to reduce this to 3 or even 2 with some more work.
- check for a valid recovery record on open of the tdb, while the
- global lock is held. Automatically recover from the transaction
+ open lock is held. Automatically recover from the transaction
recovery area if needed, then continue with the open as
usual. This allows for smooth crash recovery with no administrator
intervention.
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;
int rw_type, tdb_off_t offset, size_t len,
enum tdb_lock_flags flags)
{
+ /* FIXME: We actually grab the open lock during a transaction. */
+ if (offset == OPEN_LOCK)
+ return tdb_brlock(tdb, rw_type, offset, len, flags);
return 0;
}
return 0;
}
-/* ltype is F_WRLCK after prepare. */
-int _tdb_transaction_cancel(struct tdb_context *tdb, int ltype)
+
+static int _tdb_transaction_cancel(struct tdb_context *tdb)
{
int i, ret = 0;
if (tdb->transaction->magic_offset) {
const struct tdb_methods *methods = tdb->transaction->io_methods;
- uint32_t zero = 0;
+ uint32_t invalid = TDB_RECOVERY_INVALID_MAGIC;
/* remove the recovery marker */
- if (methods->tdb_write(tdb, tdb->transaction->magic_offset, &zero, 4) == -1 ||
+ if (methods->tdb_write(tdb, tdb->transaction->magic_offset, &invalid, 4) == -1 ||
transaction_sync(tdb, tdb->transaction->magic_offset, 4) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_cancel: failed to remove recovery magic\n"));
ret = -1;
}
}
- 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,
- FREELIST_TOP, 4*tdb->header.hash_size);
- tdb->global_lock.count = 0;
- }
-
- /* remove any locks created during the transaction */
- if (tdb->num_locks != 0) {
- for (i=0;i<tdb->num_lockrecs;i++) {
- tdb_brunlock(tdb, tdb->lockrecs[i].ltype,
- FREELIST_TOP+4*tdb->lockrecs[i].list, 1);
- }
- tdb->num_locks = 0;
- tdb->num_lockrecs = 0;
- SAFE_FREE(tdb->lockrecs);
- }
+ /* This also removes the OPEN_LOCK, if we have it. */
+ tdb_release_extra_locks(tdb);
/* restore the normal io methods */
tdb->methods = tdb->transaction->io_methods;
- tdb_brunlock(tdb, ltype, FREELIST_TOP, 0);
tdb_transaction_unlock(tdb, F_WRLCK);
SAFE_FREE(tdb->transaction->hash_heads);
SAFE_FREE(tdb->transaction);
return 0;
}
- if (tdb->num_locks != 0 || tdb->global_lock.count) {
+ if (tdb_have_extra_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 */
/* get a read lock from the freelist to the end of file. This
is upgraded to a write lock during the commit */
- if (tdb_brlock(tdb, F_RDLCK, FREELIST_TOP, 0, TDB_LOCK_WAIT) == -1) {
+ if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true) == -1) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to get hash locks\n"));
- tdb->ecode = TDB_ERR_LOCK;
- goto fail;
+ goto fail_allrecord_lock;
}
/* setup a copy of the hash table heads so the hash scan in
return 0;
fail:
- tdb_brunlock(tdb, F_RDLCK, FREELIST_TOP, 0);
+ tdb_allrecord_unlock(tdb, F_RDLCK, false);
+fail_allrecord_lock:
tdb_transaction_unlock(tdb, F_WRLCK);
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction->hash_heads);
*/
int tdb_transaction_cancel(struct tdb_context *tdb)
{
- int ltype = F_RDLCK;
tdb_trace(tdb, "tdb_transaction_cancel");
- if (tdb->transaction && tdb->transaction->prepared)
- ltype = F_WRLCK;
- return _tdb_transaction_cancel(tdb, ltype);
+ return _tdb_transaction_cancel(tdb);
}
/*
rec = (struct tdb_record *)data;
memset(rec, 0, sizeof(*rec));
- rec->magic = 0;
+ rec->magic = TDB_RECOVERY_INVALID_MAGIC;
rec->data_len = recovery_size;
rec->rec_len = recovery_max_size;
rec->key_len = old_map_size;
if (tdb->transaction->prepared) {
tdb->ecode = TDB_ERR_EINVAL;
- _tdb_transaction_cancel(tdb, F_WRLCK);
+ _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(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: transaction error pending\n"));
return -1;
}
/* if there are any locks pending then the caller has not
nested their locks properly, so fail the transaction */
- if (tdb->num_locks || tdb->global_lock.count) {
+ if (tdb_have_extra_locks(tdb)) {
tdb->ecode = TDB_ERR_LOCK;
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: locks pending on commit\n"));
- _tdb_transaction_cancel(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
/* upgrade the main transaction lock region to a write lock */
- if (tdb_brlock_upgrade(tdb, FREELIST_TOP, 0) == -1) {
+ if (tdb_allrecord_upgrade(tdb) == -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(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
- /* get the global lock - this prevents new users attaching to the database
+ /* get the open lock - this prevents new users attaching to the database
during the commit */
- if (tdb_brlock(tdb, F_WRLCK, GLOBAL_LOCK, 1, TDB_LOCK_WAIT) == -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(tdb, F_WRLCK);
+ if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
+ TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: failed to get open lock\n"));
+ _tdb_transaction_cancel(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_transaction_cancel(tdb, F_WRLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
}
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_transaction_cancel(tdb, F_WRLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
tdb->map_size = tdb->transaction->old_map_size;
methods->tdb_oob(tdb, tdb->map_size + 1, 1);
}
- /* Keep the global lock until the actual commit */
+ /* Keep the open lock until the actual commit */
return 0;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
- _tdb_transaction_cancel(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
return 0;
}
tdb->methods = methods;
tdb_transaction_recover(tdb);
- _tdb_transaction_cancel(tdb, F_WRLCK);
+ _tdb_transaction_cancel(tdb);
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed\n"));
return -1;
/* use a transaction cancel to free memory and remove the
transaction locks */
- _tdb_transaction_cancel(tdb, F_WRLCK);
+ _tdb_transaction_cancel(tdb);
if (need_repack) {
return tdb_repack(tdb);
/*
recover from an aborted transaction. Must be called with exclusive
- database write access already established (including the global
+ database write access already established (including the open
lock to prevent new processes attaching)
*/
int tdb_transaction_recover(struct tdb_context *tdb)
projects / ccan / blobdiff