tdb2: overallocate the recovery area.

[ccan] / ccan / tdb2 / transaction.c

diff --git a/ccan/tdb2/transaction.c b/ccan/tdb2/transaction.c
index 29192beece4e3e48f0a6a337c677af2e14c0de63..a27c027365eec3fc7be001d9693bde42ec6f0b45 100644 (file)
--- a/ccan/tdb2/transaction.c
+++ b/ccan/tdb2/transaction.c
@@ -110,7 +110,7 @@ struct tdb_transaction {
        /* 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;
+       unsigned int nesting;
 
        /* set when a prepare has already occurred */
        bool prepared;
@@ -531,11 +531,15 @@ enum TDB_ERROR tdb_transaction_start(struct tdb_context *tdb)
 
        /* cope with nested tdb_transaction_start() calls */
        if (tdb->transaction != NULL) {
-               return tdb->last_error = tdb_logerr(tdb, TDB_ERR_IO,
-                                                   TDB_LOG_USE_ERROR,
-                                                   "tdb_transaction_start:"
-                                                   " already inside"
-                                                   " transaction");
+               if (!(tdb->flags & TDB_ALLOW_NESTING)) {
+                       return tdb->last_error
+                               = tdb_logerr(tdb, TDB_ERR_IO,
+                                            TDB_LOG_USE_ERROR,
+                                            "tdb_transaction_start:"
+                                            " already inside transaction");
+               }
+               tdb->transaction->nesting++;
+               return 0;
        }
 
        if (tdb_has_hash_locks(tdb)) {
@@ -682,9 +686,10 @@ static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
           us an area that is being currently used (as of the start of
           the transaction) */
        if (recovery_head != 0) {
-               add_stat(tdb, frees, 1);
+               tdb->stats.frees++;
                ecode = add_free_record(tdb, recovery_head,
-                                       sizeof(rec) + rec.max_len);
+                                       sizeof(rec) + rec.max_len,
+                                       TDB_LOCK_WAIT);
                if (ecode != TDB_SUCCESS) {
                        return tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
                                          "tdb_recovery_allocate:"
@@ -696,10 +701,11 @@ static enum TDB_ERROR tdb_recovery_allocate(struct tdb_context *tdb,
        /* the tdb_free() call might have increased the recovery size */
        *recovery_size = tdb_recovery_size(tdb);
 
-       /* round up to a multiple of page size */
+       /* round up to a multiple of page size. Overallocate, since each
+        * such allocation forces us to expand the file. */
        *recovery_max_size
-               = (((sizeof(rec) + *recovery_size) + PAGESIZE-1)
-                  & ~(PAGESIZE-1))
+               = (((sizeof(rec) + *recovery_size + *recovery_size / 2)
+                   + PAGESIZE-1) & ~(PAGESIZE-1))
                - sizeof(rec);
        *recovery_offset = tdb->file->map_size;
        recovery_head = *recovery_offset;
@@ -907,7 +913,6 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
 
 
        if (tdb->transaction->nesting != 0) {
-               tdb->transaction->nesting--;
                return TDB_SUCCESS;
        }
 
@@ -921,10 +926,6 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
        /* upgrade the main transaction lock region to a write lock */
        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 ecode;
        }
 
@@ -932,10 +933,6 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
           during the commit */
        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 ecode;
        }
 
@@ -946,10 +943,6 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *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 ecode;
                }
        }
@@ -965,10 +958,6 @@ static enum TDB_ERROR _tdb_transaction_prepare_commit(struct tdb_context *tdb)
                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,
-                                "tdb_transaction_prepare_commit:"
-                                " expansion failed");
-                       _tdb_transaction_cancel(tdb);
                        return ecode;
                }
        }
@@ -1016,8 +1005,10 @@ enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb)
 
        if (!tdb->transaction->prepared) {
                ecode = _tdb_transaction_prepare_commit(tdb);
-               if (ecode != TDB_SUCCESS)
+               if (ecode != TDB_SUCCESS) {
+                       _tdb_transaction_cancel(tdb);
                        return tdb->last_error = ecode;
+               }
        }
 
        methods = tdb->transaction->io_methods;
@@ -1040,10 +1031,6 @@ enum TDB_ERROR tdb_transaction_commit(struct tdb_context *tdb)
                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");
-
                        /* we've overwritten part of the data and
                           possibly expanded the file, so we need to
                           run the crash recovery code */