tdb_chainlock() in tdb1, tdb2 and tdb_compat ?

[Volker Lendecke]

Hi!

Can someone on this list enlighten me? I am confused about
the role of tdb_compat. In the combined build, what happens
in legacy source3 code if I call tdb_chainlock? When using
the autoconf based build, I think I should get tdb1 with the
calling convention from lib/tdb/include/tdb.h:

int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);

This returns 0 on success and -1 (and only -1) on error.
When running the combined toplevel build with tdb2, I get
the impression that we end up calling tdb_chainlock from
lib/tdb2/tdb2.h:

enum TDB_ERROR tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);

This has a similar calling convention that also compiles
fine in source3, but with an implicit enum->int conversion.
The slight problem I see (assuming we do call tdb_chainlock
returning the enum) is that TDB_ERROR not only is 0 for
success and -1 for failure, but also uses other negative
values:

enum TDB_ERROR {
        TDB_SUCCESS     = 0,    /* No error. */
        TDB_ERR_CORRUPT = -1,   /* We read the db, and it was bogus. */
        TDB_ERR_IO      = -2,   /* We couldn't read/write the db. */
        TDB_ERR_LOCK    = -3,   /* Locking failed. */
        TDB_ERR_OOM     = -4,   /* Out of Memory. */
        TDB_ERR_EXISTS  = -5,   /* The key already exists.  */
        TDB_ERR_NOEXIST = -6,   /* The key does not exist.  */
        TDB_ERR_EINVAL  = -7,   /* You're using it wrong. */
        TDB_ERR_RDONLY  = -8,   /* The database is read-only. */
        TDB_ERR_LAST = TDB_ERR_RDONLY
};

So hypothetical callers checking

if (tdb_chainlock(...) == -1) {
	/* error path */
}

silently would become wrong.

Please, someone explain to me that I am wrong and we do not
call tdb_chainlock from tdb2.h!

Thanks,

Volker

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