3 files changed, 86 insertions, 0 deletions

diff --git a/lib/tdb/common/lock.c b/lib/tdb/common/lock.c
index adff8a6580..65d68432fe 100644
--- a/lib/tdb/common/lock.c
+++ b/lib/tdb/common/lock.c
@@ -309,10 +309,44 @@ int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
 	return 0;
 }
 
+static int tdb_lock_and_recover(struct tdb_context *tdb)
+{
+	int ret;
+
+	/* We need to match locking order in transaction commit. */
+	if (tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0, TDB_LOCK_WAIT)) {
+		return -1;
+	}
+
+	if (tdb_brlock(tdb, F_WRLCK, OPEN_LOCK, 1, TDB_LOCK_WAIT)) {
+		tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
+		return -1;
+	}
+
+	ret = tdb_transaction_recover(tdb);
+
+	tdb_brunlock(tdb, F_WRLCK, OPEN_LOCK, 1);
+	tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
+
+	return ret;
+}
+
+static bool have_data_locks(const struct tdb_context *tdb)
+{
+	unsigned int i;
+
+	for (i = 0; i < tdb->num_lockrecs; i++) {
+		if (tdb->lockrecs[i].off >= lock_offset(-1))
+			return true;
+	}
+	return false;
+}
+
 static int tdb_lock_list(struct tdb_context *tdb, int list, int ltype,
 			 enum tdb_lock_flags waitflag)
 {
 	int ret;
+	bool check = false;
 
 	/* a allrecord lock allows us to avoid per chain locks */
 	if (tdb->allrecord_lock.count &&
@@ -324,7 +358,18 @@ static int tdb_lock_list(struct tdb_context *tdb, int list, int ltype,
 		tdb->ecode = TDB_ERR_LOCK;
 		ret = -1;
 	} else {
+		/* Only check when we grab first data lock. */
+		check = !have_data_locks(tdb);
 		ret = tdb_nest_lock(tdb, lock_offset(list), ltype, waitflag);
+
+		if (ret == 0 && check && tdb_needs_recovery(tdb)) {
+			tdb_nest_unlock(tdb, lock_offset(list), ltype, false);
+
+			if (tdb_lock_and_recover(tdb) == -1) {
+				return -1;
+			}
+			return tdb_lock_list(tdb, list, ltype, waitflag);
+		}
 	}
 	return ret;
 }
@@ -488,6 +533,21 @@ int tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
 	tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
 	tdb->allrecord_lock.off = upgradable;
 
+	if (tdb_needs_recovery(tdb)) {
+		bool mark = flags & TDB_LOCK_MARK_ONLY;
+		tdb_allrecord_unlock(tdb, ltype, mark);
+		if (mark) {
+			tdb->ecode = TDB_ERR_LOCK;
+			TDB_LOG((tdb, TDB_DEBUG_ERROR,
+				 "tdb_lockall_mark cannot do recovery\n"));
+			return -1;
+		}
+		if (tdb_lock_and_recover(tdb) == -1) {
+			return -1;
+		}
+		return tdb_allrecord_lock(tdb, ltype, flags, upgradable);
+	}
+
 	return 0;
 }
 
diff --git a/lib/tdb/common/tdb_private.h b/lib/tdb/common/tdb_private.h
index f086e7d905..a0e3f20b4e 100644
--- a/lib/tdb/common/tdb_private.h
+++ b/lib/tdb/common/tdb_private.h
@@ -249,6 +249,7 @@ int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off);
 int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off);
+bool tdb_needs_recovery(struct tdb_context *tdb);
 int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec);
 int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec);
 int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct tdb_record *rec);
diff --git a/lib/tdb/common/transaction.c b/lib/tdb/common/transaction.c
index 3d267af2b0..4f1cc708ef 100644
--- a/lib/tdb/common/transaction.c
+++ b/lib/tdb/common/transaction.c
@@ -1192,3 +1192,28 @@ int tdb_transaction_recover(struct tdb_context *tdb)
 	/* 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);
+}