Use _ convention everywhere: lock.c uses it already.

[ccan] / ccan / tdb / transaction.c

diff --git a/ccan/tdb/transaction.c b/ccan/tdb/transaction.c
index 6909c261a2808ca50c33cb413a5597cde8d4cbd5..7e8ac34dd5bc7e93a9a20cd9ac7e127716d3e504 100644 (file)
--- a/ccan/tdb/transaction.c
+++ b/ccan/tdb/transaction.c
@@ -85,11 +85,13 @@
     still available, but no transaction recovery area is used and no
     fsync/msync calls are made.
 
-  - if TDB_NO_NESTING is passed to flags in tdb open then transaction
-    nesting is disabled. tdb_transaction_start() will then implicitely
-    cancel any pending transactions and always start a new transaction
-    context instead of nesting.
+  - if TDB_ALLOW_NESTING is passed to flags in tdb open, or added using
+    tdb_add_flags() transaction is enabled.
+    The default is that transaction nesting is not allowed and an attempt
+    to create a nested transaction will fail with TDB_ERR_NESTING.
 
+    Beware. when transactions are nested a transaction successfully
+    completed with tdb_transaction_commit() can be silently unrolled later.
 */
 
 
@@ -453,7 +455,7 @@ static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t
        return 0;
 }
 
-int tdb_transaction_cancel_internal(struct tdb_context *tdb)
+int _tdb_transaction_cancel(struct tdb_context *tdb)
 {
        int i, ret = 0;
 
@@ -533,16 +535,15 @@ int tdb_transaction_start(struct tdb_context *tdb)
 
        /* cope with nested tdb_transaction_start() calls */
        if (tdb->transaction != NULL) {
-               tdb_trace(tdb, "tdb_transaction_start");
-               if (!tdb->flags & TDB_NO_NESTING) {
-                       tdb->transaction->nesting++;
-                       TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: nesting %d\n", 
-                                tdb->transaction->nesting));
-                       return 0;
-               } else {
-                       tdb_transaction_cancel_internal(tdb);
-                       TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: cancelling previous transaction\n"));
+               if (!(tdb->flags & TDB_ALLOW_NESTING)) {
+                       tdb->ecode = TDB_ERR_NESTING;
+                       return -1;
                }
+               tdb_trace(tdb, "tdb_transaction_start");
+               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) {
@@ -635,7 +636,7 @@ fail:
 int tdb_transaction_cancel(struct tdb_context *tdb)
 {      
        tdb_trace(tdb, "tdb_transaction_cancel");
-       return tdb_transaction_cancel_internal(tdb);
+       return _tdb_transaction_cancel(tdb);
 }
 
 /*
@@ -884,7 +885,7 @@ static int transaction_setup_recovery(struct tdb_context *tdb,
        return 0;
 }
 
-static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
+static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 {      
        const struct tdb_methods *methods;
 
@@ -895,14 +896,14 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
 
        if (tdb->transaction->prepared) {
                tdb->ecode = TDB_ERR_EINVAL;
-               tdb_transaction_cancel(tdb);
+               _tdb_transaction_cancel(tdb);
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: transaction already prepared\n"));
                return -1;
        }
 
        if (tdb->transaction->transaction_error) {
                tdb->ecode = TDB_ERR_IO;
-               tdb_transaction_cancel_internal(tdb);
+               _tdb_transaction_cancel(tdb);
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: transaction error pending\n"));
                return -1;
        }
@@ -930,7 +931,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
        if (tdb->num_locks || tdb->global_lock.count) {
                tdb->ecode = TDB_ERR_LOCK;
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: locks pending on commit\n"));
-               tdb_transaction_cancel_internal(tdb);
+               _tdb_transaction_cancel(tdb);
                return -1;
        }
 
@@ -938,7 +939,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
        if (tdb_brlock_upgrade(tdb, FREELIST_TOP, 0) == -1) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: failed to upgrade hash locks\n"));
                tdb->ecode = TDB_ERR_LOCK;
-               tdb_transaction_cancel_internal(tdb);
+               _tdb_transaction_cancel(tdb);
                return -1;
        }
 
@@ -947,7 +948,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
        if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: failed to get global lock\n"));
                tdb->ecode = TDB_ERR_LOCK;
-               tdb_transaction_cancel_internal(tdb);
+               _tdb_transaction_cancel(tdb);
                return -1;
        }
 
@@ -956,7 +957,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
                if (transaction_setup_recovery(tdb, &tdb->transaction->magic_offset) == -1) {
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_prepare_commit: failed to setup recovery data\n"));
                        tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-                       tdb_transaction_cancel_internal(tdb);
+                       _tdb_transaction_cancel(tdb);
                        return -1;
                }
        }
@@ -971,7 +972,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
                        tdb->ecode = TDB_ERR_IO;
                        TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_prepare_commit: expansion failed\n"));
                        tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1);
-                       tdb_transaction_cancel_internal(tdb);
+                       _tdb_transaction_cancel(tdb);
                        return -1;
                }
                tdb->map_size = tdb->transaction->old_map_size;
@@ -989,7 +990,7 @@ static int tdb_transaction_prepare_commit_internal(struct tdb_context *tdb)
 int tdb_transaction_prepare_commit(struct tdb_context *tdb)
 {      
        tdb_trace(tdb, "tdb_transaction_prepare_commit");
-       return tdb_transaction_prepare_commit_internal(tdb);
+       return _tdb_transaction_prepare_commit(tdb);
 }
 
 /*
@@ -1029,12 +1030,12 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 
        /* check for a null transaction */
        if (tdb->transaction->blocks == NULL) {
-               tdb_transaction_cancel_internal(tdb);
+               _tdb_transaction_cancel(tdb);
                return 0;
        }
 
        if (!tdb->transaction->prepared) {
-               int ret = tdb_transaction_prepare_commit_internal(tdb);
+               int ret = _tdb_transaction_prepare_commit(tdb);
                if (ret)
                        return ret;
        }
@@ -1065,7 +1066,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
                        tdb->methods = methods;
                        tdb_transaction_recover(tdb); 
 
-                       tdb_transaction_cancel_internal(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"));
@@ -1103,7 +1104,7 @@ int tdb_transaction_commit(struct tdb_context *tdb)
 
        /* use a transaction cancel to free memory and remove the
           transaction locks */
-       tdb_transaction_cancel_internal(tdb);
+       _tdb_transaction_cancel(tdb);
 
        if (need_repack) {
                return tdb_repack(tdb);