** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
-
+
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
- allow for nested calls to tdb_transaction_start(), re-using the
existing transaction record. If the inner transaction is cancelled
then a subsequent commit will fail
-
+
- keep a mirrored copy of the tdb hash chain heads to allow for the
fast hash heads scan on traverse, updating the mirrored copy in
the transaction version of tdb_write
goto fail;
}
}
-
+
/* now copy it out of this block */
memcpy(buf, tdb->transaction->blocks[blk] + (off % tdb->transaction->block_size), len);
if (cv) {
}
}
}
-
+
/* overwrite part of an existing block */
if (buf == NULL) {
memset(tdb->transaction->blocks[blk] + off, 0, len);
return 0;
}
-/*
- brlock during a transaction - ignore them
-*/
-static int transaction_brlock(struct tdb_context *tdb,
- 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;
-}
-
-static int transaction_brunlock(struct tdb_context *tdb,
- int rw_type, tdb_off_t offset, size_t len)
-{
- return 0;
-}
-
static const struct tdb_methods transaction_methods = {
transaction_read,
transaction_write,
transaction_next_hash_chain,
transaction_oob,
transaction_expand_file,
- transaction_brlock,
- transaction_brunlock
};
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)
+static int _tdb_transaction_start(struct tdb_context *tdb,
+ enum tdb_lock_flags lockflags)
{
/* some sanity checks */
if (tdb->read_only || (tdb->flags & TDB_INTERNAL) || tdb->traverse_read) {
/* get the transaction write lock. This is a blocking lock. As
discussed with Volker, there are a number of ways we could
make this async, which we will probably do in the future */
- if (tdb_transaction_lock(tdb, F_WRLCK) == -1) {
+ if (tdb_transaction_lock(tdb, F_WRLCK, lockflags) == -1) {
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction);
+ if ((lockflags & TDB_LOCK_WAIT) == 0) {
+ tdb->ecode = TDB_ERR_NOLOCK;
+ }
return -1;
}
-
+
/* get a read lock from the freelist to the end of file. This
is upgraded to a write lock during the commit */
if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true) == -1) {
/* Trace at the end, so we get sequence number correct. */
tdb_trace(tdb, "tdb_transaction_start");
return 0;
-
+
fail:
tdb_allrecord_unlock(tdb, F_RDLCK, false);
fail_allrecord_lock:
return -1;
}
+int tdb_transaction_start(struct tdb_context *tdb)
+{
+ return _tdb_transaction_start(tdb, TDB_LOCK_WAIT);
+}
+
+int tdb_transaction_start_nonblock(struct tdb_context *tdb)
+{
+ return _tdb_transaction_start(tdb, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
+}
/*
sync to disk
}
-/* ltype is F_WRLCK after prepare. */
-static int _tdb_transaction_cancel(struct tdb_context *tdb, int ltype)
+static int _tdb_transaction_cancel(struct tdb_context *tdb)
{
int i, ret = 0;
}
/* This also removes the OPEN_LOCK, if we have it. */
- tdb_release_extra_locks(tdb);
+ tdb_release_transaction_locks(tdb);
/* restore the normal io methods */
tdb->methods = tdb->transaction->io_methods;
- tdb_transaction_unlock(tdb, F_WRLCK);
SAFE_FREE(tdb->transaction->hash_heads);
SAFE_FREE(tdb->transaction);
-
+
return ret;
}
*/
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);
}
/*
if (i == tdb->transaction->num_blocks-1) {
length = tdb->transaction->last_block_size;
}
-
+
if (offset >= old_map_size) {
continue;
}
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;
}
}
methods = tdb->transaction->io_methods;
-
+
/* if there are any locks pending then the caller has not
nested their locks properly, so fail the transaction */
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_allrecord_upgrade(tdb) == -1) {
TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_prepare_commit: failed to upgrade hash locks\n"));
- _tdb_transaction_cancel(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
during the commit */
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, F_WRLCK);
+ _tdb_transaction_cancel(tdb);
return -1;
}
/* 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;
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_commit: transaction error pending\n"));
return -1;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
- _tdb_transaction_cancel(tdb, F_RDLCK);
+ _tdb_transaction_cancel(tdb);
return 0;
}
if (methods->tdb_write(tdb, offset, tdb->transaction->blocks[i], length) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed during commit\n"));
-
+
/* we've overwritten part of the data and
possibly expanded the file, so we need to
run the crash recovery code */
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);
tdb->ecode = TDB_ERR_IO;
return -1;
}
-
- /* reduce the file size to the old size */
- tdb_munmap(tdb);
- if (ftruncate(tdb->fd, recovery_eof) != 0) {
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to reduce to recovery size\n"));
- tdb->ecode = TDB_ERR_IO;
- return -1;
- }
- tdb->map_size = recovery_eof;
- tdb_mmap(tdb);
if (transaction_sync(tdb, 0, recovery_eof) == -1) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync2 recovery\n"));
/* all done */
return 0;
}
+
+/* Any I/O failures we say "needs recovery". */
+bool tdb_needs_recovery(struct tdb_context *tdb)
+{
+ tdb_off_t recovery_head;
+ struct tdb_record rec;
+
+ /* find the recovery area */
+ if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) {
+ return true;
+ }
+
+ if (recovery_head == 0) {
+ /* we have never allocated a recovery record */
+ return false;
+ }
+
+ /* read the recovery record */
+ if (tdb->methods->tdb_read(tdb, recovery_head, &rec,
+ sizeof(rec), DOCONV()) == -1) {
+ return true;
+ }
+
+ return (rec.magic == TDB_RECOVERY_MAGIC);
+}
git.samba.org / sahlberg / ctdb.git / blobdiff