X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Ftransaction.c;h=73ab1e39ff4ad0c4f260be0bf1dc6d9eca95bcd2;hp=66565d67c2d762b67cba9169ee3d9f8f661b78d3;hb=41e027e11e0b15100e50c14e49aaa4c2b418f431;hpb=3d917ba6dffe2029608a3d4c870dfdb4033ca4c9

diff --git a/ccan/tdb2/transaction.c b/ccan/tdb2/transaction.c
index 66565d67..73ab1e39 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
@@ -297,7 +297,7 @@ fail:
 
 
 /*
-  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,
@@ -347,14 +347,14 @@ static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
 static enum TDB_ERROR transaction_oob(struct tdb_context *tdb, tdb_off_t len,
 				      bool probe)
 {
-	if (len <= tdb->map_size) {
+	if (len <= tdb->file->map_size) {
 		return TDB_SUCCESS;
 	}
 	if (!probe) {
 		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);
+			   (long long)tdb->file->map_size);
 	}
 	return TDB_ERR_IO;
 }
@@ -369,9 +369,9 @@ static enum TDB_ERROR transaction_expand_file(struct tdb_context *tdb,
 
 	/* add a write to the transaction elements, so subsequent
 	   reads see the zero data */
-	ecode = transaction_write(tdb, tdb->map_size, NULL, addition);
+	ecode = transaction_write(tdb, tdb->file->map_size, NULL, addition);
 	if (ecode == TDB_SUCCESS) {
-		tdb->map_size += addition;
+		tdb->file->map_size += addition;
 	}
 	return ecode;
 }
@@ -430,15 +430,15 @@ static enum TDB_ERROR transaction_sync(struct tdb_context *tdb,
 		return TDB_SUCCESS;
 	}
 
-	if (fsync(tdb->fd) != 0) {
+	if (fsync(tdb->file->fd) != 0) {
 		return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 				  "tdb_transaction: fsync failed: %s",
 				  strerror(errno));
 	}
 #ifdef MS_SYNC
-	if (tdb->map_ptr) {
+	if (tdb->file->map_ptr) {
 		tdb_off_t moffset = offset & ~(getpagesize()-1);
-		if (msync(moffset + (char *)tdb->map_ptr,
+		if (msync(moffset + (char *)tdb->file->map_ptr,
 			  length + (offset - moffset), MS_SYNC) != 0) {
 			return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 					  "tdb_transaction: msync failed: %s",
@@ -467,7 +467,7 @@ static void _tdb_transaction_cancel(struct tdb_context *tdb)
 		return;
 	}
 
-	tdb->map_size = tdb->transaction->old_map_size;
+	tdb->file->map_size = tdb->transaction->old_map_size;
 
 	/* free all the transaction blocks */
 	for (i=0;i<tdb->transaction->num_blocks;i++) {
@@ -495,8 +495,8 @@ static void _tdb_transaction_cancel(struct tdb_context *tdb)
 		}
 	}
 
-	if (tdb->allrecord_lock.count)
-		tdb_allrecord_unlock(tdb, tdb->allrecord_lock.ltype);
+	if (tdb->file->allrecord_lock.count)
+		tdb_allrecord_unlock(tdb, tdb->file->allrecord_lock.ltype);
 
 	/* restore the normal io methods */
 	tdb->methods = tdb->transaction->io_methods;
@@ -513,42 +513,38 @@ 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_LOG_USE_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_IO, TDB_LOG_USE_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_LOG_USE_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_LOG_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
@@ -556,36 +552,34 @@ int tdb_transaction_start(struct tdb_context *tdb)
 	   make this async, which we will probably do in the future */
 	ecode = tdb_transaction_lock(tdb, F_WRLCK);
 	if (ecode != TDB_SUCCESS) {
-		tdb->ecode = ecode;
 		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 */
 	ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true);
 	if (ecode != TDB_SUCCESS) {
-		tdb->ecode = ecode;
 		goto fail_allrecord_lock;
 	}
 
 	/* make sure we know about any file expansions already done by
 	   anyone else */
-	tdb->methods->oob(tdb, tdb->map_size + 1, true);
-	tdb->transaction->old_map_size = tdb->map_size;
+	tdb->methods->oob(tdb, tdb->file->map_size + 1, true);
+	tdb->transaction->old_map_size = tdb->file->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;
+	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;
 }
 
 
@@ -695,16 +689,16 @@ static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
 		= (((sizeof(rec) + *recovery_size) + getpagesize()-1)
 		   & ~(getpagesize()-1))
 		- sizeof(rec);
-	*recovery_offset = tdb->map_size;
+	*recovery_offset = tdb->file->map_size;
 	recovery_head = *recovery_offset;
 
 	/* Restore ->map_size before calling underlying expand_file.
 	   Also so that we don't try to expand the file again in the
 	   transaction commit, which would destroy the recovery
 	   area */
-	addition = (tdb->map_size - tdb->transaction->old_map_size) +
+	addition = (tdb->file->map_size - tdb->transaction->old_map_size) +
 		sizeof(rec) + *recovery_max_size;
-	tdb->map_size = tdb->transaction->old_map_size;
+	tdb->file->map_size = tdb->transaction->old_map_size;
 	ecode = methods->expand_file(tdb, addition);
 	if (ecode != TDB_SUCCESS) {
 		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
@@ -715,7 +709,7 @@ static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
 	/* 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;
+	tdb->transaction->old_map_size = tdb->file->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 */
@@ -751,11 +745,12 @@ static void set_recovery_header(struct tdb_recovery_record *rec,
 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;
@@ -802,7 +797,7 @@ static enum TDB_ERROR transaction_setup_recovery(struct tdb_context *tdb,
 		if (offset >= old_map_size) {
 			continue;
 		}
-		if (offset + length > tdb->map_size) {
+		if (offset + length > tdb->file->map_size) {
 			free(data);
 			return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 					  "tdb_transaction_setup_recovery:"
@@ -950,10 +945,12 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 	tdb->transaction->prepared = true;
 
 	/* expand the file to the new size if needed */
-	if (tdb->map_size != tdb->transaction->old_map_size) {
-		tdb_len_t add = tdb->map_size - tdb->transaction->old_map_size;
+	if (tdb->file->map_size != tdb->transaction->old_map_size) {
+		tdb_len_t add;
+
+		add = tdb->file->map_size - tdb->transaction->old_map_size;
 		/* Restore original map size for tdb_expand_file */
-		tdb->map_size = tdb->transaction->old_map_size;
+		tdb->file->map_size = tdb->transaction->old_map_size;
 		ecode = methods->expand_file(tdb, add);
 		if (ecode != TDB_SUCCESS) {
 			tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
@@ -971,46 +968,42 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 /*
    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)
 {
-	tdb->ecode = _tdb_transaction_prepare_commit(tdb);
-	if (tdb->ecode != TDB_SUCCESS)
-		return -1;
-	return 0;
+	return _tdb_transaction_prepare_commit(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_LOG_USE_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->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) {
-		tdb->ecode = _tdb_transaction_prepare_commit(tdb);
-		if (tdb->ecode != TDB_SUCCESS)
-			return -1;
+		ecode = _tdb_transaction_prepare_commit(tdb);
+		if (ecode != TDB_SUCCESS)
+			return ecode;
 	}
 
 	methods = tdb->transaction->io_methods;
@@ -1045,7 +1038,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 
 			_tdb_transaction_cancel(tdb);
 
-			return -1;
+			return ecode;
 		}
 		SAFE_FREE(tdb->transaction->blocks[i]);
 	}
@@ -1054,10 +1047,9 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 	tdb->transaction->num_blocks = 0;
 
 	/* ensure the new data is on disk */
-	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	ecode = transaction_sync(tdb, 0, tdb->file->map_size);
 	if (ecode != TDB_SUCCESS) {
-		tdb->ecode = ecode;
-		return -1;
+		return ecode;
 	}
 
 	/*
@@ -1079,7 +1071,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 	   transaction locks */
 	_tdb_transaction_cancel(tdb);
 
-	return 0;
+	return TDB_SUCCESS;
 }
 
 
@@ -1169,7 +1161,7 @@ enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb)
 
 	free(data);
 
-	ecode = transaction_sync(tdb, 0, tdb->map_size);
+	ecode = transaction_sync(tdb, 0, tdb->file->map_size);
 	if (ecode != TDB_SUCCESS) {
 		return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
 				  "tdb_transaction_recover:"