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@@ -0,0 +1,1191 @@
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+ /*
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+ Unix SMB/CIFS implementation.
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+
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+ trivial database library
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+
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+ Copyright (C) Andrew Tridgell 2005
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+ Copyright (C) Rusty Russell 2010
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+
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+ ** NOTE! The following LGPL license applies to the tdb
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+ ** library. This does NOT imply that all of Samba is released
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+ ** under the LGPL
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+
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+ This library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 3 of the License, or (at your option) any later version.
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+
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+ This library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
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+*/
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+
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+#include "private.h"
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+#define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
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+
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+/*
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+ transaction design:
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+
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+ - only allow a single transaction at a time per database. This makes
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+ using the transaction API simpler, as otherwise the caller would
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+ have to cope with temporary failures in transactions that conflict
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+ with other current transactions
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+
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+ - keep the transaction recovery information in the same file as the
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+ database, using a special 'transaction recovery' record pointed at
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+ by the header. This removes the need for extra journal files as
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+ used by some other databases
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+
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+ - dynamically allocated the transaction recover record, re-using it
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+ for subsequent transactions. If a larger record is needed then
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+ tdb_free() the old record to place it on the normal tdb freelist
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+ before allocating the new record
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+
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+ - during transactions, keep a linked list of writes all that have
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+ been performed by intercepting all tdb_write() calls. The hooked
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+ transaction versions of tdb_read() and tdb_write() check this
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+ linked list and try to use the elements of the list in preference
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+ to the real database.
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+
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+ - don't allow any locks to be held when a transaction starts,
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+ otherwise we can end up with deadlock (plus lack of lock nesting
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+ in posix locks would mean the lock is lost)
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+
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+ - if the caller gains a lock during the transaction but doesn't
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+ release it then fail the commit
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+
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+ - allow for nested calls to tdb_transaction_start(), re-using the
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+ existing transaction record. If the inner transaction is cancelled
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+ then a subsequent commit will fail
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+
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+ - keep a mirrored copy of the tdb hash chain heads to allow for the
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+ fast hash heads scan on traverse, updating the mirrored copy in
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+ the transaction version of tdb_write
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+
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+ - allow callers to mix transaction and non-transaction use of tdb,
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+ although once a transaction is started then an exclusive lock is
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+ gained until the transaction is committed or cancelled
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+
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+ - the commit stategy involves first saving away all modified data
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+ into a linearised buffer in the transaction recovery area, then
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+ marking the transaction recovery area with a magic value to
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+ indicate a valid recovery record. In total 4 fsync/msync calls are
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+ needed per commit to prevent race conditions. It might be possible
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+ to reduce this to 3 or even 2 with some more work.
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+
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+ - check for a valid recovery record on open of the tdb, while the
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+ open lock is held. Automatically recover from the transaction
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+ recovery area if needed, then continue with the open as
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+ usual. This allows for smooth crash recovery with no administrator
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+ intervention.
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+
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+ - if TDB_NOSYNC is passed to flags in tdb_open then transactions are
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+ still available, but no transaction recovery area is used and no
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+ fsync/msync calls are made.
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+*/
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+
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+
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+/*
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+ hold the context of any current transaction
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+*/
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+struct tdb_transaction {
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+ /* the original io methods - used to do IOs to the real db */
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+ const struct tdb_methods *io_methods;
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+
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+ /* the list of transaction blocks. When a block is first
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+ written to, it gets created in this list */
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+ uint8_t **blocks;
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+ size_t num_blocks;
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+ size_t last_block_size; /* number of valid bytes in the last block */
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+
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+ /* non-zero when an internal transaction error has
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+ occurred. All write operations will then fail until the
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+ transaction is ended */
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+ int transaction_error;
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+
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+ /* when inside a transaction we need to keep track of any
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+ nested tdb_transaction_start() calls, as these are allowed,
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+ but don't create a new transaction */
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+ int nesting;
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+
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+ /* set when a prepare has already occurred */
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+ bool prepared;
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+ tdb_off_t magic_offset;
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+
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+ /* old file size before transaction */
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+ tdb_len_t old_map_size;
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+};
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+
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+
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+/*
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+ read while in a transaction. We need to check first if the data is in our list
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+ of transaction elements, then if not do a real read
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+*/
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+static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf,
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+ tdb_len_t len)
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+{
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+ size_t blk;
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+
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+ /* break it down into block sized ops */
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+ while (len + (off % getpagesize()) > getpagesize()) {
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+ tdb_len_t len2 = getpagesize() - (off % getpagesize());
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+ if (transaction_read(tdb, off, buf, len2) != 0) {
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+ return -1;
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+ }
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+ len -= len2;
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+ off += len2;
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+ buf = (void *)(len2 + (char *)buf);
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+ }
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+
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+ if (len == 0) {
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+ return 0;
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+ }
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+
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+ blk = off / getpagesize();
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+
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+ /* see if we have it in the block list */
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+ if (tdb->transaction->num_blocks <= blk ||
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+ tdb->transaction->blocks[blk] == NULL) {
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+ /* nope, do a real read */
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+ if (tdb->transaction->io_methods->read(tdb, off, buf, len) != 0) {
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+ goto fail;
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+ }
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+ return 0;
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+ }
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+
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+ /* it is in the block list. Now check for the last block */
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+ if (blk == tdb->transaction->num_blocks-1) {
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+ if (len > tdb->transaction->last_block_size) {
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+ goto fail;
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+ }
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+ }
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+
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+ /* now copy it out of this block */
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+ memcpy(buf, tdb->transaction->blocks[blk] + (off % getpagesize()), len);
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+ return 0;
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+
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+fail:
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+ tdb->ecode = TDB_ERR_IO;
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+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
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+ "transaction_read: failed at off=%llu len=%llu\n",
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+ (long long)off, (long long)len);
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+ tdb->transaction->transaction_error = 1;
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+ return -1;
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+}
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+
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+
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+/*
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+ write while in a transaction
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+*/
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+static int transaction_write(struct tdb_context *tdb, tdb_off_t off,
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+ const void *buf, tdb_len_t len)
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+{
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+ size_t blk;
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+
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+ /* Only a commit is allowed on a prepared transaction */
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+ if (tdb->transaction->prepared) {
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+ tdb->ecode = TDB_ERR_EINVAL;
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+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
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+ "transaction_write: transaction already prepared,"
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+ " write not allowed\n");
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+ tdb->transaction->transaction_error = 1;
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+ return -1;
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+ }
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+
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+ /* break it up into block sized chunks */
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+ while (len + (off % getpagesize()) > getpagesize()) {
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+ tdb_len_t len2 = getpagesize() - (off % getpagesize());
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+ if (transaction_write(tdb, off, buf, len2) != 0) {
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+ return -1;
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+ }
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+ len -= len2;
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+ off += len2;
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+ if (buf != NULL) {
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+ buf = (const void *)(len2 + (const char *)buf);
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+ }
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+ }
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+
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+ if (len == 0) {
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+ return 0;
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+ }
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+
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+ blk = off / getpagesize();
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+ off = off % getpagesize();
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+
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+ if (tdb->transaction->num_blocks <= blk) {
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+ uint8_t **new_blocks;
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+ /* expand the blocks array */
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+ if (tdb->transaction->blocks == NULL) {
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+ new_blocks = (uint8_t **)malloc(
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+ (blk+1)*sizeof(uint8_t *));
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+ } else {
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+ new_blocks = (uint8_t **)realloc(
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+ tdb->transaction->blocks,
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+ (blk+1)*sizeof(uint8_t *));
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+ }
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+ if (new_blocks == NULL) {
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+ tdb->ecode = TDB_ERR_OOM;
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+ goto fail;
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+ }
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+ memset(&new_blocks[tdb->transaction->num_blocks], 0,
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+ (1+(blk - tdb->transaction->num_blocks))*sizeof(uint8_t *));
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+ tdb->transaction->blocks = new_blocks;
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+ tdb->transaction->num_blocks = blk+1;
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+ tdb->transaction->last_block_size = 0;
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+ }
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+
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+ /* allocate and fill a block? */
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+ if (tdb->transaction->blocks[blk] == NULL) {
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+ tdb->transaction->blocks[blk] = (uint8_t *)calloc(getpagesize(), 1);
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+ if (tdb->transaction->blocks[blk] == NULL) {
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+ tdb->ecode = TDB_ERR_OOM;
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+ tdb->transaction->transaction_error = 1;
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+ return -1;
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+ }
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+ if (tdb->transaction->old_map_size > blk * getpagesize()) {
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+ tdb_len_t len2 = getpagesize();
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+ if (len2 + (blk * getpagesize()) > tdb->transaction->old_map_size) {
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+ len2 = tdb->transaction->old_map_size - (blk * getpagesize());
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+ }
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+ if (tdb->transaction->io_methods->read(tdb, blk * getpagesize(),
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+ tdb->transaction->blocks[blk],
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+ len2) != 0) {
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+ SAFE_FREE(tdb->transaction->blocks[blk]);
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+ goto fail;
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+ }
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+ if (blk == tdb->transaction->num_blocks-1) {
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+ tdb->transaction->last_block_size = len2;
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+ }
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+ }
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+ }
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+
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+ /* overwrite part of an existing block */
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+ if (buf == NULL) {
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+ memset(tdb->transaction->blocks[blk] + off, 0, len);
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+ } else {
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+ memcpy(tdb->transaction->blocks[blk] + off, buf, len);
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+ }
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+ if (blk == tdb->transaction->num_blocks-1) {
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+ if (len + off > tdb->transaction->last_block_size) {
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+ tdb->transaction->last_block_size = len + off;
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+ }
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+ }
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+
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+ return 0;
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+
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+fail:
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+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
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+ "transaction_write: failed at off=%llu len=%llu\n",
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+ (long long)((blk*getpagesize()) + off),
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+ (long long)len);
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+ tdb->transaction->transaction_error = 1;
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+ return -1;
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+}
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+
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+
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+/*
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+ write while in a transaction - this varient never expands the transaction blocks, it only
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+ updates existing blocks. This means it cannot change the recovery size
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+*/
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+static void transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
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+ const void *buf, tdb_len_t len)
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+{
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+ size_t blk;
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+
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+ /* break it up into block sized chunks */
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+ while (len + (off % getpagesize()) > getpagesize()) {
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+ tdb_len_t len2 = getpagesize() - (off % getpagesize());
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+ transaction_write_existing(tdb, off, buf, len2);
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+ len -= len2;
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+ off += len2;
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+ if (buf != NULL) {
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+ buf = (const void *)(len2 + (const char *)buf);
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+ }
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+ }
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+
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+ if (len == 0) {
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+ return;
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+ }
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+
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+ blk = off / getpagesize();
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+ off = off % getpagesize();
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+
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+ if (tdb->transaction->num_blocks <= blk ||
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+ tdb->transaction->blocks[blk] == NULL) {
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+ return;
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+ }
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+
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+ if (blk == tdb->transaction->num_blocks-1 &&
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+ off + len > tdb->transaction->last_block_size) {
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+ if (off >= tdb->transaction->last_block_size) {
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+ return;
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+ }
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+ len = tdb->transaction->last_block_size - off;
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+ }
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+
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+ /* overwrite part of an existing block */
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+ memcpy(tdb->transaction->blocks[blk] + off, buf, len);
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+}
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+
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+
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+/*
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+ out of bounds check during a transaction
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+*/
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+static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, bool probe)
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+{
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+ if (len <= tdb->map_size) {
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+ return 0;
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+ }
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+ tdb->ecode = TDB_ERR_IO;
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+ return -1;
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+}
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+
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+/*
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+ transaction version of tdb_expand().
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+*/
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+static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t addition)
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+{
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+ /* add a write to the transaction elements, so subsequent
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+ reads see the zero data */
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+ if (transaction_write(tdb, tdb->map_size, NULL, addition) != 0) {
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+ return -1;
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+ }
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+ tdb->map_size += addition;
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+ return 0;
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+}
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+
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+static void *transaction_direct(struct tdb_context *tdb, tdb_off_t off,
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+ size_t len)
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+{
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+ /* FIXME */
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+ return NULL;
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+}
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+
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+static const struct tdb_methods transaction_methods = {
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+ transaction_read,
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+ transaction_write,
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+ transaction_oob,
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+ transaction_expand_file,
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+ transaction_direct,
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+};
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+
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+/*
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+ sync to disk
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+*/
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+static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length)
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+{
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+ if (tdb->flags & TDB_NOSYNC) {
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+ return 0;
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+ }
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+
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+ if (fsync(tdb->fd) != 0) {
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+ tdb->ecode = TDB_ERR_IO;
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+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
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+ "tdb_transaction: fsync failed\n");
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+ return -1;
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+ }
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+#ifdef MS_SYNC
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+ if (tdb->map_ptr) {
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+ tdb_off_t moffset = offset & ~(getpagesize()-1);
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+ if (msync(moffset + (char *)tdb->map_ptr,
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+ length + (offset - moffset), MS_SYNC) != 0) {
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+ tdb->ecode = TDB_ERR_IO;
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+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
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+ "tdb_transaction: msync failed - %s\n",
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+ strerror(errno));
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+ return -1;
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+ }
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+ }
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+#endif
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+ return 0;
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+}
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+
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+
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+static void _tdb_transaction_cancel(struct tdb_context *tdb)
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+{
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+ int i;
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+
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+ if (tdb->transaction == NULL) {
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|
|
+ tdb->ecode = TDB_ERR_EINVAL;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_cancel: no transaction\n");
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb->transaction->nesting != 0) {
|
|
|
+ tdb->transaction->transaction_error = 1;
|
|
|
+ tdb->transaction->nesting--;
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ tdb->map_size = tdb->transaction->old_map_size;
|
|
|
+
|
|
|
+ /* free all the transaction blocks */
|
|
|
+ for (i=0;i<tdb->transaction->num_blocks;i++) {
|
|
|
+ if (tdb->transaction->blocks[i] != NULL) {
|
|
|
+ free(tdb->transaction->blocks[i]);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ SAFE_FREE(tdb->transaction->blocks);
|
|
|
+
|
|
|
+ if (tdb->transaction->magic_offset) {
|
|
|
+ const struct tdb_methods *methods = tdb->transaction->io_methods;
|
|
|
+ uint64_t invalid = TDB_RECOVERY_INVALID_MAGIC;
|
|
|
+
|
|
|
+ /* remove the recovery marker */
|
|
|
+ if (methods->write(tdb, tdb->transaction->magic_offset,
|
|
|
+ &invalid, sizeof(invalid)) == -1 ||
|
|
|
+ transaction_sync(tdb, tdb->transaction->magic_offset,
|
|
|
+ sizeof(invalid)) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_cancel: failed to remove"
|
|
|
+ " recovery magic\n");
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb->allrecord_lock.count)
|
|
|
+ tdb_allrecord_unlock(tdb, tdb->allrecord_lock.ltype);
|
|
|
+
|
|
|
+ /* restore the normal io methods */
|
|
|
+ tdb->methods = tdb->transaction->io_methods;
|
|
|
+
|
|
|
+ tdb_transaction_unlock(tdb, F_WRLCK);
|
|
|
+ tdb_unlock_expand(tdb, F_WRLCK);
|
|
|
+
|
|
|
+ if (tdb_has_open_lock(tdb))
|
|
|
+ tdb_unlock_open(tdb);
|
|
|
+
|
|
|
+ SAFE_FREE(tdb->transaction);
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ 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)
|
|
|
+{
|
|
|
+ /* some sanity checks */
|
|
|
+ if (tdb->read_only || (tdb->flags & TDB_INTERNAL)) {
|
|
|
+ tdb->ecode = TDB_ERR_EINVAL;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_start: cannot start a transaction"
|
|
|
+ " on a read-only or internal db\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* cope with nested tdb_transaction_start() calls */
|
|
|
+ if (tdb->transaction != NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_NESTING;
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb_has_hash_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 */
|
|
|
+ tdb->ecode = TDB_ERR_LOCK;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_start: cannot start a transaction"
|
|
|
+ " with locks held\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ tdb->transaction = (struct tdb_transaction *)
|
|
|
+ calloc(sizeof(struct tdb_transaction), 1);
|
|
|
+ if (tdb->transaction == NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_OOM;
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* 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) {
|
|
|
+ SAFE_FREE(tdb->transaction->blocks);
|
|
|
+ SAFE_FREE(tdb->transaction);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* get a read lock over entire file. This is upgraded to a write
|
|
|
+ lock during the commit */
|
|
|
+ if (tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, true) == -1) {
|
|
|
+ goto fail_allrecord_lock;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb_lock_expand(tdb, F_WRLCK) != 0) {
|
|
|
+ goto fail_expand_lock;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* make sure we know about any file expansions already done by
|
|
|
+ anyone else */
|
|
|
+ tdb->methods->oob(tdb, tdb->map_size + 1, true);
|
|
|
+ tdb->transaction->old_map_size = tdb->map_size;
|
|
|
+
|
|
|
+ /* finally hook the io methods, replacing them with
|
|
|
+ transaction specific methods */
|
|
|
+ tdb->transaction->io_methods = tdb->methods;
|
|
|
+ tdb->methods = &transaction_methods;
|
|
|
+ return 0;
|
|
|
+
|
|
|
+fail_expand_lock:
|
|
|
+ tdb_allrecord_unlock(tdb, F_RDLCK);
|
|
|
+fail_allrecord_lock:
|
|
|
+ tdb_transaction_unlock(tdb, F_WRLCK);
|
|
|
+ SAFE_FREE(tdb->transaction->blocks);
|
|
|
+ SAFE_FREE(tdb->transaction);
|
|
|
+ return -1;
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+/*
|
|
|
+ cancel the current transaction
|
|
|
+*/
|
|
|
+void tdb_transaction_cancel(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ work out how much space the linearised recovery data will consume
|
|
|
+*/
|
|
|
+static tdb_len_t tdb_recovery_size(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ tdb_len_t recovery_size = 0;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ recovery_size = sizeof(tdb_len_t);
|
|
|
+ for (i=0;i<tdb->transaction->num_blocks;i++) {
|
|
|
+ if (i * getpagesize() >= tdb->transaction->old_map_size) {
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ if (tdb->transaction->blocks[i] == NULL) {
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+ recovery_size += 2*sizeof(tdb_off_t);
|
|
|
+ if (i == tdb->transaction->num_blocks-1) {
|
|
|
+ recovery_size += tdb->transaction->last_block_size;
|
|
|
+ } else {
|
|
|
+ recovery_size += getpagesize();
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return recovery_size;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ allocate the recovery area, or use an existing recovery area if it is
|
|
|
+ large enough
|
|
|
+*/
|
|
|
+static int tdb_recovery_allocate(struct tdb_context *tdb,
|
|
|
+ tdb_len_t *recovery_size,
|
|
|
+ tdb_off_t *recovery_offset,
|
|
|
+ tdb_len_t *recovery_max_size)
|
|
|
+{
|
|
|
+ struct tdb_recovery_record rec;
|
|
|
+ const struct tdb_methods *methods = tdb->transaction->io_methods;
|
|
|
+ tdb_off_t recovery_head;
|
|
|
+ size_t addition;
|
|
|
+
|
|
|
+ recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
|
|
|
+ if (recovery_head == TDB_OFF_ERR) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_recovery_allocate:"
|
|
|
+ " failed to read recovery head\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (recovery_head != 0) {
|
|
|
+ if (methods->read(tdb, recovery_head, &rec, sizeof(rec))) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_recovery_allocate:"
|
|
|
+ " failed to read recovery record\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ tdb_convert(tdb, &rec, sizeof(rec));
|
|
|
+ /* ignore invalid recovery regions: can happen in crash */
|
|
|
+ if (rec.magic != TDB_RECOVERY_MAGIC &&
|
|
|
+ rec.magic != TDB_RECOVERY_INVALID_MAGIC) {
|
|
|
+ recovery_head = 0;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ *recovery_size = tdb_recovery_size(tdb);
|
|
|
+
|
|
|
+ if (recovery_head != 0 && *recovery_size <= rec.max_len) {
|
|
|
+ /* it fits in the existing area */
|
|
|
+ *recovery_max_size = rec.max_len;
|
|
|
+ *recovery_offset = recovery_head;
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* we need to free up the old recovery area, then allocate a
|
|
|
+ new one at the end of the file. Note that we cannot use
|
|
|
+ normal allocation to allocate the new one as that might return
|
|
|
+ us an area that is being currently used (as of the start of
|
|
|
+ the transaction) */
|
|
|
+ if (recovery_head != 0) {
|
|
|
+ if (add_free_record(tdb, recovery_head,
|
|
|
+ sizeof(rec) + rec.max_len) != 0) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_recovery_allocate:"
|
|
|
+ " failed to free previous recovery area\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ /* the tdb_free() call might have increased the recovery size */
|
|
|
+ *recovery_size = tdb_recovery_size(tdb);
|
|
|
+
|
|
|
+ /* round up to a multiple of page size */
|
|
|
+ *recovery_max_size
|
|
|
+ = (((sizeof(rec) + *recovery_size) + getpagesize()-1)
|
|
|
+ & ~(getpagesize()-1))
|
|
|
+ - sizeof(rec);
|
|
|
+ *recovery_offset = tdb->map_size;
|
|
|
+ recovery_head = *recovery_offset;
|
|
|
+
|
|
|
+ /* Restore ->map_size before calling underlying expand_file.
|
|
|
+ Also so that we don't try to expand the file again in the
|
|
|
+ transaction commit, which would destroy the recovery
|
|
|
+ area */
|
|
|
+ addition = (tdb->map_size - tdb->transaction->old_map_size) +
|
|
|
+ sizeof(rec) + *recovery_max_size;
|
|
|
+ tdb->map_size = tdb->transaction->old_map_size;
|
|
|
+ if (methods->expand_file(tdb, addition) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_recovery_allocate:"
|
|
|
+ " failed to create recovery area\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* we have to reset the old map size so that we don't try to
|
|
|
+ expand the file again in the transaction commit, which
|
|
|
+ would destroy the recovery area */
|
|
|
+ tdb->transaction->old_map_size = tdb->map_size;
|
|
|
+
|
|
|
+ /* write the recovery header offset and sync - we can sync without a race here
|
|
|
+ as the magic ptr in the recovery record has not been set */
|
|
|
+ tdb_convert(tdb, &recovery_head, sizeof(recovery_head));
|
|
|
+ if (methods->write(tdb, offsetof(struct tdb_header, recovery),
|
|
|
+ &recovery_head, sizeof(tdb_off_t)) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_recovery_allocate:"
|
|
|
+ " failed to write recovery head\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ transaction_write_existing(tdb, offsetof(struct tdb_header, recovery),
|
|
|
+ &recovery_head,
|
|
|
+ sizeof(tdb_off_t));
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+/* Set up header for the recovery record. */
|
|
|
+static void set_recovery_header(struct tdb_recovery_record *rec,
|
|
|
+ uint64_t magic,
|
|
|
+ uint64_t datalen, uint64_t actuallen,
|
|
|
+ uint64_t oldsize)
|
|
|
+{
|
|
|
+ rec->magic = magic;
|
|
|
+ rec->max_len = actuallen;
|
|
|
+ rec->len = datalen;
|
|
|
+ rec->eof = oldsize;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ setup the recovery data that will be used on a crash during commit
|
|
|
+*/
|
|
|
+static int transaction_setup_recovery(struct tdb_context *tdb,
|
|
|
+ tdb_off_t *magic_offset)
|
|
|
+{
|
|
|
+ tdb_len_t recovery_size;
|
|
|
+ unsigned char *data, *p;
|
|
|
+ const struct tdb_methods *methods = tdb->transaction->io_methods;
|
|
|
+ struct tdb_recovery_record *rec;
|
|
|
+ tdb_off_t recovery_offset, recovery_max_size;
|
|
|
+ tdb_off_t old_map_size = tdb->transaction->old_map_size;
|
|
|
+ uint64_t magic, tailer;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ /*
|
|
|
+ check that the recovery area has enough space
|
|
|
+ */
|
|
|
+ if (tdb_recovery_allocate(tdb, &recovery_size,
|
|
|
+ &recovery_offset, &recovery_max_size) == -1) {
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ data = (unsigned char *)malloc(recovery_size + sizeof(*rec));
|
|
|
+ if (data == NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_OOM;
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ rec = (struct tdb_recovery_record *)data;
|
|
|
+ set_recovery_header(rec, TDB_RECOVERY_INVALID_MAGIC,
|
|
|
+ recovery_size, recovery_max_size, old_map_size);
|
|
|
+ tdb_convert(tdb, rec, sizeof(*rec));
|
|
|
+
|
|
|
+ /* build the recovery data into a single blob to allow us to do a single
|
|
|
+ large write, which should be more efficient */
|
|
|
+ p = data + sizeof(*rec);
|
|
|
+ for (i=0;i<tdb->transaction->num_blocks;i++) {
|
|
|
+ tdb_off_t offset;
|
|
|
+ tdb_len_t length;
|
|
|
+
|
|
|
+ if (tdb->transaction->blocks[i] == NULL) {
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+
|
|
|
+ offset = i * getpagesize();
|
|
|
+ length = getpagesize();
|
|
|
+ if (i == tdb->transaction->num_blocks-1) {
|
|
|
+ length = tdb->transaction->last_block_size;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (offset >= old_map_size) {
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+ if (offset + length > tdb->map_size) {
|
|
|
+ tdb->ecode = TDB_ERR_CORRUPT;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_setup_recovery:"
|
|
|
+ " transaction data over new region boundary\n");
|
|
|
+ free(data);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ memcpy(p, &offset, sizeof(offset));
|
|
|
+ memcpy(p + sizeof(offset), &length, sizeof(length));
|
|
|
+ tdb_convert(tdb, p, sizeof(offset) + sizeof(length));
|
|
|
+
|
|
|
+ /* the recovery area contains the old data, not the
|
|
|
+ new data, so we have to call the original tdb_read
|
|
|
+ method to get it */
|
|
|
+ if (methods->read(tdb, offset,
|
|
|
+ p + sizeof(offset) + sizeof(length),
|
|
|
+ length) != 0) {
|
|
|
+ free(data);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ p += sizeof(offset) + sizeof(length) + length;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* and the tailer */
|
|
|
+ tailer = sizeof(*rec) + recovery_max_size;
|
|
|
+ memcpy(p, &tailer, sizeof(tailer));
|
|
|
+ tdb_convert(tdb, p, sizeof(tailer));
|
|
|
+
|
|
|
+ /* write the recovery data to the recovery area */
|
|
|
+ if (methods->write(tdb, recovery_offset, data,
|
|
|
+ sizeof(*rec) + recovery_size) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_setup_recovery:"
|
|
|
+ " failed to write recovery data\n");
|
|
|
+ free(data);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ transaction_write_existing(tdb, recovery_offset, data,
|
|
|
+ sizeof(*rec) + recovery_size);
|
|
|
+
|
|
|
+ /* as we don't have ordered writes, we have to sync the recovery
|
|
|
+ data before we update the magic to indicate that the recovery
|
|
|
+ data is present */
|
|
|
+ if (transaction_sync(tdb, recovery_offset,
|
|
|
+ sizeof(*rec) + recovery_size) == -1) {
|
|
|
+ free(data);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ free(data);
|
|
|
+
|
|
|
+ magic = TDB_RECOVERY_MAGIC;
|
|
|
+ tdb_convert(tdb, &magic, sizeof(magic));
|
|
|
+
|
|
|
+ *magic_offset = recovery_offset + offsetof(struct tdb_recovery_record,
|
|
|
+ magic);
|
|
|
+
|
|
|
+ if (methods->write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_setup_recovery:"
|
|
|
+ " failed to write recovery magic\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic));
|
|
|
+
|
|
|
+ /* ensure the recovery magic marker is on disk */
|
|
|
+ if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) {
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static int _tdb_transaction_prepare_commit(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ const struct tdb_methods *methods;
|
|
|
+
|
|
|
+ if (tdb->transaction == NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_EINVAL;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit: no transaction\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb->transaction->prepared) {
|
|
|
+ tdb->ecode = TDB_ERR_EINVAL;
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " transaction already prepared\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb->transaction->transaction_error) {
|
|
|
+ tdb->ecode = TDB_ERR_IO;
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " transaction error pending\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+
|
|
|
+ if (tdb->transaction->nesting != 0) {
|
|
|
+ tdb->transaction->nesting--;
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* check for a null transaction */
|
|
|
+ if (tdb->transaction->blocks == NULL) {
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ methods = tdb->transaction->io_methods;
|
|
|
+
|
|
|
+ /* upgrade the main transaction lock region to a write lock */
|
|
|
+ if (tdb_allrecord_upgrade(tdb) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " failed to upgrade hash locks\n");
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* get the open lock - this prevents new users attaching to the database
|
|
|
+ during the commit */
|
|
|
+ if (tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " failed to get open lock\n");
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ 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_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " failed to setup recovery data\n");
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ tdb->transaction->prepared = true;
|
|
|
+
|
|
|
+ /* expand the file to the new size if needed */
|
|
|
+ if (tdb->map_size != tdb->transaction->old_map_size) {
|
|
|
+ tdb_len_t add = tdb->map_size - tdb->transaction->old_map_size;
|
|
|
+ /* Restore original map size for tdb_expand_file */
|
|
|
+ tdb->map_size = tdb->transaction->old_map_size;
|
|
|
+ if (methods->expand_file(tdb, add) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_prepare_commit:"
|
|
|
+ " expansion failed\n");
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Keep the open lock until the actual commit */
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ prepare to commit the current transaction
|
|
|
+*/
|
|
|
+int tdb_transaction_prepare_commit(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ return _tdb_transaction_prepare_commit(tdb);
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ commit the current transaction
|
|
|
+*/
|
|
|
+int tdb_transaction_commit(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ const struct tdb_methods *methods;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ if (tdb->transaction == NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_EINVAL;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_commit: no transaction\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ tdb_trace(tdb, "tdb_transaction_commit");
|
|
|
+
|
|
|
+ if (tdb->transaction->transaction_error) {
|
|
|
+ tdb->ecode = TDB_ERR_IO;
|
|
|
+ tdb_transaction_cancel(tdb);
|
|
|
+ tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
|
|
|
+ "tdb_transaction_commit: transaction error pending\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+
|
|
|
+ if (tdb->transaction->nesting != 0) {
|
|
|
+ tdb->transaction->nesting--;
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* check for a null transaction */
|
|
|
+ if (tdb->transaction->blocks == NULL) {
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!tdb->transaction->prepared) {
|
|
|
+ int ret = _tdb_transaction_prepare_commit(tdb);
|
|
|
+ if (ret)
|
|
|
+ return ret;
|
|
|
+ }
|
|
|
+
|
|
|
+ methods = tdb->transaction->io_methods;
|
|
|
+
|
|
|
+ /* perform all the writes */
|
|
|
+ for (i=0;i<tdb->transaction->num_blocks;i++) {
|
|
|
+ tdb_off_t offset;
|
|
|
+ tdb_len_t length;
|
|
|
+
|
|
|
+ if (tdb->transaction->blocks[i] == NULL) {
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+
|
|
|
+ offset = i * getpagesize();
|
|
|
+ length = getpagesize();
|
|
|
+ if (i == tdb->transaction->num_blocks-1) {
|
|
|
+ length = tdb->transaction->last_block_size;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (methods->write(tdb, offset, tdb->transaction->blocks[i],
|
|
|
+ length) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "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);
|
|
|
+
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ SAFE_FREE(tdb->transaction->blocks[i]);
|
|
|
+ }
|
|
|
+
|
|
|
+ SAFE_FREE(tdb->transaction->blocks);
|
|
|
+ tdb->transaction->num_blocks = 0;
|
|
|
+
|
|
|
+ /* ensure the new data is on disk */
|
|
|
+ if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /*
|
|
|
+ TODO: maybe write to some dummy hdr field, or write to magic
|
|
|
+ offset without mmap, before the last sync, instead of the
|
|
|
+ utime() call
|
|
|
+ */
|
|
|
+
|
|
|
+ /* on some systems (like Linux 2.6.x) changes via mmap/msync
|
|
|
+ don't change the mtime of the file, this means the file may
|
|
|
+ not be backed up (as tdb rounding to block sizes means that
|
|
|
+ file size changes are quite rare too). The following forces
|
|
|
+ mtime changes when a transaction completes */
|
|
|
+#if HAVE_UTIME
|
|
|
+ utime(tdb->name, NULL);
|
|
|
+#endif
|
|
|
+
|
|
|
+ /* use a transaction cancel to free memory and remove the
|
|
|
+ transaction locks */
|
|
|
+ _tdb_transaction_cancel(tdb);
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+/*
|
|
|
+ recover from an aborted transaction. Must be called with exclusive
|
|
|
+ database write access already established (including the open
|
|
|
+ lock to prevent new processes attaching)
|
|
|
+*/
|
|
|
+int tdb_transaction_recover(struct tdb_context *tdb)
|
|
|
+{
|
|
|
+ tdb_off_t recovery_head, recovery_eof;
|
|
|
+ unsigned char *data, *p;
|
|
|
+ struct tdb_recovery_record rec;
|
|
|
+
|
|
|
+ /* find the recovery area */
|
|
|
+ recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
|
|
|
+ if (recovery_head == TDB_OFF_ERR) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to read recovery head\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (recovery_head == 0) {
|
|
|
+ /* we have never allocated a recovery record */
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* read the recovery record */
|
|
|
+ if (tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec)) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to read recovery record\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (rec.magic != TDB_RECOVERY_MAGIC) {
|
|
|
+ /* there is no valid recovery data */
|
|
|
+ return 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tdb->read_only) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " attempt to recover read only database\n");
|
|
|
+ tdb->ecode = TDB_ERR_CORRUPT;
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ recovery_eof = rec.eof;
|
|
|
+
|
|
|
+ data = (unsigned char *)malloc(rec.len);
|
|
|
+ if (data == NULL) {
|
|
|
+ tdb->ecode = TDB_ERR_OOM;
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to allocate recovery data\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* read the full recovery data */
|
|
|
+ if (tdb->methods->read(tdb, recovery_head + sizeof(rec), data,
|
|
|
+ rec.len) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to read recovery data\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* recover the file data */
|
|
|
+ p = data;
|
|
|
+ while (p+sizeof(tdb_off_t)+sizeof(tdb_len_t) < data + rec.len) {
|
|
|
+ tdb_off_t ofs;
|
|
|
+ tdb_len_t len;
|
|
|
+ tdb_convert(tdb, p, sizeof(ofs) + sizeof(len));
|
|
|
+ memcpy(&ofs, p, sizeof(ofs));
|
|
|
+ memcpy(&len, p + sizeof(ofs), sizeof(len));
|
|
|
+ p += sizeof(ofs) + sizeof(len);
|
|
|
+
|
|
|
+ if (tdb->methods->write(tdb, ofs, p, len) == -1) {
|
|
|
+ free(data);
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to recover %zu bytes at offset %zu\n",
|
|
|
+ (size_t)len, (size_t)ofs);
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ p += len;
|
|
|
+ }
|
|
|
+
|
|
|
+ free(data);
|
|
|
+
|
|
|
+ if (transaction_sync(tdb, 0, tdb->map_size) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover: failed to sync recovery\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* if the recovery area is after the recovered eof then remove it */
|
|
|
+ if (recovery_eof <= recovery_head) {
|
|
|
+ if (tdb_write_off(tdb, offsetof(struct tdb_header,recovery), 0)
|
|
|
+ == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to remove recovery head\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ /* remove the recovery magic */
|
|
|
+ if (tdb_write_off(tdb,
|
|
|
+ recovery_head
|
|
|
+ + offsetof(struct tdb_recovery_record, magic),
|
|
|
+ TDB_RECOVERY_INVALID_MAGIC) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover:"
|
|
|
+ " failed to remove recovery magic\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (transaction_sync(tdb, 0, recovery_eof) == -1) {
|
|
|
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover: failed to sync2 recovery\n");
|
|
|
+ return -1;
|
|
|
+ }
|
|
|
+
|
|
|
+ tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
|
|
|
+ "tdb_transaction_recover: recovered %zu byte database\n",
|
|
|
+ (size_t)recovery_eof);
|
|
|
+
|
|
|
+ /* 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_recovery_record rec;
|
|
|
+
|
|
|
+ /* find the recovery area */
|
|
|
+ recovery_head = tdb_read_off(tdb, offsetof(struct tdb_header,recovery));
|
|
|
+ if (recovery_head == TDB_OFF_ERR) {
|
|
|
+ return true;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (recovery_head == 0) {
|
|
|
+ /* we have never allocated a recovery record */
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* read the recovery record */
|
|
|
+ if (tdb_read_convert(tdb, recovery_head, &rec, sizeof(rec)) == -1) {
|
|
|
+ return true;
|
|
|
+ }
|
|
|
+
|
|
|
+ return (rec.magic == TDB_RECOVERY_MAGIC);
|
|
|
+}
|
Rusty Russell