X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Ftransaction.c;h=c5580f205d39c074fbbe52f9f5545659638112c3;hp=4a49cc7b6421848a0eac1efbff2cb9e4913bb367;hb=176844c84ff5ae6a5f146c5d1b7a3927bd781739;hpb=088b2a9f4a7dedf357d90e5e420062461f78a13b diff --git a/ccan/tdb/transaction.c b/ccan/tdb/transaction.c index 4a49cc7b..c5580f20 100644 --- a/ccan/tdb/transaction.c +++ b/ccan/tdb/transaction.c @@ -86,12 +86,20 @@ fsync/msync calls are made. - 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. + tdb_add_flags() transaction nesting is enabled. + It resets the TDB_DISALLOW_NESTING flag, as both cannot be used together. + The default is that transaction nesting is allowed. + Note: this default may change in future versions of tdb. Beware. when transactions are nested a transaction successfully completed with tdb_transaction_commit() can be silently unrolled later. + + - if TDB_DISALLOW_NESTING is passed to flags in tdb open, or added using + tdb_add_flags() transaction nesting is disabled. + It resets the TDB_ALLOW_NESTING flag, as both cannot be used together. + An attempt create a nested transaction will fail with TDB_ERR_NESTING. + The default is that transaction nesting is allowed. + Note: this default may change in future versions of tdb. */ @@ -127,6 +135,9 @@ struct tdb_transaction { bool prepared; tdb_off_t magic_offset; + /* set when the GLOBAL_LOCK has been taken */ + bool global_lock_taken; + /* old file size before transaction */ tdb_len_t old_map_size; @@ -493,6 +504,11 @@ int _tdb_transaction_cancel(struct tdb_context *tdb, int ltype) } } + if (tdb->transaction->global_lock_taken) { + tdb_brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1); + tdb->transaction->global_lock_taken = false; + } + /* remove any global lock created during the transaction */ if (tdb->global_lock.count != 0) { tdb_brunlock(tdb, tdb->global_lock.ltype, @@ -680,7 +696,7 @@ static int tdb_recovery_allocate(struct tdb_context *tdb, tdb_off_t *recovery_offset, tdb_len_t *recovery_max_size) { - struct list_struct rec; + struct tdb_record rec; const struct tdb_methods *methods = tdb->transaction->io_methods; tdb_off_t recovery_head; @@ -766,7 +782,7 @@ static int transaction_setup_recovery(struct tdb_context *tdb, tdb_len_t recovery_size; unsigned char *data, *p; const struct tdb_methods *methods = tdb->transaction->io_methods; - struct list_struct *rec; + struct tdb_record *rec; tdb_off_t recovery_offset, recovery_max_size; tdb_off_t old_map_size = tdb->transaction->old_map_size; uint32_t magic, tailer; @@ -786,7 +802,7 @@ static int transaction_setup_recovery(struct tdb_context *tdb, return -1; } - rec = (struct list_struct *)data; + rec = (struct tdb_record *)data; memset(rec, 0, sizeof(*rec)); rec->magic = 0; @@ -869,7 +885,7 @@ static int transaction_setup_recovery(struct tdb_context *tdb, magic = TDB_RECOVERY_MAGIC; CONVERT(magic); - *magic_offset = recovery_offset + offsetof(struct list_struct, magic); + *magic_offset = recovery_offset + offsetof(struct tdb_record, 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")); @@ -919,11 +935,6 @@ static int _tdb_transaction_prepare_commit(struct tdb_context *tdb) return 0; } -#ifdef TDB_TRACE - /* store seqnum now, before reading becomes illegal. */ - tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &tdb->transaction_prepare_seqnum); -#endif - /* check for a null transaction */ if (tdb->transaction->blocks == NULL) { return 0; @@ -957,11 +968,12 @@ static int _tdb_transaction_prepare_commit(struct tdb_context *tdb) return -1; } + tdb->transaction->global_lock_taken = true; + 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_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_prepare_commit: failed to setup recovery data\n")); - tdb_brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1); _tdb_transaction_cancel(tdb, F_WRLCK); return -1; } @@ -976,7 +988,6 @@ static int _tdb_transaction_prepare_commit(struct tdb_context *tdb) tdb->transaction->old_map_size) == -1) { tdb->ecode = TDB_ERR_IO; TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_prepare_commit: expansion failed\n")); - tdb_brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1); _tdb_transaction_cancel(tdb, F_WRLCK); return -1; } @@ -1012,13 +1023,7 @@ int tdb_transaction_commit(struct tdb_context *tdb) return -1; } - /* If we've prepared, can't read seqnum. */ - if (tdb->transaction->prepared) { - tdb_trace_seqnum(tdb, tdb->transaction_prepare_seqnum, - "tdb_transaction_commit"); - } else { - tdb_trace(tdb, "tdb_transaction_commit"); - } + tdb_trace(tdb, "tdb_transaction_commit"); if (tdb->transaction->transaction_error) { tdb->ecode = TDB_ERR_IO; @@ -1072,7 +1077,6 @@ int tdb_transaction_commit(struct tdb_context *tdb) tdb_transaction_recover(tdb); _tdb_transaction_cancel(tdb, F_WRLCK); - tdb_brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1); TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed\n")); return -1; @@ -1088,8 +1092,6 @@ int tdb_transaction_commit(struct tdb_context *tdb) return -1; } - tdb_brunlock(tdb, F_WRLCK, GLOBAL_LOCK, 1); - /* TODO: maybe write to some dummy hdr field, or write to magic offset without mmap, before the last sync, instead of the @@ -1129,7 +1131,7 @@ 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; + struct tdb_record rec; /* find the recovery area */ if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { @@ -1216,7 +1218,7 @@ int tdb_transaction_recover(struct tdb_context *tdb) } /* remove the recovery magic */ - if (tdb_ofs_write(tdb, recovery_head + offsetof(struct list_struct, magic), + if (tdb_ofs_write(tdb, recovery_head + offsetof(struct tdb_record, magic), &zero) == -1) { TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery magic\n")); tdb->ecode = TDB_ERR_IO;