 	}
 #endif
-	return 0;
+	return TDB_SUCCESS;
 }
 
 
 static void _tdb_transaction_cancel(struct tdb_context *tdb)
 {
 	int i;
+	enum TDB_ERROR ecode;
 
 	if (tdb->transaction == NULL) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
+		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
 			   "tdb_transaction_cancel: no transaction");
 		return;
 	}
@@ -468,11 +482,14 @@ static void _tdb_transaction_cancel(struct tdb_context *tdb)
 		uint64_t invalid = TDB_RECOVERY_INVALID_MAGIC;
 
 		/* remove the recovery marker */
-		if (methods->write(tdb, tdb->transaction->magic_offset,
-				   &invalid, sizeof(invalid)) == -1 ||
-		    transaction_sync(tdb, tdb->transaction->magic_offset,
-				     sizeof(invalid)) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
+		ecode = methods->twrite(tdb, tdb->transaction->magic_offset,
+					&invalid, sizeof(invalid));
+		if (ecode == TDB_SUCCESS)
+			ecode = transaction_sync(tdb,
+						 tdb->transaction->magic_offset,
+						 sizeof(invalid));
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				   "tdb_transaction_cancel: failed to remove"
 				   " recovery magic");
 		}
@@ -496,54 +513,54 @@ static void _tdb_transaction_cancel(struct tdb_context *tdb)
   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)
+enum TDB_ERROR tdb_transaction_start(struct tdb_context *tdb)
 {
+	enum TDB_ERROR ecode;
+
 	/* some sanity checks */
 	if (tdb->read_only || (tdb->flags & TDB_INTERNAL)) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
-			   "tdb_transaction_start: cannot start a transaction"
-			   " on a read-only or internal db");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_start: cannot start a"
+				  " transaction on a read-only or internal db");
 	}
 
 	/* cope with nested tdb_transaction_start() calls */
 	if (tdb->transaction != NULL) {
-		tdb_logerr(tdb, TDB_ERR_NESTING, TDB_DEBUG_ERROR,
-			   "tdb_transaction_start:"
-			   " already inside transaction");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_start:"
+				  " already inside transaction");
 	}
 
 	if (tdb_has_hash_locks(tdb)) {
 		/* 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_logerr(tdb, TDB_ERR_LOCK, TDB_DEBUG_ERROR,
-			   "tdb_transaction_start: cannot start a transaction"
-			   " with locks held");
-		return -1;
+		   of nested locks in POSIX */
+		return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_start: cannot start a"
+				  " transaction with locks held");
 	}
 
 	tdb->transaction = (struct tdb_transaction *)
 		calloc(sizeof(struct tdb_transaction), 1);
 	if (tdb->transaction == NULL) {
-		tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_ERROR,
-			   "tdb_transaction_start: cannot allocate");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+				  "tdb_transaction_start: cannot allocate");
 	}
 
 	/* 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) {
+	ecode = tdb_transaction_lock(tdb, F_WRLCK);
+	if (ecode != TDB_SUCCESS) {
 		SAFE_FREE(tdb->transaction->blocks);
 		SAFE_FREE(tdb->transaction);
-		return -1;
+		return ecode;
 	}
 
 	/* get a read lock over entire file. This is upgraded to a write
 	   lock during the commit */
-	if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true) == -1) {
+	ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true);
+	if (ecode != TDB_SUCCESS) {
 		goto fail_allrecord_lock;
 	}
 
@@ -556,13 +573,13 @@ int tdb_transaction_start(struct tdb_context *tdb)
 	   transaction specific methods */
 	tdb->transaction->io_methods = tdb->methods;
 	tdb->methods = &transaction_methods;
-	return 0;
+	return TDB_SUCCESS;
 
 fail_allrecord_lock:
 	tdb_transaction_unlock(tdb, F_WRLCK);
 	SAFE_FREE(tdb->transaction->blocks);
 	SAFE_FREE(tdb->transaction);
-	return -1;
+	return ecode;
 }
 
 
@@ -605,30 +622,30 @@ static tdb_len_t tdb_recovery_size(struct tdb_context *tdb)
   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)
+static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
+					    tdb_len_t *recovery_size,
+					    tdb_off_t *recovery_offset,
+					    tdb_len_t *recovery_max_size)
 {
 	struct tdb_recovery_record rec;
 	const struct tdb_methods *methods = tdb->transaction->io_methods;
 	tdb_off_t recovery_head;
 	size_t addition;
+	enum TDB_ERROR ecode;
 
 	recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
-	if (recovery_head == TDB_OFF_ERR) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_recovery_allocate:"
-			 " failed to read recovery head");
-		return -1;
+	if (TDB_OFF_IS_ERR(recovery_head)) {
+		return tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
+				  "tdb_recovery_allocate:"
+				  " failed to read recovery head");
 	}
 
 	if (recovery_head != 0) {
-		if (methods->read(tdb, recovery_head, &rec, sizeof(rec))) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-				 "tdb_recovery_allocate:"
-				 " failed to read recovery record");
-			return -1;
+		ecode = methods->tread(tdb, recovery_head, &rec, sizeof(rec));
+		if (ecode != TDB_SUCCESS) {
+			return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+					  "tdb_recovery_allocate:"
+					  " failed to read recovery record");
 		}
 		tdb_convert(tdb, &rec, sizeof(rec));
 		/* ignore invalid recovery regions: can happen in crash */
@@ -644,7 +661,7 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 		/* it fits in the existing area */
 		*recovery_max_size = rec.max_len;
 		*recovery_offset = recovery_head;
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	/* we need to free up the old recovery area, then allocate a
@@ -654,12 +671,13 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	   the transaction) */
 	if (recovery_head != 0) {
 		add_stat(tdb, frees, 1);
-		if (add_free_record(tdb, recovery_head,
-				    sizeof(rec) + rec.max_len) != 0) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-				   "tdb_recovery_allocate:"
-				   " failed to free previous recovery area");
-			return -1;
+		ecode = add_free_record(tdb, recovery_head,
+					sizeof(rec) + rec.max_len);
+		if (ecode != TDB_SUCCESS) {
+			return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+					  "tdb_recovery_allocate:"
+					  " failed to free previous"
+					  " recovery area");
 		}
 	}
 
@@ -681,11 +699,11 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	addition = (tdb->map_size - tdb->transaction->old_map_size) +
 		sizeof(rec) + *recovery_max_size;
 	tdb->map_size = tdb->transaction->old_map_size;
-	if (methods->expand_file(tdb, addition) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_recovery_allocate:"
-			 " failed to create recovery area");
-		return -1;
+	ecode = methods->expand_file(tdb, addition);
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_recovery_allocate:"
+				  " failed to create recovery area");
 	}
 
 	/* we have to reset the old map size so that we don't try to
@@ -696,17 +714,17 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 	/* 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 */
 	tdb_convert(tdb, &recovery_head, sizeof(recovery_head));
-	if (methods->write(tdb, offsetof(struct tdb_header, recovery),
-			   &recovery_head, sizeof(tdb_off_t)) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_recovery_allocate:"
-			 " failed to write recovery head");
-		return -1;
+	ecode = methods->twrite(tdb, offsetof(struct tdb_header, recovery),
+				&recovery_head, sizeof(tdb_off_t));
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_recovery_allocate:"
+				  " failed to write recovery head");
 	}
 	transaction_write_existing(tdb, offsetof(struct tdb_header, recovery),
 				   &recovery_head,
 				   sizeof(tdb_off_t));
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /* Set up header for the recovery record. */
@@ -724,31 +742,34 @@ static void set_recovery_header(struct tdb_recovery_record *rec,
 /*
   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)
+static enum TDB_ERROR transaction_setup_recovery(struct tdb_context *tdb,
+						 tdb_off_t *magic_offset)
 {
-	tdb_len_t recovery_size;
+	/* Initialized for GCC's 4.4.5 overzealous uninitialized warnings. */
+	tdb_len_t recovery_size = 0;
+	tdb_off_t recovery_offset = 0, recovery_max_size = 0;
 	unsigned char *data, *p;
 	const struct tdb_methods *methods = tdb->transaction->io_methods;
 	struct tdb_recovery_record *rec;
-	tdb_off_t recovery_offset, recovery_max_size;
 	tdb_off_t old_map_size = tdb->transaction->old_map_size;
 	uint64_t magic, tailer;
 	int i;
+	enum TDB_ERROR ecode;
 
 	/*
 	  check that the recovery area has enough space
 	*/
-	if (tdb_recovery_allocate(tdb, &recovery_size,
-				  &recovery_offset, &recovery_max_size) == -1) {
-		return -1;
+	ecode = tdb_recovery_allocate(tdb, &recovery_size,
+				      &recovery_offset, &recovery_max_size);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
 	data = (unsigned char *)malloc(recovery_size + sizeof(*rec));
 	if (data == NULL) {
-		tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
-			   "transaction_setup_recovery: cannot allocate");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+				  "transaction_setup_recovery:"
+				  " cannot allocate");
 	}
 
 	rec = (struct tdb_recovery_record *)data;
@@ -777,11 +798,11 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 			continue;
 		}
 		if (offset + length > tdb->map_size) {
-			tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_FATAL,
-				   "tdb_transaction_setup_recovery:"
-				   " transaction data over new region boundary");
 			free(data);
-			return -1;
+			return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+					  "tdb_transaction_setup_recovery:"
+					  " transaction data over new region"
+					  " boundary");
 		}
 		memcpy(p, &offset, sizeof(offset));
 		memcpy(p + sizeof(offset), &length, sizeof(length));
@@ -790,11 +811,12 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 		/* 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->read(tdb, offset,
-				  p + sizeof(offset) + sizeof(length),
-				  length) != 0) {
+		ecode = methods->tread(tdb, offset,
+				       p + sizeof(offset) + sizeof(length),
+				       length);
+		if (ecode != TDB_SUCCESS) {
 			free(data);
-			return -1;
+			return ecode;
 		}
 		p += sizeof(offset) + sizeof(length) + length;
 	}
@@ -805,13 +827,13 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	tdb_convert(tdb, p, sizeof(tailer));
 
 	/* write the recovery data to the recovery area */
-	if (methods->write(tdb, recovery_offset, data,
-			   sizeof(*rec) + recovery_size) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_transaction_setup_recovery:"
-			 " failed to write recovery data");
+	ecode = methods->twrite(tdb, recovery_offset, data,
+				sizeof(*rec) + recovery_size);
+	if (ecode != TDB_SUCCESS) {
 		free(data);
-		return -1;
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_setup_recovery:"
+				  " failed to write recovery data");
 	}
 	transaction_write_existing(tdb, recovery_offset, data,
 				   sizeof(*rec) + recovery_size);
@@ -819,10 +841,11 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	/* 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) {
+	ecode = transaction_sync(tdb, recovery_offset,
+				 sizeof(*rec) + recovery_size);
+	if (ecode != TDB_SUCCESS) {
 		free(data);
-		return -1;
+		return ecode;
 	}
 
 	free(data);
@@ -833,89 +856,89 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
 	*magic_offset = recovery_offset + offsetof(struct tdb_recovery_record,
 						   magic);
 
-	if (methods->write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_transaction_setup_recovery:"
-			 " failed to write recovery magic");
-		return -1;
+	ecode = methods->twrite(tdb, *magic_offset, &magic, sizeof(magic));
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_setup_recovery:"
+				  " failed to write recovery magic");
 	}
 	transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic));
 
 	/* ensure the recovery magic marker is on disk */
-	if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) {
-		return -1;
-	}
-
-	return 0;
+	return transaction_sync(tdb, *magic_offset, sizeof(magic));
 }
 
-static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
+static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 {
 	const struct tdb_methods *methods;
+	enum TDB_ERROR ecode;
 
 	if (tdb->transaction == NULL) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
-			   "tdb_transaction_prepare_commit: no transaction");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_prepare_commit:"
+				  " no transaction");
 	}
 
 	if (tdb->transaction->prepared) {
 		_tdb_transaction_cancel(tdb);
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
-			   "tdb_transaction_prepare_commit:"
-			   " transaction already prepared");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_prepare_commit:"
+				  " transaction already prepared");
 	}
 
 	if (tdb->transaction->transaction_error) {
 		_tdb_transaction_cancel(tdb);
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
-			   "tdb_transaction_prepare_commit:"
-			   " transaction error pending");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_ERROR,
+				  "tdb_transaction_prepare_commit:"
+				  " transaction error pending");
 	}
 
 
 	if (tdb->transaction->nesting != 0) {
 		tdb->transaction->nesting--;
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	/* check for a null transaction */
 	if (tdb->transaction->blocks == NULL) {
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	methods = tdb->transaction->io_methods;
 
 	/* upgrade the main transaction lock region to a write lock */
-	if (tdb_allrecord_upgrade(tdb) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
+	ecode = tdb_allrecord_upgrade(tdb);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 			 "tdb_transaction_prepare_commit:"
 			 " failed to upgrade hash locks");
 		_tdb_transaction_cancel(tdb);
-		return -1;
+		return ecode;
 	}
 
 	/* get the open lock - this prevents new users attaching to the database
 	   during the commit */
-	if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
-			 "tdb_transaction_prepare_commit:"
-			 " failed to get open lock");
+	ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
+	if (ecode != TDB_SUCCESS) {
+		tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+			   "tdb_transaction_prepare_commit:"
+			   " failed to get open lock");
 		_tdb_transaction_cancel(tdb);
-		return -1;
+		return ecode;
 	}
 
 	/* Since we have whole db locked, we don't need the expansion lock. */
 	if (!(tdb->flags & TDB_NOSYNC)) {
 		/* write the recovery data to the end of the file */
-		if (transaction_setup_recovery(tdb, &tdb->transaction->magic_offset) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
+		ecode = transaction_setup_recovery(tdb,
+						   &tdb->transaction
+						   ->magic_offset);
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				 "tdb_transaction_prepare_commit:"
 				 " failed to setup recovery data");
 			_tdb_transaction_cancel(tdb);
-			return -1;
+			return ecode;
 		}
 	}
 
@@ -926,24 +949,24 @@ static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 		tdb_len_t add = tdb->map_size - tdb->transaction->old_map_size;
 		/* Restore original map size for tdb_expand_file */
 		tdb->map_size = tdb->transaction->old_map_size;
-		if (methods->expand_file(tdb, add) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_ERROR,
+		ecode = methods->expand_file(tdb, add);
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				 "tdb_transaction_prepare_commit:"
 				 " expansion failed");
 			_tdb_transaction_cancel(tdb);
-			return -1;
+			return ecode;
 		}
 	}
 
 	/* Keep the open lock until the actual commit */
-
-	return 0;
+	return TDB_SUCCESS;
 }
 
 /*
    prepare to commit the current transaction
 */
-int tdb_transaction_prepare_commit(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_prepare_commit(struct tdb_context *tdb)
 {
 	return _tdb_transaction_prepare_commit(tdb);
 }
@@ -951,43 +974,34 @@ int tdb_transaction_prepare_commit(struct tdb_context *tdb)
 /*
   commit the current transaction
 */
-int tdb_transaction_commit(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb)
 {
 	const struct tdb_methods *methods;
 	int i;
+	enum TDB_ERROR ecode;
 
 	if (tdb->transaction == NULL) {
-		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_DEBUG_ERROR,
-			 "tdb_transaction_commit: no transaction");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+				  "tdb_transaction_commit: no transaction");
 	}
 
 	tdb_trace(tdb, "tdb_transaction_commit");
 
-	if (tdb->transaction->transaction_error) {
-		tdb_transaction_cancel(tdb);
-		tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
-			   "tdb_transaction_commit:"
-			   " transaction error pending");
-		return -1;
-	}
-
-
 	if (tdb->transaction->nesting != 0) {
 		tdb->transaction->nesting--;
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	/* check for a null transaction */
 	if (tdb->transaction->blocks == NULL) {
 		_tdb_transaction_cancel(tdb);
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	if (!tdb->transaction->prepared) {
-		int ret = _tdb_transaction_prepare_commit(tdb);
-		if (ret)
-			return ret;
+		ecode = _tdb_transaction_prepare_commit(tdb);
+		if (ecode != TDB_SUCCESS)
+			return ecode;
 	}
 
 	methods = tdb->transaction->io_methods;
@@ -1007,9 +1021,10 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 			length = tdb->transaction->last_block_size;
 		}
 
-		if (methods->write(tdb, offset, tdb->transaction->blocks[i],
-				   length) == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
+		ecode = methods->twrite(tdb, offset,
+					tdb->transaction->blocks[i], length);
+		if (ecode != TDB_SUCCESS) {
+			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				   "tdb_transaction_commit:"
 				   " write failed during commit");
 
@@ -1021,7 +1036,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 
 			_tdb_transaction_cancel(tdb);
 
-			return -1;
+			return ecode;
 		}
 		SAFE_FREE(tdb->transaction->blocks[i]);
 	}
@@ -1030,8 +1045,9 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 	tdb->transaction->num_blocks = 0;
 
 	/* ensure the new data is on disk */
-	if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
-		return -1;
+	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
 	/*
@@ -1053,7 +1069,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 	   transaction locks */
 	_tdb_transaction_cancel(tdb);
 
-	return 0;
+	return TDB_SUCCESS;
 }
 
 
@@ -1062,63 +1078,61 @@ int tdb_transaction_commit(struct tdb_context *tdb)
   database write access already established (including the open
   lock to prevent new processes attaching)
 */
-int tdb_transaction_recover(struct tdb_context *tdb)
+enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb)
 {
 	tdb_off_t recovery_head, recovery_eof;
 	unsigned char *data, *p;
 	struct tdb_recovery_record rec;
+	enum TDB_ERROR ecode;
 
 	/* find the recovery area */
 	recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
-	if (recovery_head == TDB_OFF_ERR) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_transaction_recover:"
-			 " failed to read recovery head");
-		return -1;
+	if (TDB_OFF_IS_ERR(recovery_head)) {
+		return tdb_logerr(tdb, recovery_head, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to read recovery head");
 	}
 
 	if (recovery_head == 0) {
 		/* we have never allocated a recovery record */
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	/* read the recovery record */
-	if (tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec)) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			   "tdb_transaction_recover:"
-			   " failed to read recovery record");
-		return -1;
+	ecode = tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec));
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to read recovery record");
 	}
 
 	if (rec.magic != TDB_RECOVERY_MAGIC) {
 		/* there is no valid recovery data */
-		return 0;
+		return TDB_SUCCESS;
 	}
 
 	if (tdb->read_only) {
-		tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_DEBUG_FATAL,
-			   "tdb_transaction_recover:"
-			   " attempt to recover read only database");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " attempt to recover read only database");
 	}
 
 	recovery_eof = rec.eof;
 
 	data = (unsigned char *)malloc(rec.len);
 	if (data == NULL) {
-		tdb_logerr(tdb, TDB_ERR_OOM, TDB_DEBUG_FATAL,
-			   "tdb_transaction_recover:"
-			   " failed to allocate recovery data");
-		return -1;
+		return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to allocate recovery data");
 	}
 
 	/* read the full recovery data */
-	if (tdb->methods->read(tdb, recovery_head + sizeof(rec), data,
-			       rec.len) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			   "tdb_transaction_recover:"
-			   " failed to read recovery data");
-		return -1;
+	ecode = tdb->methods->tread(tdb, recovery_head + sizeof(rec), data,
+				    rec.len);
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to read recovery data");
 	}
 
 	/* recover the file data */
@@ -1131,71 +1145,75 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 		memcpy(&len, p + sizeof(ofs), sizeof(len));
 		p += sizeof(ofs) + sizeof(len);
 
-		if (tdb->methods->write(tdb, ofs, p, len) == -1) {
+		ecode = tdb->methods->twrite(tdb, ofs, p, len);
+		if (ecode != TDB_SUCCESS) {
 			free(data);
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-				 "tdb_transaction_recover:"
-				 " failed to recover %zu bytes at offset %zu",
-				 (size_t)len, (size_t)ofs);
-			return -1;
+			return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+					  "tdb_transaction_recover:"
+					  " failed to recover %zu bytes"
+					  " at offset %zu",
+					  (size_t)len, (size_t)ofs);
 		}
 		p += len;
 	}
 
 	free(data);
 
-	if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			   "tdb_transaction_recover: failed to sync recovery");
-		return -1;
+	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to sync recovery");
 	}
 
 	/* if the recovery area is after the recovered eof then remove it */
 	if (recovery_eof <= recovery_head) {
-		if (tdb_write_off(tdb, offsetof(struct tdb_header,recovery), 0)
-		    == -1) {
-			tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-				 "tdb_transaction_recover:"
-				 " failed to remove recovery head");
-			return -1;
+		ecode = tdb_write_off(tdb, offsetof(struct tdb_header,
+						    recovery),
+				      0);
+		if (ecode != TDB_SUCCESS) {
+			return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+					  "tdb_transaction_recover:"
+					  " failed to remove recovery head");
 		}
 	}
 
 	/* remove the recovery magic */
-	if (tdb_write_off(tdb,
-			  recovery_head
-			  + offsetof(struct tdb_recovery_record, magic),
-			  TDB_RECOVERY_INVALID_MAGIC) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_transaction_recover:"
-			 " failed to remove recovery magic");
-		return -1;
+	ecode = tdb_write_off(tdb,
+			      recovery_head
+			      + offsetof(struct tdb_recovery_record, magic),
+			      TDB_RECOVERY_INVALID_MAGIC);
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to remove recovery magic");
 	}
 
-	if (transaction_sync(tdb, 0, recovery_eof) == -1) {
-		tdb_logerr(tdb, tdb->ecode, TDB_DEBUG_FATAL,
-			 "tdb_transaction_recover: failed to sync2 recovery");
-		return -1;
+	ecode = transaction_sync(tdb, 0, recovery_eof);
+	if (ecode != TDB_SUCCESS) {
+		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
+				  "tdb_transaction_recover:"
+				  " failed to sync2 recovery");
 	}
 
-	tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
+	tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
 		   "tdb_transaction_recover: recovered %zu byte database",
 		   (size_t)recovery_eof);
 
 	/* all done */
-	return 0;
+	return TDB_SUCCESS;
 }
 
-/* Any I/O failures we say "needs recovery". */
-bool tdb_needs_recovery(struct tdb_context *tdb)
+tdb_bool_err tdb_needs_recovery(struct tdb_context *tdb)
 {
 	tdb_off_t recovery_head;
 	struct tdb_recovery_record rec;
+	enum TDB_ERROR ecode;
 
 	/* find the recovery area */
 	recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
-	if (recovery_head == TDB_OFF_ERR) {
-		return true;
+	if (TDB_OFF_IS_ERR(recovery_head)) {
+		return recovery_head;
 	}
 
 	if (recovery_head == 0) {
@@ -1204,8 +1222,9 @@ bool tdb_needs_recovery(struct tdb_context *tdb)
 	}
 
 	/* read the recovery record */
-	if (tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec)) == -1) {
-		return true;
+	ecode = tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec));
+	if (ecode != TDB_SUCCESS) {
+		return ecode;
 	}
 
 	return (rec.magic == TDB_RECOVERY_MAGIC);